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Author SHA1 Message Date
Steven Rostedt (Google)
5fccc7552c ftrace: Add subops logic to allow one ops to manage many 
There are cases where a single system will use a single function callback
to handle multiple users. For example, to allow function_graph tracer to
have multiple users where each can trace their own set of functions, it is
useful to only have one ftrace_ops registered to ftrace that will call a
function by the function_graph tracer to handle the multiplexing with the
different registered  function_graph tracers.

Add a "subop_list" to the ftrace_ops that will hold a list of other
ftrace_ops that the top ftrace_ops will manage.

The function ftrace_startup_subops() that takes the manager ftrace_ops and
a subop ftrace_ops it will manage. If there are no subops with the
ftrace_ops yet, it will copy the ftrace_ops subop filters to the manager
ftrace_ops and register that with ftrace_startup(), and adds the subop to
its subop_list. If the manager ops already has something registered, it
will then merge the new subop filters with what it has and enable the new
functions that covers all the subops it has.

To remove a subop, ftrace_shutdown_subops() is called which will use the
subop_list of the manager ops to rebuild all the functions it needs to
trace, and update the ftrace records to only call the functions it now has
registered. If there are no more functions registered, it will then call
ftrace_shutdown() to disable itself completely.

Note, it is up to the manager ops callback to always make sure that the
subops callbacks are called if its filter matches, as there are times in
the update where the callback could be calling more functions than those
that are currently registered.

This could be updated to handle other systems other than function_graph,
for example, fprobes could use this (but will need an interface to call
ftrace_startup_subops()).

Link: https://lore.kernel.org/linux-trace-kernel/20240603190822.508431129@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-06-04 10:36:38 -04:00
Steven Rostedt (VMware)
26dda5631d ftrace: Allow function_graph tracer to be enabled in instances 
Now that function graph tracing can handle more than one user, allow it to
be enabled in the ftrace instances. Note, the filtering of the functions is
still joined by the top level set_ftrace_filter and friends, as well as the
graph and nograph files.

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509099743.162236.1699959255446248163.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190822.190630762@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-06-04 10:36:28 -04:00
Steven Rostedt (VMware)
37238abe3c ftrace/function_graph: Pass fgraph_ops to function graph callbacks 
Pass the fgraph_ops structure to the function graph callbacks. This will
allow callbacks to add a descriptor to a fgraph_ops private field that wil
be added in the future and use it for the callbacks. This will be useful
when more than one callback can be registered to the function graph tracer.

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509098588.162236.4787930115997357578.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190822.035147698@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-06-04 10:36:22 -04:00
Steven Rostedt (VMware)
2fbb549983 function_graph: Remove logic around ftrace_graph_entry and return 
The function pointers ftrace_graph_entry and ftrace_graph_return are no
longer called via the function_graph tracer. Instead, an array structure is
now used that will allow for multiple users of the function_graph
infrastructure. The variables are still used by the architecture code for
non dynamic ftrace configs, where a test is made against them to see if
they point to the default stub function or not. This is how the static
function tracing knows to call into the function graph tracer
infrastructure or not.

Two new stub functions are made. entry_run() and return_run(). The
ftrace_graph_entry and ftrace_graph_return are set to them respectively
when the function graph tracer is enabled, and this will trigger the
architecture specific function graph code to be executed.

This also requires checking the global_ops hash for all calls into the
function_graph tracer.

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509097408.162236.17387844142114638932.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190821.872127216@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-06-04 10:36:11 -04:00
Masami Hiramatsu (Google)
375bb57292 function_graph: Handle tail calls for stack unwinding 
For the tail-call, there would be 2 or more ftrace_ret_stacks on the
ret_stack, which records "return_to_handler" as the return address except
for the last one.  But on the real stack, there should be 1 entry because
tail-call reuses the return address on the stack and jump to the next
function.

In ftrace_graph_ret_addr() that is used for stack unwinding, skip tail
calls as a real stack unwinder would do.

Link: https://lore.kernel.org/linux-trace-kernel/171509096221.162236.8806372072523195752.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190821.717065217@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-06-04 10:36:05 -04:00
Steven Rostedt (VMware)
7aa1eaef9f function_graph: Allow multiple users to attach to function graph 
Allow for multiple users to attach to function graph tracer at the same
time. Only 16 simultaneous users can attach to the tracer. This is because
there's an array that stores the pointers to the attached fgraph_ops. When
a function being traced is entered, each of the ftrace_ops entryfunc is
called and if it returns non zero, its index into the array will be added
to the shadow stack.

On exit of the function being traced, the shadow stack will contain the
indexes of the ftrace_ops on the array that want their retfunc to be
called.

Because a function may sleep for a long time (if a task sleeps itself),
the return of the function may be literally days later. If the ftrace_ops
is removed, its place on the array is replaced with a ftrace_ops that
contains the stub functions and that will be called when the function
finally returns.

If another ftrace_ops is added that happens to get the same index into the
array, its return function may be called. But that's actually the way
things current work with the old function graph tracer. If one tracer is
removed and another is added, the new one will get the return calls of the
function traced by the previous one, thus this is not a regression. This
can be fixed by adding a counter to each time the array item is updated and
save that on the shadow stack as well, such that it won't be called if the
index saved does not match the index on the array.

Note, being able to filter functions when both are called is not completely
handled yet, but that shouldn't be too hard to manage.

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509096221.162236.8806372072523195752.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190821.555493396@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-06-04 10:35:58 -04:00
Steven Rostedt (VMware)
518d6804a8 function_graph: Add an array structure that will allow multiple callbacks 
Add an array structure that will eventually allow the function graph tracer
to have up to 16 simultaneous callbacks attached. It's an array of 16
fgraph_ops pointers, that is assigned when one is registered. On entry of a
function the entry of the first item in the array is called, and if it
returns zero, then the callback returns non zero if it wants the return
callback to be called on exit of the function.

The array will simplify the process of having more than one callback
attached to the same function, as its index into the array can be stored on
the shadow stack. We need to only save the index, because this will allow
the fgraph_ops to be freed before the function returns (which may happen if
the function call schedule for a long time).

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509095075.162236.8272148192748284581.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190821.392113213@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-06-04 10:35:53 -04:00
Steven Rostedt (VMware)
59e5f04e41 fgraph: Use BUILD_BUG_ON() to make sure we have structures divisible by long 
Instead of using "ALIGN()", use BUILD_BUG_ON() as the structures should
always be divisible by sizeof(long).

Co-developed with Masami Hiramatsu:
Link: https://lore.kernel.org/linux-trace-kernel/171509093949.162236.14518699447151894536.stgit@devnote2
Link: http://lkml.kernel.org/r/20190524111144.GI2589@hirez.programming.kicks-ass.net
Link: https://lore.kernel.org/linux-trace-kernel/20240603190821.232168933@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-06-04 10:35:40 -04:00
Steven Rostedt (VMware)
42675b723b function_graph: Convert ret_stack to a series of longs 
In order to make it possible to have multiple callbacks registered with the
function_graph tracer, the retstack needs to be converted from an array of
ftrace_ret_stack structures to an array of longs. This will allow to store
the list of callbacks on the stack for the return side of the functions.

Link: https://lore.kernel.org/linux-trace-kernel/171509092742.162236.4427737821399314856.stgit@devnote2
Link: https://lore.kernel.org/linux-trace-kernel/20240603190821.073111754@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Guo Ren <guoren@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-06-04 10:35:09 -04:00
Jiri Olsa
aeb8fe0283 bpf: Fix bpf_session_cookie BTF_ID in special_kfunc_set list 
The bpf_session_cookie is unavailable for !CONFIG_FPROBE as reported
by Sebastian [1].

To fix that we remove CONFIG_FPROBE ifdef for session kfuncs, which
is fine, because there's filter for session programs.

Then based on bpf_trace.o dependency:
  obj-$(CONFIG_BPF_EVENTS) += bpf_trace.o

we add bpf_session_cookie BTF_ID in special_kfunc_set list dependency
on CONFIG_BPF_EVENTS.

[1] https://lore.kernel.org/bpf/20240531071557.MvfIqkn7@linutronix.de/T/#m71c6d5ec71db2967288cb79acedc15cc5dbfeec5
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Fixes: 5c919acef8 ("bpf: Add support for kprobe session cookie")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20240531194500.2967187-1-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
 2024-05-31 14:54:48 -07:00
Linus Torvalds
d8ec19857b Including fixes from bpf and netfilter. 
Current release - regressions:
 
   - gro: initialize network_offset in network layer
 
   - tcp: reduce accepted window in NEW_SYN_RECV state
 
 Current release - new code bugs:
 
   - eth: mlx5e: do not use ptp structure for tx ts stats when not initialized
 
   - eth: ice: check for unregistering correct number of devlink params
 
 Previous releases - regressions:
 
   - bpf: Allow delete from sockmap/sockhash only if update is allowed
 
   - sched: taprio: extend minimum interval restriction to entire cycle too
 
   - netfilter: ipset: add list flush to cancel_gc
 
   - ipv4: fix address dump when IPv4 is disabled on an interface
 
   - sock_map: avoid race between sock_map_close and sk_psock_put
 
   - eth: mlx5: use mlx5_ipsec_rx_status_destroy to correctly delete status rules
 
 Previous releases - always broken:
 
   - core: fix __dst_negative_advice() race
 
   - bpf:
     - fix multi-uprobe PID filtering logic
     - fix pkt_type override upon netkit pass verdict
 
   - netfilter: tproxy: bail out if IP has been disabled on the device
 
   - af_unix: annotate data-race around unix_sk(sk)->addr
 
   - eth: mlx5e: fix UDP GSO for encapsulated packets
 
   - eth: idpf: don't enable NAPI and interrupts prior to allocating Rx buffers
 
   - eth: i40e: fully suspend and resume IO operations in EEH case
 
   - eth: octeontx2-pf: free send queue buffers incase of leaf to inner
 
   - eth: ipvlan: dont Use skb->sk in ipvlan_process_v{4,6}_outbound
 
 Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-6.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Paolo Abeni:
 "Including fixes from bpf and netfilter.

  Current release - regressions:

   - gro: initialize network_offset in network layer

   - tcp: reduce accepted window in NEW_SYN_RECV state

  Current release - new code bugs:

   - eth: mlx5e: do not use ptp structure for tx ts stats when not
     initialized

   - eth: ice: check for unregistering correct number of devlink params

  Previous releases - regressions:

   - bpf: Allow delete from sockmap/sockhash only if update is allowed

   - sched: taprio: extend minimum interval restriction to entire cycle
     too

   - netfilter: ipset: add list flush to cancel_gc

   - ipv4: fix address dump when IPv4 is disabled on an interface

   - sock_map: avoid race between sock_map_close and sk_psock_put

   - eth: mlx5: use mlx5_ipsec_rx_status_destroy to correctly delete
     status rules

  Previous releases - always broken:

   - core: fix __dst_negative_advice() race

   - bpf:
       - fix multi-uprobe PID filtering logic
       - fix pkt_type override upon netkit pass verdict

   - netfilter: tproxy: bail out if IP has been disabled on the device

   - af_unix: annotate data-race around unix_sk(sk)->addr

   - eth: mlx5e: fix UDP GSO for encapsulated packets

   - eth: idpf: don't enable NAPI and interrupts prior to allocating Rx
     buffers

   - eth: i40e: fully suspend and resume IO operations in EEH case

   - eth: octeontx2-pf: free send queue buffers incase of leaf to inner

   - eth: ipvlan: dont Use skb->sk in ipvlan_process_v{4,6}_outbound"

* tag 'net-6.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (69 commits)
  netdev: add qstat for csum complete
  ipvlan: Dont Use skb->sk in ipvlan_process_v{4,6}_outbound
  net: ena: Fix redundant device NUMA node override
  ice: check for unregistering correct number of devlink params
  ice: fix 200G PHY types to link speed mapping
  i40e: Fully suspend and resume IO operations in EEH case
  i40e: factoring out i40e_suspend/i40e_resume
  e1000e: move force SMBUS near the end of enable_ulp function
  net: dsa: microchip: fix RGMII error in KSZ DSA driver
  ipv4: correctly iterate over the target netns in inet_dump_ifaddr()
  net: fix __dst_negative_advice() race
  nfc/nci: Add the inconsistency check between the input data length and count
  MAINTAINERS: dwmac: starfive: update Maintainer
  net/sched: taprio: extend minimum interval restriction to entire cycle too
  net/sched: taprio: make q->picos_per_byte available to fill_sched_entry()
  netfilter: nft_fib: allow from forward/input without iif selector
  netfilter: tproxy: bail out if IP has been disabled on the device
  netfilter: nft_payload: skbuff vlan metadata mangle support
  net: ti: icssg-prueth: Fix start counter for ft1 filter
  sock_map: avoid race between sock_map_close and sk_psock_put
  ...
 2024-05-30 08:33:04 -07:00
Jakub Kicinski
2786ae339e bpf-for-netdev 
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2024-05-27

We've added 15 non-merge commits during the last 7 day(s) which contain
a total of 18 files changed, 583 insertions(+), 55 deletions(-).

The main changes are:

1) Fix broken BPF multi-uprobe PID filtering logic which filtered by thread
   while the promise was to filter by process, from Andrii Nakryiko.

2) Fix the recent influx of syzkaller reports to sockmap which triggered
   a locking rule violation by performing a map_delete, from Jakub Sitnicki.

3) Fixes to netkit driver in particular on skb->pkt_type override upon pass
   verdict, from Daniel Borkmann.

4) Fix an integer overflow in resolve_btfids which can wrongly trigger build
   failures, from Friedrich Vock.

5) Follow-up fixes for ARC JIT reported by static analyzers,
   from Shahab Vahedi.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests/bpf: Cover verifier checks for mutating sockmap/sockhash
  Revert "bpf, sockmap: Prevent lock inversion deadlock in map delete elem"
  bpf: Allow delete from sockmap/sockhash only if update is allowed
  selftests/bpf: Add netkit test for pkt_type
  selftests/bpf: Add netkit tests for mac address
  netkit: Fix pkt_type override upon netkit pass verdict
  netkit: Fix setting mac address in l2 mode
  ARC, bpf: Fix issues reported by the static analyzers
  selftests/bpf: extend multi-uprobe tests with USDTs
  selftests/bpf: extend multi-uprobe tests with child thread case
  libbpf: detect broken PID filtering logic for multi-uprobe
  bpf: remove unnecessary rcu_read_{lock,unlock}() in multi-uprobe attach logic
  bpf: fix multi-uprobe PID filtering logic
  bpf: Fix potential integer overflow in resolve_btfids
  MAINTAINERS: Add myself as reviewer of ARM64 BPF JIT
====================

Link: https://lore.kernel.org/r/20240527203551.29712-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2024-05-27 16:26:30 -07:00
Carlos López
e569eb3497 tracing/probes: fix error check in parse_btf_field() 
btf_find_struct_member() might return NULL or an error via the
ERR_PTR() macro. However, its caller in parse_btf_field() only checks
for the NULL condition. Fix this by using IS_ERR() and returning the
error up the stack.

Link: https://lore.kernel.org/all/20240527094351.15687-1-clopez@suse.de/

Fixes: c440adfbe3 ("tracing/probes: Support BTF based data structure field access")
Signed-off-by: Carlos López <clopez@suse.de>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-05-27 21:32:35 +09:00
Andrii Nakryiko
4a8f635a60 bpf: remove unnecessary rcu_read_{lock,unlock}() in multi-uprobe attach logic 
get_pid_task() internally already calls rcu_read_lock() and
rcu_read_unlock(), so there is no point to do this one extra time.

This is a drive-by improvement and has no correctness implications.

Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240521163401.3005045-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
 2024-05-25 10:46:02 -07:00
Andrii Nakryiko
46ba0e49b6 bpf: fix multi-uprobe PID filtering logic 
Current implementation of PID filtering logic for multi-uprobes in
uprobe_prog_run() is filtering down to exact *thread*, while the intent
for PID filtering it to filter by *process* instead. The check in
uprobe_prog_run() also differs from the analogous one in
uprobe_multi_link_filter() for some reason. The latter is correct,
checking task->mm, not the task itself.

Fix the check in uprobe_prog_run() to perform the same task->mm check.

While doing this, we also update get_pid_task() use to use PIDTYPE_TGID
type of lookup, given the intent is to get a representative task of an
entire process. This doesn't change behavior, but seems more logical. It
would hold task group leader task now, not any random thread task.

Last but not least, given multi-uprobe support is half-broken due to
this PID filtering logic (depending on whether PID filtering is
important or not), we need to make it easy for user space consumers
(including libbpf) to easily detect whether PID filtering logic was
already fixed.

We do it here by adding an early check on passed pid parameter. If it's
negative (and so has no chance of being a valid PID), we return -EINVAL.
Previous behavior would eventually return -ESRCH ("No process found"),
given there can't be any process with negative PID. This subtle change
won't make any practical change in behavior, but will allow applications
to detect PID filtering fixes easily. Libbpf fixes take advantage of
this in the next patch.

Cc: stable@vger.kernel.org
Acked-by: Jiri Olsa <jolsa@kernel.org>
Fixes: b733eeade4 ("bpf: Add pid filter support for uprobe_multi link")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240521163401.3005045-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
 2024-05-25 10:46:02 -07:00
Andrii Nakryiko
699646734a uprobes: prevent mutex_lock() under rcu_read_lock() 
Recent changes made uprobe_cpu_buffer preparation lazy, and moved it
deeper into __uprobe_trace_func(). This is problematic because
__uprobe_trace_func() is called inside rcu_read_lock()/rcu_read_unlock()
block, which then calls prepare_uprobe_buffer() -> uprobe_buffer_get() ->
mutex_lock(&ucb->mutex), leading to a splat about using mutex under
non-sleepable RCU:

  BUG: sleeping function called from invalid context at kernel/locking/mutex.c:585
   in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 98231, name: stress-ng-sigq
   preempt_count: 0, expected: 0
   RCU nest depth: 1, expected: 0
   ...
   Call Trace:
    <TASK>
    dump_stack_lvl+0x3d/0xe0
    __might_resched+0x24c/0x270
    ? prepare_uprobe_buffer+0xd5/0x1d0
    __mutex_lock+0x41/0x820
    ? ___perf_sw_event+0x206/0x290
    ? __perf_event_task_sched_in+0x54/0x660
    ? __perf_event_task_sched_in+0x54/0x660
    prepare_uprobe_buffer+0xd5/0x1d0
    __uprobe_trace_func+0x4a/0x140
    uprobe_dispatcher+0x135/0x280
    ? uprobe_dispatcher+0x94/0x280
    uprobe_notify_resume+0x650/0xec0
    ? atomic_notifier_call_chain+0x21/0x110
    ? atomic_notifier_call_chain+0xf8/0x110
    irqentry_exit_to_user_mode+0xe2/0x1e0
    asm_exc_int3+0x35/0x40
   RIP: 0033:0x7f7e1d4da390
   Code: 33 04 00 0f 1f 80 00 00 00 00 f3 0f 1e fa b9 01 00 00 00 e9 b2 fc ff ff 66 90 f3 0f 1e fa 31 c9 e9 a5 fc ff ff 0f 1f 44 00 00 <cc> 0f 1e fa b8 27 00 00 00 0f 05 c3 0f 1f 40 00 f3 0f 1e fa b8 6e
   RSP: 002b:00007ffd2abc3608 EFLAGS: 00000246
   RAX: 0000000000000000 RBX: 0000000076d325f1 RCX: 0000000000000000
   RDX: 0000000076d325f1 RSI: 000000000000000a RDI: 00007ffd2abc3690
   RBP: 000000000000000a R08: 00017fb700000000 R09: 00017fb700000000
   R10: 00017fb700000000 R11: 0000000000000246 R12: 0000000000017ff2
   R13: 00007ffd2abc3610 R14: 0000000000000000 R15: 00007ffd2abc3780
    </TASK>

Luckily, it's easy to fix by moving prepare_uprobe_buffer() to be called
slightly earlier: into uprobe_trace_func() and uretprobe_trace_func(), outside
of RCU locked section. This still keeps this buffer preparation lazy and helps
avoid the overhead when it's not needed. E.g., if there is only BPF uprobe
handler installed on a given uprobe, buffer won't be initialized.

Note, the other user of prepare_uprobe_buffer(), __uprobe_perf_func(), is not
affected, as it doesn't prepare buffer under RCU read lock.

Link: https://lore.kernel.org/all/20240521053017.3708530-1-andrii@kernel.org/

Fixes: 1b8f85defb ("uprobes: prepare uprobe args buffer lazily")
Reported-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-05-24 07:44:44 +09:00
Linus Torvalds
404001ddf3 tracing: Minor last minute fixes 
- Fix a very tight race between the ring buffer readers and resizing
   the ring buffer.
 
 - Correct some stale comments in the ring buffer code.
 
 - Fix kernel-doc in the rv code.
 
 - Add a MODULE_DESCRIPTION to preemptirq_delay_test
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Merge tag 'trace-fixes-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Minor last minute fixes:

   - Fix a very tight race between the ring buffer readers and resizing
     the ring buffer

   - Correct some stale comments in the ring buffer code

   - Fix kernel-doc in the rv code

   - Add a MODULE_DESCRIPTION to preemptirq_delay_test"

* tag 'trace-fixes-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  rv: Update rv_en(dis)able_monitor doc to match kernel-doc
  tracing: Add MODULE_DESCRIPTION() to preemptirq_delay_test
  ring-buffer: Fix a race between readers and resize checks
  ring-buffer: Correct stale comments related to non-consuming readers
 2024-05-23 12:36:38 -07:00
Steven Rostedt (Google)
2c92ca849f tracing/treewide: Remove second parameter of __assign_str() 
With the rework of how the __string() handles dynamic strings where it
saves off the source string in field in the helper structure[1], the
assignment of that value to the trace event field is stored in the helper
value and does not need to be passed in again.

This means that with:

  __string(field, mystring)

Which use to be assigned with __assign_str(field, mystring), no longer
needs the second parameter and it is unused. With this, __assign_str()
will now only get a single parameter.

There's over 700 users of __assign_str() and because coccinelle does not
handle the TRACE_EVENT() macro I ended up using the following sed script:

  git grep -l __assign_str | while read a ; do
      sed -e 's/\(__assign_str([^,]*[^ ,]\) *,[^;]*/\1)/' $a > /tmp/test-file;
      mv /tmp/test-file $a;
  done

I then searched for __assign_str() that did not end with ';' as those
were multi line assignments that the sed script above would fail to catch.

Note, the same updates will need to be done for:

  __assign_str_len()
  __assign_rel_str()
  __assign_rel_str_len()

I tested this with both an allmodconfig and an allyesconfig (build only for both).

[1] https://lore.kernel.org/linux-trace-kernel/20240222211442.634192653@goodmis.org/

Link: https://lore.kernel.org/linux-trace-kernel/20240516133454.681ba6a0@rorschach.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Christian König <christian.koenig@amd.com> for the amdgpu parts.
Acked-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> #for
Acked-by: Rafael J. Wysocki <rafael@kernel.org> # for thermal
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Darrick J. Wong <djwong@kernel.org>	# xfs
Tested-by: Guenter Roeck <linux@roeck-us.net>
 2024-05-22 20:14:47 -04:00
Yang Li
1e8b7b3dbb rv: Update rv_en(dis)able_monitor doc to match kernel-doc 
The patch updates the function documentation comment for
rv_en(dis)able_monitor to adhere to the kernel-doc specification.

Link: https://lore.kernel.org/linux-trace-kernel/20240520054239.61784-1-yang.lee@linux.alibaba.com

Fixes: 102227b970 ("rv: Add Runtime Verification (RV) interface")
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-05-21 19:03:35 -04:00
Jeff Johnson
23748e3e0f tracing: Add MODULE_DESCRIPTION() to preemptirq_delay_test 
Fix the 'make W=1' warning:

WARNING: modpost: missing MODULE_DESCRIPTION() in kernel/trace/preemptirq_delay_test.o

Link: https://lore.kernel.org/linux-trace-kernel/20240518-md-preemptirq_delay_test-v1-1-387d11b30d85@quicinc.com

Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: f96e8577da ("lib: Add module for testing preemptoff/irqsoff latency tracers")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-05-21 19:03:35 -04:00
Petr Pavlu
c2274b908d ring-buffer: Fix a race between readers and resize checks 
The reader code in rb_get_reader_page() swaps a new reader page into the
ring buffer by doing cmpxchg on old->list.prev->next to point it to the
new page. Following that, if the operation is successful,
old->list.next->prev gets updated too. This means the underlying
doubly-linked list is temporarily inconsistent, page->prev->next or
page->next->prev might not be equal back to page for some page in the
ring buffer.

The resize operation in ring_buffer_resize() can be invoked in parallel.
It calls rb_check_pages() which can detect the described inconsistency
and stop further tracing:

[  190.271762] ------------[ cut here ]------------
[  190.271771] WARNING: CPU: 1 PID: 6186 at kernel/trace/ring_buffer.c:1467 rb_check_pages.isra.0+0x6a/0xa0
[  190.271789] Modules linked in: [...]
[  190.271991] Unloaded tainted modules: intel_uncore_frequency(E):1 skx_edac(E):1
[  190.272002] CPU: 1 PID: 6186 Comm: cmd.sh Kdump: loaded Tainted: G            E      6.9.0-rc6-default #5 158d3e1e6d0b091c34c3b96bfd99a1c58306d79f
[  190.272011] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552c-rebuilt.opensuse.org 04/01/2014
[  190.272015] RIP: 0010:rb_check_pages.isra.0+0x6a/0xa0
[  190.272023] Code: [...]
[  190.272028] RSP: 0018:ffff9c37463abb70 EFLAGS: 00010206
[  190.272034] RAX: ffff8eba04b6cb80 RBX: 0000000000000007 RCX: ffff8eba01f13d80
[  190.272038] RDX: ffff8eba01f130c0 RSI: ffff8eba04b6cd00 RDI: ffff8eba0004c700
[  190.272042] RBP: ffff8eba0004c700 R08: 0000000000010002 R09: 0000000000000000
[  190.272045] R10: 00000000ffff7f52 R11: ffff8eba7f600000 R12: ffff8eba0004c720
[  190.272049] R13: ffff8eba00223a00 R14: 0000000000000008 R15: ffff8eba067a8000
[  190.272053] FS:  00007f1bd64752c0(0000) GS:ffff8eba7f680000(0000) knlGS:0000000000000000
[  190.272057] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  190.272061] CR2: 00007f1bd6662590 CR3: 000000010291e001 CR4: 0000000000370ef0
[  190.272070] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  190.272073] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  190.272077] Call Trace:
[  190.272098]  <TASK>
[  190.272189]  ring_buffer_resize+0x2ab/0x460
[  190.272199]  __tracing_resize_ring_buffer.part.0+0x23/0xa0
[  190.272206]  tracing_resize_ring_buffer+0x65/0x90
[  190.272216]  tracing_entries_write+0x74/0xc0
[  190.272225]  vfs_write+0xf5/0x420
[  190.272248]  ksys_write+0x67/0xe0
[  190.272256]  do_syscall_64+0x82/0x170
[  190.272363]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  190.272373] RIP: 0033:0x7f1bd657d263
[  190.272381] Code: [...]
[  190.272385] RSP: 002b:00007ffe72b643f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[  190.272391] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f1bd657d263
[  190.272395] RDX: 0000000000000002 RSI: 0000555a6eb538e0 RDI: 0000000000000001
[  190.272398] RBP: 0000555a6eb538e0 R08: 000000000000000a R09: 0000000000000000
[  190.272401] R10: 0000555a6eb55190 R11: 0000000000000246 R12: 00007f1bd6662500
[  190.272404] R13: 0000000000000002 R14: 00007f1bd6667c00 R15: 0000000000000002
[  190.272412]  </TASK>
[  190.272414] ---[ end trace 0000000000000000 ]---

Note that ring_buffer_resize() calls rb_check_pages() only if the parent
trace_buffer has recording disabled. Recent commit d78ab79270
("tracing: Stop current tracer when resizing buffer") causes that it is
now always the case which makes it more likely to experience this issue.

The window to hit this race is nonetheless very small. To help
reproducing it, one can add a delay loop in rb_get_reader_page():

 ret = rb_head_page_replace(reader, cpu_buffer->reader_page);
 if (!ret)
 	goto spin;
 for (unsigned i = 0; i < 1U << 26; i++)  /* inserted delay loop */
 	__asm__ __volatile__ ("" : : : "memory");
 rb_list_head(reader->list.next)->prev = &cpu_buffer->reader_page->list;

.. and then run the following commands on the target system:

 echo 1 > /sys/kernel/tracing/events/sched/sched_switch/enable
 while true; do
 	echo 16 > /sys/kernel/tracing/buffer_size_kb; sleep 0.1
 	echo 8 > /sys/kernel/tracing/buffer_size_kb; sleep 0.1
 done &
 while true; do
 	for i in /sys/kernel/tracing/per_cpu/*; do
 		timeout 0.1 cat $i/trace_pipe; sleep 0.2
 	done
 done

To fix the problem, make sure ring_buffer_resize() doesn't invoke
rb_check_pages() concurrently with a reader operating on the same
ring_buffer_per_cpu by taking its cpu_buffer->reader_lock.

Link: https://lore.kernel.org/linux-trace-kernel/20240517134008.24529-3-petr.pavlu@suse.com

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 659f451ff2 ("ring-buffer: Add integrity check at end of iter read")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
[ Fixed whitespace ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-05-21 19:03:35 -04:00
Petr Pavlu
ea70a9628e ring-buffer: Correct stale comments related to non-consuming readers 
Adjust the following code documentation:

* Kernel-doc comments for ring_buffer_read_prepare() and
  ring_buffer_read_finish() mention that recording to the ring buffer is
  disabled when the read is active. Remove mention of this restriction
  because it was already lifted in commit 1039221cc2 ("ring-buffer: Do
  not disable recording when there is an iterator").

* Function ring_buffer_read_finish() performs a self-check of the
  ring-buffer by locking cpu_buffer->reader_lock and then calling
  rb_check_pages(). The preceding comment explains that the lock is
  needed because rb_check_pages() clears the HEAD flag required by
  readers which might be running in parallel. Remove this explanation
  because commit 8843e06f67 ("ring-buffer: Handle race between
  rb_move_tail and rb_check_pages") simplified the function so it no
  longer resets the mentioned flag. Nonetheless, the lock is still
  needed because a reader swapping a page into the ring buffer can make
  the underlying doubly-linked list temporarily inconsistent.

This is a non-functional change.

Link: https://lore.kernel.org/linux-trace-kernel/20240517134008.24529-2-petr.pavlu@suse.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-05-21 19:03:35 -04:00
Linus Torvalds
eb6a9339ef Mainly singleton patches, documented in their respective changelogs. 
Notable series include:
 
 - Some maintenance and performance work for ocfs2 in Heming Zhao's
   series "improve write IO performance when fragmentation is high".
 
 - Some ocfs2 bugfixes from Su Yue in the series "ocfs2 bugs fixes
   exposed by fstests".
 
 - kfifo header rework from Andy Shevchenko in the series "kfifo: Clean
   up kfifo.h".
 
 - GDB script fixes from Florian Rommel in the series "scripts/gdb: Fixes
   for $lx_current and $lx_per_cpu".
 
 - After much discussion, a coding-style update from Barry Song
   explaining one reason why inline functions are preferred over macros.
   The series is "codingstyle: avoid unused parameters for a function-like
   macro".
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Merge tag 'mm-nonmm-stable-2024-05-19-11-56' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-mm updates from Andrew Morton:
 "Mainly singleton patches, documented in their respective changelogs.
  Notable series include:

   - Some maintenance and performance work for ocfs2 in Heming Zhao's
     series "improve write IO performance when fragmentation is high".

   - Some ocfs2 bugfixes from Su Yue in the series "ocfs2 bugs fixes
     exposed by fstests".

   - kfifo header rework from Andy Shevchenko in the series "kfifo:
     Clean up kfifo.h".

   - GDB script fixes from Florian Rommel in the series "scripts/gdb:
     Fixes for $lx_current and $lx_per_cpu".

   - After much discussion, a coding-style update from Barry Song
     explaining one reason why inline functions are preferred over
     macros. The series is "codingstyle: avoid unused parameters for a
     function-like macro""

* tag 'mm-nonmm-stable-2024-05-19-11-56' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (62 commits)
  fs/proc: fix softlockup in __read_vmcore
  nilfs2: convert BUG_ON() in nilfs_finish_roll_forward() to WARN_ON()
  scripts: checkpatch: check unused parameters for function-like macro
  Documentation: coding-style: ask function-like macros to evaluate parameters
  nilfs2: use __field_struct() for a bitwise field
  selftests/kcmp: remove unused open mode
  nilfs2: remove calls to folio_set_error() and folio_clear_error()
  kernel/watchdog_perf.c: tidy up kerneldoc
  watchdog: allow nmi watchdog to use raw perf event
  watchdog: handle comma separated nmi_watchdog command line
  nilfs2: make superblock data array index computation sparse friendly
  squashfs: remove calls to set the folio error flag
  squashfs: convert squashfs_symlink_read_folio to use folio APIs
  scripts/gdb: fix detection of current CPU in KGDB
  scripts/gdb: make get_thread_info accept pointers
  scripts/gdb: fix parameter handling in $lx_per_cpu
  scripts/gdb: fix failing KGDB detection during probe
  kfifo: don't use "proxy" headers
  media: stih-cec: add missing io.h
  media: rc: add missing io.h
  ...
 2024-05-19 14:02:03 -07:00
Linus Torvalds
fa3889d970 user-event updates for v6.10: 
- Minor update to the user_events interface
   The ABI of creating a user event states that the fields
   are separated by semicolons, and spaces should be ignored.
   But the parsing expected at least one space to be there (which was incorrect).
   Fix the reading of the string to handle fields separated by
   semicolons but no space between them.
 
   This does extend the API sightly as now "field;field" will now be
   parsed and not cause an error. But it should not cause any regressions
   as no logic should expect it to fail.
 
   Note, that the logic that parses the event fields to create the
   trace_event works with no spaces after the semi-colon. It is
   the logic that tests against existing events that is inconsistent.
   This causes registering an event without using spaces to succeed
   if it doesn't exist, but makes the same call that tries to register
   to the same event, but doesn't use spaces, fail.
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Merge tag 'trace-user-events-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing user-event updates from Steven Rostedt:

 - Minor update to the user_events interface

  The ABI of creating a user event states that the fields are separated
  by semicolons, and spaces should be ignored.

  But the parsing expected at least one space to be there (which was
  incorrect). Fix the reading of the string to handle fields separated
  by semicolons but no space between them.

  This does extend the API sightly as now "field;field" will now be
  parsed and not cause an error. But it should not cause any regressions
  as no logic should expect it to fail.

  Note, that the logic that parses the event fields to create the
  trace_event works with no spaces after the semi-colon. It is
  the logic that tests against existing events that is inconsistent.
  This causes registering an event without using spaces to succeed
  if it doesn't exist, but makes the same call that tries to register
  to the same event, but doesn't use spaces, fail.

* tag 'trace-user-events-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  selftests/user_events: Add non-spacing separator check
  tracing/user_events: Fix non-spaced field matching
 2024-05-17 18:46:30 -07:00
Linus Torvalds
53683e4080 tracing ring buffer updates for v6.10: 
- Add ring_buffer memory mappings
 
   The tracing ring buffer was created based on being mostly used with the
   splice system call. It is broken up into page ordered sub-buffers and the
   reader swaps a new sub-buffer with an existing sub-buffer that's part
   of the write buffer. It then has total access to the swapped out
   sub-buffer and can do copyless movements of the memory into other mediums
   (file system, network, etc).
 
   The buffer is great for passing around the ring buffer contents in the
   kernel, but is not so good for when the consumer is the user space task
   itself.
 
   A new interface is added that allows user space to memory map the ring
   buffer. It will get all the write sub-buffers as well as reader sub-buffer
   (that is not written to). It can send an ioctl to change which sub-buffer
   is the new reader sub-buffer.
 
   The ring buffer is read only to user space. It only needs to call the
   ioctl when it is finished with a sub-buffer and needs a new sub-buffer
   that the writer will not write over.
 
   A self test program was also created for testing and can be used as
   an example for the interface to user space. The libtracefs (external
   to the kernel) also has code that interacts with this, although it is
   disabled until the interface is in a official release. It can be enabled
   by compiling the library with a special flag. This was used for testing
   applications that perform better with the buffer being mapped.
 
   Memory mapped buffers have limitations. The main one is that it can not be
   used with the snapshot logic. If the buffer is mapped, snapshots will be
   disabled. If any logic is set to trigger snapshots on a buffer, that
   buffer will not be allowed to be mapped.
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Merge tag 'trace-ringbuffer-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing ring buffer updates from Steven Rostedt:
 "Add ring_buffer memory mappings.

  The tracing ring buffer was created based on being mostly used with
  the splice system call. It is broken up into page ordered sub-buffers
  and the reader swaps a new sub-buffer with an existing sub-buffer
  that's part of the write buffer. It then has total access to the
  swapped out sub-buffer and can do copyless movements of the memory
  into other mediums (file system, network, etc).

  The buffer is great for passing around the ring buffer contents in the
  kernel, but is not so good for when the consumer is the user space
  task itself.

  A new interface is added that allows user space to memory map the ring
  buffer. It will get all the write sub-buffers as well as reader
  sub-buffer (that is not written to). It can send an ioctl to change
  which sub-buffer is the new reader sub-buffer.

  The ring buffer is read only to user space. It only needs to call the
  ioctl when it is finished with a sub-buffer and needs a new sub-buffer
  that the writer will not write over.

  A self test program was also created for testing and can be used as an
  example for the interface to user space. The libtracefs (external to
  the kernel) also has code that interacts with this, although it is
  disabled until the interface is in a official release. It can be
  enabled by compiling the library with a special flag. This was used
  for testing applications that perform better with the buffer being
  mapped.

  Memory mapped buffers have limitations. The main one is that it can
  not be used with the snapshot logic. If the buffer is mapped,
  snapshots will be disabled. If any logic is set to trigger snapshots
  on a buffer, that buffer will not be allowed to be mapped"

* tag 'trace-ringbuffer-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Add cast to unsigned long addr passed to virt_to_page()
  ring-buffer: Have mmapped ring buffer keep track of missed events
  ring-buffer/selftest: Add ring-buffer mapping test
  Documentation: tracing: Add ring-buffer mapping
  tracing: Allow user-space mapping of the ring-buffer
  ring-buffer: Introducing ring-buffer mapping functions
  ring-buffer: Allocate sub-buffers with __GFP_COMP
 2024-05-17 18:40:37 -07:00
Linus Torvalds
594d28157f tracing cleanups for v6.10: 
- Removed unused ftrace_direct_funcs variables
 
 - Fix a possible NULL pointer dereference race in eventfs
 
 - Update do_div() usage in trace event benchmark test
 
 - Speedup direct function registration with asynchronous RCU callback.
   The synchronization was done in the registration code and this
   caused delays when registering direct callbacks. Move the freeing
   to a call_rcu() that will prevent delaying of the registering.
 
 - Replace simple_strtoul() usage with kstrtoul()
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Merge tag 'trace-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing updates from Steven Rostedt:

 - Remove unused ftrace_direct_funcs variables

 - Fix a possible NULL pointer dereference race in eventfs

 - Update do_div() usage in trace event benchmark test

 - Speedup direct function registration with asynchronous RCU callback.

   The synchronization was done in the registration code and this caused
   delays when registering direct callbacks. Move the freeing to a
   call_rcu() that will prevent delaying of the registering.

 - Replace simple_strtoul() usage with kstrtoul()

* tag 'trace-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  eventfs: Fix a possible null pointer dereference in eventfs_find_events()
  ftrace: Fix possible use-after-free issue in ftrace_location()
  ftrace: Remove unused global 'ftrace_direct_func_count'
  ftrace: Remove unused list 'ftrace_direct_funcs'
  tracing: Improve benchmark test performance by using do_div()
  ftrace: Use asynchronous grace period for register_ftrace_direct()
  ftrace: Replaces simple_strtoul in ftrace
 2024-05-17 18:34:27 -07:00
Linus Torvalds
70a663205d Probes updates for v6.10: 
- tracing/probes: Adding new pseudo-types %pd and %pD support for dumping
   dentry name from 'struct dentry *' and file name from 'struct file *'.
 
 - uprobes: Some performance optimizations have been done.
  . Speed up the BPF uprobe event by delaying the fetching of the uprobe
    event arguments that are not used in BPF.
  . Avoid locking by speculatively checking whether uprobe event is valid.
  . Reduce lock contention by using read/write_lock instead of spinlock for
    uprobe list operation. This improved BPF uprobe benchmark result 43% on
    average.
 
 - rethook: Removes non-fatal warning messages when tracing stack from BPF
   and skip rcu_is_watching() validation in rethook if possible.
 
 - objpool: Optimizing objpool (which is used by kretprobes and fprobe as
   rethook backend storage) by inlining functions and avoid caching nr_cpu_ids
   because it is a const value.
 
 - fprobe: Add entry/exit callbacks types (code cleanup)
 - kprobes: Check ftrace was killed in kprobes if it uses ftrace.
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Merge tag 'probes-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes updates from Masami Hiramatsu:

 - tracing/probes: Add new pseudo-types %pd and %pD support for dumping
   dentry name from 'struct dentry *' and file name from 'struct file *'

 - uprobes performance optimizations:
    - Speed up the BPF uprobe event by delaying the fetching of the
      uprobe event arguments that are not used in BPF
    - Avoid locking by speculatively checking whether uprobe event is
      valid
    - Reduce lock contention by using read/write_lock instead of
      spinlock for uprobe list operation. This improved BPF uprobe
      benchmark result 43% on average

 - rethook: Remove non-fatal warning messages when tracing stack from
   BPF and skip rcu_is_watching() validation in rethook if possible

 - objpool: Optimize objpool (which is used by kretprobes and fprobe as
   rethook backend storage) by inlining functions and avoid caching
   nr_cpu_ids because it is a const value

 - fprobe: Add entry/exit callbacks types (code cleanup)

 - kprobes: Check ftrace was killed in kprobes if it uses ftrace

* tag 'probes-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  kprobe/ftrace: bail out if ftrace was killed
  selftests/ftrace: Fix required features for VFS type test case
  objpool: cache nr_possible_cpus() and avoid caching nr_cpu_ids
  objpool: enable inlining objpool_push() and objpool_pop() operations
  rethook: honor CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING in rethook_try_get()
  ftrace: make extra rcu_is_watching() validation check optional
  uprobes: reduce contention on uprobes_tree access
  rethook: Remove warning messages printed for finding return address of a frame.
  fprobe: Add entry/exit callbacks types
  selftests/ftrace: add fprobe test cases for VFS type "%pd" and "%pD"
  selftests/ftrace: add kprobe test cases for VFS type "%pd" and "%pD"
  Documentation: tracing: add new type '%pd' and '%pD' for kprobe
  tracing/probes: support '%pD' type for print struct file's name
  tracing/probes: support '%pd' type for print struct dentry's name
  uprobes: add speculative lockless system-wide uprobe filter check
  uprobes: prepare uprobe args buffer lazily
  uprobes: encapsulate preparation of uprobe args buffer
 2024-05-17 18:29:30 -07:00
Linus Torvalds
91b6163be4 sysctl changes for v6.10-rc1 
Summary
 * Removed sentinel elements from ctl_table structs in kernel/*
 
   Removing sentinels in ctl_table arrays reduces the build time size and
   runtime memory consumed by ~64 bytes per array. Removals for net/, io_uring/,
   mm/, ipc/ and security/ are set to go into mainline through their respective
   subsystems making the next release the most likely place where the final
   series that removes the check for proc_name == NULL will land. This PR adds
   to removals already in arch/, drivers/ and fs/.
 
 * Adjusted ctl_table definitions and references to allow constification
 
   Adjustments:
     - Removing unused ctl_table function arguments
     - Moving non-const elements from ctl_table to ctl_table_header
     - Making ctl_table pointers const in ctl_table_root structure
 
   Making the static ctl_table structs const will increase safety by keeping the
   pointers to proc_handler functions in .rodata. Though no ctl_tables where
   made const in this PR, the ground work for making that possible has started
   with these changes sent by Thomas Weißschuh.
 
 Testing
 * These changes went into linux-next after v6.9-rc4; giving it a good month of
   testing.
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Merge tag 'sysctl-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl

Pull sysctl updates from Joel Granados:

 - Remove sentinel elements from ctl_table structs in kernel/*

   Removing sentinels in ctl_table arrays reduces the build time size
   and runtime memory consumed by ~64 bytes per array. Removals for
   net/, io_uring/, mm/, ipc/ and security/ are set to go into mainline
   through their respective subsystems making the next release the most
   likely place where the final series that removes the check for
   proc_name == NULL will land.

   This adds to removals already in arch/, drivers/ and fs/.

 - Adjust ctl_table definitions and references to allow constification
     - Remove unused ctl_table function arguments
     - Move non-const elements from ctl_table to ctl_table_header
     - Make ctl_table pointers const in ctl_table_root structure

   Making the static ctl_table structs const will increase safety by
   keeping the pointers to proc_handler functions in .rodata. Though no
   ctl_tables where made const in this PR, the ground work for making
   that possible has started with these changes sent by Thomas
   Weißschuh.

* tag 'sysctl-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl:
  sysctl: drop now unnecessary out-of-bounds check
  sysctl: move sysctl type to ctl_table_header
  sysctl: drop sysctl_is_perm_empty_ctl_table
  sysctl: treewide: constify argument ctl_table_root::permissions(table)
  sysctl: treewide: drop unused argument ctl_table_root::set_ownership(table)
  bpf: Remove the now superfluous sentinel elements from ctl_table array
  delayacct: Remove the now superfluous sentinel elements from ctl_table array
  kprobes: Remove the now superfluous sentinel elements from ctl_table array
  printk: Remove the now superfluous sentinel elements from ctl_table array
  scheduler: Remove the now superfluous sentinel elements from ctl_table array
  seccomp: Remove the now superfluous sentinel elements from ctl_table array
  timekeeping: Remove the now superfluous sentinel elements from ctl_table array
  ftrace: Remove the now superfluous sentinel elements from ctl_table array
  umh: Remove the now superfluous sentinel elements from ctl_table array
  kernel misc: Remove the now superfluous sentinel elements from ctl_table array
 2024-05-17 17:31:24 -07:00
Stephen Brennan
1a7d0890dd kprobe/ftrace: bail out if ftrace was killed 
If an error happens in ftrace, ftrace_kill() will prevent disarming
kprobes. Eventually, the ftrace_ops associated with the kprobes will be
freed, yet the kprobes will still be active, and when triggered, they
will use the freed memory, likely resulting in a page fault and panic.

This behavior can be reproduced quite easily, by creating a kprobe and
then triggering a ftrace_kill(). For simplicity, we can simulate an
ftrace error with a kernel module like [1]:

[1]: https://github.com/brenns10/kernel_stuff/tree/master/ftrace_killer

  sudo perf probe --add commit_creds
  sudo perf trace -e probe:commit_creds
  # In another terminal
  make
  sudo insmod ftrace_killer.ko  # calls ftrace_kill(), simulating bug
  # Back to perf terminal
  # ctrl-c
  sudo perf probe --del commit_creds

After a short period, a page fault and panic would occur as the kprobe
continues to execute and uses the freed ftrace_ops. While ftrace_kill()
is supposed to be used only in extreme circumstances, it is invoked in
FTRACE_WARN_ON() and so there are many places where an unexpected bug
could be triggered, yet the system may continue operating, possibly
without the administrator noticing. If ftrace_kill() does not panic the
system, then we should do everything we can to continue operating,
rather than leave a ticking time bomb.

Link: https://lore.kernel.org/all/20240501162956.229427-1-stephen.s.brennan@oracle.com/

Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-05-16 07:23:30 +09:00
Linus Torvalds
a49468240e Modules changes for v6.10-rc1 
Finally something fun. Mike Rapoport does some cleanup to allow us to
 take out module_alloc() out of modules into a new paint shedded execmem_alloc()
 and execmem_free() so to make emphasis these helpers are actually used outside
 of modules. It starts with a no-functional changes API rename / placeholders
 to then allow architectures to define their requirements into a new shiny
 struct execmem_info with ranges, and requirements for those ranges. Archs
 now can intitialize this execmem_info as the last part of mm_core_init() if
 they have to diverge from the norm. Each range is a known type clearly
 articulated and spelled out in enum execmem_type.
 
 Although a lot of this is major cleanup and prep work for future enhancements an
 immediate clear gain is we get to enable KPROBES without MODULES now. That is
 ultimately what motiviated to pick this work up again, now with smaller goal as
 concrete stepping stone.
 
 This has been sitting on linux-next for a little less than a month, a few issues
 were found already and fixed, in particular an odd mips boot issue. Arch folks
 reviewed the code too. This is ready for wider exposure and testing.
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Merge tag 'modules-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull modules updates from Luis Chamberlain:
 "Finally something fun. Mike Rapoport does some cleanup to allow us to
  take out module_alloc() out of modules into a new paint shedded
  execmem_alloc() and execmem_free() so to make emphasis these helpers
  are actually used outside of modules.

  It starts with a non-functional changes API rename / placeholders to
  then allow architectures to define their requirements into a new shiny
  struct execmem_info with ranges, and requirements for those ranges.

  Archs now can intitialize this execmem_info as the last part of
  mm_core_init() if they have to diverge from the norm. Each range is a
  known type clearly articulated and spelled out in enum execmem_type.

  Although a lot of this is major cleanup and prep work for future
  enhancements an immediate clear gain is we get to enable KPROBES
  without MODULES now. That is ultimately what motiviated to pick this
  work up again, now with smaller goal as concrete stepping stone"

* tag 'modules-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
  bpf: remove CONFIG_BPF_JIT dependency on CONFIG_MODULES of
  kprobes: remove dependency on CONFIG_MODULES
  powerpc: use CONFIG_EXECMEM instead of CONFIG_MODULES where appropriate
  x86/ftrace: enable dynamic ftrace without CONFIG_MODULES
  arch: make execmem setup available regardless of CONFIG_MODULES
  powerpc: extend execmem_params for kprobes allocations
  arm64: extend execmem_info for generated code allocations
  riscv: extend execmem_params for generated code allocations
  mm/execmem, arch: convert remaining overrides of module_alloc to execmem
  mm/execmem, arch: convert simple overrides of module_alloc to execmem
  mm: introduce execmem_alloc() and execmem_free()
  module: make module_memory_{alloc,free} more self-contained
  sparc: simplify module_alloc()
  nios2: define virtual address space for modules
  mips: module: rename MODULE_START to MODULES_VADDR
  arm64: module: remove unneeded call to kasan_alloc_module_shadow()
  kallsyms: replace deprecated strncpy with strscpy
  module: allow UNUSED_KSYMS_WHITELIST to be relative against objtree.
 2024-05-15 14:05:08 -07:00
Steven Rostedt (Google)
b9c6820f02 ring-buffer: Add cast to unsigned long addr passed to virt_to_page() 
The sub-buffer pages are held in an unsigned long array, and when it is
passed to virt_to_page() a cast is needed.

Link: https://lore.kernel.org/all/20240515124808.06279d04@canb.auug.org.au/
Link: https://lore.kernel.org/linux-trace-kernel/20240515010558.4abaefdd@rorschach.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 117c39200d ("ring-buffer: Introducing ring-buffer mapping functions")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-05-15 01:28:42 -04:00
Linus Torvalds
1b294a1f35 Networking changes for 6.10. 
Core & protocols
 ----------------
 
  - Complete rework of garbage collection of AF_UNIX sockets.
    AF_UNIX is prone to forming reference count cycles due to fd passing
    functionality. New method based on Tarjan's Strongly Connected Components
    algorithm should be both faster and remove a lot of workarounds
    we accumulated over the years.
 
  - Add TCP fraglist GRO support, allowing chaining multiple TCP packets
    and forwarding them together. Useful for small switches / routers which
    lack basic checksum offload in some scenarios (e.g. PPPoE).
 
  - Support using SMP threads for handling packet backlog i.e. packet
    processing from software interfaces and old drivers which don't
    use NAPI. This helps move the processing out of the softirq jumble.
 
  - Continue work of converting from rtnl lock to RCU protection.
    Don't require rtnl lock when reading: IPv6 routing FIB, IPv6 address
    labels, netdev threaded NAPI sysfs files, bonding driver's sysfs files,
    MPLS devconf, IPv4 FIB rules, netns IDs, tcp metrics, TC Qdiscs,
    neighbor entries, ARP entries via ioctl(SIOCGARP), a lot of the link
    information available via rtnetlink.
 
  - Small optimizations from Eric to UDP wake up handling, memory accounting,
    RPS/RFS implementation, TCP packet sizing etc.
 
  - Allow direct page recycling in the bulk API used by XDP, for +2% PPS.
 
  - Support peek with an offset on TCP sockets.
 
  - Add MPTCP APIs for querying last time packets were received/sent/acked,
    and whether MPTCP "upgrade" succeeded on a TCP socket.
 
  - Add intra-node communication shortcut to improve SMC performance.
 
  - Add IPv6 (and IPv{4,6}-over-IPv{4,6}) support to the GTP protocol driver.
 
  - Add HSR-SAN (RedBOX) mode of operation to the HSR protocol driver.
 
  - Add reset reasons for tracing what caused a TCP reset to be sent.
 
  - Introduce direction attribute for xfrm (IPSec) states.
    State can be used either for input or output packet processing.
 
 Things we sprinkled into general kernel code
 --------------------------------------------
 
  - Add bitmap_{read,write}(), bitmap_size(), expose BYTES_TO_BITS().
    This required touch-ups and renaming of a few existing users.
 
  - Add Endian-dependent __counted_by_{le,be} annotations.
 
  - Make building selftests "quieter" by printing summaries like
    "CC object.o" rather than full commands with all the arguments.
 
 Netfilter
 ---------
 
  - Use GFP_KERNEL to clone elements, to deal better with OOM situations
    and avoid failures in the .commit step.
 
 BPF
 ---
 
  - Add eBPF JIT for ARCv2 CPUs.
 
  - Support attaching kprobe BPF programs through kprobe_multi link in
    a session mode, meaning, a BPF program is attached to both function entry
    and return, the entry program can decide if the return program gets
    executed and the entry program can share u64 cookie value with return
    program. "Session mode" is a common use-case for tetragon and bpftrace.
 
  - Add the ability to specify and retrieve BPF cookie for raw tracepoint
    programs in order to ease migration from classic to raw tracepoints.
 
  - Add an internal-only BPF per-CPU instruction for resolving per-CPU
    memory addresses and implement support in x86, ARM64 and RISC-V JITs.
    This allows inlining functions which need to access per-CPU state.
 
  - Optimize x86 BPF JIT's emit_mov_imm64, and add support for various
    atomics in bpf_arena which can be JITed as a single x86 instruction.
    Support BPF arena on ARM64.
 
  - Add a new bpf_wq API for deferring events and refactor process-context
    bpf_timer code to keep common code where possible.
 
  - Harden the BPF verifier's and/or/xor value tracking.
 
  - Introduce crypto kfuncs to let BPF programs call kernel crypto APIs.
 
  - Support bpf_tail_call_static() helper for BPF programs with GCC 13.
 
  - Add bpf_preempt_{disable,enable}() kfuncs in order to allow a BPF
    program to have code sections where preemption is disabled.
 
 Driver API
 ----------
 
  - Skip software TC processing completely if all installed rules are
    marked as HW-only, instead of checking the HW-only flag rule by rule.
 
  - Add support for configuring PoE (Power over Ethernet), similar to
    the already existing support for PoDL (Power over Data Line) config.
 
  - Initial bits of a queue control API, for now allowing a single queue
    to be reset without disturbing packet flow to other queues.
 
  - Common (ethtool) statistics for hardware timestamping.
 
 Tests and tooling
 -----------------
 
  - Remove the need to create a config file to run the net forwarding tests
    so that a naive "make run_tests" can exercise them.
 
  - Define a method of writing tests which require an external endpoint
    to communicate with (to send/receive data towards the test machine).
    Add a few such tests.
 
  - Create a shared code library for writing Python tests. Expose the YAML
    Netlink library from tools/ to the tests for easy Netlink access.
 
  - Move netfilter tests under net/, extend them, separate performance tests
    from correctness tests, and iron out issues found by running them
    "on every commit".
 
  - Refactor BPF selftests to use common network helpers.
 
  - Further work filling in YAML definitions of Netlink messages for:
    nftables, team driver, bonding interfaces, vlan interfaces, VF info,
    TC u32 mark, TC police action.
 
  - Teach Python YAML Netlink to decode attribute policies.
 
  - Extend the definition of the "indexed array" construct in the specs
    to cover arrays of scalars rather than just nests.
 
  - Add hyperlinks between definitions in generated Netlink docs.
 
 Drivers
 -------
 
  - Make sure unsupported flower control flags are rejected by drivers,
    and make more drivers report errors directly to the application rather
    than dmesg (large number of driver changes from Asbjørn Sloth Tønnesen).
 
  - Ethernet high-speed NICs:
    - Broadcom (bnxt):
      - support multiple RSS contexts and steering traffic to them
      - support XDP metadata
      - make page pool allocations more NUMA aware
    - Intel (100G, ice, idpf):
      - extract datapath code common among Intel drivers into a library
      - use fewer resources in switchdev by sharing queues with the PF
      - add PFCP filter support
      - add Ethernet filter support
      - use a spinlock instead of HW lock in PTP clock ops
      - support 5 layer Tx scheduler topology
    - nVidia/Mellanox:
      - 800G link modes and 100G SerDes speeds
      - per-queue IRQ coalescing configuration
    - Marvell Octeon:
      - support offloading TC packet mark action
 
  - Ethernet NICs consumer, embedded and virtual:
    - stop lying about skb->truesize in USB Ethernet drivers, it messes up
      TCP memory calculations
    - Google cloud vNIC:
      - support changing ring size via ethtool
      - support ring reset using the queue control API
    - VirtIO net:
      - expose flow hash from RSS to XDP
      - per-queue statistics
      - add selftests
    - Synopsys (stmmac):
      - support controllers which require an RX clock signal from the MII
        bus to perform their hardware initialization
    - TI:
      - icssg_prueth: support ICSSG-based Ethernet on AM65x SR1.0 devices
      - icssg_prueth: add SW TX / RX Coalescing based on hrtimers
      - cpsw: minimal XDP support
    - Renesas (ravb):
      - support describing the MDIO bus
    - Realtek (r8169):
      - add support for RTL8168M
    - Microchip Sparx5:
      - matchall and flower actions mirred and redirect
 
  - Ethernet switches:
    - nVidia/Mellanox:
      - improve events processing performance
    - Marvell:
      - add support for MV88E6250 family internal PHYs
    - Microchip:
      - add DCB and DSCP mapping support for KSZ switches
      - vsc73xx: convert to PHYLINK
    - Realtek:
      - rtl8226b/rtl8221b: add C45 instances and SerDes switching
 
  - Many driver changes related to PHYLIB and PHYLINK deprecated API cleanup.
 
  - Ethernet PHYs:
    - Add a new driver for Airoha EN8811H 2.5 Gigabit PHY.
    - micrel: lan8814: add support for PPS out and external timestamp trigger
 
  - WiFi:
    - Disable Wireless Extensions (WEXT) in all Wi-Fi 7 devices drivers.
      Modern devices can only be configured using nl80211.
    - mac80211/cfg80211
      - handle color change per link for WiFi 7 Multi-Link Operation
    - Intel (iwlwifi):
      - don't support puncturing in 5 GHz
      - support monitor mode on passive channels
      - BZ-W device support
      - P2P with HE/EHT support
      - re-add support for firmware API 90
      - provide channel survey information for Automatic Channel Selection
    - MediaTek (mt76):
      - mt7921 LED control
      - mt7925 EHT radiotap support
      - mt7920e PCI support
    - Qualcomm (ath11k):
      - P2P support for QCA6390, WCN6855 and QCA2066
      - support hibernation
      - ieee80211-freq-limit Device Tree property support
    - Qualcomm (ath12k):
      - refactoring in preparation of multi-link support
      - suspend and hibernation support
      - ACPI support
      - debugfs support, including dfs_simulate_radar support
    - RealTek:
      - rtw88: RTL8723CS SDIO device support
      - rtw89: RTL8922AE Wi-Fi 7 PCI device support
      - rtw89: complete features of new WiFi 7 chip 8922AE including
        BT-coexistence and Wake-on-WLAN
      - rtw89: use BIOS ACPI settings to set TX power and channels
      - rtl8xxxu: enable Management Frame Protection (MFP) support
 
  - Bluetooth:
    - support for Intel BlazarI and Filmore Peak2 (BE201)
    - support for MediaTek MT7921S SDIO
    - initial support for Intel PCIe BT driver
    - remove HCI_AMP support
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "Core & protocols:

   - Complete rework of garbage collection of AF_UNIX sockets.

     AF_UNIX is prone to forming reference count cycles due to fd
     passing functionality. New method based on Tarjan's Strongly
     Connected Components algorithm should be both faster and remove a
     lot of workarounds we accumulated over the years.

   - Add TCP fraglist GRO support, allowing chaining multiple TCP
     packets and forwarding them together. Useful for small switches /
     routers which lack basic checksum offload in some scenarios (e.g.
     PPPoE).

   - Support using SMP threads for handling packet backlog i.e. packet
     processing from software interfaces and old drivers which don't use
     NAPI. This helps move the processing out of the softirq jumble.

   - Continue work of converting from rtnl lock to RCU protection.

     Don't require rtnl lock when reading: IPv6 routing FIB, IPv6
     address labels, netdev threaded NAPI sysfs files, bonding driver's
     sysfs files, MPLS devconf, IPv4 FIB rules, netns IDs, tcp metrics,
     TC Qdiscs, neighbor entries, ARP entries via ioctl(SIOCGARP), a lot
     of the link information available via rtnetlink.

   - Small optimizations from Eric to UDP wake up handling, memory
     accounting, RPS/RFS implementation, TCP packet sizing etc.

   - Allow direct page recycling in the bulk API used by XDP, for +2%
     PPS.

   - Support peek with an offset on TCP sockets.

   - Add MPTCP APIs for querying last time packets were received/sent/acked
     and whether MPTCP "upgrade" succeeded on a TCP socket.

   - Add intra-node communication shortcut to improve SMC performance.

   - Add IPv6 (and IPv{4,6}-over-IPv{4,6}) support to the GTP protocol
     driver.

   - Add HSR-SAN (RedBOX) mode of operation to the HSR protocol driver.

   - Add reset reasons for tracing what caused a TCP reset to be sent.

   - Introduce direction attribute for xfrm (IPSec) states. State can be
     used either for input or output packet processing.

  Things we sprinkled into general kernel code:

   - Add bitmap_{read,write}(), bitmap_size(), expose BYTES_TO_BITS().

     This required touch-ups and renaming of a few existing users.

   - Add Endian-dependent __counted_by_{le,be} annotations.

   - Make building selftests "quieter" by printing summaries like
     "CC object.o" rather than full commands with all the arguments.

  Netfilter:

   - Use GFP_KERNEL to clone elements, to deal better with OOM
     situations and avoid failures in the .commit step.

  BPF:

   - Add eBPF JIT for ARCv2 CPUs.

   - Support attaching kprobe BPF programs through kprobe_multi link in
     a session mode, meaning, a BPF program is attached to both function
     entry and return, the entry program can decide if the return
     program gets executed and the entry program can share u64 cookie
     value with return program. "Session mode" is a common use-case for
     tetragon and bpftrace.

   - Add the ability to specify and retrieve BPF cookie for raw
     tracepoint programs in order to ease migration from classic to raw
     tracepoints.

   - Add an internal-only BPF per-CPU instruction for resolving per-CPU
     memory addresses and implement support in x86, ARM64 and RISC-V
     JITs. This allows inlining functions which need to access per-CPU
     state.

   - Optimize x86 BPF JIT's emit_mov_imm64, and add support for various
     atomics in bpf_arena which can be JITed as a single x86
     instruction. Support BPF arena on ARM64.

   - Add a new bpf_wq API for deferring events and refactor
     process-context bpf_timer code to keep common code where possible.

   - Harden the BPF verifier's and/or/xor value tracking.

   - Introduce crypto kfuncs to let BPF programs call kernel crypto
     APIs.

   - Support bpf_tail_call_static() helper for BPF programs with GCC 13.

   - Add bpf_preempt_{disable,enable}() kfuncs in order to allow a BPF
     program to have code sections where preemption is disabled.

  Driver API:

   - Skip software TC processing completely if all installed rules are
     marked as HW-only, instead of checking the HW-only flag rule by
     rule.

   - Add support for configuring PoE (Power over Ethernet), similar to
     the already existing support for PoDL (Power over Data Line)
     config.

   - Initial bits of a queue control API, for now allowing a single
     queue to be reset without disturbing packet flow to other queues.

   - Common (ethtool) statistics for hardware timestamping.

  Tests and tooling:

   - Remove the need to create a config file to run the net forwarding
     tests so that a naive "make run_tests" can exercise them.

   - Define a method of writing tests which require an external endpoint
     to communicate with (to send/receive data towards the test
     machine). Add a few such tests.

   - Create a shared code library for writing Python tests. Expose the
     YAML Netlink library from tools/ to the tests for easy Netlink
     access.

   - Move netfilter tests under net/, extend them, separate performance
     tests from correctness tests, and iron out issues found by running
     them "on every commit".

   - Refactor BPF selftests to use common network helpers.

   - Further work filling in YAML definitions of Netlink messages for:
     nftables, team driver, bonding interfaces, vlan interfaces, VF
     info, TC u32 mark, TC police action.

   - Teach Python YAML Netlink to decode attribute policies.

   - Extend the definition of the "indexed array" construct in the specs
     to cover arrays of scalars rather than just nests.

   - Add hyperlinks between definitions in generated Netlink docs.

  Drivers:

   - Make sure unsupported flower control flags are rejected by drivers,
     and make more drivers report errors directly to the application
     rather than dmesg (large number of driver changes from Asbjørn
     Sloth Tønnesen).

   - Ethernet high-speed NICs:
      - Broadcom (bnxt):
         - support multiple RSS contexts and steering traffic to them
         - support XDP metadata
         - make page pool allocations more NUMA aware
      - Intel (100G, ice, idpf):
         - extract datapath code common among Intel drivers into a library
         - use fewer resources in switchdev by sharing queues with the PF
         - add PFCP filter support
         - add Ethernet filter support
         - use a spinlock instead of HW lock in PTP clock ops
         - support 5 layer Tx scheduler topology
      - nVidia/Mellanox:
         - 800G link modes and 100G SerDes speeds
         - per-queue IRQ coalescing configuration
      - Marvell Octeon:
         - support offloading TC packet mark action

   - Ethernet NICs consumer, embedded and virtual:
      - stop lying about skb->truesize in USB Ethernet drivers, it
        messes up TCP memory calculations
      - Google cloud vNIC:
         - support changing ring size via ethtool
         - support ring reset using the queue control API
      - VirtIO net:
         - expose flow hash from RSS to XDP
         - per-queue statistics
         - add selftests
      - Synopsys (stmmac):
         - support controllers which require an RX clock signal from the
           MII bus to perform their hardware initialization
      - TI:
         - icssg_prueth: support ICSSG-based Ethernet on AM65x SR1.0 devices
         - icssg_prueth: add SW TX / RX Coalescing based on hrtimers
         - cpsw: minimal XDP support
      - Renesas (ravb):
         - support describing the MDIO bus
      - Realtek (r8169):
         - add support for RTL8168M
      - Microchip Sparx5:
         - matchall and flower actions mirred and redirect

   - Ethernet switches:
      - nVidia/Mellanox:
         - improve events processing performance
      - Marvell:
         - add support for MV88E6250 family internal PHYs
      - Microchip:
         - add DCB and DSCP mapping support for KSZ switches
         - vsc73xx: convert to PHYLINK
      - Realtek:
         - rtl8226b/rtl8221b: add C45 instances and SerDes switching

   - Many driver changes related to PHYLIB and PHYLINK deprecated API
     cleanup

   - Ethernet PHYs:
      - Add a new driver for Airoha EN8811H 2.5 Gigabit PHY.
      - micrel: lan8814: add support for PPS out and external timestamp trigger

   - WiFi:
      - Disable Wireless Extensions (WEXT) in all Wi-Fi 7 devices
        drivers. Modern devices can only be configured using nl80211.
      - mac80211/cfg80211
         - handle color change per link for WiFi 7 Multi-Link Operation
      - Intel (iwlwifi):
         - don't support puncturing in 5 GHz
         - support monitor mode on passive channels
         - BZ-W device support
         - P2P with HE/EHT support
         - re-add support for firmware API 90
         - provide channel survey information for Automatic Channel Selection
      - MediaTek (mt76):
         - mt7921 LED control
         - mt7925 EHT radiotap support
         - mt7920e PCI support
      - Qualcomm (ath11k):
         - P2P support for QCA6390, WCN6855 and QCA2066
         - support hibernation
         - ieee80211-freq-limit Device Tree property support
      - Qualcomm (ath12k):
         - refactoring in preparation of multi-link support
         - suspend and hibernation support
         - ACPI support
         - debugfs support, including dfs_simulate_radar support
      - RealTek:
         - rtw88: RTL8723CS SDIO device support
         - rtw89: RTL8922AE Wi-Fi 7 PCI device support
         - rtw89: complete features of new WiFi 7 chip 8922AE including
           BT-coexistence and Wake-on-WLAN
         - rtw89: use BIOS ACPI settings to set TX power and channels
         - rtl8xxxu: enable Management Frame Protection (MFP) support

   - Bluetooth:
      - support for Intel BlazarI and Filmore Peak2 (BE201)
      - support for MediaTek MT7921S SDIO
      - initial support for Intel PCIe BT driver
      - remove HCI_AMP support"

* tag 'net-next-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1827 commits)
  selftests: netfilter: fix packetdrill conntrack testcase
  net: gro: fix napi_gro_cb zeroed alignment
  Bluetooth: btintel_pcie: Refactor and code cleanup
  Bluetooth: btintel_pcie: Fix warning reported by sparse
  Bluetooth: hci_core: Fix not handling hdev->le_num_of_adv_sets=1
  Bluetooth: btintel: Fix compiler warning for multi_v7_defconfig config
  Bluetooth: btintel_pcie: Fix compiler warnings
  Bluetooth: btintel_pcie: Add *setup* function to download firmware
  Bluetooth: btintel_pcie: Add support for PCIe transport
  Bluetooth: btintel: Export few static functions
  Bluetooth: HCI: Remove HCI_AMP support
  Bluetooth: L2CAP: Fix div-by-zero in l2cap_le_flowctl_init()
  Bluetooth: qca: Fix error code in qca_read_fw_build_info()
  Bluetooth: hci_conn: Use __counted_by() and avoid -Wfamnae warning
  Bluetooth: btintel: Add support for Filmore Peak2 (BE201)
  Bluetooth: btintel: Add support for BlazarI
  LE Create Connection command timeout increased to 20 secs
  dt-bindings: net: bluetooth: Add MediaTek MT7921S SDIO Bluetooth
  Bluetooth: compute LE flow credits based on recvbuf space
  Bluetooth: hci_sync: Use cmd->num_cis instead of magic number
  ...
 2024-05-14 19:42:24 -07:00
Zheng Yejian
e60b613df8 ftrace: Fix possible use-after-free issue in ftrace_location() 
KASAN reports a bug:

  BUG: KASAN: use-after-free in ftrace_location+0x90/0x120
  Read of size 8 at addr ffff888141d40010 by task insmod/424
  CPU: 8 PID: 424 Comm: insmod Tainted: G        W          6.9.0-rc2+
  [...]
  Call Trace:
   <TASK>
   dump_stack_lvl+0x68/0xa0
   print_report+0xcf/0x610
   kasan_report+0xb5/0xe0
   ftrace_location+0x90/0x120
   register_kprobe+0x14b/0xa40
   kprobe_init+0x2d/0xff0 [kprobe_example]
   do_one_initcall+0x8f/0x2d0
   do_init_module+0x13a/0x3c0
   load_module+0x3082/0x33d0
   init_module_from_file+0xd2/0x130
   __x64_sys_finit_module+0x306/0x440
   do_syscall_64+0x68/0x140
   entry_SYSCALL_64_after_hwframe+0x71/0x79

The root cause is that, in lookup_rec(), ftrace record of some address
is being searched in ftrace pages of some module, but those ftrace pages
at the same time is being freed in ftrace_release_mod() as the
corresponding module is being deleted:

           CPU1                       |      CPU2
  register_kprobes() {                | delete_module() {
    check_kprobe_address_safe() {     |
      arch_check_ftrace_location() {  |
        ftrace_location() {           |
          lookup_rec() // USE!        |   ftrace_release_mod() // Free!

To fix this issue:
  1. Hold rcu lock as accessing ftrace pages in ftrace_location_range();
  2. Use ftrace_location_range() instead of lookup_rec() in
     ftrace_location();
  3. Call synchronize_rcu() before freeing any ftrace pages both in
     ftrace_process_locs()/ftrace_release_mod()/ftrace_free_mem().

Link: https://lore.kernel.org/linux-trace-kernel/20240509192859.1273558-1-zhengyejian1@huawei.com

Cc: stable@vger.kernel.org
Cc: <mhiramat@kernel.org>
Cc: <mark.rutland@arm.com>
Cc: <mathieu.desnoyers@efficios.com>
Fixes: ae6aa16fdc ("kprobes: introduce ftrace based optimization")
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-05-14 11:13:27 -04:00
Mike Rapoport (IBM)
7582b7be16 kprobes: remove dependency on CONFIG_MODULES 
kprobes depended on CONFIG_MODULES because it has to allocate memory for
code.

Since code allocations are now implemented with execmem, kprobes can be
enabled in non-modular kernels.

Add #ifdef CONFIG_MODULE guards for the code dealing with kprobes inside
modules, make CONFIG_KPROBES select CONFIG_EXECMEM and drop the
dependency of CONFIG_KPROBES on CONFIG_MODULES.

Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
[mcgrof: rebase in light of NEED_TASKS_RCU ]
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
 2024-05-14 00:35:06 -07:00
Dr. David Alan Gilbert
d2cc859cc8 ftrace: Remove unused global 'ftrace_direct_func_count' 
Commit 8788ca164e ("ftrace: Remove the legacy _ftrace_direct API")
stopped setting the 'ftrace_direct_func_count' variable, but left
it around.  Clean it up.

Link: https://lore.kernel.org/linux-trace-kernel/20240506233305.215735-1-linux@treblig.org

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-05-14 02:09:40 -04:00
Dr. David Alan Gilbert
c9d5b7b826 ftrace: Remove unused list 'ftrace_direct_funcs' 
Commit 8788ca164e ("ftrace: Remove the legacy _ftrace_direct API")
stopped using 'ftrace_direct_funcs' (and the associated
struct ftrace_direct_func).  Remove them.

Build tested only (on x86-64 with FTRACE and DYNAMIC_FTRACE
enabled)

Link: https://lore.kernel.org/linux-trace-kernel/20240504132303.67538-1-linux@treblig.org

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-05-14 02:09:00 -04:00
Thorsten Blum
347bd7f072 tracing: Improve benchmark test performance by using do_div() 
Partially revert commit d6cb38e108 ("tracing: Use div64_u64() instead
of do_div()") and use do_div() again to utilize its faster 64-by-32
division compared to the 64-by-64 division done by div64_u64().

Explicitly cast the divisor bm_cnt to u32 to prevent a Coccinelle
warning reported by do_div.cocci. The warning was removed with commit
d6cb38e108 ("tracing: Use div64_u64() instead of do_div()").

Using the faster 64-by-32 division and casting bm_cnt to u32 is safe
because we return early from trace_do_benchmark() if bm_cnt > UINT_MAX.
This approach is already used twice in trace_do_benchmark() when
calculating the standard deviation:

	do_div(stddev, (u32)bm_cnt);
	do_div(stddev, (u32)bm_cnt - 1);

Link: https://lore.kernel.org/linux-trace-kernel/20240329160229.4874-2-thorsten.blum@toblux.com

Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-05-13 20:00:57 -04:00
Steven Rostedt (Google)
fe832be05a ring-buffer: Have mmapped ring buffer keep track of missed events 
While testing libtracefs on the mmapped ring buffer, the test that checks
if missed events are accounted for failed when using the mapped buffer.
This is because the mapped page does not update the missed events that
were dropped because the writer filled up the ring buffer before the
reader could catch it.

Add the missed events to the reader page/sub-buffer when the IOCTL is done
and a new reader page is acquired.

Note that all accesses to the reader_page via rb_page_commit() had to be
switched to rb_page_size(), and rb_page_size() which was just a copy of
rb_page_commit() but now it masks out the RB_MISSED bits. This is needed
as the mapped reader page is still active in the ring buffer code and
where it reads the commit field of the bpage for the size, it now must
mask it otherwise the missed bits that are now set will corrupt the size
returned.

Link: https://lore.kernel.org/linux-trace-kernel/20240312175405.12fb6726@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-05-13 19:55:22 -04:00
Jakub Kicinski
6e62702feb bpf-next-for-netdev 
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-05-13

We've added 119 non-merge commits during the last 14 day(s) which contain
a total of 134 files changed, 9462 insertions(+), 4742 deletions(-).

The main changes are:

1) Add BPF JIT support for 32-bit ARCv2 processors, from Shahab Vahedi.

2) Add BPF range computation improvements to the verifier in particular
   around XOR and OR operators, refactoring of checks for range computation
   and relaxing MUL range computation so that src_reg can also be an unknown
   scalar, from Cupertino Miranda.

3) Add support to attach kprobe BPF programs through kprobe_multi link in
   a session mode, meaning, a BPF program is attached to both function entry
   and return, the entry program can decide if the return program gets
   executed and the entry program can share u64 cookie value with return
   program. Session mode is a common use-case for tetragon and bpftrace,
   from Jiri Olsa.

4) Fix a potential overflow in libbpf's ring__consume_n() and improve libbpf
   as well as BPF selftest's struct_ops handling, from Andrii Nakryiko.

5) Improvements to BPF selftests in context of BPF gcc backend,
   from Jose E. Marchesi & David Faust.

6) Migrate remaining BPF selftest tests from test_sock_addr.c to prog_test-
   -style in order to retire the old test, run it in BPF CI and additionally
   expand test coverage, from Jordan Rife.

7) Big batch for BPF selftest refactoring in order to remove duplicate code
   around common network helpers, from Geliang Tang.

8) Another batch of improvements to BPF selftests to retire obsolete
   bpf_tcp_helpers.h as everything is available vmlinux.h,
   from Martin KaFai Lau.

9) Fix BPF map tear-down to not walk the map twice on free when both timer
   and wq is used, from Benjamin Tissoires.

10) Fix BPF verifier assumptions about socket->sk that it can be non-NULL,
    from Alexei Starovoitov.

11) Change BTF build scripts to using --btf_features for pahole v1.26+,
    from Alan Maguire.

12) Small improvements to BPF reusing struct_size() and krealloc_array(),
    from Andy Shevchenko.

13) Fix s390 JIT to emit a barrier for BPF_FETCH instructions,
    from Ilya Leoshkevich.

14) Extend TCP ->cong_control() callback in order to feed in ack and
    flag parameters and allow write-access to tp->snd_cwnd_stamp
    from BPF program, from Miao Xu.

15) Add support for internal-only per-CPU instructions to inline
    bpf_get_smp_processor_id() helper call for arm64 and riscv64 BPF JITs,
    from Puranjay Mohan.

16) Follow-up to remove the redundant ethtool.h from tooling infrastructure,
    from Tushar Vyavahare.

17) Extend libbpf to support "module:<function>" syntax for tracing
    programs, from Viktor Malik.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (119 commits)
  bpf: make list_for_each_entry portable
  bpf: ignore expected GCC warning in test_global_func10.c
  bpf: disable strict aliasing in test_global_func9.c
  selftests/bpf: Free strdup memory in xdp_hw_metadata
  selftests/bpf: Fix a few tests for GCC related warnings.
  bpf: avoid gcc overflow warning in test_xdp_vlan.c
  tools: remove redundant ethtool.h from tooling infra
  selftests/bpf: Expand ATTACH_REJECT tests
  selftests/bpf: Expand getsockname and getpeername tests
  sefltests/bpf: Expand sockaddr hook deny tests
  selftests/bpf: Expand sockaddr program return value tests
  selftests/bpf: Retire test_sock_addr.(c|sh)
  selftests/bpf: Remove redundant sendmsg test cases
  selftests/bpf: Migrate ATTACH_REJECT test cases
  selftests/bpf: Migrate expected_attach_type tests
  selftests/bpf: Migrate wildcard destination rewrite test
  selftests/bpf: Migrate sendmsg6 v4 mapped address tests
  selftests/bpf: Migrate sendmsg deny test cases
  selftests/bpf: Migrate WILDCARD_IP test
  selftests/bpf: Handle SYSCALL_EPERM and SYSCALL_ENOTSUPP test cases
  ...
====================

Link: https://lore.kernel.org/r/20240513134114.17575-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2024-05-13 16:41:10 -07:00
Paul E. McKenney
33f137143e ftrace: Use asynchronous grace period for register_ftrace_direct() 
When running heavy test workloads with KASAN enabled, RCU Tasks grace
periods can extend for many tens of seconds, significantly slowing
trace registration.  Therefore, make the registration-side RCU Tasks
grace period be asynchronous via call_rcu_tasks().

Link: https://lore.kernel.org/linux-trace-kernel/ac05be77-2972-475b-9b57-56bef15aa00a@paulmck-laptop

Reported-by: Jakub Kicinski <kuba@kernel.org>
Reported-by: Alexei Starovoitov <ast@kernel.org>
Reported-by: Chris Mason <clm@fb.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-05-13 19:36:40 -04:00
Yuran Pereira
c5963a0990 ftrace: Replaces simple_strtoul in ftrace 
The function simple_strtoul performs no error checking in scenarios
where the input value overflows the intended output variable.
This results in this function successfully returning, even when the
output does not match the input string (aka the function returns
successfully even when the result is wrong).

Or as it was mentioned [1], "...simple_strtol(), simple_strtoll(),
simple_strtoul(), and simple_strtoull() functions explicitly ignore
overflows, which may lead to unexpected results in callers."
Hence, the use of those functions is discouraged.

This patch replaces all uses of the simple_strtoul with the safer
alternatives kstrtoul and kstruint.

Callers affected:
- add_rec_by_index
- set_graph_max_depth_function

Side effects of this patch:
- Since `fgraph_max_depth` is an `unsigned int`, this patch uses
  kstrtouint instead of kstrtoul to avoid any compiler warnings
  that could originate from calling the latter.
- This patch ensures that the callers of kstrtou* return accordingly
  when kstrtoul and kstruint fail for some reason.
  In this case, both callers this patch is addressing return 0 on error.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#simple-strtol-simple-strtoll-simple-strtoul-simple-strtoull

Link: https://lore.kernel.org/linux-trace-kernel/GV1PR10MB656333529A8D7B8AFB28D238E8B4A@GV1PR10MB6563.EURPRD10.PROD.OUTLOOK.COM

Signed-off-by: Yuran Pereira <yuran.pereira@hotmail.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-05-13 19:36:40 -04:00
Vincent Donnefort
cf9f0f7c4c tracing: Allow user-space mapping of the ring-buffer 
Currently, user-space extracts data from the ring-buffer via splice,
which is handy for storage or network sharing. However, due to splice
limitations, it is imposible to do real-time analysis without a copy.

A solution for that problem is to let the user-space map the ring-buffer
directly.

The mapping is exposed via the per-CPU file trace_pipe_raw. The first
element of the mapping is the meta-page. It is followed by each
subbuffer constituting the ring-buffer, ordered by their unique page ID:

  * Meta-page -- include/uapi/linux/trace_mmap.h for a description
  * Subbuf ID 0
  * Subbuf ID 1
     ...

It is therefore easy to translate a subbuf ID into an offset in the
mapping:

  reader_id = meta->reader->id;
  reader_offset = meta->meta_page_size + reader_id * meta->subbuf_size;

When new data is available, the mapper must call a newly introduced ioctl:
TRACE_MMAP_IOCTL_GET_READER. This will update the Meta-page reader ID to
point to the next reader containing unread data.

Mapping will prevent snapshot and buffer size modifications.

Link: https://lore.kernel.org/linux-trace-kernel/20240510140435.3550353-4-vdonnefort@google.com

CC: <linux-mm@kvack.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-05-13 18:09:56 -04:00
Vincent Donnefort
117c39200d ring-buffer: Introducing ring-buffer mapping functions 
In preparation for allowing the user-space to map a ring-buffer, add
a set of mapping functions:

  ring_buffer_{map,unmap}()

And controls on the ring-buffer:

  ring_buffer_map_get_reader()  /* swap reader and head */

Mapping the ring-buffer also involves:

  A unique ID for each subbuf of the ring-buffer, currently they are
  only identified through their in-kernel VA.

  A meta-page, where are stored ring-buffer statistics and a
  description for the current reader

The linear mapping exposes the meta-page, and each subbuf of the
ring-buffer, ordered following their unique ID, assigned during the
first mapping.

Once mapped, no subbuf can get in or out of the ring-buffer: the buffer
size will remain unmodified and the splice enabling functions will in
reality simply memcpy the data instead of swapping subbufs.

Link: https://lore.kernel.org/linux-trace-kernel/20240510140435.3550353-3-vdonnefort@google.com

CC: <linux-mm@kvack.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-05-13 18:09:56 -04:00
Vincent Donnefort
c09d4167b5 ring-buffer: Allocate sub-buffers with __GFP_COMP 
In preparation for the ring-buffer memory mapping, allocate compound
pages for the ring-buffer sub-buffers to enable us to map them to
user-space with vm_insert_pages().

Link: https://lore.kernel.org/linux-trace-kernel/20240510140435.3550353-2-vdonnefort@google.com

Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-05-13 18:09:55 -04:00
Linus Torvalds
c0b9620bc3 RCU pull request for v6.10 
This pull request contains the following branches:
 
 fixes.2024.04.15a: Fix a lockdep complain for lazy-preemptible kernel,
 remove redundant BH disable for TINY_RCU, remove redundant READ_ONCE()
 in tree.c, fix false positives KCSAN splat and fix buffer overflow in
 the print_cpu_stall_info().
 
 misc.2024.04.12a: Misc updates related to bpf, tracing and update the
 MAINTAINERS file.
 
 rcu-sync-normal-improve.2024.04.15a: An improvement of a normal
 synchronize_rcu() call in terms of latency. It maintains a separate
 track for sync. users only. This approach bypasses per-cpu nocb-lists
 thus sync-users do not depend on nocb-list length and how fast regular
 callbacks are processed.
 
 rcu-tasks.2024.04.15a: RCU tasks, switch tasks RCU grace periods to
 sleep at TASK_IDLE priority, fix some comments, add some diagnostic
 warning to the exit_tasks_rcu_start() and fix a buffer overflow in
 the show_rcu_tasks_trace_gp_kthread().
 
 rcutorture.2024.04.15a: Increase memory to guest OS, fix a Tasks
 Rude RCU testing, some updates for TREE09, dump mode information
 to debug GP kthread state, remove redundant READ_ONCE(), fix some
 comments about RCU_TORTURE_PIPE_LEN and pipe_count, remove some
 redundant pointer initialization, fix a hung splat task by when
 the rcutorture tests start to exit, fix invalid context warning,
 add '--do-kvfree' parameter to torture test and use slow register
 unregister callbacks only for rcutype test.
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Merge tag 'rcu.next.v6.10' of https://github.com/urezki/linux

Pull RCU updates from Uladzislau Rezki:

 - Fix a lockdep complain for lazy-preemptible kernel, remove redundant
   BH disable for TINY_RCU, remove redundant READ_ONCE() in tree.c, fix
   false positives KCSAN splat and fix buffer overflow in the
   print_cpu_stall_info().

 - Misc updates related to bpf, tracing and update the MAINTAINERS file.

 - An improvement of a normal synchronize_rcu() call in terms of
   latency. It maintains a separate track for sync. users only. This
   approach bypasses per-cpu nocb-lists thus sync-users do not depend on
   nocb-list length and how fast regular callbacks are processed.

 - RCU tasks: switch tasks RCU grace periods to sleep at TASK_IDLE
   priority, fix some comments, add some diagnostic warning to the
   exit_tasks_rcu_start() and fix a buffer overflow in the
   show_rcu_tasks_trace_gp_kthread().

 - RCU torture: Increase memory to guest OS, fix a Tasks Rude RCU
   testing, some updates for TREE09, dump mode information to debug GP
   kthread state, remove redundant READ_ONCE(), fix some comments about
   RCU_TORTURE_PIPE_LEN and pipe_count, remove some redundant pointer
   initialization, fix a hung splat task by when the rcutorture tests
   start to exit, fix invalid context warning, add '--do-kvfree'
   parameter to torture test and use slow register unregister callbacks
   only for rcutype test.

* tag 'rcu.next.v6.10' of https://github.com/urezki/linux: (48 commits)
  rcutorture: Use rcu_gp_slow_register/unregister() only for rcutype test
  torture: Scale --do-kvfree test time
  rcutorture: Fix invalid context warning when enable srcu barrier testing
  rcutorture: Make stall-tasks directly exit when rcutorture tests end
  rcutorture: Removing redundant function pointer initialization
  rcutorture: Make rcutorture support print rcu-tasks gp state
  rcutorture: Use the gp_kthread_dbg operation specified by cur_ops
  rcutorture: Re-use value stored to ->rtort_pipe_count instead of re-reading
  rcutorture: Fix rcu_torture_one_read() pipe_count overflow comment
  rcutorture: Remove extraneous rcu_torture_pipe_update_one() READ_ONCE()
  rcu: Allocate WQ with WQ_MEM_RECLAIM bit set
  rcu: Support direct wake-up of synchronize_rcu() users
  rcu: Add a trace event for synchronize_rcu_normal()
  rcu: Reduce synchronize_rcu() latency
  rcu: Fix buffer overflow in print_cpu_stall_info()
  rcu: Mollify sparse with RCU guard
  rcu-tasks: Fix show_rcu_tasks_trace_gp_kthread buffer overflow
  rcu-tasks: Fix the comments for tasks_rcu_exit_srcu_stall_timer
  rcu-tasks: Replace exit_tasks_rcu_start() initialization with WARN_ON_ONCE()
  rcu: Remove redundant CONFIG_PROVE_RCU #if condition
  ...
 2024-05-13 09:49:06 -07:00
Beau Belgrave
bd125a0840 tracing/user_events: Fix non-spaced field matching 
When the ABI was updated to prevent same name w/different args, it
missed an important corner case when fields don't end with a space.
Typically, space is used for fields to help separate them, like
"u8 field1; u8 field2". If no spaces are used, like
"u8 field1;u8 field2", then the parsing works for the first time.
However, the match check fails on a subsequent register, leading to
confusion.

This is because the match check uses argv_split() and assumes that all
fields will be split upon the space. When spaces are used, we get back
{ "u8", "field1;" }, without spaces we get back { "u8", "field1;u8" }.
This causes a mismatch, and the user program gets back -EADDRINUSE.

Add a method to detect this case before calling argv_split(). If found
force a space after the field separator character ';'. This ensures all
cases work properly for matching.

With this fix, the following are all treated as matching:
u8 field1;u8 field2
u8 field1; u8 field2
u8 field1;\tu8 field2
u8 field1;\nu8 field2

Link: https://lore.kernel.org/linux-trace-kernel/20240423162338.292-2-beaub@linux.microsoft.com

Fixes: ba470eebc2 ("tracing/user_events: Prevent same name but different args event")
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-05-13 12:15:45 -04:00
Jakub Kicinski
e7073830cc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 
Cross-merge networking fixes after downstream PR.

No conflicts.

Adjacent changes:

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
  35d92abfba ("net: hns3: fix kernel crash when devlink reload during initialization")
  2a1a1a7b5f ("net: hns3: add command queue trace for hns3")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2024-05-09 10:01:01 -07:00
Linus Torvalds
2c17a1cd90 Probes fixes for v6.9-rc6: 
- probe-events: Fix memory leak in parsing probe argument. There is a
   memory leak (forget to free an allocated buffer) in a memory allocation
   failure path. Fixes it to jump to the correct error handling code.
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Merge tag 'probes-fixes-v6.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes fix from Masami Hiramatsu:

 - probe-events: Fix memory leak in parsing probe argument.

   There is a memory leak (forget to free an allocated buffer) in a
   memory allocation failure path. Fix it to jump to the correct error
   handling code.

* tag 'probes-fixes-v6.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/probes: Fix memory leak in traceprobe_parse_probe_arg_body()
 2024-05-05 09:56:50 -07:00
Steven Rostedt (Google)
b63db58e2f eventfs/tracing: Add callback for release of an eventfs_inode 
Synthetic events create and destroy tracefs files when they are created
and removed. The tracing subsystem has its own file descriptor
representing the state of the events attached to the tracefs files.
There's a race between the eventfs files and this file descriptor of the
tracing system where the following can cause an issue:

With two scripts 'A' and 'B' doing:

  Script 'A':
    echo "hello int aaa" > /sys/kernel/tracing/synthetic_events
    while :
    do
      echo 0 > /sys/kernel/tracing/events/synthetic/hello/enable
    done

  Script 'B':
    echo > /sys/kernel/tracing/synthetic_events

Script 'A' creates a synthetic event "hello" and then just writes zero
into its enable file.

Script 'B' removes all synthetic events (including the newly created
"hello" event).

What happens is that the opening of the "enable" file has:

 {
	struct trace_event_file *file = inode->i_private;
	int ret;

	ret = tracing_check_open_get_tr(file->tr);
 [..]

But deleting the events frees the "file" descriptor, and a "use after
free" happens with the dereference at "file->tr".

The file descriptor does have a reference counter, but there needs to be a
way to decrement it from the eventfs when the eventfs_inode is removed
that represents this file descriptor.

Add an optional "release" callback to the eventfs_entry array structure,
that gets called when the eventfs file is about to be removed. This allows
for the creating on the eventfs file to increment the tracing file
descriptor ref counter. When the eventfs file is deleted, it can call the
release function that will call the put function for the tracing file
descriptor.

This will protect the tracing file from being freed while a eventfs file
that references it is being opened.

Link: https://lore.kernel.org/linux-trace-kernel/20240426073410.17154-1-Tze-nan.Wu@mediatek.com/
Link: https://lore.kernel.org/linux-trace-kernel/20240502090315.448cba46@gandalf.local.home

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 5790b1fb3d ("eventfs: Remove eventfs_file and just use eventfs_inode")
Reported-by: Tze-nan wu <Tze-nan.Wu@mediatek.com>
Tested-by: Tze-nan Wu (吳澤南) <Tze-nan.Wu@mediatek.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-05-04 04:25:37 -04:00
Andrii Nakryiko
e03c05ac98 rethook: honor CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING in rethook_try_get() 
Take into account CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING when validating
that RCU is watching when trying to setup rethooko on a function entry.

One notable exception when we force rcu_is_watching() check is
CONFIG_KPROBE_EVENTS_ON_NOTRACE=y case, in which case kretprobes will use
old-style int3-based workflow instead of relying on ftrace, making RCU
watching check important to validate.

This further (in addition to improvements in the previous patch)
improves BPF multi-kretprobe (which rely on rethook) runtime throughput
by 2.3%, according to BPF benchmarks ([0]).

  [0] https://lore.kernel.org/bpf/CAEf4BzauQ2WKMjZdc9s0rBWa01BYbgwHN6aNDXQSHYia47pQ-w@mail.gmail.com/

Link: https://lore.kernel.org/all/20240418190909.704286-2-andrii@kernel.org/

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-05-01 23:18:48 +09:00
Andrii Nakryiko
b0e28a4b5b ftrace: make extra rcu_is_watching() validation check optional 
Introduce CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING config option to
control whether ftrace low-level code performs additional
rcu_is_watching()-based validation logic in an attempt to catch noinstr
violations.

This check is expected to never be true and is mostly useful for
low-level validation of ftrace subsystem invariants. For most users it
should probably be kept disabled to eliminate unnecessary runtime
overhead.

This improves BPF multi-kretprobe (relying on ftrace and rethook
infrastructure) runtime throughput by 2%, according to BPF benchmarks ([0]).

  [0] https://lore.kernel.org/bpf/CAEf4BzauQ2WKMjZdc9s0rBWa01BYbgwHN6aNDXQSHYia47pQ-w@mail.gmail.com/

Link: https://lore.kernel.org/all/20240418190909.704286-1-andrii@kernel.org/

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-05-01 23:18:48 +09:00
Kui-Feng Lee
5120d167e2 rethook: Remove warning messages printed for finding return address of a frame. 
The function rethook_find_ret_addr() prints a warning message and returns 0
when the target task is running and is not the "current" task in order to
prevent the incorrect return address, although it still may return an
incorrect address.

However, the warning message turns into noise when BPF profiling programs
call bpf_get_task_stack() on running tasks in a firm with a large number of
hosts.

The callers should be aware and willing to take the risk of receiving an
incorrect return address from a task that is currently running other than
the "current" one. A warning is not needed here as the callers are intent
on it.

Link: https://lore.kernel.org/all/20240408175140.60223-1-thinker.li@gmail.com/

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-05-01 23:18:47 +09:00
Ye Bin
20fe4d07bd tracing/probes: support '%pD' type for print struct file's name 
As like '%pd' type, this patch supports print type '%pD' for print file's
name. For example "name=$arg1:%pD" casts the `$arg1` as (struct file*),
dereferences the "file.f_path.dentry.d_name.name" field and stores it to
"name" argument as a kernel string.
Here is an example:
[tracing]# echo 'p:testprobe vfs_read name=$arg1:%pD' > kprobe_event
[tracing]# echo 1 > events/kprobes/testprobe/enable
[tracing]# grep -q "1" events/kprobes/testprobe/enable
[tracing]# echo 0 > events/kprobes/testprobe/enable
[tracing]# grep "vfs_read" trace | grep "enable"
            grep-15108   [003] .....  5228.328609: testprobe: (vfs_read+0x4/0xbb0) name="enable"

Note that this expects the given argument (e.g. $arg1) is an address of struct
file. User must ensure it.

Link: https://lore.kernel.org/all/20240322064308.284457-3-yebin10@huawei.com/
[Masami: replaced "previous patch" with '%pd' type]

Signed-off-by: Ye Bin <yebin10@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-05-01 23:18:47 +09:00
Ye Bin
d9b15224dd tracing/probes: support '%pd' type for print struct dentry's name 
During fault locating, the file name needs to be printed based on the
dentry  address. The offset needs to be calculated each time, which
is troublesome. Similar to printk, kprobe support print type '%pd' for
print dentry's name. For example "name=$arg1:%pd" casts the `$arg1`
as (struct dentry *), dereferences the "d_name.name" field and stores
it to "name" argument as a kernel string.
Here is an example:
[tracing]# echo 'p:testprobe dput name=$arg1:%pd' > kprobe_events
[tracing]# echo 1 > events/kprobes/testprobe/enable
[tracing]# grep -q "1" events/kprobes/testprobe/enable
[tracing]# echo 0 > events/kprobes/testprobe/enable
[tracing]# cat trace | grep "enable"
	    bash-14844   [002] ..... 16912.889543: testprobe: (dput+0x4/0x30) name="enable"
            grep-15389   [003] ..... 16922.834182: testprobe: (dput+0x4/0x30) name="enable"
            grep-15389   [003] ..... 16922.836103: testprobe: (dput+0x4/0x30) name="enable"
            bash-14844   [001] ..... 16931.820909: testprobe: (dput+0x4/0x30) name="enable"

Note that this expects the given argument (e.g. $arg1) is an address of struct
dentry. User must ensure it.

Link: https://lore.kernel.org/all/20240322064308.284457-2-yebin10@huawei.com/

Signed-off-by: Ye Bin <yebin10@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-05-01 23:18:47 +09:00
Andrii Nakryiko
cdf355cc60 uprobes: add speculative lockless system-wide uprobe filter check 
It's very common with BPF-based uprobe/uretprobe use cases to have
a system-wide (not PID specific) probes used. In this case uprobe's
trace_uprobe_filter->nr_systemwide counter is bumped at registration
time, and actual filtering is short circuited at the time when
uprobe/uretprobe is triggered.

This is a great optimization, and the only issue with it is that to even
get to checking this counter uprobe subsystem is taking
read-side trace_uprobe_filter->rwlock. This is actually noticeable in
profiles and is just another point of contention when uprobe is
triggered on multiple CPUs simultaneously.

This patch moves this nr_systemwide check outside of filter list's
rwlock scope, as rwlock is meant to protect list modification, while
nr_systemwide-based check is speculative and racy already, despite the
lock (as discussed in [0]). trace_uprobe_filter_remove() and
trace_uprobe_filter_add() already check for filter->nr_systewide
explicitly outside of __uprobe_perf_filter, so no modifications are
required there.

Confirming with BPF selftests's based benchmarks.

BEFORE (based on changes in previous patch)
===========================================
uprobe-nop     :    2.732 ± 0.022M/s
uprobe-push    :    2.621 ± 0.016M/s
uprobe-ret     :    1.105 ± 0.007M/s
uretprobe-nop  :    1.396 ± 0.007M/s
uretprobe-push :    1.347 ± 0.008M/s
uretprobe-ret  :    0.800 ± 0.006M/s

AFTER
=====
uprobe-nop     :    2.878 ± 0.017M/s (+5.5%, total +8.3%)
uprobe-push    :    2.753 ± 0.013M/s (+5.3%, total +10.2%)
uprobe-ret     :    1.142 ± 0.010M/s (+3.8%, total +3.8%)
uretprobe-nop  :    1.444 ± 0.008M/s (+3.5%, total +6.5%)
uretprobe-push :    1.410 ± 0.010M/s (+4.8%, total +7.1%)
uretprobe-ret  :    0.816 ± 0.002M/s (+2.0%, total +3.9%)

In the above, first percentage value is based on top of previous patch
(lazy uprobe buffer optimization), while the "total" percentage is
based on kernel without any of the changes in this patch set.

As can be seen, we get about 4% - 10% speed up, in total, with both lazy
uprobe buffer and speculative filter check optimizations.

  [0] https://lore.kernel.org/bpf/20240313131926.GA19986@redhat.com/

Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/all/20240318181728.2795838-4-andrii@kernel.org/

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-05-01 23:18:46 +09:00
Andrii Nakryiko
1b8f85defb uprobes: prepare uprobe args buffer lazily 
uprobe_cpu_buffer and corresponding logic to store uprobe args into it
are used for uprobes/uretprobes that are created through tracefs or
perf events.

BPF is yet another user of uprobe/uretprobe infrastructure, but doesn't
need uprobe_cpu_buffer and associated data. For BPF-only use cases this
buffer handling and preparation is a pure overhead. At the same time,
BPF-only uprobe/uretprobe usage is very common in practice. Also, for
a lot of cases applications are very senstivie to performance overheads,
as they might be tracing a very high frequency functions like
malloc()/free(), so every bit of performance improvement matters.

All that is to say that this uprobe_cpu_buffer preparation is an
unnecessary overhead that each BPF user of uprobes/uretprobe has to pay.
This patch is changing this by making uprobe_cpu_buffer preparation
optional. It will happen only if either tracefs-based or perf event-based
uprobe/uretprobe consumer is registered for given uprobe/uretprobe. For
BPF-only use cases this step will be skipped.

We used uprobe/uretprobe benchmark which is part of BPF selftests (see [0])
to estimate the improvements. We have 3 uprobe and 3 uretprobe
scenarios, which vary an instruction that is replaced by uprobe: nop
(fastest uprobe case), `push rbp` (typical case), and non-simulated
`ret` instruction (slowest case). Benchmark thread is constantly calling
user space function in a tight loop. User space function has attached
BPF uprobe or uretprobe program doing nothing but atomic counter
increments to count number of triggering calls. Benchmark emits
throughput in millions of executions per second.

BEFORE these changes
====================
uprobe-nop     :    2.657 ± 0.024M/s
uprobe-push    :    2.499 ± 0.018M/s
uprobe-ret     :    1.100 ± 0.006M/s
uretprobe-nop  :    1.356 ± 0.004M/s
uretprobe-push :    1.317 ± 0.019M/s
uretprobe-ret  :    0.785 ± 0.007M/s

AFTER these changes
===================
uprobe-nop     :    2.732 ± 0.022M/s (+2.8%)
uprobe-push    :    2.621 ± 0.016M/s (+4.9%)
uprobe-ret     :    1.105 ± 0.007M/s (+0.5%)
uretprobe-nop  :    1.396 ± 0.007M/s (+2.9%)
uretprobe-push :    1.347 ± 0.008M/s (+2.3%)
uretprobe-ret  :    0.800 ± 0.006M/s (+1.9)

So the improvements on this particular machine seems to be between 2% and 5%.

  [0] https://github.com/torvalds/linux/blob/master/tools/testing/selftests/bpf/benchs/bench_trigger.c

Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/all/20240318181728.2795838-3-andrii@kernel.org/

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-05-01 23:18:46 +09:00
Andrii Nakryiko
3eaea21b4d uprobes: encapsulate preparation of uprobe args buffer 
Move the logic of fetching temporary per-CPU uprobe buffer and storing
uprobes args into it to a new helper function. Store data size as part
of this buffer, simplifying interfaces a bit, as now we only pass single
uprobe_cpu_buffer reference around, instead of pointer + dsize.

This logic was duplicated across uprobe_dispatcher and uretprobe_dispatcher,
and now will be centralized. All this is also in preparation to make
this uprobe_cpu_buffer handling logic optional in the next patch.

Link: https://lore.kernel.org/all/20240318181728.2795838-2-andrii@kernel.org/
[Masami: update for v6.9-rc3 kernel]

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-05-01 23:18:46 +09:00
Jiri Olsa
5c919acef8 bpf: Add support for kprobe session cookie 
Adding support for cookie within the session of kprobe multi
entry and return program.

The session cookie is u64 value and can be retrieved be new
kfunc bpf_session_cookie, which returns pointer to the cookie
value. The bpf program can use the pointer to store (on entry)
and load (on return) the value.

The cookie value is implemented via fprobe feature that allows
to share values between entry and return ftrace fprobe callbacks.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240430112830.1184228-4-jolsa@kernel.org
 2024-04-30 09:45:53 -07:00
Jiri Olsa
adf46d88ae bpf: Add support for kprobe session context 
Adding struct bpf_session_run_ctx object to hold session related
data, which is atm is_return bool and data pointer coming in
following changes.

Placing bpf_session_run_ctx layer in between bpf_run_ctx and
bpf_kprobe_multi_run_ctx so the session data can be retrieved
regardless of if it's kprobe_multi or uprobe_multi link, which
support is coming in future. This way both kprobe_multi and
uprobe_multi can use same kfuncs to access the session data.

Adding bpf_session_is_return kfunc that returns true if the
bpf program is executed from the exit probe of the kprobe multi
link attached in wrapper mode. It returns false otherwise.

Adding new kprobe hook for kprobe program type.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240430112830.1184228-3-jolsa@kernel.org
 2024-04-30 09:45:53 -07:00
Jiri Olsa
535a3692ba bpf: Add support for kprobe session attach 
Adding support to attach bpf program for entry and return probe
of the same function. This is common use case which at the moment
requires to create two kprobe multi links.

Adding new BPF_TRACE_KPROBE_SESSION attach type that instructs
kernel to attach single link program to both entry and exit probe.

It's possible to control execution of the bpf program on return
probe simply by returning zero or non zero from the entry bpf
program execution to execute or not the bpf program on return
probe respectively.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240430112830.1184228-2-jolsa@kernel.org
 2024-04-30 09:45:53 -07:00
Jakub Kicinski
89de2db193 bpf-next-for-netdev 
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-04-29

We've added 147 non-merge commits during the last 32 day(s) which contain
a total of 158 files changed, 9400 insertions(+), 2213 deletions(-).

The main changes are:

1) Add an internal-only BPF per-CPU instruction for resolving per-CPU
   memory addresses and implement support in x86 BPF JIT. This allows
   inlining per-CPU array and hashmap lookups
   and the bpf_get_smp_processor_id() helper, from Andrii Nakryiko.

2) Add BPF link support for sk_msg and sk_skb programs, from Yonghong Song.

3) Optimize x86 BPF JIT's emit_mov_imm64, and add support for various
   atomics in bpf_arena which can be JITed as a single x86 instruction,
   from Alexei Starovoitov.

4) Add support for passing mark with bpf_fib_lookup helper,
   from Anton Protopopov.

5) Add a new bpf_wq API for deferring events and refactor sleepable
   bpf_timer code to keep common code where possible,
   from Benjamin Tissoires.

6) Fix BPF_PROG_TEST_RUN infra with regards to bpf_dummy_struct_ops programs
   to check when NULL is passed for non-NULLable parameters,
   from Eduard Zingerman.

7) Harden the BPF verifier's and/or/xor value tracking,
   from Harishankar Vishwanathan.

8) Introduce crypto kfuncs to make BPF programs able to utilize the kernel
   crypto subsystem, from Vadim Fedorenko.

9) Various improvements to the BPF instruction set standardization doc,
   from Dave Thaler.

10) Extend libbpf APIs to partially consume items from the BPF ringbuffer,
    from Andrea Righi.

11) Bigger batch of BPF selftests refactoring to use common network helpers
    and to drop duplicate code, from Geliang Tang.

12) Support bpf_tail_call_static() helper for BPF programs with GCC 13,
    from Jose E. Marchesi.

13) Add bpf_preempt_{disable,enable}() kfuncs in order to allow a BPF
    program to have code sections where preemption is disabled,
    from Kumar Kartikeya Dwivedi.

14) Allow invoking BPF kfuncs from BPF_PROG_TYPE_SYSCALL programs,
    from David Vernet.

15) Extend the BPF verifier to allow different input maps for a given
    bpf_for_each_map_elem() helper call in a BPF program, from Philo Lu.

16) Add support for PROBE_MEM32 and bpf_addr_space_cast instructions
    for riscv64 and arm64 JITs to enable BPF Arena, from Puranjay Mohan.

17) Shut up a false-positive KMSAN splat in interpreter mode by unpoison
    the stack memory, from Martin KaFai Lau.

18) Improve xsk selftest coverage with new tests on maximum and minimum
    hardware ring size configurations, from Tushar Vyavahare.

19) Various ReST man pages fixes as well as documentation and bash completion
    improvements for bpftool, from Rameez Rehman & Quentin Monnet.

20) Fix libbpf with regards to dumping subsequent char arrays,
    from Quentin Deslandes.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (147 commits)
  bpf, docs: Clarify PC use in instruction-set.rst
  bpf_helpers.h: Define bpf_tail_call_static when building with GCC
  bpf, docs: Add introduction for use in the ISA Internet Draft
  selftests/bpf: extend BPF_SOCK_OPS_RTT_CB test for srtt and mrtt_us
  bpf: add mrtt and srtt as BPF_SOCK_OPS_RTT_CB args
  selftests/bpf: dummy_st_ops should reject 0 for non-nullable params
  bpf: check bpf_dummy_struct_ops program params for test runs
  selftests/bpf: do not pass NULL for non-nullable params in dummy_st_ops
  selftests/bpf: adjust dummy_st_ops_success to detect additional error
  bpf: mark bpf_dummy_struct_ops.test_1 parameter as nullable
  selftests/bpf: Add ring_buffer__consume_n test.
  bpf: Add bpf_guard_preempt() convenience macro
  selftests: bpf: crypto: add benchmark for crypto functions
  selftests: bpf: crypto skcipher algo selftests
  bpf: crypto: add skcipher to bpf crypto
  bpf: make common crypto API for TC/XDP programs
  bpf: update the comment for BTF_FIELDS_MAX
  selftests/bpf: Fix wq test.
  selftests/bpf: Use make_sockaddr in test_sock_addr
  selftests/bpf: Use connect_to_addr in test_sock_addr
  ...
====================

Link: https://lore.kernel.org/r/20240429131657.19423-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2024-04-29 13:12:19 -07:00
LuMingYin
dce3696271 tracing/probes: Fix memory leak in traceprobe_parse_probe_arg_body() 
If traceprobe_parse_probe_arg_body() failed to allocate 'parg->fmt',
it jumps to the label 'out' instead of 'fail' by mistake.In the result,
the buffer 'tmp' is not freed in this case and leaks its memory.

Thus jump to the label 'fail' in that error case.

Link: https://lore.kernel.org/all/20240427072347.1421053-1-lumingyindetect@126.com/

Fixes: 032330abd0 ("tracing/probes: Cleanup probe argument parser")
Signed-off-by: LuMingYin <lumingyindetect@126.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-04-29 22:30:46 +09:00
Arnd Bergmann
051e750307 blktrace: convert strncpy() to strscpy_pad() 
gcc-9 warns about a possibly non-terminated string copy:

kernel/trace/blktrace.c: In function 'do_blk_trace_setup':
kernel/trace/blktrace.c:527:2: error: 'strncpy' specified bound 32 equals destination size [-Werror=stringop-truncation]

Newer versions are fine here because they see the following explicit
nul-termination. Using strscpy_pad() avoids the warning and
simplifies the code a little. The padding helps  give a clean
buffer to userspace.

Link: https://lkml.kernel.org/r/20240409140059.3806717-5-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Justin Stitt <justinstitt@google.com>
Cc: Alexey Starikovskiy <astarikovskiy@suse.de>
Cc: Bob Moore <robert.moore@intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Len Brown <lenb@kernel.org>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: "Richard Russon (FlatCap)" <ldm@flatcap.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2024-04-25 21:07:08 -07:00
Joel Granados
66f20b11d3 ftrace: Remove the now superfluous sentinel elements from ctl_table array 
This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which
will reduce the overall build time size of the kernel and run time
memory bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)

Remove sentinel elements from ftrace_sysctls and user_event_sysctls

Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Joel Granados <j.granados@samsung.com>
 2024-04-24 09:43:53 +02:00
Jakub Kicinski
41e3ddb291 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 
Cross-merge networking fixes after downstream PR.

Conflicts:

include/trace/events/rpcgss.h
  386f4a7379 ("trace: events: cleanup deprecated strncpy uses")
  a4833e3aba ("SUNRPC: Fix rpcgss_context trace event acceptor field")

Adjacent changes:

drivers/net/ethernet/intel/ice/ice_tc_lib.c
  2cca35f5dd ("ice: Fix checking for unsupported keys on non-tunnel device")
  784feaa65d ("ice: Add support for PFCP hardware offload in switchdev")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2024-04-18 13:12:24 -07:00
Paul E. McKenney
64ec8b6ad6 ftrace: Choose RCU Tasks based on TASKS_RCU rather than PREEMPTION 
The advent of CONFIG_PREEMPT_AUTO, AKA lazy preemption, will mean that
even kernels built with CONFIG_PREEMPT_NONE or CONFIG_PREEMPT_VOLUNTARY
might see the occasional preemption, and that this preemption just might
happen within a trampoline.

Therefore, update ftrace_shutdown() to invoke synchronize_rcu_tasks()
based on CONFIG_TASKS_RCU instead of CONFIG_PREEMPTION.

[ paulmck: Apply Steven Rostedt feedback. ]

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Ankur Arora <ankur.a.arora@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <linux-trace-kernel@vger.kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
 2024-04-12 11:23:42 +02:00
Steven Rostedt (Google)
ffe3986fec ring-buffer: Only update pages_touched when a new page is touched 
The "buffer_percent" logic that is used by the ring buffer splice code to
only wake up the tasks when there's no data after the buffer is filled to
the percentage of the "buffer_percent" file is dependent on three
variables that determine the amount of data that is in the ring buffer:

 1) pages_read - incremented whenever a new sub-buffer is consumed
 2) pages_lost - incremented every time a writer overwrites a sub-buffer
 3) pages_touched - incremented when a write goes to a new sub-buffer

The percentage is the calculation of:

  (pages_touched - (pages_lost + pages_read)) / nr_pages

Basically, the amount of data is the total number of sub-bufs that have been
touched, minus the number of sub-bufs lost and sub-bufs consumed. This is
divided by the total count to give the buffer percentage. When the
percentage is greater than the value in the "buffer_percent" file, it
wakes up splice readers waiting for that amount.

It was observed that over time, the amount read from the splice was
constantly decreasing the longer the trace was running. That is, if one
asked for 60%, it would read over 60% when it first starts tracing, but
then it would be woken up at under 60% and would slowly decrease the
amount of data read after being woken up, where the amount becomes much
less than the buffer percent.

This was due to an accounting of the pages_touched incrementation. This
value is incremented whenever a writer transfers to a new sub-buffer. But
the place where it was incremented was incorrect. If a writer overflowed
the current sub-buffer it would go to the next one. If it gets preempted
by an interrupt at that time, and the interrupt performs a trace, it too
will end up going to the next sub-buffer. But only one should increment
the counter. Unfortunately, that was not the case.

Change the cmpxchg() that does the real switch of the tail-page into a
try_cmpxchg(), and on success, perform the increment of pages_touched. This
will only increment the counter once for when the writer moves to a new
sub-buffer, and not when there's a race and is incremented for when a
writer and its preempting writer both move to the same new sub-buffer.

Link: https://lore.kernel.org/linux-trace-kernel/20240409151309.0d0e5056@gandalf.local.home

Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 2c2b0a78b3 ("ring-buffer: Add percentage of ring buffer full to wake up reader")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-04-11 17:49:57 -04:00
Arnd Bergmann
5281ec8345 tracing: hide unused ftrace_event_id_fops 
When CONFIG_PERF_EVENTS, a 'make W=1' build produces a warning about the
unused ftrace_event_id_fops variable:

kernel/trace/trace_events.c:2155:37: error: 'ftrace_event_id_fops' defined but not used [-Werror=unused-const-variable=]
 2155 | static const struct file_operations ftrace_event_id_fops = {

Hide this in the same #ifdef as the reference to it.

Link: https://lore.kernel.org/linux-trace-kernel/20240403080702.3509288-7-arnd@kernel.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ajay Kaher <akaher@vmware.com>
Cc: Jinjie Ruan <ruanjinjie@huawei.com>
Cc: Clément Léger <cleger@rivosinc.com>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
Fixes: 620a30e97f ("tracing: Don't pass file_operations array to event_create_dir()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-04-11 17:46:55 -04:00
Prasad Pandit
d96c36004e tracing: Fix FTRACE_RECORD_RECURSION_SIZE Kconfig entry 
Fix FTRACE_RECORD_RECURSION_SIZE entry, replace tab with
a space character. It helps Kconfig parsers to read file
without error.

Link: https://lore.kernel.org/linux-trace-kernel/20240322121801.1803948-1-ppandit@redhat.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 773c167050 ("ftrace: Add recording of functions that caused recursion")
Signed-off-by: Prasad Pandit <pjp@fedoraproject.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-04-11 17:45:18 -04:00
Paul E. McKenney
02b3c5fcdf tracing: Select new NEED_TASKS_RCU Kconfig option 
Currently, if a Kconfig option depends on TASKS_RCU, it conditionally does
"select TASKS_RCU if PREEMPTION".  This works, but requires any change in
this enablement logic to be replicated across all such "select" clauses.
A new NEED_TASKS_RCU Kconfig option has been created to allow this
enablement logic to be in one place in kernel/rcu/Kconfig.

Therefore, select the new NEED_TASKS_RCU Kconfig option instead of the
old TASKS_RCU option.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: <linux-trace-kernel@vger.kernel.org>
Cc: Ankur Arora <ankur.a.arora@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
 2024-04-11 18:18:47 +02:00
Jakub Kicinski
cf1ca1f66d Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 
Cross-merge networking fixes after downstream PR.

Conflicts:

net/ipv4/ip_gre.c
  17af420545 ("erspan: make sure erspan_base_hdr is present in skb->head")
  5832c4a77d ("ip_tunnel: convert __be16 tunnel flags to bitmaps")
https://lore.kernel.org/all/20240402103253.3b54a1cf@canb.auug.org.au/

Adjacent changes:

net/ipv6/ip6_fib.c
  d21d40605b ("ipv6: Fix infinite recursion in fib6_dump_done().")
  5fc68320c1 ("ipv6: remove RTNL protection from inet6_dump_fib()")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2024-04-04 18:01:07 -07:00
Andrii Nakryiko
5e6a3c1ee6 bpf: make bpf_get_branch_snapshot() architecture-agnostic 
perf_snapshot_branch_stack is set up in an architecture-agnostic way, so
there is no reason for BPF subsystem to keep track of which
architectures do support LBR or not. E.g., it looks like ARM64 might soon
get support for BRBE ([0]), which (with proper integration) should be
possible to utilize using this BPF helper.

perf_snapshot_branch_stack static call will point to
__static_call_return0() by default, which just returns zero, which will
lead to -ENOENT, as expected. So no need to guard anything here.

  [0] https://lore.kernel.org/linux-arm-kernel/20240125094119.2542332-1-anshuman.khandual@arm.com/

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240404002640.1774210-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
 2024-04-04 13:08:01 -07:00
Alexander Lobakin
7d8296b250 bitops: make BYTES_TO_BITS() treewide-available 
Avoid open-coding that simple expression each time by moving
BYTES_TO_BITS() from the probes code to <linux/bitops.h> to export
it to the rest of the kernel.
Simplify the macro while at it. `BITS_PER_LONG / sizeof(long)` always
equals to %BITS_PER_BYTE, regardless of the target architecture.
Do the same for the tools ecosystem as well (incl. its version of
bitops.h). The previous implementation had its implicit type of long,
while the new one is int, so adjust the format literal accordingly in
the perf code.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Acked-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
 2024-04-01 10:49:27 +01:00
Andrii Nakryiko
1a80dbcb2d bpf: support deferring bpf_link dealloc to after RCU grace period 
BPF link for some program types is passed as a "context" which can be
used by those BPF programs to look up additional information. E.g., for
multi-kprobes and multi-uprobes, link is used to fetch BPF cookie values.

Because of this runtime dependency, when bpf_link refcnt drops to zero
there could still be active BPF programs running accessing link data.

This patch adds generic support to defer bpf_link dealloc callback to
after RCU GP, if requested. This is done by exposing two different
deallocation callbacks, one synchronous and one deferred. If deferred
one is provided, bpf_link_free() will schedule dealloc_deferred()
callback to happen after RCU GP.

BPF is using two flavors of RCU: "classic" non-sleepable one and RCU
tasks trace one. The latter is used when sleepable BPF programs are
used. bpf_link_free() accommodates that by checking underlying BPF
program's sleepable flag, and goes either through normal RCU GP only for
non-sleepable, or through RCU tasks trace GP *and* then normal RCU GP
(taking into account rcu_trace_implies_rcu_gp() optimization), if BPF
program is sleepable.

We use this for multi-kprobe and multi-uprobe links, which dereference
link during program run. We also preventively switch raw_tp link to use
deferred dealloc callback, as upcoming changes in bpf-next tree expose
raw_tp link data (specifically, cookie value) to BPF program at runtime
as well.

Fixes: 0dcac27254 ("bpf: Add multi kprobe link")
Fixes: 89ae89f53d ("bpf: Add multi uprobe link")
Reported-by: syzbot+981935d9485a560bfbcb@syzkaller.appspotmail.com
Reported-by: syzbot+2cb5a6c573e98db598cc@syzkaller.appspotmail.com
Reported-by: syzbot+62d8b26793e8a2bd0516@syzkaller.appspotmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20240328052426.3042617-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
 2024-03-28 18:47:45 -07:00
Andrii Nakryiko
e9c856cabe bpf: put uprobe link's path and task in release callback 
There is no need to delay putting either path or task to deallocation
step. It can be done right after bpf_uprobe_unregister. Between release
and dealloc, there could be still some running BPF programs, but they
don't access either task or path, only data in link->uprobes, so it is
safe to do.

On the other hand, doing path_put() in dealloc callback makes this
dealloc sleepable because path_put() itself might sleep. Which is
problematic due to the need to call uprobe's dealloc through call_rcu(),
which is what is done in the next bug fix patch. So solve the problem by
releasing these resources early.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240328052426.3042617-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
 2024-03-28 18:47:45 -07:00
Jakub Kicinski
5e47fbe5ce Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 
Cross-merge networking fixes after downstream PR.

No conflicts, or adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2024-03-28 17:25:57 -07:00
Linus Torvalds
962490525c Probes fixes for v6.9-rc1: 
- tracing/probes: initialize a 'val' local variable with zero. This variable
    is read by FETCH_OP_ST_EDATA in a loop, and is expected to be initialized
    by FETCH_OP_ARG in the same loop. Since this expectation is not obvious,
    thus smatch warns it. Initializing 'val' with zero fixes this warning.
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Merge tag 'probes-fixes-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes fixlet from Masami Hiramatsu:

 - tracing/probes: initialize a 'val' local variable with zero.

   This variable is read by FETCH_OP_ST_EDATA in a loop, and is
   initialized by FETCH_OP_ARG in the same loop. Since this
   initialization is not obvious, smatch warns about it.

   Explicitly initializing 'val' with zero fixes this warning.

* tag 'probes-fixes-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: probes: Fix to zero initialize a local variable
 2024-03-27 10:01:24 -07:00
Jakub Kicinski
2a702c2e57 bpf-next-for-netdev 
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-03-25

We've added 38 non-merge commits during the last 13 day(s) which contain
a total of 50 files changed, 867 insertions(+), 274 deletions(-).

The main changes are:

1) Add the ability to specify and retrieve BPF cookie also for raw
   tracepoint programs in order to ease migration from classic to raw
   tracepoints, from Andrii Nakryiko.

2) Allow the use of bpf_get_{ns_,}current_pid_tgid() helper for all
   program types and add additional BPF selftests, from Yonghong Song.

3) Several improvements to bpftool and its build, for example, enabling
   libbpf logs when loading pid_iter in debug mode, from Quentin Monnet.

4) Check the return code of all BPF-related set_memory_*() functions during
   load and bail out in case they fail, from Christophe Leroy.

5) Avoid a goto in regs_refine_cond_op() such that the verifier can
   be better integrated into Agni tool which doesn't support backedges
   yet, from Harishankar Vishwanathan.

6) Add a small BPF trie perf improvement by always inlining
   longest_prefix_match, from Jesper Dangaard Brouer.

7) Small BPF selftest refactor in bpf_tcp_ca.c to utilize start_server()
   helper instead of open-coding it, from Geliang Tang.

8) Improve test_tc_tunnel.sh BPF selftest to prevent client connect
   before the server bind, from Alessandro Carminati.

9) Fix BPF selftest benchmark for older glibc and use syscall(SYS_gettid)
   instead of gettid(), from Alan Maguire.

10) Implement a backward-compatible method for struct_ops types with
    additional fields which are not present in older kernels,
    from Kui-Feng Lee.

11) Add a small helper to check if an instruction is addr_space_cast
    from as(0) to as(1) and utilize it in x86-64 JIT, from Puranjay Mohan.

12) Small cleanup to remove unnecessary error check in
    bpf_struct_ops_map_update_elem, from Martin KaFai Lau.

13) Improvements to libbpf fd validity checks for BPF map/programs,
    from Mykyta Yatsenko.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (38 commits)
  selftests/bpf: Fix flaky test btf_map_in_map/lookup_update
  bpf: implement insn_is_cast_user() helper for JITs
  bpf: Avoid get_kernel_nofault() to fetch kprobe entry IP
  selftests/bpf: Use start_server in bpf_tcp_ca
  bpf: Sync uapi bpf.h to tools directory
  libbpf: Add new sec_def "sk_skb/verdict"
  selftests/bpf: Mark uprobe trigger functions with nocf_check attribute
  selftests/bpf: Use syscall(SYS_gettid) instead of gettid() wrapper in bench
  bpf-next: Avoid goto in regs_refine_cond_op()
  bpftool: Clean up HOST_CFLAGS, HOST_LDFLAGS for bootstrap bpftool
  selftests/bpf: scale benchmark counting by using per-CPU counters
  bpftool: Remove unnecessary source files from bootstrap version
  bpftool: Enable libbpf logs when loading pid_iter in debug mode
  selftests/bpf: add raw_tp/tp_btf BPF cookie subtests
  libbpf: add support for BPF cookie for raw_tp/tp_btf programs
  bpf: support BPF cookie in raw tracepoint (raw_tp, tp_btf) programs
  bpf: pass whole link instead of prog when triggering raw tracepoint
  bpf: flatten bpf_probe_register call chain
  selftests/bpf: Prevent client connect before server bind in test_tc_tunnel.sh
  selftests/bpf: Add a sk_msg prog bpf_get_ns_current_pid_tgid() test
  ...
====================

Link: https://lore.kernel.org/r/20240325233940.7154-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2024-03-27 07:52:34 -07:00
Andrii Nakryiko
a8497506cd bpf: Avoid get_kernel_nofault() to fetch kprobe entry IP 
get_kernel_nofault() (or, rather, underlying copy_from_kernel_nofault())
is not free and it does pop up in performance profiles when
kprobes are heavily utilized with CONFIG_X86_KERNEL_IBT=y config.

Let's avoid using it if we know that fentry_ip - 4 can't cross page
boundary. We do that by masking lowest 12 bits and checking if they are

Another benefit (and actually what caused a closer look at this part of
code) is that now LBR record is (typically) not wasted on
copy_from_kernel_nofault() call and code, which helps tools like
retsnoop that grab LBR records from inside BPF code in kretprobes.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/bpf/20240319212013.1046779-1-andrii@kernel.org
 2024-03-25 17:05:48 +01:00
Masami Hiramatsu (Google)
0add699ad0 tracing: probes: Fix to zero initialize a local variable 
Fix to initialize 'val' local variable with zero.
Dan reported that Smatch static code checker reports an error that a local
'val' variable needs to be initialized. Actually, the 'val' is expected to
be initialized by FETCH_OP_ARG in the same loop, but it is not obvious. So
initialize it with zero.

Link: https://lore.kernel.org/all/171092223833.237219.17304490075697026697.stgit@devnote2/

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/all/b010488e-68aa-407c-add0-3e059254aaa0@moroto.mountain/
Fixes: 25f00e40ce ("tracing/probes: Support $argN in return probe (kprobe and fprobe)")
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-03-25 16:24:31 +09:00
Andrii Nakryiko
68ca5d4eeb bpf: support BPF cookie in raw tracepoint (raw_tp, tp_btf) programs 
Wire up BPF cookie for raw tracepoint programs (both BTF and non-BTF
aware variants). This brings them up to part w.r.t. BPF cookie usage
with classic tracepoint and fentry/fexit programs.

Acked-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Message-ID: <20240319233852.1977493-4-andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
 2024-03-19 23:05:34 -07:00
Andrii Nakryiko
d4dfc5700e bpf: pass whole link instead of prog when triggering raw tracepoint 
Instead of passing prog as an argument to bpf_trace_runX() helpers, that
are called from tracepoint triggering calls, store BPF link itself
(struct bpf_raw_tp_link for raw tracepoints). This will allow to pass
extra information like BPF cookie into raw tracepoint registration.

Instead of replacing `struct bpf_prog *prog = __data;` with
corresponding `struct bpf_raw_tp_link *link = __data;` assignment in
`__bpf_trace_##call` I just passed `__data` through into underlying
bpf_trace_runX() call. This works well because we implicitly cast `void *`,
and it also avoids naming clashes with arguments coming from
tracepoint's "proto" list. We could have run into the same problem with
"prog", we just happened to not have a tracepoint that has "prog" input
argument. We are less lucky with "link", as there are tracepoints using
"link" argument name already. So instead of trying to avoid naming
conflicts, let's just remove intermediate local variable. It doesn't
hurt readibility, it's either way a bit of a maze of calls and macros,
that requires careful reading.

Acked-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Message-ID: <20240319233852.1977493-3-andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
 2024-03-19 23:05:33 -07:00
Andrii Nakryiko
6b9c2950c9 bpf: flatten bpf_probe_register call chain 
bpf_probe_register() and __bpf_probe_register() have identical
signatures and bpf_probe_register() just redirect to
__bpf_probe_register(). So get rid of this extra function call step to
simplify following the source code.

It has no difference at runtime due to inlining, of course.

Acked-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Message-ID: <20240319233852.1977493-2-andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
 2024-03-19 23:05:33 -07:00
Yonghong Song
eb166e522c bpf: Allow helper bpf_get_[ns_]current_pid_tgid() for all prog types 
Currently bpf_get_current_pid_tgid() is allowed in tracing, cgroup
and sk_msg progs while bpf_get_ns_current_pid_tgid() is only allowed
in tracing progs.

We have an internal use case where for an application running
in a container (with pid namespace), user wants to get
the pid associated with the pid namespace in a cgroup bpf
program. Currently, cgroup bpf progs already allow
bpf_get_current_pid_tgid(). Let us allow bpf_get_ns_current_pid_tgid()
as well.

With auditing the code, bpf_get_current_pid_tgid() is also used
by sk_msg prog. But there are no side effect to expose these two
helpers to all prog types since they do not reveal any kernel specific
data. The detailed discussion is in [1].

So with this patch, both bpf_get_current_pid_tgid() and bpf_get_ns_current_pid_tgid()
are put in bpf_base_func_proto(), making them available to all
program types.

  [1] https://lore.kernel.org/bpf/20240307232659.1115872-1-yonghong.song@linux.dev/

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240315184854.2975190-1-yonghong.song@linux.dev
 2024-03-19 14:24:07 -07:00
Thorsten Blum
d6cb38e108 tracing: Use div64_u64() instead of do_div() 
Fixes Coccinelle/coccicheck warnings reported by do_div.cocci.

Compared to do_div(), div64_u64() does not implicitly cast the divisor and
does not unnecessarily calculate the remainder.

Link: https://lore.kernel.org/linux-trace-kernel/20240225164507.232942-2-thorsten.blum@toblux.com

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-18 10:33:06 -04:00
Huang Yiwei
19f0423fd5 tracing: Support to dump instance traces by ftrace_dump_on_oops 
Currently ftrace only dumps the global trace buffer on an OOPs. For
debugging a production usecase, instance trace will be helpful to
check specific problems since global trace buffer may be used for
other purposes.

This patch extend the ftrace_dump_on_oops parameter to dump a specific
or multiple trace instances:

  - ftrace_dump_on_oops=0: as before -- don't dump
  - ftrace_dump_on_oops[=1]: as before -- dump the global trace buffer
  on all CPUs
  - ftrace_dump_on_oops=2 or =orig_cpu: as before -- dump the global
  trace buffer on CPU that triggered the oops
  - ftrace_dump_on_oops=<instance_name>: new behavior -- dump the
  tracing instance matching <instance_name>
  - ftrace_dump_on_oops[=2/orig_cpu],<instance1_name>[=2/orig_cpu],
  <instrance2_name>[=2/orig_cpu]: new behavior -- dump the global trace
  buffer and multiple instance buffer on all CPUs, or only dump on CPU
  that triggered the oops if =2 or =orig_cpu is given

Also, the sysctl node can handle the input accordingly.

Link: https://lore.kernel.org/linux-trace-kernel/20240223083126.1817731-1-quic_hyiwei@quicinc.com

Cc: Ross Zwisler <zwisler@google.com>
Cc: <mhiramat@kernel.org>
Cc: <mark.rutland@arm.com>
Cc: <mcgrof@kernel.org>
Cc: <keescook@chromium.org>
Cc: <j.granados@samsung.com>
Cc: <mathieu.desnoyers@efficios.com>
Cc: <corbet@lwn.net>
Signed-off-by: Huang Yiwei <quic_hyiwei@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-18 10:33:06 -04:00
Randy Dunlap
d15304135c ftrace: Fix most kernel-doc warnings 
Reduce the number of kernel-doc warnings from 52 down to 10, i.e.,
fix 42 kernel-doc warnings by (a) using the Returns: format for
function return values or (b) using "@var:" instead of "@var -"
for function parameter descriptions.

Fix one return values list so that it is formatted correctly when
rendered for output.

Spell "non-zero" with a hyphen in several places.

Link: https://lore.kernel.org/linux-trace-kernel/20240223054833.15471-1-rdunlap@infradead.org

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/oe-kbuild-all/202312180518.X6fRyDSN-lkp@intel.com/
Reported-by: kernel test robot <lkp@intel.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-18 10:33:05 -04:00
Steven Rostedt (Google)
2048fdc275 tracing: Decrement the snapshot if the snapshot trigger fails to register 
Running the ftrace selftests caused the ring buffer mapping test to fail.
Investigating, I found that the snapshot counter would be incremented
every time a snapshot trigger was added, even if that snapshot trigger
failed.

 # cd /sys/kernel/tracing
 # echo "snapshot" > events/sched/sched_process_fork/trigger
 # echo "snapshot" > events/sched/sched_process_fork/trigger
 -bash: echo: write error: File exists

That second one that fails increments the snapshot counter but doesn't
decrement it. It needs to be decremented when the snapshot fails.

Link: https://lore.kernel.org/linux-trace-kernel/20240223013344.729055907@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Fixes: 16f7e48ffc53a ("tracing: Add snapshot refcount")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-18 10:33:05 -04:00
Steven Rostedt (Google)
cca990c7b5 tracing: Fix snapshot counter going between two tracers that use it 
Running the ftrace selftests caused the ring buffer mapping test to fail.
Investigating, I found that the snapshot counter would be incremented
every time a tracer that uses the snapshot is enabled even if the snapshot
was used by the previous tracer.

That is:

 # cd /sys/kernel/tracing
 # echo wakeup_rt > current_tracer
 # echo wakeup_dl > current_tracer
 # echo nop > current_tracer

would leave the snapshot counter at 1 and not zero. That's because the
enabling of wakeup_dl would increment the counter again but the setting
the tracer to nop would only decrement it once.

Do not arm the snapshot for a tracer if the previous tracer already had it
armed.

Link: https://lore.kernel.org/linux-trace-kernel/20240223013344.570525723@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Fixes: 16f7e48ffc53a ("tracing: Add snapshot refcount")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-18 10:33:05 -04:00
John Garry
ed89683763 tracing: Use init_utsname()->release 
Instead of using UTS_RELEASE, use init_utsname()->release, which means that
we don't need to rebuild the code just for the git head commit changing.

Link: https://lore.kernel.org/linux-trace-kernel/20240222124639.65629-1-john.g.garry@oracle.com

Signed-off-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-18 10:13:21 -04:00
Beau Belgrave
64805e4039 tracing/user_events: Introduce multi-format events 
Currently user_events supports 1 event with the same name and must have
the exact same format when referenced by multiple programs. This opens
an opportunity for malicious or poorly thought through programs to
create events that others use with different formats. Another scenario
is user programs wishing to use the same event name but add more fields
later when the software updates. Various versions of a program may be
running side-by-side, which is prevented by the current single format
requirement.

Add a new register flag (USER_EVENT_REG_MULTI_FORMAT) which indicates
the user program wishes to use the same user_event name, but may have
several different formats of the event. When this flag is used, create
the underlying tracepoint backing the user_event with a unique name
per-version of the format. It's important that existing ABI users do
not get this logic automatically, even if one of the multi format
events matches the format. This ensures existing programs that create
events and assume the tracepoint name will match exactly continue to
work as expected. Add logic to only check multi-format events with
other multi-format events and single-format events to only check
single-format events during find.

Change system name of the multi-format event tracepoint to ensure that
multi-format events are isolated completely from single-format events.
This prevents single-format names from conflicting with multi-format
events if they end with the same suffix as the multi-format events.

Add a register_name (reg_name) to the user_event struct which allows for
split naming of events. We now have the name that was used to register
within user_events as well as the unique name for the tracepoint. Upon
registering events ensure matches based on first the reg_name, followed
by the fields and format of the event. This allows for multiple events
with the same registered name to have different formats. The underlying
tracepoint will have a unique name in the format of {reg_name}.{unique_id}.

For example, if both "test u32 value" and "test u64 value" are used with
the USER_EVENT_REG_MULTI_FORMAT the system would have 2 unique
tracepoints. The dynamic_events file would then show the following:
  u:test u64 count
  u:test u32 count

The actual tracepoint names look like this:
  test.0
  test.1

Both would be under the new user_events_multi system name to prevent the
older ABI from being used to squat on multi-formatted events and block
their use.

Deleting events via "!u:test u64 count" would only delete the first
tracepoint that matched that format. When the delete ABI is used all
events with the same name will be attempted to be deleted. If
per-version deletion is required, user programs should either not use
persistent events or delete them via dynamic_events.

Link: https://lore.kernel.org/linux-trace-kernel/20240222001807.1463-3-beaub@linux.microsoft.com

Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-18 10:13:03 -04:00
Beau Belgrave
1e953de9e9 tracing/user_events: Prepare find/delete for same name events 
The current code for finding and deleting events assumes that there will
never be cases when user_events are registered with the same name, but
different formats. Scenarios exist where programs want to use the same
name but have different formats. An example is multiple versions of a
program running side-by-side using the same event name, but with updated
formats in each version.

This change does not yet allow for multi-format events. If user_events
are registered with the same name but different arguments the programs
see the same return values as before. This change simply makes it
possible to easily accommodate for this.

Update find_user_event() to take in argument parameters and register
flags to accommodate future multi-format event scenarios. Have find
validate argument matching and return error pointers to cover when
an existing event has the same name but different format. Update
callers to handle error pointer logic.

Move delete_user_event() to use hash walking directly now that
find_user_event() has changed. Delete all events found that match the
register name, stop if an error occurs and report back to the user.

Update user_fields_match() to cover list_empty() scenarios now that
find_user_event() uses it directly. This makes the logic consistent
across several callsites.

Link: https://lore.kernel.org/linux-trace-kernel/20240222001807.1463-2-beaub@linux.microsoft.com

Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-18 10:12:54 -04:00
Vincent Donnefort
180e4e3909 tracing: Add snapshot refcount 
When a ring-buffer is memory mapped by user-space, no trace or
ring-buffer swap is possible. This means the snapshot feature is
mutually exclusive with the memory mapping. Having a refcount on
snapshot users will help to know if a mapping is possible or not.

Instead of relying on the global trace_types_lock, a new spinlock is
introduced to serialize accesses to trace_array->snapshot. This intends
to allow access to that variable in a context where the mmap lock is
already held.

Link: https://lore.kernel.org/linux-trace-kernel/20240220202310.2489614-4-vdonnefort@google.com

Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-18 10:12:47 -04:00
Steven Rostedt (Google)
b70f293824 ring-buffer: Make wake once of ring_buffer_wait() more robust 
The default behavior of ring_buffer_wait() when passed a NULL "cond"
parameter is to exit the function the first time it is woken up. The
current implementation uses a counter that starts at zero and when it is
greater than one it exits the wait_event_interruptible().

But this relies on the internal working of wait_event_interruptible() as
that code basically has:

  if (cond)
    return;
  prepare_to_wait();
  if (!cond)
    schedule();
  finish_wait();

That is, cond is called twice before it sleeps. The default cond of
ring_buffer_wait() needs to account for that and wait for its counter to
increment twice before exiting.

Instead, use the seq/atomic_inc logic that is used by the tracing code
that calls this function. Add an atomic_t seq to rb_irq_work and when cond
is NULL, have the default callback take a descriptor as its data that
holds the rbwork and the value of the seq when it started.

The wakeups will now increment the rbwork->seq and the cond callback will
simply check if that number is different, and no longer have to rely on
the implementation of wait_event_interruptible().

Link: https://lore.kernel.org/linux-trace-kernel/20240315063115.6cb5d205@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 7af9ded0c2 ("ring-buffer: Use wait_event_interruptible() in ring_buffer_wait()")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-18 10:11:43 -04:00
linke li
f1e30cb636 ring-buffer: use READ_ONCE() to read cpu_buffer->commit_page in concurrent environment 
In function ring_buffer_iter_empty(), cpu_buffer->commit_page is read
while other threads may change it. It may cause the time_stamp that read
in the next line come from a different page. Use READ_ONCE() to avoid
having to reason about compiler optimizations now and in future.

Link: https://lore.kernel.org/linux-trace-kernel/tencent_DFF7D3561A0686B5E8FC079150A02505180A@qq.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: linke li <lilinke99@qq.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-17 07:58:53 -04:00
Vincent Donnefort
6b76323e5a ring-buffer: Zero ring-buffer sub-buffers 
In preparation for the ring-buffer memory mapping where each subbuf will
be accessible to user-space, zero all the page allocations.

Link: https://lore.kernel.org/linux-trace-kernel/20240220202310.2489614-2-vdonnefort@google.com

Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-17 07:58:53 -04:00
Steven Rostedt (Google)
2cc621fd2e tracing: Move saved_cmdline code into trace_sched_switch.c 
The code that handles saved_cmdlines is split between the trace.c file and
the trace_sched_switch.c. There's some history to this. The
trace_sched_switch.c was originally created to handle the sched_switch
tracer that was deprecated due to sched_switch trace event making it
obsolete. But that file did not get deleted as it had some code to help
with saved_cmdlines. But trace.c has grown tremendously since then. Just
move all the saved_cmdlines code into trace_sched_switch.c as that's the
only reason that file still exists, and trace.c has gotten too big.

No functional changes.

Link: https://lore.kernel.org/linux-trace-kernel/20240220140703.497966629@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-17 07:58:53 -04:00
Steven Rostedt (Google)
e85d471c2b tracing: Move open coded processing of tgid_map into helper function 
In preparation of moving the saved_cmdlines logic out of trace.c and into
trace_sched_switch.c, replace the open coded manipulation of tgid_map in
set_tracer_flag() into a helper function trace_alloc_tgid_map() so that it
can be easily moved into trace_sched_switch.c without changing existing
functions in trace.c.

No functional changes.

Link: https://lore.kernel.org/linux-trace-kernel/20240220140703.338116216@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-17 07:58:52 -04:00
Steven Rostedt (Google)
0b18c852cc tracing: Have saved_cmdlines arrays all in one allocation 
The saved_cmdlines have three arrays for mapping PIDs to COMMs:

 - map_pid_to_cmdline[]
 - map_cmdline_to_pid[]
 - saved_cmdlines

The map_pid_to_cmdline[] is PID_MAX_DEFAULT in size and holds the index
into the other arrays. The map_cmdline_to_pid[] is a mapping back to the
full pid as it can be larger than PID_MAX_DEFAULT. And the
saved_cmdlines[] just holds the COMMs associated to the pids.

Currently the map_pid_to_cmdline[] and saved_cmdlines[] are allocated
together (in reality the saved_cmdlines is just in the memory of the
rounding of the allocation of the structure as it is always allocated in
powers of two). The map_cmdline_to_pid[] array is allocated separately.

Since the rounding to a power of two is rather large (it allows for 8000
elements in saved_cmdlines), also include the map_cmdline_to_pid[] array.
(This drops it to 6000 by default, which is still plenty for most use
cases). This saves even more memory as the map_cmdline_to_pid[] array
doesn't need to be allocated.

Link: https://lore.kernel.org/linux-trace-kernel/20240212174011.068211d9@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20240220140703.182330529@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Mete Durlu <meted@linux.ibm.com>
Fixes: 44dc5c41b5 ("tracing: Fix wasted memory in saved_cmdlines logic")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-17 07:58:52 -04:00
Linus Torvalds
63bd30f249 Tracing/ring-buffer fixes for 6.8 (to be applied in 6.9-rc): 
- Do not update shortest_full in rb_watermark_hit() if the watermark
   is hit. The shortest_full field was being updated regardless if
   the task was going to wait or not. If the watermark is hit, then
   the task is not going to wait, so do not update the shortest_full
   field (used by the waker).
 
 - Update shortest_full field before setting the full_waiters_pending flag
 
   In the poll logic, the full_waiters_pending flag was being set
   before the shortest_full field was set. If the full_waiters_pending
   flag is set, writers will check the shortest_full field which has
   the least percentage of data that the ring buffer needs to be
   filled before waking up. The writer will check shortest_full if
   full_waiters_pending is set, and if the ring buffer percentage filled
   is greater than shortest full, then it will call the irq_work to
   wake up the waiters.
 
   The problem was that the poll logic set the full_waiters_pending flag
   before updating shortest_full, which when zero will always trigger
   the writer to call the irq_work to wake up the waiters. The irq_work
   will reset the shortest_full field back to zero as the woken waiters
   is suppose to reset it.
 
 - There's some optimized logic in the rb_watermark_hit() that is used
   in ring_buffer_wait(). Use that helper function in the poll logic
   as well.
 
 - Restructure ring_buffer_wait() to use wait_event_interruptible()
 
   The logic to wake up pending readers when the file descriptor is
   closed is racy. Restructure ring_buffer_wait() to allow callers
   to pass in conditions besides the ring buffer having enough data
   in it by using wait_event_interruptible().
 
 - Update the tracing_wait_on_pipe() to call ring_buffer_wait() with
   its own conditions to exit the wait loop.
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Merge tag 'trace-ring-buffer-v6.8-rc7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing updates from Steven Rostedt:

 - Do not update shortest_full in rb_watermark_hit() if the watermark is
   hit. The shortest_full field was being updated regardless if the task
   was going to wait or not. If the watermark is hit, then the task is
   not going to wait, so do not update the shortest_full field (used by
   the waker).

 - Update shortest_full field before setting the full_waiters_pending
   flag

   In the poll logic, the full_waiters_pending flag was being set before
   the shortest_full field was set. If the full_waiters_pending flag is
   set, writers will check the shortest_full field which has the least
   percentage of data that the ring buffer needs to be filled before
   waking up. The writer will check shortest_full if
   full_waiters_pending is set, and if the ring buffer percentage filled
   is greater than shortest full, then it will call the irq_work to wake
   up the waiters.

   The problem was that the poll logic set the full_waiters_pending flag
   before updating shortest_full, which when zero will always trigger
   the writer to call the irq_work to wake up the waiters. The irq_work
   will reset the shortest_full field back to zero as the woken waiters
   is suppose to reset it.

 - There's some optimized logic in the rb_watermark_hit() that is used
   in ring_buffer_wait(). Use that helper function in the poll logic as
   well.

 - Restructure ring_buffer_wait() to use wait_event_interruptible()

   The logic to wake up pending readers when the file descriptor is
   closed is racy. Restructure ring_buffer_wait() to allow callers to
   pass in conditions besides the ring buffer having enough data in it
   by using wait_event_interruptible().

 - Update the tracing_wait_on_pipe() to call ring_buffer_wait() with its
   own conditions to exit the wait loop.

* tag 'trace-ring-buffer-v6.8-rc7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/ring-buffer: Fix wait_on_pipe() race
  ring-buffer: Use wait_event_interruptible() in ring_buffer_wait()
  ring-buffer: Reuse rb_watermark_hit() for the poll logic
  ring-buffer: Fix full_waiters_pending in poll
  ring-buffer: Do not set shortest_full when full target is hit
 2024-03-14 16:25:01 -07:00
Linus Torvalds
01732755ee Probes updates for v6.9: 
- x96/kprobes: Use boolean for some function return instead of 0 and 1.
  - x86/kprobes: Prohibit probing on INT/UD. This prevents user to put kprobe on
     INTn/INT1/INT3/INTO and UD0/UD1/UD2 because these are used for a special
     purpose in the kernel.
  - x86/kprobes: Boost Grp instructions. Because a few percent of kernel
     instructions are Grp 2/3/4/5 and those are safe to be executed without
     ip register fixup, allow those to be boosted (direct execution on the
     trampoline buffer with a JMP).
 
  - tracing/probes: Add function argument access from return events (kretprobe
     and fprobe). This allows user to compare how a data structure field is
     changed after executing a function. With BTF, return event also accepts
     function argument access by name. This also includes below patches;
   . Fix a wrong comment (using "Kretprobe" in fprobe)
   . Cleanup a big probe argument parser function into three parts, type
      parser, post-processing function, and main parser.
   . Cleanup to set nr_args field when initializing trace_probe instead of
      counting up it while parsing.
   . Cleanup a redundant #else block from tracefs/README source code.
   . Update selftests to check entry argument access from return probes.
   . Documentation update about entry argument access from return probes.
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Merge tag 'probes-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes updates from Masami Hiramatsu:
 "x86 kprobes:

   - Use boolean for some function return instead of 0 and 1

   - Prohibit probing on INT/UD. This prevents user to put kprobe on
     INTn/INT1/INT3/INTO and UD0/UD1/UD2 because these are used for a
     special purpose in the kernel

   - Boost Grp instructions. Because a few percent of kernel
     instructions are Grp 2/3/4/5 and those are safe to be executed
     without ip register fixup, allow those to be boosted (direct
     execution on the trampoline buffer with a JMP)

  tracing:

   - Add function argument access from return events (kretprobe and
     fprobe). This allows user to compare how a data structure field is
     changed after executing a function. With BTF, return event also
     accepts function argument access by name.

   - Fix a wrong comment (using "Kretprobe" in fprobe)

   - Cleanup a big probe argument parser function into three parts, type
     parser, post-processing function, and main parser

   - Cleanup to set nr_args field when initializing trace_probe instead
     of counting up it while parsing

   - Cleanup a redundant #else block from tracefs/README source code

   - Update selftests to check entry argument access from return probes

   - Documentation update about entry argument access from return
     probes"

* tag 'probes-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  Documentation: tracing: Add entry argument access at function exit
  selftests/ftrace: Add test cases for entry args at function exit
  tracing/probes: Support $argN in return probe (kprobe and fprobe)
  tracing: Remove redundant #else block for BTF args from README
  tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init
  tracing/probes: Cleanup probe argument parser
  tracing/fprobe-event: cleanup: Fix a wrong comment in fprobe event
  x86/kprobes: Boost more instructions from grp2/3/4/5
  x86/kprobes: Prohibit kprobing on INT and UD
  x86/kprobes: Refactor can_{probe,boost} return type to bool
 2024-03-14 16:16:33 -07:00
Linus Torvalds
9187210eee Networking changes for 6.9. 
Core & protocols
 ----------------
 
  - Large effort by Eric to lower rtnl_lock pressure and remove locks:
 
    - Make commonly used parts of rtnetlink (address, route dumps etc.)
      lockless, protected by RCU instead of rtnl_lock.
 
    - Add a netns exit callback which already holds rtnl_lock,
      allowing netns exit to take rtnl_lock once in the core
      instead of once for each driver / callback.
 
    - Remove locks / serialization in the socket diag interface.
 
    - Remove 6 calls to synchronize_rcu() while holding rtnl_lock.
 
    - Remove the dev_base_lock, depend on RCU where necessary.
 
  - Support busy polling on a per-epoll context basis. Poll length
    and budget parameters can be set independently of system defaults.
 
  - Introduce struct net_hotdata, to make sure read-mostly global config
    variables fit in as few cache lines as possible.
 
  - Add optional per-nexthop statistics to ease monitoring / debug
    of ECMP imbalance problems.
 
  - Support TCP_NOTSENT_LOWAT in MPTCP.
 
  - Ensure that IPv6 temporary addresses' preferred lifetimes are long
    enough, compared to other configured lifetimes, and at least 2 sec.
 
  - Support forwarding of ICMP Error messages in IPSec, per RFC 4301.
 
  - Add support for the independent control state machine for bonding
    per IEEE 802.1AX-2008 5.4.15 in addition to the existing coupled
    control state machine.
 
  - Add "network ID" to MCTP socket APIs to support hosts with multiple
    disjoint MCTP networks.
 
  - Re-use the mono_delivery_time skbuff bit for packets which user
    space wants to be sent at a specified time. Maintain the timing
    information while traversing veth links, bridge etc.
 
  - Take advantage of MSG_SPLICE_PAGES for RxRPC DATA and ACK packets.
 
  - Simplify many places iterating over netdevs by using an xarray
    instead of a hash table walk (hash table remains in place, for
    use on fastpaths).
 
  - Speed up scanning for expired routes by keeping a dedicated list.
 
  - Speed up "generic" XDP by trying harder to avoid large allocations.
 
  - Support attaching arbitrary metadata to netconsole messages.
 
 Things we sprinkled into general kernel code
 --------------------------------------------
 
  - Enforce VM_IOREMAP flag and range in ioremap_page_range and introduce
    VM_SPARSE kind and vm_area_[un]map_pages (used by bpf_arena).
 
  - Rework selftest harness to enable the use of the full range of
    ksft exit code (pass, fail, skip, xfail, xpass).
 
 Netfilter
 ---------
 
  - Allow userspace to define a table that is exclusively owned by a daemon
    (via netlink socket aliveness) without auto-removing this table when
    the userspace program exits. Such table gets marked as orphaned and
    a restarting management daemon can re-attach/regain ownership.
 
  - Speed up element insertions to nftables' concatenated-ranges set type.
    Compact a few related data structures.
 
 BPF
 ---
 
  - Add BPF token support for delegating a subset of BPF subsystem
    functionality from privileged system-wide daemons such as systemd
    through special mount options for userns-bound BPF fs to a trusted
    & unprivileged application.
 
  - Introduce bpf_arena which is sparse shared memory region between BPF
    program and user space where structures inside the arena can have
    pointers to other areas of the arena, and pointers work seamlessly
    for both user-space programs and BPF programs.
 
  - Introduce may_goto instruction that is a contract between the verifier
    and the program. The verifier allows the program to loop assuming it's
    behaving well, but reserves the right to terminate it.
 
  - Extend the BPF verifier to enable static subprog calls in spin lock
    critical sections.
 
  - Support registration of struct_ops types from modules which helps
    projects like fuse-bpf that seeks to implement a new struct_ops type.
 
  - Add support for retrieval of cookies for perf/kprobe multi links.
 
  - Support arbitrary TCP SYN cookie generation / validation in the TC
    layer with BPF to allow creating SYN flood handling in BPF firewalls.
 
  - Add code generation to inline the bpf_kptr_xchg() helper which
    improves performance when stashing/popping the allocated BPF objects.
 
 Wireless
 --------
 
  - Add SPP (signaling and payload protected) AMSDU support.
 
  - Support wider bandwidth OFDMA, as required for EHT operation.
 
 Driver API
 ----------
 
  - Major overhaul of the Energy Efficient Ethernet internals to support
    new link modes (2.5GE, 5GE), share more code between drivers
    (especially those using phylib), and encourage more uniform behavior.
    Convert and clean up drivers.
 
  - Define an API for querying per netdev queue statistics from drivers.
 
  - IPSec: account in global stats for fully offloaded sessions.
 
  - Create a concept of Ethernet PHY Packages at the Device Tree level,
    to allow parameterizing the existing PHY package code.
 
  - Enable Rx hashing (RSS) on GTP protocol fields.
 
 Misc
 ----
 
  - Improvements and refactoring all over networking selftests.
 
  - Create uniform module aliases for TC classifiers, actions,
    and packet schedulers to simplify creating modprobe policies.
 
  - Address all missing MODULE_DESCRIPTION() warnings in networking.
 
  - Extend the Netlink descriptions in YAML to cover message encapsulation
    or "Netlink polymorphism", where interpretation of nested attributes
    depends on link type, classifier type or some other "class type".
 
 Drivers
 -------
 
  - Ethernet high-speed NICs:
    - Add a new driver for Marvell's Octeon PCI Endpoint NIC VF.
    - Intel (100G, ice, idpf):
      - support E825-C devices
    - nVidia/Mellanox:
      - support devices with one port and multiple PCIe links
    - Broadcom (bnxt):
      - support n-tuple filters
      - support configuring the RSS key
    - Wangxun (ngbe/txgbe):
      - implement irq_domain for TXGBE's sub-interrupts
    - Pensando/AMD:
      - support XDP
      - optimize queue submission and wakeup handling (+17% bps)
      - optimize struct layout, saving 28% of memory on queues
 
  - Ethernet NICs embedded and virtual:
    - Google cloud vNIC:
      - refactor driver to perform memory allocations for new queue
        config before stopping and freeing the old queue memory
    - Synopsys (stmmac):
      - obey queueMaxSDU and implement counters required by 802.1Qbv
    - Renesas (ravb):
      - support packet checksum offload
      - suspend to RAM and runtime PM support
 
  - Ethernet switches:
    - nVidia/Mellanox:
      - support for nexthop group statistics
    - Microchip:
      - ksz8: implement PHY loopback
      - add support for KSZ8567, a 7-port 10/100Mbps switch
 
  - PTP:
    - New driver for RENESAS FemtoClock3 Wireless clock generator.
    - Support OCP PTP cards designed and built by Adva.
 
  - CAN:
    - Support recvmsg() flags for own, local and remote traffic
      on CAN BCM sockets.
    - Support for esd GmbH PCIe/402 CAN device family.
    - m_can:
      - Rx/Tx submission coalescing
      - wake on frame Rx
 
  - WiFi:
    - Intel (iwlwifi):
      - enable signaling and payload protected A-MSDUs
      - support wider-bandwidth OFDMA
      - support for new devices
      - bump FW API to 89 for AX devices; 90 for BZ/SC devices
    - MediaTek (mt76):
      - mt7915: newer ADIE version support
      - mt7925: radio temperature sensor support
    - Qualcomm (ath11k):
      - support 6 GHz station power modes: Low Power Indoor (LPI),
        Standard Power) SP and Very Low Power (VLP)
      - QCA6390 & WCN6855: support 2 concurrent station interfaces
      - QCA2066 support
    - Qualcomm (ath12k):
      - refactoring in preparation for Multi-Link Operation (MLO) support
      - 1024 Block Ack window size support
      - firmware-2.bin support
      - support having multiple identical PCI devices (firmware needs to
        have ATH12K_FW_FEATURE_MULTI_QRTR_ID)
      - QCN9274: support split-PHY devices
      - WCN7850: enable Power Save Mode in station mode
      - WCN7850: P2P support
    - RealTek:
      - rtw88: support for more rtw8811cu and rtw8821cu devices
      - rtw89: support SCAN_RANDOM_SN and SET_SCAN_DWELL
      - rtlwifi: speed up USB firmware initialization
      - rtwl8xxxu:
        - RTL8188F: concurrent interface support
        - Channel Switch Announcement (CSA) support in AP mode
    - Broadcom (brcmfmac):
      - per-vendor feature support
      - per-vendor SAE password setup
      - DMI nvram filename quirk for ACEPC W5 Pro
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "Core & protocols:

   - Large effort by Eric to lower rtnl_lock pressure and remove locks:

      - Make commonly used parts of rtnetlink (address, route dumps
        etc) lockless, protected by RCU instead of rtnl_lock.

      - Add a netns exit callback which already holds rtnl_lock,
        allowing netns exit to take rtnl_lock once in the core instead
        of once for each driver / callback.

      - Remove locks / serialization in the socket diag interface.

      - Remove 6 calls to synchronize_rcu() while holding rtnl_lock.

      - Remove the dev_base_lock, depend on RCU where necessary.

   - Support busy polling on a per-epoll context basis. Poll length and
     budget parameters can be set independently of system defaults.

   - Introduce struct net_hotdata, to make sure read-mostly global
     config variables fit in as few cache lines as possible.

   - Add optional per-nexthop statistics to ease monitoring / debug of
     ECMP imbalance problems.

   - Support TCP_NOTSENT_LOWAT in MPTCP.

   - Ensure that IPv6 temporary addresses' preferred lifetimes are long
     enough, compared to other configured lifetimes, and at least 2 sec.

   - Support forwarding of ICMP Error messages in IPSec, per RFC 4301.

   - Add support for the independent control state machine for bonding
     per IEEE 802.1AX-2008 5.4.15 in addition to the existing coupled
     control state machine.

   - Add "network ID" to MCTP socket APIs to support hosts with multiple
     disjoint MCTP networks.

   - Re-use the mono_delivery_time skbuff bit for packets which user
     space wants to be sent at a specified time. Maintain the timing
     information while traversing veth links, bridge etc.

   - Take advantage of MSG_SPLICE_PAGES for RxRPC DATA and ACK packets.

   - Simplify many places iterating over netdevs by using an xarray
     instead of a hash table walk (hash table remains in place, for use
     on fastpaths).

   - Speed up scanning for expired routes by keeping a dedicated list.

   - Speed up "generic" XDP by trying harder to avoid large allocations.

   - Support attaching arbitrary metadata to netconsole messages.

  Things we sprinkled into general kernel code:

   - Enforce VM_IOREMAP flag and range in ioremap_page_range and
     introduce VM_SPARSE kind and vm_area_[un]map_pages (used by
     bpf_arena).

   - Rework selftest harness to enable the use of the full range of ksft
     exit code (pass, fail, skip, xfail, xpass).

  Netfilter:

   - Allow userspace to define a table that is exclusively owned by a
     daemon (via netlink socket aliveness) without auto-removing this
     table when the userspace program exits. Such table gets marked as
     orphaned and a restarting management daemon can re-attach/regain
     ownership.

   - Speed up element insertions to nftables' concatenated-ranges set
     type. Compact a few related data structures.

  BPF:

   - Add BPF token support for delegating a subset of BPF subsystem
     functionality from privileged system-wide daemons such as systemd
     through special mount options for userns-bound BPF fs to a trusted
     & unprivileged application.

   - Introduce bpf_arena which is sparse shared memory region between
     BPF program and user space where structures inside the arena can
     have pointers to other areas of the arena, and pointers work
     seamlessly for both user-space programs and BPF programs.

   - Introduce may_goto instruction that is a contract between the
     verifier and the program. The verifier allows the program to loop
     assuming it's behaving well, but reserves the right to terminate
     it.

   - Extend the BPF verifier to enable static subprog calls in spin lock
     critical sections.

   - Support registration of struct_ops types from modules which helps
     projects like fuse-bpf that seeks to implement a new struct_ops
     type.

   - Add support for retrieval of cookies for perf/kprobe multi links.

   - Support arbitrary TCP SYN cookie generation / validation in the TC
     layer with BPF to allow creating SYN flood handling in BPF
     firewalls.

   - Add code generation to inline the bpf_kptr_xchg() helper which
     improves performance when stashing/popping the allocated BPF
     objects.

  Wireless:

   - Add SPP (signaling and payload protected) AMSDU support.

   - Support wider bandwidth OFDMA, as required for EHT operation.

  Driver API:

   - Major overhaul of the Energy Efficient Ethernet internals to
     support new link modes (2.5GE, 5GE), share more code between
     drivers (especially those using phylib), and encourage more
     uniform behavior. Convert and clean up drivers.

   - Define an API for querying per netdev queue statistics from
     drivers.

   - IPSec: account in global stats for fully offloaded sessions.

   - Create a concept of Ethernet PHY Packages at the Device Tree level,
     to allow parameterizing the existing PHY package code.

   - Enable Rx hashing (RSS) on GTP protocol fields.

  Misc:

   - Improvements and refactoring all over networking selftests.

   - Create uniform module aliases for TC classifiers, actions, and
     packet schedulers to simplify creating modprobe policies.

   - Address all missing MODULE_DESCRIPTION() warnings in networking.

   - Extend the Netlink descriptions in YAML to cover message
     encapsulation or "Netlink polymorphism", where interpretation of
     nested attributes depends on link type, classifier type or some
     other "class type".

  Drivers:

   - Ethernet high-speed NICs:
      - Add a new driver for Marvell's Octeon PCI Endpoint NIC VF.
      - Intel (100G, ice, idpf):
         - support E825-C devices
      - nVidia/Mellanox:
         - support devices with one port and multiple PCIe links
      - Broadcom (bnxt):
         - support n-tuple filters
         - support configuring the RSS key
      - Wangxun (ngbe/txgbe):
         - implement irq_domain for TXGBE's sub-interrupts
      - Pensando/AMD:
         - support XDP
         - optimize queue submission and wakeup handling (+17% bps)
         - optimize struct layout, saving 28% of memory on queues

   - Ethernet NICs embedded and virtual:
      - Google cloud vNIC:
         - refactor driver to perform memory allocations for new queue
           config before stopping and freeing the old queue memory
      - Synopsys (stmmac):
         - obey queueMaxSDU and implement counters required by 802.1Qbv
      - Renesas (ravb):
         - support packet checksum offload
         - suspend to RAM and runtime PM support

   - Ethernet switches:
      - nVidia/Mellanox:
         - support for nexthop group statistics
      - Microchip:
         - ksz8: implement PHY loopback
         - add support for KSZ8567, a 7-port 10/100Mbps switch

   - PTP:
      - New driver for RENESAS FemtoClock3 Wireless clock generator.
      - Support OCP PTP cards designed and built by Adva.

   - CAN:
      - Support recvmsg() flags for own, local and remote traffic on CAN
        BCM sockets.
      - Support for esd GmbH PCIe/402 CAN device family.
      - m_can:
         - Rx/Tx submission coalescing
         - wake on frame Rx

   - WiFi:
      - Intel (iwlwifi):
         - enable signaling and payload protected A-MSDUs
         - support wider-bandwidth OFDMA
         - support for new devices
         - bump FW API to 89 for AX devices; 90 for BZ/SC devices
      - MediaTek (mt76):
         - mt7915: newer ADIE version support
         - mt7925: radio temperature sensor support
      - Qualcomm (ath11k):
         - support 6 GHz station power modes: Low Power Indoor (LPI),
           Standard Power) SP and Very Low Power (VLP)
         - QCA6390 & WCN6855: support 2 concurrent station interfaces
         - QCA2066 support
      - Qualcomm (ath12k):
         - refactoring in preparation for Multi-Link Operation (MLO)
           support
         - 1024 Block Ack window size support
         - firmware-2.bin support
         - support having multiple identical PCI devices (firmware needs
           to have ATH12K_FW_FEATURE_MULTI_QRTR_ID)
         - QCN9274: support split-PHY devices
         - WCN7850: enable Power Save Mode in station mode
         - WCN7850: P2P support
      - RealTek:
         - rtw88: support for more rtw8811cu and rtw8821cu devices
         - rtw89: support SCAN_RANDOM_SN and SET_SCAN_DWELL
         - rtlwifi: speed up USB firmware initialization
         - rtwl8xxxu:
             - RTL8188F: concurrent interface support
             - Channel Switch Announcement (CSA) support in AP mode
      - Broadcom (brcmfmac):
         - per-vendor feature support
         - per-vendor SAE password setup
         - DMI nvram filename quirk for ACEPC W5 Pro"

* tag 'net-next-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2255 commits)
  nexthop: Fix splat with CONFIG_DEBUG_PREEMPT=y
  nexthop: Fix out-of-bounds access during attribute validation
  nexthop: Only parse NHA_OP_FLAGS for dump messages that require it
  nexthop: Only parse NHA_OP_FLAGS for get messages that require it
  bpf: move sleepable flag from bpf_prog_aux to bpf_prog
  bpf: hardcode BPF_PROG_PACK_SIZE to 2MB * num_possible_nodes()
  selftests/bpf: Add kprobe multi triggering benchmarks
  ptp: Move from simple ida to xarray
  vxlan: Remove generic .ndo_get_stats64
  vxlan: Do not alloc tstats manually
  devlink: Add comments to use netlink gen tool
  nfp: flower: handle acti_netdevs allocation failure
  net/packet: Add getsockopt support for PACKET_COPY_THRESH
  net/netlink: Add getsockopt support for NETLINK_LISTEN_ALL_NSID
  selftests/bpf: Add bpf_arena_htab test.
  selftests/bpf: Add bpf_arena_list test.
  selftests/bpf: Add unit tests for bpf_arena_alloc/free_pages
  bpf: Add helper macro bpf_addr_space_cast()
  libbpf: Recognize __arena global variables.
  bpftool: Recognize arena map type
  ...
 2024-03-12 17:44:08 -07:00
Steven Rostedt (Google)
2aa043a55b tracing/ring-buffer: Fix wait_on_pipe() race 
When the trace_pipe_raw file is closed, there should be no new readers on
the file descriptor. This is mostly handled with the waking and wait_index
fields of the iterator. But there's still a slight race.

     CPU 0                              CPU 1
     -----                              -----
                                   wait_index++;
   index = wait_index;
                                   ring_buffer_wake_waiters();
   wait_on_pipe()
     ring_buffer_wait();

The ring_buffer_wait() will miss the wakeup from CPU 1. The problem is
that the ring_buffer_wait() needs the logic of:

        prepare_to_wait();
        if (!condition)
                schedule();

Where the missing condition check is the iter->wait_index update.

Have the ring_buffer_wait() take a conditional callback function and a
data parameter that can be used within the wait_event_interruptible() of
the ring_buffer_wait() function.

In wait_on_pipe(), pass a condition function that will check if the
wait_index has been updated, if it has, it will return true to break out
of the wait_event_interruptible() loop.

Create a new field "closed" in the trace_iterator and set it in the
.flush() callback before calling ring_buffer_wake_waiters().
This will keep any new readers from waiting on a closed file descriptor.

Have the wait_on_pipe() condition callback also check the closed field.

Change the wait_index field of the trace_iterator to atomic_t. There's no
reason it needs to be 'long' and making it atomic and using
atomic_read_acquire() and atomic_fetch_inc_release() will provide the
necessary memory barriers.

Add a "woken" flag to tracing_buffers_splice_read() to exit the loop after
one more try to fetch data. That is, if it waited for data and something
woke it up, it should try to collect any new data and then exit back to
user space.

Link: https://lore.kernel.org/linux-trace-kernel/CAHk-=wgsNgewHFxZAJiAQznwPMqEtQmi1waeS2O1v6L4c_Um5A@mail.gmail.com/
Link: https://lore.kernel.org/linux-trace-kernel/20240312121703.557950713@goodmis.org

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linke li <lilinke99@qq.com>
Cc: Rabin Vincent <rabin@rab.in>
Fixes: f3ddb74ad0 ("tracing: Wake up ring buffer waiters on closing of the file")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-12 12:44:48 -04:00
Steven Rostedt (Google)
7af9ded0c2 ring-buffer: Use wait_event_interruptible() in ring_buffer_wait() 
Convert ring_buffer_wait() over to wait_event_interruptible(). The default
condition is to execute the wait loop inside __wait_event() just once.

This does not change the ring_buffer_wait() prototype yet, but
restructures the code so that it can take a "cond" and "data" parameter
and will call wait_event_interruptible() with a helper function as the
condition.

The helper function (rb_wait_cond) takes the cond function and data
parameters. It will first check if the buffer hit the watermark defined by
the "full" parameter and then call the passed in condition parameter. If
either are true, it returns true.

If rb_wait_cond() does not return true, it will set the appropriate
"waiters_pending" flag and returns false.

Link: https://lore.kernel.org/linux-trace-kernel/CAHk-=wgsNgewHFxZAJiAQznwPMqEtQmi1waeS2O1v6L4c_Um5A@mail.gmail.com/
Link: https://lore.kernel.org/linux-trace-kernel/20240312121703.399598519@goodmis.org

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linke li <lilinke99@qq.com>
Cc: Rabin Vincent <rabin@rab.in>
Fixes: f3ddb74ad0 ("tracing: Wake up ring buffer waiters on closing of the file")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-12 12:44:35 -04:00
Steven Rostedt (Google)
e36f19a645 ring-buffer: Reuse rb_watermark_hit() for the poll logic 
The check for knowing if the poll should wait or not is basically the
exact same logic as rb_watermark_hit(). The only difference is that
rb_watermark_hit() also handles the !full case. But for the full case, the
logic is the same. Just call that instead of duplicating the code in
ring_buffer_poll_wait().

Link: https://lore.kernel.org/linux-trace-kernel/20240312131952.802267543@goodmis.org

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-12 12:44:07 -04:00
Steven Rostedt (Google)
8145f1c35f ring-buffer: Fix full_waiters_pending in poll 
If a reader of the ring buffer is doing a poll, and waiting for the ring
buffer to hit a specific watermark, there could be a case where it gets
into an infinite ping-pong loop.

The poll code has:

  rbwork->full_waiters_pending = true;
  if (!cpu_buffer->shortest_full ||
      cpu_buffer->shortest_full > full)
         cpu_buffer->shortest_full = full;

The writer will see full_waiters_pending and check if the ring buffer is
filled over the percentage of the shortest_full value. If it is, it calls
an irq_work to wake up all the waiters.

But the code could get into a circular loop:

	CPU 0					CPU 1
	-----					-----
 [ Poll ]
   [ shortest_full = 0 ]
   rbwork->full_waiters_pending = true;
					  if (rbwork->full_waiters_pending &&
					      [ buffer percent ] > shortest_full) {
					         rbwork->wakeup_full = true;
					         [ queue_irqwork ]

   cpu_buffer->shortest_full = full;

					  [ IRQ work ]
					  if (rbwork->wakeup_full) {
					        cpu_buffer->shortest_full = 0;
					        wakeup poll waiters;
  [woken]
   if ([ buffer percent ] > full)
      break;
   rbwork->full_waiters_pending = true;
					  if (rbwork->full_waiters_pending &&
					      [ buffer percent ] > shortest_full) {
					         rbwork->wakeup_full = true;
					         [ queue_irqwork ]

   cpu_buffer->shortest_full = full;

					  [ IRQ work ]
					  if (rbwork->wakeup_full) {
					        cpu_buffer->shortest_full = 0;
					        wakeup poll waiters;
  [woken]

 [ Wash, rinse, repeat! ]

In the poll, the shortest_full needs to be set before the
full_pending_waiters, as once that is set, the writer will compare the
current shortest_full (which is incorrect) to decide to call the irq_work,
which will reset the shortest_full (expecting the readers to update it).

Also move the setting of full_waiters_pending after the check if the ring
buffer has the required percentage filled. There's no reason to tell the
writer to wake up waiters if there are no waiters.

Link: https://lore.kernel.org/linux-trace-kernel/20240312131952.630922155@goodmis.org

Cc: stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 42fb0a1e84 ("tracing/ring-buffer: Have polling block on watermark")
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-12 12:43:30 -04:00
Steven Rostedt (Google)
761d9473e2 ring-buffer: Do not set shortest_full when full target is hit 
The rb_watermark_hit() checks if the amount of data in the ring buffer is
above the percentage level passed in by the "full" variable. If it is, it
returns true.

But it also sets the "shortest_full" field of the cpu_buffer that informs
writers that it needs to call the irq_work if the amount of data on the
ring buffer is above the requested amount.

The rb_watermark_hit() always sets the shortest_full even if the amount in
the ring buffer is what it wants. As it is not going to wait, because it
has what it wants, there's no reason to set shortest_full.

Link: https://lore.kernel.org/linux-trace-kernel/20240312115641.6aa8ba08@gandalf.local.home

Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 42fb0a1e84 ("tracing/ring-buffer: Have polling block on watermark")
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-12 12:40:28 -04:00
Linus Torvalds
685d982112 Core x86 changes for v6.9: 
- The biggest change is the rework of the percpu code,
   to support the 'Named Address Spaces' GCC feature,
   by Uros Bizjak:
 
    - This allows C code to access GS and FS segment relative
      memory via variables declared with such attributes,
      which allows the compiler to better optimize those accesses
      than the previous inline assembly code.
 
    - The series also includes a number of micro-optimizations
      for various percpu access methods, plus a number of
      cleanups of %gs accesses in assembly code.
 
    - These changes have been exposed to linux-next testing for
      the last ~5 months, with no known regressions in this area.
 
 - Fix/clean up __switch_to()'s broken but accidentally
   working handling of FPU switching - which also generates
   better code.
 
 - Propagate more RIP-relative addressing in assembly code,
   to generate slightly better code.
 
 - Rework the CPU mitigations Kconfig space to be less idiosyncratic,
   to make it easier for distros to follow & maintain these options.
 
 - Rework the x86 idle code to cure RCU violations and
   to clean up the logic.
 
 - Clean up the vDSO Makefile logic.
 
 - Misc cleanups and fixes.
 
 [ Please note that there's a higher number of merge commits in
   this branch (three) than is usual in x86 topic trees. This happened
   due to the long testing lifecycle of the percpu changes that
   involved 3 merge windows, which generated a longer history
   and various interactions with other core x86 changes that we
   felt better about to carry in a single branch. ]
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-core-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core x86 updates from Ingo Molnar:

 - The biggest change is the rework of the percpu code, to support the
   'Named Address Spaces' GCC feature, by Uros Bizjak:

      - This allows C code to access GS and FS segment relative memory
        via variables declared with such attributes, which allows the
        compiler to better optimize those accesses than the previous
        inline assembly code.

      - The series also includes a number of micro-optimizations for
        various percpu access methods, plus a number of cleanups of %gs
        accesses in assembly code.

      - These changes have been exposed to linux-next testing for the
        last ~5 months, with no known regressions in this area.

 - Fix/clean up __switch_to()'s broken but accidentally working handling
   of FPU switching - which also generates better code

 - Propagate more RIP-relative addressing in assembly code, to generate
   slightly better code

 - Rework the CPU mitigations Kconfig space to be less idiosyncratic, to
   make it easier for distros to follow & maintain these options

 - Rework the x86 idle code to cure RCU violations and to clean up the
   logic

 - Clean up the vDSO Makefile logic

 - Misc cleanups and fixes

* tag 'x86-core-2024-03-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
  x86/idle: Select idle routine only once
  x86/idle: Let prefer_mwait_c1_over_halt() return bool
  x86/idle: Cleanup idle_setup()
  x86/idle: Clean up idle selection
  x86/idle: Sanitize X86_BUG_AMD_E400 handling
  sched/idle: Conditionally handle tick broadcast in default_idle_call()
  x86: Increase brk randomness entropy for 64-bit systems
  x86/vdso: Move vDSO to mmap region
  x86/vdso/kbuild: Group non-standard build attributes and primary object file rules together
  x86/vdso: Fix rethunk patching for vdso-image-{32,64}.o
  x86/retpoline: Ensure default return thunk isn't used at runtime
  x86/vdso: Use CONFIG_COMPAT_32 to specify vdso32
  x86/vdso: Use $(addprefix ) instead of $(foreach )
  x86/vdso: Simplify obj-y addition
  x86/vdso: Consolidate targets and clean-files
  x86/bugs: Rename CONFIG_RETHUNK              => CONFIG_MITIGATION_RETHUNK
  x86/bugs: Rename CONFIG_CPU_SRSO             => CONFIG_MITIGATION_SRSO
  x86/bugs: Rename CONFIG_CPU_IBRS_ENTRY       => CONFIG_MITIGATION_IBRS_ENTRY
  x86/bugs: Rename CONFIG_CPU_UNRET_ENTRY      => CONFIG_MITIGATION_UNRET_ENTRY
  x86/bugs: Rename CONFIG_SLS                  => CONFIG_MITIGATION_SLS
  ...
 2024-03-11 19:53:15 -07:00
Jakub Kicinski
5f20e6ab1f for-netdev 
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Alexei Starovoitov says:

====================
pull-request: bpf-next 2024-03-11

We've added 59 non-merge commits during the last 9 day(s) which contain
a total of 88 files changed, 4181 insertions(+), 590 deletions(-).

The main changes are:

1) Enforce VM_IOREMAP flag and range in ioremap_page_range and introduce
   VM_SPARSE kind and vm_area_[un]map_pages to be used in bpf_arena,
   from Alexei.

2) Introduce bpf_arena which is sparse shared memory region between bpf
   program and user space where structures inside the arena can have
   pointers to other areas of the arena, and pointers work seamlessly for
   both user-space programs and bpf programs, from Alexei and Andrii.

3) Introduce may_goto instruction that is a contract between the verifier
   and the program. The verifier allows the program to loop assuming it's
   behaving well, but reserves the right to terminate it, from Alexei.

4) Use IETF format for field definitions in the BPF standard
   document, from Dave.

5) Extend struct_ops libbpf APIs to allow specify version suffixes for
   stuct_ops map types, share the same BPF program between several map
   definitions, and other improvements, from Eduard.

6) Enable struct_ops support for more than one page in trampolines,
   from Kui-Feng.

7) Support kCFI + BPF on riscv64, from Puranjay.

8) Use bpf_prog_pack for arm64 bpf trampoline, from Puranjay.

9) Fix roundup_pow_of_two undefined behavior on 32-bit archs, from Toke.
====================

Link: https://lore.kernel.org/r/20240312003646.8692-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2024-03-11 18:06:04 -07:00
Andrii Nakryiko
66c8473135 bpf: move sleepable flag from bpf_prog_aux to bpf_prog 
prog->aux->sleepable is checked very frequently as part of (some) BPF
program run hot paths. So this extra aux indirection seems wasteful and
on busy systems might cause unnecessary memory cache misses.

Let's move sleepable flag into prog itself to eliminate unnecessary
pointer dereference.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Message-ID: <20240309004739.2961431-1-andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
 2024-03-11 16:41:25 -07:00
Linus Torvalds
fa4b851b4a Tracing fixes for v6.8-rc7: 
- Do not allow large strings (> 4096) as single write to trace_marker
 
   The size of a string written into trace_marker was determined by
   the size of the sub-buffer in the ring buffer. That size is
   dependent on the PAGE_SIZE of the architecture as it can be mapped
   into user space. But on PowerPC, where PAGE_SIZE is 64K, that made
   the limit of the string of writing into trace_marker 64K.
 
   One of the selftests looks at the size of the ring buffer sub-buffers
   and writes that plus more into the trace_marker. The write will take
   what it can and report back what it consumed so that the user space
   application (like echo) will write the rest of the string. The string
   is stored in the ring buffer and can be read via the "trace" or
   "trace_pipe" files.
 
   The reading of the ring buffer uses vsnprintf(), which uses a precision
   "%.*s" to make sure it only reads what is stored in the buffer, as
   a bug could cause the string to be non terminated.
 
   With the combination of the precision change and the PAGE_SIZE of 64K
   allowing huge strings to be added into the ring buffer, plus the test
   that would actually stress that limit, a bug was reported that
   the precision used was too big for "%.*s" as the string was close to
   64K in size and the max precision of vsnprintf is 32K.
 
   Linus suggested not to have that precision as it could hide a bug
   if the string was again stored without a nul byte.
 
   Another issue that was brought up is that the trace_seq buffer is
   also based on PAGE_SIZE even though it is not tied to the architecture
   limit like the ring buffer sub-buffer is. Having it be 64K * 2 is
   simply just too big and wasting memory on systems with 64K page sizes.
   It is now hardcoded to 8K which is what all other architectures with
   4K PAGE_SIZE has.
 
   Finally, the write to trace_marker is now limited to 4K as there is no
   reason to write larger strings into trace_marker.
 
 - ring_buffer_wait() should not loop.
   The ring_buffer_wait() does not have the full context (yet) on if it
   should loop or not. Just exit the loop as soon as its woken up and
   let the callers decide to loop or not (they already do, so it's a bit
   redundant).
 
 - Fix shortest_full field to be the smallest amount in the ring buffer that
   a waiter is waiting for. The "shortest_full" field is updated when a new
   waiter comes in and wants to wait for a smaller amount of data in the
   ring buffer than other waiters. But after all waiters are woken up, it's
   not reset, so if another waiter comes in wanting to wait for more data,
   it will be woken up when the ring buffer has a smaller amount from what
   the previous waiters were waiting for.
 
 - The wake up all waiters on close is incorrectly called frome .release()
   and not from .flush() so it will never wake up any waiters as the
   .release() will not get called until all .read() calls are finished. And the
   wakeup is for the waiters in those .read() calls.
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Merge tag 'trace-ring-buffer-v6.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Do not allow large strings (> 4096) as single write to trace_marker

   The size of a string written into trace_marker was determined by the
   size of the sub-buffer in the ring buffer. That size is dependent on
   the PAGE_SIZE of the architecture as it can be mapped into user
   space. But on PowerPC, where PAGE_SIZE is 64K, that made the limit of
   the string of writing into trace_marker 64K.

   One of the selftests looks at the size of the ring buffer sub-buffers
   and writes that plus more into the trace_marker. The write will take
   what it can and report back what it consumed so that the user space
   application (like echo) will write the rest of the string. The string
   is stored in the ring buffer and can be read via the "trace" or
   "trace_pipe" files.

   The reading of the ring buffer uses vsnprintf(), which uses a
   precision "%.*s" to make sure it only reads what is stored in the
   buffer, as a bug could cause the string to be non terminated.

   With the combination of the precision change and the PAGE_SIZE of 64K
   allowing huge strings to be added into the ring buffer, plus the test
   that would actually stress that limit, a bug was reported that the
   precision used was too big for "%.*s" as the string was close to 64K
   in size and the max precision of vsnprintf is 32K.

   Linus suggested not to have that precision as it could hide a bug if
   the string was again stored without a nul byte.

   Another issue that was brought up is that the trace_seq buffer is
   also based on PAGE_SIZE even though it is not tied to the
   architecture limit like the ring buffer sub-buffer is. Having it be
   64K * 2 is simply just too big and wasting memory on systems with 64K
   page sizes. It is now hardcoded to 8K which is what all other
   architectures with 4K PAGE_SIZE has.

   Finally, the write to trace_marker is now limited to 4K as there is
   no reason to write larger strings into trace_marker.

 - ring_buffer_wait() should not loop.

   The ring_buffer_wait() does not have the full context (yet) on if it
   should loop or not. Just exit the loop as soon as its woken up and
   let the callers decide to loop or not (they already do, so it's a bit
   redundant).

 - Fix shortest_full field to be the smallest amount in the ring buffer
   that a waiter is waiting for. The "shortest_full" field is updated
   when a new waiter comes in and wants to wait for a smaller amount of
   data in the ring buffer than other waiters. But after all waiters are
   woken up, it's not reset, so if another waiter comes in wanting to
   wait for more data, it will be woken up when the ring buffer has a
   smaller amount from what the previous waiters were waiting for.

 - The wake up all waiters on close is incorrectly called frome
   .release() and not from .flush() so it will never wake up any waiters
   as the .release() will not get called until all .read() calls are
   finished. And the wakeup is for the waiters in those .read() calls.

* tag 'trace-ring-buffer-v6.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Use .flush() call to wake up readers
  ring-buffer: Fix resetting of shortest_full
  ring-buffer: Fix waking up ring buffer readers
  tracing: Limit trace_marker writes to just 4K
  tracing: Limit trace_seq size to just 8K and not depend on architecture PAGE_SIZE
  tracing: Remove precision vsnprintf() check from print event
 2024-03-10 11:53:21 -07:00
Steven Rostedt (Google)
e5d7c19165 tracing: Use .flush() call to wake up readers 
The .release() function does not get called until all readers of a file
descriptor are finished.

If a thread is blocked on reading a file descriptor in ring_buffer_wait(),
and another thread closes the file descriptor, it will not wake up the
other thread as ring_buffer_wake_waiters() is called by .release(), and
that will not get called until the .read() is finished.

The issue originally showed up in trace-cmd, but the readers are actually
other processes with their own file descriptors. So calling close() would wake
up the other tasks because they are blocked on another descriptor then the
one that was closed(). But there's other wake ups that solve that issue.

When a thread is blocked on a read, it can still hang even when another
thread closed its descriptor.

This is what the .flush() callback is for. Have the .flush() wake up the
readers.

Link: https://lore.kernel.org/linux-trace-kernel/20240308202432.107909457@goodmis.org

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linke li <lilinke99@qq.com>
Cc: Rabin Vincent <rabin@rab.in>
Fixes: f3ddb74ad0 ("tracing: Wake up ring buffer waiters on closing of the file")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-10 12:27:47 -04:00
Steven Rostedt (Google)
68282dd930 ring-buffer: Fix resetting of shortest_full 
The "shortest_full" variable is used to keep track of the waiter that is
waiting for the smallest amount on the ring buffer before being woken up.
When a tasks waits on the ring buffer, it passes in a "full" value that is
a percentage. 0 means wake up on any data. 1-100 means wake up from 1% to
100% full buffer.

As all waiters are on the same wait queue, the wake up happens for the
waiter with the smallest percentage.

The problem is that the smallest_full on the cpu_buffer that stores the
smallest amount doesn't get reset when all the waiters are woken up. It
does get reset when the ring buffer is reset (echo > /sys/kernel/tracing/trace).

This means that tasks may be woken up more often then when they want to
be. Instead, have the shortest_full field get reset just before waking up
all the tasks. If the tasks wait again, they will update the shortest_full
before sleeping.

Also add locking around setting of shortest_full in the poll logic, and
change "work" to "rbwork" to match the variable name for rb_irq_work
structures that are used in other places.

Link: https://lore.kernel.org/linux-trace-kernel/20240308202431.948914369@goodmis.org

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linke li <lilinke99@qq.com>
Cc: Rabin Vincent <rabin@rab.in>
Fixes: 2c2b0a78b3 ("ring-buffer: Add percentage of ring buffer full to wake up reader")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-10 12:27:40 -04:00
Steven Rostedt (Google)
b359457368 ring-buffer: Fix waking up ring buffer readers 
A task can wait on a ring buffer for when it fills up to a specific
watermark. The writer will check the minimum watermark that waiters are
waiting for and if the ring buffer is past that, it will wake up all the
waiters.

The waiters are in a wait loop, and will first check if a signal is
pending and then check if the ring buffer is at the desired level where it
should break out of the loop.

If a file that uses a ring buffer closes, and there's threads waiting on
the ring buffer, it needs to wake up those threads. To do this, a
"wait_index" was used.

Before entering the wait loop, the waiter will read the wait_index. On
wakeup, it will check if the wait_index is different than when it entered
the loop, and will exit the loop if it is. The waker will only need to
update the wait_index before waking up the waiters.

This had a couple of bugs. One trivial one and one broken by design.

The trivial bug was that the waiter checked the wait_index after the
schedule() call. It had to be checked between the prepare_to_wait() and
the schedule() which it was not.

The main bug is that the first check to set the default wait_index will
always be outside the prepare_to_wait() and the schedule(). That's because
the ring_buffer_wait() doesn't have enough context to know if it should
break out of the loop.

The loop itself is not needed, because all the callers to the
ring_buffer_wait() also has their own loop, as the callers have a better
sense of what the context is to decide whether to break out of the loop
or not.

Just have the ring_buffer_wait() block once, and if it gets woken up, exit
the function and let the callers decide what to do next.

Link: https://lore.kernel.org/all/CAHk-=whs5MdtNjzFkTyaUy=vHi=qwWgPi0JgTe6OYUYMNSRZfg@mail.gmail.com/
Link: https://lore.kernel.org/linux-trace-kernel/20240308202431.792933613@goodmis.org

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linke li <lilinke99@qq.com>
Cc: Rabin Vincent <rabin@rab.in>
Fixes: e30f53aad2 ("tracing: Do not busy wait in buffer splice")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-10 12:24:59 -04:00
Jakub Kicinski
e3afe5dd3a Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 
Cross-merge networking fixes after downstream PR.

No conflicts.

Adjacent changes:

net/core/page_pool_user.c
  0b11b1c5c3 ("netdev: let netlink core handle -EMSGSIZE errors")
  429679dcf7 ("page_pool: fix netlink dump stop/resume")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2024-03-07 10:29:36 -08:00
Steven Rostedt (Google)
095fe48912 tracing: Limit trace_marker writes to just 4K 
Limit the max print event of trace_marker to just 4K string size. This must
also be less than the amount that can be held by a trace_seq along with
the text that is before the output (like the task name, PID, CPU, state,
etc). As trace_seq is made to handle large events (some greater than 4K).
Make the max size of a trace_marker write event be 4K which is guaranteed
to fit in the trace_seq buffer.

Link: https://lore.kernel.org/linux-trace-kernel/20240304223433.4ba47dff@gandalf.local.home

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-06 13:27:26 -05:00
Steven Rostedt (Google)
5efd3e2aef tracing: Remove precision vsnprintf() check from print event 
This reverts 60be76eeab ("tracing: Add size check when printing
trace_marker output"). The only reason the precision check was added
was because of a bug that miscalculated the write size of the string into
the ring buffer and it truncated it removing the terminating nul byte. On
reading the trace it crashed the kernel. But this was due to the bug in
the code that happened during development and should never happen in
practice. If anything, the precision can hide bugs where the string in the
ring buffer isn't nul terminated and it will not be checked.

Link: https://lore.kernel.org/all/C7E7AF1A-D30F-4D18-B8E5-AF1EF58004F5@linux.ibm.com/
Link: https://lore.kernel.org/linux-trace-kernel/20240227125706.04279ac2@gandalf.local.home
Link: https://lore.kernel.org/all/20240302111244.3a1674be@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20240304174341.2a561d9f@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: 60be76eeab ("tracing: Add size check when printing trace_marker output")
Reported-by: Sachin Sant <sachinp@linux.ibm.com>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-06 13:26:26 -05:00
Masami Hiramatsu (Google)
25f00e40ce tracing/probes: Support $argN in return probe (kprobe and fprobe) 
Support accessing $argN in the return probe events. This will help users to
record entry data in function return (exit) event for simplfing the function
entry/exit information in one event, and record the result values (e.g.
allocated object/initialized object) at function exit.

For example, if we have a function `int init_foo(struct foo *obj, int param)`
sometimes we want to check how `obj` is initialized. In such case, we can
define a new return event like below;

 # echo 'r init_foo retval=$retval param=$arg2 field1=+0($arg1)' >> kprobe_events

Thus it records the function parameter `param` and its result `obj->field1`
(the dereference will be done in the function exit timing) value at once.

This also support fprobe, BTF args and'$arg*'. So if CONFIG_DEBUG_INFO_BTF
is enabled, we can trace both function parameters and the return value
by following command.

 # echo 'f target_function%return $arg* $retval' >> dynamic_events

Link: https://lore.kernel.org/all/170952365552.229804.224112990211602895.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-03-07 00:27:34 +09:00
Masami Hiramatsu (Google)
c18f9eabee tracing: Remove redundant #else block for BTF args from README 
Remove redundant #else block for BTF args from README message.
This is a cleanup, so no change on the message.

Link: https://lore.kernel.org/all/170952364558.229804.17285528811097152410.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-07 00:27:25 +09:00
Masami Hiramatsu (Google)
035ba76014 tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init 
Instead of incrementing the trace_probe::nr_args, init it at
trace_probe_init(). Without this change, there is no way to get the number
of trace_probe arguments while parsing it.
This is a cleanup, so the behavior is not changed.

Link: https://lore.kernel.org/all/170952363585.229804.13060759900346411951.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-03-07 00:27:15 +09:00
Masami Hiramatsu (Google)
032330abd0 tracing/probes: Cleanup probe argument parser 
Cleanup traceprobe_parse_probe_arg_body() to split out the
type parser and post-processing part of fetch_insn.
This makes no functional change.

Link: https://lore.kernel.org/all/170952362603.229804.9942703761682605372.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-07 00:27:06 +09:00
Masami Hiramatsu (Google)
7e37b6bc3c tracing/fprobe-event: cleanup: Fix a wrong comment in fprobe event 
Despite the fprobe event,  "Kretprobe" was commented. So fix it.

Link: https://lore.kernel.org/all/170952361630.229804.10832200172327797860.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-03-07 00:26:57 +09:00
Jakub Kicinski
4b2765ae41 bpf-next-for-netdev 
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-02-29

We've added 119 non-merge commits during the last 32 day(s) which contain
a total of 150 files changed, 3589 insertions(+), 995 deletions(-).

The main changes are:

1) Extend the BPF verifier to enable static subprog calls in spin lock
   critical sections, from Kumar Kartikeya Dwivedi.

2) Fix confusing and incorrect inference of PTR_TO_CTX argument type
   in BPF global subprogs, from Andrii Nakryiko.

3) Larger batch of riscv BPF JIT improvements and enabling inlining
   of the bpf_kptr_xchg() for RV64, from Pu Lehui.

4) Allow skeleton users to change the values of the fields in struct_ops
   maps at runtime, from Kui-Feng Lee.

5) Extend the verifier's capabilities of tracking scalars when they
   are spilled to stack, especially when the spill or fill is narrowing,
   from Maxim Mikityanskiy & Eduard Zingerman.

6) Various BPF selftest improvements to fix errors under gcc BPF backend,
   from Jose E. Marchesi.

7) Avoid module loading failure when the module trying to register
   a struct_ops has its BTF section stripped, from Geliang Tang.

8) Annotate all kfuncs in .BTF_ids section which eventually allows
   for automatic kfunc prototype generation from bpftool, from Daniel Xu.

9) Several updates to the instruction-set.rst IETF standardization
   document, from Dave Thaler.

10) Shrink the size of struct bpf_map resp. bpf_array,
    from Alexei Starovoitov.

11) Initial small subset of BPF verifier prepwork for sleepable bpf_timer,
    from Benjamin Tissoires.

12) Fix bpftool to be more portable to musl libc by using POSIX's
    basename(), from Arnaldo Carvalho de Melo.

13) Add libbpf support to gcc in CORE macro definitions,
    from Cupertino Miranda.

14) Remove a duplicate type check in perf_event_bpf_event,
    from Florian Lehner.

15) Fix bpf_spin_{un,}lock BPF helpers to actually annotate them
    with notrace correctly, from Yonghong Song.

16) Replace the deprecated bpf_lpm_trie_key 0-length array with flexible
    array to fix build warnings, from Kees Cook.

17) Fix resolve_btfids cross-compilation to non host-native endianness,
    from Viktor Malik.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (119 commits)
  selftests/bpf: Test if shadow types work correctly.
  bpftool: Add an example for struct_ops map and shadow type.
  bpftool: Generated shadow variables for struct_ops maps.
  libbpf: Convert st_ops->data to shadow type.
  libbpf: Set btf_value_type_id of struct bpf_map for struct_ops.
  bpf: Replace bpf_lpm_trie_key 0-length array with flexible array
  bpf, arm64: use bpf_prog_pack for memory management
  arm64: patching: implement text_poke API
  bpf, arm64: support exceptions
  arm64: stacktrace: Implement arch_bpf_stack_walk() for the BPF JIT
  bpf: add is_async_callback_calling_insn() helper
  bpf: introduce in_sleepable() helper
  bpf: allow more maps in sleepable bpf programs
  selftests/bpf: Test case for lacking CFI stub functions.
  bpf: Check cfi_stubs before registering a struct_ops type.
  bpf: Clarify batch lookup/lookup_and_delete semantics
  bpf, docs: specify which BPF_ABS and BPF_IND fields were zero
  bpf, docs: Fix typos in instruction-set.rst
  selftests/bpf: update tcp_custom_syncookie to use scalar packet offset
  bpf: Shrink size of struct bpf_map/bpf_array.
  ...
====================

Link: https://lore.kernel.org/r/20240301001625.8800-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2024-03-02 20:50:59 -08:00
Linus Torvalds
161671a6eb Probes fixes for v6.8-rc5: 
- fprobe: Fix to allocate entry_data_size buffer for each rethook
     instance. This fixes a buffer overrun bug (which leads a kernel
     crash) when fprobe user uses its entry_data in the entry_handler.
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Merge tag 'probes-fixes-v6.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull fprobe fix from Masami Hiramatsu:

 - allocate entry_data_size buffer for each rethook instance.

   This fixes a buffer overrun bug (which leads a kernel crash)
   when fprobe user uses its entry_data in the entry_handler.

* tag 'probes-fixes-v6.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  fprobe: Fix to allocate entry_data_size buffer with rethook instances
 2024-03-01 11:17:23 -08:00
Masami Hiramatsu (Google)
6572786006 fprobe: Fix to allocate entry_data_size buffer with rethook instances 
Fix to allocate fprobe::entry_data_size buffer with rethook instances.
If fprobe doesn't allocate entry_data_size buffer for each rethook instance,
fprobe entry handler can cause a buffer overrun when storing entry data in
entry handler.

Link: https://lore.kernel.org/all/170920576727.107552.638161246679734051.stgit@devnote2/

Reported-by: Jiri Olsa <olsajiri@gmail.com>
Closes: https://lore.kernel.org/all/Zd9eBn2FTQzYyg7L@krava/
Fixes: 4bbd934556 ("kprobes: kretprobe scalability improvement")
Cc: stable@vger.kernel.org
Tested-by: Jiri Olsa <olsajiri@gmail.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-03-01 09:18:24 +09:00
Jakub Kicinski
fecc51559a Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 
Cross-merge networking fixes after downstream PR.

Conflicts:

net/ipv4/udp.c
  f796feabb9 ("udp: add local "peek offset enabled" flag")
  56667da739 ("net: implement lockless setsockopt(SO_PEEK_OFF)")

Adjacent changes:

net/unix/garbage.c
  aa82ac51d6 ("af_unix: Drop oob_skb ref before purging queue in GC.")
  11498715f2 ("af_unix: Remove io_uring code for GC.")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2024-02-22 15:29:26 -08:00
Steven Rostedt (Google)
e78fb4eac8 ring-buffer: Do not let subbuf be bigger than write mask 
The data on the subbuffer is measured by a write variable that also
contains status flags. The counter is just 20 bits in length. If the
subbuffer is bigger than then counter, it will fail.

Make sure that the subbuffer can not be set to greater than the counter
that keeps track of the data on the subbuffer.

Link: https://lore.kernel.org/linux-trace-kernel/20240220095112.77e9cb81@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 2808e31ec1 ("ring-buffer: Add interface for configuring trace sub buffer size")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-02-21 09:15:23 -05:00
Linus Torvalds
ad645dea35 Probes fixes for v6.8-rc4: 
- tracing/probes: Fix BTF structure member finder to find the members
     which are placed after any anonymous union member correctly.
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Merge tag 'probes-fixes-v6.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes fix from Masami Hiramatsu:

 - tracing/probes: Fix BTF structure member finder to find the members
   which are placed after any anonymous union member correctly.

* tag 'probes-fixes-v6.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/probes: Fix to search structure fields correctly
 2024-02-17 07:59:47 -08:00
Masami Hiramatsu (Google)
9704669c38 tracing/probes: Fix to search structure fields correctly 
Fix to search a field from the structure which has anonymous union
correctly.
Since the reference `type` pointer was updated in the loop, the search
loop suddenly aborted where it hits an anonymous union. Thus it can not
find the field after the anonymous union. This avoids updating the
cursor `type` pointer in the loop.

Link: https://lore.kernel.org/all/170791694361.389532.10047514554799419688.stgit@devnote2/

Fixes: 302db0f5b3 ("tracing/probes: Add a function to search a member of a struct/union")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-02-17 21:25:42 +09:00
Linus Torvalds
4b6f7c624e Tracing fixes for v6.8: 
- Fix the #ifndef that didn't have CONFIG_ on HAVE_DYNAMIC_FTRACE_WITH_REGS
   The fix to have dynamic trampolines work with x86 broke arm64 as
   the config used in the #ifdef was HAVE_DYNAMIC_FTRACE_WITH_REGS and not
   CONFIG_HAVE_DYNAMIC_FTRACE_WITH_REGS which removed the fix that the
   previous fix was to fix.
 
 - Fix tracing_on state
   The code to test if "tracing_on" is set used ring_buffer_record_is_on()
   which returns false if the ring buffer isn't able to be written to.
   But the ring buffer disable has several bits that disable it.
   One is internal disabling which is used for resizing and other
   modifications of the ring buffer. But the "tracing_on" user space
   visible flag should only report if tracing is actually on and not
   internally disabled, as this can cause confusion as writing "1"
   when it is disabled will not enable it.
 
   Instead use ring_buffer_record_is_set_on() which shows the user space
   visible settings.
 
 - Fix a false positive kmemleak on saved cmdlines
   Now that the saved_cmdlines structure is allocated via alloc_page()
   and not via kmalloc() it has become invisible to kmemleak.
   The allocation done to one of its pointers was flagged as a
   dangling allocation leak. Make kmemleak aware of this allocation
   and free.
 
 - Fix synthetic event dynamic strings.
   A update that cleaned up the synthetic event code removed the
   return value of trace_string(), and had it return zero instead
   of the length, causing dynamic strings in the synthetic event
   to always have zero size.
 
 - Clean up documentation and header files for seq_buf
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Merge tag 'trace-v6.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Fix the #ifndef that didn't have the 'CONFIG_' prefix on
   HAVE_DYNAMIC_FTRACE_WITH_REGS

   The fix to have dynamic trampolines work with x86 broke arm64 as the
   config used in the #ifdef was HAVE_DYNAMIC_FTRACE_WITH_REGS and not
   CONFIG_HAVE_DYNAMIC_FTRACE_WITH_REGS which removed the fix that the
   previous fix was to fix.

 - Fix tracing_on state

   The code to test if "tracing_on" is set incorrectly used
   ring_buffer_record_is_on() which returns false if the ring buffer
   isn't able to be written to.

   But the ring buffer disable has several bits that disable it. One is
   internal disabling which is used for resizing and other modifications
   of the ring buffer. But the "tracing_on" user space visible flag
   should only report if tracing is actually on and not internally
   disabled, as this can cause confusion as writing "1" when it is
   disabled will not enable it.

   Instead use ring_buffer_record_is_set_on() which shows the user space
   visible settings.

 - Fix a false positive kmemleak on saved cmdlines

   Now that the saved_cmdlines structure is allocated via alloc_page()
   and not via kmalloc() it has become invisible to kmemleak. The
   allocation done to one of its pointers was flagged as a dangling
   allocation leak. Make kmemleak aware of this allocation and free.

 - Fix synthetic event dynamic strings

   An update that cleaned up the synthetic event code removed the return
   value of trace_string(), and had it return zero instead of the
   length, causing dynamic strings in the synthetic event to always have
   zero size.

 - Clean up documentation and header files for seq_buf

* tag 'trace-v6.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  seq_buf: Fix kernel documentation
  seq_buf: Don't use "proxy" headers
  tracing/synthetic: Fix trace_string() return value
  tracing: Inform kmemleak of saved_cmdlines allocation
  tracing: Use ring_buffer_record_is_set_on() in tracer_tracing_is_on()
  tracing: Fix HAVE_DYNAMIC_FTRACE_WITH_REGS ifdef
 2024-02-16 10:33:51 -08:00
Jakub Kicinski
73be9a3aab Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 
Cross-merge networking fixes after downstream PR.

No conflicts.

Adjacent changes:

net/core/dev.c
  9f30831390 ("net: add rcu safety to rtnl_prop_list_size()")
  723de3ebef ("net: free altname using an RCU callback")

net/unix/garbage.c
  11498715f2 ("af_unix: Remove io_uring code for GC.")
  25236c91b5 ("af_unix: Fix task hung while purging oob_skb in GC.")

drivers/net/ethernet/renesas/ravb_main.c
  ed4adc0720 ("net: ravb: Count packets instead of descriptors in GbEth RX path"
)
  c2da940857 ("ravb: Add Rx checksum offload support for GbEth")

net/mptcp/protocol.c
  bdd70eb689 ("mptcp: drop the push_pending field")
  28e5c13805 ("mptcp: annotate lockless accesses around read-mostly fields")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2024-02-15 16:20:04 -08:00
Thorsten Blum
9b6326354c tracing/synthetic: Fix trace_string() return value 
Fix trace_string() by assigning the string length to the return variable
which got lost in commit ddeea494a1 ("tracing/synthetic: Use union
instead of casts") and caused trace_string() to always return 0.

Link: https://lore.kernel.org/linux-trace-kernel/20240214220555.711598-1-thorsten.blum@toblux.com

Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: ddeea494a1 ("tracing/synthetic: Use union instead of casts")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-02-15 11:40:01 -05:00
Steven Rostedt (Google)
2394ac4145 tracing: Inform kmemleak of saved_cmdlines allocation 
The allocation of the struct saved_cmdlines_buffer structure changed from:

        s = kmalloc(sizeof(*s), GFP_KERNEL);
	s->saved_cmdlines = kmalloc_array(TASK_COMM_LEN, val, GFP_KERNEL);

to:

	orig_size = sizeof(*s) + val * TASK_COMM_LEN;
	order = get_order(orig_size);
	size = 1 << (order + PAGE_SHIFT);
	page = alloc_pages(GFP_KERNEL, order);
	if (!page)
		return NULL;

	s = page_address(page);
	memset(s, 0, sizeof(*s));

	s->saved_cmdlines = kmalloc_array(TASK_COMM_LEN, val, GFP_KERNEL);

Where that s->saved_cmdlines allocation looks to be a dangling allocation
to kmemleak. That's because kmemleak only keeps track of kmalloc()
allocations. For allocations that use page_alloc() directly, the kmemleak
needs to be explicitly informed about it.

Add kmemleak_alloc() and kmemleak_free() around the page allocation so
that it doesn't give the following false positive:

unreferenced object 0xffff8881010c8000 (size 32760):
  comm "swapper", pid 0, jiffies 4294667296
  hex dump (first 32 bytes):
    ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff  ................
    ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff  ................
  backtrace (crc ae6ec1b9):
    [<ffffffff86722405>] kmemleak_alloc+0x45/0x80
    [<ffffffff8414028d>] __kmalloc_large_node+0x10d/0x190
    [<ffffffff84146ab1>] __kmalloc+0x3b1/0x4c0
    [<ffffffff83ed7103>] allocate_cmdlines_buffer+0x113/0x230
    [<ffffffff88649c34>] tracer_alloc_buffers.isra.0+0x124/0x460
    [<ffffffff8864a174>] early_trace_init+0x14/0xa0
    [<ffffffff885dd5ae>] start_kernel+0x12e/0x3c0
    [<ffffffff885f5758>] x86_64_start_reservations+0x18/0x30
    [<ffffffff885f582b>] x86_64_start_kernel+0x7b/0x80
    [<ffffffff83a001c3>] secondary_startup_64_no_verify+0x15e/0x16b

Link: https://lore.kernel.org/linux-trace-kernel/87r0hfnr9r.fsf@kernel.org/
Link: https://lore.kernel.org/linux-trace-kernel/20240214112046.09a322d6@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Fixes: 44dc5c41b5 ("tracing: Fix wasted memory in saved_cmdlines logic")
Reported-by: Kalle Valo <kvalo@kernel.org>
Tested-by: Kalle Valo <kvalo@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-02-14 12:36:34 -05:00
Ingo Molnar
4589f199eb Merge branch 'x86/bugs' into x86/core, to pick up pending changes before dependent patches 
Merge in pending alternatives patching infrastructure changes, before
applying more patches.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
 2024-02-14 10:49:37 +01:00
Sven Schnelle
a6eaa24f1c tracing: Use ring_buffer_record_is_set_on() in tracer_tracing_is_on() 
tracer_tracing_is_on() checks whether record_disabled is not zero. This
checks both the record_disabled counter and the RB_BUFFER_OFF flag.
Reading the source it looks like this function should only check for
the RB_BUFFER_OFF flag. Therefore use ring_buffer_record_is_set_on().
This fixes spurious fails in the 'test for function traceon/off triggers'
test from the ftrace testsuite when the system is under load.

Link: https://lore.kernel.org/linux-trace-kernel/20240205065340.2848065-1-svens@linux.ibm.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Tested-By: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-02-13 12:04:17 -05:00
Petr Pavlu
bdbddb109c tracing: Fix HAVE_DYNAMIC_FTRACE_WITH_REGS ifdef 
Commit a8b9cf62ad ("ftrace: Fix DIRECT_CALLS to use SAVE_REGS by
default") attempted to fix an issue with direct trampolines on x86, see
its description for details. However, it wrongly referenced the
HAVE_DYNAMIC_FTRACE_WITH_REGS config option and the problem is still
present.

Add the missing "CONFIG_" prefix for the logic to work as intended.

Link: https://lore.kernel.org/linux-trace-kernel/20240213132434.22537-1-petr.pavlu@suse.com

Fixes: a8b9cf62ad ("ftrace: Fix DIRECT_CALLS to use SAVE_REGS by default")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-02-13 11:56:49 -05:00
Linus Torvalds
ca8a66738a Tracing fixes for v6.8-rc3: 
- Fix broken direct trampolines being called when another callback is
   attached the same function. ARM 64 does not support FTRACE_WITH_REGS, and
   when it added direct trampoline calls from ftrace, it removed the
   "WITH_REGS" flag from the ftrace_ops for direct trampolines. This broke
   x86 as x86 requires direct trampolines to have WITH_REGS. This wasn't
   noticed because direct trampolines work as long as the function it is
   attached to is not shared with other callbacks (like the function tracer).
   When there's other callbacks, a helper trampoline is called, to call all
   the non direct callbacks and when it returns, the direct trampoline is
   called. For x86, the direct trampoline sets a flag in the regs field to
   tell the x86 specific code to call the direct trampoline. But this only
   works if the ftrace_ops had WITH_REGS set. ARM does things differently
   that does not require this. For now, set WITH_REGS if the arch supports
   WITH_REGS (which ARM does not), and this makes it work for both ARM64 and
   x86.
 
 - Fix wasted memory in the saved_cmdlines logic.
 
   The saved_cmdlines is a cache that maps PIDs to COMMs that tracing can
   use. Most trace events only save the PID in the event. The saved_cmdlines
   file lists PIDs to COMMs so that the tracing tools can show an actual name
   and not just a PID for each event. There's an array of PIDs that map to a
   small set of saved COMM strings. The array is set to PID_MAX_DEFAULT which
   is usually set to 32768. When a PID comes in, it will add itself to this
   array along with the index into the COMM array (note if the system allows
   more than PID_MAX_DEFAULT, this cache is similar to cache lines as an
   update of a PID that has the same PID_MAX_DEFAULT bits set will flush out
   another task with the same matching bits set).
 
   A while ago, the size of this cache was changed to be dynamic and the
   array was moved into a structure and created with kmalloc(). But this
   new structure had the size of 131104 bytes, or 0x20020 in hex. As kmalloc
   allocates in powers of two, it was actually allocating 0x40000 bytes
   (262144) leaving 131040 bytes of wasted memory. The last element of this
   structure was a pointer to the COMM string array which defaulted to just
   saving 128 COMMs.
 
   By changing the last field of this structure to a variable length string,
   and just having it round up to fill the allocated memory, the default
   size of the saved COMM cache is now 8190. This not only uses the wasted
   space, but actually saves space by removing the extra allocation for the
   COMM names.
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Merge tag 'trace-v6.8-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Fix broken direct trampolines being called when another callback is
   attached the same function.

   ARM 64 does not support FTRACE_WITH_REGS, and when it added direct
   trampoline calls from ftrace, it removed the "WITH_REGS" flag from
   the ftrace_ops for direct trampolines. This broke x86 as x86 requires
   direct trampolines to have WITH_REGS.

   This wasn't noticed because direct trampolines work as long as the
   function it is attached to is not shared with other callbacks (like
   the function tracer). When there are other callbacks, a helper
   trampoline is called, to call all the non direct callbacks and when
   it returns, the direct trampoline is called.

   For x86, the direct trampoline sets a flag in the regs field to tell
   the x86 specific code to call the direct trampoline. But this only
   works if the ftrace_ops had WITH_REGS set. ARM does things
   differently that does not require this. For now, set WITH_REGS if the
   arch supports WITH_REGS (which ARM does not), and this makes it work
   for both ARM64 and x86.

 - Fix wasted memory in the saved_cmdlines logic.

   The saved_cmdlines is a cache that maps PIDs to COMMs that tracing
   can use. Most trace events only save the PID in the event. The
   saved_cmdlines file lists PIDs to COMMs so that the tracing tools can
   show an actual name and not just a PID for each event. There's an
   array of PIDs that map to a small set of saved COMM strings. The
   array is set to PID_MAX_DEFAULT which is usually set to 32768. When a
   PID comes in, it will add itself to this array along with the index
   into the COMM array (note if the system allows more than
   PID_MAX_DEFAULT, this cache is similar to cache lines as an update of
   a PID that has the same PID_MAX_DEFAULT bits set will flush out
   another task with the same matching bits set).

   A while ago, the size of this cache was changed to be dynamic and the
   array was moved into a structure and created with kmalloc(). But this
   new structure had the size of 131104 bytes, or 0x20020 in hex. As
   kmalloc allocates in powers of two, it was actually allocating
   0x40000 bytes (262144) leaving 131040 bytes of wasted memory. The
   last element of this structure was a pointer to the COMM string array
   which defaulted to just saving 128 COMMs.

   By changing the last field of this structure to a variable length
   string, and just having it round up to fill the allocated memory, the
   default size of the saved COMM cache is now 8190. This not only uses
   the wasted space, but actually saves space by removing the extra
   allocation for the COMM names.

* tag 'trace-v6.8-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Fix wasted memory in saved_cmdlines logic
  ftrace: Fix DIRECT_CALLS to use SAVE_REGS by default
 2024-02-09 11:13:19 -08:00
Steven Rostedt (Google)
44dc5c41b5 tracing: Fix wasted memory in saved_cmdlines logic 
While looking at improving the saved_cmdlines cache I found a huge amount
of wasted memory that should be used for the cmdlines.

The tracing data saves pids during the trace. At sched switch, if a trace
occurred, it will save the comm of the task that did the trace. This is
saved in a "cache" that maps pids to comms and exposed to user space via
the /sys/kernel/tracing/saved_cmdlines file. Currently it only caches by
default 128 comms.

The structure that uses this creates an array to store the pids using
PID_MAX_DEFAULT (which is usually set to 32768). This causes the structure
to be of the size of 131104 bytes on 64 bit machines.

In hex: 131104 = 0x20020, and since the kernel allocates generic memory in
powers of two, the kernel would allocate 0x40000 or 262144 bytes to store
this structure. That leaves 131040 bytes of wasted space.

Worse, the structure points to an allocated array to store the comm names,
which is 16 bytes times the amount of names to save (currently 128), which
is 2048 bytes. Instead of allocating a separate array, make the structure
end with a variable length string and use the extra space for that.

This is similar to a recommendation that Linus had made about eventfs_inode names:

  https://lore.kernel.org/all/20240130190355.11486-5-torvalds@linux-foundation.org/

Instead of allocating a separate string array to hold the saved comms,
have the structure end with: char saved_cmdlines[]; and round up to the
next power of two over sizeof(struct saved_cmdline_buffers) + num_cmdlines * TASK_COMM_LEN
It will use this extra space for the saved_cmdline portion.

Now, instead of saving only 128 comms by default, by using this wasted
space at the end of the structure it can save over 8000 comms and even
saves space by removing the need for allocating the other array.

Link: https://lore.kernel.org/linux-trace-kernel/20240209063622.1f7b6d5f@rorschach.local.home

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Mete Durlu <meted@linux.ibm.com>
Fixes: 939c7a4f04 ("tracing: Introduce saved_cmdlines_size file")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-02-09 06:43:21 -05:00
Masami Hiramatsu (Google)
a8b9cf62ad ftrace: Fix DIRECT_CALLS to use SAVE_REGS by default 
The commit 60c8971899 ("ftrace: Make DIRECT_CALLS work WITH_ARGS
and !WITH_REGS") changed DIRECT_CALLS to use SAVE_ARGS when there
are multiple ftrace_ops at the same function, but since the x86 only
support to jump to direct_call from ftrace_regs_caller, when we set
the function tracer on the same target function on x86, ftrace-direct
does not work as below (this actually works on arm64.)

At first, insmod ftrace-direct.ko to put a direct_call on
'wake_up_process()'.

 # insmod kernel/samples/ftrace/ftrace-direct.ko
 # less trace
...
          <idle>-0       [006] ..s1.   564.686958: my_direct_func: waking up rcu_preempt-17
          <idle>-0       [007] ..s1.   564.687836: my_direct_func: waking up kcompactd0-63
          <idle>-0       [006] ..s1.   564.690926: my_direct_func: waking up rcu_preempt-17
          <idle>-0       [006] ..s1.   564.696872: my_direct_func: waking up rcu_preempt-17
          <idle>-0       [007] ..s1.   565.191982: my_direct_func: waking up kcompactd0-63

Setup a function filter to the 'wake_up_process' too, and enable it.

 # cd /sys/kernel/tracing/
 # echo wake_up_process > set_ftrace_filter
 # echo function > current_tracer
 # less trace
...
          <idle>-0       [006] ..s3.   686.180972: wake_up_process <-call_timer_fn
          <idle>-0       [006] ..s3.   686.186919: wake_up_process <-call_timer_fn
          <idle>-0       [002] ..s3.   686.264049: wake_up_process <-call_timer_fn
          <idle>-0       [002] d.h6.   686.515216: wake_up_process <-kick_pool
          <idle>-0       [002] d.h6.   686.691386: wake_up_process <-kick_pool

Then, only function tracer is shown on x86.
But if you enable 'kprobe on ftrace' event (which uses SAVE_REGS flag)
on the same function, it is shown again.

 # echo 'p wake_up_process' >> dynamic_events
 # echo 1 > events/kprobes/p_wake_up_process_0/enable
 # echo > trace
 # less trace
...
          <idle>-0       [006] ..s2.  2710.345919: p_wake_up_process_0: (wake_up_process+0x4/0x20)
          <idle>-0       [006] ..s3.  2710.345923: wake_up_process <-call_timer_fn
          <idle>-0       [006] ..s1.  2710.345928: my_direct_func: waking up rcu_preempt-17
          <idle>-0       [006] ..s2.  2710.349931: p_wake_up_process_0: (wake_up_process+0x4/0x20)
          <idle>-0       [006] ..s3.  2710.349934: wake_up_process <-call_timer_fn
          <idle>-0       [006] ..s1.  2710.349937: my_direct_func: waking up rcu_preempt-17

To fix this issue, use SAVE_REGS flag for multiple ftrace_ops flag of
direct_call by default.

Link: https://lore.kernel.org/linux-trace-kernel/170484558617.178953.1590516949390270842.stgit@devnote2

Fixes: 60c8971899 ("ftrace: Make DIRECT_CALLS work WITH_ARGS and !WITH_REGS")
Cc: stable@vger.kernel.org
Cc: Florent Revest <revest@chromium.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-02-09 04:58:22 -05:00
Jakub Kicinski
3be042cf46 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 
Cross-merge networking fixes after downstream PR.

No conflicts.

Adjacent changes:

drivers/net/ethernet/stmicro/stmmac/common.h
  38cc3c6dcc ("net: stmmac: protect updates of 64-bit statistics counters")
  fd5a6a7131 ("net: stmmac: est: Per Tx-queue error count for HLBF")
  c5c3e1bfc9 ("net: stmmac: Offload queueMaxSDU from tc-taprio")

drivers/net/wireless/microchip/wilc1000/netdev.c
  c901388028 ("wifi: fill in MODULE_DESCRIPTION()s for wilc1000")
  328efda22a ("wifi: wilc1000: do not realloc workqueue everytime an interface is added")

net/unix/garbage.c
  11498715f2 ("af_unix: Remove io_uring code for GC.")
  1279f9d9de ("af_unix: Call kfree_skb() for dead unix_(sk)->oob_skb in GC.")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2024-02-08 15:30:33 -08:00
Masami Hiramatsu (Google)
9a571c1e27 tracing/probes: Fix to set arg size and fmt after setting type from BTF 
Since the BTF type setting updates probe_arg::type, the type size
calculation and setting print-fmt should be done after that.
Without this fix, the argument size and print-fmt can be wrong.

Link: https://lore.kernel.org/all/170602218196.215583.6417859469540955777.stgit@devnote2/

Fixes: b576e09701 ("tracing/probes: Support function parameters if BTF is available")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-02-08 23:26:25 +09:00
Masami Hiramatsu (Google)
8c427cc2fa tracing/probes: Fix to show a parse error for bad type for $comm 
Fix to show a parse error for bad type (non-string) for $comm/$COMM and
immediate-string. With this fix, error_log file shows appropriate error
message as below.

 /sys/kernel/tracing # echo 'p vfs_read $comm:u32' >> kprobe_events
sh: write error: Invalid argument
 /sys/kernel/tracing # echo 'p vfs_read \"hoge":u32' >> kprobe_events
sh: write error: Invalid argument
 /sys/kernel/tracing # cat error_log

[   30.144183] trace_kprobe: error: $comm and immediate-string only accepts string type
  Command: p vfs_read $comm:u32
                            ^
[   62.618500] trace_kprobe: error: $comm and immediate-string only accepts string type
  Command: p vfs_read \"hoge":u32
                              ^
Link: https://lore.kernel.org/all/170602215411.215583.2238016352271091852.stgit@devnote2/

Fixes: 3dd1f7f24f ("tracing: probeevent: Fix to make the type of $comm string")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-02-08 23:26:13 +09:00
Jakub Kicinski
cf244463a2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 
Cross-merge networking fixes after downstream PR.

No conflicts or adjacent changes.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2024-02-01 15:12:37 -08:00
Daniel Bristot de Oliveira
1389358bb0 tracing/timerlat: Move hrtimer_init to timerlat_fd open() 
Currently, the timerlat's hrtimer is initialized at the first read of
timerlat_fd, and destroyed at close(). It works, but it causes an error
if the user program open() and close() the file without reading.

Here's an example:

 # echo NO_OSNOISE_WORKLOAD > /sys/kernel/debug/tracing/osnoise/options
 # echo timerlat > /sys/kernel/debug/tracing/current_tracer

 # cat <<EOF > ./timerlat_load.py
 # !/usr/bin/env python3

 timerlat_fd = open("/sys/kernel/tracing/osnoise/per_cpu/cpu0/timerlat_fd", 'r')
 timerlat_fd.close();
 EOF

 # ./taskset -c 0 ./timerlat_load.py
<BOOM>

 BUG: kernel NULL pointer dereference, address: 0000000000000010
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [#1] PREEMPT SMP NOPTI
 CPU: 1 PID: 2673 Comm: python3 Not tainted 6.6.13-200.fc39.x86_64 #1
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39 04/01/2014
 RIP: 0010:hrtimer_active+0xd/0x50
 Code: 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 48 8b 57 30 <8b> 42 10 a8 01 74 09 f3 90 8b 42 10 a8 01 75 f7 80 7f 38 00 75 1d
 RSP: 0018:ffffb031009b7e10 EFLAGS: 00010286
 RAX: 000000000002db00 RBX: ffff9118f786db08 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: ffff9117a0e64400 RDI: ffff9118f786db08
 RBP: ffff9118f786db80 R08: ffff9117a0ddd420 R09: ffff9117804d4f70
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff9118f786db08
 R13: ffff91178fdd5e20 R14: ffff9117840978c0 R15: 0000000000000000
 FS:  00007f2ffbab1740(0000) GS:ffff9118f7840000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000010 CR3: 00000001b402e000 CR4: 0000000000750ee0
 PKRU: 55555554
 Call Trace:
  <TASK>
  ? __die+0x23/0x70
  ? page_fault_oops+0x171/0x4e0
  ? srso_alias_return_thunk+0x5/0x7f
  ? avc_has_extended_perms+0x237/0x520
  ? exc_page_fault+0x7f/0x180
  ? asm_exc_page_fault+0x26/0x30
  ? hrtimer_active+0xd/0x50
  hrtimer_cancel+0x15/0x40
  timerlat_fd_release+0x48/0xe0
  __fput+0xf5/0x290
  __x64_sys_close+0x3d/0x80
  do_syscall_64+0x60/0x90
  ? srso_alias_return_thunk+0x5/0x7f
  ? __x64_sys_ioctl+0x72/0xd0
  ? srso_alias_return_thunk+0x5/0x7f
  ? syscall_exit_to_user_mode+0x2b/0x40
  ? srso_alias_return_thunk+0x5/0x7f
  ? do_syscall_64+0x6c/0x90
  ? srso_alias_return_thunk+0x5/0x7f
  ? exit_to_user_mode_prepare+0x142/0x1f0
  ? srso_alias_return_thunk+0x5/0x7f
  ? syscall_exit_to_user_mode+0x2b/0x40
  ? srso_alias_return_thunk+0x5/0x7f
  ? do_syscall_64+0x6c/0x90
  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
 RIP: 0033:0x7f2ffb321594
 Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 80 3d d5 cd 0d 00 00 74 13 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 3c c3 0f 1f 00 55 48 89 e5 48 83 ec 10 89 7d
 RSP: 002b:00007ffe8d8eef18 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
 RAX: ffffffffffffffda RBX: 00007f2ffba4e668 RCX: 00007f2ffb321594
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
 RBP: 00007ffe8d8eef40 R08: 0000000000000000 R09: 0000000000000000
 R10: 55c926e3167eae79 R11: 0000000000000202 R12: 0000000000000003
 R13: 00007ffe8d8ef030 R14: 0000000000000000 R15: 00007f2ffba4e668
  </TASK>
 CR2: 0000000000000010
 ---[ end trace 0000000000000000 ]---

Move hrtimer_init to timerlat_fd open() to avoid this problem.

Link: https://lore.kernel.org/linux-trace-kernel/7324dd3fc0035658c99b825204a66049389c56e3.1706798888.git.bristot@kernel.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: stable@vger.kernel.org
Fixes: e88ed227f6 ("tracing/timerlat: Add user-space interface")
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-02-01 11:50:13 -05:00
Daniel Xu
6f3189f38a bpf: treewide: Annotate BPF kfuncs in BTF 
This commit marks kfuncs as such inside the .BTF_ids section. The upshot
of these annotations is that we'll be able to automatically generate
kfunc prototypes for downstream users. The process is as follows:

1. In source, use BTF_KFUNCS_START/END macro pair to mark kfuncs
2. During build, pahole injects into BTF a "bpf_kfunc" BTF_DECL_TAG for
   each function inside BTF_KFUNCS sets
3. At runtime, vmlinux or module BTF is made available in sysfs
4. At runtime, bpftool (or similar) can look at provided BTF and
   generate appropriate prototypes for functions with "bpf_kfunc" tag

To ensure future kfunc are similarly tagged, we now also return error
inside kfunc registration for untagged kfuncs. For vmlinux kfuncs,
we also WARN(), as initcall machinery does not handle errors.

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Acked-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/e55150ceecbf0a5d961e608941165c0bee7bc943.1706491398.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
 2024-01-31 20:40:56 -08:00
Vincent Donnefort
66bbea9ed6 ring-buffer: Clean ring_buffer_poll_wait() error return 
The return type for ring_buffer_poll_wait() is __poll_t. This is behind
the scenes an unsigned where we can set event bits. In case of a
non-allocated CPU, we do return instead -EINVAL (0xffffffea). Lucky us,
this ends up setting few error bits (EPOLLERR | EPOLLHUP | EPOLLNVAL), so
user-space at least is aware something went wrong.

Nonetheless, this is an incorrect code. Replace that -EINVAL with a
proper EPOLLERR to clean that output. As this doesn't change the
behaviour, there's no need to treat this change as a bug fix.

Link: https://lore.kernel.org/linux-trace-kernel/20240131140955.3322792-1-vdonnefort@google.com

Cc: stable@vger.kernel.org
Fixes: 6721cb6002 ("ring-buffer: Do not poll non allocated cpu buffers")
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-01-31 14:10:24 -05:00
Jakub Kicinski
92046e83c0 bpf-next-for-netdev 
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-01-26

We've added 107 non-merge commits during the last 4 day(s) which contain
a total of 101 files changed, 6009 insertions(+), 1260 deletions(-).

The main changes are:

1) Add BPF token support to delegate a subset of BPF subsystem
   functionality from privileged system-wide daemons such as systemd
   through special mount options for userns-bound BPF fs to a trusted
   & unprivileged application. With addressed changes from Christian
   and Linus' reviews, from Andrii Nakryiko.

2) Support registration of struct_ops types from modules which helps
   projects like fuse-bpf that seeks to implement a new struct_ops type,
   from Kui-Feng Lee.

3) Add support for retrieval of cookies for perf/kprobe multi links,
   from Jiri Olsa.

4) Bigger batch of prep-work for the BPF verifier to eventually support
   preserving boundaries and tracking scalars on narrowing fills,
   from Maxim Mikityanskiy.

5) Extend the tc BPF flavor to support arbitrary TCP SYN cookies to help
   with the scenario of SYN floods, from Kuniyuki Iwashima.

6) Add code generation to inline the bpf_kptr_xchg() helper which
   improves performance when stashing/popping the allocated BPF objects,
   from Hou Tao.

7) Extend BPF verifier to track aligned ST stores as imprecise spilled
   registers, from Yonghong Song.

8) Several fixes to BPF selftests around inline asm constraints and
   unsupported VLA code generation, from Jose E. Marchesi.

9) Various updates to the BPF IETF instruction set draft document such
   as the introduction of conformance groups for instructions,
   from Dave Thaler.

10) Fix BPF verifier to make infinite loop detection in is_state_visited()
    exact to catch some too lax spill/fill corner cases,
    from Eduard Zingerman.

11) Refactor the BPF verifier pointer ALU check to allow ALU explicitly
    instead of implicitly for various register types, from Hao Sun.

12) Fix the flaky tc_redirect_dtime BPF selftest due to slowness
    in neighbor advertisement at setup time, from Martin KaFai Lau.

13) Change BPF selftests to skip callback tests for the case when the
    JIT is disabled, from Tiezhu Yang.

14) Add a small extension to libbpf which allows to auto create
    a map-in-map's inner map, from Andrey Grafin.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (107 commits)
  selftests/bpf: Add missing line break in test_verifier
  bpf, docs: Clarify definitions of various instructions
  bpf: Fix error checks against bpf_get_btf_vmlinux().
  bpf: One more maintainer for libbpf and BPF selftests
  selftests/bpf: Incorporate LSM policy to token-based tests
  selftests/bpf: Add tests for LIBBPF_BPF_TOKEN_PATH envvar
  libbpf: Support BPF token path setting through LIBBPF_BPF_TOKEN_PATH envvar
  selftests/bpf: Add tests for BPF object load with implicit token
  selftests/bpf: Add BPF object loading tests with explicit token passing
  libbpf: Wire up BPF token support at BPF object level
  libbpf: Wire up token_fd into feature probing logic
  libbpf: Move feature detection code into its own file
  libbpf: Further decouple feature checking logic from bpf_object
  libbpf: Split feature detectors definitions from cached results
  selftests/bpf: Utilize string values for delegate_xxx mount options
  bpf: Support symbolic BPF FS delegation mount options
  bpf: Fail BPF_TOKEN_CREATE if no delegation option was set on BPF FS
  bpf,selinux: Allocate bpf_security_struct per BPF token
  selftests/bpf: Add BPF token-enabled tests
  libbpf: Add BPF token support to bpf_prog_load() API
  ...
====================

Link: https://lore.kernel.org/r/20240126215710.19855-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2024-01-26 21:08:22 -08:00
Masami Hiramatsu (Google)
0958b33ef5 tracing/trigger: Fix to return error if failed to alloc snapshot 
Fix register_snapshot_trigger() to return error code if it failed to
allocate a snapshot instead of 0 (success). Unless that, it will register
snapshot trigger without an error.

Link: https://lore.kernel.org/linux-trace-kernel/170622977792.270660.2789298642759362200.stgit@devnote2

Fixes: 0bbe7f7199 ("tracing: Fix the race between registering 'snapshot' event trigger and triggering 'snapshot' operation")
Cc: stable@vger.kernel.org
Cc: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-01-26 15:10:24 -05:00
Andrii Nakryiko
bbc1d24724 bpf: Take into account BPF token when fetching helper protos 
Instead of performing unconditional system-wide bpf_capable() and
perfmon_capable() calls inside bpf_base_func_proto() function (and other
similar ones) to determine eligibility of a given BPF helper for a given
program, use previously recorded BPF token during BPF_PROG_LOAD command
handling to inform the decision.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-8-andrii@kernel.org
 2024-01-24 16:21:01 -08:00
Jiri Olsa
9fd112b1f8 bpf: Store cookies in kprobe_multi bpf_link_info data 
Storing cookies in kprobe_multi bpf_link_info data. The cookies
field is optional and if provided it needs to be an array of
__u64 with kprobe_multi.count length.

Acked-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240119110505.400573-3-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
 2024-01-23 16:05:27 -08:00
Petr Pavlu
2b44760609 tracing: Ensure visibility when inserting an element into tracing_map 
Running the following two commands in parallel on a multi-processor
AArch64 machine can sporadically produce an unexpected warning about
duplicate histogram entries:

 $ while true; do
     echo hist:key=id.syscall:val=hitcount > \
       /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger
     cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist
     sleep 0.001
   done
 $ stress-ng --sysbadaddr $(nproc)

The warning looks as follows:

[ 2911.172474] ------------[ cut here ]------------
[ 2911.173111] Duplicates detected: 1
[ 2911.173574] WARNING: CPU: 2 PID: 12247 at kernel/trace/tracing_map.c:983 tracing_map_sort_entries+0x3e0/0x408
[ 2911.174702] Modules linked in: iscsi_ibft(E) iscsi_boot_sysfs(E) rfkill(E) af_packet(E) nls_iso8859_1(E) nls_cp437(E) vfat(E) fat(E) ena(E) tiny_power_button(E) qemu_fw_cfg(E) button(E) fuse(E) efi_pstore(E) ip_tables(E) x_tables(E) xfs(E) libcrc32c(E) aes_ce_blk(E) aes_ce_cipher(E) crct10dif_ce(E) polyval_ce(E) polyval_generic(E) ghash_ce(E) gf128mul(E) sm4_ce_gcm(E) sm4_ce_ccm(E) sm4_ce(E) sm4_ce_cipher(E) sm4(E) sm3_ce(E) sm3(E) sha3_ce(E) sha512_ce(E) sha512_arm64(E) sha2_ce(E) sha256_arm64(E) nvme(E) sha1_ce(E) nvme_core(E) nvme_auth(E) t10_pi(E) sg(E) scsi_mod(E) scsi_common(E) efivarfs(E)
[ 2911.174738] Unloaded tainted modules: cppc_cpufreq(E):1
[ 2911.180985] CPU: 2 PID: 12247 Comm: cat Kdump: loaded Tainted: G            E      6.7.0-default #2 1b58bbb22c97e4399dc09f92d309344f69c44a01
[ 2911.182398] Hardware name: Amazon EC2 c7g.8xlarge/, BIOS 1.0 11/1/2018
[ 2911.183208] pstate: 61400005 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
[ 2911.184038] pc : tracing_map_sort_entries+0x3e0/0x408
[ 2911.184667] lr : tracing_map_sort_entries+0x3e0/0x408
[ 2911.185310] sp : ffff8000a1513900
[ 2911.185750] x29: ffff8000a1513900 x28: ffff0003f272fe80 x27: 0000000000000001
[ 2911.186600] x26: ffff0003f272fe80 x25: 0000000000000030 x24: 0000000000000008
[ 2911.187458] x23: ffff0003c5788000 x22: ffff0003c16710c8 x21: ffff80008017f180
[ 2911.188310] x20: ffff80008017f000 x19: ffff80008017f180 x18: ffffffffffffffff
[ 2911.189160] x17: 0000000000000000 x16: 0000000000000000 x15: ffff8000a15134b8
[ 2911.190015] x14: 0000000000000000 x13: 205d373432323154 x12: 5b5d313131333731
[ 2911.190844] x11: 00000000fffeffff x10: 00000000fffeffff x9 : ffffd1b78274a13c
[ 2911.191716] x8 : 000000000017ffe8 x7 : c0000000fffeffff x6 : 000000000057ffa8
[ 2911.192554] x5 : ffff0012f6c24ec0 x4 : 0000000000000000 x3 : ffff2e5b72b5d000
[ 2911.193404] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0003ff254480
[ 2911.194259] Call trace:
[ 2911.194626]  tracing_map_sort_entries+0x3e0/0x408
[ 2911.195220]  hist_show+0x124/0x800
[ 2911.195692]  seq_read_iter+0x1d4/0x4e8
[ 2911.196193]  seq_read+0xe8/0x138
[ 2911.196638]  vfs_read+0xc8/0x300
[ 2911.197078]  ksys_read+0x70/0x108
[ 2911.197534]  __arm64_sys_read+0x24/0x38
[ 2911.198046]  invoke_syscall+0x78/0x108
[ 2911.198553]  el0_svc_common.constprop.0+0xd0/0xf8
[ 2911.199157]  do_el0_svc+0x28/0x40
[ 2911.199613]  el0_svc+0x40/0x178
[ 2911.200048]  el0t_64_sync_handler+0x13c/0x158
[ 2911.200621]  el0t_64_sync+0x1a8/0x1b0
[ 2911.201115] ---[ end trace 0000000000000000 ]---

The problem appears to be caused by CPU reordering of writes issued from
__tracing_map_insert().

The check for the presence of an element with a given key in this
function is:

 val = READ_ONCE(entry->val);
 if (val && keys_match(key, val->key, map->key_size)) ...

The write of a new entry is:

 elt = get_free_elt(map);
 memcpy(elt->key, key, map->key_size);
 entry->val = elt;

The "memcpy(elt->key, key, map->key_size);" and "entry->val = elt;"
stores may become visible in the reversed order on another CPU. This
second CPU might then incorrectly determine that a new key doesn't match
an already present val->key and subsequently insert a new element,
resulting in a duplicate.

Fix the problem by adding a write barrier between
"memcpy(elt->key, key, map->key_size);" and "entry->val = elt;", and for
good measure, also use WRITE_ONCE(entry->val, elt) for publishing the
element. The sequence pairs with the mentioned "READ_ONCE(entry->val);"
and the "val->key" check which has an address dependency.

The barrier is placed on a path executed when adding an element for
a new key. Subsequent updates targeting the same key remain unaffected.

From the user's perspective, the issue was introduced by commit
c193707dde ("tracing: Remove code which merges duplicates"), which
followed commit cbf4100efb ("tracing: Add support to detect and avoid
duplicates"). The previous code operated differently; it inherently
expected potential races which result in duplicates but merged them
later when they occurred.

Link: https://lore.kernel.org/linux-trace-kernel/20240122150928.27725-1-petr.pavlu@suse.com

Fixes: c193707dde ("tracing: Remove code which merges duplicates")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-01-22 17:15:40 -05:00
Linus Torvalds
a2ded784cd tracing updates for 6.8: 
- Allow kernel trace instance creation to specify what events are created
   Inside the kernel, a subsystem may create a tracing instance that it can
   use to send events to user space. This sub-system may not care about the
   thousands of events that exist in eventfs. Allow the sub-system to specify
   what sub-systems of events it cares about, and only those events are exposed
   to this instance.
 
 - Allow the ring buffer to be broken up into bigger sub-buffers than just the
   architecture page size. A new tracefs file called "buffer_subbuf_size_kb"
   is created. The user can now specify a minimum size the sub-buffer may be
   in kilobytes. Note, that the implementation currently make the sub-buffer
   size a power of 2 pages (1, 2, 4, 8, 16, ...) but the user only writes in
   kilobyte size, and the sub-buffer will be updated to the next size that
   it will can accommodate it. If the user writes in 10, it will change the
   size to be 4 pages on x86 (16K), as that is the next available size that
   can hold 10K pages.
 
 - Update the debug output when a corrupt time is detected in the ring buffer.
   If the ring buffer detects inconsistent timestamps, there's a debug config
   options that will dump the contents of the meta data of the sub-buffer that
   is used for debugging. Add some more information to this dump that helps
   with debugging.
 
 - Add more timestamp debugging checks (only triggers when the config is enabled)
 
 - Increase the trace_seq iterator to 2 page sizes.
 
 - Allow strings written into tracefs_marker to be larger. Up to just under
   2 page sizes (based on what trace_seq can hold).
 
 - Increase the trace_maker_raw write to be as big as a sub-buffer can hold.
 
 - Remove 32 bit time stamp logic, now that the rb_time_cmpxchg() has been
   removed.
 
 - More selftests were added.
 
 - Some code clean ups as well.
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Merge tag 'trace-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing updates from Steven Rostedt:

 - Allow kernel trace instance creation to specify what events are
   created

   Inside the kernel, a subsystem may create a tracing instance that it
   can use to send events to user space. This sub-system may not care
   about the thousands of events that exist in eventfs. Allow the
   sub-system to specify what sub-systems of events it cares about, and
   only those events are exposed to this instance.

 - Allow the ring buffer to be broken up into bigger sub-buffers than
   just the architecture page size.

   A new tracefs file called "buffer_subbuf_size_kb" is created. The
   user can now specify a minimum size the sub-buffer may be in
   kilobytes. Note, that the implementation currently make the
   sub-buffer size a power of 2 pages (1, 2, 4, 8, 16, ...) but the user
   only writes in kilobyte size, and the sub-buffer will be updated to
   the next size that it will can accommodate it. If the user writes in
   10, it will change the size to be 4 pages on x86 (16K), as that is
   the next available size that can hold 10K pages.

 - Update the debug output when a corrupt time is detected in the ring
   buffer. If the ring buffer detects inconsistent timestamps, there's a
   debug config options that will dump the contents of the meta data of
   the sub-buffer that is used for debugging. Add some more information
   to this dump that helps with debugging.

 - Add more timestamp debugging checks (only triggers when the config is
   enabled)

 - Increase the trace_seq iterator to 2 page sizes.

 - Allow strings written into tracefs_marker to be larger. Up to just
   under 2 page sizes (based on what trace_seq can hold).

 - Increase the trace_maker_raw write to be as big as a sub-buffer can
   hold.

 - Remove 32 bit time stamp logic, now that the rb_time_cmpxchg() has
   been removed.

 - More selftests were added.

 - Some code clean ups as well.

* tag 'trace-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (29 commits)
  ring-buffer: Remove stale comment from ring_buffer_size()
  tracing histograms: Simplify parse_actions() function
  tracing/selftests: Remove exec permissions from trace_marker.tc test
  ring-buffer: Use subbuf_order for buffer page masking
  tracing: Update subbuffer with kilobytes not page order
  ringbuffer/selftest: Add basic selftest to test changing subbuf order
  ring-buffer: Add documentation on the buffer_subbuf_order file
  ring-buffer: Just update the subbuffers when changing their allocation order
  ring-buffer: Keep the same size when updating the order
  tracing: Stop the tracing while changing the ring buffer subbuf size
  tracing: Update snapshot order along with main buffer order
  ring-buffer: Make sure the spare sub buffer used for reads has same size
  ring-buffer: Do no swap cpu buffers if order is different
  ring-buffer: Clear pages on error in ring_buffer_subbuf_order_set() failure
  ring-buffer: Read and write to ring buffers with custom sub buffer size
  ring-buffer: Set new size of the ring buffer sub page
  ring-buffer: Add interface for configuring trace sub buffer size
  ring-buffer: Page size per ring buffer
  ring-buffer: Have ring_buffer_print_page_header() be able to access ring_buffer_iter
  ring-buffer: Check if absolute timestamp goes backwards
  ...
 2024-01-18 14:35:29 -08:00
Linus Torvalds
5b890ad456 Probes update for v6.8: 
- Kprobes trace event to show the actual function name in notrace-symbol
   warning. Instead of using user specified symbol name, use "%ps" printk
   format to show the actual symbol at the probe address. Since kprobe
   event accepts the offset from symbol which is bigger than the symbol
   size, user specified symbol may not be the actual probed symbol.
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Merge tag 'probes-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes update from Masami Hiramatsu:

 - Update the Kprobes trace event to show the actual function name in
   notrace-symbol warning.

   Instead of using the user specified symbol name, use "%ps" printk
   format to show the actual symbol at the probe address. Since kprobe
   event accepts the offset from symbol which is bigger than the symbol
   size, the user specified symbol may not be the actual probed symbol.

* tag 'probes-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  trace/kprobe: Display the actual notrace function when rejecting a probe
 2024-01-18 14:21:22 -08:00
Linus Torvalds
3e7aeb78ab Networking changes for 6.8. 
Core & protocols
 ----------------
 
  - Analyze and reorganize core networking structs (socks, netdev,
    netns, mibs) to optimize cacheline consumption and set up
    build time warnings to safeguard against future header changes.
    This improves TCP performances with many concurrent connections
    up to 40%.
 
  - Add page-pool netlink-based introspection, exposing the
    memory usage and recycling stats. This helps indentify
    bad PP users and possible leaks.
 
  - Refine TCP/DCCP source port selection to no longer favor even
    source port at connect() time when IP_LOCAL_PORT_RANGE is set.
    This lowers the time taken by connect() for hosts having
    many active connections to the same destination.
 
  - Refactor the TCP bind conflict code, shrinking related socket
    structs.
 
  - Refactor TCP SYN-Cookie handling, as a preparation step to
    allow arbitrary SYN-Cookie processing via eBPF.
 
  - Tune optmem_max for 0-copy usage, increasing the default value
    to 128KB and namespecifying it.
 
  - Allow coalescing for cloned skbs coming from page pools, improving
    RX performances with some common configurations.
 
  - Reduce extension header parsing overhead at GRO time.
 
  - Add bridge MDB bulk deletion support, allowing user-space to
    request the deletion of matching entries.
 
  - Reorder nftables struct members, to keep data accessed by the
    datapath first.
 
  - Introduce TC block ports tracking and use. This allows supporting
    multicast-like behavior at the TC layer.
 
  - Remove UAPI support for retired TC qdiscs (dsmark, CBQ and ATM) and
    classifiers (RSVP and tcindex).
 
  - More data-race annotations.
 
  - Extend the diag interface to dump TCP bound-only sockets.
 
  - Conditional notification of events for TC qdisc class and actions.
 
  - Support for WPAN dynamic associations with nearby devices, to form
    a sub-network using a specific PAN ID.
 
  - Implement SMCv2.1 virtual ISM device support.
 
  - Add support for Batman-avd mulicast packet type.
 
 BPF
 ---
 
  - Tons of verifier improvements:
    - BPF register bounds logic and range support along with a large
      test suite
    - log improvements
    - complete precision tracking support for register spills
    - track aligned STACK_ZERO cases as imprecise spilled registers. It
      improves the verifier "instructions processed" metric from single
      digit to 50-60% for some programs
    - support for user's global BPF subprogram arguments with few
      commonly requested annotations for a better developer experience
    - support tracking of BPF_JNE which helps cases when the compiler
      transforms (unsigned) "a > 0" into "if a == 0 goto xxx" and the
      like
    - several fixes
 
  - Add initial TX metadata implementation for AF_XDP with support in
    mlx5 and stmmac drivers. Two types of offloads are supported right
    now, that is, TX timestamp and TX checksum offload.
 
  - Fix kCFI bugs in BPF all forms of indirect calls from BPF into
    kernel and from kernel into BPF work with CFI enabled. This allows
    BPF to work with CONFIG_FINEIBT=y.
 
  - Change BPF verifier logic to validate global subprograms lazily
    instead of unconditionally before the main program, so they can be
    guarded using BPF CO-RE techniques.
 
  - Support uid/gid options when mounting bpffs.
 
  - Add a new kfunc which acquires the associated cgroup of a task
    within a specific cgroup v1 hierarchy where the latter is identified
    by its id.
 
  - Extend verifier to allow bpf_refcount_acquire() of a map value field
    obtained via direct load which is a use-case needed in sched_ext.
 
  - Add BPF link_info support for uprobe multi link along with bpftool
    integration for the latter.
 
  - Support for VLAN tag in XDP hints.
 
  - Remove deprecated bpfilter kernel leftovers given the project
    is developed in user-space (https://github.com/facebook/bpfilter).
 
 Misc
 ----
 
  - Support for parellel TC self-tests execution.
 
  - Increase MPTCP self-tests coverage.
 
  - Updated the bridge documentation, including several so-far
    undocumented features.
 
  - Convert all the net self-tests to run in unique netns, to
    avoid random failures due to conflict and allow concurrent
    runs.
 
  - Add TCP-AO self-tests.
 
  - Add kunit tests for both cfg80211 and mac80211.
 
  - Autogenerate Netlink families documentation from YAML spec.
 
  - Add yml-gen support for fixed headers and recursive nests, the
    tool can now generate user-space code for all genetlink families
    for which we have specs.
 
  - A bunch of additional module descriptions fixes.
 
  - Catch incorrect freeing of pages belonging to a page pool.
 
 Driver API
 ----------
 
  - Rust abstractions for network PHY drivers; do not cover yet the
    full C API, but already allow implementing functional PHY drivers
    in rust.
 
  - Introduce queue and NAPI support in the netdev Netlink interface,
    allowing complete access to the device <> NAPIs <> queues
    relationship.
 
  - Introduce notifications filtering for devlink to allow control
    application scale to thousands of instances.
 
  - Improve PHY validation, requesting rate matching information for
    each ethtool link mode supported by both the PHY and host.
 
  - Add support for ethtool symmetric-xor RSS hash.
 
  - ACPI based Wifi band RFI (WBRF) mitigation feature for the AMD
    platform.
 
  - Expose pin fractional frequency offset value over new DPLL generic
    netlink attribute.
 
  - Convert older drivers to platform remove callback returning void.
 
  - Add support for PHY package MMD read/write.
 
 New hardware / drivers
 ----------------------
 
  - Ethernet:
    - Octeon CN10K devices
    - Broadcom 5760X P7
    - Qualcomm SM8550 SoC
    - Texas Instrument DP83TG720S PHY
 
  - Bluetooth:
    - IMC Networks Bluetooth radio
 
 Removed
 -------
 
  - WiFi:
    - libertas 16-bit PCMCIA support
    - Atmel at76c50x drivers
    - HostAP ISA/PCMCIA style 802.11b driver
    - zd1201 802.11b USB dongles
    - Orinoco ISA/PCMCIA 802.11b driver
    - Aviator/Raytheon driver
    - Planet WL3501 driver
    - RNDIS USB 802.11b driver
 
 Drivers
 -------
 
  - Ethernet high-speed NICs:
    - Intel (100G, ice, idpf):
      - allow one by one port representors creation and removal
      - add temperature and clock information reporting
      - add get/set for ethtool's header split ringparam
      - add again FW logging
      - adds support switchdev hardware packet mirroring
      - iavf: implement symmetric-xor RSS hash
      - igc: add support for concurrent physical and free-running timers
      - i40e: increase the allowable descriptors
    - nVidia/Mellanox:
      - Preparation for Socket-Direct multi-dev netdev. That will allow
        in future releases combining multiple PFs devices attached to
        different NUMA nodes under the same netdev
    - Broadcom (bnxt):
      - TX completion handling improvements
      - add basic ntuple filter support
      - reduce MSIX vectors usage for MQPRIO offload
      - add VXLAN support, USO offload and TX coalesce completion for P7
    - Marvell Octeon EP:
      - xmit-more support
      - add PF-VF mailbox support and use it for FW notifications for VFs
    - Wangxun (ngbe/txgbe):
      - implement ethtool functions to operate pause param, ring param,
        coalesce channel number and msglevel
    - Netronome/Corigine (nfp):
      - add flow-steering support
      - support UDP segmentation offload
 
  - Ethernet NICs embedded, slower, virtual:
    - Xilinx AXI: remove duplicate DMA code adopting the dma engine driver
    - stmmac: add support for HW-accelerated VLAN stripping
    - TI AM654x sw: add mqprio, frame preemption & coalescing
    - gve: add support for non-4k page sizes.
    - virtio-net: support dynamic coalescing moderation
 
  - nVidia/Mellanox Ethernet datacenter switches:
    - allow firmware upgrade without a reboot
    - more flexible support for bridge flooding via the compressed
      FID flooding mode
 
  - Ethernet embedded switches:
    - Microchip:
      - fine-tune flow control and speed configurations in KSZ8xxx
      - KSZ88X3: enable setting rmii reference
    - Renesas:
      - add jumbo frames support
    - Marvell:
      - 88E6xxx: add "eth-mac" and "rmon" stats support
 
  - Ethernet PHYs:
    - aquantia: add firmware load support
    - at803x: refactor the driver to simplify adding support for more
      chip variants
    - NXP C45 TJA11xx: Add MACsec offload support
 
  - Wifi:
    - MediaTek (mt76):
      - NVMEM EEPROM improvements
      - mt7996 Extremely High Throughput (EHT) improvements
      - mt7996 Wireless Ethernet Dispatcher (WED) support
      - mt7996 36-bit DMA support
    - Qualcomm (ath12k):
      - support for a single MSI vector
      - WCN7850: support AP mode
    - Intel (iwlwifi):
      - new debugfs file fw_dbg_clear
      - allow concurrent P2P operation on DFS channels
 
  - Bluetooth:
    - QCA2066: support HFP offload
    - ISO: more broadcast-related improvements
    - NXP: better recovery in case receiver/transmitter get out of sync
 
 Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-next-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Paolo Abeni:
 "The most interesting thing is probably the networking structs
  reorganization and a significant amount of changes is around
  self-tests.

  Core & protocols:

   - Analyze and reorganize core networking structs (socks, netdev,
     netns, mibs) to optimize cacheline consumption and set up build
     time warnings to safeguard against future header changes

     This improves TCP performances with many concurrent connections up
     to 40%

   - Add page-pool netlink-based introspection, exposing the memory
     usage and recycling stats. This helps indentify bad PP users and
     possible leaks

   - Refine TCP/DCCP source port selection to no longer favor even
     source port at connect() time when IP_LOCAL_PORT_RANGE is set. This
     lowers the time taken by connect() for hosts having many active
     connections to the same destination

   - Refactor the TCP bind conflict code, shrinking related socket
     structs

   - Refactor TCP SYN-Cookie handling, as a preparation step to allow
     arbitrary SYN-Cookie processing via eBPF

   - Tune optmem_max for 0-copy usage, increasing the default value to
     128KB and namespecifying it

   - Allow coalescing for cloned skbs coming from page pools, improving
     RX performances with some common configurations

   - Reduce extension header parsing overhead at GRO time

   - Add bridge MDB bulk deletion support, allowing user-space to
     request the deletion of matching entries

   - Reorder nftables struct members, to keep data accessed by the
     datapath first

   - Introduce TC block ports tracking and use. This allows supporting
     multicast-like behavior at the TC layer

   - Remove UAPI support for retired TC qdiscs (dsmark, CBQ and ATM) and
     classifiers (RSVP and tcindex)

   - More data-race annotations

   - Extend the diag interface to dump TCP bound-only sockets

   - Conditional notification of events for TC qdisc class and actions

   - Support for WPAN dynamic associations with nearby devices, to form
     a sub-network using a specific PAN ID

   - Implement SMCv2.1 virtual ISM device support

   - Add support for Batman-avd mulicast packet type

  BPF:

   - Tons of verifier improvements:
       - BPF register bounds logic and range support along with a large
         test suite
       - log improvements
       - complete precision tracking support for register spills
       - track aligned STACK_ZERO cases as imprecise spilled registers.
         This improves the verifier "instructions processed" metric from
         single digit to 50-60% for some programs
       - support for user's global BPF subprogram arguments with few
         commonly requested annotations for a better developer
         experience
       - support tracking of BPF_JNE which helps cases when the compiler
         transforms (unsigned) "a > 0" into "if a == 0 goto xxx" and the
         like
       - several fixes

   - Add initial TX metadata implementation for AF_XDP with support in
     mlx5 and stmmac drivers. Two types of offloads are supported right
     now, that is, TX timestamp and TX checksum offload

   - Fix kCFI bugs in BPF all forms of indirect calls from BPF into
     kernel and from kernel into BPF work with CFI enabled. This allows
     BPF to work with CONFIG_FINEIBT=y

   - Change BPF verifier logic to validate global subprograms lazily
     instead of unconditionally before the main program, so they can be
     guarded using BPF CO-RE techniques

   - Support uid/gid options when mounting bpffs

   - Add a new kfunc which acquires the associated cgroup of a task
     within a specific cgroup v1 hierarchy where the latter is
     identified by its id

   - Extend verifier to allow bpf_refcount_acquire() of a map value
     field obtained via direct load which is a use-case needed in
     sched_ext

   - Add BPF link_info support for uprobe multi link along with bpftool
     integration for the latter

   - Support for VLAN tag in XDP hints

   - Remove deprecated bpfilter kernel leftovers given the project is
     developed in user-space (https://github.com/facebook/bpfilter)

  Misc:

   - Support for parellel TC self-tests execution

   - Increase MPTCP self-tests coverage

   - Updated the bridge documentation, including several so-far
     undocumented features

   - Convert all the net self-tests to run in unique netns, to avoid
     random failures due to conflict and allow concurrent runs

   - Add TCP-AO self-tests

   - Add kunit tests for both cfg80211 and mac80211

   - Autogenerate Netlink families documentation from YAML spec

   - Add yml-gen support for fixed headers and recursive nests, the tool
     can now generate user-space code for all genetlink families for
     which we have specs

   - A bunch of additional module descriptions fixes

   - Catch incorrect freeing of pages belonging to a page pool

  Driver API:

   - Rust abstractions for network PHY drivers; do not cover yet the
     full C API, but already allow implementing functional PHY drivers
     in rust

   - Introduce queue and NAPI support in the netdev Netlink interface,
     allowing complete access to the device <> NAPIs <> queues
     relationship

   - Introduce notifications filtering for devlink to allow control
     application scale to thousands of instances

   - Improve PHY validation, requesting rate matching information for
     each ethtool link mode supported by both the PHY and host

   - Add support for ethtool symmetric-xor RSS hash

   - ACPI based Wifi band RFI (WBRF) mitigation feature for the AMD
     platform

   - Expose pin fractional frequency offset value over new DPLL generic
     netlink attribute

   - Convert older drivers to platform remove callback returning void

   - Add support for PHY package MMD read/write

  New hardware / drivers:

   - Ethernet:
       - Octeon CN10K devices
       - Broadcom 5760X P7
       - Qualcomm SM8550 SoC
       - Texas Instrument DP83TG720S PHY

   - Bluetooth:
       - IMC Networks Bluetooth radio

  Removed:

   - WiFi:
       - libertas 16-bit PCMCIA support
       - Atmel at76c50x drivers
       - HostAP ISA/PCMCIA style 802.11b driver
       - zd1201 802.11b USB dongles
       - Orinoco ISA/PCMCIA 802.11b driver
       - Aviator/Raytheon driver
       - Planet WL3501 driver
       - RNDIS USB 802.11b driver

  Driver updates:

   - Ethernet high-speed NICs:
       - Intel (100G, ice, idpf):
          - allow one by one port representors creation and removal
          - add temperature and clock information reporting
          - add get/set for ethtool's header split ringparam
          - add again FW logging
          - adds support switchdev hardware packet mirroring
          - iavf: implement symmetric-xor RSS hash
          - igc: add support for concurrent physical and free-running
            timers
          - i40e: increase the allowable descriptors
       - nVidia/Mellanox:
          - Preparation for Socket-Direct multi-dev netdev. That will
            allow in future releases combining multiple PFs devices
            attached to different NUMA nodes under the same netdev
       - Broadcom (bnxt):
          - TX completion handling improvements
          - add basic ntuple filter support
          - reduce MSIX vectors usage for MQPRIO offload
          - add VXLAN support, USO offload and TX coalesce completion
            for P7
       - Marvell Octeon EP:
          - xmit-more support
          - add PF-VF mailbox support and use it for FW notifications
            for VFs
       - Wangxun (ngbe/txgbe):
          - implement ethtool functions to operate pause param, ring
            param, coalesce channel number and msglevel
       - Netronome/Corigine (nfp):
          - add flow-steering support
          - support UDP segmentation offload

   - Ethernet NICs embedded, slower, virtual:
       - Xilinx AXI: remove duplicate DMA code adopting the dma engine
         driver
       - stmmac: add support for HW-accelerated VLAN stripping
       - TI AM654x sw: add mqprio, frame preemption & coalescing
       - gve: add support for non-4k page sizes.
       - virtio-net: support dynamic coalescing moderation

   - nVidia/Mellanox Ethernet datacenter switches:
       - allow firmware upgrade without a reboot
       - more flexible support for bridge flooding via the compressed
         FID flooding mode

   - Ethernet embedded switches:
       - Microchip:
          - fine-tune flow control and speed configurations in KSZ8xxx
          - KSZ88X3: enable setting rmii reference
       - Renesas:
          - add jumbo frames support
       - Marvell:
          - 88E6xxx: add "eth-mac" and "rmon" stats support

   - Ethernet PHYs:
       - aquantia: add firmware load support
       - at803x: refactor the driver to simplify adding support for more
         chip variants
       - NXP C45 TJA11xx: Add MACsec offload support

   - Wifi:
       - MediaTek (mt76):
          - NVMEM EEPROM improvements
          - mt7996 Extremely High Throughput (EHT) improvements
          - mt7996 Wireless Ethernet Dispatcher (WED) support
          - mt7996 36-bit DMA support
       - Qualcomm (ath12k):
          - support for a single MSI vector
          - WCN7850: support AP mode
       - Intel (iwlwifi):
          - new debugfs file fw_dbg_clear
          - allow concurrent P2P operation on DFS channels

   - Bluetooth:
       - QCA2066: support HFP offload
       - ISO: more broadcast-related improvements
       - NXP: better recovery in case receiver/transmitter get out of sync"

* tag 'net-next-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1714 commits)
  lan78xx: remove redundant statement in lan78xx_get_eee
  lan743x: remove redundant statement in lan743x_ethtool_get_eee
  bnxt_en: Fix RCU locking for ntuple filters in bnxt_rx_flow_steer()
  bnxt_en: Fix RCU locking for ntuple filters in bnxt_srxclsrldel()
  bnxt_en: Remove unneeded variable in bnxt_hwrm_clear_vnic_filter()
  tcp: Revert no longer abort SYN_SENT when receiving some ICMP
  Revert "mlx5 updates 2023-12-20"
  Revert "net: stmmac: Enable Per DMA Channel interrupt"
  ipvlan: Remove usage of the deprecated ida_simple_xx() API
  ipvlan: Fix a typo in a comment
  net/sched: Remove ipt action tests
  net: stmmac: Use interrupt mode INTM=1 for per channel irq
  net: stmmac: Add support for TX/RX channel interrupt
  net: stmmac: Make MSI interrupt routine generic
  dt-bindings: net: snps,dwmac: per channel irq
  net: phy: at803x: make read_status more generic
  net: phy: at803x: add support for cdt cross short test for qca808x
  net: phy: at803x: refactor qca808x cable test get status function
  net: phy: at803x: generalize cdt fault length function
  net: ethernet: cortina: Drop TSO support
  ...
 2024-01-11 10:07:29 -08:00
Linus Torvalds
120a201bd2 hardening updates for v6.8-rc1 
- Introduce the param_unknown_fn type and other clean ups (Andy Shevchenko)
 
 - Various __counted_by annotations (Christophe JAILLET, Gustavo A. R. Silva,
   Kees Cook)
 
 - Add KFENCE test to LKDTM (Stephen Boyd)
 
 - Various strncpy() refactorings (Justin Stitt)
 
 - Fix qnx4 to avoid writing into the smaller of two overlapping buffers
 
 - Various strlcpy() refactorings
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Merge tag 'hardening-v6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardening updates from Kees Cook:

 - Introduce the param_unknown_fn type and other clean ups (Andy
   Shevchenko)

 - Various __counted_by annotations (Christophe JAILLET, Gustavo A. R.
   Silva, Kees Cook)

 - Add KFENCE test to LKDTM (Stephen Boyd)

 - Various strncpy() refactorings (Justin Stitt)

 - Fix qnx4 to avoid writing into the smaller of two overlapping buffers

 - Various strlcpy() refactorings

* tag 'hardening-v6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  qnx4: Use get_directory_fname() in qnx4_match()
  qnx4: Extract dir entry filename processing into helper
  atags_proc: Add __counted_by for struct buffer and use struct_size()
  tracing/uprobe: Replace strlcpy() with strscpy()
  params: Fix multi-line comment style
  params: Sort headers
  params: Use size_add() for kmalloc()
  params: Do not go over the limit when getting the string length
  params: Introduce the param_unknown_fn type
  lkdtm: Add kfence read after free crash type
  nvme-fc: replace deprecated strncpy with strscpy
  nvdimm/btt: replace deprecated strncpy with strscpy
  nvme-fabrics: replace deprecated strncpy with strscpy
  drm/modes: replace deprecated strncpy with strscpy_pad
  afs: Add __counted_by for struct afs_acl and use struct_size()
  VMCI: Annotate struct vmci_handle_arr with __counted_by
  i40e: Annotate struct i40e_qvlist_info with __counted_by
  HID: uhid: replace deprecated strncpy with strscpy
  samples: Replace strlcpy() with strscpy()
  SUNRPC: Replace strlcpy() with strscpy()
 2024-01-10 11:03:52 -08:00
Breno Leitao
aefb2f2e61 x86/bugs: Rename CONFIG_RETPOLINE => CONFIG_MITIGATION_RETPOLINE 
Step 5/10 of the namespace unification of CPU mitigations related Kconfig options.

[ mingo: Converted a few more uses in comments/messages as well. ]

Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ariel Miculas <amiculas@cisco.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20231121160740.1249350-6-leitao@debian.org
 2024-01-10 10:52:28 +01:00
Steven Rostedt (Google)
25742aeb13 ring-buffer: Remove stale comment from ring_buffer_size() 
It's been 11 years since the ring_buffer_size() function was updated to
use the nr_pages from the buffer->buffers[cpu] structure instead of using
the buffer->nr_pages that no longer exists.

The comment in the code is more of what a change log should have and is
pretty much useless for development. It's saying how things worked back in
2012 that bares no purpose on today's code. Remove it.

Link: https://lore.kernel.org/linux-trace-kernel/84d3b41a72bd43dbb9d44921ef535c92@AcuMS.aculab.com/
Link: https://lore.kernel.org/linux-trace-kernel/20231220081028.7cd7e8e2@gandalf.local.home

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reported-by: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2024-01-09 22:54:37 -05:00
Linus Torvalds
5db8752c3b vfs-6.8.iov_iter 
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Merge tag 'vfs-6.8.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs iov_iter cleanups from Christian Brauner:
 "This contains a minor cleanup. The patches drop an unused argument
  from import_single_range() allowing to replace import_single_range()
  with import_ubuf() and dropping import_single_range() completely"

* tag 'vfs-6.8.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  iov_iter: replace import_single_range() with import_ubuf()
  iov_iter: remove unused 'iov' argument from import_single_range()
 2024-01-08 11:43:04 -08:00
Steven Rostedt (Google)
4f1991a92c tracing histograms: Simplify parse_actions() function 
The parse_actions() function uses 'len = str_has_prefix()' to test which
action is in the string being parsed. But then it goes and repeats the
logic for each different action. This logic can be simplified and
duplicate code can be removed as 'len' contains the length of the found
prefix which should be used for all actions.

Link: https://lore.kernel.org/all/20240107112044.6702cb66@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20240107203258.37e26d2b@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andy Shevchenko <andy@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2024-01-08 13:24:56 -05:00
Jakub Kicinski
e63c1822ac Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 
Cross-merge networking fixes after downstream PR.

Conflicts:

drivers/net/ethernet/broadcom/bnxt/bnxt.c
  e009b2efb7 ("bnxt_en: Remove mis-applied code from bnxt_cfg_ntp_filters()")
  0f2b214779 ("bnxt_en: Fix compile error without CONFIG_RFS_ACCEL")
https://lore.kernel.org/all/20240105115509.225aa8a2@canb.auug.org.au/

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2024-01-04 18:06:46 -08:00
Linus Torvalds
453f5db061 tracing fixes for v6.7-rc7: 
- Fix readers that are blocked on the ring buffer when buffer_percent is
   100%. They are supposed to wake up when the buffer is full, but
   because the sub-buffer that the writer is on is never considered
   "dirty" in the calculation, dirty pages will never equal nr_pages.
   Add +1 to the dirty count in order to count for the sub-buffer that
   the writer is on.
 
 - When a reader is blocked on the "snapshot_raw" file, it is to be
   woken up when a snapshot is done and be able to read the snapshot
   buffer. But because the snapshot swaps the buffers (the main one
   with the snapshot one), and the snapshot reader is waiting on the
   old snapshot buffer, it was not woken up (because it is now on
   the main buffer after the swap). Worse yet, when it reads the buffer
   after a snapshot, it's not reading the snapshot buffer, it's reading
   the live active main buffer.
 
   Fix this by forcing a wakeup of all readers on the snapshot buffer when
   a new snapshot happens, and then update the buffer that the reader
   is reading to be back on the snapshot buffer.
 
 - Fix the modification of the direct_function hash. There was a race
   when new functions were added to the direct_function hash as when
   it moved function entries from the old hash to the new one, a direct
   function trace could be hit and not see its entry.
 
   This is fixed by allocating the new hash, copy all the old entries
   onto it as well as the new entries, and then use rcu_assign_pointer()
   to update the new direct_function hash with it.
 
   This also fixes a memory leak in that code.
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Merge tag 'trace-v6.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Fix readers that are blocked on the ring buffer when buffer_percent
   is 100%. They are supposed to wake up when the buffer is full, but
   because the sub-buffer that the writer is on is never considered
   "dirty" in the calculation, dirty pages will never equal nr_pages.
   Add +1 to the dirty count in order to count for the sub-buffer that
   the writer is on.

 - When a reader is blocked on the "snapshot_raw" file, it is to be
   woken up when a snapshot is done and be able to read the snapshot
   buffer. But because the snapshot swaps the buffers (the main one with
   the snapshot one), and the snapshot reader is waiting on the old
   snapshot buffer, it was not woken up (because it is now on the main
   buffer after the swap). Worse yet, when it reads the buffer after a
   snapshot, it's not reading the snapshot buffer, it's reading the live
   active main buffer.

   Fix this by forcing a wakeup of all readers on the snapshot buffer
   when a new snapshot happens, and then update the buffer that the
   reader is reading to be back on the snapshot buffer.

 - Fix the modification of the direct_function hash. There was a race
   when new functions were added to the direct_function hash as when it
   moved function entries from the old hash to the new one, a direct
   function trace could be hit and not see its entry.

   This is fixed by allocating the new hash, copy all the old entries
   onto it as well as the new entries, and then use rcu_assign_pointer()
   to update the new direct_function hash with it.

   This also fixes a memory leak in that code.

 - Fix eventfs ownership

* tag 'trace-v6.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ftrace: Fix modification of direct_function hash while in use
  tracing: Fix blocked reader of snapshot buffer
  ring-buffer: Fix wake ups when buffer_percent is set to 100
  eventfs: Fix file and directory uid and gid ownership
 2023-12-30 11:37:35 -08:00
Steven Rostedt (Google)
d05cb47066 ftrace: Fix modification of direct_function hash while in use 
Masami Hiramatsu reported a memory leak in register_ftrace_direct() where
if the number of new entries are added is large enough to cause two
allocations in the loop:

        for (i = 0; i < size; i++) {
                hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
                        new = ftrace_add_rec_direct(entry->ip, addr, &free_hash);
                        if (!new)
                                goto out_remove;
                        entry->direct = addr;
                }
        }

Where ftrace_add_rec_direct() has:

        if (ftrace_hash_empty(direct_functions) ||
            direct_functions->count > 2 * (1 << direct_functions->size_bits)) {
                struct ftrace_hash *new_hash;
                int size = ftrace_hash_empty(direct_functions) ? 0 :
                        direct_functions->count + 1;

                if (size < 32)
                        size = 32;

                new_hash = dup_hash(direct_functions, size);
                if (!new_hash)
                        return NULL;

                *free_hash = direct_functions;
                direct_functions = new_hash;
        }

The "*free_hash = direct_functions;" can happen twice, losing the previous
allocation of direct_functions.

But this also exposed a more serious bug.

The modification of direct_functions above is not safe. As
direct_functions can be referenced at any time to find what direct caller
it should call, the time between:

                new_hash = dup_hash(direct_functions, size);
 and
                direct_functions = new_hash;

can have a race with another CPU (or even this one if it gets interrupted),
and the entries being moved to the new hash are not referenced.

That's because the "dup_hash()" is really misnamed and is really a
"move_hash()". It moves the entries from the old hash to the new one.

Now even if that was changed, this code is not proper as direct_functions
should not be updated until the end. That is the best way to handle
function reference changes, and is the way other parts of ftrace handles
this.

The following is done:

 1. Change add_hash_entry() to return the entry it created and inserted
    into the hash, and not just return success or not.

 2. Replace ftrace_add_rec_direct() with add_hash_entry(), and remove
    the former.

 3. Allocate a "new_hash" at the start that is made for holding both the
    new hash entries as well as the existing entries in direct_functions.

 4. Copy (not move) the direct_function entries over to the new_hash.

 5. Copy the entries of the added hash to the new_hash.

 6. If everything succeeds, then use rcu_pointer_assign() to update the
    direct_functions with the new_hash.

This simplifies the code and fixes both the memory leak as well as the
race condition mentioned above.

Link: https://lore.kernel.org/all/170368070504.42064.8960569647118388081.stgit@devnote2/
Link: https://lore.kernel.org/linux-trace-kernel/20231229115134.08dd5174@gandalf.local.home

Cc: stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Fixes: 763e34e74b ("ftrace: Add register_ftrace_direct()")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-30 10:07:27 -05:00
Steven Rostedt (Google)
39a7dc23a1 tracing: Fix blocked reader of snapshot buffer 
If an application blocks on the snapshot or snapshot_raw files, expecting
to be woken up when a snapshot occurs, it will not happen. Or it may
happen with an unexpected result.

That result is that the application will be reading the main buffer
instead of the snapshot buffer. That is because when the snapshot occurs,
the main and snapshot buffers are swapped. But the reader has a descriptor
still pointing to the buffer that it originally connected to.

This is fine for the main buffer readers, as they may be blocked waiting
for a watermark to be hit, and when a snapshot occurs, the data that the
main readers want is now on the snapshot buffer.

But for waiters of the snapshot buffer, they are waiting for an event to
occur that will trigger the snapshot and they can then consume it quickly
to save the snapshot before the next snapshot occurs. But to do this, they
need to read the new snapshot buffer, not the old one that is now
receiving new data.

Also, it does not make sense to have a watermark "buffer_percent" on the
snapshot buffer, as the snapshot buffer is static and does not receive new
data except all at once.

Link: https://lore.kernel.org/linux-trace-kernel/20231228095149.77f5b45d@gandalf.local.home

Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Fixes: debdd57f51 ("tracing: Make a snapshot feature available from userspace")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-29 09:18:49 -05:00
Steven Rostedt (Google)
623b1f896f ring-buffer: Fix wake ups when buffer_percent is set to 100 
The tracefs file "buffer_percent" is to allow user space to set a
water-mark on how much of the tracing ring buffer needs to be filled in
order to wake up a blocked reader.

 0 - is to wait until any data is in the buffer
 1 - is to wait for 1% of the sub buffers to be filled
 50 - would be half of the sub buffers are filled with data
 100 - is not to wake the waiter until the ring buffer is completely full

Unfortunately the test for being full was:

	dirty = ring_buffer_nr_dirty_pages(buffer, cpu);
	return (dirty * 100) > (full * nr_pages);

Where "full" is the value for "buffer_percent".

There is two issues with the above when full == 100.

1. dirty * 100 > 100 * nr_pages will never be true
   That is, the above is basically saying that if the user sets
   buffer_percent to 100, more pages need to be dirty than exist in the
   ring buffer!

2. The page that the writer is on is never considered dirty, as dirty
   pages are only those that are full. When the writer goes to a new
   sub-buffer, it clears the contents of that sub-buffer.

That is, even if the check was ">=" it would still not be equal as the
most pages that can be considered "dirty" is nr_pages - 1.

To fix this, add one to dirty and use ">=" in the compare.

Link: https://lore.kernel.org/linux-trace-kernel/20231226125902.4a057f1d@gandalf.local.home

Cc: stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Fixes: 03329f9939 ("tracing: Add tracefs file buffer_percentage")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-29 09:18:30 -05:00
Paolo Abeni
56794e5358 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 
Cross-merge networking fixes after downstream PR.

Adjacent changes:

drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
  23c93c3b62 ("bnxt_en: do not map packet buffers twice")
  6d1add9553 ("bnxt_en: Modify TX ring indexing logic.")

tools/testing/selftests/net/Makefile
  2258b66648 ("selftests: add vlan hw filter tests")
  a0bc96c0cd ("selftests: net: verify fq per-band packet limit")

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
 2023-12-21 22:17:23 +01:00
Linus Torvalds
13b734465a Tracing fixes for 6.7: 
- Fix another kerneldoc warning
 
 - Fix eventfs files to inherit the ownership of its parent directory.
   The dynamic creating of dentries in eventfs did not take into
   account if the tracefs file system was mounted with a gid/uid,
   and would still default to the gid/uid of root. This is a regression.
 
 - Fix warning when synthetic event testing is enabled along with
   startup event tracing testing is enabled
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Merge tag 'trace-v6.7-rc6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Fix another kerneldoc warning

 - Fix eventfs files to inherit the ownership of its parent directory.

   The dynamic creation of dentries in eventfs did not take into account
   if the tracefs file system was mounted with a gid/uid, and would
   still default to the gid/uid of root. This is a regression.

 - Fix warning when synthetic event testing is enabled along with
   startup event tracing testing is enabled

* tag 'trace-v6.7-rc6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing / synthetic: Disable events after testing in synth_event_gen_test_init()
  eventfs: Have event files and directories default to parent uid and gid
  tracing/synthetic: fix kernel-doc warnings
 2023-12-21 09:31:45 -08:00
Steven Rostedt (Google)
3cb3091138 ring-buffer: Use subbuf_order for buffer page masking 
The comparisons to PAGE_SIZE were all converted to use the
buffer->subbuf_order, but the use of PAGE_MASK was missed.

Convert all the PAGE_MASK usages over to:

  (PAGE_SIZE << cpu_buffer->buffer->subbuf_order) - 1

Link: https://lore.kernel.org/linux-trace-kernel/20231219173800.66eefb7a@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Fixes: 139f840021 ("ring-buffer: Page size per ring buffer")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-21 11:04:48 -05:00
Steven Rostedt (Google)
2f84b39f48 tracing: Update subbuffer with kilobytes not page order 
Using page order for deciding what the size of the ring buffer sub buffers
are is exposing a bit too much of the implementation. Although the sub
buffers are only allocated in orders of pages, allow the user to specify
the minimum size of each sub-buffer via kilobytes like they can with the
buffer size itself.

If the user specifies 3 via:

  echo 3 > buffer_subbuf_size_kb

Then the sub-buffer size will round up to 4kb (on a 4kb page size system).

If they specify:

  echo 6 > buffer_subbuf_size_kb

The sub-buffer size will become 8kb.

and so on.

Link: https://lore.kernel.org/linux-trace-kernel/20231219185631.809766769@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-21 11:04:15 -05:00
Steven Rostedt (Google)
8e7b58c27b ring-buffer: Just update the subbuffers when changing their allocation order 
The ring_buffer_subbuf_order_set() was creating ring_buffer_per_cpu
cpu_buffers with the new subbuffers with the updated order, and if they
all successfully were created, then they the ring_buffer's per_cpu buffers
would be freed and replaced by them.

The problem is that the freed per_cpu buffers contains state that would be
lost. Running the following commands:

1. # echo 3 > /sys/kernel/tracing/buffer_subbuf_order
2. # echo 0 > /sys/kernel/tracing/tracing_cpumask
3. # echo 1 > /sys/kernel/tracing/snapshot
4. # echo ff > /sys/kernel/tracing/tracing_cpumask
5. # echo test > /sys/kernel/tracing/trace_marker

Would result in:

 -bash: echo: write error: Bad file descriptor

That's because the state of the per_cpu buffers of the snapshot buffer is
lost when the order is changed (the order of a freed snapshot buffer goes
to 0 to save memory, and when the snapshot buffer is allocated again, it
goes back to what the main buffer is).

In operation 2, the snapshot buffers were set to "disable" (as all the
ring buffers CPUs were disabled).

In operation 3, the snapshot is allocated and a call to
ring_buffer_subbuf_order_set() replaced the per_cpu buffers losing the
"record_disable" count.

When it was enabled again, the atomic_dec(&cpu_buffer->record_disable) was
decrementing a zero, setting it to -1. Writing 1 into the snapshot would
swap the snapshot buffer with the main buffer, so now the main buffer is
"disabled", and nothing can write to the ring buffer anymore.

Instead of creating new per_cpu buffers and losing the state of the old
buffers, basically do what the resize does and just allocate new subbuf
pages into the new_pages link list of the per_cpu buffer and if they all
succeed, then replace the old sub buffers with the new ones. This keeps
the per_cpu buffer descriptor in tact and by doing so, keeps its state.

Link: https://lore.kernel.org/linux-trace-kernel/20231219185630.944104939@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Fixes: f9b94daa54 ("ring-buffer: Set new size of the ring buffer sub page")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-21 11:02:52 -05:00
Steven Rostedt (Google)
353cc21937 ring-buffer: Keep the same size when updating the order 
The function ring_buffer_subbuf_order_set() just updated the sub-buffers
to the new size, but this also changes the size of the buffer in doing so.
As the size is determined by nr_pages * subbuf_size. If the subbuf_size is
increased without decreasing the nr_pages, this causes the total size of
the buffer to increase.

This broke the latency tracers as the snapshot needs to be the same size
as the main buffer. The size of the snapshot buffer is only expanded when
needed, and because the order is still the same, the size becomes out of
sync with the main buffer, as the main buffer increased in size without
the tracing system knowing.

Calculate the nr_pages to allocate with the new subbuf_size to be
buffer_size / new_subbuf_size.

Link: https://lore.kernel.org/linux-trace-kernel/20231219185630.649397785@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Fixes: f9b94daa54 ("ring-buffer: Set new size of the ring buffer sub page")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-21 11:02:01 -05:00
Steven Rostedt (Google)
fa4b54af5b tracing: Stop the tracing while changing the ring buffer subbuf size 
Because the main buffer and the snapshot buffer need to be the same for
some tracers, otherwise it will fail and disable all tracing, the tracers
need to be stopped while updating the sub buffer sizes so that the tracers
see the main and snapshot buffers with the same sub buffer size.

Link: https://lore.kernel.org/linux-trace-kernel/20231219185630.353222794@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Fixes: 2808e31ec1 ("ring-buffer: Add interface for configuring trace sub buffer size")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-21 11:00:56 -05:00
Steven Rostedt (Google)
aa067682ad tracing: Update snapshot order along with main buffer order 
When updating the order of the sub buffers for the main buffer, make sure
that if the snapshot buffer exists, that it gets its order updated as
well.

Link: https://lore.kernel.org/linux-trace-kernel/20231219185630.054668186@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-21 10:55:57 -05:00
Steven Rostedt (Google)
4e958db34f ring-buffer: Make sure the spare sub buffer used for reads has same size 
Now that the ring buffer specifies the size of its sub buffers, they all
need to be the same size. When doing a read, a swap is done with a spare
page. Make sure they are the same size before doing the swap, otherwise
the read will fail.

Link: https://lore.kernel.org/linux-trace-kernel/20231219185629.763664788@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-21 10:55:04 -05:00
Steven Rostedt (Google)
b81e03a249 ring-buffer: Do no swap cpu buffers if order is different 
As all the subbuffer order (subbuffer sizes) must be the same throughout
the ring buffer, check the order of the buffers that are doing a CPU
buffer swap in ring_buffer_swap_cpu() to make sure they are the same.

If the are not the same, then fail to do the swap, otherwise the ring
buffer will think the CPU buffer has a specific subbuffer size when it
does not.

Link: https://lore.kernel.org/linux-trace-kernel/20231219185629.467894710@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-21 10:54:50 -05:00
Steven Rostedt (Google)
22887dfba0 ring-buffer: Clear pages on error in ring_buffer_subbuf_order_set() failure 
On failure to allocate ring buffer pages, the pointer to the CPU buffer
pages is freed, but the pages that were allocated previously were not.
Make sure they are freed too.

Link: https://lore.kernel.org/linux-trace-kernel/20231219185629.179352802@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Fixes: f9b94daa54 ("tracing: Set new size of the ring buffer sub page")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-21 10:53:59 -05:00
Steven Rostedt (Google)
88b30c7f5d tracing / synthetic: Disable events after testing in synth_event_gen_test_init() 
The synth_event_gen_test module can be built in, if someone wants to run
the tests at boot up and not have to load them.

The synth_event_gen_test_init() function creates and enables the synthetic
events and runs its tests.

The synth_event_gen_test_exit() disables the events it created and
destroys the events.

If the module is builtin, the events are never disabled. The issue is, the
events should be disable after the tests are run. This could be an issue
if the rest of the boot up tests are enabled, as they expect the events to
be in a known state before testing. That known state happens to be
disabled.

When CONFIG_SYNTH_EVENT_GEN_TEST=y and CONFIG_EVENT_TRACE_STARTUP_TEST=y
a warning will trigger:

 Running tests on trace events:
 Testing event create_synth_test:
 Enabled event during self test!
 ------------[ cut here ]------------
 WARNING: CPU: 2 PID: 1 at kernel/trace/trace_events.c:4150 event_trace_self_tests+0x1c2/0x480
 Modules linked in:
 CPU: 2 PID: 1 Comm: swapper/0 Not tainted 6.7.0-rc2-test-00031-gb803d7c664d5-dirty #276
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
 RIP: 0010:event_trace_self_tests+0x1c2/0x480
 Code: bb e8 a2 ab 5d fc 48 8d 7b 48 e8 f9 3d 99 fc 48 8b 73 48 40 f6 c6 01 0f 84 d6 fe ff ff 48 c7 c7 20 b6 ad bb e8 7f ab 5d fc 90 <0f> 0b 90 48 89 df e8 d3 3d 99 fc 48 8b 1b 4c 39 f3 0f 85 2c ff ff
 RSP: 0000:ffffc9000001fdc0 EFLAGS: 00010246
 RAX: 0000000000000029 RBX: ffff88810399ca80 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: ffffffffb9f19478 RDI: ffff88823c734e64
 RBP: ffff88810399f300 R08: 0000000000000000 R09: fffffbfff79eb32a
 R10: ffffffffbcf59957 R11: 0000000000000001 R12: ffff888104068090
 R13: ffffffffbc89f0a0 R14: ffffffffbc8a0f08 R15: 0000000000000078
 FS:  0000000000000000(0000) GS:ffff88823c700000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 00000001f6282001 CR4: 0000000000170ef0
 Call Trace:
  <TASK>
  ? __warn+0xa5/0x200
  ? event_trace_self_tests+0x1c2/0x480
  ? report_bug+0x1f6/0x220
  ? handle_bug+0x6f/0x90
  ? exc_invalid_op+0x17/0x50
  ? asm_exc_invalid_op+0x1a/0x20
  ? tracer_preempt_on+0x78/0x1c0
  ? event_trace_self_tests+0x1c2/0x480
  ? __pfx_event_trace_self_tests_init+0x10/0x10
  event_trace_self_tests_init+0x27/0xe0
  do_one_initcall+0xd6/0x3c0
  ? __pfx_do_one_initcall+0x10/0x10
  ? kasan_set_track+0x25/0x30
  ? rcu_is_watching+0x38/0x60
  kernel_init_freeable+0x324/0x450
  ? __pfx_kernel_init+0x10/0x10
  kernel_init+0x1f/0x1e0
  ? _raw_spin_unlock_irq+0x33/0x50
  ret_from_fork+0x34/0x60
  ? __pfx_kernel_init+0x10/0x10
  ret_from_fork_asm+0x1b/0x30
  </TASK>

This is because the synth_event_gen_test_init() left the synthetic events
that it created enabled. By having it disable them after testing, the
other selftests will run fine.

Link: https://lore.kernel.org/linux-trace-kernel/20231220111525.2f0f49b0@gandalf.local.home

Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 9fe41efaca ("tracing: Add synth event generation test module")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reported-by: Alexander Graf <graf@amazon.com>
Tested-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-21 10:04:45 -05:00
Randy Dunlap
7beb82b7d5 tracing/synthetic: fix kernel-doc warnings 
scripts/kernel-doc warns about using @args: for variadic arguments to
functions. Documentation/doc-guide/kernel-doc.rst says that this should
be written as @...: instead, so update the source code to match that,
preventing the warnings.

trace_events_synth.c:1165: warning: Excess function parameter 'args' description in '__synth_event_gen_cmd_start'
trace_events_synth.c:1714: warning: Excess function parameter 'args' description in 'synth_event_trace'

Link: https://lore.kernel.org/linux-trace-kernel/20231220061226.30962-1-rdunlap@infradead.org

Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 35ca5207c2 ("tracing: Add synthetic event command generation functions")
Fixes: 8dcc53ad95 ("tracing: Add synth_event_trace() and related functions")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-20 12:51:03 -05:00
Tzvetomir Stoyanov (VMware)
bce761d757 ring-buffer: Read and write to ring buffers with custom sub buffer size 
As the size of the ring sub buffer page can be changed dynamically,
the logic that reads and writes to the buffer should be fixed to take
that into account. Some internal ring buffer APIs are changed:
 ring_buffer_alloc_read_page()
 ring_buffer_free_read_page()
 ring_buffer_read_page()
A new API is introduced:
 ring_buffer_read_page_data()

Link: https://lore.kernel.org/linux-trace-devel/20211213094825.61876-6-tz.stoyanov@gmail.com
Link: https://lore.kernel.org/linux-trace-kernel/20231219185628.875145995@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
[ Fixed kerneldoc on data_page parameter in ring_buffer_free_read_page() ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-20 07:54:56 -05:00
Tzvetomir Stoyanov (VMware)
f9b94daa54 ring-buffer: Set new size of the ring buffer sub page 
There are two approaches when changing the size of the ring buffer
sub page:
 1. Destroying all pages and allocating new pages with the new size.
 2. Allocating new pages, copying the content of the old pages before
    destroying them.
The first approach is easier, it is selected in the proposed
implementation. Changing the ring buffer sub page size is supposed to
not happen frequently. Usually, that size should be set only once,
when the buffer is not in use yet and is supposed to be empty.

Link: https://lore.kernel.org/linux-trace-devel/20211213094825.61876-5-tz.stoyanov@gmail.com
Link: https://lore.kernel.org/linux-trace-kernel/20231219185628.588995543@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-20 07:54:56 -05:00
Tzvetomir Stoyanov (VMware)
2808e31ec1 ring-buffer: Add interface for configuring trace sub buffer size 
The trace ring buffer sub page size can be configured, per trace
instance. A new ftrace file "buffer_subbuf_order" is added to get and
set the size of the ring buffer sub page for current trace instance.
The size must be an order of system page size, that's why the new
interface works with system page order, instead of absolute page size:
0 means the ring buffer sub page is equal to 1 system page and so
forth:
0 - 1 system page
1 - 2 system pages
2 - 4 system pages
...
The ring buffer sub page size is limited between 1 and 128 system
pages. The default value is 1 system page.
New ring buffer APIs are introduced:
 ring_buffer_subbuf_order_set()
 ring_buffer_subbuf_order_get()
 ring_buffer_subbuf_size_get()

Link: https://lore.kernel.org/linux-trace-devel/20211213094825.61876-4-tz.stoyanov@gmail.com
Link: https://lore.kernel.org/linux-trace-kernel/20231219185628.298324722@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-20 07:54:55 -05:00
Tzvetomir Stoyanov (VMware)
139f840021 ring-buffer: Page size per ring buffer 
Currently the size of one sub buffer page is global for all buffers and
it is hard coded to one system page. In order to introduce configurable
ring buffer sub page size, the internal logic should be refactored to
work with sub page size per ring buffer.

Link: https://lore.kernel.org/linux-trace-devel/20211213094825.61876-3-tz.stoyanov@gmail.com
Link: https://lore.kernel.org/linux-trace-kernel/20231219185628.009147038@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-20 07:54:55 -05:00
Tzvetomir Stoyanov (VMware)
d5cfbdfc96 ring-buffer: Have ring_buffer_print_page_header() be able to access ring_buffer_iter 
In order to introduce sub-buffer size per ring buffer, some internal
refactoring is needed. As ring_buffer_print_page_header() will depend on
the trace_buffer structure, it is moved after the structure definition.

Link: https://lore.kernel.org/linux-trace-devel/20211213094825.61876-2-tz.stoyanov@gmail.com
Link: https://lore.kernel.org/linux-trace-kernel/20231219185627.723857541@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-20 07:52:47 -05:00
Linus Torvalds
55cb5f4368 tracing fix for 6.7-rc6 
While working on the ring buffer, I found one more bug with the timestamp
 code, and the fix for this removed the need for the final 64-bit cmpxchg!
 
 The ring buffer events hold a "delta" from the previous event. If it is
 determined that the delta can not be calculated, it falls back to adding an
 absolute timestamp value. The way to know if the delta can be used is via
 two stored timestamps in the per-cpu buffer meta data:
 
  before_stamp and write_stamp
 
 The before_stamp is written by every event before it tries to allocate its
 space on the ring buffer. The write_stamp is written after it allocates its
 space and knows that nothing came in after it read the previous
 before_stamp and write_stamp and the two matched.
 
 A previous fix dd93942570 ("ring-buffer: Do not try to put back
 write_stamp") removed putting back the write_stamp to match the
 before_stamp so that the next event could use the delta, but races were
 found where the two would match, but not be for of the previous event.
 
 It was determined to allow the event reservation to not have a valid
 write_stamp when it is finished, and this fixed a lot of races.
 
 The last use of the 64-bit timestamp cmpxchg depended on the write_stamp
 being valid after an interruption. But this is no longer the case, as if an
 event is interrupted by a softirq that writes an event, and that event gets
 interrupted by a hardirq or NMI and that writes an event, then the softirq
 could finish its reservation without a valid write_stamp.
 
 In the slow path of the event reservation, a delta can still be used if the
 write_stamp is valid. Instead of using a cmpxchg against the write stamp,
 the before_stamp needs to be read again to validate the write_stamp. The
 cmpxchg is not needed.
 
 This updates the slowpath to validate the write_stamp by comparing it to
 the before_stamp and removes all rb_time_cmpxchg() as there are no more
 users of that function.
 
 The removal of the 32-bit updates of rb_time_t will be done in the next
 merge window.
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Merge tag 'trace-v6.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fix from Steven Rostedt:
 "While working on the ring buffer, I found one more bug with the
  timestamp code, and the fix for this removed the need for the final
  64-bit cmpxchg!

  The ring buffer events hold a "delta" from the previous event. If it
  is determined that the delta can not be calculated, it falls back to
  adding an absolute timestamp value. The way to know if the delta can
  be used is via two stored timestamps in the per-cpu buffer meta data:

   before_stamp and write_stamp

  The before_stamp is written by every event before it tries to allocate
  its space on the ring buffer. The write_stamp is written after it
  allocates its space and knows that nothing came in after it read the
  previous before_stamp and write_stamp and the two matched.

  A previous fix dd93942570 ("ring-buffer: Do not try to put back
  write_stamp") removed putting back the write_stamp to match the
  before_stamp so that the next event could use the delta, but races
  were found where the two would match, but not be for of the previous
  event.

  It was determined to allow the event reservation to not have a valid
  write_stamp when it is finished, and this fixed a lot of races.

  The last use of the 64-bit timestamp cmpxchg depended on the
  write_stamp being valid after an interruption. But this is no longer
  the case, as if an event is interrupted by a softirq that writes an
  event, and that event gets interrupted by a hardirq or NMI and that
  writes an event, then the softirq could finish its reservation without
  a valid write_stamp.

  In the slow path of the event reservation, a delta can still be used
  if the write_stamp is valid. Instead of using a cmpxchg against the
  write stamp, the before_stamp needs to be read again to validate the
  write_stamp. The cmpxchg is not needed.

  This updates the slowpath to validate the write_stamp by comparing it
  to the before_stamp and removes all rb_time_cmpxchg() as there are no
  more users of that function.

  The removal of the 32-bit updates of rb_time_t will be done in the
  next merge window"

* tag 'trace-v6.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Fix slowpath of interrupted event
 2023-12-19 12:25:43 -08:00
Andrii Nakryiko
d17aff807f Revert BPF token-related functionality 
This patch includes the following revert (one  conflicting BPF FS
patch and three token patch sets, represented by merge commits):
  - revert 0f5d5454c7 "Merge branch 'bpf-fs-mount-options-parsing-follow-ups'";
  - revert 750e785796 "bpf: Support uid and gid when mounting bpffs";
  - revert 733763285a "Merge branch 'bpf-token-support-in-libbpf-s-bpf-object'";
  - revert c35919dcce "Merge branch 'bpf-token-and-bpf-fs-based-delegation'".

Link: https://lore.kernel.org/bpf/CAHk-=wg7JuFYwGy=GOMbRCtOL+jwSQsdUaBsRWkDVYbxipbM5A@mail.gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
 2023-12-19 08:23:03 -08:00
Steven Rostedt (Google)
f50345b49b ring-buffer: Check if absolute timestamp goes backwards 
The check_buffer() which checks the timestamps of the ring buffer
sub-buffer page, when enabled, only checks if the adding of deltas of the
events from the last absolute timestamp or the timestamp of the sub-buffer
page adds up to the current event.

What it does not check is if the absolute timestamp causes the time of the
events to go backwards, as that can cause issues elsewhere.

Test for the timestamp going backwards too.

This also fixes a slight issue where if the warning triggers at boot up
(because of the resetting of the tsc), it will disable all further checks,
even those that are after boot Have it continue checking if the warning
was ignored during boot up.

Link: https://lore.kernel.org/linux-trace-kernel/20231219074732.18b092d4@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-19 07:49:47 -05:00
Steven Rostedt (Google)
d40dbb617a ring-buffer: Add interrupt information to dump of data sub-buffer 
When the ring buffer timestamp verifier triggers, it dumps the content of
the sub-buffer. But currently it only dumps the timestamps and the offset
of the data as well as the deltas. It would be even more informative if
the event data also showed the interrupt context level it was in.

That is, if each event showed that the event was written in normal,
softirq, irq or NMI context. Then a better idea about how the events may
have been interrupted from each other.

As the payload of the ring buffer is really a black box of the ring
buffer, just assume that if the payload is larger than a trace entry, that
it is a trace entry. As trace entries have the interrupt context
information saved in a flags field, look at that location and report the
output of the flags.

If the payload is not a trace entry, there's no way to really know, and
the information will be garbage. But that's OK, because this is for
debugging only (this output is not used in production as the buffer check
that calls it causes a huge overhead to the tracing). This information,
when available, is crucial for debugging timestamp issues. If it's
garbage, it will also be pretty obvious that its garbage too.

As this output usually happens in kselftests of the tracing code, the user
will know what the payload is at the time.

Link: https://lore.kernel.org/linux-trace-kernel/20231219074542.6f304601@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Suggested-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-19 07:49:22 -05:00
Steven Rostedt (Google)
c84897c0ff ring-buffer: Remove 32bit timestamp logic 
Each event has a 27 bit timestamp delta that is used to hold the delta
from the last event. If the time between events is greater than 2^27, then
a timestamp is added that holds a 59 bit absolute timestamp.

Until a389d86f7f ("ring-buffer: Have nested events still record running
time stamp"), if an interrupt interrupted an event in progress, all the
events delta would be zero to not deal with the races that need to be
handled. The commit a389d86f7f changed that to handle the races giving
all events, even those that preempt other events, still have an accurate
timestamp.

To handle those races requires performing 64-bit cmpxchg on the
timestamps. But doing 64-bit cmpxchg on 32-bit architectures is considered
very slow. To try to deal with this the timestamp logic was broken into
two and then three 32-bit cmpxchgs, with the thought that two (or three)
32-bit cmpxchgs are still faster than a single 64-bit cmpxchg on 32-bit
architectures.

Part of the problem with this is that I didn't have any 32-bit
architectures to test on. After hitting several subtle bugs in this code,
an effort was made to try and see if three 32-bit cmpxchgs are indeed
faster than a single 64-bit. After a few people brushed off the dust of
their old 32-bit machines, tests were done, and even though 32-bit cmpxchg
was faster than a single 64-bit, it was in the order of 50% at best, not
300%.

After some more refactoring of the code, all 4 64-bit cmpxchg were removed:

 https://lore.kernel.org/linux-trace-kernel/20231211114420.36dde01b@gandalf.local.home
 https://lore.kernel.org/linux-trace-kernel/20231214222921.193037a7@gandalf.local.home
 https://lore.kernel.org/linux-trace-kernel/20231215081810.1f4f38fe@rorschach.local.home
 https://lore.kernel.org/linux-trace-kernel/20231218230712.3a76b081@gandalf.local.home/

With all the 64-bit cmpxchg removed, the complex 32-bit workaround can also be
removed.

The 32-bit and 64-bit logic is now exactly the same.

Link: https://lore.kernel.org/all/20231213214632.15047c40@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20231219074303.28f9abda@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-19 07:47:04 -05:00
Steven Rostedt (Google)
76ca20c748 tracing: Increase size of trace_marker_raw to max ring buffer entry 
There's no reason to give an arbitrary limit to the size of a raw trace
marker. Just let it be as big as the size that is allowed by the ring
buffer itself.

And there's also no reason to artificially break up the write to
TRACE_BUF_SIZE, as that's not even used.

Link: https://lore.kernel.org/linux-trace-kernel/20231213104218.2efc70c1@gandalf.local.home

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-18 23:14:16 -05:00
Steven Rostedt (Google)
9482341d9b tracing: Have trace_marker break up by lines by size of trace_seq 
If a trace_marker write is bigger than what trace_seq can hold, then it
will print "LINE TOO BIG" message and not what was written.

Instead, check if the write is bigger than the trace_seq and break it
up by that size.

Ideally, we could make the trace_seq dynamic that could hold this. But
that's for another time.

Link: https://lore.kernel.org/linux-trace-kernel/20231212190422.1eaf224f@gandalf.local.home

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-18 23:14:16 -05:00
Steven Rostedt (Google)
40fc60e36c trace_seq: Increase the buffer size to almost two pages 
Now that trace_marker can hold more than 1KB string, and can write as much
as the ring buffer can hold, the trace_seq is not big enough to hold
writes:

 ~# a="1234567890"
 ~# cnt=4080
 ~# s=""
 ~# while [ $cnt -gt 10 ]; do
 ~#	s="${s}${a}"
 ~#	cnt=$((cnt-10))
 ~# done
 ~# echo $s > trace_marker
 ~# cat trace
 # tracer: nop
 #
 # entries-in-buffer/entries-written: 2/2   #P:8
 #
 #                                _-----=> irqs-off/BH-disabled
 #                               / _----=> need-resched
 #                              | / _---=> hardirq/softirq
 #                              || / _--=> preempt-depth
 #                              ||| / _-=> migrate-disable
 #                              |||| /     delay
 #           TASK-PID     CPU#  |||||  TIMESTAMP  FUNCTION
 #              | |         |   |||||     |         |
            <...>-860     [002] .....   105.543465: tracing_mark_write[LINE TOO BIG]
            <...>-860     [002] .....   105.543496: tracing_mark_write: 789012345678901234567890

By increasing the trace_seq buffer to almost two pages, it can now print
out the first line.

This also subtracts the rest of the trace_seq fields from the buffer, so
that the entire trace_seq is now PAGE_SIZE aligned.

Link: https://lore.kernel.org/linux-trace-kernel/20231209175220.19867af4@gandalf.local.home

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-18 23:14:16 -05:00
Steven Rostedt (Google)
8ec90be7f1 tracing: Allow for max buffer data size trace_marker writes 
Allow a trace write to be as big as the ring buffer tracing data will
allow. Currently, it only allows writes of 1KB in size, but there's no
reason that it cannot allow what the ring buffer can hold.

Link: https://lore.kernel.org/linux-trace-kernel/20231212131901.5f501e72@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-18 23:14:16 -05:00
Steven Rostedt (Google)
0b9036efd8 ring-buffer: Add offset of events in dump on mismatch 
On bugs that have the ring buffer timestamp get out of sync, the config
CONFIG_RING_BUFFER_VALIDATE_TIME_DELTAS, that checks for it and if it is
detected it causes a dump of the bad sub buffer.

It shows each event and their timestamp as well as the delta in the event.
But it's also good to see the offset into the subbuffer for that event to
know if how close to the end it is.

Also print where the last event actually ended compared to where it was
expected to end.

Link: https://lore.kernel.org/linux-trace-kernel/20231211131623.59eaebd2@gandalf.local.home

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-18 23:14:16 -05:00
Steven Rostedt (Google)
d23569979c tracing: Allow creating instances with specified system events 
A trace instance may only need to enable specific events. As the eventfs
directory of an instance currently creates all events which adds overhead,
allow internal instances to be created with just the events in systems
that they care about. This currently only deals with systems and not
individual events, but this should bring down the overhead of creating
instances for specific use cases quite bit.

The trace_array_get_by_name() now has another parameter "systems". This
parameter is a const string pointer of a comma/space separated list of
event systems that should be created by the trace_array. (Note if the
trace_array already exists, this parameter is ignored).

The list of systems is saved and if a module is loaded, its events will
not be added unless the system for those events also match the systems
string.

Link: https://lore.kernel.org/linux-trace-kernel/20231213093701.03fddec0@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Arun Easi   <aeasi@marvell.com>
Cc: Daniel Wagner <dwagner@suse.de>
Tested-by: Dmytro Maluka <dmaluka@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-18 23:14:16 -05:00
Steven Rostedt (Google)
b803d7c664 ring-buffer: Fix slowpath of interrupted event 
To synchronize the timestamps with the ring buffer reservation, there are
two timestamps that are saved in the buffer meta data.

1. before_stamp
2. write_stamp

When the two are equal, the write_stamp is considered valid, as in, it may
be used to calculate the delta of the next event as the write_stamp is the
timestamp of the previous reserved event on the buffer.

This is done by the following:

 /*A*/	w = current position on the ring buffer
	before = before_stamp
	after = write_stamp
	ts = read current timestamp

	if (before != after) {
		write_stamp is not valid, force adding an absolute
		timestamp.
	}

 /*B*/	before_stamp = ts

 /*C*/	write = local_add_return(event length, position on ring buffer)

	if (w == write - event length) {
		/* Nothing interrupted between A and C */
 /*E*/		write_stamp = ts;
		delta = ts - after
		/*
		 * If nothing interrupted again,
		 * before_stamp == write_stamp and write_stamp
		 * can be used to calculate the delta for
		 * events that come in after this one.
		 */
	} else {

		/*
		 * The slow path!
		 * Was interrupted between A and C.
		 */

This is the place that there's a bug. We currently have:

		after = write_stamp
		ts = read current timestamp

 /*F*/		if (write == current position on the ring buffer &&
		    after < ts && cmpxchg(write_stamp, after, ts)) {

			delta = ts - after;

		} else {
			delta = 0;
		}

The assumption is that if the current position on the ring buffer hasn't
moved between C and F, then it also was not interrupted, and that the last
event written has a timestamp that matches the write_stamp. That is the
write_stamp is valid.

But this may not be the case:

If a task context event was interrupted by softirq between B and C.

And the softirq wrote an event that got interrupted by a hard irq between
C and E.

and the hard irq wrote an event (does not need to be interrupted)

We have:

 /*B*/ before_stamp = ts of normal context

   ---> interrupted by softirq

	/*B*/ before_stamp = ts of softirq context

	  ---> interrupted by hardirq

		/*B*/ before_stamp = ts of hard irq context
		/*E*/ write_stamp = ts of hard irq context

		/* matches and write_stamp valid */
	  <----

	/*E*/ write_stamp = ts of softirq context

	/* No longer matches before_stamp, write_stamp is not valid! */

   <---

 w != write - length, go to slow path

// Right now the order of events in the ring buffer is:
//
// |-- softirq event --|-- hard irq event --|-- normal context event --|
//

 after = write_stamp (this is the ts of softirq)
 ts = read current timestamp

 if (write == current position on the ring buffer [true] &&
     after < ts [true] && cmpxchg(write_stamp, after, ts) [true]) {

	delta = ts - after  [Wrong!]

The delta is to be between the hard irq event and the normal context
event, but the above logic made the delta between the softirq event and
the normal context event, where the hard irq event is between the two. This
will shift all the remaining event timestamps on the sub-buffer
incorrectly.

The write_stamp is only valid if it matches the before_stamp. The cmpxchg
does nothing to help this.

Instead, the following logic can be done to fix this:

	before = before_stamp
	ts = read current timestamp
	before_stamp = ts

	after = write_stamp

	if (write == current position on the ring buffer &&
	    after == before && after < ts) {

		delta = ts - after

	} else {
		delta = 0;
	}

The above will only use the write_stamp if it still matches before_stamp
and was tested to not have changed since C.

As a bonus, with this logic we do not need any 64-bit cmpxchg() at all!

This means the 32-bit rb_time_t workaround can finally be removed. But
that's for a later time.

Link: https://lore.kernel.org/linux-trace-kernel/20231218175229.58ec3daf@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20231218230712.3a76b081@gandalf.local.home

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: dd93942570 ("ring-buffer: Do not try to put back write_stamp")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 2023-12-18 23:12:22 -05:00
Jakub Kicinski
c49b292d03 netdev 
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Alexei Starovoitov says:

====================
pull-request: bpf-next 2023-12-18

This PR is larger than usual and contains changes in various parts
of the kernel.

The main changes are:

1) Fix kCFI bugs in BPF, from Peter Zijlstra.

End result: all forms of indirect calls from BPF into kernel
and from kernel into BPF work with CFI enabled. This allows BPF
to work with CONFIG_FINEIBT=y.

2) Introduce BPF token object, from Andrii Nakryiko.

It adds an ability to delegate a subset of BPF features from privileged
daemon (e.g., systemd) through special mount options for userns-bound
BPF FS to a trusted unprivileged application. The design accommodates
suggestions from Christian Brauner and Paul Moore.

Example:
$ sudo mkdir -p /sys/fs/bpf/token
$ sudo mount -t bpf bpffs /sys/fs/bpf/token \
             -o delegate_cmds=prog_load:MAP_CREATE \
             -o delegate_progs=kprobe \
             -o delegate_attachs=xdp

3) Various verifier improvements and fixes, from Andrii Nakryiko, Andrei Matei.

 - Complete precision tracking support for register spills
 - Fix verification of possibly-zero-sized stack accesses
 - Fix access to uninit stack slots
 - Track aligned STACK_ZERO cases as imprecise spilled registers.
   It improves the verifier "instructions processed" metric from single
   digit to 50-60% for some programs.
 - Fix verifier retval logic

4) Support for VLAN tag in XDP hints, from Larysa Zaremba.

5) Allocate BPF trampoline via bpf_prog_pack mechanism, from Song Liu.

End result: better memory utilization and lower I$ miss for calls to BPF
via BPF trampoline.

6) Fix race between BPF prog accessing inner map and parallel delete,
from Hou Tao.

7) Add bpf_xdp_get_xfrm_state() kfunc, from Daniel Xu.

It allows BPF interact with IPSEC infra. The intent is to support
software RSS (via XDP) for the upcoming ipsec pcpu work.
Experiments on AWS demonstrate single tunnel pcpu ipsec reaching
line rate on 100G ENA nics.

8) Expand bpf_cgrp_storage to support cgroup1 non-attach, from Yafang Shao.

9) BPF file verification via fsverity, from Song Liu.

It allows BPF progs get fsverity digest.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (164 commits)
  bpf: Ensure precise is reset to false in __mark_reg_const_zero()
  selftests/bpf: Add more uprobe multi fail tests
  bpf: Fail uprobe multi link with negative offset
  selftests/bpf: Test the release of map btf
  s390/bpf: Fix indirect trampoline generation
  selftests/bpf: Temporarily disable dummy_struct_ops test on s390
  x86/cfi,bpf: Fix bpf_exception_cb() signature
  bpf: Fix dtor CFI
  cfi: Add CFI_NOSEAL()
  x86/cfi,bpf: Fix bpf_struct_ops CFI
  x86/cfi,bpf: Fix bpf_callback_t CFI
  x86/cfi,bpf: Fix BPF JIT call
  cfi: Flip headers
  selftests/bpf: Add test for abnormal cnt during multi-kprobe attachment
  selftests/bpf: Don't use libbpf_get_error() in kprobe_multi_test
  selftests/bpf: Add test for abnormal cnt during multi-uprobe attachment
  bpf: Limit the number of kprobes when attaching program to multiple kprobes
  bpf: Limit the number of uprobes when attaching program to multiple uprobes
  bpf: xdp: Register generic_kfunc_set with XDP programs
  selftests/bpf: utilize string values for delegate_xxx mount options
  ...
====================

Link: https://lore.kernel.org/r/20231219000520.34178-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 2023-12-18 16:46:08 -08:00
Jiri Olsa
3983c00281 bpf: Fail uprobe multi link with negative offset 
Currently the __uprobe_register will return 0 (success) when called with
negative offset. The reason is that the call to register_for_each_vma and
then build_map_info won't return error for negative offset. They just won't
do anything - no matching vma is found so there's no registered breakpoint
for the uprobe.

I don't think we can change the behaviour of __uprobe_register and fail
for negative uprobe offset, because apps might depend on that already.

But I think we can still make the change and check for it on bpf multi
link syscall level.

Also moving the __get_user call and check for the offsets to the top of
loop, to fail early without extra __get_user calls for ref_ctr_offset
and cookie arrays.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/bpf/20231217215538.3361991-2-jolsa@kernel.org
 2023-12-18 09:51:30 -08:00
Naveen N Rao
9c556b7c3f trace/kprobe: Display the actual notrace function when rejecting a probe 
Trying to probe update_sd_lb_stats() using perf results in the below
message in the kernel log:
	trace_kprobe: Could not probe notrace function _text

This is because 'perf probe' specifies the kprobe location as an offset
from '_text':
	$ sudo perf probe -D update_sd_lb_stats
	p:probe/update_sd_lb_stats _text+1830728

However, the error message is misleading and doesn't help convey the
actual notrace function that is being probed. Fix this by looking up the
actual function name that is being probed. With this fix, we now get the
below message in the kernel log:
	trace_kprobe: Could not probe notrace function update_sd_lb_stats.constprop.0

Link: https://lore.kernel.org/all/20231214051702.1687300-1-naveen@kernel.org/

Signed-off-by: Naveen N Rao <naveen@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
 2023-12-17 16:28:54 +09:00
Linus Torvalds
3b8a9b2e68 Tracing fixes for v6.7-rc5: 
- Fix eventfs to check creating new files for events with names greater than
   NAME_MAX. The eventfs lookup needs to check the return result of
   simple_lookup().
 
 - Fix the ring buffer to check the proper max data size. Events must be able to
   fit on the ring buffer sub-buffer, if it cannot, then it fails to be written
   and the logic to add the event is avoided. The code to check if an event can
   fit failed to add the possible absolute timestamp which may make the event
   not be able to fit. This causes the ring buffer to go into an infinite loop
   trying to find a sub-buffer that would fit the event. Luckily, there's a check
   that will bail out if it looped over a 1000 times and it also warns.
 
   The real fix is not to add the absolute timestamp to an event that is
   starting at the beginning of a sub-buffer because it uses the sub-buffer
   timestamp. By avoiding the timestamp at the start of the sub-buffer allows
   events that pass the first check to always find a sub-buffer that it can fit
   on.
 
 - Have large events that do not fit on a trace_seq to print "LINE TOO BIG" like
   it does for the trace_pipe instead of what it does now which is to silently
   drop the output.
 
 - Fix a memory leak of forgetting to free the spare page that is saved by a
   trace instance.
 
 - Update the size of the snapshot buffer when the main buffer is updated if the
   snapshot buffer is allocated.
 
 - Fix ring buffer timestamp logic by removing all the places that tried to put
   the before_stamp back to the write stamp so that the next event doesn't add
   an absolute timestamp. But each of these updates added a race where by making
   the two timestamp equal, it was validating the write_stamp so that it can be
   incorrectly used for calculating the delta of an event.
 
 - There's a temp buffer used for printing the event that was using the event
   data size for allocation when it needed to use the size of the entire event
   (meta-data and payload data)
 
 - For hardening, use "%.*s" for printing the trace_marker output, to limit the
   amount that is printed by the size of the event. This was discovered by
   development that added a bug that truncated the '\0' and caused a crash.
 
 - Fix a use-after-free bug in the use of the histogram files when an instance
   is being removed.
 
 - Remove a useless update in the rb_try_to_discard of the write_stamp. The
   before_stamp was already changed to force the next event to add an absolute
   timestamp that the write_stamp is not used. But the write_stamp is modified
   again using an unneeded 64-bit cmpxchg.
 
 - Fix several races in the 32-bit implementation of the rb_time_cmpxchg() that
   does a 64-bit cmpxchg.
 
 - While looking at fixing the 64-bit cmpxchg, I noticed that because the ring
   buffer uses normal cmpxchg, and this can be done in NMI context, there's some
   architectures that do not have a working cmpxchg in NMI context. For these
   architectures, fail recording events that happen in NMI context.
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Merge tag 'trace-v6.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Fix eventfs to check creating new files for events with names greater
   than NAME_MAX. The eventfs lookup needs to check the return result of
   simple_lookup().

 - Fix the ring buffer to check the proper max data size. Events must be
   able to fit on the ring buffer sub-buffer, if it cannot, then it
   fails to be written and the logic to add the event is avoided. The
   code to check if an event can fit failed to add the possible absolute
   timestamp which may make the event not be able to fit. This causes
   the ring buffer to go into an infinite loop trying to find a
   sub-buffer that would fit the event. Luckily, there's a check that
   will bail out if it looped over a 1000 times and it also warns.

   The real fix is not to add the absolute timestamp to an event that is
   starting at the beginning of a sub-buffer because it uses the
   sub-buffer timestamp.

   By avoiding the timestamp at the start of the sub-buffer allows
   events that pass the first check to always find a sub-buffer that it
   can fit on.

 - Have large events that do not fit on a trace_seq to print "LINE TOO
   BIG" like it does for the trace_pipe instead of what it does now
   which is to silently drop the output.

 - Fix a memory leak of forgetting to free the spare page that is saved
   by a trace instance.

 - Update the size of the snapshot buffer when the main buffer is
   updated if the snapshot buffer is allocated.

 - Fix ring buffer timestamp logic by removing all the places that tried
   to put the before_stamp back to the write stamp so that the next
   event doesn't add an absolute timestamp. But each of these updates
   added a race where by making the two timestamp equal, it was
   validating the write_stamp so that it can be incorrectly used for
   calculating the delta of an event.

 - There's a temp buffer used for printing the event that was using the
   event data size for allocation when it needed to use the size of the
   entire event (meta-data and payload data)

 - For hardening, use "%.*s" for printing the trace_marker output, to
   limit the amount that is printed by the size of the event. This was
   discovered by development that added a bug that truncated the '\0'
   and caused a crash.

 - Fix a use-after-free bug in the use of the histogram files when an
   instance is being removed.

 - Remove a useless update in the rb_try_to_discard of the write_stamp.
   The before_stamp was already changed to force the next event to add
   an absolute timestamp that the write_stamp is not used. But the
   write_stamp is modified again using an unneeded 64-bit cmpxchg.

 - Fix several races in the 32-bit implementation of the
   rb_time_cmpxchg() that does a 64-bit cmpxchg.

 - While looking at fixing the 64-bit cmpxchg, I noticed that because
   the ring buffer uses normal cmpxchg, and this can be done in NMI
   context, there's some architectures that do not have a working
   cmpxchg in NMI context. For these architectures, fail recording
   events that happen in NMI context.

* tag 'trace-v6.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Do not record in NMI if the arch does not support cmpxchg in NMI
  ring-buffer: Have rb_time_cmpxchg() set the msb counter too
  ring-buffer: Fix 32-bit rb_time_read() race with rb_time_cmpxchg()
  ring-buffer: Fix a race in rb_time_cmpxchg() for 32 bit archs
  ring-buffer: Remove useless update to write_stamp in rb_try_to_discard()
  ring-buffer: Do not try to put back write_stamp
  tracing: Fix uaf issue when open the hist or hist_debug file
  tracing: Add size check when printing trace_marker output
  ring-buffer: Have saved event hold the entire event
  ring-buffer: Do not update before stamp when switching sub-buffers
  tracing: Update snapshot buffer on resize if it is allocated
  ring-buffer: Fix memory leak of free page
  eventfs: Fix events beyond NAME_MAX blocking tasks
  tracing: Have large events show up as '[LINE TOO BIG]' instead of nothing
  ring-buffer: Fix writing to the buffer with max_data_size
 2023-12-16 10:40:51 -08:00
Hou Tao
d6d1e6c17c bpf: Limit the number of kprobes when attaching program to multiple kprobes 
An abnormally big cnt may also be assigned to kprobe_multi.cnt when
attaching multiple kprobes. It will trigger the following warning in
kvmalloc_node():

	if (unlikely(size > INT_MAX)) {
	    WARN_ON_ONCE(!(flags & __GFP_NOWARN));
	    return NULL;
	}

Fix the warning by limiting the maximal number of kprobes in
bpf_kprobe_multi_link_attach(). If the number of kprobes is greater than
MAX_KPROBE_MULTI_CNT, the attachment will fail and return -E2BIG.

Fixes: 0dcac27254 ("bpf: Add multi kprobe link")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20231215100708.2265609-3-houtao@huaweicloud.com
 2023-12-15 22:54:55 +01:00
Hou Tao
8b2efe51ba bpf: Limit the number of uprobes when attaching program to multiple uprobes 
An abnormally big cnt may be passed to link_create.uprobe_multi.cnt,
and it will trigger the following warning in kvmalloc_node():

	if (unlikely(size > INT_MAX)) {
		WARN_ON_ONCE(!(flags & __GFP_NOWARN));
		return NULL;
	}

Fix the warning by limiting the maximal number of uprobes in
bpf_uprobe_multi_link_attach(). If the number of uprobes is greater than
MAX_UPROBE_MULTI_CNT, the attachment will return -E2BIG.

Fixes: 89ae89f53d ("bpf: Add multi uprobe link")
Reported-by: Xingwei Lee <xrivendell7@gmail.com>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Closes: https://lore.kernel.org/bpf/CABOYnLwwJY=yFAGie59LFsUsBAgHfroVqbzZ5edAXbFE3YiNVA@mail.gmail.com
Link: https://lore.kernel.org/bpf/20231215100708.2265609-2-houtao@huaweicloud.com
 2023-12-15 22:54:46 +01:00