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lf-6.6.y
3113 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Andrii Nakryiko
|
22db41226b |
bpf: Inline map creation logic in map_create() function
Currently find_and_alloc_map() performs two separate functions: some argument sanity checking and partial map creation workflow hanling. Neither of those functions are self-sufficient and are augmented by further checks and initialization logic in the caller (map_create() function). So unify all the sanity checks, permission checks, and creation and initialization logic in one linear piece of code in map_create() instead. This also make it easier to further enhance permission checks and keep them located in one place. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20230613223533.3689589-3-andrii@kernel.org |
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Andrii Nakryiko
|
1d28635abc |
bpf: Move unprivileged checks into map_create() and bpf_prog_load()
Make each bpf() syscall command a bit more self-contained, making it easier to further enhance it. We move sysctl_unprivileged_bpf_disabled handling down to map_create() and bpf_prog_load(), two special commands in this regard. Also swap the order of checks, calling bpf_capable() only if sysctl_unprivileged_bpf_disabled is true, avoiding unnecessary audit messages. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20230613223533.3689589-2-andrii@kernel.org |
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Sebastian Andrzej Siewior
|
ab5d47bd41 |
bpf: Remove in_atomic() from bpf_link_put().
bpf_free_inode() is invoked as a RCU callback. Usually RCU callbacks are invoked within softirq context. By setting rcutree.use_softirq=0 boot option the RCU callbacks will be invoked in a per-CPU kthread with bottom halves disabled which implies a RCU read section. On PREEMPT_RT the context remains fully preemptible. The RCU read section however does not allow schedule() invocation. The latter happens in mutex_lock() performed by bpf_trampoline_unlink_prog() originated from bpf_link_put(). It was pointed out that the bpf_link_put() invocation should not be delayed if originated from close(). It was also pointed out that other invocations from within a syscall should also avoid the workqueue. Everyone else should use workqueue by default to remain safe in the future (while auditing the code, every caller was preemptible except for the RCU case). Let bpf_link_put() use the worker unconditionally. Add bpf_link_put_direct() which will directly free the resources and is used by close() and from within __sys_bpf(). Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230614083430.oENawF8f@linutronix.de |
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Eduard Zingerman
|
1ffc85d929 |
bpf: Verify scalar ids mapping in regsafe() using check_ids()
Make sure that the following unsafe example is rejected by verifier:
1: r9 = ... some pointer with range X ...
2: r6 = ... unbound scalar ID=a ...
3: r7 = ... unbound scalar ID=b ...
4: if (r6 > r7) goto +1
5: r6 = r7
6: if (r6 > X) goto ...
--- checkpoint ---
7: r9 += r7
8: *(u64 *)r9 = Y
This example is unsafe because not all execution paths verify r7 range.
Because of the jump at (4) the verifier would arrive at (6) in two states:
I. r6{.id=b}, r7{.id=b} via path 1-6;
II. r6{.id=a}, r7{.id=b} via path 1-4, 6.
Currently regsafe() does not call check_ids() for scalar registers,
thus from POV of regsafe() states (I) and (II) are identical. If the
path 1-6 is taken by verifier first, and checkpoint is created at (6)
the path [1-4, 6] would be considered safe.
Changes in this commit:
- check_ids() is modified to disallow mapping multiple old_id to the
same cur_id.
- check_scalar_ids() is added, unlike check_ids() it treats ID zero as
a unique scalar ID.
- check_scalar_ids() needs to generate temporary unique IDs, field
'tmp_id_gen' is added to bpf_verifier_env::idmap_scratch to
facilitate this.
- regsafe() is updated to:
- use check_scalar_ids() for precise scalar registers.
- compare scalar registers using memcmp only for explore_alu_limits
branch. This simplifies control flow for scalar case, and has no
measurable performance impact.
- check_alu_op() is updated to avoid generating bpf_reg_state::id for
constant scalar values when processing BPF_MOV. ID is needed to
propagate range information for identical values, but there is
nothing to propagate for constants.
Fixes:
|
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Eduard Zingerman
|
904e6ddf41 |
bpf: Use scalar ids in mark_chain_precision()
Change mark_chain_precision() to track precision in situations
like below:
r2 = unknown value
...
--- state #0 ---
...
r1 = r2 // r1 and r2 now share the same ID
...
--- state #1 {r1.id = A, r2.id = A} ---
...
if (r2 > 10) goto exit; // find_equal_scalars() assigns range to r1
...
--- state #2 {r1.id = A, r2.id = A} ---
r3 = r10
r3 += r1 // need to mark both r1 and r2
At the beginning of the processing of each state, ensure that if a
register with a scalar ID is marked as precise, all registers sharing
this ID are also marked as precise.
This property would be used by a follow-up change in regsafe().
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230613153824.3324830-2-eddyz87@gmail.com
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Krister Johansen
|
0108a4e9f3 |
bpf: ensure main program has an extable
When subprograms are in use, the main program is not jit'd after the
subprograms because jit_subprogs sets a value for prog->bpf_func upon
success. Subsequent calls to the JIT are bypassed when this value is
non-NULL. This leads to a situation where the main program and its
func[0] counterpart are both in the bpf kallsyms tree, but only func[0]
has an extable. Extables are only created during JIT. Now there are
two nearly identical program ksym entries in the tree, but only one has
an extable. Depending upon how the entries are placed, there's a chance
that a fault will call search_extable on the aux with the NULL entry.
Since jit_subprogs already copies state from func[0] to the main
program, include the extable pointer in this state duplication.
Additionally, ensure that the copy of the main program in func[0] is not
added to the bpf_prog_kallsyms table. Instead, let the main program get
added later in bpf_prog_load(). This ensures there is only a single
copy of the main program in the kallsyms table, and that its tag matches
the tag observed by tooling like bpftool.
Cc: stable@vger.kernel.org
Fixes:
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David Vernet
|
f983be9173 |
bpf: Replace bpf_cpumask_any* with bpf_cpumask_any_distribute*
We currently export the bpf_cpumask_any() and bpf_cpumask_any_and() kfuncs. Intuitively, one would expect these to choose any CPU in the cpumask, but what they actually do is alias to cpumask_first() and cpmkas_first_and(). This is useless given that we already export bpf_cpumask_first() and bpf_cpumask_first_and(), so this patch replaces them with kfuncs that call cpumask_any_distribute() and cpumask_any_and_distribute(), which actually choose any CPU from the cpumask (or the AND of two cpumasks for the latter). Signed-off-by: David Vernet <void@manifault.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20230610035053.117605-3-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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David Vernet
|
5ba3a7a851 |
bpf: Add bpf_cpumask_first_and() kfunc
We currently provide bpf_cpumask_first(), bpf_cpumask_any(), and bpf_cpumask_any_and() kfuncs. bpf_cpumask_any() and bpf_cpumask_any_and() are confusing misnomers in that they actually just call cpumask_first() and cpumask_first_and() respectively. We'll replace them with bpf_cpumask_any_distribute() and bpf_cpumask_any_distribute_and() kfuncs in a subsequent patch, so let's ensure feature parity by adding a bpf_cpumask_first_and() kfunc to account for bpf_cpumask_any_and() being removed. Signed-off-by: David Vernet <void@manifault.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20230610035053.117605-1-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Arnd Bergmann
|
ba49f97688 |
bpf: Hide unused bpf_patch_call_args
This function is only used when CONFIG_BPF_JIT_ALWAYS_ON is disabled, but CONFIG_BPF_SYSCALL is enabled. When both are turned off, the prototype is missing but the unused function is still compiled, as seen from this W=1 warning: [...] kernel/bpf/core.c:2075:6: error: no previous prototype for 'bpf_patch_call_args' [-Werror=missing-prototypes] [...] Add a matching #ifdef for the definition to leave it out. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20230602135128.1498362-1-arnd@kernel.org |
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Jakub Kicinski
|
449f6bc17a |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR. Conflicts: net/sched/sch_taprio.c |
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Maxim Mikityanskiy
|
713274f1f2 |
bpf: Fix verifier id tracking of scalars on spill
The following scenario describes a bug in the verifier where it
incorrectly concludes about equivalent scalar IDs which could lead to
verifier bypass in privileged mode:
1. Prepare a 32-bit rogue number.
2. Put the rogue number into the upper half of a 64-bit register, and
roll a random (unknown to the verifier) bit in the lower half. The
rest of the bits should be zero (although variations are possible).
3. Assign an ID to the register by MOVing it to another arbitrary
register.
4. Perform a 32-bit spill of the register, then perform a 32-bit fill to
another register. Due to a bug in the verifier, the ID will be
preserved, although the new register will contain only the lower 32
bits, i.e. all zeros except one random bit.
At this point there are two registers with different values but the same
ID, which means the integrity of the verifier state has been corrupted.
5. Compare the new 32-bit register with 0. In the branch where it's
equal to 0, the verifier will believe that the original 64-bit
register is also 0, because it has the same ID, but its actual value
still contains the rogue number in the upper half.
Some optimizations of the verifier prevent the actual bypass, so
extra care is needed: the comparison must be between two registers,
and both branches must be reachable (this is why one random bit is
needed). Both branches are still suitable for the bypass.
6. Right shift the original register by 32 bits to pop the rogue number.
7. Use the rogue number as an offset with any pointer. The verifier will
believe that the offset is 0, while in reality it's the given number.
The fix is similar to the 32-bit BPF_MOV handling in check_alu_op for
SCALAR_VALUE. If the spill is narrowing the actual register value, don't
keep the ID, make sure it's reset to 0.
Fixes:
|
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Hou Tao
|
aa7881fcfe |
bpf: Factor out a common helper free_all()
Factor out a common helper free_all() to free all normal elements or per-cpu elements on a lock-less list. Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20230606035310.4026145-2-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Florian Westphal
|
132328e8e8 |
bpf: netfilter: Add BPF_NETFILTER bpf_attach_type
Andrii Nakryiko writes:
And we currently don't have an attach type for NETLINK BPF link.
Thankfully it's not too late to add it. I see that link_create() in
kernel/bpf/syscall.c just bypasses attach_type check. We shouldn't
have done that. Instead we need to add BPF_NETLINK attach type to enum
bpf_attach_type. And wire all that properly throughout the kernel and
libbpf itself.
This adds BPF_NETFILTER and uses it. This breaks uabi but this
wasn't in any non-rc release yet, so it should be fine.
v2: check link_attack prog type in link_create too
Fixes:
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David Vernet
|
51302c951c |
bpf: Teach verifier that trusted PTR_TO_BTF_ID pointers are non-NULL
In reg_type_not_null(), we currently assume that a pointer may be NULL
if it has the PTR_MAYBE_NULL modifier, or if it doesn't belong to one of
several base type of pointers that are never NULL-able. For example,
PTR_TO_CTX, PTR_TO_MAP_VALUE, etc.
It turns out that in some cases, PTR_TO_BTF_ID can never be NULL as
well, though we currently don't specify it. For example, if you had the
following program:
SEC("tc")
long example_refcnt_fail(void *ctx)
{
struct bpf_cpumask *mask1, *mask2;
mask1 = bpf_cpumask_create();
mask2 = bpf_cpumask_create();
if (!mask1 || !mask2)
goto error_release;
bpf_cpumask_test_cpu(0, (const struct cpumask *)mask1);
bpf_cpumask_test_cpu(0, (const struct cpumask *)mask2);
error_release:
if (mask1)
bpf_cpumask_release(mask1);
if (mask2)
bpf_cpumask_release(mask2);
return ret;
}
The verifier will incorrectly fail to load the program, thinking
(unintuitively) that we have a possibly-unreleased reference if the mask
is NULL, because we (correctly) don't issue a bpf_cpumask_release() on
the NULL path.
The reason the verifier gets confused is due to the fact that we don't
explicitly tell the verifier that trusted PTR_TO_BTF_ID pointers can
never be NULL. Basically, if we successfully get past the if check
(meaning both pointers go from ptr_or_null_bpf_cpumask to
ptr_bpf_cpumask), the verifier will correctly assume that the references
need to be dropped on any possible branch that leads to program exit.
However, it will _incorrectly_ think that the ptr == NULL branch is
possible, and will erroneously detect it as a branch on which we failed
to drop the reference.
The solution is of course to teach the verifier that trusted
PTR_TO_BTF_ID pointers can never be NULL, so that it doesn't incorrectly
think it's possible for the reference to be present on the ptr == NULL
branch.
A follow-on patch will add a selftest that verifies this behavior.
Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230602150112.1494194-1-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Daniel T. Lee
|
503e4def54 |
bpf: Replace open code with for allocated object check
>From commit |
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Dave Marchevsky
|
7793fc3bab |
bpf: Make bpf_refcount_acquire fallible for non-owning refs
This patch fixes an incorrect assumption made in the original
bpf_refcount series [0], specifically that the BPF program calling
bpf_refcount_acquire on some node can always guarantee that the node is
alive. In that series, the patch adding failure behavior to rbtree_add
and list_push_{front, back} breaks this assumption for non-owning
references.
Consider the following program:
n = bpf_kptr_xchg(&mapval, NULL);
/* skip error checking */
bpf_spin_lock(&l);
if(bpf_rbtree_add(&t, &n->rb, less)) {
bpf_refcount_acquire(n);
/* Failed to add, do something else with the node */
}
bpf_spin_unlock(&l);
It's incorrect to assume that bpf_refcount_acquire will always succeed in this
scenario. bpf_refcount_acquire is being called in a critical section
here, but the lock being held is associated with rbtree t, which isn't
necessarily the lock associated with the tree that the node is already
in. So after bpf_rbtree_add fails to add the node and calls bpf_obj_drop
in it, the program has no ownership of the node's lifetime. Therefore
the node's refcount can be decr'd to 0 at any time after the failing
rbtree_add. If this happens before the refcount_acquire above, the node
might be free'd, and regardless refcount_acquire will be incrementing a
0 refcount.
Later patches in the series exercise this scenario, resulting in the
expected complaint from the kernel (without this patch's changes):
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 207 at lib/refcount.c:25 refcount_warn_saturate+0xbc/0x110
Modules linked in: bpf_testmod(O)
CPU: 1 PID: 207 Comm: test_progs Tainted: G O 6.3.0-rc7-02231-g723de1a718a2-dirty #371
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
RIP: 0010:refcount_warn_saturate+0xbc/0x110
Code: 6f 64 f6 02 01 e8 84 a3 5c ff 0f 0b eb 9d 80 3d 5e 64 f6 02 00 75 94 48 c7 c7 e0 13 d2 82 c6 05 4e 64 f6 02 01 e8 64 a3 5c ff <0f> 0b e9 7a ff ff ff 80 3d 38 64 f6 02 00 0f 85 6d ff ff ff 48 c7
RSP: 0018:ffff88810b9179b0 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000000000
RDX: 0000000000000202 RSI: 0000000000000008 RDI: ffffffff857c3680
RBP: ffff88810027d3c0 R08: ffffffff8125f2a4 R09: ffff88810b9176e7
R10: ffffed1021722edc R11: 746e756f63666572 R12: ffff88810027d388
R13: ffff88810027d3c0 R14: ffffc900005fe030 R15: ffffc900005fe048
FS: 00007fee0584a700(0000) GS:ffff88811b280000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005634a96f6c58 CR3: 0000000108ce9002 CR4: 0000000000770ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<TASK>
bpf_refcount_acquire_impl+0xb5/0xc0
(rest of output snipped)
The patch addresses this by changing bpf_refcount_acquire_impl to use
refcount_inc_not_zero instead of refcount_inc and marking
bpf_refcount_acquire KF_RET_NULL.
For owning references, though, we know the above scenario is not possible
and thus that bpf_refcount_acquire will always succeed. Some verifier
bookkeeping is added to track "is input owning ref?" for bpf_refcount_acquire
calls and return false from is_kfunc_ret_null for bpf_refcount_acquire on
owning refs despite it being marked KF_RET_NULL.
Existing selftests using bpf_refcount_acquire are modified where
necessary to NULL-check its return value.
[0]: https://lore.kernel.org/bpf/20230415201811.343116-1-davemarchevsky@fb.com/
Fixes:
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Dave Marchevsky
|
cc0d76cafe |
bpf: Fix __bpf_{list,rbtree}_add's beginning-of-node calculation
Given the pointer to struct bpf_{rb,list}_node within a local kptr and
the byte offset of that field within the kptr struct, the calculation changed
by this patch is meant to find the beginning of the kptr so that it can
be passed to bpf_obj_drop.
Unfortunately instead of doing
ptr_to_kptr = ptr_to_node_field - offset_bytes
the calculation is erroneously doing
ptr_to_ktpr = ptr_to_node_field - (offset_bytes * sizeof(struct bpf_rb_node))
or the bpf_list_node equivalent.
This patch fixes the calculation.
Fixes:
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Dave Marchevsky
|
2140a6e342 |
bpf: Set kptr_struct_meta for node param to list and rbtree insert funcs
In verifier.c, fixup_kfunc_call uses struct bpf_insn_aux_data's
kptr_struct_meta field to pass information about local kptr types to
various helpers and kfuncs at runtime. The recent bpf_refcount series
added a few functions to the set that need this information:
* bpf_refcount_acquire
* Needs to know where the refcount field is in order to increment
* Graph collection insert kfuncs: bpf_rbtree_add, bpf_list_push_{front,back}
* Were migrated to possibly fail by the bpf_refcount series. If
insert fails, the input node is bpf_obj_drop'd. bpf_obj_drop needs
the kptr_struct_meta in order to decr refcount and properly free
special fields.
Unfortunately the verifier handling of collection insert kfuncs was not
modified to actually populate kptr_struct_meta. Accordingly, when the
node input to those kfuncs is passed to bpf_obj_drop, it is done so
without the information necessary to decr refcount.
This patch fixes the issue by populating kptr_struct_meta for those
kfuncs.
Fixes:
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Rhys Rustad-Elliott
|
cba41bb78d |
bpf: Fix elem_size not being set for inner maps
Commit |
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Azeem Shaikh
|
ffadc37252 |
bpf: Replace all non-returning strlcpy with strscpy
strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. This is not the case here, however, in an effort to remove strlcpy() completely [2], lets replace strlcpy() here with strscpy(). No return values were used, so a direct replacement is safe. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/bpf/20230530155659.309657-1-azeemshaikh38@gmail.com |
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Yonghong Song
|
e6c2f594ed |
bpf: Silence a warning in btf_type_id_size()
syzbot reported a warning in [1] with the following stacktrace:
WARNING: CPU: 0 PID: 5005 at kernel/bpf/btf.c:1988 btf_type_id_size+0x2d9/0x9d0 kernel/bpf/btf.c:1988
...
RIP: 0010:btf_type_id_size+0x2d9/0x9d0 kernel/bpf/btf.c:1988
...
Call Trace:
<TASK>
map_check_btf kernel/bpf/syscall.c:1024 [inline]
map_create+0x1157/0x1860 kernel/bpf/syscall.c:1198
__sys_bpf+0x127f/0x5420 kernel/bpf/syscall.c:5040
__do_sys_bpf kernel/bpf/syscall.c:5162 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5160 [inline]
__x64_sys_bpf+0x79/0xc0 kernel/bpf/syscall.c:5160
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
With the following btf
[1] DECL_TAG 'a' type_id=4 component_idx=-1
[2] PTR '(anon)' type_id=0
[3] TYPE_TAG 'a' type_id=2
[4] VAR 'a' type_id=3, linkage=static
and when the bpf_attr.btf_key_type_id = 1 (DECL_TAG),
the following WARN_ON_ONCE in btf_type_id_size() is triggered:
if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) &&
!btf_type_is_var(size_type)))
return NULL;
Note that 'return NULL' is the correct behavior as we don't want
a DECL_TAG type to be used as a btf_{key,value}_type_id even
for the case like 'DECL_TAG -> STRUCT'. So there
is no correctness issue here, we just want to silence warning.
To silence the warning, I added DECL_TAG as one of kinds in
btf_type_nosize() which will cause btf_type_id_size() returning
NULL earlier without the warning.
[1] https://lore.kernel.org/bpf/000000000000e0df8d05fc75ba86@google.com/
Reported-by: syzbot+958967f249155967d42a@syzkaller.appspotmail.com
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20230530205029.264910-1-yhs@fb.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
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Jakub Kicinski
|
75455b906d |
bpf-next-for-netdev
-----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTFp0I1jqZrAX+hPRXbK58LschIgwUCZHEm+wAKCRDbK58LschI gyIKAQCqO7B4sIu8hYVxBTwfHV2tIuXSMSCV4P9e78NUOPcO2QEAvLP/WVSjB0Bm vpyTKKM22SpZvPe/jSp52j6t20N+qAc= =HFxD -----END PGP SIGNATURE----- Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== pull-request: bpf-next 2023-05-26 We've added 54 non-merge commits during the last 10 day(s) which contain a total of 76 files changed, 2729 insertions(+), 1003 deletions(-). The main changes are: 1) Add the capability to destroy sockets in BPF through a new kfunc, from Aditi Ghag. 2) Support O_PATH fds in BPF_OBJ_PIN and BPF_OBJ_GET commands, from Andrii Nakryiko. 3) Add capability for libbpf to resize datasec maps when backed via mmap, from JP Kobryn. 4) Move all the test kfuncs for CI out of the kernel and into bpf_testmod, from Jiri Olsa. 5) Big batch of xsk selftest improvements to prep for multi-buffer testing, from Magnus Karlsson. 6) Show the target_{obj,btf}_id in tracing link's fdinfo and dump it via bpftool, from Yafang Shao. 7) Various misc BPF selftest improvements to work with upcoming LLVM 17, from Yonghong Song. 8) Extend bpftool to specify netdevice for resolving XDP hints, from Larysa Zaremba. 9) Document masking in shift operations for the insn set document, from Dave Thaler. 10) Extend BPF selftests to check xdp_feature support for bond driver, from Lorenzo Bianconi. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (54 commits) bpf: Fix bad unlock balance on freeze_mutex libbpf: Ensure FD >= 3 during bpf_map__reuse_fd() libbpf: Ensure libbpf always opens files with O_CLOEXEC selftests/bpf: Check whether to run selftest libbpf: Change var type in datasec resize func bpf: drop unnecessary bpf_capable() check in BPF_MAP_FREEZE command libbpf: Selftests for resizing datasec maps libbpf: Add capability for resizing datasec maps selftests/bpf: Add path_fd-based BPF_OBJ_PIN and BPF_OBJ_GET tests libbpf: Add opts-based bpf_obj_pin() API and add support for path_fd bpf: Support O_PATH FDs in BPF_OBJ_PIN and BPF_OBJ_GET commands libbpf: Start v1.3 development cycle bpf: Validate BPF object in BPF_OBJ_PIN before calling LSM bpftool: Specify XDP Hints ifname when loading program selftests/bpf: Add xdp_feature selftest for bond device selftests/bpf: Test bpf_sock_destroy selftests/bpf: Add helper to get port using getsockname bpf: Add bpf_sock_destroy kfunc bpf: Add kfunc filter function to 'struct btf_kfunc_id_set' bpf: udp: Implement batching for sockets iterator ... ==================== Link: https://lore.kernel.org/r/20230526222747.17775-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
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|
Daniel Borkmann
|
4266f41fea |
bpf: Fix bad unlock balance on freeze_mutex
Commit |
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Jakub Kicinski
|
d4031ec844 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR. Conflicts: net/ipv4/raw.c |
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Andrii Nakryiko
|
c4c84f6fb2 |
bpf: drop unnecessary bpf_capable() check in BPF_MAP_FREEZE command
Seems like that extra bpf_capable() check in BPF_MAP_FREEZE handler was unintentionally left when we switched to a model that all BPF map operations should be allowed regardless of CAP_BPF (or any other capabilities), as long as process got BPF map FD somehow. This patch replaces bpf_capable() check in BPF_MAP_FREEZE handler with writeable access check, given conceptually freezing the map is modifying it: map becomes unmodifiable for subsequent updates. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230524225421.1587859-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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|
Andrii Nakryiko
|
cb8edce280 |
bpf: Support O_PATH FDs in BPF_OBJ_PIN and BPF_OBJ_GET commands
Current UAPI of BPF_OBJ_PIN and BPF_OBJ_GET commands of bpf() syscall forces users to specify pinning location as a string-based absolute or relative (to current working directory) path. This has various implications related to security (e.g., symlink-based attacks), forces BPF FS to be exposed in the file system, which can cause races with other applications. One of the feedbacks we got from folks working with containers heavily was that inability to use purely FD-based location specification was an unfortunate limitation and hindrance for BPF_OBJ_PIN and BPF_OBJ_GET commands. This patch closes this oversight, adding path_fd field to BPF_OBJ_PIN and BPF_OBJ_GET UAPI, following conventions established by *at() syscalls for dirfd + pathname combinations. This now allows interesting possibilities like working with detached BPF FS mount (e.g., to perform multiple pinnings without running a risk of someone interfering with them), and generally making pinning/getting more secure and not prone to any races and/or security attacks. This is demonstrated by a selftest added in subsequent patch that takes advantage of new mount APIs (fsopen, fsconfig, fsmount) to demonstrate creating detached BPF FS mount, pinning, and then getting BPF map out of it, all while never exposing this private instance of BPF FS to outside worlds. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Christian Brauner <brauner@kernel.org> Link: https://lore.kernel.org/bpf/20230523170013.728457-4-andrii@kernel.org |
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Andrii Nakryiko
|
e7d85427ef |
bpf: Validate BPF object in BPF_OBJ_PIN before calling LSM
Do a sanity check whether provided file-to-be-pinned is actually a BPF object (prog, map, btf) before calling security_path_mknod LSM hook. If it's not, LSM hook doesn't have to be triggered, as the operation has no chance of succeeding anyways. Suggested-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Christian Brauner <brauner@kernel.org> Link: https://lore.kernel.org/bpf/20230522232917.2454595-2-andrii@kernel.org |
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Anton Protopopov
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b34ffb0c6d |
bpf: fix a memory leak in the LRU and LRU_PERCPU hash maps
The LRU and LRU_PERCPU maps allocate a new element on update before locking the
target hash table bucket. Right after that the maps try to lock the bucket.
If this fails, then maps return -EBUSY to the caller without releasing the
allocated element. This makes the element untracked: it doesn't belong to
either of free lists, and it doesn't belong to the hash table, so can't be
re-used; this eventually leads to the permanent -ENOMEM on LRU map updates,
which is unexpected. Fix this by returning the element to the local free list
if bucket locking fails.
Fixes:
|
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Aditi Ghag
|
e924e80ee6 |
bpf: Add kfunc filter function to 'struct btf_kfunc_id_set'
This commit adds the ability to filter kfuncs to certain BPF program types. This is required to limit bpf_sock_destroy kfunc implemented in follow-up commits to programs with attach type 'BPF_TRACE_ITER'. The commit adds a callback filter to 'struct btf_kfunc_id_set'. The filter has access to the `bpf_prog` construct including its properties such as `expected_attached_type`. Signed-off-by: Aditi Ghag <aditi.ghag@isovalent.com> Link: https://lore.kernel.org/r/20230519225157.760788-7-aditi.ghag@isovalent.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> |
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Yafang Shao
|
e859e42951 |
bpf: Show target_{obj,btf}_id in tracing link fdinfo
The target_btf_id can help us understand which kernel function is linked by a tracing prog. The target_btf_id and target_obj_id have already been exposed to userspace, so we just need to show them. The result as follows, $ cat /proc/10673/fdinfo/10 pos: 0 flags: 02000000 mnt_id: 15 ino: 2094 link_type: tracing link_id: 2 prog_tag: a04f5eef06a7f555 prog_id: 13 attach_type: 24 target_obj_id: 1 target_btf_id: 13964 Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Acked-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230517103126.68372-2-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Will Deacon
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0613d8ca9a |
bpf: Fix mask generation for 32-bit narrow loads of 64-bit fields
A narrow load from a 64-bit context field results in a 64-bit load
followed potentially by a 64-bit right-shift and then a bitwise AND
operation to extract the relevant data.
In the case of a 32-bit access, an immediate mask of 0xffffffff is used
to construct a 64-bit BPP_AND operation which then sign-extends the mask
value and effectively acts as a glorified no-op. For example:
0: 61 10 00 00 00 00 00 00 r0 = *(u32 *)(r1 + 0)
results in the following code generation for a 64-bit field:
ldr x7, [x7] // 64-bit load
mov x10, #0xffffffffffffffff
and x7, x7, x10
Fix the mask generation so that narrow loads always perform a 32-bit AND
operation:
ldr x7, [x7] // 64-bit load
mov w10, #0xffffffff
and w7, w7, w10
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Krzesimir Nowak <krzesimir@kinvolk.io>
Cc: Andrey Ignatov <rdna@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Fixes:
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Andrii Nakryiko
|
cff36398bd |
bpf: drop unnecessary user-triggerable WARN_ONCE in verifierl log
It's trivial for user to trigger "verifier log line truncated" warning, as verifier has a fixed-sized buffer of 1024 bytes (as of now), and there are at least two pieces of user-provided information that can be output through this buffer, and both can be arbitrarily sized by user: - BTF names; - BTF.ext source code lines strings. Verifier log buffer should be properly sized for typical verifier state output. But it's sort-of expected that this buffer won't be long enough in some circumstances. So let's drop the check. In any case code will work correctly, at worst truncating a part of a single line output. Reported-by: syzbot+8b2a08dfbd25fd933d75@syzkaller.appspotmail.com Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230516180409.3549088-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Jakub Kicinski
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a0e35a648f |
bpf-next-for-netdev
-----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTFp0I1jqZrAX+hPRXbK58LschIgwUCZGKqEAAKCRDbK58LschI g6LYAQDp1jAszCOkmJ8VUA0ZyC5NAFDv+7y9Nd1toYWYX1btzAEAkf8+5qBJ1qmI P5M0hjMTbH4MID9Aql10ZbMHheyOBAo= =NUQM -----END PGP SIGNATURE----- Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== pull-request: bpf-next 2023-05-16 We've added 57 non-merge commits during the last 19 day(s) which contain a total of 63 files changed, 3293 insertions(+), 690 deletions(-). The main changes are: 1) Add precision propagation to verifier for subprogs and callbacks, from Andrii Nakryiko. 2) Improve BPF's {g,s}setsockopt() handling with wrong option lengths, from Stanislav Fomichev. 3) Utilize pahole v1.25 for the kernel's BTF generation to filter out inconsistent function prototypes, from Alan Maguire. 4) Various dyn-pointer verifier improvements to relax restrictions, from Daniel Rosenberg. 5) Add a new bpf_task_under_cgroup() kfunc for designated task, from Feng Zhou. 6) Unblock tests for arm64 BPF CI after ftrace supporting direct call, from Florent Revest. 7) Add XDP hint kfunc metadata for RX hash/timestamp for igc, from Jesper Dangaard Brouer. 8) Add several new dyn-pointer kfuncs to ease their usability, from Joanne Koong. 9) Add in-depth LRU internals description and dot function graph, from Joe Stringer. 10) Fix KCSAN report on bpf_lru_list when accessing node->ref, from Martin KaFai Lau. 11) Only dump unprivileged_bpf_disabled log warning upon write, from Kui-Feng Lee. 12) Extend test_progs to directly passing allow/denylist file, from Stephen Veiss. 13) Fix BPF trampoline memleak upon failure attaching to fentry, from Yafang Shao. 14) Fix emitting struct bpf_tcp_sock type in vmlinux BTF, from Yonghong Song. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (57 commits) bpf: Fix memleak due to fentry attach failure bpf: Remove bpf trampoline selector bpf, arm64: Support struct arguments in the BPF trampoline bpftool: JIT limited misreported as negative value on aarch64 bpf: fix calculation of subseq_idx during precision backtracking bpf: Remove anonymous union in bpf_kfunc_call_arg_meta bpf: Document EFAULT changes for sockopt selftests/bpf: Correctly handle optlen > 4096 selftests/bpf: Update EFAULT {g,s}etsockopt selftests bpf: Don't EFAULT for {g,s}setsockopt with wrong optlen libbpf: fix offsetof() and container_of() to work with CO-RE bpf: Address KCSAN report on bpf_lru_list bpf: Add --skip_encoding_btf_inconsistent_proto, --btf_gen_optimized to pahole flags for v1.25 selftests/bpf: Accept mem from dynptr in helper funcs bpf: verifier: Accept dynptr mem as mem in helpers selftests/bpf: Check overflow in optional buffer selftests/bpf: Test allowing NULL buffer in dynptr slice bpf: Allow NULL buffers in bpf_dynptr_slice(_rw) selftests/bpf: Add testcase for bpf_task_under_cgroup bpf: Add bpf_task_under_cgroup() kfunc ... ==================== Link: https://lore.kernel.org/r/20230515225603.27027-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
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Yafang Shao
|
108598c39e |
bpf: Fix memleak due to fentry attach failure
If it fails to attach fentry, the allocated bpf trampoline image will be
left in the system. That can be verified by checking /proc/kallsyms.
This meamleak can be verified by a simple bpf program as follows:
SEC("fentry/trap_init")
int fentry_run()
{
return 0;
}
It will fail to attach trap_init because this function is freed after
kernel init, and then we can find the trampoline image is left in the
system by checking /proc/kallsyms.
$ tail /proc/kallsyms
ffffffffc0613000 t bpf_trampoline_6442453466_1 [bpf]
ffffffffc06c3000 t bpf_trampoline_6442453466_1 [bpf]
$ bpftool btf dump file /sys/kernel/btf/vmlinux | grep "FUNC 'trap_init'"
[2522] FUNC 'trap_init' type_id=119 linkage=static
$ echo $((6442453466 & 0x7fffffff))
2522
Note that there are two left bpf trampoline images, that is because the
libbpf will fallback to raw tracepoint if -EINVAL is returned.
Fixes:
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Yafang Shao
|
47e79cbeea |
bpf: Remove bpf trampoline selector
After commit |
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Andrii Nakryiko
|
d84b1a6708 |
bpf: fix calculation of subseq_idx during precision backtracking
Subsequent instruction index (subseq_idx) is an index of an instruction
that was verified/executed by verifier after the currently processed
instruction. It is maintained during precision backtracking processing
and is used to detect various subprog calling conditions.
This patch fixes the bug with incorrectly resetting subseq_idx to -1
when going from child state to parent state during backtracking. If we
don't maintain correct subseq_idx we can misidentify subprog calls
leading to precision tracking bugs.
One such case was triggered by test_global_funcs/global_func9 test where
global subprog call happened to be the very last instruction in parent
state, leading to subseq_idx==-1, triggering WARN_ONCE:
[ 36.045754] verifier backtracking bug
[ 36.045764] WARNING: CPU: 13 PID: 2073 at kernel/bpf/verifier.c:3503 __mark_chain_precision+0xcc6/0xde0
[ 36.046819] Modules linked in: aesni_intel(E) crypto_simd(E) cryptd(E) kvm_intel(E) kvm(E) irqbypass(E) i2c_piix4(E) serio_raw(E) i2c_core(E) crc32c_intel)
[ 36.048040] CPU: 13 PID: 2073 Comm: test_progs Tainted: G W OE 6.3.0-07976-g4d585f48ee6b-dirty #972
[ 36.048783] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
[ 36.049648] RIP: 0010:__mark_chain_precision+0xcc6/0xde0
[ 36.050038] Code: 3d 82 c6 05 bb 35 32 02 01 e8 66 21 ec ff 0f 0b b8 f2 ff ff ff e9 30 f5 ff ff 48 c7 c7 f3 61 3d 82 4c 89 0c 24 e8 4a 21 ec ff <0f> 0b 4c0
With the fix precision tracking across multiple states works correctly now:
mark_precise: frame0: last_idx 45 first_idx 38 subseq_idx -1
mark_precise: frame0: regs=r8 stack= before 44: (61) r7 = *(u32 *)(r10 -4)
mark_precise: frame0: regs=r8 stack= before 43: (85) call pc+41
mark_precise: frame0: regs=r8 stack= before 42: (07) r1 += -48
mark_precise: frame0: regs=r8 stack= before 41: (bf) r1 = r10
mark_precise: frame0: regs=r8 stack= before 40: (63) *(u32 *)(r10 -48) = r1
mark_precise: frame0: regs=r8 stack= before 39: (b4) w1 = 0
mark_precise: frame0: regs=r8 stack= before 38: (85) call pc+38
mark_precise: frame0: parent state regs=r8 stack=: R0_w=scalar() R1_w=map_value(off=4,ks=4,vs=8,imm=0) R6=1 R7_w=scalar() R8_r=P0 R10=fpm
mark_precise: frame0: last_idx 36 first_idx 28 subseq_idx 38
mark_precise: frame0: regs=r8 stack= before 36: (18) r1 = 0xffff888104f2ed14
mark_precise: frame0: regs=r8 stack= before 35: (85) call pc+33
mark_precise: frame0: regs=r8 stack= before 33: (18) r1 = 0xffff888104f2ed10
mark_precise: frame0: regs=r8 stack= before 32: (85) call pc+36
mark_precise: frame0: regs=r8 stack= before 31: (07) r1 += -4
mark_precise: frame0: regs=r8 stack= before 30: (bf) r1 = r10
mark_precise: frame0: regs=r8 stack= before 29: (63) *(u32 *)(r10 -4) = r7
mark_precise: frame0: regs=r8 stack= before 28: (4c) w7 |= w0
mark_precise: frame0: parent state regs=r8 stack=: R0_rw=scalar() R6=1 R7_rw=scalar() R8_rw=P0 R10=fp0 fp-48_r=mmmmmmmm
mark_precise: frame0: last_idx 27 first_idx 16 subseq_idx 28
mark_precise: frame0: regs=r8 stack= before 27: (85) call pc+31
mark_precise: frame0: regs=r8 stack= before 26: (b7) r1 = 0
mark_precise: frame0: regs=r8 stack= before 25: (b7) r8 = 0
Note how subseq_idx starts out as -1, then is preserved as 38 and then 28 as we
go up the parent state chain.
Reported-by: Alexei Starovoitov <ast@kernel.org>
Fixes:
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||
|
Dave Marchevsky
|
4d585f48ee |
bpf: Remove anonymous union in bpf_kfunc_call_arg_meta
For kfuncs like bpf_obj_drop and bpf_refcount_acquire - which take
user-defined types as input - the verifier needs to track the specific
type passed in when checking a particular kfunc call. This requires
tracking (btf, btf_id) tuple. In commit
|
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|
Jakub Kicinski
|
e1505c1cc8 |
bpf: netdev: init the offload table earlier
Some netdevices may get unregistered before late_initcall(),
we have to move the hashtable init earlier.
Fixes:
|
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|
Stanislav Fomichev
|
29ebbba7d4 |
bpf: Don't EFAULT for {g,s}setsockopt with wrong optlen
With the way the hooks implemented right now, we have a special
condition: optval larger than PAGE_SIZE will expose only first 4k into
BPF; any modifications to the optval are ignored. If the BPF program
doesn't handle this condition by resetting optlen to 0,
the userspace will get EFAULT.
The intention of the EFAULT was to make it apparent to the
developers that the program is doing something wrong.
However, this inadvertently might affect production workloads
with the BPF programs that are not too careful (i.e., returning EFAULT
for perfectly valid setsockopt/getsockopt calls).
Let's try to minimize the chance of BPF program screwing up userspace
by ignoring the output of those BPF programs (instead of returning
EFAULT to the userspace). pr_info_once those cases to
the dmesg to help with figuring out what's going wrong.
Fixes:
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Martin KaFai Lau
|
ee9fd0ac30 |
bpf: Address KCSAN report on bpf_lru_list
KCSAN reported a data-race when accessing node->ref. Although node->ref does not have to be accurate, take this chance to use a more common READ_ONCE() and WRITE_ONCE() pattern instead of data_race(). There is an existing bpf_lru_node_is_ref() and bpf_lru_node_set_ref(). This patch also adds bpf_lru_node_clear_ref() to do the WRITE_ONCE(node->ref, 0) also. ================================================================== BUG: KCSAN: data-race in __bpf_lru_list_rotate / __htab_lru_percpu_map_update_elem write to 0xffff888137038deb of 1 bytes by task 11240 on cpu 1: __bpf_lru_node_move kernel/bpf/bpf_lru_list.c:113 [inline] __bpf_lru_list_rotate_active kernel/bpf/bpf_lru_list.c:149 [inline] __bpf_lru_list_rotate+0x1bf/0x750 kernel/bpf/bpf_lru_list.c:240 bpf_lru_list_pop_free_to_local kernel/bpf/bpf_lru_list.c:329 [inline] bpf_common_lru_pop_free kernel/bpf/bpf_lru_list.c:447 [inline] bpf_lru_pop_free+0x638/0xe20 kernel/bpf/bpf_lru_list.c:499 prealloc_lru_pop kernel/bpf/hashtab.c:290 [inline] __htab_lru_percpu_map_update_elem+0xe7/0x820 kernel/bpf/hashtab.c:1316 bpf_percpu_hash_update+0x5e/0x90 kernel/bpf/hashtab.c:2313 bpf_map_update_value+0x2a9/0x370 kernel/bpf/syscall.c:200 generic_map_update_batch+0x3ae/0x4f0 kernel/bpf/syscall.c:1687 bpf_map_do_batch+0x2d9/0x3d0 kernel/bpf/syscall.c:4534 __sys_bpf+0x338/0x810 __do_sys_bpf kernel/bpf/syscall.c:5096 [inline] __se_sys_bpf kernel/bpf/syscall.c:5094 [inline] __x64_sys_bpf+0x43/0x50 kernel/bpf/syscall.c:5094 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffff888137038deb of 1 bytes by task 11241 on cpu 0: bpf_lru_node_set_ref kernel/bpf/bpf_lru_list.h:70 [inline] __htab_lru_percpu_map_update_elem+0x2f1/0x820 kernel/bpf/hashtab.c:1332 bpf_percpu_hash_update+0x5e/0x90 kernel/bpf/hashtab.c:2313 bpf_map_update_value+0x2a9/0x370 kernel/bpf/syscall.c:200 generic_map_update_batch+0x3ae/0x4f0 kernel/bpf/syscall.c:1687 bpf_map_do_batch+0x2d9/0x3d0 kernel/bpf/syscall.c:4534 __sys_bpf+0x338/0x810 __do_sys_bpf kernel/bpf/syscall.c:5096 [inline] __se_sys_bpf kernel/bpf/syscall.c:5094 [inline] __x64_sys_bpf+0x43/0x50 kernel/bpf/syscall.c:5094 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x01 -> 0x00 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 11241 Comm: syz-executor.3 Not tainted 6.3.0-rc7-syzkaller-00136-g6a66fdd29ea1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 ================================================================== Reported-by: syzbot+ebe648a84e8784763f82@syzkaller.appspotmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20230511043748.1384166-1-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Daniel Rosenberg
|
2012c867c8 |
bpf: verifier: Accept dynptr mem as mem in helpers
This allows using memory retrieved from dynptrs with helper functions that accept ARG_PTR_TO_MEM. For instance, results from bpf_dynptr_data can be passed along to bpf_strncmp. Signed-off-by: Daniel Rosenberg <drosen@google.com> Link: https://lore.kernel.org/r/20230506013134.2492210-5-drosen@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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|
Daniel Rosenberg
|
3bda08b636 |
bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)
bpf_dynptr_slice(_rw) uses a user provided buffer if it can not provide a pointer to a block of contiguous memory. This buffer is unused in the case of local dynptrs, and may be unused in other cases as well. There is no need to require the buffer, as the kfunc can just return NULL if it was needed and not provided. This adds another kfunc annotation, __opt, which combines with __sz and __szk to allow the buffer associated with the size to be NULL. If the buffer is NULL, the verifier does not check that the buffer is of sufficient size. Signed-off-by: Daniel Rosenberg <drosen@google.com> Link: https://lore.kernel.org/r/20230506013134.2492210-2-drosen@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Feng Zhou
|
b5ad4cdc46 |
bpf: Add bpf_task_under_cgroup() kfunc
Add a kfunc that's similar to the bpf_current_task_under_cgroup. The difference is that it is a designated task. When hook sched related functions, sometimes it is necessary to specify a task instead of the current task. Signed-off-by: Feng Zhou <zhoufeng.zf@bytedance.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/r/20230506031545.35991-2-zhoufeng.zf@bytedance.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
fde2a3882b |
bpf: support precision propagation in the presence of subprogs
Add support precision backtracking in the presence of subprogram frames in
jump history.
This means supporting a few different kinds of subprogram invocation
situations, all requiring a slightly different handling in precision
backtracking handling logic:
- static subprogram calls;
- global subprogram calls;
- callback-calling helpers/kfuncs.
For each of those we need to handle a few precision propagation cases:
- what to do with precision of subprog returns (r0);
- what to do with precision of input arguments;
- for all of them callee-saved registers in caller function should be
propagated ignoring subprog/callback part of jump history.
N.B. Async callback-calling helpers (currently only
bpf_timer_set_callback()) are transparent to all this because they set
a separate async callback environment and thus callback's history is not
shared with main program's history. So as far as all the changes in this
commit goes, such helper is just a regular helper.
Let's look at all these situation in more details. Let's start with
static subprogram being called, using an exxerpt of a simple main
program and its static subprog, indenting subprog's frame slightly to
make everything clear.
frame 0 frame 1 precision set
======= ======= =============
9: r6 = 456;
10: r1 = 123; fr0: r6
11: call pc+10; fr0: r1, r6
22: r0 = r1; fr0: r6; fr1: r1
23: exit fr0: r6; fr1: r0
12: r1 = <map_pointer> fr0: r0, r6
13: r1 += r0; fr0: r0, r6
14: r1 += r6; fr0: r6
15: exit
As can be seen above main function is passing 123 as single argument to
an identity (`return x;`) subprog. Returned value is used to adjust map
pointer offset, which forces r0 to be marked as precise. Then
instruction #14 does the same for callee-saved r6, which will have to be
backtracked all the way to instruction #9. For brevity, precision sets
for instruction #13 and #14 are combined in the diagram above.
First, for subprog calls, r0 returned from subprog (in frame 0) has to
go into subprog's frame 1, and should be cleared from frame 0. So we go
back into subprog's frame knowing we need to mark r0 precise. We then
see that insn #22 sets r0 from r1, so now we care about marking r1
precise. When we pop up from subprog's frame back into caller at
insn #11 we keep r1, as it's an argument-passing register, so we eventually
find `10: r1 = 123;` and satify precision propagation chain for insn #13.
This example demonstrates two sets of rules:
- r0 returned after subprog call has to be moved into subprog's r0 set;
- *static* subprog arguments (r1-r5) are moved back to caller precision set.
Let's look at what happens with callee-saved precision propagation. Insn #14
mark r6 as precise. When we get into subprog's frame, we keep r6 in
frame 0's precision set *only*. Subprog itself has its own set of
independent r6-r10 registers and is not affected. When we eventually
made our way out of subprog frame we keep r6 in precision set until we
reach `9: r6 = 456;`, satisfying propagation. r6-r10 propagation is
perhaps the simplest aspect, it always stays in its original frame.
That's pretty much all we have to do to support precision propagation
across *static subprog* invocation.
Let's look at what happens when we have global subprog invocation.
frame 0 frame 1 precision set
======= ======= =============
9: r6 = 456;
10: r1 = 123; fr0: r6
11: call pc+10; # global subprog fr0: r6
12: r1 = <map_pointer> fr0: r0, r6
13: r1 += r0; fr0: r0, r6
14: r1 += r6; fr0: r6;
15: exit
Starting from insn #13, r0 has to be precise. We backtrack all the way
to insn #11 (call pc+10) and see that subprog is global, so was already
validated in isolation. As opposed to static subprog, global subprog
always returns unknown scalar r0, so that satisfies precision
propagation and we drop r0 from precision set. We are done for insns #13.
Now for insn #14. r6 is in precision set, we backtrack to `call pc+10;`.
Here we need to recognize that this is effectively both exit and entry
to global subprog, which means we stay in caller's frame. So we carry on
with r6 still in precision set, until we satisfy it at insn #9. The only
hard part with global subprogs is just knowing when it's a global func.
Lastly, callback-calling helpers and kfuncs do simulate subprog calls,
so jump history will have subprog instructions in between caller
program's instructions, but the rules of propagating r0 and r1-r5
differ, because we don't actually directly call callback. We actually
call helper/kfunc, which at runtime will call subprog, so the only
difference between normal helper/kfunc handling is that we need to make
sure to skip callback simulatinog part of jump history.
Let's look at an example to make this clearer.
frame 0 frame 1 precision set
======= ======= =============
8: r6 = 456;
9: r1 = 123; fr0: r6
10: r2 = &callback; fr0: r6
11: call bpf_loop; fr0: r6
22: r0 = r1; fr0: r6 fr1:
23: exit fr0: r6 fr1:
12: r1 = <map_pointer> fr0: r0, r6
13: r1 += r0; fr0: r0, r6
14: r1 += r6; fr0: r6;
15: exit
Again, insn #13 forces r0 to be precise. As soon as we get to `23: exit`
we see that this isn't actually a static subprog call (it's `call
bpf_loop;` helper call instead). So we clear r0 from precision set.
For callee-saved register, there is no difference: it stays in frame 0's
precision set, we go through insn #22 and #23, ignoring them until we
get back to caller frame 0, eventually satisfying precision backtrack
logic at insn #8 (`r6 = 456;`).
Assuming callback needed to set r0 as precise at insn #23, we'd
backtrack to insn #22, switching from r0 to r1, and then at the point
when we pop back to frame 0 at insn #11, we'll clear r1-r5 from
precision set, as we don't really do a subprog call directly, so there
is no input argument precision propagation.
That's pretty much it. With these changes, it seems like the only still
unsupported situation for precision backpropagation is the case when
program is accessing stack through registers other than r10. This is
still left as unsupported (though rare) case for now.
As for results. For selftests, few positive changes for bigger programs,
cls_redirect in dynptr variant benefitting the most:
[vmuser@archvm bpf]$ ./veristat -C ~/subprog-precise-before-results.csv ~/subprog-precise-after-results.csv -f @veristat.cfg -e file,prog,insns -f 'insns_diff!=0'
File Program Insns (A) Insns (B) Insns (DIFF)
---------------------------------------- ------------- --------- --------- ----------------
pyperf600_bpf_loop.bpf.linked1.o on_event 2060 2002 -58 (-2.82%)
test_cls_redirect_dynptr.bpf.linked1.o cls_redirect 15660 2914 -12746 (-81.39%)
test_cls_redirect_subprogs.bpf.linked1.o cls_redirect 61620 59088 -2532 (-4.11%)
xdp_synproxy_kern.bpf.linked1.o syncookie_tc 109980 86278 -23702 (-21.55%)
xdp_synproxy_kern.bpf.linked1.o syncookie_xdp 97716 85147 -12569 (-12.86%)
Cilium progress don't really regress. They don't use subprogs and are
mostly unaffected, but some other fixes and improvements could have
changed something. This doesn't appear to be the case:
[vmuser@archvm bpf]$ ./veristat -C ~/subprog-precise-before-results-cilium.csv ~/subprog-precise-after-results-cilium.csv -e file,prog,insns -f 'insns_diff!=0'
File Program Insns (A) Insns (B) Insns (DIFF)
------------- ------------------------------ --------- --------- ------------
bpf_host.o tail_nodeport_nat_ingress_ipv6 4983 5003 +20 (+0.40%)
bpf_lxc.o tail_nodeport_nat_ingress_ipv6 4983 5003 +20 (+0.40%)
bpf_overlay.o tail_nodeport_nat_ingress_ipv6 4983 5003 +20 (+0.40%)
bpf_xdp.o tail_handle_nat_fwd_ipv6 12475 12504 +29 (+0.23%)
bpf_xdp.o tail_nodeport_nat_ingress_ipv6 6363 6371 +8 (+0.13%)
Looking at (somewhat anonymized) Meta production programs, we see mostly
insignificant variation in number of instructions, with one program
(syar_bind6_protect6) benefitting the most at -17%.
[vmuser@archvm bpf]$ ./veristat -C ~/subprog-precise-before-results-fbcode.csv ~/subprog-precise-after-results-fbcode.csv -e prog,insns -f 'insns_diff!=0'
Program Insns (A) Insns (B) Insns (DIFF)
------------------------ --------- --------- ----------------
on_request_context_event 597 585 -12 (-2.01%)
read_async_py_stack 43789 43657 -132 (-0.30%)
read_sync_py_stack 35041 37599 +2558 (+7.30%)
rrm_usdt 946 940 -6 (-0.63%)
sysarmor_inet6_bind 28863 28249 -614 (-2.13%)
sysarmor_inet_bind 28845 28240 -605 (-2.10%)
syar_bind4_protect4 154145 147640 -6505 (-4.22%)
syar_bind6_protect6 165242 137088 -28154 (-17.04%)
syar_task_exit_setgid 21289 19720 -1569 (-7.37%)
syar_task_exit_setuid 21290 19721 -1569 (-7.37%)
do_uprobe 19967 19413 -554 (-2.77%)
tw_twfw_ingress 215877 204833 -11044 (-5.12%)
tw_twfw_tc_in 215877 204833 -11044 (-5.12%)
But checking duration (wall clock) differences, that is the actual time taken
by verifier to validate programs, we see a sometimes dramatic improvements, all
the way to about 16x improvements:
[vmuser@archvm bpf]$ ./veristat -C ~/subprog-precise-before-results-meta.csv ~/subprog-precise-after-results-meta.csv -e prog,duration -s duration_diff^ | head -n20
Program Duration (us) (A) Duration (us) (B) Duration (us) (DIFF)
---------------------------------------- ----------------- ----------------- --------------------
tw_twfw_ingress 4488374 272836 -4215538 (-93.92%)
tw_twfw_tc_in 4339111 268175 -4070936 (-93.82%)
tw_twfw_egress 3521816 270751 -3251065 (-92.31%)
tw_twfw_tc_eg 3472878 284294 -3188584 (-91.81%)
balancer_ingress 343119 291391 -51728 (-15.08%)
syar_bind6_protect6 78992 64782 -14210 (-17.99%)
ttls_tc_ingress 11739 8176 -3563 (-30.35%)
kprobe__security_inode_link 13864 11341 -2523 (-18.20%)
read_sync_py_stack 21927 19442 -2485 (-11.33%)
read_async_py_stack 30444 28136 -2308 (-7.58%)
syar_task_exit_setuid 10256 8440 -1816 (-17.71%)
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230505043317.3629845-9-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Andrii Nakryiko
|
c50c0b57a5 |
bpf: fix mark_all_scalars_precise use in mark_chain_precision
When precision backtracking bails out due to some unsupported sequence of instructions (e.g., stack access through register other than r10), we need to mark all SCALAR registers as precise to be safe. Currently, though, we mark SCALARs precise only starting from the state we detected unsupported condition, which could be one of the parent states of the actual current state. This will leave some registers potentially not marked as precise, even though they should. So make sure we start marking scalars as precise from current state (env->cur_state). Further, we don't currently detect a situation when we end up with some stack slots marked as needing precision, but we ran out of available states to find the instructions that populate those stack slots. This is akin the `i >= func->allocated_stack / BPF_REG_SIZE` check and should be handled similarly by falling back to marking all SCALARs precise. Add this check when we run out of states. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230505043317.3629845-8-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
f655badf2a |
bpf: fix propagate_precision() logic for inner frames
Fix propagate_precision() logic to perform propagation of all necessary
registers and stack slots across all active frames *in one batch step*.
Doing this for each register/slot in each individual frame is wasteful,
but the main problem is that backtracking of instruction in any frame
except the deepest one just doesn't work. This is due to backtracking
logic relying on jump history, and available jump history always starts
(or ends, depending how you view it) in current frame. So, if
prog A (frame #0) called subprog B (frame #1) and we need to propagate
precision of, say, register R6 (callee-saved) within frame #0, we
actually don't even know where jump history that corresponds to prog
A even starts. We'd need to skip subprog part of jump history first to
be able to do this.
Luckily, with struct backtrack_state and __mark_chain_precision()
handling bitmasks tracking/propagation across all active frames at the
same time (added in previous patch), propagate_precision() can be both
fixed and sped up by setting all the necessary bits across all frames
and then performing one __mark_chain_precision() pass. This makes it
unnecessary to skip subprog parts of jump history.
We also improve logging along the way, to clearly specify which
registers' and slots' precision markings are propagated within which
frame. Each frame will have dedicated line and all registers and stack
slots from that frame will be reported in format similar to precision
backtrack regs/stack logging. E.g.:
frame 1: propagating r1,r2,r3,fp-8,fp-16
frame 0: propagating r3,r9,fp-120
Fixes:
|
||
|
Andrii Nakryiko
|
1ef22b6865 |
bpf: maintain bitmasks across all active frames in __mark_chain_precision
Teach __mark_chain_precision logic to maintain register/stack masks across all active frames when going from child state to parent state. Currently this should be mostly no-op, as precision backtracking usually bails out when encountering subprog entry/exit. It's not very apparent from the diff due to increased indentation, but the logic remains the same, except everything is done on specific `fr` frame index. Calls to bt_clear_reg() and bt_clear_slot() are replaced with frame-specific bt_clear_frame_reg() and bt_clear_frame_slot(), where frame index is passed explicitly, instead of using current frame number. We also adjust logging to emit affected frame number. And we also add better logging of human-readable register and stack slot masks, similar to previous patch. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230505043317.3629845-6-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
d9439c21a9 |
bpf: improve precision backtrack logging
Add helper to format register and stack masks in more human-readable format. Adjust logging a bit during backtrack propagation and especially during forcing precision fallback logic to make it clearer what's going on (with log_level=2, of course), and also start reporting affected frame depth. This is in preparation for having more than one active frame later when precision propagation between subprog calls is added. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230505043317.3629845-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
407958a0e9 |
bpf: encapsulate precision backtracking bookkeeping
Add struct backtrack_state and straightforward API around it to keep track of register and stack masks used and maintained during precision backtracking process. Having this logic separately allow to keep high-level backtracking algorithm cleaner, but also it sets us up to cleanly keep track of register and stack masks per frame, allowing (with some further logic adjustments) to perform precision backpropagation across multiple frames (i.e., subprog calls). Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230505043317.3629845-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
e0bf462276 |
bpf: mark relevant stack slots scratched for register read instructions
When handling instructions that read register slots, mark relevant stack slots as scratched so that verifier log would contain those slots' states, in addition to currently emitted registers with stack slot offsets. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230505043317.3629845-3-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Kui-Feng Lee
|
fedf99200a |
bpf: Print a warning only if writing to unprivileged_bpf_disabled.
Only print the warning message if you are writing to "/proc/sys/kernel/unprivileged_bpf_disabled". The kernel may print an annoying warning when you read "/proc/sys/kernel/unprivileged_bpf_disabled" saying WARNING: Unprivileged eBPF is enabled with eIBRS on, data leaks possible via Spectre v2 BHB attacks! However, this message is only meaningful when the feature is disabled or enabled. Signed-off-by: Kui-Feng Lee <kuifeng@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20230502181418.308479-1-kuifeng@meta.com |
||
|
Linus Torvalds
|
86e98ed15b |
cgroup changes for v6.4-rc1
* cpuset changes including the fix for an incorrect interaction with CPU hotplug and an optimization. * Other doc and cosmetic changes. -----BEGIN PGP SIGNATURE----- iIQEABYIACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCZErfng4cdGpAa2VybmVs Lm9yZwAKCRCxYfJx3gVYGVVtAQCDycK4VSgc4nsFPG1vh1Oy1A723ciEUwAbKmV/ F1n7xwEA68FiDvE29LpMJJuYP9HnX0A5zRMyNnb52kN9jmgcEQI= =ALol -----END PGP SIGNATURE----- Merge tag 'cgroup-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - cpuset changes including the fix for an incorrect interaction with CPU hotplug and an optimization - Other doc and cosmetic changes * tag 'cgroup-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: docs: cgroup-v1/cpusets: update libcgroup project link cgroup/cpuset: Minor updates to test_cpuset_prs.sh cgroup/cpuset: Include offline CPUs when tasks' cpumasks in top_cpuset are updated cgroup/cpuset: Skip task update if hotplug doesn't affect current cpuset cpuset: Clean up cpuset_node_allowed cgroup: bpf: use cgroup_lock()/cgroup_unlock() wrappers |
||
|
Joanne Koong
|
361f129f3c |
bpf: Add bpf_dynptr_clone
The cloned dynptr will point to the same data as its parent dynptr, with the same type, offset, size and read-only properties. Any writes to a dynptr will be reflected across all instances (by 'instance', this means any dynptrs that point to the same underlying data). Please note that data slice and dynptr invalidations will affect all instances as well. For example, if bpf_dynptr_write() is called on an skb-type dynptr, all data slices of dynptr instances to that skb will be invalidated as well (eg data slices of any clones, parents, grandparents, ...). Another example is if a ringbuf dynptr is submitted, any instance of that dynptr will be invalidated. Changing the view of the dynptr (eg advancing the offset or trimming the size) will only affect that dynptr and not affect any other instances. One example use case where cloning may be helpful is for hashing or iterating through dynptr data. Cloning will allow the user to maintain the original view of the dynptr for future use, while also allowing views to smaller subsets of the data after the offset is advanced or the size is trimmed. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230420071414.570108-5-joannelkoong@gmail.com |
||
|
Joanne Koong
|
26662d7347 |
bpf: Add bpf_dynptr_size
bpf_dynptr_size returns the number of usable bytes in a dynptr. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20230420071414.570108-4-joannelkoong@gmail.com |
||
|
Joanne Koong
|
540ccf96dd |
bpf: Add bpf_dynptr_is_null and bpf_dynptr_is_rdonly
bpf_dynptr_is_null returns true if the dynptr is null / invalid (determined by whether ptr->data is NULL), else false if the dynptr is a valid dynptr. bpf_dynptr_is_rdonly returns true if the dynptr is read-only, else false if the dynptr is read-writable. If the dynptr is null / invalid, false is returned by default. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20230420071414.570108-3-joannelkoong@gmail.com |
||
|
Joanne Koong
|
987d0242d1 |
bpf: Add bpf_dynptr_adjust
Add a new kfunc int bpf_dynptr_adjust(struct bpf_dynptr_kern *ptr, u32 start, u32 end); which adjusts the dynptr to reflect the new [start, end) interval. In particular, it advances the offset of the dynptr by "start" bytes, and if end is less than the size of the dynptr, then this will trim the dynptr accordingly. Adjusting the dynptr interval may be useful in certain situations. For example, when hashing which takes in generic dynptrs, if the dynptr points to a struct but only a certain memory region inside the struct should be hashed, adjust can be used to narrow in on the specific region to hash. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230420071414.570108-2-joannelkoong@gmail.com |
||
|
Linus Torvalds
|
6e98b09da9 |
Networking changes for 6.4.
Core
----
- Introduce a config option to tweak MAX_SKB_FRAGS. Increasing the
default value allows for better BIG TCP performances.
- Reduce compound page head access for zero-copy data transfers.
- RPS/RFS improvements, avoiding unneeded NET_RX_SOFTIRQ when possible.
- Threaded NAPI improvements, adding defer skb free support and unneeded
softirq avoidance.
- Address dst_entry reference count scalability issues, via false
sharing avoidance and optimize refcount tracking.
- Add lockless accesses annotation to sk_err[_soft].
- Optimize again the skb struct layout.
- Extends the skb drop reasons to make it usable by multiple
subsystems.
- Better const qualifier awareness for socket casts.
BPF
---
- Add skb and XDP typed dynptrs which allow BPF programs for more
ergonomic and less brittle iteration through data and variable-sized
accesses.
- Add a new BPF netfilter program type and minimal support to hook
BPF programs to netfilter hooks such as prerouting or forward.
- Add more precise memory usage reporting for all BPF map types.
- Adds support for using {FOU,GUE} encap with an ipip device operating
in collect_md mode and add a set of BPF kfuncs for controlling encap
params.
- Allow BPF programs to detect at load time whether a particular kfunc
exists or not, and also add support for this in light skeleton.
- Bigger batch of BPF verifier improvements to prepare for upcoming BPF
open-coded iterators allowing for less restrictive looping capabilities.
- Rework RCU enforcement in the verifier, add kptr_rcu and enforce BPF
programs to NULL-check before passing such pointers into kfunc.
- Add support for kptrs in percpu hashmaps, percpu LRU hashmaps and in
local storage maps.
- Enable RCU semantics for task BPF kptrs and allow referenced kptr
tasks to be stored in BPF maps.
- Add support for refcounted local kptrs to the verifier for allowing
shared ownership, useful for adding a node to both the BPF list and
rbtree.
- Add BPF verifier support for ST instructions in convert_ctx_access()
which will help new -mcpu=v4 clang flag to start emitting them.
- Add ARM32 USDT support to libbpf.
- Improve bpftool's visual program dump which produces the control
flow graph in a DOT format by adding C source inline annotations.
Protocols
---------
- IPv4: Allow adding to IPv4 address a 'protocol' tag. Such value
indicates the provenance of the IP address.
- IPv6: optimize route lookup, dropping unneeded R/W lock acquisition.
- Add the handshake upcall mechanism, allowing the user-space
to implement generic TLS handshake on kernel's behalf.
- Bridge: support per-{Port, VLAN} neighbor suppression, increasing
resilience to nodes failures.
- SCTP: add support for Fair Capacity and Weighted Fair Queueing
schedulers.
- MPTCP: delay first subflow allocation up to its first usage. This
will allow for later better LSM interaction.
- xfrm: Remove inner/outer modes from input/output path. These are
not needed anymore.
- WiFi:
- reduced neighbor report (RNR) handling for AP mode
- HW timestamping support
- support for randomized auth/deauth TA for PASN privacy
- per-link debugfs for multi-link
- TC offload support for mac80211 drivers
- mac80211 mesh fast-xmit and fast-rx support
- enable Wi-Fi 7 (EHT) mesh support
Netfilter
---------
- Add nf_tables 'brouting' support, to force a packet to be routed
instead of being bridged.
- Update bridge netfilter and ovs conntrack helpers to handle
IPv6 Jumbo packets properly, i.e. fetch the packet length
from hop-by-hop extension header. This is needed for BIT TCP
support.
- The iptables 32bit compat interface isn't compiled in by default
anymore.
- Move ip(6)tables builtin icmp matches to the udptcp one.
This has the advantage that icmp/icmpv6 match doesn't load the
iptables/ip6tables modules anymore when iptables-nft is used.
- Extended netlink error report for netdevice in flowtables and
netdev/chains. Allow for incrementally add/delete devices to netdev
basechain. Allow to create netdev chain without device.
Driver API
----------
- Remove redundant Device Control Error Reporting Enable, as PCI core
has already error reporting enabled at enumeration time.
- Move Multicast DB netlink handlers to core, allowing devices other
then bridge to use them.
- Allow the page_pool to directly recycle the pages from safely
localized NAPI.
- Implement lockless TX queue stop/wake combo macros, allowing for
further code de-duplication and sanitization.
- Add YNL support for user headers and struct attrs.
- Add partial YNL specification for devlink.
- Add partial YNL specification for ethtool.
- Add tc-mqprio and tc-taprio support for preemptible traffic classes.
- Add tx push buf len param to ethtool, specifies the maximum number
of bytes of a transmitted packet a driver can push directly to the
underlying device.
- Add basic LED support for switch/phy.
- Add NAPI documentation, stop relaying on external links.
- Convert dsa_master_ioctl() to netdev notifier. This is a preparatory
work to make the hardware timestamping layer selectable by user
space.
- Add transceiver support and improve the error messages for CAN-FD
controllers.
New hardware / drivers
----------------------
- Ethernet:
- AMD/Pensando core device support
- MediaTek MT7981 SoC
- MediaTek MT7988 SoC
- Broadcom BCM53134 embedded switch
- Texas Instruments CPSW9G ethernet switch
- Qualcomm EMAC3 DWMAC ethernet
- StarFive JH7110 SoC
- NXP CBTX ethernet PHY
- WiFi:
- Apple M1 Pro/Max devices
- RealTek rtl8710bu/rtl8188gu
- RealTek rtl8822bs, rtl8822cs and rtl8821cs SDIO chipset
- Bluetooth:
- Realtek RTL8821CS, RTL8851B, RTL8852BS
- Mediatek MT7663, MT7922
- NXP w8997
- Actions Semi ATS2851
- QTI WCN6855
- Marvell 88W8997
- Can:
- STMicroelectronics bxcan stm32f429
Drivers
-------
- Ethernet NICs:
- Intel (1G, icg):
- add tracking and reporting of QBV config errors.
- add support for configuring max SDU for each Tx queue.
- Intel (100G, ice):
- refactor mailbox overflow detection to support Scalable IOV
- GNSS interface optimization
- Intel (i40e):
- support XDP multi-buffer
- nVidia/Mellanox:
- add the support for linux bridge multicast offload
- enable TC offload for egress and engress MACVLAN over bond
- add support for VxLAN GBP encap/decap flows offload
- extend packet offload to fully support libreswan
- support tunnel mode in mlx5 IPsec packet offload
- extend XDP multi-buffer support
- support MACsec VLAN offload
- add support for dynamic msix vectors allocation
- drop RX page_cache and fully use page_pool
- implement thermal zone to report NIC temperature
- Netronome/Corigine:
- add support for multi-zone conntrack offload
- Solarflare/Xilinx:
- support offloading TC VLAN push/pop actions to the MAE
- support TC decap rules
- support unicast PTP
- Other NICs:
- Broadcom (bnxt): enforce software based freq adjustments only
on shared PHC NIC
- RealTek (r8169): refactor to addess ASPM issues during NAPI poll.
- Micrel (lan8841): add support for PTP_PF_PEROUT
- Cadence (macb): enable PTP unicast
- Engleder (tsnep): add XDP socket zero-copy support
- virtio-net: implement exact header length guest feature
- veth: add page_pool support for page recycling
- vxlan: add MDB data path support
- gve: add XDP support for GQI-QPL format
- geneve: accept every ethertype
- macvlan: allow some packets to bypass broadcast queue
- mana: add support for jumbo frame
- Ethernet high-speed switches:
- Microchip (sparx5): Add support for TC flower templates.
- Ethernet embedded switches:
- Broadcom (b54):
- configure 6318 and 63268 RGMII ports
- Marvell (mv88e6xxx):
- faster C45 bus scan
- Microchip:
- lan966x:
- add support for IS1 VCAP
- better TX/RX from/to CPU performances
- ksz9477: add ETS Qdisc support
- ksz8: enhance static MAC table operations and error handling
- sama7g5: add PTP capability
- NXP (ocelot):
- add support for external ports
- add support for preemptible traffic classes
- Texas Instruments:
- add CPSWxG SGMII support for J7200 and J721E
- Intel WiFi (iwlwifi):
- preparation for Wi-Fi 7 EHT and multi-link support
- EHT (Wi-Fi 7) sniffer support
- hardware timestamping support for some devices/firwmares
- TX beacon protection on newer hardware
- Qualcomm 802.11ax WiFi (ath11k):
- MU-MIMO parameters support
- ack signal support for management packets
- RealTek WiFi (rtw88):
- SDIO bus support
- better support for some SDIO devices
(e.g. MAC address from efuse)
- RealTek WiFi (rtw89):
- HW scan support for 8852b
- better support for 6 GHz scanning
- support for various newer firmware APIs
- framework firmware backwards compatibility
- MediaTek WiFi (mt76):
- P2P support
- mesh A-MSDU support
- EHT (Wi-Fi 7) support
- coredump support
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-next-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Paolo Abeni:
"Core:
- Introduce a config option to tweak MAX_SKB_FRAGS. Increasing the
default value allows for better BIG TCP performances
- Reduce compound page head access for zero-copy data transfers
- RPS/RFS improvements, avoiding unneeded NET_RX_SOFTIRQ when
possible
- Threaded NAPI improvements, adding defer skb free support and
unneeded softirq avoidance
- Address dst_entry reference count scalability issues, via false
sharing avoidance and optimize refcount tracking
- Add lockless accesses annotation to sk_err[_soft]
- Optimize again the skb struct layout
- Extends the skb drop reasons to make it usable by multiple
subsystems
- Better const qualifier awareness for socket casts
BPF:
- Add skb and XDP typed dynptrs which allow BPF programs for more
ergonomic and less brittle iteration through data and
variable-sized accesses
- Add a new BPF netfilter program type and minimal support to hook
BPF programs to netfilter hooks such as prerouting or forward
- Add more precise memory usage reporting for all BPF map types
- Adds support for using {FOU,GUE} encap with an ipip device
operating in collect_md mode and add a set of BPF kfuncs for
controlling encap params
- Allow BPF programs to detect at load time whether a particular
kfunc exists or not, and also add support for this in light
skeleton
- Bigger batch of BPF verifier improvements to prepare for upcoming
BPF open-coded iterators allowing for less restrictive looping
capabilities
- Rework RCU enforcement in the verifier, add kptr_rcu and enforce
BPF programs to NULL-check before passing such pointers into kfunc
- Add support for kptrs in percpu hashmaps, percpu LRU hashmaps and
in local storage maps
- Enable RCU semantics for task BPF kptrs and allow referenced kptr
tasks to be stored in BPF maps
- Add support for refcounted local kptrs to the verifier for allowing
shared ownership, useful for adding a node to both the BPF list and
rbtree
- Add BPF verifier support for ST instructions in
convert_ctx_access() which will help new -mcpu=v4 clang flag to
start emitting them
- Add ARM32 USDT support to libbpf
- Improve bpftool's visual program dump which produces the control
flow graph in a DOT format by adding C source inline annotations
Protocols:
- IPv4: Allow adding to IPv4 address a 'protocol' tag. Such value
indicates the provenance of the IP address
- IPv6: optimize route lookup, dropping unneeded R/W lock acquisition
- Add the handshake upcall mechanism, allowing the user-space to
implement generic TLS handshake on kernel's behalf
- Bridge: support per-{Port, VLAN} neighbor suppression, increasing
resilience to nodes failures
- SCTP: add support for Fair Capacity and Weighted Fair Queueing
schedulers
- MPTCP: delay first subflow allocation up to its first usage. This
will allow for later better LSM interaction
- xfrm: Remove inner/outer modes from input/output path. These are
not needed anymore
- WiFi:
- reduced neighbor report (RNR) handling for AP mode
- HW timestamping support
- support for randomized auth/deauth TA for PASN privacy
- per-link debugfs for multi-link
- TC offload support for mac80211 drivers
- mac80211 mesh fast-xmit and fast-rx support
- enable Wi-Fi 7 (EHT) mesh support
Netfilter:
- Add nf_tables 'brouting' support, to force a packet to be routed
instead of being bridged
- Update bridge netfilter and ovs conntrack helpers to handle IPv6
Jumbo packets properly, i.e. fetch the packet length from
hop-by-hop extension header. This is needed for BIT TCP support
- The iptables 32bit compat interface isn't compiled in by default
anymore
- Move ip(6)tables builtin icmp matches to the udptcp one. This has
the advantage that icmp/icmpv6 match doesn't load the
iptables/ip6tables modules anymore when iptables-nft is used
- Extended netlink error report for netdevice in flowtables and
netdev/chains. Allow for incrementally add/delete devices to netdev
basechain. Allow to create netdev chain without device
Driver API:
- Remove redundant Device Control Error Reporting Enable, as PCI core
has already error reporting enabled at enumeration time
- Move Multicast DB netlink handlers to core, allowing devices other
then bridge to use them
- Allow the page_pool to directly recycle the pages from safely
localized NAPI
- Implement lockless TX queue stop/wake combo macros, allowing for
further code de-duplication and sanitization
- Add YNL support for user headers and struct attrs
- Add partial YNL specification for devlink
- Add partial YNL specification for ethtool
- Add tc-mqprio and tc-taprio support for preemptible traffic classes
- Add tx push buf len param to ethtool, specifies the maximum number
of bytes of a transmitted packet a driver can push directly to the
underlying device
- Add basic LED support for switch/phy
- Add NAPI documentation, stop relaying on external links
- Convert dsa_master_ioctl() to netdev notifier. This is a
preparatory work to make the hardware timestamping layer selectable
by user space
- Add transceiver support and improve the error messages for CAN-FD
controllers
New hardware / drivers:
- Ethernet:
- AMD/Pensando core device support
- MediaTek MT7981 SoC
- MediaTek MT7988 SoC
- Broadcom BCM53134 embedded switch
- Texas Instruments CPSW9G ethernet switch
- Qualcomm EMAC3 DWMAC ethernet
- StarFive JH7110 SoC
- NXP CBTX ethernet PHY
- WiFi:
- Apple M1 Pro/Max devices
- RealTek rtl8710bu/rtl8188gu
- RealTek rtl8822bs, rtl8822cs and rtl8821cs SDIO chipset
- Bluetooth:
- Realtek RTL8821CS, RTL8851B, RTL8852BS
- Mediatek MT7663, MT7922
- NXP w8997
- Actions Semi ATS2851
- QTI WCN6855
- Marvell 88W8997
- Can:
- STMicroelectronics bxcan stm32f429
Drivers:
- Ethernet NICs:
- Intel (1G, icg):
- add tracking and reporting of QBV config errors
- add support for configuring max SDU for each Tx queue
- Intel (100G, ice):
- refactor mailbox overflow detection to support Scalable IOV
- GNSS interface optimization
- Intel (i40e):
- support XDP multi-buffer
- nVidia/Mellanox:
- add the support for linux bridge multicast offload
- enable TC offload for egress and engress MACVLAN over bond
- add support for VxLAN GBP encap/decap flows offload
- extend packet offload to fully support libreswan
- support tunnel mode in mlx5 IPsec packet offload
- extend XDP multi-buffer support
- support MACsec VLAN offload
- add support for dynamic msix vectors allocation
- drop RX page_cache and fully use page_pool
- implement thermal zone to report NIC temperature
- Netronome/Corigine:
- add support for multi-zone conntrack offload
- Solarflare/Xilinx:
- support offloading TC VLAN push/pop actions to the MAE
- support TC decap rules
- support unicast PTP
- Other NICs:
- Broadcom (bnxt): enforce software based freq adjustments only on
shared PHC NIC
- RealTek (r8169): refactor to addess ASPM issues during NAPI poll
- Micrel (lan8841): add support for PTP_PF_PEROUT
- Cadence (macb): enable PTP unicast
- Engleder (tsnep): add XDP socket zero-copy support
- virtio-net: implement exact header length guest feature
- veth: add page_pool support for page recycling
- vxlan: add MDB data path support
- gve: add XDP support for GQI-QPL format
- geneve: accept every ethertype
- macvlan: allow some packets to bypass broadcast queue
- mana: add support for jumbo frame
- Ethernet high-speed switches:
- Microchip (sparx5): Add support for TC flower templates
- Ethernet embedded switches:
- Broadcom (b54):
- configure 6318 and 63268 RGMII ports
- Marvell (mv88e6xxx):
- faster C45 bus scan
- Microchip:
- lan966x:
- add support for IS1 VCAP
- better TX/RX from/to CPU performances
- ksz9477: add ETS Qdisc support
- ksz8: enhance static MAC table operations and error handling
- sama7g5: add PTP capability
- NXP (ocelot):
- add support for external ports
- add support for preemptible traffic classes
- Texas Instruments:
- add CPSWxG SGMII support for J7200 and J721E
- Intel WiFi (iwlwifi):
- preparation for Wi-Fi 7 EHT and multi-link support
- EHT (Wi-Fi 7) sniffer support
- hardware timestamping support for some devices/firwmares
- TX beacon protection on newer hardware
- Qualcomm 802.11ax WiFi (ath11k):
- MU-MIMO parameters support
- ack signal support for management packets
- RealTek WiFi (rtw88):
- SDIO bus support
- better support for some SDIO devices (e.g. MAC address from
efuse)
- RealTek WiFi (rtw89):
- HW scan support for 8852b
- better support for 6 GHz scanning
- support for various newer firmware APIs
- framework firmware backwards compatibility
- MediaTek WiFi (mt76):
- P2P support
- mesh A-MSDU support
- EHT (Wi-Fi 7) support
- coredump support"
* tag 'net-next-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2078 commits)
net: phy: hide the PHYLIB_LEDS knob
net: phy: marvell-88x2222: remove unnecessary (void*) conversions
tcp/udp: Fix memleaks of sk and zerocopy skbs with TX timestamp.
net: amd: Fix link leak when verifying config failed
net: phy: marvell: Fix inconsistent indenting in led_blink_set
lan966x: Don't use xdp_frame when action is XDP_TX
tsnep: Add XDP socket zero-copy TX support
tsnep: Add XDP socket zero-copy RX support
tsnep: Move skb receive action to separate function
tsnep: Add functions for queue enable/disable
tsnep: Rework TX/RX queue initialization
tsnep: Replace modulo operation with mask
net: phy: dp83867: Add led_brightness_set support
net: phy: Fix reading LED reg property
drivers: nfc: nfcsim: remove return value check of `dev_dir`
net: phy: dp83867: Remove unnecessary (void*) conversions
net: ethtool: coalesce: try to make user settings stick twice
net: mana: Check if netdev/napi_alloc_frag returns single page
net: mana: Rename mana_refill_rxoob and remove some empty lines
net: veth: add page_pool stats
...
|
||
|
Linus Torvalds
|
df45da57cb |
arm64 updates for 6.4
ACPI: * Improve error reporting when failing to manage SDEI on AGDI device removal Assembly routines: * Improve register constraints so that the compiler can make use of the zero register instead of moving an immediate #0 into a GPR * Allow the compiler to allocate the registers used for CAS instructions CPU features and system registers: * Cleanups to the way in which CPU features are identified from the ID register fields * Extend system register definition generation to handle Enum types when defining shared register fields * Generate definitions for new _EL2 registers and add new fields for ID_AA64PFR1_EL1 * Allow SVE to be disabled separately from SME on the kernel command-line Tracing: * Support for "direct calls" in ftrace, which enables BPF tracing for arm64 Kdump: * Don't bother unmapping the crashkernel from the linear mapping, which then allows us to use huge (block) mappings and reduce TLB pressure when a crashkernel is loaded. Memory management: * Try again to remove data cache invalidation from the coherent DMA allocation path * Simplify the fixmap code by mapping at page granularity * Allow the kfence pool to be allocated early, preventing the rest of the linear mapping from being forced to page granularity Perf and PMU: * Move CPU PMU code out to drivers/perf/ where it can be reused by the 32-bit ARM architecture when running on ARMv8 CPUs * Fix race between CPU PMU probing and pKVM host de-privilege * Add support for Apple M2 CPU PMU * Adjust the generic PERF_COUNT_HW_BRANCH_INSTRUCTIONS event dynamically, depending on what the CPU actually supports * Minor fixes and cleanups to system PMU drivers Stack tracing: * Use the XPACLRI instruction to strip PAC from pointers, rather than rolling our own function in C * Remove redundant PAC removal for toolchains that handle this in their builtins * Make backtracing more resilient in the face of instrumentation Miscellaneous: * Fix single-step with KGDB * Remove harmless warning when 'nokaslr' is passed on the kernel command-line * Minor fixes and cleanups across the board -----BEGIN PGP SIGNATURE----- iQFEBAABCgAuFiEEPxTL6PPUbjXGY88ct6xw3ITBYzQFAmRChcwQHHdpbGxAa2Vy bmVsLm9yZwAKCRC3rHDchMFjNCgBCADFvkYY9ESztSnd3EpiMbbAzgRCQBiA5H7U F2Wc+hIWgeAeUEttSH22+F16r6Jb0gbaDvsuhtN2W/rwQhKNbCU0MaUME05MPmg2 AOp+RZb2vdT5i5S5dC6ZM6G3T6u9O78LBWv2JWBdd6RIybamEn+RL00ep2WAduH7 n1FgTbsKgnbScD2qd4K1ejZ1W/BQMwYulkNpyTsmCIijXM12lkzFlxWnMtky3uhR POpawcIZzXvWI02QAX+SIdynGChQV3VP+dh9GuFbt7ASigDEhgunvfUYhZNSaqf4 +/q0O8toCtmQJBUhF0DEDSB5T8SOz5v9CKxKuwfaX6Trq0ixFQpZ =78L9 -----END PGP SIGNATURE----- Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "ACPI: - Improve error reporting when failing to manage SDEI on AGDI device removal Assembly routines: - Improve register constraints so that the compiler can make use of the zero register instead of moving an immediate #0 into a GPR - Allow the compiler to allocate the registers used for CAS instructions CPU features and system registers: - Cleanups to the way in which CPU features are identified from the ID register fields - Extend system register definition generation to handle Enum types when defining shared register fields - Generate definitions for new _EL2 registers and add new fields for ID_AA64PFR1_EL1 - Allow SVE to be disabled separately from SME on the kernel command-line Tracing: - Support for "direct calls" in ftrace, which enables BPF tracing for arm64 Kdump: - Don't bother unmapping the crashkernel from the linear mapping, which then allows us to use huge (block) mappings and reduce TLB pressure when a crashkernel is loaded. Memory management: - Try again to remove data cache invalidation from the coherent DMA allocation path - Simplify the fixmap code by mapping at page granularity - Allow the kfence pool to be allocated early, preventing the rest of the linear mapping from being forced to page granularity Perf and PMU: - Move CPU PMU code out to drivers/perf/ where it can be reused by the 32-bit ARM architecture when running on ARMv8 CPUs - Fix race between CPU PMU probing and pKVM host de-privilege - Add support for Apple M2 CPU PMU - Adjust the generic PERF_COUNT_HW_BRANCH_INSTRUCTIONS event dynamically, depending on what the CPU actually supports - Minor fixes and cleanups to system PMU drivers Stack tracing: - Use the XPACLRI instruction to strip PAC from pointers, rather than rolling our own function in C - Remove redundant PAC removal for toolchains that handle this in their builtins - Make backtracing more resilient in the face of instrumentation Miscellaneous: - Fix single-step with KGDB - Remove harmless warning when 'nokaslr' is passed on the kernel command-line - Minor fixes and cleanups across the board" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (72 commits) KVM: arm64: Ensure CPU PMU probes before pKVM host de-privilege arm64: kexec: include reboot.h arm64: delete dead code in this_cpu_set_vectors() arm64/cpufeature: Use helper macro to specify ID register for capabilites drivers/perf: hisi: add NULL check for name drivers/perf: hisi: Remove redundant initialized of pmu->name arm64/cpufeature: Consistently use symbolic constants for min_field_value arm64/cpufeature: Pull out helper for CPUID register definitions arm64/sysreg: Convert HFGITR_EL2 to automatic generation ACPI: AGDI: Improve error reporting for problems during .remove() arm64: kernel: Fix kernel warning when nokaslr is passed to commandline perf/arm-cmn: Fix port detection for CMN-700 arm64: kgdb: Set PSTATE.SS to 1 to re-enable single-step arm64: move PAC masks to <asm/pointer_auth.h> arm64: use XPACLRI to strip PAC arm64: avoid redundant PAC stripping in __builtin_return_address() arm64/sme: Fix some comments of ARM SME arm64/signal: Alloc tpidr2 sigframe after checking system_supports_tpidr2() arm64/signal: Use system_supports_tpidr2() to check TPIDR2 arm64/idreg: Don't disable SME when disabling SVE ... |
||
|
Linus Torvalds
|
ef36b9afc2 |
fget() to fdget() conversions
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCZEYCQAAKCRBZ7Krx/gZQ 64FdAQDZ2hTDyZEWPt486dWYPYpiKyaGFXSXDGo7wgP0fiwxXQEA/mROKb6JqYw6 27mZ9A7qluT8r3AfTTQ0D+Yse/dr4AM= =GA9W -----END PGP SIGNATURE----- Merge tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs fget updates from Al Viro: "fget() to fdget() conversions" * tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fuse_dev_ioctl(): switch to fdget() cgroup_get_from_fd(): switch to fdget_raw() bpf: switch to fdget_raw() build_mount_idmapped(): switch to fdget() kill the last remaining user of proc_ns_fget() SVM-SEV: convert the rest of fget() uses to fdget() in there convert sgx_set_attribute() to fdget()/fdput() convert setns(2) to fdget()/fdput() |
||
|
Yafang Shao
|
a0c109dcaf |
bpf: Add __rcu_read_{lock,unlock} into btf id deny list
The tracing recursion prevention mechanism must be protected by rcu, that
leaves __rcu_read_{lock,unlock} unprotected by this mechanism. If we trace
them, the recursion will happen. Let's add them into the btf id deny list.
When CONFIG_PREEMPT_RCU is enabled, it can be reproduced with a simple bpf
program as such:
SEC("fentry/__rcu_read_lock")
int fentry_run()
{
return 0;
}
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230424161104.3737-2-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Dave Marchevsky
|
7deca5eae8 |
bpf: Disable bpf_refcount_acquire kfunc calls until race conditions are fixed
As reported by Kumar in [0], the shared ownership implementation for BPF programs has some race conditions which need to be addressed before it can safely be used. This patch does so in a minimal way instead of ripping out shared ownership entirely, as proper fixes for the issues raised will follow ASAP, at which point this patch's commit can be reverted to re-enable shared ownership. The patch removes the ability to call bpf_refcount_acquire_impl from BPF programs. Programs can only bump refcount and obtain a new owning reference using this kfunc, so removing the ability to call it effectively disables shared ownership. Instead of changing success / failure expectations for bpf_refcount-related selftests, this patch just disables them from running for now. [0]: https://lore.kernel.org/bpf/d7hyspcow5wtjcmw4fugdgyp3fwhljwuscp3xyut5qnwivyeru@ysdq543otzv2/ Reported-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/r/20230424204321.2680232-1-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Jakub Kicinski
|
9a82cdc28f |
bpf-next-for-netdev
-----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTFp0I1jqZrAX+hPRXbK58LschIgwUCZELn8wAKCRDbK58LschI g1khAQC1nmXPuKjM4EAfFK8Ysb3KoF8ADmpE97n+/HEDydCagwD/bX0+NABR75Nh ueGcoU1TcfcbshDzrH0s+C95owZDZw4= =BeZM -----END PGP SIGNATURE----- Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== pull-request: bpf-next 2023-04-21 We've added 71 non-merge commits during the last 8 day(s) which contain a total of 116 files changed, 13397 insertions(+), 8896 deletions(-). The main changes are: 1) Add a new BPF netfilter program type and minimal support to hook BPF programs to netfilter hooks such as prerouting or forward, from Florian Westphal. 2) Fix race between btf_put and btf_idr walk which caused a deadlock, from Alexei Starovoitov. 3) Second big batch to migrate test_verifier unit tests into test_progs for ease of readability and debugging, from Eduard Zingerman. 4) Add support for refcounted local kptrs to the verifier for allowing shared ownership, useful for adding a node to both the BPF list and rbtree, from Dave Marchevsky. 5) Migrate bpf_for(), bpf_for_each() and bpf_repeat() macros from BPF selftests into libbpf-provided bpf_helpers.h header and improve kfunc handling, from Andrii Nakryiko. 6) Support 64-bit pointers to kfuncs needed for archs like s390x, from Ilya Leoshkevich. 7) Support BPF progs under getsockopt with a NULL optval, from Stanislav Fomichev. 8) Improve verifier u32 scalar equality checking in order to enable LLVM transformations which earlier had to be disabled specifically for BPF backend, from Yonghong Song. 9) Extend bpftool's struct_ops object loading to support links, from Kui-Feng Lee. 10) Add xsk selftest follow-up fixes for hugepage allocated umem, from Magnus Karlsson. 11) Support BPF redirects from tc BPF to ifb devices, from Daniel Borkmann. 12) Add BPF support for integer type when accessing variable length arrays, from Feng Zhou. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (71 commits) selftests/bpf: verifier/value_ptr_arith converted to inline assembly selftests/bpf: verifier/value_illegal_alu converted to inline assembly selftests/bpf: verifier/unpriv converted to inline assembly selftests/bpf: verifier/subreg converted to inline assembly selftests/bpf: verifier/spin_lock converted to inline assembly selftests/bpf: verifier/sock converted to inline assembly selftests/bpf: verifier/search_pruning converted to inline assembly selftests/bpf: verifier/runtime_jit converted to inline assembly selftests/bpf: verifier/regalloc converted to inline assembly selftests/bpf: verifier/ref_tracking converted to inline assembly selftests/bpf: verifier/map_ptr_mixing converted to inline assembly selftests/bpf: verifier/map_in_map converted to inline assembly selftests/bpf: verifier/lwt converted to inline assembly selftests/bpf: verifier/loops1 converted to inline assembly selftests/bpf: verifier/jeq_infer_not_null converted to inline assembly selftests/bpf: verifier/direct_packet_access converted to inline assembly selftests/bpf: verifier/d_path converted to inline assembly selftests/bpf: verifier/ctx converted to inline assembly selftests/bpf: verifier/btf_ctx_access converted to inline assembly selftests/bpf: verifier/bpf_get_stack converted to inline assembly ... ==================== Link: https://lore.kernel.org/r/20230421211035.9111-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
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Florian Westphal
|
fd9c663b9a |
bpf: minimal support for programs hooked into netfilter framework
This adds minimal support for BPF_PROG_TYPE_NETFILTER bpf programs that will be invoked via the NF_HOOK() points in the ip stack. Invocation incurs an indirect call. This is not a necessity: Its possible to add 'DEFINE_BPF_DISPATCHER(nf_progs)' and handle the program invocation with the same method already done for xdp progs. This isn't done here to keep the size of this chunk down. Verifier restricts verdicts to either DROP or ACCEPT. Signed-off-by: Florian Westphal <fw@strlen.de> Link: https://lore.kernel.org/r/20230421170300.24115-3-fw@strlen.de Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Florian Westphal
|
84601d6ee6 |
bpf: add bpf_link support for BPF_NETFILTER programs
Add bpf_link support skeleton. To keep this reviewable, no bpf program
can be invoked yet, if a program is attached only a c-stub is called and
not the actual bpf program.
Defaults to 'y' if both netfilter and bpf syscall are enabled in kconfig.
Uapi example usage:
union bpf_attr attr = { };
attr.link_create.prog_fd = progfd;
attr.link_create.attach_type = 0; /* unused */
attr.link_create.netfilter.pf = PF_INET;
attr.link_create.netfilter.hooknum = NF_INET_LOCAL_IN;
attr.link_create.netfilter.priority = -128;
err = bpf(BPF_LINK_CREATE, &attr, sizeof(attr));
... this would attach progfd to ipv4:input hook.
Such hook gets removed automatically if the calling program exits.
BPF_NETFILTER program invocation is added in followup change.
NF_HOOK_OP_BPF enum will eventually be read from nfnetlink_hook, it
allows to tell userspace which program is attached at the given hook
when user runs 'nft hook list' command rather than just the priority
and not-very-helpful 'this hook runs a bpf prog but I can't tell which
one'.
Will also be used to disallow registration of two bpf programs with
same priority in a followup patch.
v4: arm32 cmpxchg only supports 32bit operand
s/prio/priority/
v3: restrict prog attachment to ip/ip6 for now, lets lift restrictions if
more use cases pop up (arptables, ebtables, netdev ingress/egress etc).
Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://lore.kernel.org/r/20230421170300.24115-2-fw@strlen.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
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Stanislav Fomichev
|
00e74ae086 |
bpf: Don't EFAULT for getsockopt with optval=NULL
Some socket options do getsockopt with optval=NULL to estimate the size
of the final buffer (which is returned via optlen). This breaks BPF
getsockopt assumptions about permitted optval buffer size. Let's enforce
these assumptions only when non-NULL optval is provided.
Fixes:
|
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Dave Marchevsky
|
4ab07209d5 |
bpf: Fix bpf_refcount_acquire's refcount_t address calculation
When calculating the address of the refcount_t struct within a local kptr, bpf_refcount_acquire_impl should add refcount_off bytes to the address of the local kptr. Due to some missing parens, the function is incorrectly adding sizeof(refcount_t) * refcount_off bytes. This patch fixes the calculation. Due to the incorrect calculation, bpf_refcount_acquire_impl was trying to refcount_inc some memory well past the end of local kptrs, resulting in kasan and refcount complaints, as reported in [0]. In that thread, Florian and Eduard discovered that bpf selftests written in the new style - with __success and an expected __retval, specifically - were not actually being run. As a result, selftests added in bpf_refcount series weren't really exercising this behavior, and thus didn't unearth the bug. With this fixed behavior it's safe to revert commit |
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Alexei Starovoitov
|
acf1c3d68e |
bpf: Fix race between btf_put and btf_idr walk.
Florian and Eduard reported hard dead lock: [ 58.433327] _raw_spin_lock_irqsave+0x40/0x50 [ 58.433334] btf_put+0x43/0x90 [ 58.433338] bpf_find_btf_id+0x157/0x240 [ 58.433353] btf_parse_fields+0x921/0x11c0 This happens since btf->refcount can be 1 at the time of btf_put() and btf_put() will call btf_free_id() which will try to grab btf_idr_lock and will dead lock. Avoid the issue by doing btf_put() without locking. Fixes: |
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Al Viro
|
1d0027dc9a |
bpf: switch to fdget_raw()
Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
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Jakub Kicinski
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681c5b51dc |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Adjacent changes: net/mptcp/protocol.h |
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Feng Zhou
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2569c7b872 |
bpf: support access variable length array of integer type
After this commit:
bpf: Support variable length array in tracing programs (
|
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Daniel Borkmann
|
71b547f561 |
bpf: Fix incorrect verifier pruning due to missing register precision taints
Juan Jose et al reported an issue found via fuzzing where the verifier's
pruning logic prematurely marks a program path as safe.
Consider the following program:
0: (b7) r6 = 1024
1: (b7) r7 = 0
2: (b7) r8 = 0
3: (b7) r9 = -2147483648
4: (97) r6 %= 1025
5: (05) goto pc+0
6: (bd) if r6 <= r9 goto pc+2
7: (97) r6 %= 1
8: (b7) r9 = 0
9: (bd) if r6 <= r9 goto pc+1
10: (b7) r6 = 0
11: (b7) r0 = 0
12: (63) *(u32 *)(r10 -4) = r0
13: (18) r4 = 0xffff888103693400 // map_ptr(ks=4,vs=48)
15: (bf) r1 = r4
16: (bf) r2 = r10
17: (07) r2 += -4
18: (85) call bpf_map_lookup_elem#1
19: (55) if r0 != 0x0 goto pc+1
20: (95) exit
21: (77) r6 >>= 10
22: (27) r6 *= 8192
23: (bf) r1 = r0
24: (0f) r0 += r6
25: (79) r3 = *(u64 *)(r0 +0)
26: (7b) *(u64 *)(r1 +0) = r3
27: (95) exit
The verifier treats this as safe, leading to oob read/write access due
to an incorrect verifier conclusion:
func#0 @0
0: R1=ctx(off=0,imm=0) R10=fp0
0: (b7) r6 = 1024 ; R6_w=1024
1: (b7) r7 = 0 ; R7_w=0
2: (b7) r8 = 0 ; R8_w=0
3: (b7) r9 = -2147483648 ; R9_w=-2147483648
4: (97) r6 %= 1025 ; R6_w=scalar()
5: (05) goto pc+0
6: (bd) if r6 <= r9 goto pc+2 ; R6_w=scalar(umin=18446744071562067969,var_off=(0xffffffff00000000; 0xffffffff)) R9_w=-2147483648
7: (97) r6 %= 1 ; R6_w=scalar()
8: (b7) r9 = 0 ; R9=0
9: (bd) if r6 <= r9 goto pc+1 ; R6=scalar(umin=1) R9=0
10: (b7) r6 = 0 ; R6_w=0
11: (b7) r0 = 0 ; R0_w=0
12: (63) *(u32 *)(r10 -4) = r0
last_idx 12 first_idx 9
regs=1 stack=0 before 11: (b7) r0 = 0
13: R0_w=0 R10=fp0 fp-8=0000????
13: (18) r4 = 0xffff8ad3886c2a00 ; R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
15: (bf) r1 = r4 ; R1_w=map_ptr(off=0,ks=4,vs=48,imm=0) R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
16: (bf) r2 = r10 ; R2_w=fp0 R10=fp0
17: (07) r2 += -4 ; R2_w=fp-4
18: (85) call bpf_map_lookup_elem#1 ; R0=map_value_or_null(id=1,off=0,ks=4,vs=48,imm=0)
19: (55) if r0 != 0x0 goto pc+1 ; R0=0
20: (95) exit
from 19 to 21: R0=map_value(off=0,ks=4,vs=48,imm=0) R6=0 R7=0 R8=0 R9=0 R10=fp0 fp-8=mmmm????
21: (77) r6 >>= 10 ; R6_w=0
22: (27) r6 *= 8192 ; R6_w=0
23: (bf) r1 = r0 ; R0=map_value(off=0,ks=4,vs=48,imm=0) R1_w=map_value(off=0,ks=4,vs=48,imm=0)
24: (0f) r0 += r6
last_idx 24 first_idx 19
regs=40 stack=0 before 23: (bf) r1 = r0
regs=40 stack=0 before 22: (27) r6 *= 8192
regs=40 stack=0 before 21: (77) r6 >>= 10
regs=40 stack=0 before 19: (55) if r0 != 0x0 goto pc+1
parent didn't have regs=40 stack=0 marks: R0_rw=map_value_or_null(id=1,off=0,ks=4,vs=48,imm=0) R6_rw=P0 R7=0 R8=0 R9=0 R10=fp0 fp-8=mmmm????
last_idx 18 first_idx 9
regs=40 stack=0 before 18: (85) call bpf_map_lookup_elem#1
regs=40 stack=0 before 17: (07) r2 += -4
regs=40 stack=0 before 16: (bf) r2 = r10
regs=40 stack=0 before 15: (bf) r1 = r4
regs=40 stack=0 before 13: (18) r4 = 0xffff8ad3886c2a00
regs=40 stack=0 before 12: (63) *(u32 *)(r10 -4) = r0
regs=40 stack=0 before 11: (b7) r0 = 0
regs=40 stack=0 before 10: (b7) r6 = 0
25: (79) r3 = *(u64 *)(r0 +0) ; R0_w=map_value(off=0,ks=4,vs=48,imm=0) R3_w=scalar()
26: (7b) *(u64 *)(r1 +0) = r3 ; R1_w=map_value(off=0,ks=4,vs=48,imm=0) R3_w=scalar()
27: (95) exit
from 9 to 11: R1=ctx(off=0,imm=0) R6=0 R7=0 R8=0 R9=0 R10=fp0
11: (b7) r0 = 0 ; R0_w=0
12: (63) *(u32 *)(r10 -4) = r0
last_idx 12 first_idx 11
regs=1 stack=0 before 11: (b7) r0 = 0
13: R0_w=0 R10=fp0 fp-8=0000????
13: (18) r4 = 0xffff8ad3886c2a00 ; R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
15: (bf) r1 = r4 ; R1_w=map_ptr(off=0,ks=4,vs=48,imm=0) R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
16: (bf) r2 = r10 ; R2_w=fp0 R10=fp0
17: (07) r2 += -4 ; R2_w=fp-4
18: (85) call bpf_map_lookup_elem#1
frame 0: propagating r6
last_idx 19 first_idx 11
regs=40 stack=0 before 18: (85) call bpf_map_lookup_elem#1
regs=40 stack=0 before 17: (07) r2 += -4
regs=40 stack=0 before 16: (bf) r2 = r10
regs=40 stack=0 before 15: (bf) r1 = r4
regs=40 stack=0 before 13: (18) r4 = 0xffff8ad3886c2a00
regs=40 stack=0 before 12: (63) *(u32 *)(r10 -4) = r0
regs=40 stack=0 before 11: (b7) r0 = 0
parent didn't have regs=40 stack=0 marks: R1=ctx(off=0,imm=0) R6_r=P0 R7=0 R8=0 R9=0 R10=fp0
last_idx 9 first_idx 9
regs=40 stack=0 before 9: (bd) if r6 <= r9 goto pc+1
parent didn't have regs=40 stack=0 marks: R1=ctx(off=0,imm=0) R6_rw=Pscalar() R7_w=0 R8_w=0 R9_rw=0 R10=fp0
last_idx 8 first_idx 0
regs=40 stack=0 before 8: (b7) r9 = 0
regs=40 stack=0 before 7: (97) r6 %= 1
regs=40 stack=0 before 6: (bd) if r6 <= r9 goto pc+2
regs=40 stack=0 before 5: (05) goto pc+0
regs=40 stack=0 before 4: (97) r6 %= 1025
regs=40 stack=0 before 3: (b7) r9 = -2147483648
regs=40 stack=0 before 2: (b7) r8 = 0
regs=40 stack=0 before 1: (b7) r7 = 0
regs=40 stack=0 before 0: (b7) r6 = 1024
19: safe
frame 0: propagating r6
last_idx 9 first_idx 0
regs=40 stack=0 before 6: (bd) if r6 <= r9 goto pc+2
regs=40 stack=0 before 5: (05) goto pc+0
regs=40 stack=0 before 4: (97) r6 %= 1025
regs=40 stack=0 before 3: (b7) r9 = -2147483648
regs=40 stack=0 before 2: (b7) r8 = 0
regs=40 stack=0 before 1: (b7) r7 = 0
regs=40 stack=0 before 0: (b7) r6 = 1024
from 6 to 9: safe
verification time 110 usec
stack depth 4
processed 36 insns (limit 1000000) max_states_per_insn 0 total_states 3 peak_states 3 mark_read 2
The verifier considers this program as safe by mistakenly pruning unsafe
code paths. In the above func#0, code lines 0-10 are of interest. In line
0-3 registers r6 to r9 are initialized with known scalar values. In line 4
the register r6 is reset to an unknown scalar given the verifier does not
track modulo operations. Due to this, the verifier can also not determine
precisely which branches in line 6 and 9 are taken, therefore it needs to
explore them both.
As can be seen, the verifier starts with exploring the false/fall-through
paths first. The 'from 19 to 21' path has both r6=0 and r9=0 and the pointer
arithmetic on r0 += r6 is therefore considered safe. Given the arithmetic,
r6 is correctly marked for precision tracking where backtracking kicks in
where it walks back the current path all the way where r6 was set to 0 in
the fall-through branch.
Next, the pruning logics pops the path 'from 9 to 11' from the stack. Also
here, the state of the registers is the same, that is, r6=0 and r9=0, so
that at line 19 the path can be pruned as it is considered safe. It is
interesting to note that the conditional in line 9 turned r6 into a more
precise state, that is, in the fall-through path at the beginning of line
10, it is R6=scalar(umin=1), and in the branch-taken path (which is analyzed
here) at the beginning of line 11, r6 turned into a known const r6=0 as
r9=0 prior to that and therefore (unsigned) r6 <= 0 concludes that r6 must
be 0 (**):
[...] ; R6_w=scalar()
9: (bd) if r6 <= r9 goto pc+1 ; R6=scalar(umin=1) R9=0
[...]
from 9 to 11: R1=ctx(off=0,imm=0) R6=0 R7=0 R8=0 R9=0 R10=fp0
[...]
The next path is 'from 6 to 9'. The verifier considers the old and current
state equivalent, and therefore prunes the search incorrectly. Looking into
the two states which are being compared by the pruning logic at line 9, the
old state consists of R6_rwD=Pscalar() R9_rwD=0 R10=fp0 and the new state
consists of R1=ctx(off=0,imm=0) R6_w=scalar(umax=18446744071562067968)
R7_w=0 R8_w=0 R9_w=-2147483648 R10=fp0. While r6 had the reg->precise flag
correctly set in the old state, r9 did not. Both r6'es are considered as
equivalent given the old one is a superset of the current, more precise one,
however, r9's actual values (0 vs 0x80000000) mismatch. Given the old r9
did not have reg->precise flag set, the verifier does not consider the
register as contributing to the precision state of r6, and therefore it
considered both r9 states as equivalent. However, for this specific pruned
path (which is also the actual path taken at runtime), register r6 will be
0x400 and r9 0x80000000 when reaching line 21, thus oob-accessing the map.
The purpose of precision tracking is to initially mark registers (including
spilled ones) as imprecise to help verifier's pruning logic finding equivalent
states it can then prune if they don't contribute to the program's safety
aspects. For example, if registers are used for pointer arithmetic or to pass
constant length to a helper, then the verifier sets reg->precise flag and
backtracks the BPF program instruction sequence and chain of verifier states
to ensure that the given register or stack slot including their dependencies
are marked as precisely tracked scalar. This also includes any other registers
and slots that contribute to a tracked state of given registers/stack slot.
This backtracking relies on recorded jmp_history and is able to traverse
entire chain of parent states. This process ends only when all the necessary
registers/slots and their transitive dependencies are marked as precise.
The backtrack_insn() is called from the current instruction up to the first
instruction, and its purpose is to compute a bitmask of registers and stack
slots that need precision tracking in the parent's verifier state. For example,
if a current instruction is r6 = r7, then r6 needs precision after this
instruction and r7 needs precision before this instruction, that is, in the
parent state. Hence for the latter r7 is marked and r6 unmarked.
For the class of jmp/jmp32 instructions, backtrack_insn() today only looks
at call and exit instructions and for all other conditionals the masks
remain as-is. However, in the given situation register r6 has a dependency
on r9 (as described above in **), so also that one needs to be marked for
precision tracking. In other words, if an imprecise register influences a
precise one, then the imprecise register should also be marked precise.
Meaning, in the parent state both dest and src register need to be tracked
for precision and therefore the marking must be more conservative by setting
reg->precise flag for both. The precision propagation needs to cover both
for the conditional: if the src reg was marked but not the dst reg and vice
versa.
After the fix the program is correctly rejected:
func#0 @0
0: R1=ctx(off=0,imm=0) R10=fp0
0: (b7) r6 = 1024 ; R6_w=1024
1: (b7) r7 = 0 ; R7_w=0
2: (b7) r8 = 0 ; R8_w=0
3: (b7) r9 = -2147483648 ; R9_w=-2147483648
4: (97) r6 %= 1025 ; R6_w=scalar()
5: (05) goto pc+0
6: (bd) if r6 <= r9 goto pc+2 ; R6_w=scalar(umin=18446744071562067969,var_off=(0xffffffff80000000; 0x7fffffff),u32_min=-2147483648) R9_w=-2147483648
7: (97) r6 %= 1 ; R6_w=scalar()
8: (b7) r9 = 0 ; R9=0
9: (bd) if r6 <= r9 goto pc+1 ; R6=scalar(umin=1) R9=0
10: (b7) r6 = 0 ; R6_w=0
11: (b7) r0 = 0 ; R0_w=0
12: (63) *(u32 *)(r10 -4) = r0
last_idx 12 first_idx 9
regs=1 stack=0 before 11: (b7) r0 = 0
13: R0_w=0 R10=fp0 fp-8=0000????
13: (18) r4 = 0xffff9290dc5bfe00 ; R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
15: (bf) r1 = r4 ; R1_w=map_ptr(off=0,ks=4,vs=48,imm=0) R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
16: (bf) r2 = r10 ; R2_w=fp0 R10=fp0
17: (07) r2 += -4 ; R2_w=fp-4
18: (85) call bpf_map_lookup_elem#1 ; R0=map_value_or_null(id=1,off=0,ks=4,vs=48,imm=0)
19: (55) if r0 != 0x0 goto pc+1 ; R0=0
20: (95) exit
from 19 to 21: R0=map_value(off=0,ks=4,vs=48,imm=0) R6=0 R7=0 R8=0 R9=0 R10=fp0 fp-8=mmmm????
21: (77) r6 >>= 10 ; R6_w=0
22: (27) r6 *= 8192 ; R6_w=0
23: (bf) r1 = r0 ; R0=map_value(off=0,ks=4,vs=48,imm=0) R1_w=map_value(off=0,ks=4,vs=48,imm=0)
24: (0f) r0 += r6
last_idx 24 first_idx 19
regs=40 stack=0 before 23: (bf) r1 = r0
regs=40 stack=0 before 22: (27) r6 *= 8192
regs=40 stack=0 before 21: (77) r6 >>= 10
regs=40 stack=0 before 19: (55) if r0 != 0x0 goto pc+1
parent didn't have regs=40 stack=0 marks: R0_rw=map_value_or_null(id=1,off=0,ks=4,vs=48,imm=0) R6_rw=P0 R7=0 R8=0 R9=0 R10=fp0 fp-8=mmmm????
last_idx 18 first_idx 9
regs=40 stack=0 before 18: (85) call bpf_map_lookup_elem#1
regs=40 stack=0 before 17: (07) r2 += -4
regs=40 stack=0 before 16: (bf) r2 = r10
regs=40 stack=0 before 15: (bf) r1 = r4
regs=40 stack=0 before 13: (18) r4 = 0xffff9290dc5bfe00
regs=40 stack=0 before 12: (63) *(u32 *)(r10 -4) = r0
regs=40 stack=0 before 11: (b7) r0 = 0
regs=40 stack=0 before 10: (b7) r6 = 0
25: (79) r3 = *(u64 *)(r0 +0) ; R0_w=map_value(off=0,ks=4,vs=48,imm=0) R3_w=scalar()
26: (7b) *(u64 *)(r1 +0) = r3 ; R1_w=map_value(off=0,ks=4,vs=48,imm=0) R3_w=scalar()
27: (95) exit
from 9 to 11: R1=ctx(off=0,imm=0) R6=0 R7=0 R8=0 R9=0 R10=fp0
11: (b7) r0 = 0 ; R0_w=0
12: (63) *(u32 *)(r10 -4) = r0
last_idx 12 first_idx 11
regs=1 stack=0 before 11: (b7) r0 = 0
13: R0_w=0 R10=fp0 fp-8=0000????
13: (18) r4 = 0xffff9290dc5bfe00 ; R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
15: (bf) r1 = r4 ; R1_w=map_ptr(off=0,ks=4,vs=48,imm=0) R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
16: (bf) r2 = r10 ; R2_w=fp0 R10=fp0
17: (07) r2 += -4 ; R2_w=fp-4
18: (85) call bpf_map_lookup_elem#1
frame 0: propagating r6
last_idx 19 first_idx 11
regs=40 stack=0 before 18: (85) call bpf_map_lookup_elem#1
regs=40 stack=0 before 17: (07) r2 += -4
regs=40 stack=0 before 16: (bf) r2 = r10
regs=40 stack=0 before 15: (bf) r1 = r4
regs=40 stack=0 before 13: (18) r4 = 0xffff9290dc5bfe00
regs=40 stack=0 before 12: (63) *(u32 *)(r10 -4) = r0
regs=40 stack=0 before 11: (b7) r0 = 0
parent didn't have regs=40 stack=0 marks: R1=ctx(off=0,imm=0) R6_r=P0 R7=0 R8=0 R9=0 R10=fp0
last_idx 9 first_idx 9
regs=40 stack=0 before 9: (bd) if r6 <= r9 goto pc+1
parent didn't have regs=240 stack=0 marks: R1=ctx(off=0,imm=0) R6_rw=Pscalar() R7_w=0 R8_w=0 R9_rw=P0 R10=fp0
last_idx 8 first_idx 0
regs=240 stack=0 before 8: (b7) r9 = 0
regs=40 stack=0 before 7: (97) r6 %= 1
regs=40 stack=0 before 6: (bd) if r6 <= r9 goto pc+2
regs=240 stack=0 before 5: (05) goto pc+0
regs=240 stack=0 before 4: (97) r6 %= 1025
regs=240 stack=0 before 3: (b7) r9 = -2147483648
regs=40 stack=0 before 2: (b7) r8 = 0
regs=40 stack=0 before 1: (b7) r7 = 0
regs=40 stack=0 before 0: (b7) r6 = 1024
19: safe
from 6 to 9: R1=ctx(off=0,imm=0) R6_w=scalar(umax=18446744071562067968) R7_w=0 R8_w=0 R9_w=-2147483648 R10=fp0
9: (bd) if r6 <= r9 goto pc+1
last_idx 9 first_idx 0
regs=40 stack=0 before 6: (bd) if r6 <= r9 goto pc+2
regs=240 stack=0 before 5: (05) goto pc+0
regs=240 stack=0 before 4: (97) r6 %= 1025
regs=240 stack=0 before 3: (b7) r9 = -2147483648
regs=40 stack=0 before 2: (b7) r8 = 0
regs=40 stack=0 before 1: (b7) r7 = 0
regs=40 stack=0 before 0: (b7) r6 = 1024
last_idx 9 first_idx 0
regs=200 stack=0 before 6: (bd) if r6 <= r9 goto pc+2
regs=240 stack=0 before 5: (05) goto pc+0
regs=240 stack=0 before 4: (97) r6 %= 1025
regs=240 stack=0 before 3: (b7) r9 = -2147483648
regs=40 stack=0 before 2: (b7) r8 = 0
regs=40 stack=0 before 1: (b7) r7 = 0
regs=40 stack=0 before 0: (b7) r6 = 1024
11: R6=scalar(umax=18446744071562067968) R9=-2147483648
11: (b7) r0 = 0 ; R0_w=0
12: (63) *(u32 *)(r10 -4) = r0
last_idx 12 first_idx 11
regs=1 stack=0 before 11: (b7) r0 = 0
13: R0_w=0 R10=fp0 fp-8=0000????
13: (18) r4 = 0xffff9290dc5bfe00 ; R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
15: (bf) r1 = r4 ; R1_w=map_ptr(off=0,ks=4,vs=48,imm=0) R4_w=map_ptr(off=0,ks=4,vs=48,imm=0)
16: (bf) r2 = r10 ; R2_w=fp0 R10=fp0
17: (07) r2 += -4 ; R2_w=fp-4
18: (85) call bpf_map_lookup_elem#1 ; R0_w=map_value_or_null(id=3,off=0,ks=4,vs=48,imm=0)
19: (55) if r0 != 0x0 goto pc+1 ; R0_w=0
20: (95) exit
from 19 to 21: R0=map_value(off=0,ks=4,vs=48,imm=0) R6=scalar(umax=18446744071562067968) R7=0 R8=0 R9=-2147483648 R10=fp0 fp-8=mmmm????
21: (77) r6 >>= 10 ; R6_w=scalar(umax=18014398507384832,var_off=(0x0; 0x3fffffffffffff))
22: (27) r6 *= 8192 ; R6_w=scalar(smax=9223372036854767616,umax=18446744073709543424,var_off=(0x0; 0xffffffffffffe000),s32_max=2147475456,u32_max=-8192)
23: (bf) r1 = r0 ; R0=map_value(off=0,ks=4,vs=48,imm=0) R1_w=map_value(off=0,ks=4,vs=48,imm=0)
24: (0f) r0 += r6
last_idx 24 first_idx 21
regs=40 stack=0 before 23: (bf) r1 = r0
regs=40 stack=0 before 22: (27) r6 *= 8192
regs=40 stack=0 before 21: (77) r6 >>= 10
parent didn't have regs=40 stack=0 marks: R0_rw=map_value(off=0,ks=4,vs=48,imm=0) R6_r=Pscalar(umax=18446744071562067968) R7=0 R8=0 R9=-2147483648 R10=fp0 fp-8=mmmm????
last_idx 19 first_idx 11
regs=40 stack=0 before 19: (55) if r0 != 0x0 goto pc+1
regs=40 stack=0 before 18: (85) call bpf_map_lookup_elem#1
regs=40 stack=0 before 17: (07) r2 += -4
regs=40 stack=0 before 16: (bf) r2 = r10
regs=40 stack=0 before 15: (bf) r1 = r4
regs=40 stack=0 before 13: (18) r4 = 0xffff9290dc5bfe00
regs=40 stack=0 before 12: (63) *(u32 *)(r10 -4) = r0
regs=40 stack=0 before 11: (b7) r0 = 0
parent didn't have regs=40 stack=0 marks: R1=ctx(off=0,imm=0) R6_rw=Pscalar(umax=18446744071562067968) R7_w=0 R8_w=0 R9_w=-2147483648 R10=fp0
last_idx 9 first_idx 0
regs=40 stack=0 before 9: (bd) if r6 <= r9 goto pc+1
regs=240 stack=0 before 6: (bd) if r6 <= r9 goto pc+2
regs=240 stack=0 before 5: (05) goto pc+0
regs=240 stack=0 before 4: (97) r6 %= 1025
regs=240 stack=0 before 3: (b7) r9 = -2147483648
regs=40 stack=0 before 2: (b7) r8 = 0
regs=40 stack=0 before 1: (b7) r7 = 0
regs=40 stack=0 before 0: (b7) r6 = 1024
math between map_value pointer and register with unbounded min value is not allowed
verification time 886 usec
stack depth 4
processed 49 insns (limit 1000000) max_states_per_insn 1 total_states 5 peak_states 5 mark_read 2
Fixes:
|
||
|
Yonghong Song
|
3be49f7955 |
bpf: Improve verifier u32 scalar equality checking
In [1], I tried to remove bpf-specific codes to prevent certain
llvm optimizations, and add llvm TTI (target transform info) hooks
to prevent those optimizations. During this process, I found
if I enable llvm SimplifyCFG:shouldFoldTwoEntryPHINode
transformation, I will hit the following verification failure with selftests:
...
8: (18) r1 = 0xffffc900001b2230 ; R1_w=map_value(off=560,ks=4,vs=564,imm=0)
10: (61) r1 = *(u32 *)(r1 +0) ; R1_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; if (skb->tstamp == EGRESS_ENDHOST_MAGIC)
11: (79) r2 = *(u64 *)(r6 +152) ; R2_w=scalar() R6=ctx(off=0,imm=0)
; if (skb->tstamp == EGRESS_ENDHOST_MAGIC)
12: (55) if r2 != 0xb9fbeef goto pc+10 ; R2_w=195018479
13: (bc) w2 = w1 ; R1_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff)) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; if (test < __NR_TESTS)
14: (a6) if w1 < 0x9 goto pc+1 16: R0=2 R1_w=scalar(umax=8,var_off=(0x0; 0xf)) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff)) R6=ctx(off=0,imm=0) R10=fp0
;
16: (27) r2 *= 28 ; R2_w=scalar(umax=120259084260,var_off=(0x0; 0x1ffffffffc),s32_max=2147483644,u32_max=-4)
17: (18) r3 = 0xffffc900001b2118 ; R3_w=map_value(off=280,ks=4,vs=564,imm=0)
19: (0f) r3 += r2 ; R2_w=scalar(umax=120259084260,var_off=(0x0; 0x1ffffffffc),s32_max=2147483644,u32_max=-4) R3_w=map_value(off=280,ks=4,vs=564,umax=120259084260,var_off=(0x0; 0x1ffffffffc),s32_max=2147483644,u32_max=-4)
20: (61) r2 = *(u32 *)(r3 +0)
R3 unbounded memory access, make sure to bounds check any such access
processed 97 insns (limit 1000000) max_states_per_insn 1 total_states 10 peak_states 10 mark_read 6
-- END PROG LOAD LOG --
libbpf: prog 'ingress_fwdns_prio100': failed to load: -13
libbpf: failed to load object 'test_tc_dtime'
libbpf: failed to load BPF skeleton 'test_tc_dtime': -13
...
At insn 14, with condition 'w1 < 9', register r1 is changed from an arbitrary
u32 value to `scalar(umax=8,var_off=(0x0; 0xf))`. Register r2, however, remains
as an arbitrary u32 value. Current verifier won't claim r1/r2 equality if
the previous mov is alu32 ('w2 = w1').
If r1 upper 32bit value is not 0, we indeed cannot clamin r1/r2 equality
after 'w2 = w1'. But in this particular case, we know r1 upper 32bit value
is 0, so it is safe to claim r1/r2 equality. This patch exactly did this.
For a 32bit subreg mov, if the src register upper 32bit is 0,
it is okay to claim equality between src and dst registers.
With this patch, the above verification sequence becomes
...
8: (18) r1 = 0xffffc9000048e230 ; R1_w=map_value(off=560,ks=4,vs=564,imm=0)
10: (61) r1 = *(u32 *)(r1 +0) ; R1_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; if (skb->tstamp == EGRESS_ENDHOST_MAGIC)
11: (79) r2 = *(u64 *)(r6 +152) ; R2_w=scalar() R6=ctx(off=0,imm=0)
; if (skb->tstamp == EGRESS_ENDHOST_MAGIC)
12: (55) if r2 != 0xb9fbeef goto pc+10 ; R2_w=195018479
13: (bc) w2 = w1 ; R1_w=scalar(id=6,umax=4294967295,var_off=(0x0; 0xffffffff)) R2_w=scalar(id=6,umax=4294967295,var_off=(0x0; 0xffffffff))
; if (test < __NR_TESTS)
14: (a6) if w1 < 0x9 goto pc+1 ; R1_w=scalar(id=6,umin=9,umax=4294967295,var_off=(0x0; 0xffffffff))
...
from 14 to 16: R0=2 R1_w=scalar(id=6,umax=8,var_off=(0x0; 0xf)) R2_w=scalar(id=6,umax=8,var_off=(0x0; 0xf)) R6=ctx(off=0,imm=0) R10=fp0
16: (27) r2 *= 28 ; R2_w=scalar(umax=224,var_off=(0x0; 0xfc))
17: (18) r3 = 0xffffc9000048e118 ; R3_w=map_value(off=280,ks=4,vs=564,imm=0)
19: (0f) r3 += r2
20: (61) r2 = *(u32 *)(r3 +0) ; R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff)) R3_w=map_value(off=280,ks=4,vs=564,umax=224,var_off=(0x0; 0xfc),s32_max=252,u32_max=252)
...
and eventually the bpf program can be verified successfully.
[1] https://reviews.llvm.org/D147968
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20230417222134.359714-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Sean Young
|
69a8c792cd |
bpf: lirc program type should not require SYS_CAP_ADMIN
Make it possible to load lirc program type with just CAP_BPF. There is nothing exceptional about lirc programs that means they require SYS_CAP_ADMIN. In order to attach or detach a lirc program type you need permission to open /dev/lirc0; if you have permission to do that, you can alter all sorts of lirc receiving options. Changing the IR protocol decoder is no different. Right now on a typical distribution /dev/lirc devices are only read/write by root. Ideally we would make them group read/write like other devices so that local users can use them without becoming root. Signed-off-by: Sean Young <sean@mess.org> Link: https://lore.kernel.org/r/ZD0ArKpwnDBJZsrE@gofer.mess.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
David Vernet
|
7b4ddf3920 |
bpf: Remove KF_KPTR_GET kfunc flag
We've managed to improve the UX for kptrs significantly over the last 9
months. All of the existing use cases which previously had KF_KPTR_GET
kfuncs (struct bpf_cpumask *, struct task_struct *, and struct cgroup *)
have all been updated to be synchronized using RCU. In other words,
their KF_KPTR_GET kfuncs have been removed in favor of KF_RCU |
KF_ACQUIRE kfuncs, with the pointers themselves also being readable from
maps in an RCU read region thanks to the types being RCU safe.
While KF_KPTR_GET was a logical starting point for kptrs, it's become
clear that they're not the correct abstraction. KF_KPTR_GET is a flag
that essentially does nothing other than enforcing that the argument to
a function is a pointer to a referenced kptr map value. At first glance,
that's a useful thing to guarantee to a kfunc. It gives kfuncs the
ability to try and acquire a reference on that kptr without requiring
the BPF prog to do something like this:
struct kptr_type *in_map, *new = NULL;
in_map = bpf_kptr_xchg(&map->value, NULL);
if (in_map) {
new = bpf_kptr_type_acquire(in_map);
in_map = bpf_kptr_xchg(&map->value, in_map);
if (in_map)
bpf_kptr_type_release(in_map);
}
That's clearly a pretty ugly (and racy) UX, and if using KF_KPTR_GET is
the only alternative, it's better than nothing. However, the problem
with any KF_KPTR_GET kfunc lies in the fact that it always requires some
kind of synchronization in order to safely do an opportunistic acquire
of the kptr in the map. This is because a BPF program running on another
CPU could do a bpf_kptr_xchg() on that map value, and free the kptr
after it's been read by the KF_KPTR_GET kfunc. For example, the
now-removed bpf_task_kptr_get() kfunc did the following:
struct task_struct *bpf_task_kptr_get(struct task_struct **pp)
{
struct task_struct *p;
rcu_read_lock();
p = READ_ONCE(*pp);
/* If p is non-NULL, it could still be freed by another CPU,
* so we have to do an opportunistic refcount_inc_not_zero()
* and return NULL if the task will be freed after the
* current RCU read region.
*/
|f (p && !refcount_inc_not_zero(&p->rcu_users))
p = NULL;
rcu_read_unlock();
return p;
}
In other words, the kfunc uses RCU to ensure that the task remains valid
after it's been peeked from the map. However, this is completely
redundant with just defining a KF_RCU kfunc that itself does a
refcount_inc_not_zero(), which is exactly what bpf_task_acquire() now
does.
So, the question of whether KF_KPTR_GET is useful is actually, "Are
there any synchronization mechanisms / safety flags that are required by
certain kptrs, but which are not provided by the verifier to kfuncs?"
The answer to that question today is "No", because every kptr we
currently care about is RCU protected.
Even if the answer ever became "yes", the proper way to support that
referenced kptr type would be to add support for whatever
synchronization mechanism it requires in the verifier, rather than
giving kfuncs a flag that says, "Here's a pointer to a referenced kptr
in a map, do whatever you need to do."
With all that said -- so as to allow us to consolidate the kfunc API,
and simplify the verifier a bit, this patch removes KF_KPTR_GET, and all
relevant logic from the verifier.
Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230416084928.326135-3-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Dave Marchevsky
|
3e81740a90 |
bpf: Centralize btf_field-specific initialization logic
All btf_fields in an object are 0-initialized by memset in
bpf_obj_init. This might not be a valid initial state for some field
types, in which case kfuncs that use the type will properly initialize
their input if it's been 0-initialized. Some BPF graph collection types
and kfuncs do this: bpf_list_{head,node} and bpf_rb_node.
An earlier patch in this series added the bpf_refcount field, for which
the 0 state indicates that the refcounted object should be free'd.
bpf_obj_init treats this field specially, setting refcount to 1 instead
of relying on scattered "refcount is 0? Must have just been initialized,
let's set to 1" logic in kfuncs.
This patch extends this treatment to list and rbtree field types,
allowing most scattered initialization logic in kfuncs to be removed.
Note that bpf_{list_head,rb_root} may be inside a BPF map, in which case
they'll be 0-initialized without passing through the newly-added logic,
so scattered initialization logic must remain for these collection root
types.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230415201811.343116-9-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Dave Marchevsky
|
404ad75a36 |
bpf: Migrate bpf_rbtree_remove to possibly fail
This patch modifies bpf_rbtree_remove to account for possible failure
due to the input rb_node already not being in any collection.
The function can now return NULL, and does when the aforementioned
scenario occurs. As before, on successful removal an owning reference to
the removed node is returned.
Adding KF_RET_NULL to bpf_rbtree_remove's kfunc flags - now KF_RET_NULL |
KF_ACQUIRE - provides the desired verifier semantics:
* retval must be checked for NULL before use
* if NULL, retval's ref_obj_id is released
* retval is a "maybe acquired" owning ref, not a non-owning ref,
so it will live past end of critical section (bpf_spin_unlock), and
thus can be checked for NULL after the end of the CS
BPF programs must add checks
============================
This does change bpf_rbtree_remove's verifier behavior. BPF program
writers will need to add NULL checks to their programs, but the
resulting UX looks natural:
bpf_spin_lock(&glock);
n = bpf_rbtree_first(&ghead);
if (!n) { /* ... */}
res = bpf_rbtree_remove(&ghead, &n->node);
bpf_spin_unlock(&glock);
if (!res) /* Newly-added check after this patch */
return 1;
n = container_of(res, /* ... */);
/* Do something else with n */
bpf_obj_drop(n);
return 0;
The "if (!res)" check above is the only addition necessary for the above
program to pass verification after this patch.
bpf_rbtree_remove no longer clobbers non-owning refs
====================================================
An issue arises when bpf_rbtree_remove fails, though. Consider this
example:
struct node_data {
long key;
struct bpf_list_node l;
struct bpf_rb_node r;
struct bpf_refcount ref;
};
long failed_sum;
void bpf_prog()
{
struct node_data *n = bpf_obj_new(/* ... */);
struct bpf_rb_node *res;
n->key = 10;
bpf_spin_lock(&glock);
bpf_list_push_back(&some_list, &n->l); /* n is now a non-owning ref */
res = bpf_rbtree_remove(&some_tree, &n->r, /* ... */);
if (!res)
failed_sum += n->key; /* not possible */
bpf_spin_unlock(&glock);
/* if (res) { do something useful and drop } ... */
}
The bpf_rbtree_remove in this example will always fail. Similarly to
bpf_spin_unlock, bpf_rbtree_remove is a non-owning reference
invalidation point. The verifier clobbers all non-owning refs after a
bpf_rbtree_remove call, so the "failed_sum += n->key" line will fail
verification, and in fact there's no good way to get information about
the node which failed to add after the invalidation. This patch removes
non-owning reference invalidation from bpf_rbtree_remove to allow the
above usecase to pass verification. The logic for why this is now
possible is as follows:
Before this series, bpf_rbtree_add couldn't fail and thus assumed that
its input, a non-owning reference, was in the tree. But it's easy to
construct an example where two non-owning references pointing to the same
underlying memory are acquired and passed to rbtree_remove one after
another (see rbtree_api_release_aliasing in
selftests/bpf/progs/rbtree_fail.c).
So it was necessary to clobber non-owning refs to prevent this
case and, more generally, to enforce "non-owning ref is definitely
in some collection" invariant. This series removes that invariant and
the failure / runtime checking added in this patch provide a clean way
to deal with the aliasing issue - just fail to remove.
Because the aliasing issue prevented by clobbering non-owning refs is no
longer an issue, this patch removes the invalidate_non_owning_refs
call from verifier handling of bpf_rbtree_remove. Note that
bpf_spin_unlock - the other caller of invalidate_non_owning_refs -
clobbers non-owning refs for a different reason, so its clobbering
behavior remains unchanged.
No BPF program changes are necessary for programs to remain valid as a
result of this clobbering change. A valid program before this patch
passed verification with its non-owning refs having shorter (or equal)
lifetimes due to more aggressive clobbering.
Also, update existing tests to check bpf_rbtree_remove retval for NULL
where necessary, and move rbtree_api_release_aliasing from
progs/rbtree_fail.c to progs/rbtree.c since it's now expected to pass
verification.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230415201811.343116-8-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Dave Marchevsky
|
d2dcc67df9 |
bpf: Migrate bpf_rbtree_add and bpf_list_push_{front,back} to possibly fail
Consider this code snippet:
struct node {
long key;
bpf_list_node l;
bpf_rb_node r;
bpf_refcount ref;
}
int some_bpf_prog(void *ctx)
{
struct node *n = bpf_obj_new(/*...*/), *m;
bpf_spin_lock(&glock);
bpf_rbtree_add(&some_tree, &n->r, /* ... */);
m = bpf_refcount_acquire(n);
bpf_rbtree_add(&other_tree, &m->r, /* ... */);
bpf_spin_unlock(&glock);
/* ... */
}
After bpf_refcount_acquire, n and m point to the same underlying memory,
and that node's bpf_rb_node field is being used by the some_tree insert,
so overwriting it as a result of the second insert is an error. In order
to properly support refcounted nodes, the rbtree and list insert
functions must be allowed to fail. This patch adds such support.
The kfuncs bpf_rbtree_add, bpf_list_push_{front,back} are modified to
return an int indicating success/failure, with 0 -> success, nonzero ->
failure.
bpf_obj_drop on failure
=======================
Currently the only reason an insert can fail is the example above: the
bpf_{list,rb}_node is already in use. When such a failure occurs, the
insert kfuncs will bpf_obj_drop the input node. This allows the insert
operations to logically fail without changing their verifier owning ref
behavior, namely the unconditional release_reference of the input
owning ref.
With insert that always succeeds, ownership of the node is always passed
to the collection, since the node always ends up in the collection.
With a possibly-failed insert w/ bpf_obj_drop, ownership of the node
is always passed either to the collection (success), or to bpf_obj_drop
(failure). Regardless, it's correct to continue unconditionally
releasing the input owning ref, as something is always taking ownership
from the calling program on insert.
Keeping owning ref behavior unchanged results in a nice default UX for
insert functions that can fail. If the program's reaction to a failed
insert is "fine, just get rid of this owning ref for me and let me go
on with my business", then there's no reason to check for failure since
that's default behavior. e.g.:
long important_failures = 0;
int some_bpf_prog(void *ctx)
{
struct node *n, *m, *o; /* all bpf_obj_new'd */
bpf_spin_lock(&glock);
bpf_rbtree_add(&some_tree, &n->node, /* ... */);
bpf_rbtree_add(&some_tree, &m->node, /* ... */);
if (bpf_rbtree_add(&some_tree, &o->node, /* ... */)) {
important_failures++;
}
bpf_spin_unlock(&glock);
}
If we instead chose to pass ownership back to the program on failed
insert - by returning NULL on success or an owning ref on failure -
programs would always have to do something with the returned ref on
failure. The most likely action is probably "I'll just get rid of this
owning ref and go about my business", which ideally would look like:
if (n = bpf_rbtree_add(&some_tree, &n->node, /* ... */))
bpf_obj_drop(n);
But bpf_obj_drop isn't allowed in a critical section and inserts must
occur within one, so in reality error handling would become a
hard-to-parse mess.
For refcounted nodes, we can replicate the "pass ownership back to
program on failure" logic with this patch's semantics, albeit in an ugly
way:
struct node *n = bpf_obj_new(/* ... */), *m;
bpf_spin_lock(&glock);
m = bpf_refcount_acquire(n);
if (bpf_rbtree_add(&some_tree, &n->node, /* ... */)) {
/* Do something with m */
}
bpf_spin_unlock(&glock);
bpf_obj_drop(m);
bpf_refcount_acquire is used to simulate "return owning ref on failure".
This should be an uncommon occurrence, though.
Addition of two verifier-fixup'd args to collection inserts
===========================================================
The actual bpf_obj_drop kfunc is
bpf_obj_drop_impl(void *, struct btf_struct_meta *), with bpf_obj_drop
macro populating the second arg with 0 and the verifier later filling in
the arg during insn fixup.
Because bpf_rbtree_add and bpf_list_push_{front,back} now might do
bpf_obj_drop, these kfuncs need a btf_struct_meta parameter that can be
passed to bpf_obj_drop_impl.
Similarly, because the 'node' param to those insert functions is the
bpf_{list,rb}_node within the node type, and bpf_obj_drop expects a
pointer to the beginning of the node, the insert functions need to be
able to find the beginning of the node struct. A second
verifier-populated param is necessary: the offset of {list,rb}_node within the
node type.
These two new params allow the insert kfuncs to correctly call
__bpf_obj_drop_impl:
beginning_of_node = bpf_rb_node_ptr - offset
if (already_inserted)
__bpf_obj_drop_impl(beginning_of_node, btf_struct_meta->record);
Similarly to other kfuncs with "hidden" verifier-populated params, the
insert functions are renamed with _impl prefix and a macro is provided
for common usage. For example, bpf_rbtree_add kfunc is now
bpf_rbtree_add_impl and bpf_rbtree_add is now a macro which sets
"hidden" args to 0.
Due to the two new args BPF progs will need to be recompiled to work
with the new _impl kfuncs.
This patch also rewrites the "hidden argument" explanation to more
directly say why the BPF program writer doesn't need to populate the
arguments with anything meaningful.
How does this new logic affect non-owning references?
=====================================================
Currently, non-owning refs are valid until the end of the critical
section in which they're created. We can make this guarantee because, if
a non-owning ref exists, the referent was added to some collection. The
collection will drop() its nodes when it goes away, but it can't go away
while our program is accessing it, so that's not a problem. If the
referent is removed from the collection in the same CS that it was added
in, it can't be bpf_obj_drop'd until after CS end. Those are the only
two ways to free the referent's memory and neither can happen until
after the non-owning ref's lifetime ends.
On first glance, having these collection insert functions potentially
bpf_obj_drop their input seems like it breaks the "can't be
bpf_obj_drop'd until after CS end" line of reasoning. But we care about
the memory not being _freed_ until end of CS end, and a previous patch
in the series modified bpf_obj_drop such that it doesn't free refcounted
nodes until refcount == 0. So the statement can be more accurately
rewritten as "can't be free'd until after CS end".
We can prove that this rewritten statement holds for any non-owning
reference produced by collection insert functions:
* If the input to the insert function is _not_ refcounted
* We have an owning reference to the input, and can conclude it isn't
in any collection
* Inserting a node in a collection turns owning refs into
non-owning, and since our input type isn't refcounted, there's no
way to obtain additional owning refs to the same underlying
memory
* Because our node isn't in any collection, the insert operation
cannot fail, so bpf_obj_drop will not execute
* If bpf_obj_drop is guaranteed not to execute, there's no risk of
memory being free'd
* Otherwise, the input to the insert function is refcounted
* If the insert operation fails due to the node's list_head or rb_root
already being in some collection, there was some previous successful
insert which passed refcount to the collection
* We have an owning reference to the input, it must have been
acquired via bpf_refcount_acquire, which bumped the refcount
* refcount must be >= 2 since there's a valid owning reference and the
node is already in a collection
* Insert triggering bpf_obj_drop will decr refcount to >= 1, never
resulting in a free
So although we may do bpf_obj_drop during the critical section, this
will never result in memory being free'd, and no changes to non-owning
ref logic are needed in this patch.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230415201811.343116-6-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Dave Marchevsky
|
7c50b1cb76 |
bpf: Add bpf_refcount_acquire kfunc
Currently, BPF programs can interact with the lifetime of refcounted
local kptrs in the following ways:
bpf_obj_new - Initialize refcount to 1 as part of new object creation
bpf_obj_drop - Decrement refcount and free object if it's 0
collection add - Pass ownership to the collection. No change to
refcount but collection is responsible for
bpf_obj_dropping it
In order to be able to add a refcounted local kptr to multiple
collections we need to be able to increment the refcount and acquire a
new owning reference. This patch adds a kfunc, bpf_refcount_acquire,
implementing such an operation.
bpf_refcount_acquire takes a refcounted local kptr and returns a new
owning reference to the same underlying memory as the input. The input
can be either owning or non-owning. To reinforce why this is safe,
consider the following code snippets:
struct node *n = bpf_obj_new(typeof(*n)); // A
struct node *m = bpf_refcount_acquire(n); // B
In the above snippet, n will be alive with refcount=1 after (A), and
since nothing changes that state before (B), it's obviously safe. If
n is instead added to some rbtree, we can still safely refcount_acquire
it:
struct node *n = bpf_obj_new(typeof(*n));
struct node *m;
bpf_spin_lock(&glock);
bpf_rbtree_add(&groot, &n->node, less); // A
m = bpf_refcount_acquire(n); // B
bpf_spin_unlock(&glock);
In the above snippet, after (A) n is a non-owning reference, and after
(B) m is an owning reference pointing to the same memory as n. Although
n has no ownership of that memory's lifetime, it's guaranteed to be
alive until the end of the critical section, and n would be clobbered if
we were past the end of the critical section, so it's safe to bump
refcount.
Implementation details:
* From verifier's perspective, bpf_refcount_acquire handling is similar
to bpf_obj_new and bpf_obj_drop. Like the former, it returns a new
owning reference matching input type, although like the latter, type
can be inferred from concrete kptr input. Verifier changes in
{check,fixup}_kfunc_call and check_kfunc_args are largely copied from
aforementioned functions' verifier changes.
* An exception to the above is the new KF_ARG_PTR_TO_REFCOUNTED_KPTR
arg, indicated by new "__refcounted_kptr" kfunc arg suffix. This is
necessary in order to handle both owning and non-owning input without
adding special-casing to "__alloc" arg handling. Also a convenient
place to confirm that input type has bpf_refcount field.
* The implemented kfunc is actually bpf_refcount_acquire_impl, with
'hidden' second arg that the verifier sets to the type's struct_meta
in fixup_kfunc_call.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230415201811.343116-5-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Dave Marchevsky
|
1512217c47 |
bpf: Support refcounted local kptrs in existing semantics
A local kptr is considered 'refcounted' when it is of a type that has a bpf_refcount field. When such a kptr is created, its refcount should be initialized to 1; when destroyed, the object should be free'd only if a refcount decr results in 0 refcount. Existing logic always frees the underlying memory when destroying a local kptr, and 0-initializes all btf_record fields. This patch adds checks for "is local kptr refcounted?" and new logic for that case in the appropriate places. This patch focuses on changing existing semantics and thus conspicuously does _not_ provide a way for BPF programs in increment refcount. That follows later in the series. __bpf_obj_drop_impl is modified to do the right thing when it sees a refcounted type. Container types for graph nodes (list, tree, stashed in map) are migrated to use __bpf_obj_drop_impl as a destructor for their nodes instead of each having custom destruction code in their _free paths. Now that "drop" isn't a synonym for "free" when the type is refcounted it makes sense to centralize this logic. Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/r/20230415201811.343116-4-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Dave Marchevsky
|
d54730b50b |
bpf: Introduce opaque bpf_refcount struct and add btf_record plumbing
A 'struct bpf_refcount' is added to the set of opaque uapi/bpf.h types meant for use in BPF programs. Similarly to other opaque types like bpf_spin_lock and bpf_rbtree_node, the verifier needs to know where in user-defined struct types a bpf_refcount can be located, so necessary btf_record plumbing is added to enable this. bpf_refcount is sized to hold a refcount_t. Similarly to bpf_spin_lock, the offset of a bpf_refcount is cached in btf_record as refcount_off in addition to being in the field array. Caching refcount_off makes sense for this field because further patches in the series will modify functions that take local kptrs (e.g. bpf_obj_drop) to change their behavior if the type they're operating on is refcounted. So enabling fast "is this type refcounted?" checks is desirable. No such verifier behavior changes are introduced in this patch, just logic to recognize 'struct bpf_refcount' in btf_record. Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/r/20230415201811.343116-3-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Dave Marchevsky
|
cd2a807901 |
bpf: Remove btf_field_offs, use btf_record's fields instead
The btf_field_offs struct contains (offset, size) for btf_record fields,
sorted by offset. btf_field_offs is always used in conjunction with
btf_record, which has btf_field 'fields' array with (offset, type), the
latter of which btf_field_offs' size is derived from via
btf_field_type_size.
This patch adds a size field to struct btf_field and sorts btf_record's
fields by offset, making it possible to get rid of btf_field_offs. Less
data duplication and less code complexity results.
Since btf_field_offs' lifetime closely followed the btf_record used to
populate it, most complexity wins are from removal of initialization
code like:
if (btf_record_successfully_initialized) {
foffs = btf_parse_field_offs(rec);
if (IS_ERR_OR_NULL(foffs))
// free the btf_record and return err
}
Other changes in this patch are pretty mechanical:
* foffs->field_off[i] -> rec->fields[i].offset
* foffs->field_sz[i] -> rec->fields[i].size
* Sort rec->fields in btf_parse_fields before returning
* It's possible that this is necessary independently of other
changes in this patch. btf_record_find in syscall.c expects
btf_record's fields to be sorted by offset, yet there's no
explicit sorting of them before this patch, record's fields are
populated in the order they're read from BTF struct definition.
BTF docs don't say anything about the sortedness of struct fields.
* All functions taking struct btf_field_offs * input now instead take
struct btf_record *. All callsites of these functions already have
access to the correct btf_record.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230415201811.343116-2-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Ilya Leoshkevich
|
1cf3bfc60f |
bpf: Support 64-bit pointers to kfuncs
test_ksyms_module fails to emit a kfunc call targeting a module on s390x, because the verifier stores the difference between kfunc address and __bpf_call_base in bpf_insn.imm, which is s32, and modules are roughly (1 << 42) bytes away from the kernel on s390x. Fix by keeping BTF id in bpf_insn.imm for BPF_PSEUDO_KFUNC_CALLs, and storing the absolute address in bpf_kfunc_desc. Introduce bpf_jit_supports_far_kfunc_call() in order to limit this new behavior to the s390x JIT. Otherwise other JITs need to be modified, which is not desired. Introduce bpf_get_kfunc_addr() instead of exposing both find_kfunc_desc() and struct bpf_kfunc_desc. In addition to sorting kfuncs by imm, also sort them by offset, in order to handle conflicting imms from different modules. Do this on all architectures in order to simplify code. Factor out resolving specialized kfuncs (XPD and dynptr) from fixup_kfunc_call(). This was required in the first place, because fixup_kfunc_call() uses find_kfunc_desc(), which returns a const pointer, so it's not possible to modify kfunc addr without stripping const, which is not nice. It also removes repetition of code like: if (bpf_jit_supports_far_kfunc_call()) desc->addr = func; else insn->imm = BPF_CALL_IMM(func); and separates kfunc_desc_tab fixups from kfunc_call fixups. Suggested-by: Jiri Olsa <olsajiri@gmail.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20230412230632.885985-1-iii@linux.ibm.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Yafang
|
c11bd04648 |
bpf: Add preempt_count_{sub,add} into btf id deny list
The recursion check in __bpf_prog_enter* and __bpf_prog_exit*
leave preempt_count_{sub,add} unprotected. When attaching trampoline to
them we get panic as follows,
[ 867.843050] BUG: TASK stack guard page was hit at 0000000009d325cf (stack is 0000000046a46a15..00000000537e7b28)
[ 867.843064] stack guard page: 0000 [#1] PREEMPT SMP NOPTI
[ 867.843067] CPU: 8 PID: 11009 Comm: trace Kdump: loaded Not tainted 6.2.0+ #4
[ 867.843100] Call Trace:
[ 867.843101] <TASK>
[ 867.843104] asm_exc_int3+0x3a/0x40
[ 867.843108] RIP: 0010:preempt_count_sub+0x1/0xa0
[ 867.843135] __bpf_prog_enter_recur+0x17/0x90
[ 867.843148] bpf_trampoline_6442468108_0+0x2e/0x1000
[ 867.843154] ? preempt_count_sub+0x1/0xa0
[ 867.843157] preempt_count_sub+0x5/0xa0
[ 867.843159] ? migrate_enable+0xac/0xf0
[ 867.843164] __bpf_prog_exit_recur+0x2d/0x40
[ 867.843168] bpf_trampoline_6442468108_0+0x55/0x1000
...
[ 867.843788] preempt_count_sub+0x5/0xa0
[ 867.843793] ? migrate_enable+0xac/0xf0
[ 867.843829] __bpf_prog_exit_recur+0x2d/0x40
[ 867.843837] BUG: IRQ stack guard page was hit at 0000000099bd8228 (stack is 00000000b23e2bc4..000000006d95af35)
[ 867.843841] BUG: IRQ stack guard page was hit at 000000005ae07924 (stack is 00000000ffd69623..0000000014eb594c)
[ 867.843843] BUG: IRQ stack guard page was hit at 00000000028320f0 (stack is 00000000034b6438..0000000078d1bcec)
[ 867.843842] bpf_trampoline_6442468108_0+0x55/0x1000
...
That is because in __bpf_prog_exit_recur, the preempt_count_{sub,add} are
called after prog->active is decreased.
Fixing this by adding these two functions into btf ids deny list.
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Yafang <laoar.shao@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Acked-by: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/r/20230413025248.79764-1-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Jakub Kicinski
|
c2865b1122 |
bpf-next-for-netdev
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Daniel Borkmann says:
====================
pull-request: bpf-next 2023-04-13
We've added 260 non-merge commits during the last 36 day(s) which contain
a total of 356 files changed, 21786 insertions(+), 11275 deletions(-).
The main changes are:
1) Rework BPF verifier log behavior and implement it as a rotating log
by default with the option to retain old-style fixed log behavior,
from Andrii Nakryiko.
2) Adds support for using {FOU,GUE} encap with an ipip device operating
in collect_md mode and add a set of BPF kfuncs for controlling encap
params, from Christian Ehrig.
3) Allow BPF programs to detect at load time whether a particular kfunc
exists or not, and also add support for this in light skeleton,
from Alexei Starovoitov.
4) Optimize hashmap lookups when key size is multiple of 4,
from Anton Protopopov.
5) Enable RCU semantics for task BPF kptrs and allow referenced kptr
tasks to be stored in BPF maps, from David Vernet.
6) Add support for stashing local BPF kptr into a map value via
bpf_kptr_xchg(). This is useful e.g. for rbtree node creation
for new cgroups, from Dave Marchevsky.
7) Fix BTF handling of is_int_ptr to skip modifiers to work around
tracing issues where a program cannot be attached, from Feng Zhou.
8) Migrate a big portion of test_verifier unit tests over to
test_progs -a verifier_* via inline asm to ease {read,debug}ability,
from Eduard Zingerman.
9) Several updates to the instruction-set.rst documentation
which is subject to future IETF standardization
(https://lwn.net/Articles/926882/), from Dave Thaler.
10) Fix BPF verifier in the __reg_bound_offset's 64->32 tnum sub-register
known bits information propagation, from Daniel Borkmann.
11) Add skb bitfield compaction work related to BPF with the overall goal
to make more of the sk_buff bits optional, from Jakub Kicinski.
12) BPF selftest cleanups for build id extraction which stand on its own
from the upcoming integration work of build id into struct file object,
from Jiri Olsa.
13) Add fixes and optimizations for xsk descriptor validation and several
selftest improvements for xsk sockets, from Kal Conley.
14) Add BPF links for struct_ops and enable switching implementations
of BPF TCP cong-ctls under a given name by replacing backing
struct_ops map, from Kui-Feng Lee.
15) Remove a misleading BPF verifier env->bypass_spec_v1 check on variable
offset stack read as earlier Spectre checks cover this,
from Luis Gerhorst.
16) Fix issues in copy_from_user_nofault() for BPF and other tracers
to resemble copy_from_user_nmi() from safety PoV, from Florian Lehner
and Alexei Starovoitov.
17) Add --json-summary option to test_progs in order for CI tooling to
ease parsing of test results, from Manu Bretelle.
18) Batch of improvements and refactoring to prep for upcoming
bpf_local_storage conversion to bpf_mem_cache_{alloc,free} allocator,
from Martin KaFai Lau.
19) Improve bpftool's visual program dump which produces the control
flow graph in a DOT format by adding C source inline annotations,
from Quentin Monnet.
20) Fix attaching fentry/fexit/fmod_ret/lsm to modules by extracting
the module name from BTF of the target and searching kallsyms of
the correct module, from Viktor Malik.
21) Improve BPF verifier handling of '<const> <cond> <non_const>'
to better detect whether in particular jmp32 branches are taken,
from Yonghong Song.
22) Allow BPF TCP cong-ctls to write app_limited of struct tcp_sock.
A built-in cc or one from a kernel module is already able to write
to app_limited, from Yixin Shen.
Conflicts:
Documentation/bpf/bpf_devel_QA.rst
|
||
|
David Vernet
|
6499fe6edc |
bpf: Remove bpf_cgroup_kptr_get() kfunc
Now that bpf_cgroup_acquire() is KF_RCU | KF_RET_NULL, bpf_cgroup_kptr_get() is redundant. Let's remove it, and update selftests to instead use bpf_cgroup_acquire() where appropriate. The next patch will update the BPF documentation to not mention bpf_cgroup_kptr_get(). Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230411041633.179404-2-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
David Vernet
|
1d71283987 |
bpf: Make bpf_cgroup_acquire() KF_RCU | KF_RET_NULL
struct cgroup is already an RCU-safe type in the verifier. We can therefore update bpf_cgroup_acquire() to be KF_RCU | KF_RET_NULL, and subsequently remove bpf_cgroup_kptr_get(). This patch does the first of these by updating bpf_cgroup_acquire() to be KF_RCU | KF_RET_NULL, and also updates selftests accordingly. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230411041633.179404-1-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Alexei Starovoitov
|
10fd5f70c3 |
bpf: Handle NULL in bpf_local_storage_free.
During OOM bpf_local_storage_alloc() may fail to allocate 'storage' and
call to bpf_local_storage_free() with NULL pointer will cause a crash like:
[ 271718.917646] BUG: kernel NULL pointer dereference, address: 00000000000000a0
[ 271719.019620] RIP: 0010:call_rcu+0x2d/0x240
[ 271719.216274] bpf_local_storage_alloc+0x19e/0x1e0
[ 271719.250121] bpf_local_storage_update+0x33b/0x740
Fixes:
|
||
|
Feng Zhou
|
91f2dc6838 |
bpf/btf: Fix is_int_ptr()
When tracing a kernel function with arg type is u32*, btf_ctx_access() would report error: arg2 type INT is not a struct. The commit |
||
|
Andrii Nakryiko
|
fac08d45e2 |
bpf: Relax log_buf NULL conditions when log_level>0 is requested
Drop the log_size>0 and log_buf!=NULL condition when log_level>0. This allows users to request log_true_size of a full log without providing actual (even if small) log buffer. Verifier log handling code was mostly ready to handle NULL log->ubuf, so only few small changes were necessary to prevent NULL log->ubuf from causing problems. Note, that if user provided NULL log_buf with log_level>0 we don't consider this a log truncation, and thus won't return -ENOSPC. We also enforce that either (log_buf==NULL && log_size==0) or (log_buf!=NULL && log_size>0). Suggested-by: Lorenz Bauer <lmb@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Lorenz Bauer <lmb@isovalent.com> Link: https://lore.kernel.org/bpf/20230406234205.323208-15-andrii@kernel.org |
||
|
Andrii Nakryiko
|
bdcab4144f |
bpf: Simplify internal verifier log interface
Simplify internal verifier log API down to bpf_vlog_init() and bpf_vlog_finalize(). The former handles input arguments validation in one place and makes it easier to change it. The latter subsumes -ENOSPC (truncation) and -EFAULT handling and simplifies both caller's code (bpf_check() and btf_parse()). For btf_parse(), this patch also makes sure that verifier log finalization happens even if there is some error condition during BTF verification process prior to normal finalization step. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Lorenz Bauer <lmb@isovalent.com> Link: https://lore.kernel.org/bpf/20230406234205.323208-14-andrii@kernel.org |
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Andrii Nakryiko
|
47a71c1f9a |
bpf: Add log_true_size output field to return necessary log buffer size
Add output-only log_true_size and btf_log_true_size field to BPF_PROG_LOAD and BPF_BTF_LOAD commands, respectively. It will return the size of log buffer necessary to fit in all the log contents at specified log_level. This is very useful for BPF loader libraries like libbpf to be able to size log buffer correctly, but could be used by users directly, if necessary, as well. This patch plumbs all this through the code, taking into account actual bpf_attr size provided by user to determine if these new fields are expected by users. And if they are, set them from kernel on return. We refactory btf_parse() function to accommodate this, moving attr and uattr handling inside it. The rest is very straightforward code, which is split from the logging accounting changes in the previous patch to make it simpler to review logic vs UAPI changes. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Lorenz Bauer <lmb@isovalent.com> Link: https://lore.kernel.org/bpf/20230406234205.323208-13-andrii@kernel.org |
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Andrii Nakryiko
|
fa1c7d5cc4 |
bpf: Keep track of total log content size in both fixed and rolling modes
Change how we do accounting in BPF_LOG_FIXED mode and adopt log->end_pos as *logical* log position. This means that we can go beyond physical log buffer size now and be able to tell what log buffer size should be to fit entire log contents without -ENOSPC. To do this for BPF_LOG_FIXED mode, we need to remove a short-circuiting logic of not vsnprintf()'ing further log content once we filled up user-provided buffer, which is done by bpf_verifier_log_needed() checks. We modify these checks to always keep going if log->level is non-zero (i.e., log is requested), even if log->ubuf was NULL'ed out due to copying data to user-space, or if entire log buffer is physically full. We adopt bpf_verifier_vlog() routine to work correctly with log->ubuf == NULL condition, performing log formatting into temporary kernel buffer, doing all the necessary accounting, but just avoiding copying data out if buffer is full or NULL'ed out. With these changes, it's now possible to do this sort of determination of log contents size in both BPF_LOG_FIXED and default rolling log mode. We need to keep in mind bpf_vlog_reset(), though, which shrinks log contents after successful verification of a particular code path. This log reset means that log->end_pos isn't always increasing, so to return back to users what should be the log buffer size to fit all log content without causing -ENOSPC even in the presence of log resetting, we need to keep maximum over "lifetime" of logging. We do this accounting in bpf_vlog_update_len_max() helper. A related and subtle aspect is that with this logical log->end_pos even in BPF_LOG_FIXED mode we could temporary "overflow" buffer, but then reset it back with bpf_vlog_reset() to a position inside user-supplied log_buf. In such situation we still want to properly maintain terminating zero. We will eventually return -ENOSPC even if final log buffer is small (we detect this through log->len_max check). This behavior is simpler to reason about and is consistent with current behavior of verifier log. Handling of this required a small addition to bpf_vlog_reset() logic to avoid doing put_user() beyond physical log buffer dimensions. Another issue to keep in mind is that we limit log buffer size to 32-bit value and keep such log length as u32, but theoretically verifier could produce huge log stretching beyond 4GB. Instead of keeping (and later returning) 64-bit log length, we cap it at UINT_MAX. Current UAPI makes it impossible to specify log buffer size bigger than 4GB anyways, so we don't really loose anything here and keep everything consistently 32-bit in UAPI. This property will be utilized in next patch. Doing the same determination of maximum log buffer for rolling mode is trivial, as log->end_pos and log->start_pos are already logical positions, so there is nothing new there. These changes do incidentally fix one small issue with previous logging logic. Previously, if use provided log buffer of size N, and actual log output was exactly N-1 bytes + terminating \0, kernel logic coun't distinguish this condition from log truncation scenario which would end up with truncated log contents of N-1 bytes + terminating \0 as well. But now with log->end_pos being logical position that could go beyond actual log buffer size, we can distinguish these two conditions, which we do in this patch. This plays nicely with returning log_size_actual (implemented in UAPI in the next patch), as we can now guarantee that if user takes such log_size_actual and provides log buffer of that exact size, they will not get -ENOSPC in return. All in all, all these changes do conceptually unify fixed and rolling log modes much better, and allow a nice feature requested by users: knowing what should be the size of the buffer to avoid -ENOSPC. We'll plumb this through the UAPI and the code in the next patch. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Lorenz Bauer <lmb@isovalent.com> Link: https://lore.kernel.org/bpf/20230406234205.323208-12-andrii@kernel.org |
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Andrii Nakryiko
|
8a6ca6bc55 |
bpf: Simplify logging-related error conditions handling
Move log->level == 0 check into bpf_vlog_truncated() instead of doing it explicitly. Also remove unnecessary goto in kernel/bpf/verifier.c. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Lorenz Bauer <lmb@isovalent.com> Link: https://lore.kernel.org/bpf/20230406234205.323208-11-andrii@kernel.org |
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Andrii Nakryiko
|
cbedb42a0d |
bpf: Avoid incorrect -EFAULT error in BPF_LOG_KERNEL mode
If verifier log is in BPF_LOG_KERNEL mode, no log->ubuf is expected and it stays NULL throughout entire verification process. Don't erroneously return -EFAULT in such case. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Lorenz Bauer <lmb@isovalent.com> Link: https://lore.kernel.org/bpf/20230406234205.323208-10-andrii@kernel.org |
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Andrii Nakryiko
|
971fb5057d |
bpf: Fix missing -EFAULT return on user log buf error in btf_parse()
btf_parse() is missing -EFAULT error return if log->ubuf was NULL-ed out due to error while copying data into user-provided buffer. Add it, but handle a special case of BPF_LOG_KERNEL in which log->ubuf is always NULL. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Lorenz Bauer <lmb@isovalent.com> Link: https://lore.kernel.org/bpf/20230406234205.323208-9-andrii@kernel.org |
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Andrii Nakryiko
|
24bc80887a |
bpf: Ignore verifier log reset in BPF_LOG_KERNEL mode
Verifier log position reset is meaningless in BPF_LOG_KERNEL mode, so just exit early in bpf_vlog_reset() if log->level is BPF_LOG_KERNEL. This avoid meaningless put_user() into NULL log->ubuf. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Lorenz Bauer <lmb@isovalent.com> Link: https://lore.kernel.org/bpf/20230406234205.323208-8-andrii@kernel.org |
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Andrii Nakryiko
|
1216640938 |
bpf: Switch BPF verifier log to be a rotating log by default
Currently, if user-supplied log buffer to collect BPF verifier log turns out to be too small to contain full log, bpf() syscall returns -ENOSPC, fails BPF program verification/load, and preserves first N-1 bytes of the verifier log (where N is the size of user-supplied buffer). This is problematic in a bunch of common scenarios, especially when working with real-world BPF programs that tend to be pretty complex as far as verification goes and require big log buffers. Typically, it's when debugging tricky cases at log level 2 (verbose). Also, when BPF program is successfully validated, log level 2 is the only way to actually see verifier state progression and all the important details. Even with log level 1, it's possible to get -ENOSPC even if the final verifier log fits in log buffer, if there is a code path that's deep enough to fill up entire log, even if normally it would be reset later on (there is a logic to chop off successfully validated portions of BPF verifier log). In short, it's not always possible to pre-size log buffer. Also, what's worse, in practice, the end of the log most often is way more important than the beginning, but verifier stops emitting log as soon as initial log buffer is filled up. This patch switches BPF verifier log behavior to effectively behave as rotating log. That is, if user-supplied log buffer turns out to be too short, verifier will keep overwriting previously written log, effectively treating user's log buffer as a ring buffer. -ENOSPC is still going to be returned at the end, to notify user that log contents was truncated, but the important last N bytes of the log would be returned, which might be all that user really needs. This consistent -ENOSPC behavior, regardless of rotating or fixed log behavior, allows to prevent backwards compatibility breakage. The only user-visible change is which portion of verifier log user ends up seeing *if buffer is too small*. Given contents of verifier log itself is not an ABI, there is no breakage due to this behavior change. Specialized tools that rely on specific contents of verifier log in -ENOSPC scenario are expected to be easily adapted to accommodate old and new behaviors. Importantly, though, to preserve good user experience and not require every user-space application to adopt to this new behavior, before exiting to user-space verifier will rotate log (in place) to make it start at the very beginning of user buffer as a continuous zero-terminated string. The contents will be a chopped off N-1 last bytes of full verifier log, of course. Given beginning of log is sometimes important as well, we add BPF_LOG_FIXED (which equals 8) flag to force old behavior, which allows tools like veristat to request first part of verifier log, if necessary. BPF_LOG_FIXED flag is also a simple and straightforward way to check if BPF verifier supports rotating behavior. On the implementation side, conceptually, it's all simple. We maintain 64-bit logical start and end positions. If we need to truncate the log, start position will be adjusted accordingly to lag end position by N bytes. We then use those logical positions to calculate their matching actual positions in user buffer and handle wrap around the end of the buffer properly. Finally, right before returning from bpf_check(), we rotate user log buffer contents in-place as necessary, to make log contents contiguous. See comments in relevant functions for details. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Lorenz Bauer <lmb@isovalent.com> Link: https://lore.kernel.org/bpf/20230406234205.323208-4-andrii@kernel.org |
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Andrii Nakryiko
|
03cc3aa6a5 |
bpf: Remove minimum size restrictions on verifier log buffer
It's not clear why we have 128 as minimum size, but it makes testing harder and seems unnecessary, as we carefully handle truncation scenarios and use proper snprintf variants. So remove this limitation and just enforce positive length for log buffer. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Lorenz Bauer <lmb@isovalent.com> Link: https://lore.kernel.org/bpf/20230406234205.323208-3-andrii@kernel.org |
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Andrii Nakryiko
|
4294a0a7ab |
bpf: Split off basic BPF verifier log into separate file
kernel/bpf/verifier.c file is large and growing larger all the time. So it's good to start splitting off more or less self-contained parts into separate files to keep source code size (somewhat) somewhat under control. This patch is a one step in this direction, moving some of BPF verifier log routines into a separate kernel/bpf/log.c. Right now it's most low-level and isolated routines to append data to log, reset log to previous position, etc. Eventually we could probably move verifier state printing logic here as well, but this patch doesn't attempt to do that yet. Subsequent patches will add more logic to verifier log management, so having basics in a separate file will make sure verifier.c doesn't grow more with new changes. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Lorenz Bauer <lmb@isovalent.com> Link: https://lore.kernel.org/bpf/20230406234205.323208-2-andrii@kernel.org |
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Barret Rhoden
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f3f2134977 |
bpf: ensure all memory is initialized in bpf_get_current_comm
BPF helpers that take an ARG_PTR_TO_UNINIT_MEM must ensure that all of the memory is set, including beyond the end of the string. Signed-off-by: Barret Rhoden <brho@google.com> Link: https://lore.kernel.org/r/20230407001808.1622968-1-brho@google.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Yonghong Song
|
953d9f5bea |
bpf: Improve handling of pattern '<const> <cond_op> <non_const>' in verifier
Currently, the verifier does not handle '<const> <cond_op> <non_const>' well. For example, ... 10: (79) r1 = *(u64 *)(r10 -16) ; R1_w=scalar() R10=fp0 11: (b7) r2 = 0 ; R2_w=0 12: (2d) if r2 > r1 goto pc+2 13: (b7) r0 = 0 14: (95) exit 15: (65) if r1 s> 0x1 goto pc+3 16: (0f) r0 += r1 ... At insn 12, verifier decides both true and false branch are possible, but actually only false branch is possible. Currently, the verifier already supports patterns '<non_const> <cond_op> <const>. Add support for patterns '<const> <cond_op> <non_const>' in a similar way. Also fix selftest 'verifier_bounds_mix_sign_unsign/bounds checks mixing signed and unsigned, variant 10' due to this change. Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Dave Marchevsky <davemarchevsky@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230406164505.1046801-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Yonghong Song
|
13fbcee557 |
bpf: Improve verifier JEQ/JNE insn branch taken checking
Currently, for BPF_JEQ/BPF_JNE insn, verifier determines whether the branch is taken or not only if both operands are constants. Therefore, for the following code snippet, 0: (85) call bpf_ktime_get_ns#5 ; R0_w=scalar() 1: (a5) if r0 < 0x3 goto pc+2 ; R0_w=scalar(umin=3) 2: (b7) r2 = 2 ; R2_w=2 3: (1d) if r0 == r2 goto pc+2 6 At insn 3, since r0 is not a constant, verifier assumes both branch can be taken which may lead inproper verification failure. Add comparing umin/umax value and the constant. If the umin value is greater than the constant, or umax value is smaller than the constant, for JEQ the branch must be not-taken, and for JNE the branch must be taken. The jmp32 mode JEQ/JNE branch taken checking is also handled similarly. The following lists the veristat result w.r.t. changed number of processes insns during verification: File Program Insns (A) Insns (B) Insns (DIFF) ----------------------------------------------------- ---------------------------------------------------- --------- --------- --------------- test_cls_redirect.bpf.linked3.o cls_redirect 64980 73472 +8492 (+13.07%) test_seg6_loop.bpf.linked3.o __add_egr_x 12425 12423 -2 (-0.02%) test_tcp_hdr_options.bpf.linked3.o estab 2634 2558 -76 (-2.89%) test_parse_tcp_hdr_opt.bpf.linked3.o xdp_ingress_v6 1421 1420 -1 (-0.07%) test_parse_tcp_hdr_opt_dynptr.bpf.linked3.o xdp_ingress_v6 1238 1237 -1 (-0.08%) test_tc_dtime.bpf.linked3.o egress_fwdns_prio100 414 411 -3 (-0.72%) Mostly a small improvement but test_cls_redirect.bpf.linked3.o has a 13% regression. I checked with verifier log and found it this is due to pruning. For some JEQ/JNE branches impacted by this patch, one branch is explored and the other has state equivalence and pruned. Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Dave Marchevsky <davemarchevsky@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230406164455.1045294-1-yhs@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Alexei Starovoitov
|
afeebf9f57 |
bpf: Undo strict enforcement for walking untagged fields.
The commit |
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Alexei Starovoitov
|
30ee9821f9 |
bpf: Allowlist few fields similar to __rcu tag.
Allow bpf program access cgrp->kn, mm->exe_file, skb->sk, req->sk. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/20230404045029.82870-7-alexei.starovoitov@gmail.com |
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Alexei Starovoitov
|
add68b843f |
bpf: Refactor NULL-ness check in check_reg_type().
check_reg_type() unconditionally disallows PTR_TO_BTF_ID | PTR_MAYBE_NULL. It's problematic for helpers that allow ARG_PTR_TO_BTF_ID_OR_NULL like bpf_sk_storage_get(). Allow passing PTR_TO_BTF_ID | PTR_MAYBE_NULL into such helpers. That technically includes bpf_kptr_xchg() helper, but in practice: bpf_kptr_xchg(..., bpf_cpumask_create()); is still disallowed because bpf_cpumask_create() returns ref counted pointer with ref_obj_id > 0. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/20230404045029.82870-6-alexei.starovoitov@gmail.com |
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Alexei Starovoitov
|
91571a515d |
bpf: Teach verifier that certain helpers accept NULL pointer.
bpf_[sk|inode|task|cgrp]_storage_[get|delete]() and bpf_get_socket_cookie() helpers perform run-time check that sk|inode|task|cgrp pointer != NULL. Teach verifier about this fact and allow bpf programs to pass PTR_TO_BTF_ID | PTR_MAYBE_NULL into such helpers. It will be used in the subsequent patch that will do bpf_sk_storage_get(.., skb->sk, ...); Even when 'skb' pointer is trusted the 'sk' pointer may be NULL. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/20230404045029.82870-5-alexei.starovoitov@gmail.com |
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Alexei Starovoitov
|
63260df139 |
bpf: Refactor btf_nested_type_is_trusted().
btf_nested_type_is_trusted() tries to find a struct member at corresponding offset.
It works for flat structures and falls apart in more complex structs with nested structs.
The offset->member search is already performed by btf_struct_walk() including nested structs.
Reuse this work and pass {field name, field btf id} into btf_nested_type_is_trusted()
instead of offset to make BTF_TYPE_SAFE*() logic more robust.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/bpf/20230404045029.82870-4-alexei.starovoitov@gmail.com
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Alexei Starovoitov
|
b7e852a9ec |
bpf: Remove unused arguments from btf_struct_access().
Remove unused arguments from btf_struct_access() callback. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/20230404045029.82870-3-alexei.starovoitov@gmail.com |
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Alexei Starovoitov
|
7d64c51328 |
bpf: Invoke btf_struct_access() callback only for writes.
Remove duplicated if (atype == BPF_READ) btf_struct_access() from btf_struct_access() callback and invoke it only for writes. This is possible to do because currently btf_struct_access() custom callback always delegates to generic btf_struct_access() helper for BPF_READ accesses. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/20230404045029.82870-2-alexei.starovoitov@gmail.com |
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Dave Marchevsky
|
f6a6a5a976 |
bpf: Fix struct_meta lookup for bpf_obj_free_fields kfunc call
bpf_obj_drop_impl has a void return type. In check_kfunc_call, the "else
if" which sets insn_aux->kptr_struct_meta for bpf_obj_drop_impl is
surrounded by a larger if statement which checks btf_type_is_ptr. As a
result:
* The bpf_obj_drop_impl-specific code will never execute
* The btf_struct_meta input to bpf_obj_drop is always NULL
* __bpf_obj_drop_impl will always see a NULL btf_record when called
from BPF program, and won't call bpf_obj_free_fields
* program-allocated kptrs which have fields that should be cleaned up
by bpf_obj_free_fields may instead leak resources
This patch adds a btf_type_is_void branch to the larger if and moves
special handling for bpf_obj_drop_impl there, fixing the issue.
Fixes:
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Anton Protopopov
|
92b2e810f0 |
bpf: compute hashes in bloom filter similar to hashmap
If the value size in a bloom filter is a multiple of 4, then the jhash2() function is used to compute hashes. The length parameter of this function equals to the number of 32-bit words in input. Compute it in the hot path instead of pre-computing it, as this is translated to one extra shift to divide the length by four vs. one extra memory load of a pre-computed length. Signed-off-by: Anton Protopopov <aspsk@isovalent.com> Link: https://lore.kernel.org/r/20230402114340.3441-1-aspsk@isovalent.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Anton Protopopov
|
5b85575ad4 |
bpf: optimize hashmap lookups when key_size is divisible by 4
The BPF hashmap uses the jhash() hash function. There is an optimized version
of this hash function which may be used if hash size is a multiple of 4. Apply
this optimization to the hashmap in a similar way as it is done in the bloom
filter map.
On practice the optimization is only noticeable for smaller key sizes, which,
however, is sufficient for many applications. An example is listed in the
following table of measurements (a hashmap of 65536 elements was used):
--------------------------------------------------------------------
| key_size | fullness | lookups /sec | lookups (opt) /sec | gain |
--------------------------------------------------------------------
| 4 | 25% | 42.990M | 46.000M | 7.0% |
| 4 | 50% | 37.910M | 39.094M | 3.1% |
| 4 | 75% | 34.486M | 36.124M | 4.7% |
| 4 | 100% | 31.760M | 32.719M | 3.0% |
--------------------------------------------------------------------
| 8 | 25% | 43.855M | 49.626M | 13.2% |
| 8 | 50% | 38.328M | 42.152M | 10.0% |
| 8 | 75% | 34.483M | 38.088M | 10.5% |
| 8 | 100% | 31.306M | 34.686M | 10.8% |
--------------------------------------------------------------------
| 12 | 25% | 38.398M | 43.770M | 14.0% |
| 12 | 50% | 33.336M | 37.712M | 13.1% |
| 12 | 75% | 29.917M | 34.440M | 15.1% |
| 12 | 100% | 27.322M | 30.480M | 11.6% |
--------------------------------------------------------------------
| 16 | 25% | 41.491M | 41.921M | 1.0% |
| 16 | 50% | 36.206M | 36.474M | 0.7% |
| 16 | 75% | 32.529M | 33.027M | 1.5% |
| 16 | 100% | 29.581M | 30.325M | 2.5% |
--------------------------------------------------------------------
| 20 | 25% | 34.240M | 36.787M | 7.4% |
| 20 | 50% | 30.328M | 32.663M | 7.7% |
| 20 | 75% | 27.536M | 29.354M | 6.6% |
| 20 | 100% | 24.847M | 26.505M | 6.7% |
--------------------------------------------------------------------
| 24 | 25% | 36.329M | 40.608M | 11.8% |
| 24 | 50% | 31.444M | 35.059M | 11.5% |
| 24 | 75% | 28.426M | 31.452M | 10.6% |
| 24 | 100% | 26.278M | 28.741M | 9.4% |
--------------------------------------------------------------------
| 28 | 25% | 31.540M | 31.944M | 1.3% |
| 28 | 50% | 27.739M | 28.063M | 1.2% |
| 28 | 75% | 24.993M | 25.814M | 3.3% |
| 28 | 100% | 23.513M | 23.500M | -0.1% |
--------------------------------------------------------------------
| 32 | 25% | 32.116M | 33.953M | 5.7% |
| 32 | 50% | 28.879M | 29.859M | 3.4% |
| 32 | 75% | 26.227M | 26.948M | 2.7% |
| 32 | 100% | 23.829M | 24.613M | 3.3% |
--------------------------------------------------------------------
| 64 | 25% | 22.535M | 22.554M | 0.1% |
| 64 | 50% | 20.471M | 20.675M | 1.0% |
| 64 | 75% | 19.077M | 19.146M | 0.4% |
| 64 | 100% | 17.710M | 18.131M | 2.4% |
--------------------------------------------------------------------
The following script was used to gather the results (SMT & frequency off):
cd tools/testing/selftests/bpf
for key_size in 4 8 12 16 20 24 28 32 64; do
for nr_entries in `seq 16384 16384 65536`; do
fullness=$(printf '%3s' $((nr_entries*100/65536)))
echo -n "key_size=$key_size: $fullness% full: "
sudo ./bench -d2 -a bpf-hashmap-lookup --key_size=$key_size --nr_entries=$nr_entries --max_entries=65536 --nr_loops=2000000 --map_flags=0x40 | grep cpu
done
echo
done
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Link: https://lore.kernel.org/r/20230401200602.3275-1-aspsk@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
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|
David Vernet
|
f85671c6ef |
bpf: Remove now-defunct task kfuncs
In commit
|
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David Vernet
|
d02c48fa11 |
bpf: Make struct task_struct an RCU-safe type
struct task_struct objects are a bit interesting in terms of how their lifetime is protected by refcounts. task structs have two refcount fields: 1. refcount_t usage: Protects the memory backing the task struct. When this refcount drops to 0, the task is immediately freed, without waiting for an RCU grace period to elapse. This is the field that most callers in the kernel currently use to ensure that a task remains valid while it's being referenced, and is what's currently tracked with bpf_task_acquire() and bpf_task_release(). 2. refcount_t rcu_users: A refcount field which, when it drops to 0, schedules an RCU callback that drops a reference held on the 'usage' field above (which is acquired when the task is first created). This field therefore provides a form of RCU protection on the task by ensuring that at least one 'usage' refcount will be held until an RCU grace period has elapsed. The qualifier "a form of" is important here, as a task can remain valid after task->rcu_users has dropped to 0 and the subsequent RCU gp has elapsed. In terms of BPF, we want to use task->rcu_users to protect tasks that function as referenced kptrs, and to allow tasks stored as referenced kptrs in maps to be accessed with RCU protection. Let's first determine whether we can safely use task->rcu_users to protect tasks stored in maps. All of the bpf_task* kfuncs can only be called from tracepoint, struct_ops, or BPF_PROG_TYPE_SCHED_CLS, program types. For tracepoint and struct_ops programs, the struct task_struct passed to a program handler will always be trusted, so it will always be safe to call bpf_task_acquire() with any task passed to a program. Note, however, that we must update bpf_task_acquire() to be KF_RET_NULL, as it is possible that the task has exited by the time the program is invoked, even if the pointer is still currently valid because the main kernel holds a task->usage refcount. For BPF_PROG_TYPE_SCHED_CLS, tasks should never be passed as an argument to the any program handlers, so it should not be relevant. The second question is whether it's safe to use RCU to access a task that was acquired with bpf_task_acquire(), and stored in a map. Because bpf_task_acquire() now uses task->rcu_users, it follows that if the task is present in the map, that it must have had at least one task->rcu_users refcount by the time the current RCU cs was started. Therefore, it's safe to access that task until the end of the current RCU cs. With all that said, this patch makes struct task_struct is an RCU-protected object. In doing so, we also change bpf_task_acquire() to be KF_ACQUIRE | KF_RCU | KF_RET_NULL, and adjust any selftests as necessary. A subsequent patch will remove bpf_task_kptr_get(), and bpf_task_acquire_not_zero() respectively. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230331195733.699708-2-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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David Vernet
|
e4c2acab95 |
bpf: Handle PTR_MAYBE_NULL case in PTR_TO_BTF_ID helper call arg
When validating a helper function argument, we use check_reg_type() to
ensure that the register containing the argument is of the correct type.
When the register's base type is PTR_TO_BTF_ID, there is some
supplemental logic where we do extra checks for various combinations of
PTR_TO_BTF_ID type modifiers. For example, for PTR_TO_BTF_ID,
PTR_TO_BTF_ID | PTR_TRUSTED, and PTR_TO_BTF_ID | MEM_RCU, we call
map_kptr_match_type() for bpf_kptr_xchg() calls, and
btf_struct_ids_match() for other helper calls.
When an unhandled PTR_TO_BTF_ID type modifier combination is passed to
check_reg_type(), the verifier fails with an internal verifier error
message. This can currently be triggered by passing a PTR_MAYBE_NULL
pointer to helper functions (currently just bpf_kptr_xchg()) with an
ARG_PTR_TO_BTF_ID_OR_NULL arg type. For example, by callin
bpf_kptr_xchg(&v->kptr, bpf_cpumask_create()).
Whether or not passing a PTR_MAYBE_NULL arg to an
ARG_PTR_TO_BTF_ID_OR_NULL argument is valid is an interesting question.
In a vacuum, it seems fine. A helper function with an
ARG_PTR_TO_BTF_ID_OR_NULL arg would seem to be implying that it can
handle either a NULL or non-NULL arg, and has logic in place to detect
and gracefully handle each. This is the case for bpf_kptr_xchg(), which
of course simply does an xchg(). On the other hand, bpf_kptr_xchg() also
specifies OBJ_RELEASE, and refcounting semantics for a PTR_MAYBE_NULL
pointer is different than handling it for a NULL _OR_ non-NULL pointer.
For example, with a non-NULL arg, we should always fail if there was not
a nonzero refcount for the value in the register being passed to the
helper. For PTR_MAYBE_NULL on the other hand, it's unclear. If the
pointer is NULL it would be fine, but if it's not NULL, it would be
incorrect to load the program.
The current solution to this is to just fail if PTR_MAYBE_NULL is
passed, and to instead require programs to have a NULL check to
explicitly handle the NULL and non-NULL cases. This seems reasonable.
Not only would it possibly be quite complicated to correctly handle
PTR_MAYBE_NULL refcounting in the verifier, but it's also an arguably
odd programming pattern in general to not explicitly handle the NULL
case anyways. For example, it seems odd to not care about whether a
pointer you're passing to bpf_kptr_xchg() was successfully allocated in
a program such as the following:
private(MASK) static struct bpf_cpumask __kptr * global_mask;
SEC("tp_btf/task_newtask")
int BPF_PROG(example, struct task_struct *task, u64 clone_flags)
{
struct bpf_cpumask *prev;
/* bpf_cpumask_create() returns PTR_MAYBE_NULL */
prev = bpf_kptr_xchg(&global_mask, bpf_cpumask_create());
if (prev)
bpf_cpumask_release(prev);
return 0;
}
This patch therefore updates the verifier to explicitly check for
PTR_MAYBE_NULL in check_reg_type(), and fail gracefully if it's
observed. This isn't really "fixing" anything unsafe or incorrect. We're
just updating the verifier to fail gracefully, and explicitly handle
this pattern rather than unintentionally falling back to an internal
verifier error path. A subsequent patch will update selftests.
Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230330145203.80506-1-void@manifault.com
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Martin KaFai Lau
|
6ae9d5e99e |
bpf: Use bpf_mem_cache_alloc/free for bpf_local_storage
This patch uses bpf_mem_cache_alloc/free for allocating and freeing bpf_local_storage for task and cgroup storage. The changes are similar to the previous patch. A few things that worth to mention for bpf_local_storage: The local_storage is freed when the last selem is deleted. Before deleting a selem from local_storage, it needs to retrieve the local_storage->smap because the bpf_selem_unlink_storage_nolock() may have set it to NULL. Note that local_storage->smap may have already been NULL when the selem created this local_storage has been removed. In this case, call_rcu will be used to free the local_storage. Also, the bpf_ma (true or false) value is needed before calling bpf_local_storage_free(). The bpf_ma can either be obtained from the local_storage->smap (if available) or any of its selem's smap. A new helper check_storage_bpf_ma() is added to obtain bpf_ma for a deleting bpf_local_storage. When bpf_local_storage_alloc getting a reused memory, all fields are either in the correct values or will be initialized. 'cache[]' must already be all NULLs. 'list' must be empty. Others will be initialized. Cc: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20230322215246.1675516-4-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Martin KaFai Lau
|
08a7ce384e |
bpf: Use bpf_mem_cache_alloc/free in bpf_local_storage_elem
This patch uses bpf_mem_alloc for the task and cgroup local storage that the bpf prog can easily get a hold of the storage owner's PTR_TO_BTF_ID. eg. bpf_get_current_task_btf() can be used in some of the kmalloc code path which will cause deadlock/recursion. bpf_mem_cache_alloc is deadlock free and will solve a legit use case in [1]. For sk storage, its batch creation benchmark shows a few percent regression when the sk create/destroy batch size is larger than 32. The sk creation/destruction happens much more often and depends on external traffic. Considering it is hypothetical to be able to cause deadlock with sk storage, it can cross the bridge to use bpf_mem_alloc till a legit (ie. useful) use case comes up. For inode storage, bpf_local_storage_destroy() is called before waiting for a rcu gp and its memory cannot be reused immediately. inode stays with kmalloc/kfree after the rcu [or tasks_trace] gp. A 'bool bpf_ma' argument is added to bpf_local_storage_map_alloc(). Only task and cgroup storage have 'bpf_ma == true' which means to use bpf_mem_cache_alloc/free(). This patch only changes selem to use bpf_mem_alloc for task and cgroup. The next patch will change the local_storage to use bpf_mem_alloc also for task and cgroup. Here is some more details on the changes: * memory allocation: After bpf_mem_cache_alloc(), the SDATA(selem)->data is zero-ed because bpf_mem_cache_alloc() could return a reused selem. It is to keep the existing bpf_map_kzalloc() behavior. Only SDATA(selem)->data is zero-ed. SDATA(selem)->data is the visible part to the bpf prog. No need to use zero_map_value() to do the zeroing because bpf_selem_free(..., reuse_now = true) ensures no bpf prog is using the selem before returning the selem through bpf_mem_cache_free(). For the internal fields of selem, they will be initialized when linking to the new smap and the new local_storage. When 'bpf_ma == false', nothing changes in this patch. It will stay with the bpf_map_kzalloc(). * memory free: The bpf_selem_free() and bpf_selem_free_rcu() are modified to handle the bpf_ma == true case. For the common selem free path where its owner is also being destroyed, the mem is freed in bpf_local_storage_destroy(), the owner (task and cgroup) has gone through a rcu gp. The memory can be reused immediately, so bpf_local_storage_destroy() will call bpf_selem_free(..., reuse_now = true) which will do bpf_mem_cache_free() for immediate reuse consideration. An exception is the delete elem code path. The delete elem code path is called from the helper bpf_*_storage_delete() and the syscall bpf_map_delete_elem(). This path is an unusual case for local storage because the common use case is to have the local storage staying with its owner life time so that the bpf prog and the user space does not have to monitor the owner's destruction. For the delete elem path, the selem cannot be reused immediately because there could be bpf prog using it. It will call bpf_selem_free(..., reuse_now = false) and it will wait for a rcu tasks trace gp before freeing the elem. The rcu callback is changed to do bpf_mem_cache_raw_free() instead of kfree(). When 'bpf_ma == false', it should be the same as before. __bpf_selem_free() is added to do the kfree_rcu and call_tasks_trace_rcu(). A few words on the 'reuse_now == true'. When 'reuse_now == true', it is still racing with bpf_local_storage_map_free which is under rcu protection, so it still needs to wait for a rcu gp instead of kfree(). Otherwise, the selem may be reused by slab for a totally different struct while the bpf_local_storage_map_free() is still using it (as a rcu reader). For the inode case, there may be other rcu readers also. In short, when bpf_ma == false and reuse_now == true => vanilla rcu. [1]: https://lore.kernel.org/bpf/20221118190109.1512674-1-namhyung@kernel.org/ Cc: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20230322215246.1675516-3-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Martin KaFai Lau
|
e65a5c6edb |
bpf: Add a few bpf mem allocator functions
This patch adds a few bpf mem allocator functions which will be used in the bpf_local_storage in a later patch. bpf_mem_cache_alloc_flags(..., gfp_t flags) is added. When the flags == GFP_KERNEL, it will fallback to __alloc(..., GFP_KERNEL). bpf_local_storage knows its running context is sleepable (GFP_KERNEL) and provides a better guarantee on memory allocation. bpf_local_storage has some uncommon cases that its selem cannot be reused immediately. It handles its own rcu_head and goes through a rcu_trace gp and then free it. bpf_mem_cache_raw_free() is added for direct free purpose without leaking the LLIST_NODE_SZ internal knowledge. During free time, the 'struct bpf_mem_alloc *ma' is no longer available. However, the caller should know if it is percpu memory or not and it can call different raw_free functions. bpf_local_storage does not support percpu value, so only the non-percpu 'bpf_mem_cache_raw_free()' is added in this patch. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20230322215246.1675516-2-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
David Vernet
|
6c831c4684 |
bpf: Treat KF_RELEASE kfuncs as KF_TRUSTED_ARGS
KF_RELEASE kfuncs are not currently treated as having KF_TRUSTED_ARGS, even though they have a superset of the requirements of KF_TRUSTED_ARGS. Like KF_TRUSTED_ARGS, KF_RELEASE kfuncs require a 0-offset argument, and don't allow NULL-able arguments. Unlike KF_TRUSTED_ARGS which require _either_ an argument with ref_obj_id > 0, _or_ (ref->type & BPF_REG_TRUSTED_MODIFIERS) (and no unsafe modifiers allowed), KF_RELEASE only allows for ref_obj_id > 0. Because KF_RELEASE today doesn't automatically imply KF_TRUSTED_ARGS, some of these requirements are enforced in different ways that can make the behavior of the verifier feel unpredictable. For example, a KF_RELEASE kfunc with a NULL-able argument will currently fail in the verifier with a message like, "arg#0 is ptr_or_null_ expected ptr_ or socket" rather than "Possibly NULL pointer passed to trusted arg0". Our intention is the same, but the semantics are different due to implemenetation details that kfunc authors and BPF program writers should not need to care about. Let's make the behavior of the verifier more consistent and intuitive by having KF_RELEASE kfuncs imply the presence of KF_TRUSTED_ARGS. Our eventual goal is to have all kfuncs assume KF_TRUSTED_ARGS by default anyways, so this takes us a step in that direction. Note that it does not make sense to assume KF_TRUSTED_ARGS for all KF_ACQUIRE kfuncs. KF_ACQUIRE kfuncs can have looser semantics than KF_RELEASE, with e.g. KF_RCU | KF_RET_NULL. We may want to have KF_ACQUIRE imply KF_TRUSTED_ARGS _unless_ KF_RCU is specified, but that can be left to another patch set, and there are no such subtleties to address for KF_RELEASE. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230325213144.486885-4-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
David Vernet
|
fb2211a57c |
bpf: Remove now-unnecessary NULL checks for KF_RELEASE kfuncs
Now that we're not invoking kfunc destructors when the kptr in a map was NULL, we no longer require NULL checks in many of our KF_RELEASE kfuncs. This patch removes those NULL checks. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230325213144.486885-3-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
David Vernet
|
1431d0b584 |
bpf: Only invoke kptr dtor following non-NULL xchg
When a map value is being freed, we loop over all of the fields of the corresponding BPF object and issue the appropriate cleanup calls corresponding to the field's type. If the field is a referenced kptr, we atomically xchg the value out of the map, and invoke the kptr's destructor on whatever was there before (or bpf_obj_drop() it if it was a local kptr). Currently, we always invoke the destructor (either bpf_obj_drop() or the kptr's registered destructor) on any KPTR_REF-type field in a map, even if there wasn't a value in the map. This means that any function serving as the kptr's KF_RELEASE destructor must always treat the argument as possibly NULL, as the following can and regularly does happen: void *xchgd_field; /* No value was in the map, so xchgd_field is NULL */ xchgd_field = (void *)xchg(unsigned long *field_ptr, 0); field->kptr.dtor(xchgd_field); These are odd semantics to impose on KF_RELEASE kfuncs -- BPF programs are prohibited by the verifier from passing NULL pointers to KF_RELEASE kfuncs, so it doesn't make sense to require this of BPF programs, but not the main kernel destructor path. It's also unnecessary to invoke any cleanup logic for local kptrs. If there is no object there, there's nothing to drop. So as to allow KF_RELEASE kfuncs to fully assume that an argument is non-NULL, this patch updates a KPTR_REF's destructor to only be invoked when a non-NULL value is xchg'd out of the kptr map field. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230325213144.486885-2-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Martin KaFai Lau
|
55fbae0547 |
bpf: Check IS_ERR for the bpf_map_get() return value
This patch fixes a mistake in checking NULL instead of checking IS_ERR for the bpf_map_get() return value. It also fixes the return value in link_update_map() from -EINVAL to PTR_ERR(*_map). Reported-by: syzbot+71ccc0fe37abb458406b@syzkaller.appspotmail.com Fixes: |
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|
Jakub Kicinski
|
dc0a7b5200 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts: drivers/net/ethernet/mellanox/mlx5/core/en_tc.c |
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Kui-Feng Lee
|
aef56f2e91 |
bpf: Update the struct_ops of a bpf_link.
By improving the BPF_LINK_UPDATE command of bpf(), it should allow you to conveniently switch between different struct_ops on a single bpf_link. This would enable smoother transitions from one struct_ops to another. The struct_ops maps passing along with BPF_LINK_UPDATE should have the BPF_F_LINK flag. Signed-off-by: Kui-Feng Lee <kuifeng@meta.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230323032405.3735486-6-kuifeng@meta.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> |
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Kui-Feng Lee
|
68b04864ca |
bpf: Create links for BPF struct_ops maps.
Make bpf_link support struct_ops. Previously, struct_ops were always used alone without any associated links. Upon updating its value, a struct_ops would be activated automatically. Yet other BPF program types required to make a bpf_link with their instances before they could become active. Now, however, you can create an inactive struct_ops, and create a link to activate it later. With bpf_links, struct_ops has a behavior similar to other BPF program types. You can pin/unpin them from their links and the struct_ops will be deactivated when its link is removed while previously need someone to delete the value for it to be deactivated. bpf_links are responsible for registering their associated struct_ops. You can only use a struct_ops that has the BPF_F_LINK flag set to create a bpf_link, while a structs without this flag behaves in the same manner as before and is registered upon updating its value. The BPF_LINK_TYPE_STRUCT_OPS serves a dual purpose. Not only is it used to craft the links for BPF struct_ops programs, but also to create links for BPF struct_ops them-self. Since the links of BPF struct_ops programs are only used to create trampolines internally, they are never seen in other contexts. Thus, they can be reused for struct_ops themself. To maintain a reference to the map supporting this link, we add bpf_struct_ops_link as an additional type. The pointer of the map is RCU and won't be necessary until later in the patchset. Signed-off-by: Kui-Feng Lee <kuifeng@meta.com> Link: https://lore.kernel.org/r/20230323032405.3735486-4-kuifeng@meta.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> |
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Kui-Feng Lee
|
b671c2067a |
bpf: Retire the struct_ops map kvalue->refcnt.
We have replaced kvalue-refcnt with synchronize_rcu() to wait for an RCU grace period. Maintenance of kvalue->refcnt was a complicated task, as we had to simultaneously keep track of two reference counts: one for the reference count of bpf_map. When the kvalue->refcnt reaches zero, we also have to reduce the reference count on bpf_map - yet these steps are not performed in an atomic manner and require us to be vigilant when managing them. By eliminating kvalue->refcnt, we can make our maintenance more straightforward as the refcount of bpf_map is now solely managed! To prevent the trampoline image of a struct_ops from being released while it is still in use, we wait for an RCU grace period. The setsockopt(TCP_CONGESTION, "...") command allows you to change your socket's congestion control algorithm and can result in releasing the old struct_ops implementation. It is fine. However, this function is exposed through bpf_setsockopt(), it may be accessed by BPF programs as well. To ensure that the trampoline image belonging to struct_op can be safely called while its method is in use, the trampoline safeguarde the BPF program with rcu_read_lock(). Doing so prevents any destruction of the associated images before returning from a trampoline and requires us to wait for an RCU grace period. Signed-off-by: Kui-Feng Lee <kuifeng@meta.com> Link: https://lore.kernel.org/r/20230323032405.3735486-2-kuifeng@meta.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> |
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Andrii Nakryiko
|
b63cbc490e |
bpf: remember meta->iter info only for initialized iters
For iter_new() functions iterator state's slot might not be yet
initialized, in which case iter_get_spi() will return -ERANGE. This is
expected and is handled properly. But for iter_next() and iter_destroy()
cases iter slot is supposed to be initialized and correct, so -ERANGE is
not possible.
Move meta->iter.{spi,frameno} initialization into iter_next/iter_destroy
handling branch to make it more explicit that valid information will be
remembered in meta->iter block for subsequent use in process_iter_next_call(),
avoiding confusingly looking -ERANGE assignment for meta->iter.spi.
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230322232502.836171-1-andrii@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
|
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|
Daniel Borkmann
|
7be14c1c90 |
bpf: Fix __reg_bound_offset 64->32 var_off subreg propagation
Xu reports that after commit |
||
|
JP Kobryn
|
d7ba4cc900 |
bpf: return long from bpf_map_ops funcs
This patch changes the return types of bpf_map_ops functions to long, where previously int was returned. Using long allows for bpf programs to maintain the sign bit in the absence of sign extension during situations where inlined bpf helper funcs make calls to the bpf_map_ops funcs and a negative error is returned. The definitions of the helper funcs are generated from comments in the bpf uapi header at `include/uapi/linux/bpf.h`. The return type of these helpers was previously changed from int to long in commit |
||
|
Alexei Starovoitov
|
1057d29945 |
bpf: Teach the verifier to recognize rdonly_mem as not null.
Teach the verifier to recognize PTR_TO_MEM | MEM_RDONLY as not NULL otherwise if (!bpf_ksym_exists(known_kfunc)) doesn't go through dead code elimination. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/20230321203854.3035-3-alexei.starovoitov@gmail.com |
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|
Daniel Borkmann
|
10ec8ca8ec |
bpf: Adjust insufficient default bpf_jit_limit
We've seen recent AWS EKS (Kubernetes) user reports like the following:
After upgrading EKS nodes from v20230203 to v20230217 on our 1.24 EKS
clusters after a few days a number of the nodes have containers stuck
in ContainerCreating state or liveness/readiness probes reporting the
following error:
Readiness probe errored: rpc error: code = Unknown desc = failed to
exec in container: failed to start exec "4a11039f730203ffc003b7[...]":
OCI runtime exec failed: exec failed: unable to start container process:
unable to init seccomp: error loading seccomp filter into kernel:
error loading seccomp filter: errno 524: unknown
However, we had not been seeing this issue on previous AMIs and it only
started to occur on v20230217 (following the upgrade from kernel 5.4 to
5.10) with no other changes to the underlying cluster or workloads.
We tried the suggestions from that issue (sysctl net.core.bpf_jit_limit=452534528)
which helped to immediately allow containers to be created and probes to
execute but after approximately a day the issue returned and the value
returned by cat /proc/vmallocinfo | grep bpf_jit | awk '{s+=$2} END {print s}'
was steadily increasing.
I tested bpf tree to observe bpf_jit_charge_modmem, bpf_jit_uncharge_modmem
their sizes passed in as well as bpf_jit_current under tcpdump BPF filter,
seccomp BPF and native (e)BPF programs, and the behavior all looks sane
and expected, that is nothing "leaking" from an upstream perspective.
The bpf_jit_limit knob was originally added in order to avoid a situation
where unprivileged applications loading BPF programs (e.g. seccomp BPF
policies) consuming all the module memory space via BPF JIT such that loading
of kernel modules would be prevented. The default limit was defined back in
2018 and while good enough back then, we are generally seeing far more BPF
consumers today.
Adjust the limit for the BPF JIT pool from originally 1/4 to now 1/2 of the
module memory space to better reflect today's needs and avoid more users
running into potentially hard to debug issues.
Fixes:
|
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|
Florent Revest
|
da8bdfbd42 |
ftrace: Rename _ftrace_direct_multi APIs to _ftrace_direct APIs
Now that the original _ftrace_direct APIs are gone, the "_multi" suffixes only add confusion. Link: https://lkml.kernel.org/r/20230321140424.345218-5-revest@chromium.org Signed-off-by: Florent Revest <revest@chromium.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Florent Revest
|
59495740f7 |
ftrace: Let unregister_ftrace_direct_multi() call ftrace_free_filter()
A common pattern when using the ftrace_direct_multi API is to unregister the ops and also immediately free its filter. We've noticed it's very easy for users to miss calling ftrace_free_filter(). This adds a "free_filters" argument to unregister_ftrace_direct_multi() to both remind the user they should free filters and also to make their life easier. Link: https://lkml.kernel.org/r/20230321140424.345218-2-revest@chromium.org Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Florent Revest <revest@chromium.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> |
||
|
Alexei Starovoitov
|
58aa2afbb1 |
bpf: Allow ld_imm64 instruction to point to kfunc.
Allow ld_imm64 insn with BPF_PSEUDO_BTF_ID to hold the address of kfunc. The ld_imm64 pointing to a valid kfunc will be seen as non-null PTR_TO_MEM by is_branch_taken() logic of the verifier, while libbpf will resolve address to unknown kfunc as ld_imm64 reg, 0 which will also be recognized by is_branch_taken() and the verifier will proceed dead code elimination. BPF programs can use this logic to detect at load time whether kfunc is present in the kernel with bpf_ksym_exists() macro that is introduced in the next patches. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20230317201920.62030-2-alexei.starovoitov@gmail.com |
||
|
Kamalesh Babulal
|
4cdb91b0de |
cgroup: bpf: use cgroup_lock()/cgroup_unlock() wrappers
Replace mutex_[un]lock() with cgroup_[un]lock() wrappers to stay consistent across cgroup core and other subsystem code, while operating on the cgroup_mutex. Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org> |
||
|
Viktor Malik
|
bd5314f8dd |
kallsyms, bpf: Move find_kallsyms_symbol_value out of internal header
Moving find_kallsyms_symbol_value from kernel/module/internal.h to
include/linux/module.h. The reason is that internal.h is not prepared to
be included when CONFIG_MODULES=n. find_kallsyms_symbol_value is used by
kernel/bpf/verifier.c and including internal.h from it (without modules)
leads into a compilation error:
In file included from ../include/linux/container_of.h:5,
from ../include/linux/list.h:5,
from ../include/linux/timer.h:5,
from ../include/linux/workqueue.h:9,
from ../include/linux/bpf.h:10,
from ../include/linux/bpf-cgroup.h:5,
from ../kernel/bpf/verifier.c:7:
../kernel/bpf/../module/internal.h: In function 'mod_find':
../include/linux/container_of.h:20:54: error: invalid use of undefined type 'struct module'
20 | static_assert(__same_type(*(ptr), ((type *)0)->member) || \
| ^~
[...]
This patch fixes the above error.
Fixes:
|
||
|
Luis Gerhorst
|
082cdc69a4 |
bpf: Remove misleading spec_v1 check on var-offset stack read
For every BPF_ADD/SUB involving a pointer, adjust_ptr_min_max_vals() ensures that the resulting pointer has a constant offset if bypass_spec_v1 is false. This is ensured by calling sanitize_check_bounds() which in turn calls check_stack_access_for_ptr_arithmetic(). There, -EACCESS is returned if the register's offset is not constant, thereby rejecting the program. In summary, an unprivileged user must never be able to create stack pointers with a variable offset. That is also the case, because a respective check in check_stack_write() is missing. If they were able to create a variable-offset pointer, users could still use it in a stack-write operation to trigger unsafe speculative behavior [1]. Because unprivileged users must already be prevented from creating variable-offset stack pointers, viable options are to either remove this check (replacing it with a clarifying comment), or to turn it into a "verifier BUG"-message, also adding a similar check in check_stack_write() (for consistency, as a second-level defense). This patch implements the first option to reduce verifier bloat. This check was introduced by commit |
||
|
David Vernet
|
1b403ce77d |
bpf: Remove bpf_cpumask_kptr_get() kfunc
Now that struct bpf_cpumask is RCU safe, there's no need for this kfunc.
Rather than doing the following:
private(MASK) static struct bpf_cpumask __kptr *global;
int BPF_PROG(prog, s32 cpu, ...)
{
struct bpf_cpumask *cpumask;
bpf_rcu_read_lock();
cpumask = bpf_cpumask_kptr_get(&global);
if (!cpumask) {
bpf_rcu_read_unlock();
return -1;
}
bpf_cpumask_setall(cpumask);
...
bpf_cpumask_release(cpumask);
bpf_rcu_read_unlock();
}
Programs can instead simply do (assume same global cpumask):
int BPF_PROG(prog, ...)
{
struct bpf_cpumask *cpumask;
bpf_rcu_read_lock();
cpumask = global;
if (!cpumask) {
bpf_rcu_read_unlock();
return -1;
}
bpf_cpumask_setall(cpumask);
...
bpf_rcu_read_unlock();
}
In other words, no extra atomic acquire / release, and less boilerplate
code.
This patch removes both the kfunc, as well as its selftests and
documentation.
Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230316054028.88924-5-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
David Vernet
|
63d2d83d21 |
bpf: Mark struct bpf_cpumask as rcu protected
struct bpf_cpumask is a BPF-wrapper around the struct cpumask type which can be instantiated by a BPF program, and then queried as a cpumask in similar fashion to normal kernel code. The previous patch in this series makes the type fully RCU safe, so the type can be included in the rcu_protected_type BTF ID list. A subsequent patch will remove bpf_cpumask_kptr_get(), as it's no longer useful now that we can just treat the type as RCU safe by default and do our own if check. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230316054028.88924-3-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
David Vernet
|
77473d1a96 |
bpf: Free struct bpf_cpumask in call_rcu handler
The struct bpf_cpumask type uses the bpf_mem_cache_{alloc,free}() APIs
to allocate and free its cpumasks. The bpf_mem allocator may currently
immediately reuse some memory when its freed, without waiting for an RCU
read cycle to elapse. We want to be able to treat struct bpf_cpumask
objects as completely RCU safe.
This is necessary for two reasons:
1. bpf_cpumask_kptr_get() currently does an RCU-protected
refcnt_inc_not_zero(). This of course assumes that the underlying
memory is not reused, and is therefore unsafe in its current form.
2. We want to be able to get rid of bpf_cpumask_kptr_get() entirely, and
intead use the superior kptr RCU semantics now afforded by the
verifier.
This patch fixes (1), and enables (2), by making struct bpf_cpumask RCU
safe. A subsequent patch will update the verifier to allow struct
bpf_cpumask * pointers to be passed to KF_RCU kfuncs, and then a latter
patch will remove bpf_cpumask_kptr_get().
Fixes:
|
||
|
Viktor Malik
|
31bf1dbccf |
bpf: Fix attaching fentry/fexit/fmod_ret/lsm to modules
This resolves two problems with attachment of fentry/fexit/fmod_ret/lsm to functions located in modules: 1. The verifier tries to find the address to attach to in kallsyms. This is always done by searching the entire kallsyms, not respecting the module in which the function is located. Such approach causes an incorrect attachment address to be computed if the function to attach to is shadowed by a function of the same name located earlier in kallsyms. 2. If the address to attach to is located in a module, the module reference is only acquired in register_fentry. If the module is unloaded between the place where the address is found (bpf_check_attach_target in the verifier) and register_fentry, it is possible that another module is loaded to the same address which may lead to potential errors. Since the attachment must contain the BTF of the program to attach to, we extract the module from it and search for the function address in the correct module (resolving problem no. 1). Then, the module reference is taken directly in bpf_check_attach_target and stored in the bpf program (in bpf_prog_aux). The reference is only released when the program is unloaded (resolving problem no. 2). Signed-off-by: Viktor Malik <vmalik@redhat.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/3f6a9d8ae850532b5ef864ef16327b0f7a669063.1678432753.git.vmalik@redhat.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Alexei Starovoitov
|
3e30be4288 |
bpf: Allow helpers access trusted PTR_TO_BTF_ID.
The verifier rejects the code: bpf_strncmp(task->comm, 16, "my_task"); with the message: 16: (85) call bpf_strncmp#182 R1 type=trusted_ptr_ expected=fp, pkt, pkt_meta, map_key, map_value, mem, ringbuf_mem, buf Teach the verifier that such access pattern is safe. Do not allow untrusted and legacy ptr_to_btf_id to be passed into helpers. Reported-by: David Vernet <void@manifault.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230313235845.61029-3-alexei.starovoitov@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> |
||
|
Alexei Starovoitov
|
c9267aa8b7 |
bpf: Fix bpf_strncmp proto.
bpf_strncmp() doesn't write into its first argument. Make sure that the verifier knows about it. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230313235845.61029-2-alexei.starovoitov@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> |
||
|
Dave Marchevsky
|
9e36a204bd |
bpf: Disable migration when freeing stashed local kptr using obj drop
When a local kptr is stashed in a map and freed when the map goes away,
currently an error like the below appears:
[ 39.195695] BUG: using smp_processor_id() in preemptible [00000000] code: kworker/u32:15/2875
[ 39.196549] caller is bpf_mem_free+0x56/0xc0
[ 39.196958] CPU: 15 PID: 2875 Comm: kworker/u32:15 Tainted: G O 6.2.0-13016-g22df776a9a86 #4477
[ 39.197897] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
[ 39.198949] Workqueue: events_unbound bpf_map_free_deferred
[ 39.199470] Call Trace:
[ 39.199703] <TASK>
[ 39.199911] dump_stack_lvl+0x60/0x70
[ 39.200267] check_preemption_disabled+0xbf/0xe0
[ 39.200704] bpf_mem_free+0x56/0xc0
[ 39.201032] ? bpf_obj_new_impl+0xa0/0xa0
[ 39.201430] bpf_obj_free_fields+0x1cd/0x200
[ 39.201838] array_map_free+0xad/0x220
[ 39.202193] ? finish_task_switch+0xe5/0x3c0
[ 39.202614] bpf_map_free_deferred+0xea/0x210
[ 39.203006] ? lockdep_hardirqs_on_prepare+0xe/0x220
[ 39.203460] process_one_work+0x64f/0xbe0
[ 39.203822] ? pwq_dec_nr_in_flight+0x110/0x110
[ 39.204264] ? do_raw_spin_lock+0x107/0x1c0
[ 39.204662] ? lockdep_hardirqs_on_prepare+0xe/0x220
[ 39.205107] worker_thread+0x74/0x7a0
[ 39.205451] ? process_one_work+0xbe0/0xbe0
[ 39.205818] kthread+0x171/0x1a0
[ 39.206111] ? kthread_complete_and_exit+0x20/0x20
[ 39.206552] ret_from_fork+0x1f/0x30
[ 39.206886] </TASK>
This happens because the call to __bpf_obj_drop_impl I added in the patch
adding support for stashing local kptrs doesn't disable migration. Prior
to that patch, __bpf_obj_drop_impl logic only ran when called by a BPF
progarm, whereas now it can be called from map free path, so it's
necessary to explicitly disable migration.
Also, refactor a bit to just call __bpf_obj_drop_impl directly instead
of bothering w/ dtor union and setting pointer-to-obj_drop.
Fixes:
|
||
|
Alexei Starovoitov
|
a33a6eaa19 |
Merge branch 'bpf: Allow reads from uninit stack'
Merge commit
|
||
|
Andrii Nakryiko
|
34f0677e7a |
bpf: fix precision propagation verbose logging
Fix wrong order of frame index vs register/slot index in precision
propagation verbose (level 2) output. It's wrong and very confusing as is.
Fixes:
|
||
|
Dave Marchevsky
|
738c96d5e2 |
bpf: Allow local kptrs to be exchanged via bpf_kptr_xchg
The previous patch added necessary plumbing for verifier and runtime to know what to do with non-kernel PTR_TO_BTF_IDs in map values, but didn't provide any way to get such local kptrs into a map value. This patch modifies verifier handling of bpf_kptr_xchg to allow MEM_ALLOC kptr types. check_reg_type is modified accept MEM_ALLOC-flagged input to bpf_kptr_xchg despite such types not being in btf_ptr_types. This could have been done with a MAYBE_MEM_ALLOC equivalent to MAYBE_NULL, but bpf_kptr_xchg is the only helper that I can forsee using MAYBE_MEM_ALLOC, so keep it special-cased for now. The verifier tags bpf_kptr_xchg retval MEM_ALLOC if and only if the BTF associated with the retval is not kernel BTF. Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/r/20230310230743.2320707-3-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Dave Marchevsky
|
c8e1875409 |
bpf: Support __kptr to local kptrs
If a PTR_TO_BTF_ID type comes from program BTF - not vmlinux or module
BTF - it must have been allocated by bpf_obj_new and therefore must be
free'd with bpf_obj_drop. Such a PTR_TO_BTF_ID is considered a "local
kptr" and is tagged with MEM_ALLOC type tag by bpf_obj_new.
This patch adds support for treating __kptr-tagged pointers to "local
kptrs" as having an implicit bpf_obj_drop destructor for referenced kptr
acquire / release semantics. Consider the following example:
struct node_data {
long key;
long data;
struct bpf_rb_node node;
};
struct map_value {
struct node_data __kptr *node;
};
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__type(key, int);
__type(value, struct map_value);
__uint(max_entries, 1);
} some_nodes SEC(".maps");
If struct node_data had a matching definition in kernel BTF, the verifier would
expect a destructor for the type to be registered. Since struct node_data does
not match any type in kernel BTF, the verifier knows that there is no kfunc
that provides a PTR_TO_BTF_ID to this type, and that such a PTR_TO_BTF_ID can
only come from bpf_obj_new. So instead of searching for a registered dtor,
a bpf_obj_drop dtor can be assumed.
This allows the runtime to properly destruct such kptrs in
bpf_obj_free_fields, which enables maps to clean up map_vals w/ such
kptrs when going away.
Implementation notes:
* "kernel_btf" variable is renamed to "kptr_btf" in btf_parse_kptr.
Before this patch, the variable would only ever point to vmlinux or
module BTFs, but now it can point to some program BTF for local kptr
type. It's later used to populate the (btf, btf_id) pair in kptr btf
field.
* It's necessary to btf_get the program BTF when populating btf_field
for local kptr. btf_record_free later does a btf_put.
* Behavior for non-local referenced kptrs is not modified, as
bpf_find_btf_id helper only searches vmlinux and module BTFs for
matching BTF type. If such a type is found, btf_field_kptr's btf will
pass btf_is_kernel check, and the associated release function is
some one-argument dtor. If btf_is_kernel check fails, associated
release function is two-arg bpf_obj_drop_impl. Before this patch
only btf_field_kptr's w/ kernel or module BTFs were created.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230310230743.2320707-2-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Dave Marchevsky
|
74843b57ec |
bpf: Change btf_record_find enum parameter to field_mask
btf_record_find's 3rd parameter can be multiple enum btf_field_type's masked together. The function is called with BPF_KPTR in two places in verifier.c, so it works with masked values already. Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/r/20230309180111.1618459-4-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Dave Marchevsky
|
a4aa38897b |
bpf: btf: Remove unused btf_field_info_type enum
This enum was added and used in commit |
||
|
Dave Marchevsky
|
b32a5dae44 |
bpf: verifier: Rename kernel_type_name helper to btf_type_name
kernel_type_name was introduced in commit |
||
|
Martin KaFai Lau
|
7e30a8477b |
bpf: Add bpf_local_storage_free()
This patch refactors local_storage freeing logic into bpf_local_storage_free(). It is a preparation work for a later patch that uses bpf_mem_cache_alloc/free. The other kfree(local_storage) cases are also changed to bpf_local_storage_free(..., reuse_now = true). Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20230308065936.1550103-12-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Martin KaFai Lau
|
1288aaa278 |
bpf: Add bpf_local_storage_rcu callback
The existing bpf_local_storage_free_rcu is renamed to bpf_local_storage_free_trace_rcu. A new bpf_local_storage_rcu callback is added to do the kfree instead of using kfree_rcu. It is a preparation work for a later patch using bpf_mem_cache_alloc/free. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20230308065936.1550103-11-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Martin KaFai Lau
|
c0d63f3091 |
bpf: Add bpf_selem_free()
This patch refactors the selem freeing logic into bpf_selem_free(). It is a preparation work for a later patch using bpf_mem_cache_alloc/free. The other kfree(selem) cases are also changed to bpf_selem_free(..., reuse_now = true). Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20230308065936.1550103-10-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Martin KaFai Lau
|
f8ccf30c17 |
bpf: Add bpf_selem_free_rcu callback
Add bpf_selem_free_rcu() callback to do the kfree() instead of using kfree_rcu. It is a preparation work for using bpf_mem_cache_alloc/free in a later patch. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20230308065936.1550103-9-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Martin KaFai Lau
|
c609981342 |
bpf: Remove bpf_selem_free_fields*_rcu
This patch removes the bpf_selem_free_fields*_rcu. The bpf_obj_free_fields() can be done before the call_rcu_trasks_trace() and kfree_rcu(). It is needed when a later patch uses bpf_mem_cache_alloc/free. In bpf hashtab, bpf_obj_free_fields() is also called before calling bpf_mem_cache_free. The discussion can be found in https://lore.kernel.org/bpf/f67021ee-21d9-bfae-6134-4ca542fab843@linux.dev/ Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20230308065936.1550103-8-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Martin KaFai Lau
|
a47eabf216 |
bpf: Repurpose use_trace_rcu to reuse_now in bpf_local_storage
This patch re-purpose the use_trace_rcu to mean if the freed memory can be reused immediately or not. The use_trace_rcu is renamed to reuse_now. Other than the boolean test is reversed, it should be a no-op. The following explains the reason for the rename and how it will be used in a later patch. In a later patch, bpf_mem_cache_alloc/free will be used in the bpf_local_storage. The bpf mem allocator will reuse the freed memory immediately. Some of the free paths in bpf_local_storage does not support memory to be reused immediately. These paths are the "delete" elem cases from the bpf_*_storage_delete() helper and the map_delete_elem() syscall. Note that "delete" elem before the owner's (sk/task/cgrp/inode) lifetime ended is not the common usage for the local storage. The common free path, bpf_local_storage_destroy(), can reuse the memory immediately. This common path means the storage stays with its owner until the owner is destroyed. The above mentioned "delete" elem paths that cannot reuse immediately always has the 'use_trace_rcu == true'. The cases that is safe for immediate reuse always have 'use_trace_rcu == false'. Instead of adding another arg in a later patch, this patch re-purpose this arg to reuse_now and have the test logic reversed. In a later patch, 'reuse_now == true' will free to the bpf_mem_cache_free() where the memory can be reused immediately. 'reuse_now == false' will go through the call_rcu_tasks_trace(). Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20230308065936.1550103-7-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Martin KaFai Lau
|
fc6652aab6 |
bpf: Remember smap in bpf_local_storage
This patch remembers which smap triggers the allocation of a 'struct bpf_local_storage' object. The local_storage is allocated during the very first selem added to the owner. The smap pointer is needed when using the bpf_mem_cache_free in a later patch because it needs to free to the correct smap's bpf_mem_alloc object. When a selem is being removed, it needs to check if it is the selem that triggers the creation of the local_storage. If it is, the local_storage->smap pointer will be reset to NULL. This NULL reset is done under the local_storage->lock in bpf_selem_unlink_storage_nolock() when a selem is being removed. Also note that the local_storage may not go away even local_storage->smap is NULL because there may be other selem still stored in the local_storage. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20230308065936.1550103-6-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Martin KaFai Lau
|
121f31f3e0 |
bpf: Remove the preceding __ from __bpf_selem_unlink_storage
__bpf_selem_unlink_storage is taking the spin lock and there is no name collision also. Having the preceding '__' is confusing when reviewing the later patch. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20230308065936.1550103-5-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Martin KaFai Lau
|
62827d612a |
bpf: Remove __bpf_local_storage_map_alloc
bpf_local_storage_map_alloc() is the only caller of __bpf_local_storage_map_alloc(). The remaining logic in bpf_local_storage_map_alloc() is only a one liner setting the smap->cache_idx. Remove __bpf_local_storage_map_alloc() to simplify code. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20230308065936.1550103-4-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Martin KaFai Lau
|
2ffcb6fc50 |
bpf: Refactor codes into bpf_local_storage_destroy
This patch first renames bpf_local_storage_unlink_nolock to bpf_local_storage_destroy(). It better reflects that it is only used when the storage's owner (sk/task/cgrp/inode) is being kfree(). All bpf_local_storage_destroy's caller is taking the spin lock and then free the storage. This patch also moves these two steps into the bpf_local_storage_destroy. This is a preparation work for a later patch that uses bpf_mem_cache_alloc/free in the bpf_local_storage. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20230308065936.1550103-3-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Martin KaFai Lau
|
4cbd23cc92 |
bpf: Move a few bpf_local_storage functions to static scope
This patch moves the bpf_local_storage_free_rcu() and bpf_selem_unlink_map() to static because they are not used outside of bpf_local_storage.c. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20230308065936.1550103-2-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
52c2b005a3 |
bpf: take into account liveness when propagating precision
When doing state comparison, if old state has register that is not
marked as REG_LIVE_READ, then we just skip comparison, regardless what's
the state of corresponing register in current state. This is because not
REG_LIVE_READ register is irrelevant for further program execution and
correctness. All good here.
But when we get to precision propagation, after two states were declared
equivalent, we don't take into account old register's liveness, and thus
attempt to propagate precision for register in current state even if
that register in old state was not REG_LIVE_READ anymore. This is bad,
because register in current state could be anything at all and this
could cause -EFAULT due to internal logic bugs.
Fix by taking into account REG_LIVE_READ liveness mark to keep the logic
in state comparison in sync with precision propagation.
Fixes:
|
||
|
Andrii Nakryiko
|
4b5ce570db |
bpf: ensure state checkpointing at iter_next() call sites
State equivalence check and checkpointing performed in is_state_visited() employs certain heuristics to try to save memory by avoiding state checkpoints if not enough jumps and instructions happened since last checkpoint. This leads to unpredictability of whether a particular instruction will be checkpointed and how regularly. While normally this is not causing much problems (except inconveniences for predictable verifier tests, which we overcome with BPF_F_TEST_STATE_FREQ flag), turns out it's not the case for open-coded iterators. Checking and saving state checkpoints at iter_next() call is crucial for fast convergence of open-coded iterator loop logic, so we need to force it. If we don't do that, is_state_visited() might skip saving a checkpoint, causing unnecessarily long sequence of not checkpointed instructions and jumps, leading to exhaustion of jump history buffer, and potentially other undesired outcomes. It is expected that with correct open-coded iterators convergence will happen quickly, so we don't run a risk of exhausting memory. This patch adds, in addition to prune and jump instruction marks, also a "forced checkpoint" mark, and makes sure that any iter_next() call instruction is marked as such. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230310060149.625887-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Jakub Kicinski
|
d0ddf5065f |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Documentation/bpf/bpf_devel_QA.rst |
||
|
Andrii Nakryiko
|
6018e1f407 |
bpf: implement numbers iterator
Implement the first open-coded iterator type over a range of integers.
It's public API consists of:
- bpf_iter_num_new() constructor, which accepts [start, end) range
(that is, start is inclusive, end is exclusive).
- bpf_iter_num_next() which will keep returning read-only pointer to int
until the range is exhausted, at which point NULL will be returned.
If bpf_iter_num_next() is kept calling after this, NULL will be
persistently returned.
- bpf_iter_num_destroy() destructor, which needs to be called at some
point to clean up iterator state. BPF verifier enforces that iterator
destructor is called at some point before BPF program exits.
Note that `start = end = X` is a valid combination to setup an empty
iterator. bpf_iter_num_new() will return 0 (success) for any such
combination.
If bpf_iter_num_new() detects invalid combination of input arguments, it
returns error, resets iterator state to, effectively, empty iterator, so
any subsequent call to bpf_iter_num_next() will keep returning NULL.
BPF verifier has no knowledge that returned integers are in the
[start, end) value range, as both `start` and `end` are not statically
known and enforced: they are runtime values.
While the implementation is pretty trivial, some care needs to be taken
to avoid overflows and underflows. Subsequent selftests will validate
correctness of [start, end) semantics, especially around extremes
(INT_MIN and INT_MAX).
Similarly to bpf_loop(), we enforce that no more than BPF_MAX_LOOPS can
be specified.
bpf_iter_num_{new,next,destroy}() is a logical evolution from bounded
BPF loops and bpf_loop() helper and is the basis for implementing
ergonomic BPF loops with no statically known or verified bounds.
Subsequent patches implement bpf_for() macro, demonstrating how this can
be wrapped into something that works and feels like a normal for() loop
in C language.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230308184121.1165081-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Andrii Nakryiko
|
06accc8779 |
bpf: add support for open-coded iterator loops
Teach verifier about the concept of the open-coded (or inline) iterators.
This patch adds generic iterator loop verification logic, new STACK_ITER
stack slot type to contain iterator state, and necessary kfunc plumbing
for iterator's constructor, destructor and next methods. Next patch
implements first specific iterator (numbers iterator for implementing
for() loop logic). Such split allows to have more focused commits for
verifier logic and separate commit that we could point later to
demonstrating what does it take to add a new kind of iterator.
Each kind of iterator has its own associated struct bpf_iter_<type>,
where <type> denotes a specific type of iterator. struct bpf_iter_<type>
state is supposed to live on BPF program stack, so there will be no way
to change its size later on without breaking backwards compatibility, so
choose wisely! But given this struct is specific to a given <type> of
iterator, this allows a lot of flexibility: simple iterators could be
fine with just one stack slot (8 bytes), like numbers iterator in the
next patch, while some other more complicated iterators might need way
more to keep their iterator state. Either way, such design allows to
avoid runtime memory allocations, which otherwise would be necessary if
we fixed on-the-stack size and it turned out to be too small for a given
iterator implementation.
The way BPF verifier logic is implemented, there are no artificial
restrictions on a number of active iterators, it should work correctly
using multiple active iterators at the same time. This also means you
can have multiple nested iteration loops. struct bpf_iter_<type>
reference can be safely passed to subprograms as well.
General flow is easiest to demonstrate with a simple example using
number iterator implemented in next patch. Here's the simplest possible
loop:
struct bpf_iter_num it;
int *v;
bpf_iter_num_new(&it, 2, 5);
while ((v = bpf_iter_num_next(&it))) {
bpf_printk("X = %d", *v);
}
bpf_iter_num_destroy(&it);
Above snippet should output "X = 2", "X = 3", "X = 4". Note that 5 is
exclusive and is not returned. This matches similar APIs (e.g., slices
in Go or Rust) that implement a range of elements, where end index is
non-inclusive.
In the above example, we see a trio of function:
- constructor, bpf_iter_num_new(), which initializes iterator state
(struct bpf_iter_num it) on the stack. If any of the input arguments
are invalid, constructor should make sure to still initialize it such
that subsequent bpf_iter_num_next() calls will return NULL. I.e., on
error, return error and construct empty iterator.
- next method, bpf_iter_num_next(), which accepts pointer to iterator
state and produces an element. Next method should always return
a pointer. The contract between BPF verifier is that next method will
always eventually return NULL when elements are exhausted. Once NULL is
returned, subsequent next calls should keep returning NULL. In the
case of numbers iterator, bpf_iter_num_next() returns a pointer to an int
(storage for this integer is inside the iterator state itself),
which can be dereferenced after corresponding NULL check.
- once done with the iterator, it's mandated that user cleans up its
state with the call to destructor, bpf_iter_num_destroy() in this
case. Destructor frees up any resources and marks stack space used by
struct bpf_iter_num as usable for something else.
Any other iterator implementation will have to implement at least these
three methods. It is enforced that for any given type of iterator only
applicable constructor/destructor/next are callable. I.e., verifier
ensures you can't pass number iterator state into, say, cgroup
iterator's next method.
It is important to keep the naming pattern consistent to be able to
create generic macros to help with BPF iter usability. E.g., one
of the follow up patches adds generic bpf_for_each() macro to bpf_misc.h
in selftests, which allows to utilize iterator "trio" nicely without
having to code the above somewhat tedious loop explicitly every time.
This is enforced at kfunc registration point by one of the previous
patches in this series.
At the implementation level, iterator state tracking for verification
purposes is very similar to dynptr. We add STACK_ITER stack slot type,
reserve necessary number of slots, depending on
sizeof(struct bpf_iter_<type>), and keep track of necessary extra state
in the "main" slot, which is marked with non-zero ref_obj_id. Other
slots are also marked as STACK_ITER, but have zero ref_obj_id. This is
simpler than having a separate "is_first_slot" flag.
Another big distinction is that STACK_ITER is *always refcounted*, which
simplifies implementation without sacrificing usability. So no need for
extra "iter_id", no need to anticipate reuse of STACK_ITER slots for new
constructors, etc. Keeping it simple here.
As far as the verification logic goes, there are two extensive comments:
in process_iter_next_call() and iter_active_depths_differ() explaining
some important and sometimes subtle aspects. Please refer to them for
details.
But from 10,000-foot point of view, next methods are the points of
forking a verification state, which are conceptually similar to what
verifier is doing when validating conditional jump. We branch out at
a `call bpf_iter_<type>_next` instruction and simulate two outcomes:
NULL (iteration is done) and non-NULL (new element is returned). NULL is
simulated first and is supposed to reach exit without looping. After
that non-NULL case is validated and it either reaches exit (for trivial
examples with no real loop), or reaches another `call bpf_iter_<type>_next`
instruction with the state equivalent to already (partially) validated
one. State equivalency at that point means we technically are going to
be looping forever without "breaking out" out of established "state
envelope" (i.e., subsequent iterations don't add any new knowledge or
constraints to the verifier state, so running 1, 2, 10, or a million of
them doesn't matter). But taking into account the contract stating that
iterator next method *has to* return NULL eventually, we can conclude
that loop body is safe and will eventually terminate. Given we validated
logic outside of the loop (NULL case), and concluded that loop body is
safe (though potentially looping many times), verifier can claim safety
of the overall program logic.
The rest of the patch is necessary plumbing for state tracking, marking,
validation, and necessary further kfunc plumbing to allow implementing
iterator constructor, destructor, and next methods.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230308184121.1165081-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Andrii Nakryiko
|
215bf4962f |
bpf: add iterator kfuncs registration and validation logic
Add ability to register kfuncs that implement BPF open-coded iterator
contract and enforce naming and function proto convention. Enforcement
happens at the time of kfunc registration and significantly simplifies
the rest of iterators logic in the verifier.
More details follow in subsequent patches, but we enforce the following
conditions.
All kfuncs (constructor, next, destructor) have to be named consistenly
as bpf_iter_<type>_{new,next,destroy}(), respectively. <type> represents
iterator type, and iterator state should be represented as a matching
`struct bpf_iter_<type>` state type. Also, all iter kfuncs should have
a pointer to this `struct bpf_iter_<type>` as the very first argument.
Additionally:
- Constructor, i.e., bpf_iter_<type>_new(), can have arbitrary extra
number of arguments. Return type is not enforced either.
- Next method, i.e., bpf_iter_<type>_next(), has to return a pointer
type and should have exactly one argument: `struct bpf_iter_<type> *`
(const/volatile/restrict and typedefs are ignored).
- Destructor, i.e., bpf_iter_<type>_destroy(), should return void and
should have exactly one argument, similar to the next method.
- struct bpf_iter_<type> size is enforced to be positive and
a multiple of 8 bytes (to fit stack slots correctly).
Such strictness and consistency allows to build generic helpers
abstracting important, but boilerplate, details to be able to use
open-coded iterators effectively and ergonomically (see bpf_for_each()
in subsequent patches). It also simplifies the verifier logic in some
places. At the same time, this doesn't hurt generality of possible
iterator implementations. Win-win.
Constructor kfunc is marked with a new KF_ITER_NEW flags, next method is
marked with KF_ITER_NEXT (and should also have KF_RET_NULL, of course),
while destructor kfunc is marked as KF_ITER_DESTROY.
Additionally, we add a trivial kfunc name validation: it should be
a valid non-NULL and non-empty string.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230308184121.1165081-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Andrii Nakryiko
|
07236eab7a |
bpf: factor out fetching basic kfunc metadata
Factor out logic to fetch basic kfunc metadata based on struct bpf_insn. This is not exactly short or trivial code to just copy/paste and this information is sometimes necessary in other parts of the verifier logic. Subsequent patches will rely on this to determine if an instruction is a kfunc call to iterator next method. No functional changes intended, including that verbose() warning behavior when kfunc is not allowed for a particular program type. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230308184121.1165081-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Yafang Shao
|
6b4a6ea2c6 |
bpf: enforce all maps having memory usage callback
We have implemented memory usage callback for all maps, and we enforce any newly added map having a callback as well. We check this callback at map creation time. If it doesn't have the callback, we will return EINVAL. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Link: https://lore.kernel.org/r/20230305124615.12358-19-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Yafang Shao
|
9629363cd0 |
bpf: offload map memory usage
A new helper is introduced to calculate offload map memory usage. But currently the memory dynamically allocated in netdev dev_ops, like nsim_map_update_elem, is not counted. Let's just put it aside now. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Link: https://lore.kernel.org/r/20230305124615.12358-18-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Yafang Shao
|
7490b7f1c0 |
bpf, net: bpf_local_storage memory usage
A new helper is introduced into bpf_local_storage map to calculate the memory usage. This helper is also used by other maps like bpf_cgrp_storage, bpf_inode_storage, bpf_task_storage and etc. Note that currently the dynamically allocated storage elements are not counted in the usage, since it will take extra runtime overhead in the elements update or delete path. So let's put it aside now, and implement it in the future when someone really need it. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Link: https://lore.kernel.org/r/20230305124615.12358-15-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Yafang Shao
|
2f536977d6 |
bpf: local_storage memory usage
A new helper is introduced to calculate local_storage map memory usage. Currently the dynamically allocated elements are not counted, since it will take runtime overhead in the element update or delete path. So let's put it aside currently, and implement it in the future if the user really needs it. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Link: https://lore.kernel.org/r/20230305124615.12358-14-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Yafang Shao
|
f062226d8d |
bpf: bpf_struct_ops memory usage
A new helper is introduced to calculate bpf_struct_ops memory usage.
The result as follows,
- before
1: struct_ops name count_map flags 0x0
key 4B value 256B max_entries 1 memlock 4096B
btf_id 73
- after
1: struct_ops name count_map flags 0x0
key 4B value 256B max_entries 1 memlock 5016B
btf_id 73
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-13-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Yafang Shao
|
c6e66b42a3 |
bpf: queue_stack_maps memory usage
A new helper is introduced to calculate queue_stack_maps memory usage.
The result as follows,
- before
20: queue name count_map flags 0x0
key 0B value 4B max_entries 65536 memlock 266240B
21: stack name count_map flags 0x0
key 0B value 4B max_entries 65536 memlock 266240B
- after
20: queue name count_map flags 0x0
key 0B value 4B max_entries 65536 memlock 524288B
21: stack name count_map flags 0x0
key 0B value 4B max_entries 65536 memlock 524288B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-12-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Yafang Shao
|
fa5e83df17 |
bpf: devmap memory usage
A new helper is introduced to calculate the memory usage of devmap and
devmap_hash. The number of dynamically allocated elements are recored
for devmap_hash already, but not for devmap. To track the memory size of
dynamically allocated elements, this patch also count the numbers for
devmap.
The result as follows,
- before
40: devmap name count_map flags 0x80
key 4B value 4B max_entries 65536 memlock 524288B
41: devmap_hash name count_map flags 0x80
key 4B value 4B max_entries 65536 memlock 524288B
- after
40: devmap name count_map flags 0x80 <<<< no elements
key 4B value 4B max_entries 65536 memlock 524608B
41: devmap_hash name count_map flags 0x80 <<<< no elements
key 4B value 4B max_entries 65536 memlock 524608B
Note that the number of buckets is same with max_entries for devmap_hash
in this case.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-11-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Yafang Shao
|
835f1fca95 |
bpf: cpumap memory usage
A new helper is introduced to calculate cpumap memory usage. The size of
cpu_entries can be dynamically changed when we update or delete a cpumap
element, but this patch doesn't include the memory size of cpu_entry
yet. We can dynamically calculate the memory usage when we alloc or free
a cpu_entry, but it will take extra runtime overhead, so let just put it
aside currently. Note that the size of different cpu_entry may be
different as well.
The result as follows,
- before
48: cpumap name count_map flags 0x4
key 4B value 4B max_entries 64 memlock 4096B
- after
48: cpumap name count_map flags 0x4
key 4B value 4B max_entries 64 memlock 832B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-10-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Yafang Shao
|
71a49abe73 |
bpf: bloom_filter memory usage
Introduce a new helper to calculate the bloom_filter memory usage.
The result as follows,
- before
16: bloom_filter flags 0x0
key 0B value 8B max_entries 65536 memlock 524288B
- after
16: bloom_filter flags 0x0
key 0B value 8B max_entries 65536 memlock 65856B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-9-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Yafang Shao
|
2f7e4ab2ca |
bpf: ringbuf memory usage
A new helper ringbuf_map_mem_usage() is introduced to calculate ringbuf
memory usage.
The result as follows,
- before
15: ringbuf name count_map flags 0x0
key 0B value 0B max_entries 65536 memlock 0B
- after
15: ringbuf name count_map flags 0x0
key 0B value 0B max_entries 65536 memlock 78424B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230305124615.12358-8-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Yafang Shao
|
2e89caf055 |
bpf: reuseport_array memory usage
A new helper is introduced to calculate reuseport_array memory usage.
The result as follows,
- before
14: reuseport_sockarray name count_map flags 0x0
key 4B value 8B max_entries 65536 memlock 1048576B
- after
14: reuseport_sockarray name count_map flags 0x0
key 4B value 8B max_entries 65536 memlock 524544B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-7-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Yafang Shao
|
cbb9b6068c |
bpf: stackmap memory usage
A new helper is introduced to get stackmap memory usage. Some small
memory allocations are ignored as their memory size is quite small
compared to the totol usage.
The result as follows,
- before
16: stack_trace name count_map flags 0x0
key 4B value 8B max_entries 65536 memlock 1048576B
- after
16: stack_trace name count_map flags 0x0
key 4B value 8B max_entries 65536 memlock 2097472B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-6-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Yafang Shao
|
1746d0555a |
bpf: arraymap memory usage
Introduce array_map_mem_usage() to calculate arraymap memory usage. In
this helper, some small memory allocations are ignored, like the
allocation of struct bpf_array_aux in prog_array. The inner_map_meta in
array_of_map is also ignored.
The result as follows,
- before
11: array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock 524288B
12: percpu_array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock 8912896B
13: perf_event_array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock 524288B
14: prog_array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock 524288B
15: cgroup_array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock 524288B
- after
11: array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock 524608B
12: percpu_array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock 17301824B
13: perf_event_array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock 524608B
14: prog_array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock 524608B
15: cgroup_array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock 524608B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-5-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Yafang Shao
|
304849a27b |
bpf: hashtab memory usage
htab_map_mem_usage() is introduced to calculate hashmap memory usage. In
this helper, some small memory allocations are ignore, as their size is
quite small compared with the total size. The inner_map_meta in
hash_of_map is also ignored.
The result for hashtab as follows,
- before this change
1: hash name count_map flags 0x1 <<<< no prealloc, fully set
key 16B value 24B max_entries 1048576 memlock 41943040B
2: hash name count_map flags 0x1 <<<< no prealloc, none set
key 16B value 24B max_entries 1048576 memlock 41943040B
3: hash name count_map flags 0x0 <<<< prealloc
key 16B value 24B max_entries 1048576 memlock 41943040B
The memlock is always a fixed size whatever it is preallocated or
not, and whatever the count of allocated elements is.
- after this change
1: hash name count_map flags 0x1 <<<< non prealloc, fully set
key 16B value 24B max_entries 1048576 memlock 117441536B
2: hash name count_map flags 0x1 <<<< non prealloc, non set
key 16B value 24B max_entries 1048576 memlock 16778240B
3: hash name count_map flags 0x0 <<<< prealloc
key 16B value 24B max_entries 1048576 memlock 109056000B
The memlock now is hashtab actually allocated.
The result for percpu hash map as follows,
- before this change
4: percpu_hash name count_map flags 0x0 <<<< prealloc
key 16B value 24B max_entries 1048576 memlock 822083584B
5: percpu_hash name count_map flags 0x1 <<<< no prealloc
key 16B value 24B max_entries 1048576 memlock 822083584B
- after this change
4: percpu_hash name count_map flags 0x0
key 16B value 24B max_entries 1048576 memlock 897582080B
5: percpu_hash name count_map flags 0x1
key 16B value 24B max_entries 1048576 memlock 922748736B
At worst, the difference can be 10x, for example,
- before this change
6: hash name count_map flags 0x0
key 4B value 4B max_entries 1048576 memlock 8388608B
- after this change
6: hash name count_map flags 0x0
key 4B value 4B max_entries 1048576 memlock 83889408B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20230305124615.12358-4-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Yafang Shao
|
41d5941e7f |
bpf: lpm_trie memory usage
trie_mem_usage() is introduced to calculate the lpm_trie memory usage.
Some small memory allocations are ignored. The inner node is also
ignored.
The result as follows,
- before
10: lpm_trie flags 0x1
key 8B value 8B max_entries 65536 memlock 1048576B
- after
10: lpm_trie flags 0x1
key 8B value 8B max_entries 65536 memlock 2291536B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-3-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Yafang Shao
|
90a5527d76 |
bpf: add new map ops ->map_mem_usage
Add a new map ops ->map_mem_usage to print the memory usage of a bpf map. This is a preparation for the followup change. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Link: https://lore.kernel.org/r/20230305124615.12358-2-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Jakub Kicinski
|
36e5e391a2 |
bpf-next-for-netdev
-----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTFp0I1jqZrAX+hPRXbK58LschIgwUCZAZsBwAKCRDbK58LschI g3W1AQCQnO6pqqX5Q2aYDAZPlZRtV2TRLjuqrQE0dHW/XLAbBgD/bgsAmiKhPSCG 2mTt6izpTQVlZB0e8KcDIvbYd9CE3Qc= =EjJQ -----END PGP SIGNATURE----- Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== pull-request: bpf-next 2023-03-06 We've added 85 non-merge commits during the last 13 day(s) which contain a total of 131 files changed, 7102 insertions(+), 1792 deletions(-). The main changes are: 1) Add skb and XDP typed dynptrs which allow BPF programs for more ergonomic and less brittle iteration through data and variable-sized accesses, from Joanne Koong. 2) Bigger batch of BPF verifier improvements to prepare for upcoming BPF open-coded iterators allowing for less restrictive looping capabilities, from Andrii Nakryiko. 3) Rework RCU enforcement in the verifier, add kptr_rcu and enforce BPF programs to NULL-check before passing such pointers into kfunc, from Alexei Starovoitov. 4) Add support for kptrs in percpu hashmaps, percpu LRU hashmaps and in local storage maps, from Kumar Kartikeya Dwivedi. 5) Add BPF verifier support for ST instructions in convert_ctx_access() which will help new -mcpu=v4 clang flag to start emitting them, from Eduard Zingerman. 6) Make uprobe attachment Android APK aware by supporting attachment to functions inside ELF objects contained in APKs via function names, from Daniel Müller. 7) Add a new flag BPF_F_TIMER_ABS flag for bpf_timer_start() helper to start the timer with absolute expiration value instead of relative one, from Tero Kristo. 8) Add a new kfunc bpf_cgroup_from_id() to look up cgroups via id, from Tejun Heo. 9) Extend libbpf to support users manually attaching kprobes/uprobes in the legacy/perf/link mode, from Menglong Dong. 10) Implement workarounds in the mips BPF JIT for DADDI/R4000, from Jiaxun Yang. 11) Enable mixing bpf2bpf and tailcalls for the loongarch BPF JIT, from Hengqi Chen. 12) Extend BPF instruction set doc with describing the encoding of BPF instructions in terms of how bytes are stored under big/little endian, from Jose E. Marchesi. 13) Follow-up to enable kfunc support for riscv BPF JIT, from Pu Lehui. 14) Fix bpf_xdp_query() backwards compatibility on old kernels, from Yonghong Song. 15) Fix BPF selftest cross compilation with CLANG_CROSS_FLAGS, from Florent Revest. 16) Improve bpf_cpumask_ma to only allocate one bpf_mem_cache, from Hou Tao. 17) Fix BPF verifier's check_subprogs to not unnecessarily mark a subprogram with has_tail_call, from Ilya Leoshkevich. 18) Fix arm syscall regs spec in libbpf's bpf_tracing.h, from Puranjay Mohan. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (85 commits) selftests/bpf: Add test for legacy/perf kprobe/uprobe attach mode selftests/bpf: Split test_attach_probe into multi subtests libbpf: Add support to set kprobe/uprobe attach mode tools/resolve_btfids: Add /libsubcmd to .gitignore bpf: add support for fixed-size memory pointer returns for kfuncs bpf: generalize dynptr_get_spi to be usable for iters bpf: mark PTR_TO_MEM as non-null register type bpf: move kfunc_call_arg_meta higher in the file bpf: ensure that r0 is marked scratched after any function call bpf: fix visit_insn()'s detection of BPF_FUNC_timer_set_callback helper bpf: clean up visit_insn()'s instruction processing selftests/bpf: adjust log_fixup's buffer size for proper truncation bpf: honor env->test_state_freq flag in is_state_visited() selftests/bpf: enhance align selftest's expected log matching bpf: improve regsafe() checks for PTR_TO_{MEM,BUF,TP_BUFFER} bpf: improve stack slot state printing selftests/bpf: Disassembler tests for verifier.c:convert_ctx_access() selftests/bpf: test if pointer type is tracked for BPF_ST_MEM bpf: allow ctx writes using BPF_ST_MEM instruction bpf: Use separate RCU callbacks for freeing selem ... ==================== Link: https://lore.kernel.org/r/20230307004346.27578-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
||
|
Jakub Kicinski
|
757b56a6c7 |
bpf-for-netdev
-----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTFp0I1jqZrAX+hPRXbK58LschIgwUCZAZZ1wAKCRDbK58LschI g4fcAQDYVsICeBDmhdBdZs7Kb91/s6SrU6B0jy4zs0gOIBBOhgD7B3jt3dMTD2tp rPLHlv6uUoYS7mbZsrZi/XjVw8UmewM= =VUnr -----END PGP SIGNATURE----- Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf Daniel Borkmann says: ==================== pull-request: bpf 2023-03-06 We've added 8 non-merge commits during the last 7 day(s) which contain a total of 9 files changed, 64 insertions(+), 18 deletions(-). The main changes are: 1) Fix BTF resolver for DATASEC sections when a VAR points at a modifier, that is, keep resolving such instances instead of bailing out, from Lorenz Bauer. 2) Fix BPF test framework with regards to xdp_frame info misplacement in the "live packet" code, from Alexander Lobakin. 3) Fix an infinite loop in BPF sockmap code for TCP/UDP/AF_UNIX, from Liu Jian. 4) Fix a build error for riscv BPF JIT under PERF_EVENTS=n, from Randy Dunlap. 5) Several BPF doc fixes with either broken links or external instead of internal doc links, from Bagas Sanjaya. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: selftests/bpf: check that modifier resolves after pointer btf: fix resolving BTF_KIND_VAR after ARRAY, STRUCT, UNION, PTR bpf, test_run: fix &xdp_frame misplacement for LIVE_FRAMES bpf, doc: Link to submitting-patches.rst for general patch submission info bpf, doc: Do not link to docs.kernel.org for kselftest link bpf, sockmap: Fix an infinite loop error when len is 0 in tcp_bpf_recvmsg_parser() riscv, bpf: Fix patch_text implicit declaration bpf, docs: Fix link to BTF doc ==================== Link: https://lore.kernel.org/r/20230306215944.11981-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
||
|
Lorenz Bauer
|
9b459804ff |
btf: fix resolving BTF_KIND_VAR after ARRAY, STRUCT, UNION, PTR
btf_datasec_resolve contains a bug that causes the following BTF
to fail loading:
[1] DATASEC a size=2 vlen=2
type_id=4 offset=0 size=1
type_id=7 offset=1 size=1
[2] INT (anon) size=1 bits_offset=0 nr_bits=8 encoding=(none)
[3] PTR (anon) type_id=2
[4] VAR a type_id=3 linkage=0
[5] INT (anon) size=1 bits_offset=0 nr_bits=8 encoding=(none)
[6] TYPEDEF td type_id=5
[7] VAR b type_id=6 linkage=0
This error message is printed during btf_check_all_types:
[1] DATASEC a size=2 vlen=2
type_id=7 offset=1 size=1 Invalid type
By tracing btf_*_resolve we can pinpoint the problem:
btf_datasec_resolve(depth: 1, type_id: 1, mode: RESOLVE_TBD) = 0
btf_var_resolve(depth: 2, type_id: 4, mode: RESOLVE_TBD) = 0
btf_ptr_resolve(depth: 3, type_id: 3, mode: RESOLVE_PTR) = 0
btf_var_resolve(depth: 2, type_id: 4, mode: RESOLVE_PTR) = 0
btf_datasec_resolve(depth: 1, type_id: 1, mode: RESOLVE_PTR) = -22
The last invocation of btf_datasec_resolve should invoke btf_var_resolve
by means of env_stack_push, instead it returns EINVAL. The reason is that
env_stack_push is never executed for the second VAR.
if (!env_type_is_resolve_sink(env, var_type) &&
!env_type_is_resolved(env, var_type_id)) {
env_stack_set_next_member(env, i + 1);
return env_stack_push(env, var_type, var_type_id);
}
env_type_is_resolve_sink() changes its behaviour based on resolve_mode.
For RESOLVE_PTR, we can simplify the if condition to the following:
(btf_type_is_modifier() || btf_type_is_ptr) && !env_type_is_resolved()
Since we're dealing with a VAR the clause evaluates to false. This is
not sufficient to trigger the bug however. The log output and EINVAL
are only generated if btf_type_id_size() fails.
if (!btf_type_id_size(btf, &type_id, &type_size)) {
btf_verifier_log_vsi(env, v->t, vsi, "Invalid type");
return -EINVAL;
}
Most types are sized, so for example a VAR referring to an INT is not a
problem. The bug is only triggered if a VAR points at a modifier. Since
we skipped btf_var_resolve that modifier was also never resolved, which
means that btf_resolved_type_id returns 0 aka VOID for the modifier.
This in turn causes btf_type_id_size to return NULL, triggering EINVAL.
To summarise, the following conditions are necessary:
- VAR pointing at PTR, STRUCT, UNION or ARRAY
- Followed by a VAR pointing at TYPEDEF, VOLATILE, CONST, RESTRICT or
TYPE_TAG
The fix is to reset resolve_mode to RESOLVE_TBD before attempting to
resolve a VAR from a DATASEC.
Fixes:
|
||
|
Andrii Nakryiko
|
f4b4eee616 |
bpf: add support for fixed-size memory pointer returns for kfuncs
Support direct fixed-size (and for now, read-only) memory access when kfunc's return type is a pointer to non-struct type. Calculate type size and let BPF program access that many bytes directly. This is crucial for numbers iterator. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230302235015.2044271-13-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
a461f5adf1 |
bpf: generalize dynptr_get_spi to be usable for iters
Generalize the logic of fetching special stack slot object state using spi (stack slot index). This will be used by STACK_ITER logic next. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230302235015.2044271-12-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
d5271c5b19 |
bpf: mark PTR_TO_MEM as non-null register type
PTR_TO_MEM register without PTR_MAYBE_NULL is indeed non-null. This is important for BPF verifier to be able to prune guaranteed not to be taken branches. This is always the case with open-coded iterators. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230302235015.2044271-11-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
d0e1ac2279 |
bpf: move kfunc_call_arg_meta higher in the file
Move struct bpf_kfunc_call_arg_meta higher in the file and put it next to struct bpf_call_arg_meta, so it can be used from more functions. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230302235015.2044271-10-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
553a64a85c |
bpf: ensure that r0 is marked scratched after any function call
r0 is important (unless called function is void-returning, but that's taken care of by print_verifier_state() anyways) in verifier logs. Currently for helpers we seem to print it in verifier log, but for kfuncs we don't. Instead of figuring out where in the maze of code we accidentally set r0 as scratched for helpers and why we don't do that for kfuncs, just enforce that after any function call r0 is marked as scratched. Also, perhaps, we should reconsider "scratched" terminology, as it's mightily confusing. "Touched" would seem more appropriate. But I left that for follow ups for now. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230302235015.2044271-9-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
c1ee85a980 |
bpf: fix visit_insn()'s detection of BPF_FUNC_timer_set_callback helper
It's not correct to assume that any BPF_CALL instruction is a helper call. Fix visit_insn()'s detection of bpf_timer_set_callback() helper by also checking insn->code == 0. For kfuncs insn->code would be set to BPF_PSEUDO_KFUNC_CALL, and for subprog calls it will be BPF_PSEUDO_CALL. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230302235015.2044271-8-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
653ae3a874 |
bpf: clean up visit_insn()'s instruction processing
Instead of referencing processed instruction repeatedly as insns[t] throughout entire visit_insn() function, take a local insn pointer and work with it in a cleaner way. It makes enhancing this function further a bit easier as well. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230302235015.2044271-7-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
98ddcf389d |
bpf: honor env->test_state_freq flag in is_state_visited()
env->test_state_freq flag can be set by user by passing BPF_F_TEST_STATE_FREQ program flag. This is used in a bunch of selftests to have predictable state checkpoints at every jump and so on. Currently, bounded loop handling heuristic ignores this flag if number of processed jumps and/or number of processed instructions is below some thresholds, which throws off that reliable state checkpointing. Honor this flag in all circumstances by disabling heuristic if env->test_state_freq is set. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230302235015.2044271-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
567da5d253 |
bpf: improve regsafe() checks for PTR_TO_{MEM,BUF,TP_BUFFER}
Teach regsafe() logic to handle PTR_TO_MEM, PTR_TO_BUF, and
PTR_TO_TP_BUFFER similarly to PTR_TO_MAP_{KEY,VALUE}. That is, instead of
exact match for var_off and range, use tnum_in() and range_within()
checks, allowing more general verified state to subsume more specific
current state. This allows to match wider range of valid and safe
states, speeding up verification and detecting wider range of equivalent
states for upcoming open-coded iteration looping logic.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230302235015.2044271-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Andrii Nakryiko
|
d54e0f6c1a |
bpf: improve stack slot state printing
Improve stack slot state printing to provide more useful and relevant information, especially for dynptrs. While previously we'd see something like: 8: (85) call bpf_ringbuf_reserve_dynptr#198 ; R0_w=scalar() fp-8_w=dddddddd fp-16_w=dddddddd refs=2 Now we'll see way more useful: 8: (85) call bpf_ringbuf_reserve_dynptr#198 ; R0_w=scalar() fp-16_w=dynptr_ringbuf(ref_id=2) refs=2 I experimented with printing the range of slots taken by dynptr, something like: fp-16..8_w=dynptr_ringbuf(ref_id=2) But it felt very awkward and pretty useless. So we print the lowest address (most negative offset) only. The general structure of this code is now also set up for easier extension and will accommodate ITER slots naturally. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230302235015.2044271-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Eduard Zingerman
|
0d80a619c1 |
bpf: allow ctx writes using BPF_ST_MEM instruction
Lift verifier restriction to use BPF_ST_MEM instructions to write to
context data structures. This requires the following changes:
- verifier.c:do_check() for BPF_ST updated to:
- no longer forbid writes to registers of type PTR_TO_CTX;
- track dst_reg type in the env->insn_aux_data[...].ptr_type field
(same way it is done for BPF_STX and BPF_LDX instructions).
- verifier.c:convert_ctx_access() and various callbacks invoked by
it are updated to handled BPF_ST instruction alongside BPF_STX.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230304011247.566040-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Kumar Kartikeya Dwivedi
|
e768e3c5aa |
bpf: Use separate RCU callbacks for freeing selem
Martin suggested that instead of using a byte in the hole (which he has
a use for in his future patch) in bpf_local_storage_elem, we can
dispatch a different call_rcu callback based on whether we need to free
special fields in bpf_local_storage_elem data. The free path, described
in commit
|
||
|
Alexei Starovoitov
|
6fcd486b3a |
bpf: Refactor RCU enforcement in the verifier.
bpf_rcu_read_lock/unlock() are only available in clang compiled kernels. Lack of such key mechanism makes it impossible for sleepable bpf programs to use RCU pointers. Allow bpf_rcu_read_lock/unlock() in GCC compiled kernels (though GCC doesn't support btf_type_tag yet) and allowlist certain field dereferences in important data structures like tast_struct, cgroup, socket that are used by sleepable programs either as RCU pointer or full trusted pointer (which is valid outside of RCU CS). Use BTF_TYPE_SAFE_RCU and BTF_TYPE_SAFE_TRUSTED macros for such tagging. They will be removed once GCC supports btf_type_tag. With that refactor check_ptr_to_btf_access(). Make it strict in enforcing PTR_TRUSTED and PTR_UNTRUSTED while deprecating old PTR_TO_BTF_ID without modifier flags. There is a chance that this strict enforcement might break existing programs (especially on GCC compiled kernels), but this cleanup has to start sooner than later. Note PTR_TO_CTX access still yields old deprecated PTR_TO_BTF_ID. Once it's converted to strict PTR_TRUSTED or PTR_UNTRUSTED the kfuncs and helpers will be able to default to KF_TRUSTED_ARGS. KF_RCU will remain as a weaker version of KF_TRUSTED_ARGS where obj refcnt could be 0. Adjust rcu_read_lock selftest to run on gcc and clang compiled kernels. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/20230303041446.3630-7-alexei.starovoitov@gmail.com |
||
|
Alexei Starovoitov
|
20c09d92fa |
bpf: Introduce kptr_rcu.
The life time of certain kernel structures like 'struct cgroup' is protected by RCU.
Hence it's safe to dereference them directly from __kptr tagged pointers in bpf maps.
The resulting pointer is MEM_RCU and can be passed to kfuncs that expect KF_RCU.
Derefrence of other kptr-s returns PTR_UNTRUSTED.
For example:
struct map_value {
struct cgroup __kptr *cgrp;
};
SEC("tp_btf/cgroup_mkdir")
int BPF_PROG(test_cgrp_get_ancestors, struct cgroup *cgrp_arg, const char *path)
{
struct cgroup *cg, *cg2;
cg = bpf_cgroup_acquire(cgrp_arg); // cg is PTR_TRUSTED and ref_obj_id > 0
bpf_kptr_xchg(&v->cgrp, cg);
cg2 = v->cgrp; // This is new feature introduced by this patch.
// cg2 is PTR_MAYBE_NULL | MEM_RCU.
// When cg2 != NULL, it's a valid cgroup, but its percpu_ref could be zero
if (cg2)
bpf_cgroup_ancestor(cg2, level); // safe to do.
}
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/bpf/20230303041446.3630-4-alexei.starovoitov@gmail.com
|
||
|
Alexei Starovoitov
|
8d093b4e95 |
bpf: Mark cgroups and dfl_cgrp fields as trusted.
bpf programs sometimes do: bpf_cgrp_storage_get(&map, task->cgroups->dfl_cgrp, ...); It is safe to do, because cgroups->dfl_cgrp pointer is set diring init and never changes. The task->cgroups is also never NULL. It is also set during init and will change when task switches cgroups. For any trusted task pointer dereference of cgroups and dfl_cgrp should yield trusted pointers. The verifier wasn't aware of this. Hence in gcc compiled kernels task->cgroups dereference was producing PTR_TO_BTF_ID without modifiers while in clang compiled kernels the verifier recognizes __rcu tag in cgroups field and produces PTR_TO_BTF_ID | MEM_RCU | MAYBE_NULL. Tag cgroups and dfl_cgrp as trusted to equalize clang and gcc behavior. When GCC supports btf_type_tag such tagging will done directly in the type. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: David Vernet <void@manifault.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/bpf/20230303041446.3630-3-alexei.starovoitov@gmail.com |
||
|
Alexei Starovoitov
|
03b77e17ae |
bpf: Rename __kptr_ref -> __kptr and __kptr -> __kptr_untrusted.
__kptr meant to store PTR_UNTRUSTED kernel pointers inside bpf maps. The concept felt useful, but didn't get much traction, since bpf_rdonly_cast() was added soon after and bpf programs received a simpler way to access PTR_UNTRUSTED kernel pointers without going through restrictive __kptr usage. Rename __kptr_ref -> __kptr and __kptr -> __kptr_untrusted to indicate its intended usage. The main goal of __kptr_untrusted was to read/write such pointers directly while bpf_kptr_xchg was a mechanism to access refcnted kernel pointers. The next patch will allow RCU protected __kptr access with direct read. At that point __kptr_untrusted will be deprecated. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/20230303041446.3630-2-alexei.starovoitov@gmail.com |
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Tero Kristo
|
f71f853049 |
bpf: Add support for absolute value BPF timers
Add a new flag BPF_F_TIMER_ABS that can be passed to bpf_timer_start() to start an absolute value timer instead of the default relative value. This makes the timer expire at an exact point in time, instead of a time with latencies induced by both the BPF and timer subsystems. Suggested-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: Tero Kristo <tero.kristo@linux.intel.com> Link: https://lore.kernel.org/r/20230302114614.2985072-2-tero.kristo@linux.intel.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Tejun Heo
|
c501bf55c8 |
bpf: Make bpf_get_current_[ancestor_]cgroup_id() available for all program types
These helpers are safe to call from any context and there's no reason to
restrict access to them. Remove them from bpf_trace and filter lists and add
to bpf_base_func_proto() under perfmon_capable().
v2: After consulting with Andrii, relocated in bpf_base_func_proto() so that
they require bpf_capable() but not perfomon_capable() as it doesn't read
from or affect others on the system.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/ZAD8QyoszMZiTzBY@slm.duckdns.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Joanne Koong
|
c45eac537b |
bpf: Fix bpf_dynptr_slice{_rdwr} to return NULL instead of 0
Change bpf_dynptr_slice and bpf_dynptr_slice_rdwr to return NULL instead
of 0, in accordance with the codebase guidelines.
Fixes:
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David Vernet
|
7ce60b110e |
bpf: Fix doxygen comments for dynptr slice kfuncs
In commit |
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Kumar Kartikeya Dwivedi
|
9db44fdd81 |
bpf: Support kptrs in local storage maps
Enable support for kptrs in local storage maps by wiring up the freeing of these kptrs from map value. Freeing of bpf_local_storage_map is only delayed in case there are special fields, therefore bpf_selem_free_* path can also only dereference smap safely in that case. This is recorded using a bool utilizing a hole in bpF_local_storage_elem. It could have been tagged in the pointer value smap using the lowest bit (since alignment > 1), but since there was already a hole I went with the simpler option. Only the map structure freeing is delayed using RCU barriers, as the buckets aren't used when selem is being freed, so they can be freed once all readers of the bucket lists can no longer access it. Cc: Martin KaFai Lau <martin.lau@kernel.org> Cc: KP Singh <kpsingh@kernel.org> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20230225154010.391965-3-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Kumar Kartikeya Dwivedi
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65334e64a4 |
bpf: Support kptrs in percpu hashmap and percpu LRU hashmap
Enable support for kptrs in percpu BPF hashmap and percpu BPF LRU hashmap by wiring up the freeing of these kptrs from percpu map elements. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20230225154010.391965-2-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Joanne Koong
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66e3a13e7c |
bpf: Add bpf_dynptr_slice and bpf_dynptr_slice_rdwr
Two new kfuncs are added, bpf_dynptr_slice and bpf_dynptr_slice_rdwr. The user must pass in a buffer to store the contents of the data slice if a direct pointer to the data cannot be obtained. For skb and xdp type dynptrs, these two APIs are the only way to obtain a data slice. However, for other types of dynptrs, there is no difference between bpf_dynptr_slice(_rdwr) and bpf_dynptr_data. For skb type dynptrs, the data is copied into the user provided buffer if any of the data is not in the linear portion of the skb. For xdp type dynptrs, the data is copied into the user provided buffer if the data is between xdp frags. If the skb is cloned and a call to bpf_dynptr_data_rdwr is made, then the skb will be uncloned (see bpf_unclone_prologue()). Please note that any bpf_dynptr_write() automatically invalidates any prior data slices of the skb dynptr. This is because the skb may be cloned or may need to pull its paged buffer into the head. As such, any bpf_dynptr_write() will automatically have its prior data slices invalidated, even if the write is to data in the skb head of an uncloned skb. Please note as well that any other helper calls that change the underlying packet buffer (eg bpf_skb_pull_data()) invalidates any data slices of the skb dynptr as well, for the same reasons. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Link: https://lore.kernel.org/r/20230301154953.641654-10-joannelkoong@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Joanne Koong
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05421aecd4 |
bpf: Add xdp dynptrs
Add xdp dynptrs, which are dynptrs whose underlying pointer points to a xdp_buff. The dynptr acts on xdp data. xdp dynptrs have two main benefits. One is that they allow operations on sizes that are not statically known at compile-time (eg variable-sized accesses). Another is that parsing the packet data through dynptrs (instead of through direct access of xdp->data and xdp->data_end) can be more ergonomic and less brittle (eg does not need manual if checking for being within bounds of data_end). For reads and writes on the dynptr, this includes reading/writing from/to and across fragments. Data slices through the bpf_dynptr_data API are not supported; instead bpf_dynptr_slice() and bpf_dynptr_slice_rdwr() should be used. For examples of how xdp dynptrs can be used, please see the attached selftests. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Link: https://lore.kernel.org/r/20230301154953.641654-9-joannelkoong@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Joanne Koong
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b5964b968a |
bpf: Add skb dynptrs
Add skb dynptrs, which are dynptrs whose underlying pointer points to a skb. The dynptr acts on skb data. skb dynptrs have two main benefits. One is that they allow operations on sizes that are not statically known at compile-time (eg variable-sized accesses). Another is that parsing the packet data through dynptrs (instead of through direct access of skb->data and skb->data_end) can be more ergonomic and less brittle (eg does not need manual if checking for being within bounds of data_end). For bpf prog types that don't support writes on skb data, the dynptr is read-only (bpf_dynptr_write() will return an error) For reads and writes through the bpf_dynptr_read() and bpf_dynptr_write() interfaces, reading and writing from/to data in the head as well as from/to non-linear paged buffers is supported. Data slices through the bpf_dynptr_data API are not supported; instead bpf_dynptr_slice() and bpf_dynptr_slice_rdwr() (added in subsequent commit) should be used. For examples of how skb dynptrs can be used, please see the attached selftests. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Link: https://lore.kernel.org/r/20230301154953.641654-8-joannelkoong@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Joanne Koong
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d96d937d7c |
bpf: Add __uninit kfunc annotation
This patch adds __uninit as a kfunc annotation. This will be useful for scenarios such as for example in dynptrs, indicating whether the dynptr should be checked by the verifier as an initialized or an uninitialized dynptr. Without this annotation, the alternative would be needing to hard-code in the verifier the specific kfunc to indicate that arg should be treated as an uninitialized arg. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Link: https://lore.kernel.org/r/20230301154953.641654-7-joannelkoong@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Joanne Koong
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485ec51ef9 |
bpf: Refactor verifier dynptr into get_dynptr_arg_reg
This commit refactors the logic for determining which register in a function is the dynptr into "get_dynptr_arg_reg". This will be used in the future when the dynptr reg for BPF_FUNC_dynptr_write will need to be obtained in order to support writes for skb dynptrs. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Link: https://lore.kernel.org/r/20230301154953.641654-6-joannelkoong@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Joanne Koong
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1d18feb2c9 |
bpf: Allow initializing dynptrs in kfuncs
This change allows kfuncs to take in an uninitialized dynptr as a parameter. Before this change, only helper functions could successfully use uninitialized dynptrs. This change moves the memory access check (including stack state growing and slot marking) into process_dynptr_func(), which both helpers and kfuncs call into. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Link: https://lore.kernel.org/r/20230301154953.641654-4-joannelkoong@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Joanne Koong
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7e0dac2807 |
bpf: Refactor process_dynptr_func
This change cleans up process_dynptr_func's flow to be more intuitive and updates some comments with more context. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Link: https://lore.kernel.org/r/20230301154953.641654-3-joannelkoong@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Joanne Koong
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2f46439346 |
bpf: Support "sk_buff" and "xdp_buff" as valid kfunc arg types
The bpf mirror of the in-kernel sk_buff and xdp_buff data structures are __sk_buff and xdp_md. Currently, when we pass in the program ctx to a kfunc where the program ctx is a skb or xdp buffer, we reject the program if the in-kernel definition is sk_buff/xdp_buff instead of __sk_buff/xdp_md. This change allows "sk_buff <--> __sk_buff" and "xdp_buff <--> xdp_md" to be recognized as valid matches. The user program may pass in their program ctx as a __sk_buff or xdp_md, and the in-kernel definition of the kfunc may define this arg as a sk_buff or xdp_buff. Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Link: https://lore.kernel.org/r/20230301154953.641654-2-joannelkoong@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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David Vernet
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30a2d8328d |
bpf: Fix bpf_cgroup_from_id() doxygen header
In commit |
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Linus Torvalds
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3822a7c409 |
- Daniel Verkamp has contributed a memfd series ("mm/memfd: add
F_SEAL_EXEC") which permits the setting of the memfd execute bit at
memfd creation time, with the option of sealing the state of the X bit.
- Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset()
thread-safe for pmd unshare") which addresses a rare race condition
related to PMD unsharing.
- Several folioification patch serieses from Matthew Wilcox, Vishal
Moola, Sidhartha Kumar and Lorenzo Stoakes
- Johannes Weiner has a series ("mm: push down lock_page_memcg()") which
does perform some memcg maintenance and cleanup work.
- SeongJae Park has added DAMOS filtering to DAMON, with the series
"mm/damon/core: implement damos filter". These filters provide users
with finer-grained control over DAMOS's actions. SeongJae has also done
some DAMON cleanup work.
- Kairui Song adds a series ("Clean up and fixes for swap").
- Vernon Yang contributed the series "Clean up and refinement for maple
tree".
- Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It
adds to MGLRU an LRU of memcgs, to improve the scalability of global
reclaim.
- David Hildenbrand has added some userfaultfd cleanup work in the
series "mm: uffd-wp + change_protection() cleanups".
- Christoph Hellwig has removed the generic_writepages() library
function in the series "remove generic_writepages".
- Baolin Wang has performed some maintenance on the compaction code in
his series "Some small improvements for compaction".
- Sidhartha Kumar is doing some maintenance work on struct page in his
series "Get rid of tail page fields".
- David Hildenbrand contributed some cleanup, bugfixing and
generalization of pte management and of pte debugging in his series "mm:
support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap
PTEs".
- Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation
flag in the series "Discard __GFP_ATOMIC".
- Sergey Senozhatsky has improved zsmalloc's memory utilization with his
series "zsmalloc: make zspage chain size configurable".
- Joey Gouly has added prctl() support for prohibiting the creation of
writeable+executable mappings. The previous BPF-based approach had
shortcomings. See "mm: In-kernel support for memory-deny-write-execute
(MDWE)".
- Waiman Long did some kmemleak cleanup and bugfixing in the series
"mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF".
- T.J. Alumbaugh has contributed some MGLRU cleanup work in his series
"mm: multi-gen LRU: improve".
- Jiaqi Yan has provided some enhancements to our memory error
statistics reporting, mainly by presenting the statistics on a per-node
basis. See the series "Introduce per NUMA node memory error
statistics".
- Mel Gorman has a second and hopefully final shot at fixing a CPU-hog
regression in compaction via his series "Fix excessive CPU usage during
compaction".
- Christoph Hellwig does some vmalloc maintenance work in the series
"cleanup vfree and vunmap".
- Christoph Hellwig has removed block_device_operations.rw_page() in ths
series "remove ->rw_page".
- We get some maple_tree improvements and cleanups in Liam Howlett's
series "VMA tree type safety and remove __vma_adjust()".
- Suren Baghdasaryan has done some work on the maintainability of our
vm_flags handling in the series "introduce vm_flags modifier functions".
- Some pagemap cleanup and generalization work in Mike Rapoport's series
"mm, arch: add generic implementation of pfn_valid() for FLATMEM" and
"fixups for generic implementation of pfn_valid()"
- Baoquan He has done some work to make /proc/vmallocinfo and
/proc/kcore better represent the real state of things in his series
"mm/vmalloc.c: allow vread() to read out vm_map_ram areas".
- Jason Gunthorpe rationalized the GUP system's interface to the rest of
the kernel in the series "Simplify the external interface for GUP".
- SeongJae Park wishes to migrate people from DAMON's debugfs interface
over to its sysfs interface. To support this, we'll temporarily be
printing warnings when people use the debugfs interface. See the series
"mm/damon: deprecate DAMON debugfs interface".
- Andrey Konovalov provided the accurately named "lib/stackdepot: fixes
and clean-ups" series.
- Huang Ying has provided a dramatic reduction in migration's TLB flush
IPI rates with the series "migrate_pages(): batch TLB flushing".
- Arnd Bergmann has some objtool fixups in "objtool warning fixes".
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Merge tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- Daniel Verkamp has contributed a memfd series ("mm/memfd: add
F_SEAL_EXEC") which permits the setting of the memfd execute bit at
memfd creation time, with the option of sealing the state of the X
bit.
- Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset()
thread-safe for pmd unshare") which addresses a rare race condition
related to PMD unsharing.
- Several folioification patch serieses from Matthew Wilcox, Vishal
Moola, Sidhartha Kumar and Lorenzo Stoakes
- Johannes Weiner has a series ("mm: push down lock_page_memcg()")
which does perform some memcg maintenance and cleanup work.
- SeongJae Park has added DAMOS filtering to DAMON, with the series
"mm/damon/core: implement damos filter".
These filters provide users with finer-grained control over DAMOS's
actions. SeongJae has also done some DAMON cleanup work.
- Kairui Song adds a series ("Clean up and fixes for swap").
- Vernon Yang contributed the series "Clean up and refinement for maple
tree".
- Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It
adds to MGLRU an LRU of memcgs, to improve the scalability of global
reclaim.
- David Hildenbrand has added some userfaultfd cleanup work in the
series "mm: uffd-wp + change_protection() cleanups".
- Christoph Hellwig has removed the generic_writepages() library
function in the series "remove generic_writepages".
- Baolin Wang has performed some maintenance on the compaction code in
his series "Some small improvements for compaction".
- Sidhartha Kumar is doing some maintenance work on struct page in his
series "Get rid of tail page fields".
- David Hildenbrand contributed some cleanup, bugfixing and
generalization of pte management and of pte debugging in his series
"mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with
swap PTEs".
- Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation
flag in the series "Discard __GFP_ATOMIC".
- Sergey Senozhatsky has improved zsmalloc's memory utilization with
his series "zsmalloc: make zspage chain size configurable".
- Joey Gouly has added prctl() support for prohibiting the creation of
writeable+executable mappings.
The previous BPF-based approach had shortcomings. See "mm: In-kernel
support for memory-deny-write-execute (MDWE)".
- Waiman Long did some kmemleak cleanup and bugfixing in the series
"mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF".
- T.J. Alumbaugh has contributed some MGLRU cleanup work in his series
"mm: multi-gen LRU: improve".
- Jiaqi Yan has provided some enhancements to our memory error
statistics reporting, mainly by presenting the statistics on a
per-node basis. See the series "Introduce per NUMA node memory error
statistics".
- Mel Gorman has a second and hopefully final shot at fixing a CPU-hog
regression in compaction via his series "Fix excessive CPU usage
during compaction".
- Christoph Hellwig does some vmalloc maintenance work in the series
"cleanup vfree and vunmap".
- Christoph Hellwig has removed block_device_operations.rw_page() in
ths series "remove ->rw_page".
- We get some maple_tree improvements and cleanups in Liam Howlett's
series "VMA tree type safety and remove __vma_adjust()".
- Suren Baghdasaryan has done some work on the maintainability of our
vm_flags handling in the series "introduce vm_flags modifier
functions".
- Some pagemap cleanup and generalization work in Mike Rapoport's
series "mm, arch: add generic implementation of pfn_valid() for
FLATMEM" and "fixups for generic implementation of pfn_valid()"
- Baoquan He has done some work to make /proc/vmallocinfo and
/proc/kcore better represent the real state of things in his series
"mm/vmalloc.c: allow vread() to read out vm_map_ram areas".
- Jason Gunthorpe rationalized the GUP system's interface to the rest
of the kernel in the series "Simplify the external interface for
GUP".
- SeongJae Park wishes to migrate people from DAMON's debugfs interface
over to its sysfs interface. To support this, we'll temporarily be
printing warnings when people use the debugfs interface. See the
series "mm/damon: deprecate DAMON debugfs interface".
- Andrey Konovalov provided the accurately named "lib/stackdepot: fixes
and clean-ups" series.
- Huang Ying has provided a dramatic reduction in migration's TLB flush
IPI rates with the series "migrate_pages(): batch TLB flushing".
- Arnd Bergmann has some objtool fixups in "objtool warning fixes".
* tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits)
include/linux/migrate.h: remove unneeded externs
mm/memory_hotplug: cleanup return value handing in do_migrate_range()
mm/uffd: fix comment in handling pte markers
mm: change to return bool for isolate_movable_page()
mm: hugetlb: change to return bool for isolate_hugetlb()
mm: change to return bool for isolate_lru_page()
mm: change to return bool for folio_isolate_lru()
objtool: add UACCESS exceptions for __tsan_volatile_read/write
kmsan: disable ftrace in kmsan core code
kasan: mark addr_has_metadata __always_inline
mm: memcontrol: rename memcg_kmem_enabled()
sh: initialize max_mapnr
m68k/nommu: add missing definition of ARCH_PFN_OFFSET
mm: percpu: fix incorrect size in pcpu_obj_full_size()
maple_tree: reduce stack usage with gcc-9 and earlier
mm: page_alloc: call panic() when memoryless node allocation fails
mm: multi-gen LRU: avoid futile retries
migrate_pages: move THP/hugetlb migration support check to simplify code
migrate_pages: batch flushing TLB
migrate_pages: share more code between _unmap and _move
...
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Tejun Heo
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332ea1f697 |
bpf: Add bpf_cgroup_from_id() kfunc
cgroup ID is an userspace-visible 64bit value uniquely identifying a given cgroup. As the IDs are used widely, it's useful to be able to look up the matching cgroups. Add bpf_cgroup_from_id(). v2: Separate out selftest into its own patch as suggested by Alexei. Signed-off-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/Y/bBaG96t0/gQl9/@slm.duckdns.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Ilya Leoshkevich
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df2ccc180a |
bpf: Check for helper calls in check_subprogs()
The condition src_reg != BPF_PSEUDO_CALL && imm == BPF_FUNC_tail_call may be satisfied by a kfunc call. This would lead to unnecessarily setting has_tail_call. Use src_reg == 0 instead. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/20230220163756.753713-1-iii@linux.ibm.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Hou Tao
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5d5de3a431 |
bpf: Only allocate one bpf_mem_cache for bpf_cpumask_ma
The size of bpf_cpumask is fixed, so there is no need to allocate many bpf_mem_caches for bpf_cpumask_ma, just one bpf_mem_cache is enough. Also add comments for bpf_mem_alloc_init() in bpf_mem_alloc.h to prevent future miuse. Signed-off-by: Hou Tao <houtao1@huawei.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20230216024821.2202916-1-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Kumar Kartikeya Dwivedi
|
dbd8d22863 |
bpf: Wrap register invalidation with a helper
Typically, verifier should use env->allow_ptr_leaks when invaliding
registers for users that don't have CAP_PERFMON or CAP_SYS_ADMIN to
avoid leaking the pointer value. This is similar in spirit to
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Kumar Kartikeya Dwivedi
|
da03e43a8c |
bpf: Fix check_reg_type for PTR_TO_BTF_ID
The current code does type matching for the case where reg->type is PTR_TO_BTF_ID or has the PTR_TRUSTED flag. However, this only needs to occur for non-MEM_ALLOC and non-MEM_PERCPU cases, but will include both as per the current code. The MEM_ALLOC case with or without PTR_TRUSTED needs to be handled specially by the code for type_is_alloc case, while MEM_PERCPU case must be ignored. Hence, to restore correct behavior and for clarity, explicitly list out the handled PTR_TO_BTF_ID types which should be handled for each case using a switch statement. Helpers currently only take: PTR_TO_BTF_ID PTR_TO_BTF_ID | PTR_TRUSTED PTR_TO_BTF_ID | MEM_RCU PTR_TO_BTF_ID | MEM_ALLOC PTR_TO_BTF_ID | MEM_PERCPU PTR_TO_BTF_ID | MEM_PERCPU | PTR_TRUSTED This fix was also described (for the MEM_ALLOC case) in [0]. [0]: https://lore.kernel.org/bpf/20221121160657.h6z7xuvedybp5y7s@apollo Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20230221200646.2500777-6-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Kumar Kartikeya Dwivedi
|
521d3c0a17 |
bpf: Remove unused MEM_ALLOC | PTR_TRUSTED checks
The plan is to supposedly tag everything with PTR_TRUSTED eventually, however those changes should bring in their respective code, instead of leaving it around right now. It is arguable whether PTR_TRUSTED is required for all types, when it's only use case is making PTR_TO_BTF_ID a bit stronger, while all other types are trusted by default. Hence, just drop the two instances which do not occur in the verifier for now to avoid reader confusion. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20230221200646.2500777-5-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Kumar Kartikeya Dwivedi
|
0a09a2f933 |
bpf: Annotate data races in bpf_local_storage
There are a few cases where hlist_node is checked to be unhashed without holding the lock protecting its modification. In this case, one must use hlist_unhashed_lockless to avoid load tearing and KCSAN reports. Fix this by using lockless variant in places not protected by the lock. Since this is not prompted by any actual KCSAN reports but only from code review, I have not included a fixes tag. Cc: Martin KaFai Lau <martin.lau@kernel.org> Cc: KP Singh <kpsingh@kernel.org> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20230221200646.2500777-4-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Eduard Zingerman
|
6715df8d5d |
bpf: Allow reads from uninit stack
This commits updates the following functions to allow reads from
uninitialized stack locations when env->allow_uninit_stack option is
enabled:
- check_stack_read_fixed_off()
- check_stack_range_initialized(), called from:
- check_stack_read_var_off()
- check_helper_mem_access()
Such change allows to relax logic in stacksafe() to treat STACK_MISC
and STACK_INVALID in a same way and make the following stack slot
configurations equivalent:
| Cached state | Current state |
| stack slot | stack slot |
|------------------+------------------|
| STACK_INVALID or | STACK_INVALID or |
| STACK_MISC | STACK_SPILL or |
| | STACK_MISC or |
| | STACK_ZERO or |
| | STACK_DYNPTR |
This leads to significant verification speed gains (see below).
The idea was suggested by Andrii Nakryiko [1] and initial patch was
created by Alexei Starovoitov [2].
Currently the env->allow_uninit_stack is allowed for programs loaded
by users with CAP_PERFMON or CAP_SYS_ADMIN capabilities.
A number of test cases from verifier/*.c were expecting uninitialized
stack access to be an error. These test cases were updated to execute
in unprivileged mode (thus preserving the tests).
The test progs/test_global_func10.c expected "invalid indirect read
from stack" error message because of the access to uninitialized
memory region. This error is no longer possible in privileged mode.
The test is updated to provoke an error "invalid indirect access to
stack" because of access to invalid stack address (such error is not
verified by progs/test_global_func*.c series of tests).
The following tests had to be removed because these can't be made
unprivileged:
- verifier/sock.c:
- "sk_storage_get(map, skb->sk, &stack_value, 1): partially init
stack_value"
BPF_PROG_TYPE_SCHED_CLS programs are not executed in unprivileged mode.
- verifier/var_off.c:
- "indirect variable-offset stack access, max_off+size > max_initialized"
- "indirect variable-offset stack access, uninitialized"
These tests verify that access to uninitialized stack values is
detected when stack offset is not a constant. However, variable
stack access is prohibited in unprivileged mode, thus these tests
are no longer valid.
* * *
Here is veristat log comparing this patch with current master on a
set of selftest binaries listed in tools/testing/selftests/bpf/veristat.cfg
and cilium BPF binaries (see [3]):
$ ./veristat -e file,prog,states -C -f 'states_pct<-30' master.log current.log
File Program States (A) States (B) States (DIFF)
-------------------------- -------------------------- ---------- ---------- ----------------
bpf_host.o tail_handle_ipv6_from_host 349 244 -105 (-30.09%)
bpf_host.o tail_handle_nat_fwd_ipv4 1320 895 -425 (-32.20%)
bpf_lxc.o tail_handle_nat_fwd_ipv4 1320 895 -425 (-32.20%)
bpf_sock.o cil_sock4_connect 70 48 -22 (-31.43%)
bpf_sock.o cil_sock4_sendmsg 68 46 -22 (-32.35%)
bpf_xdp.o tail_handle_nat_fwd_ipv4 1554 803 -751 (-48.33%)
bpf_xdp.o tail_lb_ipv4 6457 2473 -3984 (-61.70%)
bpf_xdp.o tail_lb_ipv6 7249 3908 -3341 (-46.09%)
pyperf600_bpf_loop.bpf.o on_event 287 145 -142 (-49.48%)
strobemeta.bpf.o on_event 15915 4772 -11143 (-70.02%)
strobemeta_nounroll2.bpf.o on_event 17087 3820 -13267 (-77.64%)
xdp_synproxy_kern.bpf.o syncookie_tc 21271 6635 -14636 (-68.81%)
xdp_synproxy_kern.bpf.o syncookie_xdp 23122 6024 -17098 (-73.95%)
-------------------------- -------------------------- ---------- ---------- ----------------
Note: I limited selection by states_pct<-30%.
Inspection of differences in pyperf600_bpf_loop behavior shows that
the following patch for the test removes almost all differences:
- a/tools/testing/selftests/bpf/progs/pyperf.h
+ b/tools/testing/selftests/bpf/progs/pyperf.h
@ -266,8 +266,8 @ int __on_event(struct bpf_raw_tracepoint_args *ctx)
}
if (event->pthread_match || !pidData->use_tls) {
- void* frame_ptr;
- FrameData frame;
+ void* frame_ptr = 0;
+ FrameData frame = {};
Symbol sym = {};
int cur_cpu = bpf_get_smp_processor_id();
W/o this patch the difference comes from the following pattern
(for different variables):
static bool get_frame_data(... FrameData *frame ...)
{
...
bpf_probe_read_user(&frame->f_code, ...);
if (!frame->f_code)
return false;
...
bpf_probe_read_user(&frame->co_name, ...);
if (frame->co_name)
...;
}
int __on_event(struct bpf_raw_tracepoint_args *ctx)
{
FrameData frame;
...
get_frame_data(... &frame ...) // indirectly via a bpf_loop & callback
...
}
SEC("raw_tracepoint/kfree_skb")
int on_event(struct bpf_raw_tracepoint_args* ctx)
{
...
ret |= __on_event(ctx);
ret |= __on_event(ctx);
...
}
With regards to value `frame->co_name` the following is important:
- Because of the conditional `if (!frame->f_code)` each call to
__on_event() produces two states, one with `frame->co_name` marked
as STACK_MISC, another with it as is (and marked STACK_INVALID on a
first call).
- The call to bpf_probe_read_user() does not mark stack slots
corresponding to `&frame->co_name` as REG_LIVE_WRITTEN but it marks
these slots as BPF_MISC, this happens because of the following loop
in the check_helper_call():
for (i = 0; i < meta.access_size; i++) {
err = check_mem_access(env, insn_idx, meta.regno, i, BPF_B,
BPF_WRITE, -1, false);
if (err)
return err;
}
Note the size of the write, it is a one byte write for each byte
touched by a helper. The BPF_B write does not lead to write marks
for the target stack slot.
- Which means that w/o this patch when second __on_event() call is
verified `if (frame->co_name)` will propagate read marks first to a
stack slot with STACK_MISC marks and second to a stack slot with
STACK_INVALID marks and these states would be considered different.
[1] https://lore.kernel.org/bpf/CAEf4BzY3e+ZuC6HUa8dCiUovQRg2SzEk7M-dSkqNZyn=xEmnPA@mail.gmail.com/
[2] https://lore.kernel.org/bpf/CAADnVQKs2i1iuZ5SUGuJtxWVfGYR9kDgYKhq3rNV+kBLQCu7rA@mail.gmail.com/
[3] git@github.com:anakryiko/cilium.git
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Co-developed-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230219200427.606541-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Linus Torvalds
|
f3dd0c5337 |
bpf: add missing header file include
Commit |
||
|
Linus Torvalds
|
5b7c4cabbb |
Networking changes for 6.3.
Core
----
- Add dedicated kmem_cache for typical/small skb->head, avoid having
to access struct page at kfree time, and improve memory use.
- Introduce sysctl to set default RPS configuration for new netdevs.
- Define Netlink protocol specification format which can be used
to describe messages used by each family and auto-generate parsers.
Add tools for generating kernel data structures and uAPI headers.
- Expose all net/core sysctls inside netns.
- Remove 4s sleep in netpoll if carrier is instantly detected on boot.
- Add configurable limit of MDB entries per port, and port-vlan.
- Continue populating drop reasons throughout the stack.
- Retire a handful of legacy Qdiscs and classifiers.
Protocols
---------
- Support IPv4 big TCP (TSO frames larger than 64kB).
- Add IP_LOCAL_PORT_RANGE socket option, to control local port range
on socket by socket basis.
- Track and report in procfs number of MPTCP sockets used.
- Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP
path manager.
- IPv6: don't check net.ipv6.route.max_size and rely on garbage
collection to free memory (similarly to IPv4).
- Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).
- ICMP: add per-rate limit counters.
- Add support for user scanning requests in ieee802154.
- Remove static WEP support.
- Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
reporting.
- WiFi 7 EHT channel puncturing support (client & AP).
BPF
---
- Add a rbtree data structure following the "next-gen data structure"
precedent set by recently added linked list, that is, by using
kfunc + kptr instead of adding a new BPF map type.
- Expose XDP hints via kfuncs with initial support for RX hash and
timestamp metadata.
- Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key
to better support decap on GRE tunnel devices not operating
in collect metadata.
- Improve x86 JIT's codegen for PROBE_MEM runtime error checks.
- Remove the need for trace_printk_lock for bpf_trace_printk
and bpf_trace_vprintk helpers.
- Extend libbpf's bpf_tracing.h support for tracing arguments of
kprobes/uprobes and syscall as a special case.
- Significantly reduce the search time for module symbols
by livepatch and BPF.
- Enable cpumasks to be used as kptrs, which is useful for tracing
programs tracking which tasks end up running on which CPUs in
different time intervals.
- Add support for BPF trampoline on s390x and riscv64.
- Add capability to export the XDP features supported by the NIC.
- Add __bpf_kfunc tag for marking kernel functions as kfuncs.
- Add cgroup.memory=nobpf kernel parameter option to disable BPF
memory accounting for container environments.
Netfilter
---------
- Remove the CLUSTERIP target. It has been marked as obsolete
for years, and we still have WARN splats wrt. races of
the out-of-band /proc interface installed by this target.
- Add 'destroy' commands to nf_tables. They are identical to
the existing 'delete' commands, but do not return an error if
the referenced object (set, chain, rule...) did not exist.
Driver API
----------
- Improve cpumask_local_spread() locality to help NICs set the right
IRQ affinity on AMD platforms.
- Separate C22 and C45 MDIO bus transactions more clearly.
- Introduce new DCB table to control DSCP rewrite on egress.
- Support configuration of Physical Layer Collision Avoidance (PLCA)
Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
shared medium Ethernet.
- Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
preemption of low priority frames by high priority frames.
- Add support for controlling MACSec offload using netlink SET.
- Rework devlink instance refcounts to allow registration and
de-registration under the instance lock. Split the code into multiple
files, drop some of the unnecessarily granular locks and factor out
common parts of netlink operation handling.
- Add TX frame aggregation parameters (for USB drivers).
- Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
messages with notifications for debug.
- Allow offloading of UDP NEW connections via act_ct.
- Add support for per action HW stats in TC.
- Support hardware miss to TC action (continue processing in SW from
a specific point in the action chain).
- Warn if old Wireless Extension user space interface is used with
modern cfg80211/mac80211 drivers. Do not support Wireless Extensions
for Wi-Fi 7 devices at all. Everyone should switch to using nl80211
interface instead.
- Improve the CAN bit timing configuration. Use extack to return error
messages directly to user space, update the SJW handling, including
the definition of a new default value that will benefit CAN-FD
controllers, by increasing their oscillator tolerance.
New hardware / drivers
----------------------
- Ethernet:
- nVidia BlueField-3 support (control traffic driver)
- Ethernet support for imx93 SoCs
- Motorcomm yt8531 gigabit Ethernet PHY
- onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
- Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
- Amlogic gxl MDIO mux
- WiFi:
- RealTek RTL8188EU (rtl8xxxu)
- Qualcomm Wi-Fi 7 devices (ath12k)
- CAN:
- Renesas R-Car V4H
Drivers
-------
- Bluetooth:
- Set Per Platform Antenna Gain (PPAG) for Intel controllers.
- Ethernet NICs:
- Intel (1G, igc):
- support TSN / Qbv / packet scheduling features of i226 model
- Intel (100G, ice):
- use GNSS subsystem instead of TTY
- multi-buffer XDP support
- extend support for GPIO pins to E823 devices
- nVidia/Mellanox:
- update the shared buffer configuration on PFC commands
- implement PTP adjphase function for HW offset control
- TC support for Geneve and GRE with VF tunnel offload
- more efficient crypto key management method
- multi-port eswitch support
- Netronome/Corigine:
- add DCB IEEE support
- support IPsec offloading for NFP3800
- Freescale/NXP (enetc):
- enetc: support XDP_REDIRECT for XDP non-linear buffers
- enetc: improve reconfig, avoid link flap and waiting for idle
- enetc: support MAC Merge layer
- Other NICs:
- sfc/ef100: add basic devlink support for ef100
- ionic: rx_push mode operation (writing descriptors via MMIO)
- bnxt: use the auxiliary bus abstraction for RDMA
- r8169: disable ASPM and reset bus in case of tx timeout
- cpsw: support QSGMII mode for J721e CPSW9G
- cpts: support pulse-per-second output
- ngbe: add an mdio bus driver
- usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
- r8152: handle devices with FW with NCM support
- amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
- virtio-net: support multi buffer XDP
- virtio/vsock: replace virtio_vsock_pkt with sk_buff
- tsnep: XDP support
- Ethernet high-speed switches:
- nVidia/Mellanox (mlxsw):
- add support for latency TLV (in FW control messages)
- Microchip (sparx5):
- separate explicit and implicit traffic forwarding rules, make
the implicit rules always active
- add support for egress DSCP rewrite
- IS0 VCAP support (Ingress Classification)
- IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.)
- ES2 VCAP support (Egress Access Control)
- support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1)
- Ethernet embedded switches:
- Marvell (mv88e6xxx):
- add MAB (port auth) offload support
- enable PTP receive for mv88e6390
- NXP (ocelot):
- support MAC Merge layer
- support for the the vsc7512 internal copper phys
- Microchip:
- lan9303: convert to PHYLINK
- lan966x: support TC flower filter statistics
- lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
- lan937x: support Credit Based Shaper configuration
- ksz9477: support Energy Efficient Ethernet
- other:
- qca8k: convert to regmap read/write API, use bulk operations
- rswitch: Improve TX timestamp accuracy
- Intel WiFi (iwlwifi):
- EHT (Wi-Fi 7) rate reporting
- STEP equalizer support: transfer some STEP (connection to radio
on platforms with integrated wifi) related parameters from the
BIOS to the firmware.
- Qualcomm 802.11ax WiFi (ath11k):
- IPQ5018 support
- Fine Timing Measurement (FTM) responder role support
- channel 177 support
- MediaTek WiFi (mt76):
- per-PHY LED support
- mt7996: EHT (Wi-Fi 7) support
- Wireless Ethernet Dispatch (WED) reset support
- switch to using page pool allocator
- RealTek WiFi (rtw89):
- support new version of Bluetooth co-existance
- Mobile:
- rmnet: support TX aggregation.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Jakub Kicinski:
"Core:
- Add dedicated kmem_cache for typical/small skb->head, avoid having
to access struct page at kfree time, and improve memory use.
- Introduce sysctl to set default RPS configuration for new netdevs.
- Define Netlink protocol specification format which can be used to
describe messages used by each family and auto-generate parsers.
Add tools for generating kernel data structures and uAPI headers.
- Expose all net/core sysctls inside netns.
- Remove 4s sleep in netpoll if carrier is instantly detected on
boot.
- Add configurable limit of MDB entries per port, and port-vlan.
- Continue populating drop reasons throughout the stack.
- Retire a handful of legacy Qdiscs and classifiers.
Protocols:
- Support IPv4 big TCP (TSO frames larger than 64kB).
- Add IP_LOCAL_PORT_RANGE socket option, to control local port range
on socket by socket basis.
- Track and report in procfs number of MPTCP sockets used.
- Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
manager.
- IPv6: don't check net.ipv6.route.max_size and rely on garbage
collection to free memory (similarly to IPv4).
- Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).
- ICMP: add per-rate limit counters.
- Add support for user scanning requests in ieee802154.
- Remove static WEP support.
- Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
reporting.
- WiFi 7 EHT channel puncturing support (client & AP).
BPF:
- Add a rbtree data structure following the "next-gen data structure"
precedent set by recently added linked list, that is, by using
kfunc + kptr instead of adding a new BPF map type.
- Expose XDP hints via kfuncs with initial support for RX hash and
timestamp metadata.
- Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
better support decap on GRE tunnel devices not operating in collect
metadata.
- Improve x86 JIT's codegen for PROBE_MEM runtime error checks.
- Remove the need for trace_printk_lock for bpf_trace_printk and
bpf_trace_vprintk helpers.
- Extend libbpf's bpf_tracing.h support for tracing arguments of
kprobes/uprobes and syscall as a special case.
- Significantly reduce the search time for module symbols by
livepatch and BPF.
- Enable cpumasks to be used as kptrs, which is useful for tracing
programs tracking which tasks end up running on which CPUs in
different time intervals.
- Add support for BPF trampoline on s390x and riscv64.
- Add capability to export the XDP features supported by the NIC.
- Add __bpf_kfunc tag for marking kernel functions as kfuncs.
- Add cgroup.memory=nobpf kernel parameter option to disable BPF
memory accounting for container environments.
Netfilter:
- Remove the CLUSTERIP target. It has been marked as obsolete for
years, and we still have WARN splats wrt races of the out-of-band
/proc interface installed by this target.
- Add 'destroy' commands to nf_tables. They are identical to the
existing 'delete' commands, but do not return an error if the
referenced object (set, chain, rule...) did not exist.
Driver API:
- Improve cpumask_local_spread() locality to help NICs set the right
IRQ affinity on AMD platforms.
- Separate C22 and C45 MDIO bus transactions more clearly.
- Introduce new DCB table to control DSCP rewrite on egress.
- Support configuration of Physical Layer Collision Avoidance (PLCA)
Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
shared medium Ethernet.
- Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
preemption of low priority frames by high priority frames.
- Add support for controlling MACSec offload using netlink SET.
- Rework devlink instance refcounts to allow registration and
de-registration under the instance lock. Split the code into
multiple files, drop some of the unnecessarily granular locks and
factor out common parts of netlink operation handling.
- Add TX frame aggregation parameters (for USB drivers).
- Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
messages with notifications for debug.
- Allow offloading of UDP NEW connections via act_ct.
- Add support for per action HW stats in TC.
- Support hardware miss to TC action (continue processing in SW from
a specific point in the action chain).
- Warn if old Wireless Extension user space interface is used with
modern cfg80211/mac80211 drivers. Do not support Wireless
Extensions for Wi-Fi 7 devices at all. Everyone should switch to
using nl80211 interface instead.
- Improve the CAN bit timing configuration. Use extack to return
error messages directly to user space, update the SJW handling,
including the definition of a new default value that will benefit
CAN-FD controllers, by increasing their oscillator tolerance.
New hardware / drivers:
- Ethernet:
- nVidia BlueField-3 support (control traffic driver)
- Ethernet support for imx93 SoCs
- Motorcomm yt8531 gigabit Ethernet PHY
- onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
- Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
- Amlogic gxl MDIO mux
- WiFi:
- RealTek RTL8188EU (rtl8xxxu)
- Qualcomm Wi-Fi 7 devices (ath12k)
- CAN:
- Renesas R-Car V4H
Drivers:
- Bluetooth:
- Set Per Platform Antenna Gain (PPAG) for Intel controllers.
- Ethernet NICs:
- Intel (1G, igc):
- support TSN / Qbv / packet scheduling features of i226 model
- Intel (100G, ice):
- use GNSS subsystem instead of TTY
- multi-buffer XDP support
- extend support for GPIO pins to E823 devices
- nVidia/Mellanox:
- update the shared buffer configuration on PFC commands
- implement PTP adjphase function for HW offset control
- TC support for Geneve and GRE with VF tunnel offload
- more efficient crypto key management method
- multi-port eswitch support
- Netronome/Corigine:
- add DCB IEEE support
- support IPsec offloading for NFP3800
- Freescale/NXP (enetc):
- support XDP_REDIRECT for XDP non-linear buffers
- improve reconfig, avoid link flap and waiting for idle
- support MAC Merge layer
- Other NICs:
- sfc/ef100: add basic devlink support for ef100
- ionic: rx_push mode operation (writing descriptors via MMIO)
- bnxt: use the auxiliary bus abstraction for RDMA
- r8169: disable ASPM and reset bus in case of tx timeout
- cpsw: support QSGMII mode for J721e CPSW9G
- cpts: support pulse-per-second output
- ngbe: add an mdio bus driver
- usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
- r8152: handle devices with FW with NCM support
- amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
- virtio-net: support multi buffer XDP
- virtio/vsock: replace virtio_vsock_pkt with sk_buff
- tsnep: XDP support
- Ethernet high-speed switches:
- nVidia/Mellanox (mlxsw):
- add support for latency TLV (in FW control messages)
- Microchip (sparx5):
- separate explicit and implicit traffic forwarding rules, make
the implicit rules always active
- add support for egress DSCP rewrite
- IS0 VCAP support (Ingress Classification)
- IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
etc.)
- ES2 VCAP support (Egress Access Control)
- support for Per-Stream Filtering and Policing (802.1Q,
8.6.5.1)
- Ethernet embedded switches:
- Marvell (mv88e6xxx):
- add MAB (port auth) offload support
- enable PTP receive for mv88e6390
- NXP (ocelot):
- support MAC Merge layer
- support for the the vsc7512 internal copper phys
- Microchip:
- lan9303: convert to PHYLINK
- lan966x: support TC flower filter statistics
- lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
- lan937x: support Credit Based Shaper configuration
- ksz9477: support Energy Efficient Ethernet
- other:
- qca8k: convert to regmap read/write API, use bulk operations
- rswitch: Improve TX timestamp accuracy
- Intel WiFi (iwlwifi):
- EHT (Wi-Fi 7) rate reporting
- STEP equalizer support: transfer some STEP (connection to radio
on platforms with integrated wifi) related parameters from the
BIOS to the firmware.
- Qualcomm 802.11ax WiFi (ath11k):
- IPQ5018 support
- Fine Timing Measurement (FTM) responder role support
- channel 177 support
- MediaTek WiFi (mt76):
- per-PHY LED support
- mt7996: EHT (Wi-Fi 7) support
- Wireless Ethernet Dispatch (WED) reset support
- switch to using page pool allocator
- RealTek WiFi (rtw89):
- support new version of Bluetooth co-existance
- Mobile:
- rmnet: support TX aggregation"
* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
page_pool: add a comment explaining the fragment counter usage
net: ethtool: fix __ethtool_dev_mm_supported() implementation
ethtool: pse-pd: Fix double word in comments
xsk: add linux/vmalloc.h to xsk.c
sefltests: netdevsim: wait for devlink instance after netns removal
selftest: fib_tests: Always cleanup before exit
net/mlx5e: Align IPsec ASO result memory to be as required by hardware
net/mlx5e: TC, Set CT miss to the specific ct action instance
net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
net/mlx5: Refactor tc miss handling to a single function
net/mlx5: Kconfig: Make tc offload depend on tc skb extension
net/sched: flower: Support hardware miss to tc action
net/sched: flower: Move filter handle initialization earlier
net/sched: cls_api: Support hardware miss to tc action
net/sched: Rename user cookie and act cookie
sfc: fix builds without CONFIG_RTC_LIB
sfc: clean up some inconsistent indentings
net/mlx4_en: Introduce flexible array to silence overflow warning
net: lan966x: Fix possible deadlock inside PTP
net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
...
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Dave Hansen
|
74e19ef0ff |
uaccess: Add speculation barrier to copy_from_user()
The results of "access_ok()" can be mis-speculated. The result is that you can end speculatively: if (access_ok(from, size)) // Right here even for bad from/size combinations. On first glance, it would be ideal to just add a speculation barrier to "access_ok()" so that its results can never be mis-speculated. But there are lots of system calls just doing access_ok() via "copy_to_user()" and friends (example: fstat() and friends). Those are generally not problematic because they do not _consume_ data from userspace other than the pointer. They are also very quick and common system calls that should not be needlessly slowed down. "copy_from_user()" on the other hand uses a user-controller pointer and is frequently followed up with code that might affect caches. Take something like this: if (!copy_from_user(&kernelvar, uptr, size)) do_something_with(kernelvar); If userspace passes in an evil 'uptr' that *actually* points to a kernel addresses, and then do_something_with() has cache (or other) side-effects, it could allow userspace to infer kernel data values. Add a barrier to the common copy_from_user() code to prevent mis-speculated values which happen after the copy. Also add a stub for architectures that do not define barrier_nospec(). This makes the macro usable in generic code. Since the barrier is now usable in generic code, the x86 #ifdef in the BPF code can also go away. Reported-by: Jordy Zomer <jordyzomer@google.com> Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Daniel Borkmann <daniel@iogearbox.net> # BPF bits Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
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Linus Torvalds
|
05e6295f7b |
fs.idmapped.v6.3
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Merge tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping
Pull vfs idmapping updates from Christian Brauner:
- Last cycle we introduced the dedicated struct mnt_idmap type for
mount idmapping and the required infrastucture in
|
||
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Andrii Nakryiko
|
d384dce281 |
bpf: Fix global subprog context argument resolution logic
KPROBE program's user-facing context type is defined as typedef
bpf_user_pt_regs_t. This leads to a problem when trying to passing
kprobe/uprobe/usdt context argument into global subprog, as kernel
always strip away mods and typedefs of user-supplied type, but takes
expected type from bpf_ctx_convert as is, which causes mismatch.
Current way to work around this is to define a fake struct with the same
name as expected typedef:
struct bpf_user_pt_regs_t {};
__noinline my_global_subprog(struct bpf_user_pt_regs_t *ctx) { ... }
This patch fixes the issue by resolving expected type, if it's not
a struct. It still leaves the above work-around working for backwards
compatibility.
Fixes:
|
||
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Hou Tao
|
997849c4b9 |
bpf: Zeroing allocated object from slab in bpf memory allocator
Currently the freed element in bpf memory allocator may be immediately
reused, for htab map the reuse will reinitialize special fields in map
value (e.g., bpf_spin_lock), but lookup procedure may still access
these special fields, and it may lead to hard-lockup as shown below:
NMI backtrace for cpu 16
CPU: 16 PID: 2574 Comm: htab.bin Tainted: G L 6.1.0+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
RIP: 0010:queued_spin_lock_slowpath+0x283/0x2c0
......
Call Trace:
<TASK>
copy_map_value_locked+0xb7/0x170
bpf_map_copy_value+0x113/0x3c0
__sys_bpf+0x1c67/0x2780
__x64_sys_bpf+0x1c/0x20
do_syscall_64+0x30/0x60
entry_SYSCALL_64_after_hwframe+0x46/0xb0
......
</TASK>
For htab map, just like the preallocated case, these is no need to
initialize these special fields in map value again once these fields
have been initialized. For preallocated htab map, these fields are
initialized through __GFP_ZERO in bpf_map_area_alloc(), so do the
similar thing for non-preallocated htab in bpf memory allocator. And
there is no need to use __GFP_ZERO for per-cpu bpf memory allocator,
because __alloc_percpu_gfp() does it implicitly.
Fixes:
|
||
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Eduard Zingerman
|
31ff213512 |
bpf: BPF_ST with variable offset should preserve STACK_ZERO marks
BPF_STX instruction preserves STACK_ZERO marks for variable offset
writes in situations like below:
*(u64*)(r10 - 8) = 0 ; STACK_ZERO marks for fp[-8]
r0 = random(-7, -1) ; some random number in range of [-7, -1]
r0 += r10 ; r0 is now a variable offset pointer to stack
r1 = 0
*(u8*)(r0) = r1 ; BPF_STX writing zero, STACK_ZERO mark for
; fp[-8] is preserved
This commit updates verifier.c:check_stack_write_var_off() to process
BPF_ST in a similar manner, e.g. the following example:
*(u64*)(r10 - 8) = 0 ; STACK_ZERO marks for fp[-8]
r0 = random(-7, -1) ; some random number in range of [-7, -1]
r0 += r10 ; r0 is now variable offset pointer to stack
*(u8*)(r0) = 0 ; BPF_ST writing zero, STACK_ZERO mark for
; fp[-8] is preserved
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230214232030.1502829-4-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Eduard Zingerman
|
ecdf985d76 |
bpf: track immediate values written to stack by BPF_ST instruction
For aligned stack writes using BPF_ST instruction track stored values
in a same way BPF_STX is handled, e.g. make sure that the following
commands produce similar verifier knowledge:
fp[-8] = 42; r1 = 42;
fp[-8] = r1;
This covers two cases:
- non-null values written to stack are stored as spill of fake
registers;
- null values written to stack are stored as STACK_ZERO marks.
Previously both cases above used STACK_MISC marks instead.
Some verifier test cases relied on the old logic to obtain STACK_MISC
marks for some stack values. These test cases are updated in the same
commit to avoid failures during bisect.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230214232030.1502829-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Dave Marchevsky
|
a40d363243 |
bpf: Special verifier handling for bpf_rbtree_{remove, first}
Newly-added bpf_rbtree_{remove,first} kfuncs have some special properties
that require handling in the verifier:
* both bpf_rbtree_remove and bpf_rbtree_first return the type containing
the bpf_rb_node field, with the offset set to that field's offset,
instead of a struct bpf_rb_node *
* mark_reg_graph_node helper added in previous patch generalizes
this logic, use it
* bpf_rbtree_remove's node input is a node that's been inserted
in the tree - a non-owning reference.
* bpf_rbtree_remove must invalidate non-owning references in order to
avoid aliasing issue. Use previously-added
invalidate_non_owning_refs helper to mark this function as a
non-owning ref invalidation point.
* Unlike other functions, which convert one of their input arg regs to
non-owning reference, bpf_rbtree_first takes no arguments and just
returns a non-owning reference (possibly null)
* For now verifier logic for this is special-cased instead of
adding new kfunc flag.
This patch, along with the previous one, complete special verifier
handling for all rbtree API functions added in this series.
With functional verifier handling of rbtree_remove, under current
non-owning reference scheme, a node type with both bpf_{list,rb}_node
fields could cause the verifier to accept programs which remove such
nodes from collections they haven't been added to.
In order to prevent this, this patch adds a check to btf_parse_fields
which rejects structs with both bpf_{list,rb}_node fields. This is a
temporary measure that can be removed after "collection identity"
followup. See comment added in btf_parse_fields. A linked_list BTF test
exercising the new check is added in this patch as well.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230214004017.2534011-6-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Dave Marchevsky
|
5d92ddc3de |
bpf: Add callback validation to kfunc verifier logic
Some BPF helpers take a callback function which the helper calls. For
each helper that takes such a callback, there's a special call to
__check_func_call with a callback-state-setting callback that sets up
verifier bpf_func_state for the callback's frame.
kfuncs don't have any of this infrastructure yet, so let's add it in
this patch, following existing helper pattern as much as possible. To
validate functionality of this added plumbing, this patch adds
callback handling for the bpf_rbtree_add kfunc and hopes to lay
groundwork for future graph datastructure callbacks.
In the "general plumbing" category we have:
* check_kfunc_call doing callback verification right before clearing
CALLER_SAVED_REGS, exactly like check_helper_call
* recognition of func_ptr BTF types in kfunc args as
KF_ARG_PTR_TO_CALLBACK + propagation of subprogno for this arg type
In the "rbtree_add / graph datastructure-specific plumbing" category:
* Since bpf_rbtree_add must be called while the spin_lock associated
with the tree is held, don't complain when callback's func_state
doesn't unlock it by frame exit
* Mark rbtree_add callback's args with ref_set_non_owning
to prevent rbtree api functions from being called in the callback.
Semantically this makes sense, as less() takes no ownership of its
args when determining which comes first.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230214004017.2534011-5-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Dave Marchevsky
|
cd6791b4b6 |
bpf: Add support for bpf_rb_root and bpf_rb_node in kfunc args
Now that we find bpf_rb_root and bpf_rb_node in structs, let's give args
that contain those types special classification and properly handle
these types when checking kfunc args.
"Properly handling" these types largely requires generalizing similar
handling for bpf_list_{head,node}, with little new logic added in this
patch.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230214004017.2534011-4-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Dave Marchevsky
|
bd1279ae8a |
bpf: Add bpf_rbtree_{add,remove,first} kfuncs
This patch adds implementations of bpf_rbtree_{add,remove,first}
and teaches verifier about their BTF_IDs as well as those of
bpf_rb_{root,node}.
All three kfuncs have some nonstandard component to their verification
that needs to be addressed in future patches before programs can
properly use them:
* bpf_rbtree_add: Takes 'less' callback, need to verify it
* bpf_rbtree_first: Returns ptr_to_node_type(off=rb_node_off) instead
of ptr_to_rb_node(off=0). Return value ref is
non-owning.
* bpf_rbtree_remove: Returns ptr_to_node_type(off=rb_node_off) instead
of ptr_to_rb_node(off=0). 2nd arg (node) is a
non-owning reference.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230214004017.2534011-3-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Dave Marchevsky
|
9c395c1b99 |
bpf: Add basic bpf_rb_{root,node} support
This patch adds special BPF_RB_{ROOT,NODE} btf_field_types similar to
BPF_LIST_{HEAD,NODE}, adds the necessary plumbing to detect the new
types, and adds bpf_rb_root_free function for freeing bpf_rb_root in
map_values.
structs bpf_rb_root and bpf_rb_node are opaque types meant to
obscure structs rb_root_cached rb_node, respectively.
btf_struct_access will prevent BPF programs from touching these special
fields automatically now that they're recognized.
btf_check_and_fixup_fields now groups list_head and rb_root together as
"graph root" fields and {list,rb}_node as "graph node", and does same
ownership cycle checking as before. Note that this function does _not_
prevent ownership type mixups (e.g. rb_root owning list_node) - that's
handled by btf_parse_graph_root.
After this patch, a bpf program can have a struct bpf_rb_root in a
map_value, but not add anything to nor do anything useful with it.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230214004017.2534011-2-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
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|
Dave Marchevsky
|
6a3cd3318f |
bpf: Migrate release_on_unlock logic to non-owning ref semantics
This patch introduces non-owning reference semantics to the verifier,
specifically linked_list API kfunc handling. release_on_unlock logic for
refs is refactored - with small functional changes - to implement these
semantics, and bpf_list_push_{front,back} are migrated to use them.
When a list node is pushed to a list, the program still has a pointer to
the node:
n = bpf_obj_new(typeof(*n));
bpf_spin_lock(&l);
bpf_list_push_back(&l, n);
/* n still points to the just-added node */
bpf_spin_unlock(&l);
What the verifier considers n to be after the push, and thus what can be
done with n, are changed by this patch.
Common properties both before/after this patch:
* After push, n is only a valid reference to the node until end of
critical section
* After push, n cannot be pushed to any list
* After push, the program can read the node's fields using n
Before:
* After push, n retains the ref_obj_id which it received on
bpf_obj_new, but the associated bpf_reference_state's
release_on_unlock field is set to true
* release_on_unlock field and associated logic is used to implement
"n is only a valid ref until end of critical section"
* After push, n cannot be written to, the node must be removed from
the list before writing to its fields
* After push, n is marked PTR_UNTRUSTED
After:
* After push, n's ref is released and ref_obj_id set to 0. NON_OWN_REF
type flag is added to reg's type, indicating that it's a non-owning
reference.
* NON_OWN_REF flag and logic is used to implement "n is only a
valid ref until end of critical section"
* n can be written to (except for special fields e.g. bpf_list_node,
timer, ...)
Summary of specific implementation changes to achieve the above:
* release_on_unlock field, ref_set_release_on_unlock helper, and logic
to "release on unlock" based on that field are removed
* The anonymous active_lock struct used by bpf_verifier_state is
pulled out into a named struct bpf_active_lock.
* NON_OWN_REF type flag is introduced along with verifier logic
changes to handle non-owning refs
* Helpers are added to use NON_OWN_REF flag to implement non-owning
ref semantics as described above
* invalidate_non_owning_refs - helper to clobber all non-owning refs
matching a particular bpf_active_lock identity. Replaces
release_on_unlock logic in process_spin_lock.
* ref_set_non_owning - set NON_OWN_REF type flag after doing some
sanity checking
* ref_convert_owning_non_owning - convert owning reference w/
specified ref_obj_id to non-owning references. Set NON_OWN_REF
flag for each reg with that ref_obj_id and 0-out its ref_obj_id
* Update linked_list selftests to account for minor semantic
differences introduced by this patch
* Writes to a release_on_unlock node ref are not allowed, while
writes to non-owning reference pointees are. As a result the
linked_list "write after push" failure tests are no longer scenarios
that should fail.
* The test##missing_lock##op and test##incorrect_lock##op
macro-generated failure tests need to have a valid node argument in
order to have the same error output as before. Otherwise
verification will fail early and the expected error output won't be seen.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230212092715.1422619-2-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
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|
Yafang Shao
|
bf39650824 |
bpf: allow to disable bpf prog memory accounting
We can simply disable the bpf prog memory accouting by not setting the GFP_ACCOUNT. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Link: https://lore.kernel.org/r/20230210154734.4416-5-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Yafang Shao
|
ee53cbfb1e |
bpf: allow to disable bpf map memory accounting
We can simply set root memcg as the map's memcg to disable bpf memory accounting. bpf_map_area_alloc is a little special as it gets the memcg from current rather than from the map, so we need to disable GFP_ACCOUNT specifically for it. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Link: https://lore.kernel.org/r/20230210154734.4416-4-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Yafang Shao
|
ddef81b5fd |
bpf: use bpf_map_kvcalloc in bpf_local_storage
Introduce new helper bpf_map_kvcalloc() for the memory allocation in bpf_local_storage(). Then the allocation will charge the memory from the map instead of from current, though currently they are the same thing as it is only used in map creation path now. By charging map's memory into the memcg from the map, it will be more clear. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Link: https://lore.kernel.org/r/20230210154734.4416-3-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Jakub Kicinski
|
de42873367 |
bpf-next-for-netdev
-----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTFp0I1jqZrAX+hPRXbK58LschIgwUCY+bZrwAKCRDbK58LschI gzi4AP4+TYo0jnSwwkrOoN9l4f5VO9X8osmj3CXfHBv7BGWVxAD/WnvA3TDZyaUd agIZTkRs6BHF9He8oROypARZxTeMLwM= =nO1C -----END PGP SIGNATURE----- Daniel Borkmann says: ==================== pull-request: bpf-next 2023-02-11 We've added 96 non-merge commits during the last 14 day(s) which contain a total of 152 files changed, 4884 insertions(+), 962 deletions(-). There is a minor conflict in drivers/net/ethernet/intel/ice/ice_main.c between commit |
||
|
Jakub Kicinski
|
025a785ff0 |
net: skbuff: drop the word head from skb cache
skbuff_head_cache is misnamed (perhaps for historical reasons?) because it does not hold heads. Head is the buffer which skb->data points to, and also where shinfo lives. struct sk_buff is a metadata structure, not the head. Eric recently added skb_small_head_cache (which allocates actual head buffers), let that serve as an excuse to finally clean this up :) Leave the user-space visible name intact, it could possibly be uAPI. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
||
|
Suren Baghdasaryan
|
1c71222e5f |
mm: replace vma->vm_flags direct modifications with modifier calls
Replace direct modifications to vma->vm_flags with calls to modifier functions to be able to track flag changes and to keep vma locking correctness. [akpm@linux-foundation.org: fix drivers/misc/open-dice.c, per Hyeonggon Yoo] Link: https://lkml.kernel.org/r/20230126193752.297968-5-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjun Roy <arjunroy@google.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: David Rientjes <rientjes@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Minchan Kim <minchan@google.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Peter Oskolkov <posk@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Punit Agrawal <punit.agrawal@bytedance.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Shakeel Butt <shakeelb@google.com> Cc: Soheil Hassas Yeganeh <soheil@google.com> Cc: Song Liu <songliubraving@fb.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Lorenzo Bianconi
|
b9d460c924 |
bpf: devmap: check XDP features in __xdp_enqueue routine
Check if the destination device implements ndo_xdp_xmit callback relying on NETDEV_XDP_ACT_NDO_XMIT flags. Moreover, check if the destination device supports XDP non-linear frame in __xdp_enqueue and is_valid_dst routines. This patch allows to perform XDP_REDIRECT on non-linear XDP buffers. Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Co-developed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/26a94c33520c0bfba021b3fbb2cb8c1e69bf53b8.1675245258.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Tobias Klauser
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158e5e9eea |
bpf: Drop always true do_idr_lock parameter to bpf_map_free_id
The do_idr_lock parameter to bpf_map_free_id was introduced by commit |