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Steven Rostedt 6d15f08e6d tracing: Do not register unsupported perf events
commit ef7f38df890f5dcd2ae62f8dbde191d72f3bebae upstream.

Synthetic events currently do not have a function to register perf events.
This leads to calling the tracepoint register functions with a NULL
function pointer which triggers:

 ------------[ cut here ]------------
 WARNING: kernel/tracepoint.c:175 at tracepoint_add_func+0x357/0x370, CPU#2: perf/2272
 Modules linked in: kvm_intel kvm irqbypass
 CPU: 2 UID: 0 PID: 2272 Comm: perf Not tainted 6.18.0-ftest-11964-ge022764176fc-dirty #323 PREEMPTLAZY
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.17.0-debian-1.17.0-1 04/01/2014
 RIP: 0010:tracepoint_add_func+0x357/0x370
 Code: 28 9c e8 4c 0b f5 ff eb 0f 4c 89 f7 48 c7 c6 80 4d 28 9c e8 ab 89 f4 ff 31 c0 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc <0f> 0b 49 c7 c6 ea ff ff ff e9 ee fe ff ff 0f 0b e9 f9 fe ff ff 0f
 RSP: 0018:ffffabc0c44d3c40 EFLAGS: 00010246
 RAX: 0000000000000001 RBX: ffff9380aa9e4060 RCX: 0000000000000000
 RDX: 000000000000000a RSI: ffffffff9e1d4a98 RDI: ffff937fcf5fd6c8
 RBP: 0000000000000001 R08: 0000000000000007 R09: ffff937fcf5fc780
 R10: 0000000000000003 R11: ffffffff9c193910 R12: 000000000000000a
 R13: ffffffff9e1e5888 R14: 0000000000000000 R15: ffffabc0c44d3c78
 FS:  00007f6202f5f340(0000) GS:ffff93819f00f000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 000055d3162281a8 CR3: 0000000106a56003 CR4: 0000000000172ef0
 Call Trace:
  <TASK>
  tracepoint_probe_register+0x5d/0x90
  synth_event_reg+0x3c/0x60
  perf_trace_event_init+0x204/0x340
  perf_trace_init+0x85/0xd0
  perf_tp_event_init+0x2e/0x50
  perf_try_init_event+0x6f/0x230
  ? perf_event_alloc+0x4bb/0xdc0
  perf_event_alloc+0x65a/0xdc0
  __se_sys_perf_event_open+0x290/0x9f0
  do_syscall_64+0x93/0x7b0
  ? entry_SYSCALL_64_after_hwframe+0x76/0x7e
  ? trace_hardirqs_off+0x53/0xc0
  entry_SYSCALL_64_after_hwframe+0x76/0x7e

Instead, have the code return -ENODEV, which doesn't warn and has perf
error out with:

 # perf record -e synthetic:futex_wait
Error:
The sys_perf_event_open() syscall returned with 19 (No such device) for event (synthetic:futex_wait).
"dmesg | grep -i perf" may provide additional information.

Ideally perf should support synthetic events, but for now just fix the
warning. The support can come later.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://patch.msgid.link/20251216182440.147e4453@gandalf.local.home
Fixes: 4b147936fa ("tracing: Add support for 'synthetic' events")
Reported-by: Ian Rogers <irogers@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-19 13:09:53 +01:00
arch KVM: nSVM: Clear exit_code_hi in VMCB when synthesizing nested VM-Exits 2026-01-19 13:09:53 +01:00
block block: rate-limit capacity change info log 2026-01-19 13:09:49 +01:00
certs
crypto crypto: asymmetric_keys - prevent overflow in asymmetric_key_generate_id 2026-01-19 13:09:24 +01:00
Documentation fs_context: drop the unused lsm_flags member 2026-01-19 13:09:38 +01:00
drivers parisc: Do not reprogram affinitiy on ASP chip 2026-01-19 13:09:52 +01:00
fs ocfs2: fix kernel BUG in ocfs2_find_victim_chain 2026-01-19 13:09:52 +01:00
include media: v4l2-mem2mem: Fix outdated documentation 2026-01-19 13:09:50 +01:00
init init: handle bootloader identifier in kernel parameters 2025-10-19 16:21:45 +02:00
io_uring io_uring: fix possible deadlock in io_register_iowq_max_workers() 2024-11-17 15:06:25 +01:00
ipc ipc: fix to protect IPCS lookups using RCU 2025-06-27 11:05:26 +01:00
kernel tracing: Do not register unsupported perf events 2026-01-19 13:09:53 +01:00
lib lib/vsprintf: Check pointer before dereferencing in time_and_date() 2026-01-19 13:09:29 +01:00
LICENSES
mm mm/secretmem: fix use-after-free race in fault handler 2025-12-07 06:09:32 +09:00
net libceph: make decode_pool() more resilient against corrupted osdmaps 2026-01-19 13:09:52 +01:00
samples samples: mei: Fix building on musl libc 2025-08-28 16:24:07 +02:00
scripts Makefile.compiler: replace cc-ifversion with compiler-specific macros 2025-12-07 06:09:32 +09:00
security KEYS: trusted: Fix a memory leak in tpm2_load_cmd 2026-01-19 13:09:48 +01:00
sound ALSA: usb-mixer: us16x08: validate meter packet indices 2026-01-19 13:09:46 +01:00
tools tools/testing/nvdimm: Use per-DIMM device handle 2026-01-19 13:09:52 +01:00
usr kbuild: hdrcheck: fix cross build with clang 2025-06-27 11:05:22 +01:00
virt KVM: Fix a data race on last_boosted_vcpu in kvm_vcpu_on_spin() 2024-10-22 15:40:41 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore Remove *.orig pattern from .gitignore 2024-10-17 15:11:10 +02:00
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS staging: rtl8712: Remove driver using deprecated API wext 2025-12-07 06:09:36 +09:00
Makefile Linux 5.15.197 2025-12-07 06:09:37 +09:00
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