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| author | Kyle Huey <me@kylehuey.com> | 2024-04-11 18:50:18 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2024-04-12 11:49:50 +0200 |
| commit | c4fcc7d1f41532e878087c7c43f4cf247604d68b (patch) | |
| tree | 42d5d279844896a20d768199e71ca22cb84671a5 | |
| parent | 76f6d58845829e5d6ef55532e67a323e7d30c26e (diff) | |
| download | linux-stable-c4fcc7d1f41532e878087c7c43f4cf247604d68b.tar.gz linux-stable-c4fcc7d1f41532e878087c7c43f4cf247604d68b.tar.bz2 linux-stable-c4fcc7d1f41532e878087c7c43f4cf247604d68b.zip | |
perf/bpf: Allow a BPF program to suppress all sample side effects
Returning zero from a BPF program attached to a perf event already
suppresses any data output. Return early from __perf_event_overflow() in
this case so it will also suppress event_limit accounting, SIGTRAP
generation, and F_ASYNC signalling.
Signed-off-by: Kyle Huey <khuey@kylehuey.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240412015019.7060-7-khuey@kylehuey.com
| -rw-r--r-- | kernel/events/core.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index c6a6936183d5..2212670cbe9b 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9677,6 +9677,9 @@ static int __perf_event_overflow(struct perf_event *event, ret = __perf_event_account_interrupt(event, throttle); + if (event->prog && !bpf_overflow_handler(event, data, regs)) + return ret; + /* * XXX event_limit might not quite work as expected on inherited * events @@ -9726,8 +9729,7 @@ static int __perf_event_overflow(struct perf_event *event, irq_work_queue(&event->pending_irq); } - if (!(event->prog && !bpf_overflow_handler(event, data, regs))) - READ_ONCE(event->overflow_handler)(event, data, regs); + READ_ONCE(event->overflow_handler)(event, data, regs); if (*perf_event_fasync(event) && event->pending_kill) { event->pending_wakeup = 1; |