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authorKyle Huey <[email protected]>2024-04-11 18:50:18 -0700
committerIngo Molnar <[email protected]>2024-04-12 11:49:50 +0200
commitc4fcc7d1f41532e878087c7c43f4cf247604d68b (patch)
tree42d5d279844896a20d768199e71ca22cb84671a5
parent76f6d58845829e5d6ef55532e67a323e7d30c26e (diff)
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 <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Acked-by: Song Liu <[email protected]> Acked-by: Jiri Olsa <[email protected]> Acked-by: Namhyung Kim <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/r/[email protected]
-rw-r--r--kernel/events/core.c6
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;