On Thu, Dec 7, 2023 at 8:35 AM Kyle Huey <me@xxxxxxxxxxxx> wrote:
>
> Returning zero from a bpf program attached to a perf event already
> suppresses any data output. By clearing pending_kill, returning zero from a
> bpf program will effectively pretend the sample never happened for all
> userspace purposes.
>
> Signed-off-by: Kyle Huey <khuey@xxxxxxxxxxxx>
> ---
> kernel/events/core.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
LGTM
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index 19fddfc27a4a..6cda05a4969d 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -10421,8 +10421,10 @@ static void bpf_overflow_handler(struct perf_event *event,
> rcu_read_unlock();
> out:
> __this_cpu_dec(bpf_prog_active);
> - if (!ret)
> + if (!ret) {
> + event->pending_kill = 0;
> return;
> + }
>
> event->orig_overflow_handler(event, data, regs);
> }
> --
> 2.34.1
>
