Commit 0ee288e6 authored by Jiri Olsa's avatar Jiri Olsa Committed by Andrii Nakryiko
Browse files

bpf,perf: Fix perf_event_detach_bpf_prog error handling 



Peter reported that perf_event_detach_bpf_prog might skip to release
the bpf program for -ENOENT error from bpf_prog_array_copy.

This can't happen because bpf program is stored in perf event and is
detached and released only when perf event is freed.

Let's drop the -ENOENT check and make sure the bpf program is released
in any case.

Fixes: 170a7e3e ("bpf: bpf_prog_array_copy() should return -ENOENT if exclude_prog not found")
Reported-by: default avatarPeter Zijlstra <peterz@infradead.org>
Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241023200352.3488610-1-jolsa@kernel.org

Closes: https://lore.kernel.org/lkml/20241022111638.GC16066@noisy.programming.kicks-ass.net/
parent 82bbe133

kernel/trace/bpf_trace.c

+0 −2
Original line number Diff line number Diff line
@@ -2216,8 +2216,6 @@ void perf_event_detach_bpf_prog(struct perf_event *event) 


	old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);

	ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array);

	if (ret == -ENOENT)

		goto unlock;

	if (ret < 0) {

		bpf_prog_array_delete_safe(old_array, event->prog);

	} else {