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Message-ID: References: <20241022111638.GC16066@noisy.programming.kicks-ass.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241022111638.GC16066@noisy.programming.kicks-ass.net> On Tue, Oct 22, 2024 at 01:16:38PM +0200, Peter Zijlstra wrote: > Hi guys, > > Per commit 170a7e3ea070 ("bpf: bpf_prog_array_copy() should return > -ENOENT if exclude_prog not found") perf_event_detach_bpf_prog() can now > return without doing bpf_prog_put() and leaving event->prog set. > > This is very 'unexpected' behaviour. > > I'm not sure what's sane from the BPF side of things here, but leaving > event->prog set is really rather unexpected. > > Help? IIUC the ENOENT should never happen in perf event context, so not sure why we have that check.. also does not seem to be used from lirc code, Sean? perf_event_detach_bpf_prog is called when the event is being freed so I think we should always put and clear the event->prog jirka