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Date:   Wed, 15 Nov 2023 10:58:17 +0100
From:   Peter Zijlstra <peterz@infradead.org>
To:     Namhyung Kim <namhyung@kernel.org>
Cc:     Jiri Olsa <olsajiri@gmail.com>, mingo@kernel.org,
        linux-kernel@vger.kernel.org, acme@kernel.org,
        mark.rutland@arm.com, alexander.shishkin@linux.intel.com,
        irogers@google.com, adrian.hunter@intel.com
Subject: Re: [PATCH 01/13] perf: Simplify perf_event_alloc() error path
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On Fri, Nov 03, 2023 at 12:50:19PM -0700, Namhyung Kim wrote:

> > > -err_pmu:
> > > -     if (is_cgroup_event(event))
> > > -             perf_detach_cgroup(event);
> > > -     if (event->destroy)
> > > -             event->destroy(event);
> > > -     module_put(pmu->module);
> 
> I'm afraid of this part.  If it failed at perf_init_event(), it might
> call event->destroy() already.  I saw you cleared event->pmu
> in the failure path.  Maybe we need the same thing for the
> event->destroy.

In that case event->destroy will not yet have been set, no?

And once it is set, we should call it.