Re: [tip: perf/core] perf: Fix irq work dereferencing garbage

[Frederic Weisbecker <frederic@kernel.org>]

Le Thu, May 08, 2025 at 10:34:29AM -0000, tip-bot2 for Frederic Weisbecker a écrit :
> The following commit has been merged into the perf/core branch of tip:
> 
> Commit-ID:     88d51e795539acd08bce028eff3aa78748b847a8
> Gitweb:        https://git.kernel.org/tip/88d51e795539acd08bce028eff3aa78748b847a8
> Author:        Frederic Weisbecker <frederic@kernel.org>
> AuthorDate:    Mon, 28 Apr 2025 13:11:47 +02:00
> Committer:     Peter Zijlstra <peterz@infradead.org>
> CommitterDate: Fri, 02 May 2025 12:40:40 +02:00
> 
> perf: Fix irq work dereferencing garbage
> 
> The following commit:
> 
> 	da916e96e2de ("perf: Make perf_pmu_unregister() useable")
> 
> has introduced two significant event's parent lifecycle changes:
> 
> 1) An event that has exited now has EVENT_TOMBSTONE as a parent.
>    This can result in a situation where the delayed wakeup irq_work can
>    accidentally dereference EVENT_TOMBSTONE on:
> 
> CPU 0                                          CPU 1

This is missing the most important (and boring) part of the changelog :-)

> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>

And I suspect some automatic check will also yell at some point at missing Sob.

Thanks.

-- 
Frederic Weisbecker
SUSE Labs