Re: [PATCH 1/1] perf/core: fix dangling cgroup pointer in cpuctx

[Yeoreum Yun <yeoreum.yun@arm.com>]

Hi Peter,

>
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -2120,18 +2120,6 @@ list_del_event(struct perf_event *event,
>  	if (event->group_leader == event)
>  		del_event_from_groups(event, ctx);
>
> -	/*
> -	 * If event was in error state, then keep it
> -	 * that way, otherwise bogus counts will be
> -	 * returned on read(). The only way to get out
> -	 * of error state is by explicit re-enabling
> -	 * of the event
> -	 */
> -	if (event->state > PERF_EVENT_STATE_OFF) {
> -		perf_cgroup_event_disable(event, ctx);
> -		perf_event_set_state(event, PERF_EVENT_STATE_OFF);
> -	}
> -
>  	ctx->generation++;
>  	event->pmu_ctx->nr_events--;

JFYI, this removal should be not included when you backport to v6.15
unless your patch backport together:
  commit 90661365021a ("perf Unify perf_event_free_task() / perf_evenet_exit_task_context()")

Thanks.

--
Sincerely,
Yeoreum Yun