On 2025-10-07 11:45:52, Chris J Arges wrote:
From: Yeoreum Yun yeoreum.yun@arm.com
[ Upstream commit 3b7a34aebbdf2a4b7295205bf0c654294283ec82 ]
Commit a3c3c66670ce ("perf/core: Fix child_total_time_enabled accounting bug at task exit") moves the event->state update to before list_del_event(). This makes the event->state test in list_del_event() always false; never calling perf_cgroup_event_disable().
As a result, cpuctx->cgrp won't be cleared properly; causing havoc.
Cc: stable@vger.kernel.org # 6.6.x, 6.12.x Fixes: a3c3c66670ce ("perf/core: Fix child_total_time_enabled accounting bug at task exit") Signed-off-by: Chris J Arges carges@cloudflare.com
kernel/events/core.c | 21 ++++++--------------- 1 file changed, 6 insertions(+), 15 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c index 3cc06ffb60c1..6688660845d2 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2100,18 +2100,6 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx) 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--;
} @@ -2456,11 +2444,14 @@ __perf_remove_from_context(struct perf_event *event, */ if (flags & DETACH_EXIT) state = PERF_EVENT_STATE_EXIT;
- if (flags & DETACH_DEAD) {
event->pending_disable = 1;
- if (flags & DETACH_DEAD) state = PERF_EVENT_STATE_DEAD;
- }
- event_sched_out(event, ctx);
- if (event->state > PERF_EVENT_STATE_OFF)
perf_cgroup_event_disable(event, ctx);- perf_event_set_state(event, min(event->state, state)); if (flags & DETACH_GROUP) perf_group_detach(event);
-- 2.43.0
Hi, can this patch be applied to stable 6.6.x and 6.12.x?
Thanks, --chris