Subject: [tip: perf/core] perf: Fix pmu_filter_match()

The following commit has been merged into the perf/core branch of tip:

Commit-ID: 7be51cc1c68dfa180ef84e71bcb4204237bb5620
Gitweb: https://git.kernel.org/tip/7be51cc1c68dfa180ef84e71bcb4204237bb5620
Author: Peter Zijlstra <[email protected]>
AuthorDate: Tue, 04 Oct 2022 11:03:47 +02:00
Committer: Peter Zijlstra <[email protected]>
CommitterDate: Tue, 04 Oct 2022 13:32:09 +02:00

perf: Fix pmu_filter_match()

Mark reported that the new for_each_sibling_event() assertion triggers
in pmu_filter_match() -- which isn't always called with IRQs disabled
or ctx->mutex held.

Fixes: f3c0eba28704 ("perf: Add a few assertions")
Reported-by: Mark Rutland <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lkml.kernel.org/r/YvvJq2f/7eFVcnNy@FVFF77S0Q05N
---
kernel/events/core.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 49bc3b5..b981b87 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2226,16 +2226,22 @@ static inline int __pmu_filter_match(struct perf_event *event)
static inline int pmu_filter_match(struct perf_event *event)
{
struct perf_event *sibling;
+ unsigned long flags;
+ int ret = 1;

if (!__pmu_filter_match(event))
return 0;

+ local_irq_save(flags);
for_each_sibling_event(sibling, event) {
- if (!__pmu_filter_match(sibling))
- return 0;
+ if (!__pmu_filter_match(sibling)) {
+ ret = 0;
+ break;
+ }
}
+ local_irq_restore(flags);

- return 1;
+ return ret;
}

static inline int