linux-kernel - [tip: perf/core] perf: Fix pmu_filter

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Date:   Wed, 05 Oct 2022 11:26:41 -0000
From:   "tip-bot2 for Peter Zijlstra" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Mark Rutland <mark.rutland@....com>,
        "Peter Zijlstra (Intel)" <peterz@...radead.org>, x86@...nel.org,
        linux-kernel@...r.kernel.org
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 <peterz@...radead.org>
AuthorDate:    Tue, 04 Oct 2022 11:03:47 +02:00
Committer:     Peter Zijlstra <peterz@...radead.org>
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 <mark.rutland@....com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
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