Messages in this thread Patch in this message | | | Date | Sat, 28 Mar 2015 11:24:13 +0100 | From | Ingo Molnar <> | Subject | [GIT PULL] perf fix |
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Linus,
Please pull the latest perf-urgent-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-urgent-for-linus
# HEAD: d525211f9d1be8b523ec7633f080f2116f5ea536 perf: Fix irq_work 'tail' recursion
A perf kernel side fix for a fuzzer triggered lockup.
Thanks,
Ingo
------------------> Peter Zijlstra (1): perf: Fix irq_work 'tail' recursion
kernel/events/core.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/kernel/events/core.c b/kernel/events/core.c index 453ef61311d4..2fabc0627165 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4574,6 +4574,13 @@ static void perf_pending_event(struct irq_work *entry) { struct perf_event *event = container_of(entry, struct perf_event, pending); + int rctx; + + rctx = perf_swevent_get_recursion_context(); + /* + * If we 'fail' here, that's OK, it means recursion is already disabled + * and we won't recurse 'further'. + */ if (event->pending_disable) { event->pending_disable = 0; @@ -4584,6 +4591,9 @@ static void perf_pending_event(struct irq_work *entry) event->pending_wakeup = 0; perf_event_wakeup(event); } + + if (rctx >= 0) + perf_swevent_put_recursion_context(rctx); } /*
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