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authorReinette Chatre <reinette.chatre@intel.com>2018-09-19 10:29:06 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-10-13 09:27:21 +0200
commitab18409cf05f8e3d20ae3e5347f431947ecc397c (patch)
treeab2856b784e3335394d9838473fbd68fb5db4e6c
parent8e6a9240b1918c31a90e5d0a02c467ca68b160c6 (diff)
perf/core: Add sanity check to deal with pinned event failure
commit befb1b3c2703897c5b8ffb0044dc5d0e5f27c5d7 upstream. It is possible that a failure can occur during the scheduling of a pinned event. The initial portion of perf_event_read_local() contains the various error checks an event should pass before it can be considered valid. Ensure that the potential scheduling failure of a pinned event is checked for and have a credible error. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: fenghua.yu@intel.com Cc: tony.luck@intel.com Cc: acme@kernel.org Cc: gavin.hindman@intel.com Cc: jithu.joseph@intel.com Cc: dave.hansen@intel.com Cc: hpa@zytor.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/6486385d1f30336e9973b24c8c65f5079543d3d3.1537377064.git.reinette.chatre@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--kernel/events/core.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 812ebf1cbb87..4dbce29a9313 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3757,6 +3757,12 @@ int perf_event_read_local(struct perf_event *event, u64 *value)
goto out;
}
+ /* If this is a pinned event it must be running on this CPU */
+ if (event->attr.pinned && event->oncpu != smp_processor_id()) {
+ ret = -EBUSY;
+ goto out;
+ }
+
/*
* If the event is currently on this CPU, its either a per-task event,
* or local to this CPU. Furthermore it means its ACTIVE (otherwise