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| author | Reinette Chatre <reinette.chatre@intel.com> | 2018-09-19 10:29:06 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-09-28 22:44:53 +0200 |
| commit | befb1b3c2703897c5b8ffb0044dc5d0e5f27c5d7 (patch) | |
| tree | cad7af2717da74d35f2a6bdf23a590cc5522b3a7 | |
| parent | c307aaf3eb47969105887e4e8991ec00960a7ce8 (diff) | |
| download | lwn-befb1b3c2703897c5b8ffb0044dc5d0e5f27c5d7.tar.gz lwn-befb1b3c2703897c5b8ffb0044dc5d0e5f27c5d7.zip | |
perf/core: Add sanity check to deal with pinned event failure
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
| -rw-r--r-- | kernel/events/core.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index c80549bf82c6..dcb093e7b377 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3935,6 +3935,12 @@ 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 |