4.14-stable review patch. If anyone has any objections, please let me know.
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From: Reinette Chatre reinette.chatre@intel.com
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/6486385d1f30336e9973b24c8c65f5079543d3d3.153737706... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- kernel/events/core.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3757,6 +3757,12 @@ int perf_event_read_local(struct perf_ev 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