Patch "perf/x86/intel: Fix constraint access" has been added to the 4.1-stable tree

This is a note to let you know that I've just added the patch titled

perf/x86/intel: Fix constraint access

to the 4.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
perf-x86-intel-fix-constraint-access.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Peter Zijlstra <[email protected]>
Date: Thu, 10 Sep 2015 11:58:27 +0200
Subject: perf/x86/intel: Fix constraint access

From: Peter Zijlstra <[email protected]>

commit ebfb4988f0378e2ac3b4a0aa1ea20d724293f392 upstream.

Sasha reported that we can get here with .idx==-1, and cpuc->event_constraints unallocated.

---
 arch/x86/kernel/cpu/perf_event_intel.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

@@ -2098,9 +2098,12 @@ static struct event_constraint *
 intel_get_event_constraints(struct cpu_hw_events *cpuc, int idx,
 			    struct perf_event *event)
 {
-	struct event_constraint *c1 = cpuc->event_constraint[idx];
+	struct event_constraint *c1 = NULL;
 	struct event_constraint *c2;
 
+	if (idx >= 0) /* fake does < 0 */
+		c1 = cpuc->event_constraint[idx];
+
 	/*
 	 * first time only
 	 * - static constraint: no change across incremental scheduling calls

Patches currently in stable-queue which might be from [email protected] are

queue-4.1/time-fix-timekeeping_freqadjust-s-incorrect-use-of-abs-instead-of-abs64.patch queue-4.1/perf-x86-intel-fix-constraint-access.patch queue-4.1/sched-access-local-runqueue-directly-in-single_task_running.patch queue-4.1/perf-fix-aux-buffer-refcounting.patch