From ebfb4988f0378e2ac3b4a0aa1ea20d724293f392 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 10 Sep 2015 11:58:27 +0200 Subject: [PATCH] perf/x86/intel: Fix constraint access Sasha reported that we can get here with .idx==-1, and cpuc->event_constraints unallocated. Suggested-by: Stephane Eranian Reported-by: Sasha Levin Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Fixes: b371b5943178 ("perf/x86: Fix event/group validation") Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event_intel.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index 3f124d553c5a..f41e4dc78119 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -2316,9 +2316,12 @@ 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 -- 2.20.1