[PATCH 119/133] perf/arm: Fix armpmu_map_hw_event()

[Kamal Mostafa]

3.8.13.7 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stephen Boyd <sboyd at codeaurora.org>

commit b88a2595b6d8aedbd275c07dfa784657b4f757eb upstream.

Fix constraint check in armpmu_map_hw_event().

Reported-and-tested-by: Vince Weaver <vincent.weaver at maine.edu>
Signed-off-by: Ingo Molnar <mingo at kernel.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 arch/arm/kernel/perf_event.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 5da31bb..0a29456 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -53,7 +53,12 @@ armpmu_map_cache_event(const unsigned (*cache_map)
 static int
 armpmu_map_hw_event(const unsigned (*event_map)[PERF_COUNT_HW_MAX], u64 config)
 {
-	int mapping = (*event_map)[config];
+	int mapping;
+
+	if (config >= PERF_COUNT_HW_MAX)
+		return -ENOENT;
+
+	mapping = (*event_map)[config];
 	return mapping == HW_OP_UNSUPPORTED ? -ENOENT : mapping;
 }
 
-- 
1.8.1.2