[PATCH 2/2] perf: arm_spe: Prevent overflow in PERF_IDX2OFF()

Leo Yan posted 2 patches 2 weeks ago
[PATCH 2/2] perf: arm_spe: Prevent overflow in PERF_IDX2OFF()
Posted by Leo Yan 2 weeks ago
Cast nr_pages to unsigned long to avoid overflow when handling large
AUX buffer sizes (>= 2 GiB).

Fixes: d5d9696b0380 ("drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension")
Signed-off-by: Leo Yan <leo.yan@arm.com>
---
 drivers/perf/arm_spe_pmu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/perf/arm_spe_pmu.c b/drivers/perf/arm_spe_pmu.c
index 369e77ad5f13ffb490bf8f128fee5180d1254bc6..8f14cb324e018349fbe19c5c20d92a9cdcfd2e73 100644
--- a/drivers/perf/arm_spe_pmu.c
+++ b/drivers/perf/arm_spe_pmu.c
@@ -97,7 +97,8 @@ struct arm_spe_pmu {
 #define to_spe_pmu(p) (container_of(p, struct arm_spe_pmu, pmu))
 
 /* Convert a free-running index from perf into an SPE buffer offset */
-#define PERF_IDX2OFF(idx, buf)	((idx) % ((buf)->nr_pages << PAGE_SHIFT))
+#define PERF_IDX2OFF(idx, buf) \
+	((idx) % ((unsigned long)(buf)->nr_pages << PAGE_SHIFT))
 
 /* Keep track of our dynamic hotplug state */
 static enum cpuhp_state arm_spe_pmu_online;

-- 
2.34.1