[PATCH] arm64: perf: Convert snprintf to sysfs_emit

Use sysfs_emit instead of snprintf to avoid buf overrun,because in
sysfs_emit it strictly checks whether buf is null or buf whether
pagesize aligned, otherwise it returns an error.

Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
---
 arch/arm64/kernel/perf_event.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index f594957..44b6eda 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c

@@ -312,7 +312,7 @@ static ssize_t slots_show(struct device *dev, struct device_attribute *attr,
 	struct arm_pmu *cpu_pmu = container_of(pmu, struct arm_pmu, pmu);
 	u32 slots = cpu_pmu->reg_pmmir & ARMV8_PMU_SLOTS_MASK;
 
-	return snprintf(page, PAGE_SIZE, "0x%08x\n", slots);
+	return sysfs_emit(page, "0x%08x\n", slots);
 }
 
 static DEVICE_ATTR_RO(slots);

-- 
2.7.4

On Thu, 20 May 2021 15:59:45 +0800, Tian Tao wrote:

Use sysfs_emit instead of snprintf to avoid buf overrun,because in
sysfs_emit it strictly checks whether buf is null or buf whether
pagesize aligned, otherwise it returns an error.

Applied to will (for-next/perf), thanks!

[1/1] arm64: perf: Convert snprintf to sysfs_emit
      https://git.kernel.org/will/c/a5740e955540

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev