perf: Fix incorrect copy_from_user() usage (ad0cf347) · Commits · 戴 / test

perf events: repair incorrect use of copy_from_user This makes the perf_event_period() return 0 instead of -EFAULT on success. Signed-off-by:

Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20100928220311.GA18145@tsunami.ccur.com> Signed-off-by:

kernel/perf_event.c

+1 −3

Original line number	Original line	Diff line number	Diff line
	@@ -2202,15 +2202,13 @@ static void perf_event_for_each(struct perf_event *event,
	static int perf_event_period(struct perf_event event, u64 __user arg)		static int perf_event_period(struct perf_event event, u64 __user arg)
	{		{
	struct perf_event_context *ctx = event->ctx;		struct perf_event_context *ctx = event->ctx;
	unsigned long size;
	int ret = 0;		int ret = 0;
	u64 value;		u64 value;

	if (!event->attr.sample_period)		if (!event->attr.sample_period)
	return -EINVAL;		return -EINVAL;

	size = copy_from_user(&value, arg, sizeof(value));		if (copy_from_user(&value, arg, sizeof(value)))
	if (size != sizeof(value))
	return -EFAULT;		return -EFAULT;

	if (!value)		if (!value)