perf: Fix incorrect copy_from_user() usage
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: John Blackwood<john.blackwood@ccur.com>
Signed-off-by: Joe Korty <joe.korty@ccur.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100928220311.GA18145@tsunami.ccur.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index db5b560..b98bed3 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -2202,15 +2202,13 @@
static int perf_event_period(struct perf_event *event, u64 __user *arg)
{
struct perf_event_context *ctx = event->ctx;
- unsigned long size;
int ret = 0;
u64 value;
if (!event->attr.sample_period)
return -EINVAL;
- size = copy_from_user(&value, arg, sizeof(value));
- if (size != sizeof(value))
+ if (copy_from_user(&value, arg, sizeof(value)))
return -EFAULT;
if (!value)