From ad0cf3478de8677f720ee06393b3147819568d6a Mon Sep 17 00:00:00 2001 From: John Blackwood <john.blackwood@ccur.com> Date: Tue, 28 Sep 2010 18:03:11 -0400 Subject: [PATCH] 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> --- kernel/perf_event.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/kernel/perf_event.c b/kernel/perf_event.c index db5b56064687..b98bed3d8182 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -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) { 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) -- 2.30.2