From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754950Ab0I1W4U (ORCPT ); Tue, 28 Sep 2010 18:56:20 -0400 Received: from flusers.ccur.com ([173.221.59.2]:59758 "EHLO gamx.iccur.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752709Ab0I1W4T (ORCPT ); Tue, 28 Sep 2010 18:56:19 -0400 X-Greylist: delayed 3167 seconds by postgrey-1.27 at vger.kernel.org; Tue, 28 Sep 2010 18:56:19 EDT Date: Tue, 28 Sep 2010 18:03:11 -0400 From: Joe Korty To: mingo@elte.hu, a.p.zijlstra@chello.nl, john.blackwood@ccur.com Cc: linux-kernel@vger.kernel.org Subject: [PERF EVENTS] fix incorrect copy_from_user usage Message-ID: <20100928220311.GA18145@tsunami.ccur.com> Reply-To: Joe Korty MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-12-10) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org perf events: repair incorrect use of copy_from_user This makes the perf_event_period() return 0 instead of -EFAULT on success. Developed-by: John Blackwood Signed-off-by: Joe Korty Index: 2.6.36-rc5/kernel/perf_event.c =================================================================== --- 2.6.36-rc5.orig/kernel/perf_event.c 2010-09-28 17:38:16.000000000 -0400 +++ 2.6.36-rc5/kernel/perf_event.c 2010-09-28 17:48:10.000000000 -0400 @@ -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)