From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756466Ab0EaHVO (ORCPT ); Mon, 31 May 2010 03:21:14 -0400 Received: from hera.kernel.org ([140.211.167.34]:42512 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756432Ab0EaHVJ (ORCPT ); Mon, 31 May 2010 03:21:09 -0400 Date: Mon, 31 May 2010 07:20:44 GMT From: tip-bot for Frederic Weisbecker Cc: linux-kernel@vger.kernel.org, paulus@samba.org, acme@redhat.com, hpa@zytor.com, mingo@redhat.com, a.p.zijlstra@chello.nl, fweisbec@gmail.com, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, acme@redhat.com, paulus@samba.org, linux-kernel@vger.kernel.org, fweisbec@gmail.com, a.p.zijlstra@chello.nl, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <1274988898-5639-1-git-send-regression-fweisbec@gmail.com> References: <1274988898-5639-1-git-send-regression-fweisbec@gmail.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] perf_events: Fix unincremented buffer base on partial copy Message-ID: Git-Commit-ID: 74048f895fa8cbf8119b4999f1f44881a825f954 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Mon, 31 May 2010 07:20:45 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 74048f895fa8cbf8119b4999f1f44881a825f954 Gitweb: http://git.kernel.org/tip/74048f895fa8cbf8119b4999f1f44881a825f954 Author: Frederic Weisbecker AuthorDate: Thu, 27 May 2010 21:34:58 +0200 Committer: Ingo Molnar CommitDate: Mon, 31 May 2010 08:46:10 +0200 perf_events: Fix unincremented buffer base on partial copy If a sample size crosses to the next page boundary, the copy will be made in more than one step. However we forget to advance the source offset for the next copy, leading to unexpected double copies that completely mess up the traces. This fixes various kinds of bad traces that have irrelevant data inside, as an example: geany-4979 [001] 5758.077775: sched_switch: prev_comm=! prev_pid=121 prev_prio=0 prev_state=S|D|Z|X|x ==> next_comm= next_pid=7497072 next_prio=0 Signed-off-by: Frederic Weisbecker Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras Signed-off-by: Peter Zijlstra LKML-Reference: <1274988898-5639-1-git-send-regression-fweisbec@gmail.com> Signed-off-by: Ingo Molnar --- kernel/perf_event.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 42a0e91..858f56f 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -3064,6 +3064,7 @@ __always_inline void perf_output_copy(struct perf_output_handle *handle, len -= size; handle->addr += size; + buf += size; handle->size -= size; if (!handle->size) { struct perf_mmap_data *data = handle->data;