From patchwork Fri May 13 07:56:02 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wang Nan X-Patchwork-Id: 67726 Delivered-To: patch@linaro.org Received: by 10.140.92.199 with SMTP id b65csp135526qge; Fri, 13 May 2016 00:57:10 -0700 (PDT) X-Received: by 10.67.4.225 with SMTP id ch1mr20728126pad.120.1463126230869; Fri, 13 May 2016 00:57:10 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id q66si23008572pfb.190.2016.05.13.00.57.10; Fri, 13 May 2016 00:57:10 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752443AbcEMH4r (ORCPT + 29 others); Fri, 13 May 2016 03:56:47 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:28592 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751520AbcEMH4n (ORCPT ); Fri, 13 May 2016 03:56:43 -0400 Received: from 172.24.1.137 (EHLO szxeml433-hub.china.huawei.com) ([172.24.1.137]) by szxrg02-dlp.huawei.com (MOS 4.3.7-GA FastPath queued) with ESMTP id DHB52319; Fri, 13 May 2016 15:56:31 +0800 (CST) Received: from linux-4hy3.site (10.107.193.248) by szxeml433-hub.china.huawei.com (10.82.67.210) with Microsoft SMTP Server id 14.3.235.1; Fri, 13 May 2016 15:56:23 +0800 From: Wang Nan To: CC: , , Wang Nan , He Kuang , "Arnaldo Carvalho de Melo" , Jiri Olsa , Masami Hiramatsu , Namhyung Kim , "Zefan Li" , Subject: [PATCH 05/17] perf record: Prevent reading invalid data in record__mmap_read Date: Fri, 13 May 2016 07:56:02 +0000 Message-ID: <1463126174-119290-6-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1463126174-119290-1-git-send-email-wangnan0@huawei.com> References: <1463126174-119290-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.107.193.248] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020202.573588B0.0015, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 8b303c2fc43e29162e5fd88e21e43e19 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When record__mmap_read() requires data more than the size of ring buffer, drop those data to avoid accessing invalid memory. This can happen when reading from overwritable ring buffer, which should be avoided. However, check this for robustness. Signed-off-by: Wang Nan Signed-off-by: He Kuang Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com --- tools/perf/builtin-record.c | 8 ++++++++ 1 file changed, 8 insertions(+) -- 1.8.3.4 diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 21ef8a0..81c700d 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -40,6 +40,7 @@ #include #include #include +#include struct record { @@ -98,6 +99,13 @@ static int record__mmap_read(struct record *rec, int idx) rec->samples++; size = head - old; + if (size > (unsigned long)(md->mask) + 1) { + WARN_ONCE(1, "failed to keep up with mmap data. (warn only once)\n"); + + md->prev = head; + perf_evlist__mmap_consume(rec->evlist, idx); + return 0; + } if ((old & md->mask) + size != (head & md->mask)) { buf = &data[old & md->mask];