From patchwork Mon Jan 25 09:56:27 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wang Nan X-Patchwork-Id: 60315 Delivered-To: patch@linaro.org Received: by 10.112.130.2 with SMTP id oa2csp1259079lbb; Mon, 25 Jan 2016 02:09:02 -0800 (PST) X-Received: by 10.66.129.232 with SMTP id nz8mr24679212pab.102.1453716541868; Mon, 25 Jan 2016 02:09:01 -0800 (PST) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id bz9si4963792pab.187.2016.01.25.02.09.01; Mon, 25 Jan 2016 02:09:01 -0800 (PST) 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 S932402AbcAYKI7 (ORCPT + 30 others); Mon, 25 Jan 2016 05:08:59 -0500 Received: from szxga03-in.huawei.com ([119.145.14.66]:27235 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756629AbcAYJ6z (ORCPT ); Mon, 25 Jan 2016 04:58:55 -0500 Received: from 172.24.1.50 (EHLO szxeml428-hub.china.huawei.com) ([172.24.1.50]) by szxrg03-dlp.huawei.com (MOS 4.4.3-GA FastPath queued) with ESMTP id BVE53492; Mon, 25 Jan 2016 17:57:46 +0800 (CST) Received: from linux-4hy3.site (10.107.193.248) by szxeml428-hub.china.huawei.com (10.82.67.183) with Microsoft SMTP Server id 14.3.235.1; Mon, 25 Jan 2016 17:57:40 +0800 From: Wang Nan To: Alexei Starovoitov , Arnaldo Carvalho de Melo CC: Brendan Gregg , Daniel Borkmann , "David S. Miller" , He Kuang , Jiri Olsa , Li Zefan , Masami Hiramatsu , Namhyung Kim , Peter Zijlstra , , Will Deacon , , Wang Nan Subject: [PATCH 40/54] perf record: Prevent reading invalid data in record__mmap_read Date: Mon, 25 Jan 2016 09:56:27 +0000 Message-ID: <1453715801-7732-41-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1453715801-7732-1-git-send-email-wangnan0@huawei.com> References: <1453715801-7732-1-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=0001.0A020203.56A5F19B.00CB, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 4d752a0c0ff21208546d54faab27f33f 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 9265948..0a4f3ec 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -37,6 +37,7 @@ #include #include #include +#include struct record { @@ -95,6 +96,13 @@ 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];