From patchwork Tue May 24 09:21:28 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wang Nan X-Patchwork-Id: 68461 Delivered-To: patch@linaro.org Received: by 10.140.92.199 with SMTP id b65csp527366qge; Tue, 24 May 2016 02:33:38 -0700 (PDT) X-Received: by 10.98.46.130 with SMTP id u124mr5135146pfu.134.1464082417941; Tue, 24 May 2016 02:33:37 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id pl16si3641566pab.116.2016.05.24.02.33.37; Tue, 24 May 2016 02:33:37 -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 S1754981AbcEXJdf (ORCPT + 30 others); Tue, 24 May 2016 05:33:35 -0400 Received: from szxga01-in.huawei.com ([58.251.152.64]:63646 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751714AbcEXJdd (ORCPT ); Tue, 24 May 2016 05:33:33 -0400 Received: from 172.24.1.136 (EHLO szxeml427-hub.china.huawei.com) ([172.24.1.136]) by szxrg01-dlp.huawei.com (MOS 4.3.7-GA FastPath queued) with ESMTP id DLC07264; Tue, 24 May 2016 17:33:04 +0800 (CST) Received: from linux-4hy3.site (10.107.193.248) by szxeml427-hub.china.huawei.com (10.82.67.182) with Microsoft SMTP Server id 14.3.235.1; Tue, 24 May 2016 17:21:32 +0800 From: Wang Nan To: CC: , , Wang Nan , Arnaldo Carvalho de Melo , Zefan Li Subject: [PATCH 2/2] perf record: Fix crash when kptr is restricted Date: Tue, 24 May 2016 09:21:28 +0000 Message-ID: <1464081688-167940-2-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1464081688-167940-1-git-send-email-wangnan0@huawei.com> References: <1464081688-167940-1-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=0001.0A090201.57441FD3.008B, 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: 215132c3989817ecad34476f90467a65 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Before this patch, a simple 'perf record' could fail if kptr_restrict is set to 1 (for normal user) or 2 (for root): # perf record ls WARNING: Kernel address maps (/proc/{kallsyms,modules}) are restricted, check /proc/sys/kernel/kptr_restrict. Samples in kernel functions may not be resolved if a suitable vmlinux file is not found in the buildid cache or in the vmlinux path. Samples in kernel modules won't be resolved at all. If some relocation was applied (e.g. kexec) symbols may be misresolved even with a suitable vmlinux or kallsyms file. Segmentation fault (core dumped) This patch skips perf_event__synthesize_kernel_mmap() when kptr is not available. Signed-off-by: Wang Nan Cc: Arnaldo Carvalho de Melo Cc: Zefan Li Cc: pi3orama@163.com --- tools/perf/util/event.c | 2 ++ 1 file changed, 2 insertions(+) -- 1.8.3.4 diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c index f6fcc68..9b141f1 100644 --- a/tools/perf/util/event.c +++ b/tools/perf/util/event.c @@ -673,6 +673,8 @@ int perf_event__synthesize_kernel_mmap(struct perf_tool *tool, int err; union perf_event *event; + if (symbol_conf.kptr_restrict) + return -1; if (map == NULL) return -1;