From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752281AbeCZO0I (ORCPT ); Mon, 26 Mar 2018 10:26:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:53188 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751750AbeCZO0H (ORCPT ); Mon, 26 Mar 2018 10:26:07 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 114652172B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=acme@kernel.org Date: Mon, 26 Mar 2018 11:26:04 -0300 From: Arnaldo Carvalho de Melo To: kan.liang@linux.intel.com Cc: mingo@redhat.com, linux-kernel@vger.kernel.org, jolsa@kernel.org, namhyung@kernel.org, wangnan0@huawei.com Subject: Re: [PATCH] perf mmap: Fix accessing unmapped mmap in perf_mmap__read_done() Message-ID: <20180326142604.GE18897@kernel.org> References: <1522071729-16776-1-git-send-email-kan.liang@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1522071729-16776-1-git-send-email-kan.liang@linux.intel.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Mon, Mar 26, 2018 at 09:42:09AM -0400, kan.liang@linux.intel.com escreveu: > From: Kan Liang > > There is segmentation fault when running perf trace. For example, > [root@jouet e]# perf trace -e *chdir -o /tmp/bla perf report > --ignore-vmlinux -i ../perf.data > > The perf_mmap__consume() could unmap the mmap. It needs to check the > refcnt in perf_mmap__read_done(). > > Fixes: ee023de05f35 ("perf mmap: Introduce perf_mmap__read_done()") > Reported-by: Arnaldo Carvalho de Melo > Signed-off-by: Kan Liang Seems insuficient: [root@jouet ~]# perf trace -e *chdir -o /tmp/bla perf report --ignore-vmlinux perf: Segmentation fault Obtained 9 stack frames. perf(sighandler_dump_stack+0x3e) [0x4fe31e] /lib64/libc.so.6(+0x346df) [0x7fc0c3ced6df] perf(perf_mmap__read_init+0x26) [0x4ccd06] perf(cmd_trace+0x1bf6) [0x47bb76] perf() [0x4a824e] perf() [0x4a8550] perf(main+0x331) [0x42bef1] /lib64/libc.so.6(__libc_start_main+0xe9) [0x7fc0c3cd9f29] perf(_start+0x29) [0x42c319] Segmentation fault (core dumped) [root@jouet ~]# - Arnaldo