From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161869AbcFHIos (ORCPT ); Wed, 8 Jun 2016 04:44:48 -0400 Received: from terminus.zytor.com ([198.137.202.10]:54102 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161753AbcFHIoo (ORCPT ); Wed, 8 Jun 2016 04:44:44 -0400 Date: Wed, 8 Jun 2016 01:44:29 -0700 From: tip-bot for Wang Nan Message-ID: Cc: mhiramat@kernel.org, wangnan0@huawei.com, linux-kernel@vger.kernel.org, lizefan@huawei.com, tglx@linutronix.de, hpa@zytor.com, acme@redhat.com, mingo@kernel.org Reply-To: lizefan@huawei.com, hpa@zytor.com, tglx@linutronix.de, mingo@kernel.org, acme@redhat.com, mhiramat@kernel.org, linux-kernel@vger.kernel.org, wangnan0@huawei.com In-Reply-To: <1465271678-7392-1-git-send-email-wangnan0@huawei.com> References: <1465271678-7392-1-git-send-email-wangnan0@huawei.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf tools: Fix crash in build_id_cache__kallsyms_path() Git-Commit-ID: c58c49ac630979a285d574b3f72a528209515fb3 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: c58c49ac630979a285d574b3f72a528209515fb3 Gitweb: http://git.kernel.org/tip/c58c49ac630979a285d574b3f72a528209515fb3 Author: Wang Nan AuthorDate: Tue, 7 Jun 2016 03:54:38 +0000 Committer: Arnaldo Carvalho de Melo CommitDate: Tue, 7 Jun 2016 10:49:41 -0300 perf tools: Fix crash in build_id_cache__kallsyms_path() build_id_cache__kallsyms_path() accepts a string buffer but also allocs a buffer using asnprintf. Unfortunately, the its only user passes it a stack-allocated buffer. Freeing it causes crashes like this: $ perf script *** Error in `/home/wangnan/perf': free(): invalid pointer: 0x00007fffffff9630 *** ======= Backtrace: ========= lib64/libc.so.6(+0x6eeef)[0x7ffff5dbaeef] lib64/libc.so.6(+0x78cae)[0x7ffff5dc4cae] lib64/libc.so.6(+0x79987)[0x7ffff5dc5987] /home/w00229757/perf(build_id_cache__kallsyms_path+0x6b)[0x49681b] /home/w00229757/perf[0x4bdd40] /home/w00229757/perf(dso__load+0xa3a)[0x4c048a] /home/w00229757/perf(map__load+0x6f)[0x4d561f] /home/w00229757/perf(thread__find_addr_map+0x235)[0x49e935] /home/w00229757/perf(machine__resolve+0x7d)[0x49ec6d] /home/w00229757/perf[0x4555a8] /home/w00229757/perf[0x4d9507] /home/w00229757/perf[0x4d9e80] /home/w00229757/perf(ordered_events__flush+0x354)[0x4dd444] /home/w00229757/perf(perf_session__process_events+0x3d0)[0x4dc140] /home/w00229757/perf(cmd_script+0x12b0)[0x4592e0] /home/w00229757/perf[0x4911f1] /home/w00229757/perf(main+0x68f)[0x4352ef] /lib64/libc.so.6(__libc_start_main+0xf5)[0x7ffff5d6dbd5] /home/w00229757/perf[0x435415] ======= Memory map: ======== This patch simplifies build_id_cache__kallsyms_path(), not even considering allocating a string buffer, so never frees anything. Its caller should manage memory allocation. Signed-off-by: Wang Nan Cc: Masami Hiramatsu Cc: Zefan Li Cc: pi3orama@163.com Fixes: 01412261d994 ("perf buildid-cache: Use path/to/bin/buildid/elf instead of path/to/bin/buildid") Link: http://lkml.kernel.org/r/1465271678-7392-1-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/build-id.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c index 67f986c..20aef90 100644 --- a/tools/perf/util/build-id.c +++ b/tools/perf/util/build-id.c @@ -147,20 +147,17 @@ static int asnprintf(char **strp, size_t size, const char *fmt, ...) char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf, size_t size) { - bool is_alloc = !!bf; bool retry_old = true; - asnprintf(&bf, size, "%s/%s/%s/kallsyms", - buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); + snprintf(bf, size, "%s/%s/%s/kallsyms", + buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); retry: if (!access(bf, F_OK)) return bf; - if (is_alloc) - free(bf); if (retry_old) { /* Try old style kallsyms cache */ - asnprintf(&bf, size, "%s/%s/%s", - buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); + snprintf(bf, size, "%s/%s/%s", + buildid_dir, DSO__NAME_KALLSYMS, sbuild_id); retry_old = false; goto retry; }