From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B9CDFC43441 for ; Sun, 11 Nov 2018 20:29:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 82B3720818 for ; Sun, 11 Nov 2018 20:29:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 82B3720818 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730504AbeKLFsW (ORCPT ); Mon, 12 Nov 2018 00:48:22 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:50332 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730392AbeKLFsT (ORCPT ); Mon, 12 Nov 2018 00:48:19 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gLvsf-0000lJ-9w; Sun, 11 Nov 2018 19:58:49 +0000 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gLvsa-0001t6-OI; Sun, 11 Nov 2018 19:58:44 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Wang Nan" , "Adrian Hunter" , "David Ahern" , "Arnaldo Carvalho de Melo" , "Jiri Olsa" , "Namhyung Kim" Date: Sun, 11 Nov 2018 19:49:05 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 355/366] perf thread_map: Use readdir() instead of deprecated readdir_r() In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.61-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Arnaldo Carvalho de Melo commit 3354cf71104de49326d19d2f9bdb1f66eea52ef4 upstream. The readdir() function is thread safe as long as just one thread uses a DIR, which is the case in thread_map, so, to avoid breaking the build with glibc-2.23.90 (upcoming 2.24), use it instead of readdir_r(). See: http://man7.org/linux/man-pages/man3/readdir.3.html "However, in modern implementations (including the glibc implementation), concurrent calls to readdir() that specify different directory streams are thread-safe. In cases where multiple threads must read from the same directory stream, using readdir() with external synchronization is still preferable to the use of the deprecated readdir_r(3) function." Noticed while building on a Fedora Rawhide docker container. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-del8h2a0f40z75j4r42l96l0@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- tools/perf/util/thread_map.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/tools/perf/util/thread_map.c +++ b/tools/perf/util/thread_map.c @@ -64,7 +64,7 @@ struct thread_map *thread_map__new_by_ui DIR *proc; int max_threads = 32, items, i; char path[256]; - struct dirent dirent, *next, **namelist = NULL; + struct dirent *dirent, **namelist = NULL; struct thread_map *threads = malloc(sizeof(*threads) + max_threads * sizeof(pid_t)); if (threads == NULL) @@ -76,16 +76,16 @@ struct thread_map *thread_map__new_by_ui threads->nr = 0; - while (!readdir_r(proc, &dirent, &next) && next) { + while ((dirent = readdir(proc)) != NULL) { char *end; bool grow = false; struct stat st; - pid_t pid = strtol(dirent.d_name, &end, 10); + pid_t pid = strtol(dirent->d_name, &end, 10); if (*end) /* only interested in proper numerical dirents */ continue; - snprintf(path, sizeof(path), "/proc/%s", dirent.d_name); + snprintf(path, sizeof(path), "/proc/%s", dirent->d_name); if (stat(path, &st) != 0) continue;