From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751944Ab2GYRlw (ORCPT ); Wed, 25 Jul 2012 13:41:52 -0400 Received: from casper.infradead.org ([85.118.1.10]:45482 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751793Ab2GYRlr (ORCPT ); Wed, 25 Jul 2012 13:41:47 -0400 From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, "Kirill A. Shutemov" , Paul Mackerras , Peter Zijlstra , Ulrich Drepper , Arnaldo Carvalho de Melo Subject: [PATCH 15/19] perf tools: use XSI-complaint version of strerror_r() instead of GNU-specific Date: Wed, 25 Jul 2012 14:41:30 -0300 Message-Id: <1343238094-12481-16-git-send-email-acme@infradead.org> X-Mailer: git-send-email 1.7.9.2.358.g22243 In-Reply-To: <1343238094-12481-1-git-send-email-acme@infradead.org> References: <1343238094-12481-1-git-send-email-acme@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="UTF-8" X-MIME-Error: demime acl condition: double headers (content-type, content-disposition or content-transfer-encoding) X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kirill A. Shutemov Perf uses GNU-specific version of strerror_r(). The GNU-specific strerror_r() returns a pointer to a string containing the error message. This may be either a pointer to a string that the function stores in buf, or a pointer to some (immutable) static string (in which case buf is unused). In glibc-2.16 GNU version was marked with attribute warn_unused_result. It triggers few warnings in perf: util/target.c: In function ‘perf_target__strerror’: util/target.c:114:13: error: ignoring return value of ‘strerror_r’, declared with attribute warn_unused_result [-Werror=unused-result] ui/browsers/hists.c: In function ‘hist_browser__dump’: ui/browsers/hists.c:981:13: error: ignoring return value of ‘strerror_r’, declared with attribute warn_unused_result [-Werror=unused-result] They are bugs. Let's fix strerror_r() usage. Signed-off-by: Kirill A. Shutemov Acked-by: Ulrich Drepper Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Ulrich Drepper Link: http://lkml.kernel.org/r/20120723210654.GA25248@shutemov.name [ committer note: s/assert/BUG_ON/g ] Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/ui/browsers/hists.c | 4 ++-- tools/perf/util/target.c | 11 ++++++++++- 2 files changed, 12 insertions(+), 3 deletions(-) diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c index 482f051..413bd62 100644 --- a/tools/perf/ui/browsers/hists.c +++ b/tools/perf/ui/browsers/hists.c @@ -978,8 +978,8 @@ static int hist_browser__dump(struct hist_browser *browser) fp = fopen(filename, "w"); if (fp == NULL) { char bf[64]; - strerror_r(errno, bf, sizeof(bf)); - ui_helpline__fpush("Couldn't write to %s: %s", filename, bf); + const char *err = strerror_r(errno, bf, sizeof(bf)); + ui_helpline__fpush("Couldn't write to %s: %s", filename, err); return -1; } diff --git a/tools/perf/util/target.c b/tools/perf/util/target.c index 1064d5b..3f59c49 100644 --- a/tools/perf/util/target.c +++ b/tools/perf/util/target.c @@ -110,8 +110,17 @@ int perf_target__strerror(struct perf_target *target, int errnum, int idx; const char *msg; + BUG_ON(buflen > 0); + if (errnum >= 0) { - strerror_r(errnum, buf, buflen); + const char *err = strerror_r(errnum, buf, buflen); + + if (err != buf) { + size_t len = strlen(err); + char *c = mempcpy(buf, err, min(buflen - 1, len)); + *c = '\0'; + } + return 0; } -- 1.7.1