From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933718Ab2J3NCv (ORCPT ); Tue, 30 Oct 2012 09:02:51 -0400 Received: from casper.infradead.org ([85.118.1.10]:55796 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932140Ab2J3NCt (ORCPT ); Tue, 30 Oct 2012 09:02:49 -0400 From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Namhyung Kim , Andrew Jones , Arnaldo Carvalho de Melo Subject: [PATCH 2/2] perf tools: Fix strbuf_addf() when the buffer needs to grow Date: Tue, 30 Oct 2012 11:02:39 -0200 Message-Id: <1351602159-10340-3-git-send-email-acme@infradead.org> X-Mailer: git-send-email 1.7.9.2.358.g22243 In-Reply-To: <1351602159-10340-1-git-send-email-acme@infradead.org> References: <1351602159-10340-1-git-send-email-acme@infradead.org> Content-Type: text/plain; charset="utf-8" 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: Namhyung Kim This was found during chasing down the header output regression. The strbuf_addf() was checking buffer length with a result of vscnprintf() which cannot be greater than that of strbuf_avail(). Since numa topology and pmu mapping info in header were converted to use strbuf, it sometimes caused uninteresting behaviors with the broken strbuf. Fix it by using vsnprintf() which returns desired output string length regardless of the available buffer size and grow the buffer if needed. Reported-by: Andrew Jones Tested-by: Andrew Jones Signed-off-by: Namhyung Kim Cc: Andrew Jones Link: http://lkml.kernel.org/r/1350999890-6920-2-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/strbuf.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/strbuf.c b/tools/perf/util/strbuf.c index 2eeb51b..cfa9068 100644 --- a/tools/perf/util/strbuf.c +++ b/tools/perf/util/strbuf.c @@ -90,17 +90,17 @@ void strbuf_addf(struct strbuf *sb, const char *fmt, ...) if (!strbuf_avail(sb)) strbuf_grow(sb, 64); va_start(ap, fmt); - len = vscnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap); + len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap); va_end(ap); if (len < 0) - die("your vscnprintf is broken"); + die("your vsnprintf is broken"); if (len > strbuf_avail(sb)) { strbuf_grow(sb, len); va_start(ap, fmt); - len = vscnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap); + len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap); va_end(ap); if (len > strbuf_avail(sb)) { - die("this should not happen, your snprintf is broken"); + die("this should not happen, your vsnprintf is broken"); } } strbuf_setlen(sb, sb->len + len); -- 1.7.9.2.358.g22243