From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnaldo Carvalho de Melo Subject: [PATCH 60/75] perf dso: Fix unchecked usage of strncpy() Date: Thu, 6 Dec 2018 18:25:47 -0300 Message-ID: <20181206212602.20474-61-acme@kernel.org> References: <20181206212602.20474-1-acme@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20181206212602.20474-1-acme@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Ingo Molnar Cc: Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Arnaldo Carvalho de Melo , Adrian Hunter , Jiri Olsa , Namhyung Kim List-Id: linux-perf-users.vger.kernel.org From: Arnaldo Carvalho de Melo The strncpy() function may leave the destination string buffer unterminated, better use strlcpy() that we have a __weak fallback implementation for systems without it. This fixes this warning on an Alpine Linux Edge system with gcc 8.2: In function 'decompress_kmodule', inlined from 'dso__decompress_kmodule_fd' at util/dso.c:305:9: util/dso.c:298:3: error: 'strncpy' destination unchanged after copying no bytes [-Werror=stringop-truncation] strncpy(pathname, tmpbuf, len); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ CC /tmp/build/perf/util/values.o CC /tmp/build/perf/util/debug.o cc1: all warnings being treated as errors Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Fixes: c9a8a6131fb6 ("perf tools: Move the temp file processing into decompress_kmodule") Link: https://lkml.kernel.org/n/tip-tl2hdxj64tt4k8btbi6a0ugw@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/dso.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c index bbed90e5d9bb..cee717a3794f 100644 --- a/tools/perf/util/dso.c +++ b/tools/perf/util/dso.c @@ -295,7 +295,7 @@ static int decompress_kmodule(struct dso *dso, const char *name, unlink(tmpbuf); if (pathname && (fd >= 0)) - strncpy(pathname, tmpbuf, len); + strlcpy(pathname, tmpbuf, len); return fd; } -- 2.19.2