From 5192bde7d98c99f2cd80225649e3c2e7493722f7 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Thu, 6 Dec 2018 11:09:46 -0300 Subject: [PATCH] perf header: Fix unchecked usage of strncpy() 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: util/header.c: In function 'perf_event__synthesize_event_update_name': util/header.c:3625:2: error: 'strncpy' output truncated before terminating nul copying as many bytes from a string as its length [-Werror=stringop-truncation] strncpy(ev->data, evsel->name, len); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ util/header.c:3618:15: note: length computed here size_t len = strlen(evsel->name); ^~~~~~~~~~~~~~~~~~~ Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Fixes: a6e5281780d1 ("perf tools: Add event_update event unit type") Link: https://lkml.kernel.org/n/tip-wycz66iy8dl2z3yifgqf894p@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/header.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index c87cfe6b7c96..1171d8400bf4 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -3622,7 +3622,7 @@ perf_event__synthesize_event_update_name(struct perf_tool *tool, if (ev == NULL) return -ENOMEM; - strncpy(ev->data, evsel->name, len); + strlcpy(ev->data, evsel->name, len + 1); err = process(tool, (union perf_event*) ev, NULL, NULL); free(ev); return err;