4.9-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 7572588085a13d5db02bf159542189f52fdb507e ]
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_unit': util/header.c:3586:2: error: 'strncpy' output truncated before terminating nul copying as many bytes from a string as its length [-Werror=stringop-truncation] strncpy(ev->data, evsel->unit, size); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ util/header.c:3579:16: note: length computed here size_t size = strlen(evsel->unit); ^~~~~~~~~~~~~~~~~~~
Cc: Adrian Hunter adrian.hunter@intel.com Cc: Jiri Olsa jolsa@kernel.org Cc: Namhyung Kim namhyung@kernel.org Fixes: a6e5281780d1 ("perf tools: Add event_update event unit type") Link: https://lkml.kernel.org/n/tip-fiikh5nay70bv4zskw2aa858@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 ab36aa5585b4..a11f6760cce8 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -2988,7 +2988,7 @@ perf_event__synthesize_event_update_unit(struct perf_tool *tool, if (ev == NULL) return -ENOMEM;
- strncpy(ev->data, evsel->unit, size); + strlcpy(ev->data, evsel->unit, size + 1); err = process(tool, (union perf_event *)ev, NULL, NULL); free(ev); return err;