perf test mmap-thread-lookup: Initialize variable to suppress memory sanitizer warning

[ Upstream commit 4e4cf62b37da5ff45c904a3acf242ab29ed5881d ]

Running the 'perf test' command after building perf with a memory
sanitizer causes a warning that says:

  WARNING: MemorySanitizer: use-of-uninitialized-value... in mmap-thread-lookup.c

Initializing the go variable to 0 silences this harmless warning.

Committer warning:

This was harmless, just a simple test writing whatever was at that
sizeof(int) memory area just to signal another thread blocked reading
that file created with pipe(). Initialize it tho so that we don't get
this warning.

Signed-off-by: Numfor Mbiziwo-Tiapo <nums@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Drayton <mbd@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/20190702173716.181223-1-nums@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/tools/perf/tests/mmap-thread-lookup.c b/tools/perf/tests/mmap-thread-lookup.c
index 3c3f3e029e33bd77cb5b2d7284b6e3cb01735237..2ecb86876f1047baeefc4ff0f77db502fc09e449 100644 (file)
--- a/tools/perf/tests/mmap-thread-lookup.c
+++ b/tools/perf/tests/mmap-thread-lookup.c
@@ -52,7 +52,7 @@ static void *thread_fn(void *arg)
 {
        struct thread_data *td = arg;
        ssize_t ret;
-       int go;
+       int go = 0;
 
        if (thread_init(td))
                return NULL;