[PATCH 2/2] perfcounter: Handle pipe read failures in perf stat

[Frederic Weisbecker <fweisbec@gmail.com>]

Building builtin-stat.c reports the following errors:

cc1: warnings being treated as errors
builtin-stat.c: In function ‘run_perf_stat’:
builtin-stat.c:242: erreur: ignoring return value of ‘read’, declared with attribute warn_unused_result
builtin-stat.c:255: erreur: ignoring return value of ‘read’, declared with attribute warn_unused_result
make: *** [builtin-stat.o] Erreur 1

This patch handles the possible pipe read failures.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
---
 tools/perf/builtin-stat.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 01cc07e..27921a8 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -239,7 +239,8 @@ static int run_perf_stat(int argc __used, const char **argv)
 		/*
 		 * Wait until the parent tells us to go.
 		 */
-		read(go_pipe[0], &buf, 1);
+		if (read(go_pipe[0], &buf, 1) == -1)
+			perror("unable to read pipe");
 
 		execvp(argv[0], (char **)argv);
 
@@ -252,7 +253,8 @@ static int run_perf_stat(int argc __used, const char **argv)
 	 */
 	close(child_ready_pipe[1]);
 	close(go_pipe[0]);
-	read(child_ready_pipe[0], &buf, 1);
+	if (read(child_ready_pipe[0], &buf, 1) == -1)
+		perror("unable to read pipe");
 	close(child_ready_pipe[0]);
 
 	for (counter = 0; counter < nr_counters; counter++)
-- 
1.6.2.3