perfcounter: Handle some IO return values

Building perfcounter tools raises the following warnings:

 builtin-record.c: In function ‘atexit_header’:
 builtin-record.c:464: erreur: ignoring return value of ‘pwrite’, declared with attribute warn_unused_result
 builtin-record.c: In function ‘__cmd_record’:
 builtin-record.c:503: erreur: ignoring return value of ‘read’, declared with attribute warn_unused_result

 builtin-report.c: In function ‘__cmd_report’:
 builtin-report.c:1403: erreur: ignoring return value of ‘read’, declared with attribute warn_unused_result

This patch handles these IO return values.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1245456100-5477-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 4 insertions, 1 deletions

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index de1b97845e9e..5eb5566f0c95 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -1400,7 +1400,10 @@ static int __cmd_report(void)
                 exit(0);
         }
 
-        read(input, &file_header, sizeof(file_header));
+        if (read(input, &file_header, sizeof(file_header)) == -1) {
+                perror("failed to read file headers");
+                exit(-1);
+        }
 
         if (sort__has_parent &&
             !(file_header.sample_type & PERF_SAMPLE_CALLCHAIN)) {