[PATCH v4 03/16] perf header: fail on write_padded error

[David Carrillo-Cisneros <davidcc@google.com>]

Do not proceed if write_padded error failed.

Also, add comments to remind that the return value of write_*
functions in util/header.c is an erro code and not the number
of bytes written.

Signed-off-by: David Carrillo-Cisneros <davidcc@google.com>
---
 tools/perf/util/header.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index a1b16da4b34d..68dcc70ca4ca 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -73,6 +73,7 @@ bool perf_header__has_feat(const struct perf_header *header, int feat)
 	return test_bit(feat, header->adds_features);
 }
 
+/* Return: 0 if succeded, -ERR if failed. */
 static int do_write(int fd, const void *buf, size_t size)
 {
 	while (size) {
@@ -88,6 +89,7 @@ static int do_write(int fd, const void *buf, size_t size)
 	return 0;
 }
 
+/* Return: 0 if succeded, -ERR if failed. */
 int write_padded(int fd, const void *bf, size_t count, size_t count_aligned)
 {
 	static const char zero_buf[NAME_ALIGN];
@@ -102,6 +104,7 @@ int write_padded(int fd, const void *bf, size_t count, size_t count_aligned)
 #define string_size(str)						\
 	(PERF_ALIGN((strlen(str) + 1), NAME_ALIGN) + sizeof(u32))
 
+/* Return: 0 if succeded, -ERR if failed. */
 static int do_write_string(int fd, const char *str)
 {
 	u32 len, olen;
@@ -3199,7 +3202,8 @@ int perf_event__synthesize_tracing_data(struct perf_tool *tool, int fd,
 	 */
 	tracing_data_put(tdata);
 
-	write_padded(fd, NULL, 0, padding);
+	if (write_padded(fd, NULL, 0, padding))
+		return -1;
 
 	return aligned_size;
 }
-- 
2.13.1.508.gb3defc5cc-goog