[RESEND] tools/mm: Use calloc and check the memory allocation failure

[Zhu Jun]

Replace malloc with calloc and add null pointer check
in case of allocation failure.

Signed-off-by: Zhu Jun <zhujun2@xxxxxxxxxxxxxxxxxxxx>
---
 tools/mm/page_owner_sort.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/mm/page_owner_sort.c b/tools/mm/page_owner_sort.c
index e1f264444342..8c78265cef67 100644
--- a/tools/mm/page_owner_sort.c
+++ b/tools/mm/page_owner_sort.c
@@ -368,9 +368,10 @@ static __u64 get_ts_nsec(char *buf)
 
 static char *get_comm(char *buf)
 {
-	char *comm_str = malloc(TASK_COMM_LEN);
+	char *comm_str = calloc(TASK_COMM_LEN, sizeof(char));
 
-	memset(comm_str, 0, TASK_COMM_LEN);
+	if (!comm_str)
+		return NULL;
 
 	search_pattern(&comm_pattern, comm_str, buf);
 	errno = 0;
-- 
2.17.1