[PATCH v2] tools/mm/page_owner_sort: free per-record allocations

[Yichong Chen]

add_list() allocates comm and txt for each page owner record, but the
cleanup path only frees the outer list array. This leaks both buffers for
every retained record.

Free discarded records during culling and free the retained records on
exit. Also unwind comm when allocating txt fails.

Signed-off-by: Yichong Chen <chenyichong@xxxxxxxxxxxxx>
---
Changes in v2:
- Wrap commit message lines to approximately 75 columns.
- Use "Yichong Chen" as the author name.

 tools/mm/page_owner_sort.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/tools/mm/page_owner_sort.c b/tools/mm/page_owner_sort.c
index e6954909401c..67a7fc6d9de2 100644
--- a/tools/mm/page_owner_sort.c
+++ b/tools/mm/page_owner_sort.c
@@ -372,6 +372,9 @@ static char *get_comm(char *buf)
 {
 	char *comm_str = malloc(TASK_COMM_LEN);
 
+	if (!comm_str)
+		return NULL;
+
 	memset(comm_str, 0, TASK_COMM_LEN);
 
 	search_pattern(&comm_pattern, comm_str, buf);
@@ -386,6 +389,12 @@ static char *get_comm(char *buf)
 	return comm_str;
 }
 
+static void free_block_list(struct block_list *block)
+{
+	free(block->comm);
+	free(block->txt);
+}
+
 static int get_arg_type(const char *arg)
 {
 	if (!strcmp(arg, "pid") || !strcmp(arg, "p"))
@@ -480,9 +489,15 @@ static bool add_list(char *buf, int len, char *ext_buf)
 	list[list_size].pid = get_pid(buf);
 	list[list_size].tgid = get_tgid(buf);
 	list[list_size].comm = get_comm(buf);
+	if (!list[list_size].comm) {
+		fprintf(stderr, "Out of memory\n");
+		return false;
+	}
 	list[list_size].txt = malloc(len+1);
 	if (!list[list_size].txt) {
 		fprintf(stderr, "Out of memory\n");
+		free(list[list_size].comm);
+		list[list_size].comm = NULL;
 		return false;
 	}
 	memcpy(list[list_size].txt, buf, len);
@@ -841,8 +856,10 @@ int main(int argc, char **argv)
 		} else {
 			list[count-1].num += list[i].num;
 			list[count-1].page_num += list[i].page_num;
+			free_block_list(&list[i]);
 		}
 	}
+	list_size = count;
 
 	qsort(list, count, sizeof(list[0]), compare_sort_condition);
 
@@ -876,8 +893,11 @@ int main(int argc, char **argv)
 		free(ext_buf);
 	if (buf)
 		free(buf);
-	if (list)
+	if (list) {
+		for (i = 0; i < list_size; i++)
+			free_block_list(&list[i]);
 		free(list);
+	}
 out_ts:
 	regfree(&ts_nsec_pattern);
 out_comm:
-- 
2.51.0