tools/mm/page_owner_sort: return explicit filter results

Patch series "tools/mm/page_owner_sort: fix filtering and cleanup issues",
v5.

Patch 1 renames is_need() to filter_record() and makes the filter path
return explicit results.  Patch 2 fixes the per-record allocation leaks. 
Patch 3 bounds search_pattern() output copies, addressing the pre-existing
issue reported by Sashiko/AI review.


This patch (of 3):

Rename is_need() to filter_record() and make the filter path return
explicit error, skip, and match results.  This lets callers distinguish
allocation failures from records that simply do not match active filters.

Link: https://lore.kernel.org/20260629014316.130307-1-chenyichong@uniontech.com
Link: https://lore.kernel.org/20260629014316.130307-2-chenyichong@uniontech.com
Signed-off-by: Yichong Chen <chenyichong@uniontech.com>
Reviewed-by: Vishal Moola <vishal.moola@gmail.com>
Cc: Ye Liu <ye.liu@linux.dev>
Cc: Zhen Ni <zhen.ni@easystack.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 31 insertions, 9 deletions

diff --git a/tools/mm/page_owner_sort.c b/tools/mm/page_owner_sort.c
index e6954909401c..3c754826cec5 100644
--- a/tools/mm/page_owner_sort.c
+++ b/tools/mm/page_owner_sort.c
@@ -43,6 +43,13 @@ enum FILTER_BIT {
 	FILTER_TGID = 1<<2,
 	FILTER_COMM = 1<<3
 };
+
+enum FILTER_RESULT {
+	FILTER_ERROR,
+	FILTER_SKIP,
+	FILTER_MATCH
+};
+
 enum CULL_BIT {
 	CULL_PID = 1<<1,
 	CULL_TGID = 1<<2,
@@ -372,6 +379,9 @@ 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);
@@ -450,32 +460,44 @@ static bool match_str_list(const char *str, char **list, int list_size)
 	return false;
 }
 
-static bool is_need(char *buf)
+static enum FILTER_RESULT filter_record(char *buf)
 {
+	char *comm;
+
 	if ((filter & FILTER_PID) && !match_num_list(get_pid(buf), fc.pids, fc.pids_size))
-		return false;
+		return FILTER_SKIP;
 	if ((filter & FILTER_TGID) &&
 		!match_num_list(get_tgid(buf), fc.tgids, fc.tgids_size))
-		return false;
+		return FILTER_SKIP;
+	if (!(filter & FILTER_COMM))
+		return FILTER_MATCH;
 
-	char *comm = get_comm(buf);
+	comm = get_comm(buf);
+	if (!comm)
+		return FILTER_ERROR;
 
-	if ((filter & FILTER_COMM) &&
-	!match_str_list(comm, fc.comms, fc.comms_size)) {
+	if (!match_str_list(comm, fc.comms, fc.comms_size)) {
 		free(comm);
-		return false;
+		return FILTER_SKIP;
 	}
 	free(comm);
-	return true;
+	return FILTER_MATCH;
 }
 
 static bool add_list(char *buf, int len, char *ext_buf)
 {
+	enum FILTER_RESULT filter_result;
+
 	if (list_size == max_size) {
 		fprintf(stderr, "max_size too small??\n");
 		return false;
 	}
-	if (!is_need(buf))
+	filter_result = filter_record(buf);
+	if (filter_result == FILTER_ERROR) {
+		fprintf(stderr, "Out of memory\n");
+		return false;
+	}
+	if (filter_result == FILTER_SKIP)
 		return true;
 	list[list_size].pid = get_pid(buf);
 	list[list_size].tgid = get_tgid(buf);