diff mbox series

[03/13] dir.c: free strings in sparse cone pattern hashmaps

Message ID 20240531112657.GC428814@coredump.intra.peff.net (mailing list archive)
State Superseded
Headers show
Series leak fixes for sparse-checkout code | expand

Commit Message

Jeff King May 31, 2024, 11:26 a.m. UTC
The pattern_list structs used for cone-mode sparse lookups use a few
extra hashmaps. These store pattern_entry structs, each of which has its
own heap-allocated pattern string. When we clean up the hashmaps, we
free the individual pattern_entry structs, but forget to clean up the
embedded strings, causing memory leaks.

We can fix this by iterating over the hashmaps to free the extra
strings. This reduces the numbers of leaks in t7002 from 22 to 9.

One alternative here would be to make the string a FLEX_ARRAY member of
the pattern_entry. Then there's no extra free() required, and as a bonus
it would be a little more efficient. However, some of the refactoring
gets awkward, as we are often assigning strings allocated by helper
functions. So let's just fix the leak for now, and we can explore bigger
refactoring separately.

Signed-off-by: Jeff King <peff@peff.net>
---
 dir.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/dir.c b/dir.c
index 2d83f3311a..9cc4a68fbc 100644
--- a/dir.c
+++ b/dir.c
@@ -726,6 +726,17 @@  static char *dup_and_filter_pattern(const char *pattern)
 	return result;
 }
 
+static void clear_pattern_entry_hashmap(struct hashmap *map)
+{
+	struct hashmap_iter iter;
+	struct pattern_entry *entry;
+
+	hashmap_for_each_entry(map, &iter, entry, ent) {
+		free(entry->pattern);
+	}
+	hashmap_clear_and_free(map, struct pattern_entry, ent);
+}
+
 static void add_pattern_to_hashsets(struct pattern_list *pl, struct path_pattern *given)
 {
 	struct pattern_entry *translated;
@@ -855,8 +866,8 @@  static void add_pattern_to_hashsets(struct pattern_list *pl, struct path_pattern
 
 clear_hashmaps:
 	warning(_("disabling cone pattern matching"));
-	hashmap_clear_and_free(&pl->parent_hashmap, struct pattern_entry, ent);
-	hashmap_clear_and_free(&pl->recursive_hashmap, struct pattern_entry, ent);
+	clear_pattern_entry_hashmap(&pl->recursive_hashmap);
+	clear_pattern_entry_hashmap(&pl->parent_hashmap);
 	pl->use_cone_patterns = 0;
 }
 
@@ -956,8 +967,8 @@  void clear_pattern_list(struct pattern_list *pl)
 		free(pl->patterns[i]);
 	free(pl->patterns);
 	free(pl->filebuf);
-	hashmap_clear_and_free(&pl->recursive_hashmap, struct pattern_entry, ent);
-	hashmap_clear_and_free(&pl->parent_hashmap, struct pattern_entry, ent);
+	clear_pattern_entry_hashmap(&pl->recursive_hashmap);
+	clear_pattern_entry_hashmap(&pl->parent_hashmap);
 
 	memset(pl, 0, sizeof(*pl));
 }