[mono] Fix a race in gparam construction. (#83688)

Re: #81123.
dotnet · Mar 20, 2023 · 059898f · 059898f
1 parent dcd0506
commit 059898f
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/src/mono/mono/metadata/metadata.c b/src/mono/mono/metadata/metadata.c
@@ -3734,12 +3734,14 @@ publish_anon_gparam_fast (MonoImage *image, MonoGenericContainer *container, gin
 	if (!*cache) {
 		mono_image_lock (image);
 		if (!*cache) {
-			*cache = (MonoGenericParam*)mono_image_alloc0 (image, sizeof (MonoGenericParam) * FAST_GPARAM_CACHE_SIZE);
+			MonoGenericParam *new_cache = (MonoGenericParam*)mono_image_alloc0 (image, sizeof (MonoGenericParam) * FAST_GPARAM_CACHE_SIZE);
 			for (guint16 i = 0; i < FAST_GPARAM_CACHE_SIZE; ++i) {
-				MonoGenericParam *param = &(*cache)[i];
+				MonoGenericParam *param = &new_cache[i];
 				param->owner = container;
 				param->num = i;
 			}
+			mono_memory_barrier ();
+			*cache = new_cache;
 		}
 		mono_image_unlock (image);
 	}