@matheusbsbs / matheus-bagliano / commits / 6cdb67b97d

pack-bitmap-write: deep-clear the `bb_commit` slab

The `bb_commit` commit slab is used by the pack-bitmap-write machinery to track various pieces of bookkeeping used to generate reachability bitmaps. Even though we clear the slab when freeing the bitmap_builder struct (with `bitmap_builder_clear()`), there are still pointers which point to locations in memory that have not yet been freed, resulting in a leak. Plug the leak by introducing a suitable `free_fn` for the `struct bb_commit` type, and make sure it is called on each member of the slab via the `deep_clear_bb_data()` function. Note that it is possible for both of the arguments to `bitmap_free()` to be NULL, but `bitmap_free()` is a noop for NULL arguments, so it is OK to pass them unconditionally. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Taylor Blau committed Dec 14, 2023 at 17:23 UTC 6cdb67b97d188ea5583f33ac09f4649be5f9741f

1 file changed +8 -1

pack-bitmap-write.c

+8 -1

@@ -198,6 +198,13 @@ struct bb_commit {

198 unsigned idx; /* within selected array */

199 };

200

201 +static void clear_bb_commit(struct bb_commit *commit)

202 +{

203 + free_commit_list(commit->reverse_edges);

204 + bitmap_free(commit->commit_mask);

205 + bitmap_free(commit->bitmap);

206 +}

207 +

208 define_commit_slab(bb_data, struct bb_commit);

209

210 struct bitmap_builder {

@@ -339,7 +346,7 @@ next:

346

347 static void bitmap_builder_clear(struct bitmap_builder *bb)

348 {

342 - clear_bb_data(&bb->data);

349 + deep_clear_bb_data(&bb->data, clear_bb_commit);

350 free(bb->commits);

351 bb->commits_nr = bb->commits_alloc = 0;

352 }