@matheusbsbs / matheus-bagliano / commits / 8cb5775b2b

grep: Fix race condition in delta_base_cache

When running large git grep (ie: git grep regexp $(git rev-list --all)), glibc error sometimes occur: *** glibc detected *** git: double free or corruption (!prev): 0x00000000010abdf0 *** According to gdb the problem originate from release_delta_cash (sha1_file.c:1703) free(ent->data); >From my analysis it seems that git grep threads do acquire lock before calling read_sha1_file but not before calling read_object_with_reference who ends up calling read_sha1_file too. Adding the lock around read_object_with_reference seems to fix the issue for me. I've ran git grep about a dozen time and seen no more error while it usually happened half the time before. Signed-off-by: Nicolas Morey-Chaisemartin <nicolas@morey-chaisemartin.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Nicolas Morey-Chaisemartin committed Aug 30, 2011 at 15:45 UTC 8cb5775b2b9885708c3f646a1e273de1ac778a88

1 file changed +4

builtin-grep.c

@@ -632,8 +632,12 @@ static int grep_object(struct grep_opt *opt, const char **paths,

632 void *data;

633 unsigned long size;

634 int hit;

635 +

636 + read_sha1_lock();

637 data = read_object_with_reference(obj->sha1, tree_type,

638 &size, NULL);

639 + read_sha1_unlock();

640 +

641 if (!data)

642 die("unable to read tree (%s)", sha1_to_hex(obj->sha1));

643 init_tree_desc(&tree, data, size);