[PATCH] grep: Fix race condition in delta_base_cache
- From
Nicolas Morey-Chaisemartin <devel-git@morey-chaisemartin.com>
- Date
- Aug 30, 2011, 13:45 UTC
- Message-ID
- <4E5CE982.7080200@morey-chaisemartin.com>
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> --- builtin/grep.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/builtin/grep.c b/builtin/grep.c index 1c359c2..56398d5 100644 --- a/builtin/grep.c +++ b/builtin/grep.c @@ -598,8 +598,10 @@ static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec, struct strbuf base; int hit, len; + read_sha1_lock(); data = read_object_with_reference(obj->sha1, tree_type, &size, NULL); + read_sha1_unlock(); if (!data) die(_("unable to read tree (%s)"), sha1_to_hex(obj->sha1));