undef/git-commit-vandalism
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

grep: take the read-lock when adding a submodule

Browse Source 
With --recurse-submodules, we add each submodule that we encounter to
the list of alternate object databases. With threading, our changes to
the list are not protected against races. Indeed, ThreadSanitizer
reports a race when we call `add_to_alternates_memory()` around the same
time that another thread is reading in the list through
`read_sha1_file()`.

Take the grep read-lock while adding the submodule. The lock is used to
serialize uses of non-thread-safe parts of Git's API, including
`read_sha1_file()`.

Helped-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Acked-by: Brandon Williams <bmwill@google.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Martin Ågren 2017-11-01 21:45:06 +01:00 committed by Junio C Hamano
parent f9ee2fcdfa
commit 9560e6245a
1 changed files with 2 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
builtin/grep.c
View File

@ -431,7 +431,9 @@ static int grep_submodule(struct grep_opt *opt, struct repository *superproject,
* store is no longer global and instead is a member of the repository
* object.
*/
grep_read_lock();
add_to_alternates_memory(submodule.objectdir);
grep_read_unlock();
if (oid) {
struct object *object;