Message ID | 80fb4a2a-992f-7d3b-9413-5059da3a8f01@web.de (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | diff-lib: plug minor memory leaks in do_diff_cache() | expand |
On Sat, Nov 14, 2020 at 07:37:03PM +0100, René Scharfe wrote: > do_diff_cache() builds a struct rev_info to hand to diff_cache() from > scratch by initializing it using repo_init_revisions() and then > replacing its diffopt and prune_data members. > > The diffopt member is initialized to a heap-allocated list of options, > though. Release it using diff_setup_done() before overwriting it. Makes sense. This whole "rewrite the options as a heap-allocated list" thing is pretty gross, but is probably the least-bad solution to the problem. I wondered if there might be other unpaired diff_setup() / diff_setup_done() calls. Curiously, there are more of the latter: $ git grep 'diff_setup(' | wc -l 22 $ git grep 'diff_setup_done(' | wc -l 35 I think because repo_init_revisions() makes an implicit call to diff_setup(). > The initial value of the prune_data member doesn't need to be released, > but the copy created using copy_pathspec() does. Clear it after use. I suspect there are more elements of rev_info that could be allocated (e.g., in a traversal without "--objects", I think trees and blobs are left sitting in the pending array). It's a prime candidate for UNLEAK() in most cases where we do a single traversal and then exit the program. But for sub-functions like this, we perhaps should bite the bullet and just make a rev_info_clear() function that can be used everywhere. (I'm not opposed to your patch here in the meantime, though). -Peff
diff --git a/diff-lib.c b/diff-lib.c index 082e249fc3..b73cc1859a 100644 --- a/diff-lib.c +++ b/diff-lib.c @@ -606,10 +606,12 @@ int do_diff_cache(const struct object_id *tree_oid, struct diff_options *opt) repo_init_revisions(opt->repo, &revs, NULL); copy_pathspec(&revs.prune_data, &opt->pathspec); + diff_setup_done(&revs.diffopt); revs.diffopt = *opt; if (diff_cache(&revs, tree_oid, NULL, 1)) exit(128); + clear_pathspec(&revs.prune_data); return 0; }
do_diff_cache() builds a struct rev_info to hand to diff_cache() from scratch by initializing it using repo_init_revisions() and then replacing its diffopt and prune_data members. The diffopt member is initialized to a heap-allocated list of options, though. Release it using diff_setup_done() before overwriting it. The initial value of the prune_data member doesn't need to be released, but the copy created using copy_pathspec() does. Clear it after use. Signed-off-by: René Scharfe <l.s.r@web.de> --- diff-lib.c | 2 ++ 1 file changed, 2 insertions(+) -- 2.29.2