Re: What's cooking in git.git (Sep 2016, #03; Fri, 9)
From: Junio C Hamano <hidden>
Date: 2016-09-12 19:10:27
Jeff King [off-list ref] writes:
I happened to notice today that this topic needs a minor tweak: -- >8 -- Subject: [PATCH] add_delta_base_cache: use list_for_each_safe We may remove elements from the list while we are iterating, which requires using a second temporary pointer. Otherwise stepping to the next element of the list might involve looking at freed memory (which generally works in practice, as we _just_ freed it, but of course is wrong to rely on; valgrind notices it).
I failed to notice it, too. Thanks.
quoted hunk
Signed-off-by: Jeff King <redacted> --- sha1_file.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)diff --git a/sha1_file.c b/sha1_file.c index a57b71d..132c861 100644 --- a/sha1_file.c +++ b/sha1_file.c@@ -2187,11 +2187,11 @@ static void add_delta_base_cache(struct packed_git *p, off_t base_offset, void *base, unsigned long base_size, enum object_type type) { struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent)); - struct list_head *lru; + struct list_head *lru, *tmp; delta_base_cached += base_size; - list_for_each(lru, &delta_base_cache_lru) { + list_for_each_safe(lru, tmp, &delta_base_cache_lru) { struct delta_base_cache_entry *f = list_entry(lru, struct delta_base_cache_entry, lru); if (delta_base_cached <= delta_base_cache_limit)