From b9b85be6ea97c126ad6f69f84f056bad6756ee5c Mon Sep 17 00:00:00 2001 From: Szabolcs Nagy Date: Thu, 4 Feb 2021 11:52:14 +0000 Subject: [PATCH] malloc: Avoid taggig mmaped memory on free Either the memory belongs to the dumped area, in which case we don't want to tag (the dumped area has the same tag as malloc internal data so tagging is unnecessary, but chunks there may not have the right alignment for the tag granule), or the memory will be unmapped immediately (and thus tagging is not useful). Reviewed-by: DJ Delorie --- malloc/malloc.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/malloc/malloc.c b/malloc/malloc.c index 9dd811b26a..339304269c 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -3284,9 +3284,6 @@ __libc_free (void *mem) p = mem2chunk (mem); - /* Mark the chunk as belonging to the library again. */ - (void)TAG_REGION (chunk2rawmem (p), CHUNK_AVAILABLE_SIZE (p) - CHUNK_HDR_SZ); - if (chunk_is_mmapped (p)) /* release mmapped memory. */ { /* See if the dynamic brk/mmap threshold needs adjusting. @@ -3307,6 +3304,10 @@ __libc_free (void *mem) { MAYBE_INIT_TCACHE (); + /* Mark the chunk as belonging to the library again. */ + (void)TAG_REGION (chunk2rawmem (p), + CHUNK_AVAILABLE_SIZE (p) - CHUNK_HDR_SZ); + ar_ptr = arena_for_chunk (p); _int_free (ar_ptr, p, 0); } -- 2.43.5