diff mbox series

[05/16] malloc: Avoid taggig mmaped memory on free

Message ID e5fc33a9e1a955a12fb2c73dc9d623f5c5989f6d.1614874816.git.szabolcs.nagy@arm.com
State Committed
Commit b9b85be6ea97c126ad6f69f84f056bad6756ee5c
Headers show
Series memory tagging improvements | expand

Commit Message

Szabolcs Nagy March 4, 2021, 4:31 p.m. UTC
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).
---
 malloc/malloc.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/malloc/malloc.c b/malloc/malloc.c
index 4538a01614..b4c800bd7f 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);
     }