From 347c92e9e78c39d8494c8497f420a7fa30c89565 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Thu, 24 May 2012 17:50:28 -0700 Subject: [PATCH] Make free chunk size a multiple of MALLOC_ALIGNMENT --- ChangeLog | 7 +++++++ malloc/malloc.c | 10 ++++++---- 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/ChangeLog b/ChangeLog index dbf24e22a6..ac5a8984d6 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2012-05-24 H.J. Lu + + [BZ #13576] + * malloc/malloc.c (sYSMALLOc): Free the old top chunk with a + multiple of MALLOC_ALIGNMENT in size. + (_int_free): Check chunk size is a multiple of MALLOC_ALIGNMENT. + 2012-05-24 Joseph Myers * conform/data/stdio.h-data (BUFSIZ): Use macro-int-constant. diff --git a/malloc/malloc.c b/malloc/malloc.c index 447b622342..28039b4720 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -2396,11 +2396,12 @@ static void* sysmalloc(INTERNAL_SIZE_T nb, mstate av) top(av) = chunk_at_offset(heap, sizeof(*heap)); set_head(top(av), (heap->size - sizeof(*heap)) | PREV_INUSE); - /* Setup fencepost and free the old top chunk. */ + /* Setup fencepost and free the old top chunk with a multiple of + MALLOC_ALIGNMENT in size. */ /* The fencepost takes at least MINSIZE bytes, because it might become the top chunk again later. Note that a footer is set up, too, although the chunk is marked in use. */ - old_size -= MINSIZE; + old_size = (old_size - MINSIZE) & ~MALLOC_ALIGN_MASK; set_head(chunk_at_offset(old_top, old_size + 2*SIZE_SZ), 0|PREV_INUSE); if (old_size >= MINSIZE) { set_head(chunk_at_offset(old_top, old_size), (2*SIZE_SZ)|PREV_INUSE); @@ -3809,8 +3810,9 @@ _int_free(mstate av, mchunkptr p, int have_lock) malloc_printerr (check_action, errstr, chunk2mem(p)); return; } - /* We know that each chunk is at least MINSIZE bytes in size. */ - if (__builtin_expect (size < MINSIZE, 0)) + /* We know that each chunk is at least MINSIZE bytes in size or a + multiple of MALLOC_ALIGNMENT. */ + if (__builtin_expect (size < MINSIZE || !aligned_OK (size), 0)) { errstr = "free(): invalid size"; goto errout;