From 84c202246b74c2f75b36985ceff506b7a152c2fb Mon Sep 17 00:00:00 2001 From: Siddhesh Poyarekar Date: Wed, 23 Dec 2020 07:41:17 +0530 Subject: MTE: Do not pad size in realloc_check The MTE patch to add malloc support incorrectly padded the size passed to _int_realloc by SIZE_SZ when it ought to have sent just the chunksize. Revert that bit of the change so that realloc works correctly with MALLOC_CHECK_ set. This also brings the realloc_check implementation back in sync with libc_realloc. --- malloc/hooks.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'malloc') diff --git a/malloc/hooks.c b/malloc/hooks.c index 8a1c16dfa4..6474ba8b38 100644 --- a/malloc/hooks.c +++ b/malloc/hooks.c @@ -315,7 +315,7 @@ realloc_check (void *oldmem, size_t bytes, const void *caller) __libc_lock_unlock (main_arena.mutex); if (!oldp) malloc_printerr ("realloc(): invalid pointer"); - const INTERNAL_SIZE_T oldchsize = CHUNK_AVAILABLE_SIZE (oldp); + const INTERNAL_SIZE_T oldsize = chunksize (oldp); if (!checked_request2size (rb, &chnb)) goto invert; @@ -331,7 +331,8 @@ realloc_check (void *oldmem, size_t bytes, const void *caller) else #endif { - if (oldchsize >= chnb) + /* Note the extra SIZE_SZ overhead. */ + if (oldsize - SIZE_SZ >= chnb) newmem = oldmem; /* do nothing */ else { @@ -340,7 +341,7 @@ realloc_check (void *oldmem, size_t bytes, const void *caller) newmem = _int_malloc (&main_arena, rb); if (newmem) { - memcpy (newmem, oldmem, oldchsize - CHUNK_HDR_SZ); + memcpy (newmem, oldmem, oldsize - CHUNK_HDR_SZ); munmap_chunk (oldp); } } @@ -349,7 +350,7 @@ realloc_check (void *oldmem, size_t bytes, const void *caller) else { top_check (); - newmem = _int_realloc (&main_arena, oldp, oldchsize, chnb); + newmem = _int_realloc (&main_arena, oldp, oldsize, chnb); } DIAG_PUSH_NEEDS_COMMENT; -- cgit 1.4.1