From: Siddhesh Poyarekar <siddhesh@sourceware.org>
To: libc-alpha@sourceware.org
Subject: [PATCH] malloc-debug: Return 0 on NULL input [BZ #28506]
Date: Fri, 29 Oct 2021 08:35:28 +0530 [thread overview]
Message-ID: <20211029030528.3504087-1-siddhesh@sourceware.org> (raw)
Hoist the NULL check for malloc_usable_size into its entry points in
malloc-debug and malloc and assume non-NULL in all callees. This fixes
BZ #28506
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
---
malloc/malloc-debug.c | 12 ++++++------
malloc/malloc.c | 23 ++++++++++-------------
2 files changed, 16 insertions(+), 19 deletions(-)
diff --git a/malloc/malloc-debug.c b/malloc/malloc-debug.c
index 9922ef5f25..5e954d7dc2 100644
--- a/malloc/malloc-debug.c
+++ b/malloc/malloc-debug.c
@@ -399,17 +399,17 @@ strong_alias (__debug_calloc, calloc)
size_t
malloc_usable_size (void *mem)
{
+ if (mem == NULL)
+ return 0;
+
if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK))
return mcheck_usable_size (mem);
if (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK))
return malloc_check_get_size (mem);
- if (mem != NULL)
- {
- mchunkptr p = mem2chunk (mem);
- if (DUMPED_MAIN_ARENA_CHUNK (p))
- return chunksize (p) - SIZE_SZ;
- }
+ mchunkptr p = mem2chunk (mem);
+ if (DUMPED_MAIN_ARENA_CHUNK (p))
+ return chunksize (p) - SIZE_SZ;
return musable (mem);
}
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 2ba1fee144..9a345572a1 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -5008,29 +5008,26 @@ static size_t
musable (void *mem)
{
mchunkptr p;
- if (mem != 0)
- {
- size_t result = 0;
+ size_t result = 0;
- p = mem2chunk (mem);
+ p = mem2chunk (mem);
- if (chunk_is_mmapped (p))
- result = chunksize (p) - CHUNK_HDR_SZ;
- else if (inuse (p))
- result = memsize (p);
+ if (chunk_is_mmapped (p))
+ result = chunksize (p) - CHUNK_HDR_SZ;
+ else if (inuse (p))
+ result = memsize (p);
- return result;
- }
- return 0;
+ return result;
}
#if IS_IN (libc)
size_t
__malloc_usable_size (void *m)
{
- size_t result;
+ size_t result = 0;
- result = musable (m);
+ if (m != NULL)
+ result = musable (m);
return result;
}
#endif
--
2.31.1
next reply other threads:[~2021-10-29 3:05 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-29 3:05 Siddhesh Poyarekar [this message]
2021-10-29 3:14 ` Siddhesh Poyarekar
2021-10-29 8:53 ` Richard W.M. Jones
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