diff options
Diffstat (limited to 'src/alloc.c')
| -rw-r--r-- | src/alloc.c | 47 |
1 files changed, 15 insertions, 32 deletions
diff --git a/src/alloc.c b/src/alloc.c index ad1741e308f..4c5094b8f48 100644 --- a/src/alloc.c +++ b/src/alloc.c @@ -482,27 +482,10 @@ buffer_memory_full (EMACS_INT nbytes) xsignal (Qnil, Vmemory_signal_data); } - -#ifndef XMALLOC_OVERRUN_CHECK -#define XMALLOC_OVERRUN_CHECK_OVERHEAD 0 -#else +#ifdef XMALLOC_OVERRUN_CHECK /* Check for overrun in malloc'ed buffers by wrapping a header and trailer - around each block. - - The header consists of 16 fixed bytes followed by sizeof (size_t) bytes - containing the original block size in little-endian order, - while the trailer consists of 16 fixed bytes. - - The header is used to detect whether this block has been allocated - through these functions -- as it seems that some low-level libc - functions may bypass the malloc hooks. -*/ - - -#define XMALLOC_OVERRUN_CHECK_SIZE 16 -#define XMALLOC_OVERRUN_CHECK_OVERHEAD \ - (2 * XMALLOC_OVERRUN_CHECK_SIZE + sizeof (size_t)) + around each block. */ static char const xmalloc_overrun_check_header[XMALLOC_OVERRUN_CHECK_SIZE] = { '\x9a', '\x9b', '\xae', '\xaf', @@ -522,9 +505,9 @@ static void xmalloc_put_size (unsigned char *ptr, size_t size) { int i; - for (i = 0; i < sizeof (size_t); i++) + for (i = 0; i < XMALLOC_OVERRUN_SIZE_SIZE; i++) { - *--ptr = size & (1 << CHAR_BIT) - 1; + *--ptr = size & ((1 << CHAR_BIT) - 1); size >>= CHAR_BIT; } } @@ -534,8 +517,8 @@ xmalloc_get_size (unsigned char *ptr) { size_t size = 0; int i; - ptr -= sizeof (size_t); - for (i = 0; i < sizeof (size_t); i++) + ptr -= XMALLOC_OVERRUN_SIZE_SIZE; + for (i = 0; i < XMALLOC_OVERRUN_SIZE_SIZE; i++) { size <<= CHAR_BIT; size += *ptr++; @@ -579,7 +562,7 @@ overrun_check_malloc (size_t size) if (val && check_depth == 1) { memcpy (val, xmalloc_overrun_check_header, XMALLOC_OVERRUN_CHECK_SIZE); - val += XMALLOC_OVERRUN_CHECK_SIZE + sizeof (size_t); + val += XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE; xmalloc_put_size (val, size); memcpy (val + size, xmalloc_overrun_check_trailer, XMALLOC_OVERRUN_CHECK_SIZE); @@ -603,7 +586,7 @@ overrun_check_realloc (POINTER_TYPE *block, size_t size) if (val && check_depth == 1 && memcmp (xmalloc_overrun_check_header, - val - XMALLOC_OVERRUN_CHECK_SIZE - sizeof (size_t), + val - XMALLOC_OVERRUN_CHECK_SIZE - XMALLOC_OVERRUN_SIZE_SIZE, XMALLOC_OVERRUN_CHECK_SIZE) == 0) { size_t osize = xmalloc_get_size (val); @@ -611,8 +594,8 @@ overrun_check_realloc (POINTER_TYPE *block, size_t size) XMALLOC_OVERRUN_CHECK_SIZE)) abort (); memset (val + osize, 0, XMALLOC_OVERRUN_CHECK_SIZE); - val -= XMALLOC_OVERRUN_CHECK_SIZE + sizeof (size_t); - memset (val, 0, XMALLOC_OVERRUN_CHECK_SIZE + sizeof (size_t)); + val -= XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE; + memset (val, 0, XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE); } val = (unsigned char *) realloc ((POINTER_TYPE *)val, size + overhead); @@ -620,7 +603,7 @@ overrun_check_realloc (POINTER_TYPE *block, size_t size) if (val && check_depth == 1) { memcpy (val, xmalloc_overrun_check_header, XMALLOC_OVERRUN_CHECK_SIZE); - val += XMALLOC_OVERRUN_CHECK_SIZE + sizeof (size_t); + val += XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE; xmalloc_put_size (val, size); memcpy (val + size, xmalloc_overrun_check_trailer, XMALLOC_OVERRUN_CHECK_SIZE); @@ -640,7 +623,7 @@ overrun_check_free (POINTER_TYPE *block) if (val && check_depth == 1 && memcmp (xmalloc_overrun_check_header, - val - XMALLOC_OVERRUN_CHECK_SIZE - sizeof (size_t), + val - XMALLOC_OVERRUN_CHECK_SIZE - XMALLOC_OVERRUN_SIZE_SIZE, XMALLOC_OVERRUN_CHECK_SIZE) == 0) { size_t osize = xmalloc_get_size (val); @@ -648,12 +631,12 @@ overrun_check_free (POINTER_TYPE *block) XMALLOC_OVERRUN_CHECK_SIZE)) abort (); #ifdef XMALLOC_CLEAR_FREE_MEMORY - val -= XMALLOC_OVERRUN_CHECK_SIZE + sizeof (size_t); + val -= XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE; memset (val, 0xff, osize + XMALLOC_OVERRUN_CHECK_OVERHEAD); #else memset (val + osize, 0, XMALLOC_OVERRUN_CHECK_SIZE); - val -= XMALLOC_OVERRUN_CHECK_SIZE + sizeof (size_t); - memset (val, 0, XMALLOC_OVERRUN_CHECK_SIZE + sizeof (size_t)); + val -= XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE; + memset (val, 0, XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE); #endif } |