Commit 1ea048f6 authored by Paul Eggert's avatar Paul Eggert

Remove --enable-checking=xmallocoverrun

It doesn’t work anymore, and these days ‘gcc -fsanitize=address’
does a better job anyway.
* configure.ac: Remove the option.
* configure.ac (ac_xmalloc_overrun, XMALLOC_OVERRUN_CHECK):
* src/alloc.c (XMALLOC_OVERRUN_CHECK_OVERHEAD)
(XMALLOC_OVERRUN_CHECK_SIZE, XMALLOC_OVERRUN_SIZE_SIZE)
(xmalloc_overrun_check_header, xmalloc_overrun_check_trailer)
(xmalloc_put_size, xmalloc_get_size, overrun_check_malloc)
(overrun_check_realloc, overrun_check_free):
Remove.  All uses removed.
* etc/NEWS: Mention this.
parent 72067661
......@@ -545,7 +545,7 @@ AC_ARG_ENABLE(checking,
enable only specific categories of checks.
Categories are: all,yes,no.
Flags are: stringbytes, stringoverrun, stringfreelist,
structs, xmallocoverrun, glyphs])],
structs, glyphs])],
[ac_checking_flags="${enableval}"],[])
IFS="${IFS= }"; ac_save_IFS="$IFS"; IFS="$IFS,"
CHECK_STRUCTS=false
......@@ -559,21 +559,18 @@ do
ac_gc_check_stringbytes= ;
ac_gc_check_string_overrun= ;
ac_gc_check_string_free_list= ;
ac_xmalloc_overrun= ;
ac_glyphs_debug= ;;
all) ac_enable_checking=1 ;
CHECK_STRUCTS=true
ac_gc_check_stringbytes=1 ;
ac_gc_check_string_overrun=1 ;
ac_gc_check_string_free_list=1 ;
ac_xmalloc_overrun=1 ;
ac_glyphs_debug=1 ;;
# these enable particular checks
stringbytes) ac_gc_check_stringbytes=1 ;;
stringoverrun) ac_gc_check_string_overrun=1 ;;
stringfreelist) ac_gc_check_string_free_list=1 ;;
structs) CHECK_STRUCTS=true ;;
xmallocoverrun) ac_xmalloc_overrun=1 ;;
glyphs) ac_glyphs_debug=1 ;;
*) AC_MSG_ERROR(unknown check category $check) ;;
esac
......@@ -607,10 +604,6 @@ if test x$ac_gc_check_string_free_list != x ; then
AC_DEFINE(GC_CHECK_STRING_FREE_LIST, 1,
[Define this to check the string free list.])
fi
if test x$ac_xmalloc_overrun != x ; then
AC_DEFINE(XMALLOC_OVERRUN_CHECK, 1,
[Define this to check for malloc buffer overrun.])
fi
if test x$ac_glyphs_debug != x ; then
AC_DEFINE(GLYPH_DEBUG, 1,
[Define this to enable glyphs debugging code.])
......
......@@ -90,9 +90,10 @@ check that the portable dumper code has been updated to match the last
change to one of the data structures that it relies on.
+++
** The configure option '--enable-checking=conslist' has been withdrawn.
It made Emacs irredeemably slow, and is no longer useful with modern
debugging tools.
** The configure options '--enable-checking=conslist' and
'--enable-checking=xmallocoverrun' have been withdrawn. The former
made Emacs irredeemably slow, and the latter made it crash. Neither
option was useful with modern debugging tools.
---
** Emacs now requires GTK 2.24 and GTK 3.10 for the GTK 2 and GTK 3
......
......@@ -151,9 +151,7 @@ malloc_initialize_hook (void)
if (malloc_set_state (malloc_state_ptr) != 0)
emacs_abort ();
# ifndef XMALLOC_OVERRUN_CHECK
alloc_unexec_post ();
# endif
}
}
......@@ -651,171 +649,6 @@ verify (LISP_ALIGNMENT % GCALIGNMENT == 0);
it never does anything that requires an alignment of 16. */
enum { MALLOC_IS_LISP_ALIGNED = alignof (max_align_t) % LISP_ALIGNMENT == 0 };
#ifndef XMALLOC_OVERRUN_CHECK
#define XMALLOC_OVERRUN_CHECK_OVERHEAD 0
#else
/* Check for overrun in malloc'ed buffers by wrapping a header and trailer
around each block.
The header consists of XMALLOC_OVERRUN_CHECK_SIZE fixed bytes
followed by XMALLOC_OVERRUN_SIZE_SIZE bytes containing the original
block size in little-endian order. The trailer consists of
XMALLOC_OVERRUN_CHECK_SIZE fixed bytes.
The header is used to detect whether this block has been allocated
through these functions, as 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 + XMALLOC_OVERRUN_SIZE_SIZE)
/* Define XMALLOC_OVERRUN_SIZE_SIZE so that (1) it's large enough to
hold a size_t value and (2) the header size is a multiple of the
alignment that Emacs needs for C types and for USE_LSB_TAG. */
#define XMALLOC_OVERRUN_SIZE_SIZE \
(((XMALLOC_OVERRUN_CHECK_SIZE + sizeof (size_t) \
+ LISP_ALIGNMENT - 1) \
/ LISP_ALIGNMENT * LISP_ALIGNMENT) \
- XMALLOC_OVERRUN_CHECK_SIZE)
static char const xmalloc_overrun_check_header[XMALLOC_OVERRUN_CHECK_SIZE] =
{ '\x9a', '\x9b', '\xae', '\xaf',
'\xbf', '\xbe', '\xce', '\xcf',
'\xea', '\xeb', '\xec', '\xed',
'\xdf', '\xde', '\x9c', '\x9d' };
static char const xmalloc_overrun_check_trailer[XMALLOC_OVERRUN_CHECK_SIZE] =
{ '\xaa', '\xab', '\xac', '\xad',
'\xba', '\xbb', '\xbc', '\xbd',
'\xca', '\xcb', '\xcc', '\xcd',
'\xda', '\xdb', '\xdc', '\xdd' };
/* Insert and extract the block size in the header. */
static void
xmalloc_put_size (unsigned char *ptr, size_t size)
{
int i;
for (i = 0; i < XMALLOC_OVERRUN_SIZE_SIZE; i++)
{
*--ptr = size & ((1 << CHAR_BIT) - 1);
size >>= CHAR_BIT;
}
}
static size_t
xmalloc_get_size (unsigned char *ptr)
{
size_t size = 0;
int i;
ptr -= XMALLOC_OVERRUN_SIZE_SIZE;
for (i = 0; i < XMALLOC_OVERRUN_SIZE_SIZE; i++)
{
size <<= CHAR_BIT;
size += *ptr++;
}
return size;
}
/* Like malloc, but wraps allocated block with header and trailer. */
static void *
overrun_check_malloc (size_t size)
{
register unsigned char *val;
if (SIZE_MAX - XMALLOC_OVERRUN_CHECK_OVERHEAD < size)
emacs_abort ();
val = malloc (size + XMALLOC_OVERRUN_CHECK_OVERHEAD);
if (val)
{
memcpy (val, xmalloc_overrun_check_header, XMALLOC_OVERRUN_CHECK_SIZE);
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);
}
return val;
}
/* Like realloc, but checks old block for overrun, and wraps new block
with header and trailer. */
static void *
overrun_check_realloc (void *block, size_t size)
{
register unsigned char *val = (unsigned char *) block;
if (SIZE_MAX - XMALLOC_OVERRUN_CHECK_OVERHEAD < size)
emacs_abort ();
if (val
&& memcmp (xmalloc_overrun_check_header,
val - XMALLOC_OVERRUN_CHECK_SIZE - XMALLOC_OVERRUN_SIZE_SIZE,
XMALLOC_OVERRUN_CHECK_SIZE) == 0)
{
size_t osize = xmalloc_get_size (val);
if (memcmp (xmalloc_overrun_check_trailer, val + osize,
XMALLOC_OVERRUN_CHECK_SIZE))
emacs_abort ();
memset (val + osize, 0, XMALLOC_OVERRUN_CHECK_SIZE);
val -= XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE;
memset (val, 0, XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE);
}
val = realloc (val, size + XMALLOC_OVERRUN_CHECK_OVERHEAD);
if (val)
{
memcpy (val, xmalloc_overrun_check_header, XMALLOC_OVERRUN_CHECK_SIZE);
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);
}
return val;
}
/* Like free, but checks block for overrun. */
static void
overrun_check_free (void *block)
{
unsigned char *val = (unsigned char *) block;
if (val
&& memcmp (xmalloc_overrun_check_header,
val - XMALLOC_OVERRUN_CHECK_SIZE - XMALLOC_OVERRUN_SIZE_SIZE,
XMALLOC_OVERRUN_CHECK_SIZE) == 0)
{
size_t osize = xmalloc_get_size (val);
if (memcmp (xmalloc_overrun_check_trailer, val + osize,
XMALLOC_OVERRUN_CHECK_SIZE))
emacs_abort ();
#ifdef XMALLOC_CLEAR_FREE_MEMORY
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 + XMALLOC_OVERRUN_SIZE_SIZE;
memset (val, 0, XMALLOC_OVERRUN_CHECK_SIZE + XMALLOC_OVERRUN_SIZE_SIZE);
#endif
}
free (val);
}
#undef malloc
#undef realloc
#undef free
#define malloc overrun_check_malloc
#define realloc overrun_check_realloc
#define free overrun_check_free
#endif
/* If compiled with XMALLOC_BLOCK_INPUT_CHECK, define a symbol
BLOCK_INPUT_IN_MEMORY_ALLOCATORS that is visible to the debugger.
If that variable is set, block input while in one of Emacs's memory
......@@ -1790,7 +1623,7 @@ static char const string_overrun_cookie[GC_STRING_OVERRUN_COOKIE_SIZE] =
calculating a value to be passed to malloc. */
static ptrdiff_t const STRING_BYTES_MAX =
min (STRING_BYTES_BOUND,
((SIZE_MAX - XMALLOC_OVERRUN_CHECK_OVERHEAD
((SIZE_MAX
- GC_STRING_EXTRA
- offsetof (struct sblock, data)
- SDATA_DATA_OFFSET)
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment