[thirdparty/glibc.git] / malloc / mcheck.c

/* Standard debugging hooks for `malloc'.
   Copyright (C) 1990,91,92,93,94,95,96,97,99 Free Software Foundation, Inc.
   Written May 1989 by Mike Haertel.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.

   The author may be reached (Email) at the address mike@ai.mit.edu,
   or (US mail) as Mike Haertel c/o Free Software Foundation.  */

#ifndef	_MALLOC_INTERNAL
# define _MALLOC_INTERNAL
# include <malloc.h>
# include <mcheck.h>
# include <stdio.h>
#endif

/* Old hook values.  */
static void (*old_free_hook) __P ((__ptr_t ptr, __const __ptr_t));
static __ptr_t (*old_malloc_hook) __P ((__malloc_size_t size, const __ptr_t));
static __ptr_t (*old_realloc_hook) __P ((__ptr_t ptr, __malloc_size_t size,
					 __const __ptr_t));

/* Function to call when something awful happens.  */
static void (*abortfunc) __P ((enum mcheck_status));

/* Arbitrary magical numbers.  */
#define MAGICWORD	0xfedabeeb
#define MAGICFREE	0xd8675309
#define MAGICBYTE	((char) 0xd7)
#define MALLOCFLOOD	((char) 0x93)
#define FREEFLOOD	((char) 0x95)

struct hdr
  {
    __malloc_size_t size;		/* Exact size requested by user.  */
    unsigned long int magic;	/* Magic number to check header integrity.  */
  };

#if defined _LIBC || defined STDC_HEADERS || defined USG
# include <string.h>
# define flood memset
#else
static void flood __P ((__ptr_t, int, __malloc_size_t));
static void
flood (ptr, val, size)
     __ptr_t ptr;
     int val;
     __malloc_size_t size;
{
  char *cp = ptr;
  while (size--)
    *cp++ = val;
}
#endif

static enum mcheck_status checkhdr __P ((const struct hdr *));
static enum mcheck_status
checkhdr (hdr)
     const struct hdr *hdr;
{
  enum mcheck_status status;
  switch (hdr->magic)
    {
    default:
      status = MCHECK_HEAD;
      break;
    case MAGICFREE:
      status = MCHECK_FREE;
      break;
    case MAGICWORD:
      if (((char *) &hdr[1])[hdr->size] != MAGICBYTE)
	status = MCHECK_TAIL;
      else
	status = MCHECK_OK;
      break;
    }
  if (status != MCHECK_OK)
    (*abortfunc) (status);
  return status;
}

static void freehook __P ((__ptr_t, const __ptr_t));
static void
freehook (ptr, caller)
     __ptr_t ptr;
     const __ptr_t caller;
{
  if (ptr)
    {
      struct hdr *hdr = ((struct hdr *) ptr) - 1;
      checkhdr (hdr);
      hdr->magic = MAGICFREE;
      flood (ptr, FREEFLOOD, hdr->size);
      ptr = (__ptr_t) hdr;
    }
  __free_hook = old_free_hook;
  if (old_free_hook != NULL)
    (*old_free_hook) (ptr, caller);
  else
    free (ptr);
  __free_hook = freehook;
}

static __ptr_t mallochook __P ((__malloc_size_t, const __ptr_t));
static __ptr_t
mallochook (size, caller)
     __malloc_size_t size;
     const __ptr_t caller;
{
  struct hdr *hdr;

  __malloc_hook = old_malloc_hook;
  if (old_malloc_hook != NULL)
    hdr = (struct hdr *) (*old_malloc_hook) (sizeof (struct hdr) + size + 1,
					     caller);
  else
    hdr = (struct hdr *) malloc (sizeof (struct hdr) + size + 1);
  __malloc_hook = mallochook;
  if (hdr == NULL)
    return NULL;

  hdr->size = size;
  hdr->magic = MAGICWORD;
  ((char *) &hdr[1])[size] = MAGICBYTE;
  flood ((__ptr_t) (hdr + 1), MALLOCFLOOD, size);
  return (__ptr_t) (hdr + 1);
}

static __ptr_t reallochook __P ((__ptr_t, __malloc_size_t, const __ptr_t));
static __ptr_t
reallochook (ptr, size, caller)
     __ptr_t ptr;
     __malloc_size_t size;
     const __ptr_t caller;
{
  struct hdr *hdr;
  __malloc_size_t osize;

  if (ptr)
    {
      hdr = ((struct hdr *) ptr) - 1;
      osize = hdr->size;

      checkhdr (hdr);
      if (size < osize)
	flood ((char *) ptr + size, FREEFLOOD, osize - size);
    }
  else
    {
      osize = 0;
      hdr = NULL;
    }
  __free_hook = old_free_hook;
  __malloc_hook = old_malloc_hook;
  __realloc_hook = old_realloc_hook;
  if (old_realloc_hook != NULL)
    hdr = (struct hdr *) (*old_realloc_hook) ((__ptr_t) hdr,
					      sizeof (struct hdr) + size + 1,
					      caller);
  else
    hdr = (struct hdr *) realloc ((__ptr_t) hdr,
				  sizeof (struct hdr) + size + 1);
  __free_hook = freehook;
  __malloc_hook = mallochook;
  __realloc_hook = reallochook;
  if (hdr == NULL)
    return NULL;

  hdr->size = size;
  hdr->magic = MAGICWORD;
  ((char *) &hdr[1])[size] = MAGICBYTE;
  if (size > osize)
    flood ((char *) (hdr + 1) + osize, MALLOCFLOOD, size - osize);
  return (__ptr_t) (hdr + 1);
}

static void mabort __P ((enum mcheck_status status));
static void
mabort (status)
     enum mcheck_status status;
{
  const char *msg;
  switch (status)
    {
    case MCHECK_OK:
      msg = _("memory is consistent, library is buggy\n");
      break;
    case MCHECK_HEAD:
      msg = _("memory clobbered before allocated block\n");
      break;
    case MCHECK_TAIL:
      msg = _("memory clobbered past end of allocated block\n");
      break;
    case MCHECK_FREE:
      msg = _("block freed twice\n");
      break;
    default:
      msg = _("bogus mcheck_status, library is buggy\n");
      break;
    }
#ifdef _LIBC
  __libc_fatal (msg);
#else
  fprintf (stderr, "mcheck: %s", msg);
  fflush (stderr);
  abort ();
#endif
}

static int mcheck_used;

int
mcheck (func)
     void (*func) __P ((enum mcheck_status));
{
  abortfunc = (func != NULL) ? func : &mabort;

  /* These hooks may not be safely inserted if malloc is already in use.  */
  if (__malloc_initialized <= 0 && !mcheck_used)
    {
      old_free_hook = __free_hook;
      __free_hook = freehook;
      old_malloc_hook = __malloc_hook;
      __malloc_hook = mallochook;
      old_realloc_hook = __realloc_hook;
      __realloc_hook = reallochook;
      mcheck_used = 1;
    }

  return mcheck_used ? 0 : -1;
}

enum mcheck_status
mprobe (__ptr_t ptr)
{
  return mcheck_used ? checkhdr (((struct hdr *) ptr) - 1) : MCHECK_DISABLED;
}
Commit	Line	Data
6d52618b	1	/* Standard debugging hooks for `malloc'.
c4563d2d	2	Copyright (C) 1990,91,92,93,94,95,96,97,99 Free Software Foundation, Inc.
6d52618b UD	3	Written May 1989 by Mike Haertel.
	4
	5	This library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Library General Public License as
	7	published by the Free Software Foundation; either version 2 of the
	8	License, or (at your option) any later version.
	9
	10	This library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Library General Public License for more details.
	14
	15	You should have received a copy of the GNU Library General Public
	16	License along with this library; see the file COPYING.LIB. If not,
	17	write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	18	Boston, MA 02111-1307, USA.
	19
	20	The author may be reached (Email) at the address mike@ai.mit.edu,
	21	or (US mail) as Mike Haertel c/o Free Software Foundation. */
	22
	23	#ifndef _MALLOC_INTERNAL
9756dfe1 UD	24	# define _MALLOC_INTERNAL
	25	# include <malloc.h>
	26	# include <mcheck.h>
	27	# include <stdio.h>
6d52618b UD	28	#endif
	29
	30	/* Old hook values. */
a2b08ee5 UD	31	static void (*old_free_hook) __P ((__ptr_t ptr, __const __ptr_t));
	32	static __ptr_t (*old_malloc_hook) __P ((__malloc_size_t size, const __ptr_t));
	33	static __ptr_t (*old_realloc_hook) __P ((__ptr_t ptr, __malloc_size_t size,
	34	__const __ptr_t));
6d52618b UD	35
	36	/* Function to call when something awful happens. */
	37	static void (*abortfunc) __P ((enum mcheck_status));
	38
	39	/* Arbitrary magical numbers. */
	40	#define MAGICWORD 0xfedabeeb
	41	#define MAGICFREE 0xd8675309
	42	#define MAGICBYTE ((char) 0xd7)
	43	#define MALLOCFLOOD ((char) 0x93)
	44	#define FREEFLOOD ((char) 0x95)
	45
	46	struct hdr
	47	{
	48	__malloc_size_t size; /* Exact size requested by user. */
	49	unsigned long int magic; /* Magic number to check header integrity. */
	50	};
	51
9756dfe1 UD	52	#if defined _LIBC \|\| defined STDC_HEADERS \|\| defined USG
	53	# include <string.h>
	54	# define flood memset
6d52618b UD	55	#else
	56	static void flood __P ((__ptr_t, int, __malloc_size_t));
	57	static void
	58	flood (ptr, val, size)
	59	__ptr_t ptr;
	60	int val;
	61	__malloc_size_t size;
	62	{
	63	char *cp = ptr;
	64	while (size--)
	65	*cp++ = val;
	66	}
	67	#endif
	68
	69	static enum mcheck_status checkhdr __P ((const struct hdr *));
	70	static enum mcheck_status
	71	checkhdr (hdr)
	72	const struct hdr *hdr;
	73	{
	74	enum mcheck_status status;
	75	switch (hdr->magic)
	76	{
	77	default:
	78	status = MCHECK_HEAD;
	79	break;
	80	case MAGICFREE:
	81	status = MCHECK_FREE;
	82	break;
	83	case MAGICWORD:
	84	if (((char *) &hdr[1])[hdr->size] != MAGICBYTE)
	85	status = MCHECK_TAIL;
	86	else
	87	status = MCHECK_OK;
	88	break;
	89	}
	90	if (status != MCHECK_OK)
	91	(*abortfunc) (status);
	92	return status;
	93	}
	94
a2b08ee5	95	static void freehook __P ((__ptr_t, const __ptr_t));
6d52618b	96	static void
a2b08ee5	97	freehook (ptr, caller)
6d52618b	98	__ptr_t ptr;
a2b08ee5	99	const __ptr_t caller;
6d52618b UD	100	{
	101	if (ptr)
	102	{
	103	struct hdr hdr = ((struct hdr ) ptr) - 1;
	104	checkhdr (hdr);
	105	hdr->magic = MAGICFREE;
	106	flood (ptr, FREEFLOOD, hdr->size);
	107	ptr = (__ptr_t) hdr;
	108	}
	109	__free_hook = old_free_hook;
a2b08ee5 UD	110	if (old_free_hook != NULL)
	111	(*old_free_hook) (ptr, caller);
	112	else
	113	free (ptr);
6d52618b UD	114	__free_hook = freehook;
	115	}
	116
a2b08ee5	117	static __ptr_t mallochook __P ((__malloc_size_t, const __ptr_t));
6d52618b	118	static __ptr_t
a2b08ee5	119	mallochook (size, caller)
6d52618b	120	__malloc_size_t size;
a2b08ee5	121	const __ptr_t caller;
6d52618b UD	122	{
	123	struct hdr *hdr;
	124
	125	__malloc_hook = old_malloc_hook;
a2b08ee5 UD	126	if (old_malloc_hook != NULL)
	127	hdr = (struct hdr ) (old_malloc_hook) (sizeof (struct hdr) + size + 1,
	128	caller);
	129	else
	130	hdr = (struct hdr *) malloc (sizeof (struct hdr) + size + 1);
6d52618b UD	131	__malloc_hook = mallochook;
	132	if (hdr == NULL)
	133	return NULL;
	134
	135	hdr->size = size;
	136	hdr->magic = MAGICWORD;
	137	((char *) &hdr[1])[size] = MAGICBYTE;
	138	flood ((__ptr_t) (hdr + 1), MALLOCFLOOD, size);
	139	return (__ptr_t) (hdr + 1);
	140	}
	141
a2b08ee5	142	static __ptr_t reallochook __P ((__ptr_t, __malloc_size_t, const __ptr_t));
6d52618b	143	static __ptr_t
a2b08ee5	144	reallochook (ptr, size, caller)
6d52618b UD	145	__ptr_t ptr;
6d52618b UD	146	__malloc_size_t size;
a2b08ee5	147	const __ptr_t caller;
6d52618b UD	148	{
	149	struct hdr *hdr;
	150	__malloc_size_t osize;
	151
	152	if (ptr)
	153	{
	154	hdr = ((struct hdr *) ptr) - 1;
	155	osize = hdr->size;
	156
	157	checkhdr (hdr);
	158	if (size < osize)
	159	flood ((char *) ptr + size, FREEFLOOD, osize - size);
	160	}
	161	else
	162	{
	163	osize = 0;
	164	hdr = NULL;
	165	}
	166	__free_hook = old_free_hook;
	167	__malloc_hook = old_malloc_hook;
	168	__realloc_hook = old_realloc_hook;
a2b08ee5 UD	169	if (old_realloc_hook != NULL)
	170	hdr = (struct hdr ) (old_realloc_hook) ((__ptr_t) hdr,
	171	sizeof (struct hdr) + size + 1,
	172	caller);
	173	else
	174	hdr = (struct hdr *) realloc ((__ptr_t) hdr,
	175	sizeof (struct hdr) + size + 1);
6d52618b UD	176	__free_hook = freehook;
	177	__malloc_hook = mallochook;
	178	__realloc_hook = reallochook;
	179	if (hdr == NULL)
	180	return NULL;
	181
	182	hdr->size = size;
	183	hdr->magic = MAGICWORD;
	184	((char *) &hdr[1])[size] = MAGICBYTE;
	185	if (size > osize)
	186	flood ((char *) (hdr + 1) + osize, MALLOCFLOOD, size - osize);
	187	return (__ptr_t) (hdr + 1);
	188	}
	189
	190	static void mabort __P ((enum mcheck_status status));
	191	static void
	192	mabort (status)
	193	enum mcheck_status status;
	194	{
	195	const char *msg;
	196	switch (status)
	197	{
	198	case MCHECK_OK:
9756dfe1	199	msg = _("memory is consistent, library is buggy\n");
6d52618b UD	200	break;
6d52618b UD	201	case MCHECK_HEAD:
9756dfe1	202	msg = _("memory clobbered before allocated block\n");
6d52618b UD	203	break;
6d52618b UD	204	case MCHECK_TAIL:
9756dfe1	205	msg = _("memory clobbered past end of allocated block\n");
6d52618b UD	206	break;
6d52618b UD	207	case MCHECK_FREE:
9756dfe1	208	msg = _("block freed twice\n");
6d52618b UD	209	break;
6d52618b UD	210	default:
9756dfe1	211	msg = _("bogus mcheck_status, library is buggy\n");
6d52618b UD	212	break;
	213	}
	214	#ifdef _LIBC
	215	__libc_fatal (msg);
	216	#else
9756dfe1	217	fprintf (stderr, "mcheck: %s", msg);
6d52618b UD	218	fflush (stderr);
	219	abort ();
	220	#endif
	221	}
	222
c4563d2d	223	static int mcheck_used;
6d52618b UD	224
	225	int
	226	mcheck (func)
	227	void (*func) __P ((enum mcheck_status));
	228	{
	229	abortfunc = (func != NULL) ? func : &mabort;
	230
	231	/* These hooks may not be safely inserted if malloc is already in use. */
9756dfe1	232	if (__malloc_initialized <= 0 && !mcheck_used)
6d52618b UD	233	{
	234	old_free_hook = __free_hook;
	235	__free_hook = freehook;
	236	old_malloc_hook = __malloc_hook;
	237	__malloc_hook = mallochook;
	238	old_realloc_hook = __realloc_hook;
	239	__realloc_hook = reallochook;
	240	mcheck_used = 1;
	241	}
	242
	243	return mcheck_used ? 0 : -1;
	244	}
	245
	246	enum mcheck_status
	247	mprobe (__ptr_t ptr)
	248	{
997a4165	249	return mcheck_used ? checkhdr (((struct hdr *) ptr) - 1) : MCHECK_DISABLED;
6d52618b	250	}