memory.c

/* Memory allocation routines.

Copyright 1991, 1993, 1994, 2000-2002, 2012 Free Software Foundation, Inc.

This file is part of the GNU MP Library.

The GNU MP Library is free software; you can redistribute it and/or modify
it under the terms of either:

  * the GNU Lesser General Public License as published by the Free
    Software Foundation; either version 3 of the License, or (at your
    option) any later version.

or

  * the GNU General Public License as published by the Free Software
    Foundation; either version 2 of the License, or (at your option) any
    later version.

or both in parallel, as here.

The GNU MP 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 General Public License
for more details.

You should have received copies of the GNU General Public License and the
GNU Lesser General Public License along with the GNU MP Library.  If not,
see https://www.gnu.org/licenses/.  */

#include <stdio.h>
#include <stdlib.h> /* for malloc, realloc, free */

#include "gmp.h"
#include "gmp-impl.h"


void * (*__gmp_allocate_func) (size_t) = __gmp_default_allocate;
void * (*__gmp_reallocate_func) (void *, size_t, size_t) = __gmp_default_reallocate;
void   (*__gmp_free_func) (void *, size_t) = __gmp_default_free;


/* Default allocation functions.  In case of failure to allocate/reallocate
   an error message is written to stderr and the program aborts.  */

void *
__gmp_default_allocate (size_t size)
{
  void *ret;
#ifdef DEBUG
  size_t req_size = size;
  size += 2 * GMP_LIMB_BYTES;
#endif
  ret = malloc (size);
  if (ret == 0)
    {
/* No I/O in an Intel SGX enclave. -John Mechalas <john.p.mechalas@intel.com> */
#ifndef HAVE_SGX
      fprintf (stderr, "GNU MP: Cannot allocate memory (size=%lu)\n", (long) size);
#endif
      abort ();
    }

#ifdef DEBUG
  {
    mp_ptr p = ret;
    p++;
    p[-1] = (0xdeadbeef << 31) + 0xdeafdeed;
    if (req_size % GMP_LIMB_BYTES == 0)
      p[req_size / GMP_LIMB_BYTES] = ~((0xdeadbeef << 31) + 0xdeafdeed);
    ret = p;
  }
#endif
  return ret;
}

void *
__gmp_default_reallocate (void *oldptr, size_t old_size, size_t new_size)
{
  void *ret;

#ifdef DEBUG
  size_t req_size = new_size;

  if (old_size != 0)
    {
      mp_ptr p = oldptr;
      if (p[-1] != (0xdeadbeef << 31) + 0xdeafdeed)
	{
/* No I/O in an Intel SGX enclave. -John Mechalas <john.p.mechalas@intel.com> */
#ifndef HAVE_SGX
	  fprintf (stderr, "gmp: (realloc) data clobbered before allocation block\n");
#endif
      abort ();
	}
      if (old_size % GMP_LIMB_BYTES == 0)
	if (p[old_size / GMP_LIMB_BYTES] != ~((0xdeadbeef << 31) + 0xdeafdeed))
	  {
/* No I/O in an Intel SGX enclave. -John Mechalas <john.p.mechalas@intel.com> */
#ifndef HAVE_SGX
	    fprintf (stderr, "gmp: (realloc) data clobbered after allocation block\n");
#endif
	  	abort ();
	  }
      oldptr = p - 1;
    }

  new_size += 2 * GMP_LIMB_BYTES;
#endif

  ret = realloc (oldptr, new_size);
  if (ret == 0)
    {
/* No I/O in an Intel SGX enclave. -John Mechalas <john.p.mechalas@intel.com> */
#ifndef HAVE_SGX
      fprintf (stderr, "GNU MP: Cannot reallocate memory (old_size=%lu new_size=%lu)\n", (long) old_size, (long) new_size);
#endif
      abort ();
    }

#ifdef DEBUG
  {
    mp_ptr p = ret;
    p++;
    p[-1] = (0xdeadbeef << 31) + 0xdeafdeed;
    if (req_size % GMP_LIMB_BYTES == 0)
      p[req_size / GMP_LIMB_BYTES] = ~((0xdeadbeef << 31) + 0xdeafdeed);
    ret = p;
  }
#endif
  return ret;
}

void
__gmp_default_free (void *blk_ptr, size_t blk_size)
{
#ifdef DEBUG
  {
    mp_ptr p = blk_ptr;
    if (blk_size != 0)
      {
	if (p[-1] != (0xdeadbeef << 31) + 0xdeafdeed)
	  {
/* No I/O in an Intel SGX enclave. -John Mechalas <john.p.mechalas@intel.com> */
#ifndef HAVE_SGX
	    fprintf (stderr, "gmp: (free) data clobbered before allocation block\n");
#endif
	    abort ();
	  }
	if (blk_size % GMP_LIMB_BYTES == 0)
	  if (p[blk_size / GMP_LIMB_BYTES] != ~((0xdeadbeef << 31) + 0xdeafdeed))
	    {
#ifndef HAVE_SGX
	      fprintf (stderr, "gmp: (free) data clobbered after allocation block\n");
#endif
	      abort ();
	    }
      }
    blk_ptr = p - 1;
  }
#endif
  free (blk_ptr);
}