kc3-lang/libbsd/src/reallocarray.c

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• Hash : 9688ab26
  Author :
  Date : 2014-12-13T08:55:59
  

  Avoid left shift overflow in reallocarray
  
  Some 64-bit platforms (e.g. Windows 64) have a 32-bit long. So, shifting
  1UL 32-bits to the left causes an overflow. This replaces the constant
  1UL with (size_t)1 so that we get the correct constant size for the
  platform.
  
  Import from OpenBSD.
  
  Signed-off-by: Guillem Jover <guillem@hadrons.org>
  

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• src/reallocarray.c

• /*	$OpenBSD: reallocarray.c,v 1.2 2014/12/08 03:45:00 bcook Exp $	*/
  /*
   * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
   *
   * Permission to use, copy, modify, and distribute this software for any
   * purpose with or without fee is hereby granted, provided that the above
   * copyright notice and this permission notice appear in all copies.
   *
   * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
   * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
   */
  
  #include <sys/types.h>
  #include <errno.h>
  #include <stdint.h>
  #include <stdlib.h>
  
  /*
   * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
   * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
   */
  #define MUL_NO_OVERFLOW ((size_t)1 << (sizeof(size_t) * 4))
  
  void *
  reallocarray(void *optr, size_t nmemb, size_t size)
  {
  	if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
  	    nmemb > 0 && SIZE_MAX / nmemb < size) {
  		errno = ENOMEM;
  		return NULL;
  	}
  	return realloc(optr, size * nmemb);
  }
  

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