memset_s.c 2.5 KB

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  1. /*-
  2. * Copyright (c) 2012 The NetBSD Foundation, Inc.
  3. * All rights reserved.
  4. *
  5. * This code is derived from software contributed to The NetBSD Foundation
  6. * by Alan Barrett
  7. *
  8. * Redistribution and use in source and binary forms, with or without
  9. * modification, are permitted provided that the following conditions
  10. * are met:
  11. * 1. Redistributions of source code must retain the above copyright
  12. * notice, this list of conditions and the following disclaimer.
  13. * 2. Redistributions in binary form must reproduce the above copyright
  14. * notice, this list of conditions and the following disclaimer in the
  15. * documentation and/or other materials provided with the distribution.
  16. *
  17. * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  18. * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  19. * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  20. * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  21. * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  22. * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  23. * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  24. * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  25. * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  26. * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  27. * POSSIBILITY OF SUCH DAMAGE.
  28. */
  29. /*
  30. * ISO/IEC 9899:2011 section K.3.7.4.1 The memset_s function
  31. */
  32. #include <sys/cdefs.h>
  33. #define __STDC_WANT_LIB_EXT1__ 1
  34. #include "errno.h"
  35. #include <stdint.h>
  36. #include <string.h>
  37. /*
  38. * __memset_vp is a volatile pointer to a function.
  39. * It is initialised to point to memset, and should never be changed.
  40. */
  41. static void * (* const volatile __memset_vp)(void *, int, size_t)
  42. = (memset);
  43. #undef memset_s /* in case it was defined as a macro */
  44. errno_t
  45. memset_s(void *s, size_t smax, int c, size_t n)
  46. {
  47. /* errno_t err = 0;
  48. if (s == NULL) {
  49. err = EINVAL;
  50. goto out;
  51. }
  52. if (smax > SIZE_MAX) {
  53. err = E2BIG;
  54. goto out;
  55. }
  56. if (n > SIZE_MAX) {
  57. err = E2BIG;
  58. n = smax;
  59. }
  60. if (n > smax) {
  61. err = EOVERFLOW;
  62. n = smax;
  63. }
  64. // Calling through a volatile pointer should never be optimised away.
  65. (*__memset_vp)(s, c, n);
  66. out:
  67. if (err == 0)
  68. return 0;
  69. else {
  70. errno = err;
  71. // XXX call runtime-constraint handler
  72. return err;
  73. }
  74. */
  75. return 0;
  76. }