diff options
Diffstat (limited to 'openbsd-compat/recallocarray.c')
-rw-r--r-- | openbsd-compat/recallocarray.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/openbsd-compat/recallocarray.c b/openbsd-compat/recallocarray.c new file mode 100644 index 0000000..5d2f8d9 --- /dev/null +++ b/openbsd-compat/recallocarray.c | |||
@@ -0,0 +1,91 @@ | |||
1 | /* $OpenBSD: recallocarray.c,v 1.1 2017/03/06 18:44:21 otto Exp $ */ | ||
2 | /* | ||
3 | * Copyright (c) 2008, 2017 Otto Moerbeek <otto@drijf.net> | ||
4 | * | ||
5 | * Permission to use, copy, modify, and distribute this software for any | ||
6 | * purpose with or without fee is hereby granted, provided that the above | ||
7 | * copyright notice and this permission notice appear in all copies. | ||
8 | * | ||
9 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES | ||
10 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF | ||
11 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR | ||
12 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES | ||
13 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN | ||
14 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF | ||
15 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. | ||
16 | */ | ||
17 | |||
18 | /* OPENBSD ORIGINAL: lib/libc/stdlib/recallocarray.c */ | ||
19 | |||
20 | #include "openbsd-compat.h" | ||
21 | |||
22 | #if !defined(HAVE_RECALLOCARRAY) | ||
23 | |||
24 | #include <errno.h> | ||
25 | #include <stdlib.h> | ||
26 | #include <stdint.h> | ||
27 | #include <string.h> | ||
28 | #ifdef HAVE_UNISTD_H | ||
29 | #include <unistd.h> | ||
30 | #endif | ||
31 | |||
32 | /* | ||
33 | * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX | ||
34 | * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW | ||
35 | */ | ||
36 | #define MUL_NO_OVERFLOW ((size_t)1 << (sizeof(size_t) * 4)) | ||
37 | |||
38 | void * | ||
39 | recallocarray(void *ptr, size_t oldnmemb, size_t newnmemb, size_t size) | ||
40 | { | ||
41 | size_t oldsize, newsize; | ||
42 | void *newptr; | ||
43 | |||
44 | if (ptr == NULL) | ||
45 | return calloc(newnmemb, size); | ||
46 | |||
47 | if ((newnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && | ||
48 | newnmemb > 0 && SIZE_MAX / newnmemb < size) { | ||
49 | errno = ENOMEM; | ||
50 | return NULL; | ||
51 | } | ||
52 | newsize = newnmemb * size; | ||
53 | |||
54 | if ((oldnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && | ||
55 | oldnmemb > 0 && SIZE_MAX / oldnmemb < size) { | ||
56 | errno = EINVAL; | ||
57 | return NULL; | ||
58 | } | ||
59 | oldsize = oldnmemb * size; | ||
60 | |||
61 | /* | ||
62 | * Don't bother too much if we're shrinking just a bit, | ||
63 | * we do not shrink for series of small steps, oh well. | ||
64 | */ | ||
65 | if (newsize <= oldsize) { | ||
66 | size_t d = oldsize - newsize; | ||
67 | |||
68 | if (d < oldsize / 2 && d < (size_t)getpagesize()) { | ||
69 | memset((char *)ptr + newsize, 0, d); | ||
70 | return ptr; | ||
71 | } | ||
72 | } | ||
73 | |||
74 | newptr = malloc(newsize); | ||
75 | if (newptr == NULL) | ||
76 | return NULL; | ||
77 | |||
78 | if (newsize > oldsize) { | ||
79 | memcpy(newptr, ptr, oldsize); | ||
80 | memset((char *)newptr + oldsize, 0, newsize - oldsize); | ||
81 | } else | ||
82 | memcpy(newptr, ptr, newsize); | ||
83 | |||
84 | explicit_bzero(ptr, oldsize); | ||
85 | free(ptr); | ||
86 | |||
87 | return newptr; | ||
88 | } | ||
89 | /* DEF_WEAK(recallocarray); */ | ||
90 | |||
91 | #endif /* !defined(HAVE_RECALLOCARRAY) */ | ||