diff options
Diffstat (limited to 'openbsd-compat/recallocarray.c')
-rw-r--r-- | openbsd-compat/recallocarray.c | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/openbsd-compat/recallocarray.c b/openbsd-compat/recallocarray.c new file mode 100644 index 000000000..3e1156ce2 --- /dev/null +++ b/openbsd-compat/recallocarray.c | |||
@@ -0,0 +1,90 @@ | |||
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 "includes.h" | ||
21 | #ifndef HAVE_RECALLOCARRAY | ||
22 | |||
23 | #include <errno.h> | ||
24 | #include <stdlib.h> | ||
25 | #ifdef HAVE_STDINT_H | ||
26 | #include <stdint.h> | ||
27 | #endif | ||
28 | #include <string.h> | ||
29 | #include <unistd.h> | ||
30 | |||
31 | /* | ||
32 | * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX | ||
33 | * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW | ||
34 | */ | ||
35 | #define MUL_NO_OVERFLOW ((size_t)1 << (sizeof(size_t) * 4)) | ||
36 | |||
37 | void * | ||
38 | recallocarray(void *ptr, size_t oldnmemb, size_t newnmemb, size_t size) | ||
39 | { | ||
40 | size_t oldsize, newsize; | ||
41 | void *newptr; | ||
42 | |||
43 | if (ptr == NULL) | ||
44 | return calloc(newnmemb, size); | ||
45 | |||
46 | if ((newnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && | ||
47 | newnmemb > 0 && SIZE_MAX / newnmemb < size) { | ||
48 | errno = ENOMEM; | ||
49 | return NULL; | ||
50 | } | ||
51 | newsize = newnmemb * size; | ||
52 | |||
53 | if ((oldnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && | ||
54 | oldnmemb > 0 && SIZE_MAX / oldnmemb < size) { | ||
55 | errno = EINVAL; | ||
56 | return NULL; | ||
57 | } | ||
58 | oldsize = oldnmemb * size; | ||
59 | |||
60 | /* | ||
61 | * Don't bother too much if we're shrinking just a bit, | ||
62 | * we do not shrink for series of small steps, oh well. | ||
63 | */ | ||
64 | if (newsize <= oldsize) { | ||
65 | size_t d = oldsize - newsize; | ||
66 | |||
67 | if (d < oldsize / 2 && d < (size_t)getpagesize()) { | ||
68 | memset((char *)ptr + newsize, 0, d); | ||
69 | return ptr; | ||
70 | } | ||
71 | } | ||
72 | |||
73 | newptr = malloc(newsize); | ||
74 | if (newptr == NULL) | ||
75 | return NULL; | ||
76 | |||
77 | if (newsize > oldsize) { | ||
78 | memcpy(newptr, ptr, oldsize); | ||
79 | memset((char *)newptr + oldsize, 0, newsize - oldsize); | ||
80 | } else | ||
81 | memcpy(newptr, ptr, newsize); | ||
82 | |||
83 | explicit_bzero(ptr, oldsize); | ||
84 | free(ptr); | ||
85 | |||
86 | return newptr; | ||
87 | } | ||
88 | /* DEF_WEAK(recallocarray); */ | ||
89 | |||
90 | #endif /* HAVE_RECALLOCARRAY */ | ||