recallocarray.c revision 1.1.1.1.2.2
1 1.1.1.1.2.2 pgoyette /* $OpenBSD: recallocarray.c,v 1.1 2017/03/06 18:44:21 otto Exp $ */ 2 1.1.1.1.2.2 pgoyette /* 3 1.1.1.1.2.2 pgoyette * Copyright (c) 2008, 2017 Otto Moerbeek <otto (at) drijf.net> 4 1.1.1.1.2.2 pgoyette * 5 1.1.1.1.2.2 pgoyette * Permission to use, copy, modify, and distribute this software for any 6 1.1.1.1.2.2 pgoyette * purpose with or without fee is hereby granted, provided that the above 7 1.1.1.1.2.2 pgoyette * copyright notice and this permission notice appear in all copies. 8 1.1.1.1.2.2 pgoyette * 9 1.1.1.1.2.2 pgoyette * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 1.1.1.1.2.2 pgoyette * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 1.1.1.1.2.2 pgoyette * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 1.1.1.1.2.2 pgoyette * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 1.1.1.1.2.2 pgoyette * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 1.1.1.1.2.2 pgoyette * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 1.1.1.1.2.2 pgoyette * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 1.1.1.1.2.2 pgoyette */ 17 1.1.1.1.2.2 pgoyette 18 1.1.1.1.2.2 pgoyette #include <errno.h> 19 1.1.1.1.2.2 pgoyette #include <stdlib.h> 20 1.1.1.1.2.2 pgoyette #include <stdint.h> 21 1.1.1.1.2.2 pgoyette #include <string.h> 22 1.1.1.1.2.2 pgoyette #include <unistd.h> 23 1.1.1.1.2.2 pgoyette 24 1.1.1.1.2.2 pgoyette #include "compat.h" 25 1.1.1.1.2.2 pgoyette 26 1.1.1.1.2.2 pgoyette /* 27 1.1.1.1.2.2 pgoyette * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX 28 1.1.1.1.2.2 pgoyette * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW 29 1.1.1.1.2.2 pgoyette */ 30 1.1.1.1.2.2 pgoyette #define MUL_NO_OVERFLOW ((size_t)1 << (sizeof(size_t) * 4)) 31 1.1.1.1.2.2 pgoyette 32 1.1.1.1.2.2 pgoyette void * 33 1.1.1.1.2.2 pgoyette recallocarray(void *ptr, size_t oldnmemb, size_t newnmemb, size_t size) 34 1.1.1.1.2.2 pgoyette { 35 1.1.1.1.2.2 pgoyette size_t oldsize, newsize; 36 1.1.1.1.2.2 pgoyette void *newptr; 37 1.1.1.1.2.2 pgoyette 38 1.1.1.1.2.2 pgoyette if (ptr == NULL) 39 1.1.1.1.2.2 pgoyette return calloc(newnmemb, size); 40 1.1.1.1.2.2 pgoyette 41 1.1.1.1.2.2 pgoyette if ((newnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && 42 1.1.1.1.2.2 pgoyette newnmemb > 0 && SIZE_MAX / newnmemb < size) { 43 1.1.1.1.2.2 pgoyette errno = ENOMEM; 44 1.1.1.1.2.2 pgoyette return NULL; 45 1.1.1.1.2.2 pgoyette } 46 1.1.1.1.2.2 pgoyette newsize = newnmemb * size; 47 1.1.1.1.2.2 pgoyette 48 1.1.1.1.2.2 pgoyette if ((oldnmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && 49 1.1.1.1.2.2 pgoyette oldnmemb > 0 && SIZE_MAX / oldnmemb < size) { 50 1.1.1.1.2.2 pgoyette errno = EINVAL; 51 1.1.1.1.2.2 pgoyette return NULL; 52 1.1.1.1.2.2 pgoyette } 53 1.1.1.1.2.2 pgoyette oldsize = oldnmemb * size; 54 1.1.1.1.2.2 pgoyette 55 1.1.1.1.2.2 pgoyette /* 56 1.1.1.1.2.2 pgoyette * Don't bother too much if we're shrinking just a bit, 57 1.1.1.1.2.2 pgoyette * we do not shrink for series of small steps, oh well. 58 1.1.1.1.2.2 pgoyette */ 59 1.1.1.1.2.2 pgoyette if (newsize <= oldsize) { 60 1.1.1.1.2.2 pgoyette size_t d = oldsize - newsize; 61 1.1.1.1.2.2 pgoyette 62 1.1.1.1.2.2 pgoyette if (d < oldsize / 2 && d < (size_t)getpagesize()) { 63 1.1.1.1.2.2 pgoyette memset((char *)ptr + newsize, 0, d); 64 1.1.1.1.2.2 pgoyette return ptr; 65 1.1.1.1.2.2 pgoyette } 66 1.1.1.1.2.2 pgoyette } 67 1.1.1.1.2.2 pgoyette 68 1.1.1.1.2.2 pgoyette newptr = malloc(newsize); 69 1.1.1.1.2.2 pgoyette if (newptr == NULL) 70 1.1.1.1.2.2 pgoyette return NULL; 71 1.1.1.1.2.2 pgoyette 72 1.1.1.1.2.2 pgoyette if (newsize > oldsize) { 73 1.1.1.1.2.2 pgoyette memcpy(newptr, ptr, oldsize); 74 1.1.1.1.2.2 pgoyette memset((char *)newptr + oldsize, 0, newsize - oldsize); 75 1.1.1.1.2.2 pgoyette } else 76 1.1.1.1.2.2 pgoyette memcpy(newptr, ptr, newsize); 77 1.1.1.1.2.2 pgoyette 78 1.1.1.1.2.2 pgoyette explicit_bzero(ptr, oldsize); 79 1.1.1.1.2.2 pgoyette free(ptr); 80 1.1.1.1.2.2 pgoyette 81 1.1.1.1.2.2 pgoyette return newptr; 82 1.1.1.1.2.2 pgoyette } 83
Indexes created Thu Apr 02 00:23:07 UTC 2026