diff options
Diffstat (limited to 'libc/upstream-netbsd/lib/libc/stdlib/reallocarr.c')
-rw-r--r-- | libc/upstream-netbsd/lib/libc/stdlib/reallocarr.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/libc/upstream-netbsd/lib/libc/stdlib/reallocarr.c b/libc/upstream-netbsd/lib/libc/stdlib/reallocarr.c new file mode 100644 index 000000000..6ffe8114e --- /dev/null +++ b/libc/upstream-netbsd/lib/libc/stdlib/reallocarr.c @@ -0,0 +1,95 @@ +/* $NetBSD: reallocarr.c,v 1.5 2015/08/20 22:27:49 kamil Exp $ */ + +/*- + * Copyright (c) 2015 Joerg Sonnenberger <joerg@NetBSD.org>. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#if HAVE_NBTOOL_CONFIG_H +#include "nbtool_config.h" +#endif + +#include <sys/cdefs.h> +__RCSID("$NetBSD: reallocarr.c,v 1.5 2015/08/20 22:27:49 kamil Exp $"); + +#include "namespace.h" +#include <errno.h> +/* Old POSIX has SIZE_MAX in limits.h */ +#include <limits.h> +#include <stdint.h> +#include <stdlib.h> +#include <string.h> + +#ifdef _LIBC +#ifdef __weak_alias +__weak_alias(reallocarr, _reallocarr) +#endif +#endif + +#define SQRT_SIZE_MAX (((size_t)1) << (sizeof(size_t) * CHAR_BIT / 2)) + +#if !HAVE_REALLOCARR +int +reallocarr(void *ptr, size_t number, size_t size) +{ + int saved_errno, result; + void *optr; + void *nptr; + + saved_errno = errno; + memcpy(&optr, ptr, sizeof(ptr)); + if (number == 0 || size == 0) { + free(optr); + nptr = NULL; + memcpy(ptr, &nptr, sizeof(ptr)); + errno = saved_errno; + return 0; + } + + /* + * Try to avoid division here. + * + * It isn't possible to overflow during multiplication if neither + * operand uses any of the most significant half of the bits. + */ + if (__predict_false((number|size) >= SQRT_SIZE_MAX && + number > SIZE_MAX / size)) { + errno = saved_errno; + return EOVERFLOW; + } + + nptr = realloc(optr, number * size); + if (__predict_false(nptr == NULL)) { + result = errno; + } else { + result = 0; + memcpy(ptr, &nptr, sizeof(ptr)); + } + errno = saved_errno; + return result; +} +#endif |