Date: Fri, 1 May 2015 18:32:16 +0000 (UTC) From: Baptiste Daroussin <bapt@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r282314 - in head: include lib/libc/stdlib Message-ID: <201505011832.t41IWGSs002284@svn.freebsd.org>
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Author: bapt Date: Fri May 1 18:32:16 2015 New Revision: 282314 URL: https://svnweb.freebsd.org/changeset/base/282314 Log: Import reallocarray(3) from OpenBSD Add a manpage for it, assign the copyright to the OpenBSD project on it since it is mostly copy/paste from OpenBSD manpage. style(9) fixes Differential Revision: https://reviews.freebsd.org/D2420 Reviewed by: kib Added: head/lib/libc/stdlib/reallocarray.3 (contents, props changed) head/lib/libc/stdlib/reallocarray.c (contents, props changed) Modified: head/include/stdlib.h head/lib/libc/stdlib/Makefile.inc head/lib/libc/stdlib/Symbol.map Modified: head/include/stdlib.h ============================================================================== --- head/include/stdlib.h Fri May 1 18:07:18 2015 (r282313) +++ head/include/stdlib.h Fri May 1 18:32:16 2015 (r282314) @@ -111,6 +111,9 @@ long double strtold(const char * __restrict, char ** __restrict); unsigned long strtoul(const char * __restrict, char ** __restrict, int); +#ifdef __BSD_VISIBLE +void *reallocarray(void *, size_t, size_t); +#endif int system(const char *); int wctomb(char *, wchar_t); size_t wcstombs(char * __restrict, const wchar_t * __restrict, size_t); Modified: head/lib/libc/stdlib/Makefile.inc ============================================================================== --- head/lib/libc/stdlib/Makefile.inc Fri May 1 18:07:18 2015 (r282313) +++ head/lib/libc/stdlib/Makefile.inc Fri May 1 18:32:16 2015 (r282314) @@ -10,7 +10,8 @@ MISRCS+=_Exit.c a64l.c abort.c abs.c ate insque.c l64a.c labs.c ldiv.c llabs.c lldiv.c lsearch.c \ merge.c mergesort_b.c ptsname.c qsort.c qsort_r.c quick_exit.c \ radixsort.c rand.c \ - random.c reallocf.c realpath.c remque.c strfmon.c strtoimax.c \ + random.c reallocarray.c reallocf.c realpath.c remque.c strfmon.c \ + strtoimax.c \ strtol.c strtoll.c strtoq.c strtoul.c strtonum.c strtoull.c \ strtoumax.c strtouq.c system.c tdelete.c tfind.c tsearch.c twalk.c @@ -25,7 +26,7 @@ MAN+= a64l.3 abort.3 abs.3 alloca.3 atex hcreate.3 imaxabs.3 imaxdiv.3 insque.3 labs.3 ldiv.3 llabs.3 lldiv.3 \ lsearch.3 memory.3 ptsname.3 qsort.3 \ quick_exit.3 \ - radixsort.3 rand.3 random.3 reallocf.3 \ + radixsort.3 rand.3 random.3 reallocarray.3 reallocf.3 \ realpath.3 strfmon.3 strtod.3 strtol.3 strtonum.3 strtoul.3 system.3 \ tsearch.3 Modified: head/lib/libc/stdlib/Symbol.map ============================================================================== --- head/lib/libc/stdlib/Symbol.map Fri May 1 18:07:18 2015 (r282313) +++ head/lib/libc/stdlib/Symbol.map Fri May 1 18:32:16 2015 (r282314) @@ -113,6 +113,7 @@ FBSD_1.4 { hcreate_r; hdestroy_r; hsearch_r; + reallocarray; }; FBSDprivate_1.0 { Added: head/lib/libc/stdlib/reallocarray.3 ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/lib/libc/stdlib/reallocarray.3 Fri May 1 18:32:16 2015 (r282314) @@ -0,0 +1,136 @@ +.\" Copyright (c) 2015 OpenBSD +.\" All rights reserved. +.\" +.\" This code is derived from software contributed to Berkeley by +.\" the American National Standards Committee X3, on Information +.\" Processing Systems. +.\" +.\" 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 REGENTS 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 REGENTS 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. +.\" +.\" $FreeBSD$ +.\" +.Dd May 1, 2015 +.Dt REALLOCARRAY 3 +.Os +.Sh NAME +.Nm reallocarray +.Nd memory reallocation function +.Sh LIBRARY +.Lb libc +.Sh SYNOPSIS +.In stdlib.h +.Ft void * +.Fn reallocarray "void *ptr" "size_t nmemb" "size_t size" +.Sh DESCRIPTION +The +.Fn reallocarray +except it operates on +.Fa nmemb +members of size +.Fa size +and checks for integer overflow in the calculation +.Fa nmemb +* +.Fa size . +.Sh RETURN VALUES +.Fn reallocarray +return a pointer to the allocated space; otherwise, a +.Dv NULL +pointer is returned and +.Va errno +is set to +.Er ENOMEM . +.Sh EXAMPLES +Consider +.Fn reallocarray +when there is multiplication in the +.Fa size +argument of +.Fn malloc +or +.Fn realloc . +For example, avoid this common idiom as it may lead to integer overflow: +.Bd -literal -offset indent +if ((p = malloc(num * size)) == NULL) + err(1, "malloc"); +.Ed +.Pp +A drop-in replacement is the +.Ox +extension +.Fn reallocarray : +.Bd -literal -offset indent +if ((p = reallocarray(NULL, num, size)) == NULL) + err(1, "reallocarray"); +.Ed +.Pp +When using +.Fn realloc , +be careful to avoid the following idiom: +.Bd -literal -offset indent +size += 50; +if ((p = realloc(p, size)) == NULL) + return (NULL); +.Ed +.Pp +Do not adjust the variable describing how much memory has been allocated +until the allocation has been successful. +This can cause aberrant program behavior if the incorrect size value is used. +In most cases, the above sample will also result in a leak of memory. +As stated earlier, a return value of +.Dv NULL +indicates that the old object still remains allocated. +Better code looks like this: +.Bd -literal -offset indent +newsize = size + 50; +if ((newp = realloc(p, newsize)) == NULL) { + free(p); + p = NULL; + size = 0; + return (NULL); +} +p = newp; +size = newsize; +.Ed +.Pp +As with +.Fn malloc , +it is important to ensure the new size value will not overflow; +i.e. avoid allocations like the following: +.Bd -literal -offset indent +if ((newp = realloc(p, num * size)) == NULL) { + ... +.Ed +.Pp +Instead, use +.Fn reallocarray : +.Bd -literal -offset indent +if ((newp = reallocarray(p, num, size)) == NULL) { + ... +.Ed +.Sh SEE ALSO +.Xr realloc 3 +.Sh HISTORY +The +.Fn reallocf +function first appeared in +.Ox 5.6 . Added: head/lib/libc/stdlib/reallocarray.c ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/lib/libc/stdlib/reallocarray.c Fri May 1 18:32:16 2015 (r282314) @@ -0,0 +1,42 @@ +/* $OpenBSD: reallocarray.c,v 1.2 2014/12/08 03:45:00 bcook Exp $ */ +/* + * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/types.h> +#include <errno.h> +#include <stdint.h> +#include <stdlib.h> + +/* + * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX + * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW + */ +#define MUL_NO_OVERFLOW ((size_t)1 << (sizeof(size_t) * 4)) + +void * +reallocarray(void *optr, size_t nmemb, size_t size) +{ + + if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) && + nmemb > 0 && SIZE_MAX / nmemb < size) { + errno = ENOMEM; + return (NULL); + } + return (realloc(optr, size * nmemb)); +}
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