Index: head/include/stdlib.h
===================================================================
--- head/include/stdlib.h	(revision 282313)
+++ head/include/stdlib.h	(revision 282314)
@@ -1,326 +1,329 @@
 /*-
  * Copyright (c) 1990, 1993
  *	The Regents of the University of California.  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.
  * 3. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
  * 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.
  *
  *	@(#)stdlib.h	8.5 (Berkeley) 5/19/95
  * $FreeBSD$
  */
 
 #ifndef _STDLIB_H_
 #define	_STDLIB_H_
 
 #include <sys/cdefs.h>
 #include <sys/_null.h>
 #include <sys/_types.h>
 
 #if __BSD_VISIBLE
 #ifndef _RUNE_T_DECLARED
 typedef	__rune_t	rune_t;
 #define	_RUNE_T_DECLARED
 #endif
 #endif
 
 #ifndef _SIZE_T_DECLARED
 typedef	__size_t	size_t;
 #define	_SIZE_T_DECLARED
 #endif
 
 #ifndef	__cplusplus
 #ifndef _WCHAR_T_DECLARED
 typedef	___wchar_t	wchar_t;
 #define	_WCHAR_T_DECLARED
 #endif
 #endif
 
 typedef struct {
 	int	quot;		/* quotient */
 	int	rem;		/* remainder */
 } div_t;
 
 typedef struct {
 	long	quot;
 	long	rem;
 } ldiv_t;
 
 #define	EXIT_FAILURE	1
 #define	EXIT_SUCCESS	0
 
 #define	RAND_MAX	0x7ffffffd
 
 __BEGIN_DECLS
 #ifdef _XLOCALE_H_
 #include <xlocale/_stdlib.h>
 #endif
 extern int __mb_cur_max;
 extern int ___mb_cur_max(void);
 #define	MB_CUR_MAX	(___mb_cur_max())
 
 _Noreturn void	 abort(void);
 int	 abs(int) __pure2;
 int	 atexit(void (*)(void));
 double	 atof(const char *);
 int	 atoi(const char *);
 long	 atol(const char *);
 void	*bsearch(const void *, const void *, size_t,
 	    size_t, int (*)(const void *, const void *));
 void	*calloc(size_t, size_t) __malloc_like __result_use_check
 	     __alloc_size(1) __alloc_size(2);
 div_t	 div(int, int) __pure2;
 _Noreturn void	 exit(int);
 void	 free(void *);
 char	*getenv(const char *);
 long	 labs(long) __pure2;
 ldiv_t	 ldiv(long, long) __pure2;
 void	*malloc(size_t) __malloc_like __result_use_check __alloc_size(1);
 int	 mblen(const char *, size_t);
 size_t	 mbstowcs(wchar_t * __restrict , const char * __restrict, size_t);
 int	 mbtowc(wchar_t * __restrict, const char * __restrict, size_t);
 void	 qsort(void *, size_t, size_t,
 	    int (*)(const void *, const void *));
 int	 rand(void);
 void	*realloc(void *, size_t) __result_use_check __alloc_size(2);
 void	 srand(unsigned);
 double	 strtod(const char * __restrict, char ** __restrict);
 float	 strtof(const char * __restrict, char ** __restrict);
 long	 strtol(const char * __restrict, char ** __restrict, int);
 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);
 
 /*
  * Functions added in C99 which we make conditionally available in the
  * BSD^C89 namespace if the compiler supports `long long'.
  * The #if test is more complicated than it ought to be because
  * __BSD_VISIBLE implies __ISO_C_VISIBLE == 1999 *even if* `long long'
  * is not supported in the compilation environment (which therefore means
  * that it can't really be ISO C99).
  *
  * (The only other extension made by C99 in thie header is _Exit().)
  */
 #if __ISO_C_VISIBLE >= 1999
 #ifdef __LONG_LONG_SUPPORTED
 /* LONGLONG */
 typedef struct {
 	long long quot;
 	long long rem;
 } lldiv_t;
 
 /* LONGLONG */
 long long
 	 atoll(const char *);
 /* LONGLONG */
 long long
 	 llabs(long long) __pure2;
 /* LONGLONG */
 lldiv_t	 lldiv(long long, long long) __pure2;
 /* LONGLONG */
 long long
 	 strtoll(const char * __restrict, char ** __restrict, int);
 /* LONGLONG */
 unsigned long long
 	 strtoull(const char * __restrict, char ** __restrict, int);
 #endif /* __LONG_LONG_SUPPORTED */
 
 _Noreturn void	 _Exit(int);
 #endif /* __ISO_C_VISIBLE >= 1999 */
 
 /*
  * If we're in a mode greater than C99, expose C11 functions.
  */
 #if __ISO_C_VISIBLE >= 2011 || __cplusplus >= 201103L
 void *	aligned_alloc(size_t, size_t) __malloc_like __alloc_size(2);
 int	at_quick_exit(void (*)(void));
 _Noreturn void
 	quick_exit(int);
 #endif /* __ISO_C_VISIBLE >= 2011 */
 /*
  * Extensions made by POSIX relative to C.
  */
 #if __POSIX_VISIBLE >= 199506 || __XSI_VISIBLE
 char	*realpath(const char * __restrict, char * __restrict);
 #endif
 #if __POSIX_VISIBLE >= 199506
 int	 rand_r(unsigned *);			/* (TSF) */
 #endif
 #if __POSIX_VISIBLE >= 200112
 int	 posix_memalign(void **, size_t, size_t) __nonnull(1)
 	    __alloc_size(3);			/* (ADV) */
 int	 setenv(const char *, const char *, int);
 int	 unsetenv(const char *);
 #endif
 
 #if __POSIX_VISIBLE >= 200809 || __XSI_VISIBLE
 int	 getsubopt(char **, char *const *, char **);
 #ifndef _MKDTEMP_DECLARED
 char	*mkdtemp(char *);
 #define	_MKDTEMP_DECLARED
 #endif
 #ifndef _MKSTEMP_DECLARED
 int	 mkstemp(char *);
 #define	_MKSTEMP_DECLARED
 #endif
 #endif /* __POSIX_VISIBLE >= 200809 || __XSI_VISIBLE */
 
 /*
  * The only changes to the XSI namespace in revision 6 were the deletion
  * of the ttyslot() and valloc() functions, which FreeBSD never declared
  * in this header.  For revision 7, ecvt(), fcvt(), and gcvt(), which
  * FreeBSD also does not have, and mktemp(), are to be deleted.
  */
 #if __XSI_VISIBLE
 /* XXX XSI requires pollution from <sys/wait.h> here.  We'd rather not. */
 long	 a64l(const char *);
 double	 drand48(void);
 /* char	*ecvt(double, int, int * __restrict, int * __restrict); */
 double	 erand48(unsigned short[3]);
 /* char	*fcvt(double, int, int * __restrict, int * __restrict); */
 /* char	*gcvt(double, int, int * __restrict, int * __restrict); */
 int	 grantpt(int);
 char	*initstate(unsigned long /* XSI requires u_int */, char *, long);
 long	 jrand48(unsigned short[3]);
 char	*l64a(long);
 void	 lcong48(unsigned short[7]);
 long	 lrand48(void);
 #if !defined(_MKTEMP_DECLARED) && (__BSD_VISIBLE || __XSI_VISIBLE <= 600)
 char	*mktemp(char *);
 #define	_MKTEMP_DECLARED
 #endif
 long	 mrand48(void);
 long	 nrand48(unsigned short[3]);
 int	 posix_openpt(int);
 char	*ptsname(int);
 int	 putenv(char *);
 long	 random(void);
 unsigned short
 	*seed48(unsigned short[3]);
 #ifndef _SETKEY_DECLARED
 int	 setkey(const char *);
 #define	_SETKEY_DECLARED
 #endif
 char	*setstate(/* const */ char *);
 void	 srand48(long);
 void	 srandom(unsigned long);
 int	 unlockpt(int);
 #endif /* __XSI_VISIBLE */
 
 #if __BSD_VISIBLE
 extern const char *malloc_conf;
 extern void (*malloc_message)(void *, const char *);
 
 /*
  * The alloca() function can't be implemented in C, and on some
  * platforms it can't be implemented at all as a callable function.
  * The GNU C compiler provides a built-in alloca() which we can use;
  * in all other cases, provide a prototype, mainly to pacify various
  * incarnations of lint.  On platforms where alloca() is not in libc,
  * programs which use it will fail to link when compiled with non-GNU
  * compilers.
  */
 #if __GNUC__ >= 2 || defined(__INTEL_COMPILER)
 #undef  alloca	/* some GNU bits try to get cute and define this on their own */
 #define alloca(sz) __builtin_alloca(sz)
 #elif defined(lint)
 void	*alloca(size_t);
 #endif
 
 void	 abort2(const char *, int, void **) __dead2;
 __uint32_t
 	 arc4random(void);
 void	 arc4random_addrandom(unsigned char *, int);
 void	 arc4random_buf(void *, size_t);
 void	 arc4random_stir(void);
 __uint32_t 
 	 arc4random_uniform(__uint32_t);
 #ifdef __BLOCKS__
 int	 atexit_b(void (^)(void));
 void	*bsearch_b(const void *, const void *, size_t,
 	    size_t, int (^)(const void *, const void *));
 #endif
 char	*getbsize(int *, long *);
 					/* getcap(3) functions */
 char	*cgetcap(char *, const char *, int);
 int	 cgetclose(void);
 int	 cgetent(char **, char **, const char *);
 int	 cgetfirst(char **, char **);
 int	 cgetmatch(const char *, const char *);
 int	 cgetnext(char **, char **);
 int	 cgetnum(char *, const char *, long *);
 int	 cgetset(const char *);
 int	 cgetstr(char *, const char *, char **);
 int	 cgetustr(char *, const char *, char **);
 
 int	 daemon(int, int);
 char	*devname(__dev_t, __mode_t);
 char	*devname_r(__dev_t, __mode_t, char *, int);
 char	*fdevname(int);
 char	*fdevname_r(int, char *, int);
 int	 getloadavg(double [], int);
 const char *
 	 getprogname(void);
 
 int	 heapsort(void *, size_t, size_t, int (*)(const void *, const void *));
 #ifdef __BLOCKS__
 int	 heapsort_b(void *, size_t, size_t, int (^)(const void *, const void *));
 void	 qsort_b(void *, size_t, size_t,
 	    int (^)(const void *, const void *));
 #endif
 int	 l64a_r(long, char *, int);
 int	 mergesort(void *, size_t, size_t, int (*)(const void *, const void *));
 #ifdef __BLOCKS__
 int	 mergesort_b(void *, size_t, size_t, int (^)(const void *, const void *));
 #endif
 int	 mkostemp(char *, int);
 int	 mkostemps(char *, int, int);
 void	 qsort_r(void *, size_t, size_t, void *,
 	    int (*)(void *, const void *, const void *));
 int	 radixsort(const unsigned char **, int, const unsigned char *,
 	    unsigned);
 void	*reallocf(void *, size_t) __result_use_check __alloc_size(2);
 int	 rpmatch(const char *);
 void	 setprogname(const char *);
 int	 sradixsort(const unsigned char **, int, const unsigned char *,
 	    unsigned);
 void	 sranddev(void);
 void	 srandomdev(void);
 long long
 	strtonum(const char *, long long, long long, const char **);
 
 /* Deprecated interfaces, to be removed in FreeBSD 6.0. */
 __int64_t
 	 strtoq(const char *, char **, int);
 __uint64_t
 	 strtouq(const char *, char **, int);
 
 extern char *suboptarg;			/* getsubopt(3) external variable */
 #endif /* __BSD_VISIBLE */
 __END_DECLS
 
 #endif /* !_STDLIB_H_ */
Index: head/lib/libc/stdlib/Makefile.inc
===================================================================
--- head/lib/libc/stdlib/Makefile.inc	(revision 282313)
+++ head/lib/libc/stdlib/Makefile.inc	(revision 282314)
@@ -1,51 +1,52 @@
 #	from @(#)Makefile.inc	8.3 (Berkeley) 2/4/95
 # $FreeBSD$
 
 # machine-independent stdlib sources
 .PATH: ${LIBC_SRCTOP}/${LIBC_ARCH}/stdlib ${LIBC_SRCTOP}/stdlib
 
 MISRCS+=_Exit.c a64l.c abort.c abs.c atexit.c atof.c atoi.c atol.c atoll.c \
 	bsearch.c div.c exit.c getenv.c getopt.c getopt_long.c \
 	getsubopt.c hcreate.c heapsort.c heapsort_b.c imaxabs.c imaxdiv.c \
 	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
 
 SYM_MAPS+= ${LIBC_SRCTOP}/stdlib/Symbol.map
 
 # machine-dependent stdlib sources
 .sinclude "${LIBC_SRCTOP}/${LIBC_ARCH}/stdlib/Makefile.inc"
 
 MAN+=	a64l.3 abort.3 abs.3 alloca.3 atexit.3 atof.3 \
 	atoi.3 atol.3 at_quick_exit.3 bsearch.3 \
 	div.3 exit.3 getenv.3 getopt.3 getopt_long.3 getsubopt.3 \
 	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
 
 MLINKS+=a64l.3 l64a.3 a64l.3 l64a_r.3
 MLINKS+=atol.3 atoll.3
 MLINKS+=exit.3 _Exit.3
 MLINKS+=getenv.3 putenv.3 getenv.3 setenv.3 getenv.3 unsetenv.3
 MLINKS+=getopt_long.3 getopt_long_only.3
 MLINKS+=hcreate.3 hdestroy.3 hcreate.3 hsearch.3
 MLINKS+=hcreate.3 hcreate_r.3 hcreate.3 hdestroy_r.3 hcreate.3 hsearch_r.3
 MLINKS+=insque.3 remque.3
 MLINKS+=lsearch.3 lfind.3
 MLINKS+=ptsname.3 grantpt.3 ptsname.3 unlockpt.3
 MLINKS+=qsort.3 heapsort.3 qsort.3 mergesort.3 qsort.3 qsort_r.3
 MLINKS+=rand.3 rand_r.3 rand.3 srand.3 rand.3 sranddev.3
 MLINKS+=random.3 initstate.3 random.3 setstate.3 random.3 srandom.3 \
 	random.3 srandomdev.3
 MLINKS+=radixsort.3 sradixsort.3
 MLINKS+=strfmon.3 strfmon_l.3
 MLINKS+=strtod.3 strtof.3 strtod.3 strtold.3
 MLINKS+=strtol.3 strtoll.3 strtol.3 strtoq.3 strtol.3 strtoimax.3
 MLINKS+=strtoul.3 strtoull.3 strtoul.3 strtouq.3 strtoul.3 strtoumax.3
 MLINKS+=tsearch.3 tdelete.3 tsearch.3 tfind.3 tsearch.3 twalk.3
Index: head/lib/libc/stdlib/Symbol.map
===================================================================
--- head/lib/libc/stdlib/Symbol.map	(revision 282313)
+++ head/lib/libc/stdlib/Symbol.map	(revision 282314)
@@ -1,122 +1,123 @@
 /*
  * $FreeBSD$
  */
 
 FBSD_1.0 {
 	_Exit;
 	a64l;
 	abort;
 	abs;
 	atexit;
 	__cxa_atexit;
 	__cxa_finalize;
 	atof;
 	atoi;
 	atol;
 	atoll;
 	bsearch;
 	div;
 	__isthreaded;
 	exit;
 	getenv;
 	opterr;
 	optind;
 	optopt;
 	optreset;
 	optarg;
 	getopt;
 	getopt_long;
 	getopt_long_only;
 	suboptarg;
 	getsubopt;
 	grantpt;
 	ptsname;
 	unlockpt;
 	hcreate;
 	hdestroy;
 	hsearch;
 	heapsort;
 	imaxabs;
 	imaxdiv;
 	insque;
 	l64a;
 	l64a_r;
 	labs;
 	ldiv;
 	llabs;
 	lldiv;
 	lsearch;
 	lfind;
 	mergesort;
 	putenv;
 	qsort_r;
 	qsort;
 	radixsort;
 	sradixsort;
 	rand_r;
 	rand;
 	srand;
 	sranddev;
 	srandom;
 	srandomdev;
 	initstate;
 	setstate;
 	random;
 	reallocf;
 	realpath;
 	remque;
 	setenv;
 	unsetenv;
 	strfmon;
 	strtoimax;
 	strtol;
 	strtoll;
 	strtonum;
 	strtoq;
 	strtoul;
 	strtoull;
 	strtoumax;
 	strtouq;
 	system;
 	tdelete;
 	tfind;
 	tsearch;
 	twalk;
 };
 
 FBSD_1.3 {
 	at_quick_exit;
 	atof_l;
 	atoi_l;
 	atol_l;
 	atoll_l;
 	quick_exit;
 	strtod_l;
 	strtof_l;
 	strtoimax_l;
 	strtol_l;
 	strtold_l;
 	strtoll_l;
 	strtoq_l;
 	strtoul_l;
 	strtoull_l;
 	strtoumax_l;
 	strtouq_l;
 };
 
 FBSD_1.4 {
 	atexit_b;
 	bsearch_b;
 	heapsort_b;
 	mergesort_b;
 	qsort_b;
 	hcreate_r;
 	hdestroy_r;
 	hsearch_r;
+	reallocarray;
 };
 
 FBSDprivate_1.0 {
 	__system;
 	_system;
 	__libc_system;
 };
Index: head/lib/libc/stdlib/reallocarray.3
===================================================================
--- head/lib/libc/stdlib/reallocarray.3	(nonexistent)
+++ head/lib/libc/stdlib/reallocarray.3	(revision 282314)
@@ -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 .

Property changes on: head/lib/libc/stdlib/reallocarray.3
___________________________________________________________________
Added: svn:eol-style
## -0,0 +1 ##
+native
\ No newline at end of property
Added: svn:keywords
## -0,0 +1 ##
+FreeBSD=%H
\ No newline at end of property
Added: svn:mime-type
## -0,0 +1 ##
+text/plain
\ No newline at end of property
Index: head/lib/libc/stdlib/reallocarray.c
===================================================================
--- head/lib/libc/stdlib/reallocarray.c	(nonexistent)
+++ head/lib/libc/stdlib/reallocarray.c	(revision 282314)
@@ -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));
+}

Property changes on: head/lib/libc/stdlib/reallocarray.c
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+native
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