add posix_madvise, posix_memalign, strndup, and strnlen. mostly from

brad and millert, with hints from guenther, jmc, and otto I think.
ok previous.

14 files changed, 325 insertions, 27 deletions

diff --git a/lib/libc/gen/valloc.3 b/lib/libc/gen/valloc.3
index adb4948d052..cea59620988 100644
--- a/lib/libc/gen/valloc.3
+++ b/lib/libc/gen/valloc.3
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: valloc.3,v 1.12 2007/05/31 19:19:29 jmc Exp $
+.\"	$OpenBSD: valloc.3,v 1.13 2010/05/18 22:24:55 tedu Exp $
 .\"
 .\" Copyright (c) 1980, 1991, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -27,7 +27,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: May 31 2007 $
+.Dd $Mdocdate: May 18 2010 $
 .Dt VALLOC 3
 .Os
 .Sh NAME
@@ -43,7 +43,10 @@ The
 .Fn valloc
 function is obsoleted by the current version of
 .Xr malloc 3 ,
-which aligns page-sized and larger allocations.
+which aligns page-sized and larger allocations,
+and
+.Xr posix_memalign 3 ,
+which allocates memory with a given alignment.
 .Ef
 .Pp
 The
diff --git a/lib/libc/shlib_version b/lib/libc/shlib_version
index b6d2a137e28..81a5aca30f3 100644
--- a/lib/libc/shlib_version
+++ b/lib/libc/shlib_version
@@ -1,4 +1,4 @@
 major=53
-minor=1
+minor=2
 # note: If changes were made to include/thread_private.h or if system
 # calls were added/changed then libpthread must also be updated.
diff --git a/lib/libc/stdlib/Makefile.inc b/lib/libc/stdlib/Makefile.inc
index b003560291f..81d19620261 100644
--- a/lib/libc/stdlib/Makefile.inc
+++ b/lib/libc/stdlib/Makefile.inc
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile.inc,v 1.43 2010/02/03 20:49:00 miod Exp $
+#	$OpenBSD: Makefile.inc,v 1.44 2010/05/18 22:24:55 tedu Exp $
 
 # stdlib sources
 .PATH: ${LIBCSRCDIR}/arch/${MACHINE_CPU}/stdlib ${LIBCSRCDIR}/stdlib
@@ -42,9 +42,9 @@ SRCS+=	insque.c remque.c
 MAN+=	a64l.3 abort.3 abs.3 alloca.3 atexit.3 atof.3 atoi.3 atol.3 atoll.3 \
 	bsearch.3 div.3 ecvt.3 exit.3 getenv.3 getopt.3 getopt_long.3 \
 	getsubopt.3 hcreate.3 imaxabs.3 imaxdiv.3 insque.3 labs.3 ldiv.3 \
-	lldiv.3 lsearch.3 malloc.3 qabs.3 qdiv.3 qsort.3 radixsort.3 rand48.3 \
-	rand.3 random.3 realpath.3 strtod.3 strtonum.3 strtol.3 strtoul.3 \
-	system.3 tsearch.3
+	lldiv.3 lsearch.3 malloc.3 posix_memalign.3 qabs.3 qdiv.3 qsort.3 \
+	radixsort.3 rand48.3 rand.3 random.3 realpath.3 strtod.3 strtonum.3 \
+	strtol.3 strtoul.3 system.3 tsearch.3
 
 MLINKS+=exit.3 _Exit.3
 MLINKS+=ecvt.3 fcvt.3 ecvt.3 gcvt.3
diff --git a/lib/libc/stdlib/malloc.3 b/lib/libc/stdlib/malloc.3
index d30ac8c08ce..62006a7eb5a 100644
--- a/lib/libc/stdlib/malloc.3
+++ b/lib/libc/stdlib/malloc.3
@@ -30,9 +30,9 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"	$OpenBSD: malloc.3,v 1.65 2010/01/25 20:14:11 jmc Exp $
+.\"	$OpenBSD: malloc.3,v 1.66 2010/05/18 22:24:55 tedu Exp $
 .\"
-.Dd $Mdocdate: January 25 2010 $
+.Dd $Mdocdate: May 18 2010 $
 .Dt MALLOC 3
 .Os
 .Sh NAME
@@ -420,7 +420,8 @@ consult sources and/or wizards.
 .Xr mmap 2 ,
 .Xr munmap 2 ,
 .Xr alloca 3 ,
-.Xr getpagesize 3
+.Xr getpagesize 3 ,
+.Xr posix_memalign 3
 .Sh STANDARDS
 The
 .Fn malloc
diff --git a/lib/libc/stdlib/malloc.c b/lib/libc/stdlib/malloc.c
index 9cee3e5935f..902b69c2162 100644
--- a/lib/libc/stdlib/malloc.c
+++ b/lib/libc/stdlib/malloc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: malloc.c,v 1.124 2010/01/13 12:40:11 otto Exp $	*/
+/*	$OpenBSD: malloc.c,v 1.125 2010/05/18 22:24:55 tedu Exp $	*/
 /*
  * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
  *
@@ -1488,3 +1488,28 @@ calloc(size_t nmemb, size_t size)
 	return r;
 }
 
+int
+posix_memalign(void **memptr, size_t alignment, size_t size)
+{
+	void *result;
+
+	/* Make sure that alignment is a large enough power of 2. */
+	if (((alignment - 1) & alignment) != 0 || alignment < sizeof(void *) ||
+	    alignment > MALLOC_PAGESIZE)
+		return EINVAL;
+
+	/* 
+	 * max(size, alignment) is enough to assure the requested alignment,
+	 * since the allocator always allocates power-of-two blocks.
+	 */
+	if (size < alignment)
+		size = alignment;
+	result = malloc(size);
+
+	if (result == NULL)
+		return ENOMEM;
+
+	*memptr = result;
+	return 0;
+}
+
diff --git a/lib/libc/stdlib/posix_memalign.3 b/lib/libc/stdlib/posix_memalign.3
new file mode 100644
index 00000000000..7bd39933dcd
--- /dev/null
+++ b/lib/libc/stdlib/posix_memalign.3
@@ -0,0 +1,94 @@
+.\"	$OpenBSD
+.\" Copyright (C) 2006 Jason Evans <jasone@FreeBSD.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(s), this list of conditions and the following disclaimer as
+.\"    the first lines of this file unmodified other than the possible
+.\"    addition of one or more copyright notices.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice(s), 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 HOLDER(S) ``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 HOLDER(S) 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: src/lib/libc/stdlib/posix_memalign.3,v 1.3 2007/03/28 04:32:51 jasone Exp $
+.\"
+.Dd $Mdocdate: May 18 2010 $
+.Dt POSIX_MEMALIGN 3
+.Os
+.Sh NAME
+.Nm posix_memalign
+.Nd aligned memory allocation
+.Sh SYNOPSIS
+.In stdlib.h
+.Ft int
+.Fn posix_memalign "void **ptr" "size_t alignment" "size_t size"
+.Sh DESCRIPTION
+The
+.Fn posix_memalign
+function allocates
+.Fa size
+bytes of memory such that the allocation's base address is a multiple of
+.Fa alignment ,
+and returns the allocation in the value pointed to by
+.Fa ptr .
+.Pp
+The requested
+.Fa alignment
+must be a power of 2 at least as large as
+.Fn sizeof "void *" .
+.Pp
+Memory that is allocated via
+.Fn posix_memalign
+can be used as an argument in subsequent calls to
+.Xr realloc 3
+and
+.Xr free 3 .
+.Sh RETURN VALUES
+The
+.Fn posix_memalign
+function returns the value 0 if successful; otherwise it returns an error value.
+.Sh ERRORS
+The
+.Fn posix_memalign
+function will fail if:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The
+.Fa alignment
+parameter is not a power of 2 at least as large as
+.Fn sizeof "void *" .
+.It Bq Er ENOMEM
+Memory allocation error.
+.El
+.Sh SEE ALSO
+.Xr free 3 ,
+.Xr malloc 3 ,
+.Xr realloc 3
+.Sh STANDARDS
+The
+.Fn posix_memalign
+function conforms to
+.St -p1003.1-2001 .
+.Sh HISTORY
+The
+.Fn posix_memalign
+function first appeared in
+.Ox 4.8 .
+.Sh BUGS
+Only alignments up to the page size can be specified.
diff --git a/lib/libc/string/Makefile.inc b/lib/libc/string/Makefile.inc
index 8aa072a2893..3264b799f17 100644
--- a/lib/libc/string/Makefile.inc
+++ b/lib/libc/string/Makefile.inc
@@ -1,11 +1,11 @@
-#	$OpenBSD: Makefile.inc,v 1.21 2010/02/03 20:49:00 miod Exp $
+#	$OpenBSD: Makefile.inc,v 1.22 2010/05/18 22:24:55 tedu Exp $
 
 # string sources
 .PATH: ${LIBCSRCDIR}/arch/${MACHINE_CPU}/string ${LIBCSRCDIR}/string
 
 SRCS+=	bm.c memccpy.c memrchr.c strcasecmp.c strcasestr.c strcoll.c strdup.c \
-	strerror.c strerror_r.c strlcat.c strmode.c strsignal.c strtok.c \
-	strxfrm.c \
+	strerror.c strerror_r.c strlcat.c strmode.c strndup.c strnlen.c \
+	strsignal.c strtok.c strxfrm.c \
 	wcscat.c wcschr.c wcscmp.c wcscpy.c wcscspn.c wcslcat.c wcslcpy.c \
 	wcslen.c wcsncat.c wcsncmp.c wcsncpy.c wcspbrk.c wcsrchr.c wcsspn.c \
 	wcsstr.c wcstok.c wcswcs.c wcswidth.c wmemchr.c wmemcmp.c wmemcpy.c \
@@ -153,7 +153,9 @@ MLINKS+=strcasecmp.3 strncasecmp.3
 MLINKS+=strcat.3 strncat.3
 MLINKS+=strcmp.3 strncmp.3
 MLINKS+=strcpy.3 strncpy.3
+MLINKS+=strdup.3 strndup.3
 MLINKS+=strlcpy.3 strlcat.3
+MLINKS+=strlen.3 strnlen.3
 MLINKS+=strstr.3 strcasestr.3
 MLINKS+=strtok.3 strtok_r.3
 MLINKS+=strerror.3 strerror_r.3
diff --git a/lib/libc/string/strdup.3 b/lib/libc/string/strdup.3
index 60a74627771..05dcb794f04 100644
--- a/lib/libc/string/strdup.3
+++ b/lib/libc/string/strdup.3
@@ -1,4 +1,4 @@
-.\" $OpenBSD: strdup.3,v 1.15 2010/03/24 14:47:46 kettenis Exp $
+.\" $OpenBSD: strdup.3,v 1.16 2010/05/18 22:24:55 tedu Exp $
 .\"
 .\" Copyright (c) 1990, 1991, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -29,16 +29,19 @@
 .\"
 .\"     @(#)strdup.3	8.1 (Berkeley) 6/9/93
 .\"
-.Dd $Mdocdate: March 24 2010 $
+.Dd $Mdocdate: May 18 2010 $
 .Dt STRDUP 3
 .Os
 .Sh NAME
-.Nm strdup
+.Nm strdup ,
+.Nm strndup
 .Nd save a copy of a string
 .Sh SYNOPSIS
 .Fd #include <string.h>
 .Ft char *
 .Fn strdup "const char *s"
+.Ft char *
+.Fn strndup "const char *s" "size_t maxlen"
 .Sh DESCRIPTION
 The
 .Fn strdup
@@ -48,6 +51,16 @@ does the copy, and returns a pointer to it.
 The pointer may subsequently be used as an argument to the function
 .Xr free 3 .
 .Pp
+The
+.Fn strndup
+function behaves similarly to
+.Nm strdup
+but only copies up to
+.Fa maxlen
+characters from
+.Fa s .
+The resulting string is always NUL-terminated.
+.Pp
 If insufficient memory is available,
 .Dv NULL
 is returned.
@@ -83,3 +96,15 @@ The
 .Fn strdup
 function first appeared in
 .Bx 4.4 .
+.Pp
+The
+.Fn strndup
+function first appeared in
+.Ox 4.8 .
+.Sh STANDARDS
+The
+.Fn strdup
+and
+.Fn strndup
+functions conform to
+.St -p1003.1-2008 .
diff --git a/lib/libc/string/strlen.3 b/lib/libc/string/strlen.3
index f8a4efe9d24..3b5f9a10c12 100644
--- a/lib/libc/string/strlen.3
+++ b/lib/libc/string/strlen.3
@@ -29,29 +29,55 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"	$OpenBSD: strlen.3,v 1.6 2007/05/31 19:19:32 jmc Exp $
+.\"	$OpenBSD: strlen.3,v 1.7 2010/05/18 22:24:55 tedu Exp $
 .\"
-.Dd $Mdocdate: May 31 2007 $
+.Dd $Mdocdate: May 18 2010 $
 .Dt STRLEN 3
 .Os
 .Sh NAME
-.Nm strlen
+.Nm strlen ,
+.Nm strnlen
 .Nd find length of a string
 .Sh SYNOPSIS
 .Fd #include <string.h>
 .Ft size_t
 .Fn strlen "const char *s"
+.Ft size_t
+.Fn strnlen "const char *s" "size_t maxlen"
 .Sh DESCRIPTION
 The
 .Fn strlen
 function computes the length of the string
 .Fa s .
+.Pp
+The
+.Fn strnlen
+function computes the length of the string
+.Fa s ,
+up to
+.Fa maxlen
+characters.
+The
+.Fn strnlen
+function will never attempt to address more than
+.Fa maxlen
+characters, making it suitable for use with character arrays that are
+not guaranteed to be NUL-terminated.
+.Pp
 .Sh RETURN VALUES
 The
 .Fn strlen
 function returns the number of characters that precede the terminating
 .Tn NUL
 character.
+.Pp
+The
+.Fn strnlen
+function returns the number of characters that precede the terminating
+.Tn NUL
+or
+.Fa maxlen ,
+whichever is smaller.
 .Sh SEE ALSO
 .Xr string 3
 .Sh STANDARDS
@@ -59,3 +85,10 @@ The
 .Fn strlen
 function conforms to
 .St -ansiC .
+.Pp
+The
+.Fn strlen
+and
+.Fn strnlen
+functions conform to
+.St -p1003.1-2008 .
diff --git a/lib/libc/string/strndup.c b/lib/libc/string/strndup.c
new file mode 100644
index 00000000000..27701ac555a
--- /dev/null
+++ b/lib/libc/string/strndup.c
@@ -0,0 +1,39 @@
+/*	$OpenBSD: strndup.c,v 1.1 2010/05/18 22:24:55 tedu Exp $	*/
+
+/*
+ * Copyright (c) 2010 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * 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/types.h>
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+char *
+strndup(const char *str, size_t maxlen)
+{
+	char *copy;
+	size_t len;
+
+	len = strnlen(str, maxlen);
+	copy = malloc(len + 1);
+	if (copy != NULL) {
+		(void)memcpy(copy, str, len);
+		copy[len] = '\0';
+	}
+
+	return copy;
+}
diff --git a/lib/libc/string/strnlen.c b/lib/libc/string/strnlen.c
new file mode 100644
index 00000000000..5c999947444
--- /dev/null
+++ b/lib/libc/string/strnlen.c
@@ -0,0 +1,34 @@
+/*	$OpenBSD: strnlen.c,v 1.1 2010/05/18 22:24:55 tedu Exp $	*/
+
+/*
+ * Copyright (c) 2010 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * 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/types.h>
+
+#include <string.h>
+
+size_t
+strnlen(const char *str, size_t maxlen)
+{
+	const char *cp, *ep;
+	size_t len;
+
+	ep = str + maxlen;
+	for (cp = str; cp < ep && *cp != '\0'; cp++)
+		;
+
+	return (size_t)(cp - str);
+}
diff --git a/lib/libc/sys/Makefile.inc b/lib/libc/sys/Makefile.inc
index 6e440ac40ce..4d31ad1411c 100644
--- a/lib/libc/sys/Makefile.inc
+++ b/lib/libc/sys/Makefile.inc
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile.inc,v 1.89 2010/02/03 20:49:00 miod Exp $
+#	$OpenBSD: Makefile.inc,v 1.90 2010/05/18 22:24:55 tedu Exp $
 #	$NetBSD: Makefile.inc,v 1.35 1995/10/16 23:49:07 jtc Exp $
 #	@(#)Makefile.inc	8.1 (Berkeley) 6/17/93
 
@@ -23,6 +23,9 @@ DPSRCS+= Lint_Ovfork.c Lint_brk.c Lint_exect.c Lint_fork.c \
 	Lint_setjmp.c Lint_longjmp.c \
 	Lint_sigsetjmp.c Lint_siglongjmp.c
 
+# glue to offer userland wrappers for some syscalls
+SRCS+=	posix_madvise.c
+
 # glue to provide compatibility between GCC 1.X and 2.X and for compat
 # with old syscall interfaces.
 SRCS+=	ftruncate.c lseek.c mquery.c mmap.c ptrace.c semctl.c truncate.c \
@@ -264,6 +267,7 @@ MLINKS+=gettimeofday.2 settimeofday.2
 MLINKS+=getuid.2 geteuid.2
 MLINKS+=kqueue.2 kevent.2 kqueue.2 EV_SET.2
 MLINKS+=intro.2 errno.2
+MLINKS+=madvise.2 posix_madvise.2
 MLINKS+=mlock.2 munlock.2
 MLINKS+=mlockall.2 munlockall.2
 MLINKS+=mount.2 unmount.2
diff --git a/lib/libc/sys/madvise.2 b/lib/libc/sys/madvise.2
index 7ac374636d0..0bd769da626 100644
--- a/lib/libc/sys/madvise.2
+++ b/lib/libc/sys/madvise.2
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: madvise.2,v 1.14 2007/05/31 19:19:32 jmc Exp $
+.\"	$OpenBSD: madvise.2,v 1.15 2010/05/18 22:24:55 tedu Exp $
 .\"	$NetBSD: madvise.2,v 1.7 1995/12/27 21:17:02 jtc Exp $
 .\"
 .\" Copyright (c) 1991, 1993
@@ -30,23 +30,29 @@
 .\"
 .\"	@(#)madvise.2	8.1 (Berkeley) 6/9/93
 .\"
-.Dd $Mdocdate: May 31 2007 $
+.Dd $Mdocdate: May 18 2010 $
 .Dt MADVISE 2
 .Os
 .Sh NAME
-.Nm madvise
+.Nm madvise ,
+.Nm posix_madvise
 .Nd give advice about use of memory
 .Sh SYNOPSIS
-.Fd #include <sys/types.h>
 .Fd #include <sys/mman.h>
 .Ft int
 .Fn madvise "void *addr" "size_t len" "int behav"
+.Ft int
+.Fn posix_madvise "void *addr" "size_t len" "int behav"
 .Sh DESCRIPTION
 The
 .Fn madvise
 system call
 allows a process that has knowledge of its memory behavior
 to describe it to the system.
+The
+.Fn posix_madvise
+interface is identical and is provided for standards conformance.
+.Pp
 The possible behaviors are:
 .Bl -tag -width MADV_SEQUENTIAL
 .It Dv MADV_NORMAL
@@ -64,6 +70,15 @@ Ensure that resources are reserved.
 .It Dv MADV_FREE
 The pages don't contain any useful data and can be recycled.
 .El
+.Pp
+Portable programs that call the
+.Fn posix_madvise
+interface should use the aliases
+.Dv POSIX_MADV_NORMAL , POSIX_MADV_RANDOM ,
+.Dv POSIX_MADV_SEQUENTIAL , POSIX_MADV_WILLNEED ,
+and
+.Dv POSIX_MADV_DONTNEED
+rather than the flags described above.
 .Sh RETURN VALUES
 Upon successful completion,
 a value of 0 is returned.
@@ -75,9 +90,21 @@ is set to indicate the error.
 .Xr minherit 2 ,
 .Xr mprotect 2 ,
 .Xr msync 2 ,
-.Xr munmap 2
+.Xr munmap 2 ,
+.Xr posix_madvise 2
+.Sh STANDARDS
+The
+.Fn posix_madvise
+system call is expected to conform to the
+.St -p1003.1-2001
+standard.
 .Sh HISTORY
 The
 .Nm madvise
 function first appeared in
 .Bx 4.4 .
+The
+.Nm posix_madvise
+function first appeared in
+.Ox 4.8 .
+
diff --git a/lib/libc/sys/posix_madvise.c b/lib/libc/sys/posix_madvise.c
new file mode 100644
index 00000000000..4952c5cc77a
--- /dev/null
+++ b/lib/libc/sys/posix_madvise.c
@@ -0,0 +1,11 @@
+/*	$OpenBSD: posix_madvise.c,v 1.1 2010/05/18 22:24:55 tedu Exp $ */
+/*
+ * Ted Unangst wrote this file and placed it into the public domain.
+ */
+#include <sys/mman.h>
+
+int
+posix_madvise(void *addr, size_t len, int behav)
+{
+	return (_thread_sys_madvise(addr, len, behav));
+}