Fix known issues which blow up the process after dlopen("libthr.so")

(or loading a dso linked to libthr.so into process which was not
linked against threading library).

- Remove libthr interposers of the libc functions, including
  __error(). Instead, functions calls are indirected through the
  interposing table, similar to how pthread stubs in libc are already
  done.  Libc by default points either to syscall trampolines or to
  existing libc implementations.  On libthr load, libthr rewrites the
  pointers to the cancellable implementations already in libthr.  The
  interposition table is separate from pthreads stubs indirection
  table to not pull pthreads stubs into static binaries.

- Postpone the malloc(3) internal mutexes initialization until libthr
  is loaded.  This avoids recursion between calloc(3) and static
  pthread_mutex_t initialization.

- Reinstall signal handlers with wrapper on libthr load.  The
  _rtld_is_dlopened(3) is used to avoid useless calls to sigaction(2)
  when libthr is statically referenced from the main binary.

In the process, fix openat(2), swapcontext(2) and setcontext(2)
interposing.  The libc symbols were exported at different versions
than libthr interposers.  Export both libc and libthr versions from
libc now, with default set to the higher version from libthr.

Remove unused and disconnected swapcontext(3) userspace implementation
from libc/gen.

No objections from:	deischen
Tested by:	pho, antoine (exp-run) (previous versions)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week

36 files changed, 1707 insertions, 20 deletions

diff --git a/lib/libc/sys/Makefile.inc b/lib/libc/sys/Makefile.inc
index c14b35111e78..0a3c13f8e3b1 100644
--- a/lib/libc/sys/Makefile.inc
+++ b/lib/libc/sys/Makefile.inc
@@ -20,17 +20,61 @@ NOASM+=  clock_gettime.o gettimeofday.o
 PSEUDO+= _clock_gettime.o _gettimeofday.o
 
 # Sources common to both syscall interfaces:
-SRCS+=	stack_protector.c stack_protector_compat.c __error.c
+SRCS+=	\
+	stack_protector.c \
+	stack_protector_compat.c \
+	__error.c \
+	interposing_table.c
+
 .if ${MK_SYSCALL_COMPAT} != "no"
-SYSCALL_COMPAT_SRCS=	fcntl.c ftruncate.c lseek.c mmap.c pread.c \
-	pwrite.c truncate.c
+SYSCALL_COMPAT_SRCS= \
+	ftruncate.c \
+	lseek.c \
+	mmap.c \
+	pread.c \
+	pwrite.c \
+	truncate.c
 SRCS+=	${SYSCALL_COMPAT_SRCS}
 NOASM+=	${SYSCALL_COMPAT_SRCS:S/.c/.o/}
-PSEUDO+= _fcntl.o
 .endif
-SRCS+= sigwait.c
-NOASM+= sigwait.o
-PSEUDO+= _sigwait.o
+
+INTERPOSED = \
+	accept \
+	accept4 \
+	aio_suspend \
+	close \
+	connect \
+	fcntl \
+	fsync \
+	fork \
+	msync \
+	nanosleep \
+	open \
+	openat \
+	poll \
+	pselect \
+	read \
+	readv \
+	recvfrom \
+	recvmsg \
+	select \
+	sendmsg \
+	sendto \
+	setcontext \
+	sigaction \
+	sigprocmask \
+	sigsuspend \
+	sigtimedwait \
+	sigwait \
+	sigwaitinfo \
+	swapcontext \
+	wait4 \
+	write \
+	writev
+
+SRCS+=	${INTERPOSED:S/$/.c/}
+NOASM+=	${INTERPOSED:S/$/.o/}
+PSEUDO+=	${INTERPOSED:C/^.*$/_&.o/}
 
 # Add machine dependent asm sources:
 SRCS+=${MDASM}
diff --git a/lib/libc/sys/Symbol.map b/lib/libc/sys/Symbol.map
index 448bcce26753..7d823614816a 100644
--- a/lib/libc/sys/Symbol.map
+++ b/lib/libc/sys/Symbol.map
@@ -245,7 +245,6 @@ FBSD_1.0 {
 	setaudit;
 	setaudit_addr;
 	setauid;
-	setcontext;
 	setegid;
 	seteuid;
 	setgid;
@@ -286,7 +285,6 @@ FBSD_1.0 {
 	__stack_chk_guard;
 	stat;
 	statfs;
-	swapcontext;
 	swapoff;
 	swapon;
 	symlink;
@@ -351,7 +349,6 @@ FBSD_1.1 {
 	mkfifoat;
 	mknodat;
 	msgctl;
-	openat;
 	readlinkat;
 	renameat;
 	setfib;
@@ -1049,6 +1046,9 @@ FBSDprivate_1.0 {
 	_writev;
 	__sys_writev;
 	__error_unthreaded;
+	__error_selector;
 	nlm_syscall;
 	gssd_syscall;
+	__libc_interposing_slot;
+	__libc_sigwait;
 };
diff --git a/lib/libc/sys/__error.c b/lib/libc/sys/__error.c
index c3f59f8bf828..329d124a16db 100644
--- a/lib/libc/sys/__error.c
+++ b/lib/libc/sys/__error.c
@@ -32,14 +32,17 @@ __FBSDID("$FreeBSD$");
 
 extern int errno;
 
-/*
- * Declare a weak reference in case the application is not linked
- * with libpthread.
- */
-__weak_reference(__error_unthreaded, __error);
-
 int *
 __error_unthreaded(void)
 {
 	return(&errno);
 }
+
+int *(*__error_selector)(void) = __error_unthreaded;
+
+int *
+__error(void)
+{
+
+	return (__error_selector());
+}
diff --git a/lib/libc/sys/accept.c b/lib/libc/sys/accept.c
new file mode 100644
index 000000000000..38e32f2c836d
--- /dev/null
+++ b/lib/libc/sys/accept.c
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <sys/socket.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_accept, __accept);
+
+#pragma weak accept
+int
+accept(int s, struct sockaddr *addr, socklen_t *addrlen)
+{
+
+	return (((int (*)(int, struct sockaddr *, socklen_t *))
+	    __libc_interposing[INTERPOS_accept])(s, addr, addrlen));
+}
diff --git a/lib/libc/sys/accept4.c b/lib/libc/sys/accept4.c
new file mode 100644
index 000000000000..2907b047efdc
--- /dev/null
+++ b/lib/libc/sys/accept4.c
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <sys/socket.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_accept4, __accept4);
+
+#pragma weak accept4
+int
+accept4(int s, struct sockaddr *addr, socklen_t *addrlen, int flags)
+{
+
+	return (((int (*)(int, struct sockaddr *, socklen_t *, int))
+	    __libc_interposing[INTERPOS_accept4])(s, addr, addrlen, flags));
+}
diff --git a/lib/libc/sys/aio_suspend.c b/lib/libc/sys/aio_suspend.c
new file mode 100644
index 000000000000..020edf8a74fa
--- /dev/null
+++ b/lib/libc/sys/aio_suspend.c
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/aio.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_aio_suspend, __aio_suspend);
+
+#pragma weak aio_suspend
+int
+aio_suspend(const struct aiocb * const iocbs[], int niocb,
+    const struct timespec *timeout)
+{
+
+	return (((int (*)(const struct aiocb * const[], int,
+	    const struct timespec *))
+	    __libc_interposing[INTERPOS_aio_suspend])(iocbs, niocb, timeout));
+}
diff --git a/lib/libc/sys/close.c b/lib/libc/sys/close.c
new file mode 100644
index 000000000000..02e74c633001
--- /dev/null
+++ b/lib/libc/sys/close.c
@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/fcntl.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_close, __close);
+
+#pragma weak close
+int
+close(int fd)
+{
+
+	return (((int (*)(int))__libc_interposing[INTERPOS_close])(fd));
+}
diff --git a/lib/libc/sys/connect.c b/lib/libc/sys/connect.c
new file mode 100644
index 000000000000..7969142ad072
--- /dev/null
+++ b/lib/libc/sys/connect.c
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <sys/socket.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_connect, __connect);
+
+#pragma weak connect
+int
+connect(int s, const struct sockaddr *addr, socklen_t addrlen)
+{
+
+	return (((int (*)(int, const struct sockaddr *, socklen_t))
+	    __libc_interposing[INTERPOS_connect])(s, addr, addrlen));
+}
diff --git a/lib/libc/sys/fcntl.c b/lib/libc/sys/fcntl.c
index 480cc40cb69e..4cb887b6afd2 100644
--- a/lib/libc/sys/fcntl.c
+++ b/lib/libc/sys/fcntl.c
@@ -34,7 +34,23 @@ __FBSDID("$FreeBSD$");
 #include <sys/syscall.h>
 #include "libc_private.h"
 
-__weak_reference(__fcntl_compat, fcntl);
+#pragma weak fcntl
+int
+fcntl(int fd, int cmd, ...)
+{
+	va_list args;
+	long arg;
+
+	va_start(args, cmd);
+	arg = va_arg(args, long);
+	va_end(args);
+
+	return (((int (*)(int, int, ...))
+	    __libc_interposing[INTERPOS_fcntl])(fd, cmd, arg));
+}
+
+#ifdef SYSCALL_COMPAT
+__weak_reference(__fcntl_compat, __fcntl);
 
 int
 __fcntl_compat(int fd, int cmd, ...)
@@ -87,3 +103,7 @@ __fcntl_compat(int fd, int cmd, ...)
 		return (__sys_fcntl(fd, cmd, arg));
 	}
 }
+#else
+__weak_reference(__sys_fcntl, __fcntl_compat);
+__weak_reference(__sys_fcntl, __fcntl);
+#endif
diff --git a/lib/libc/sys/fork.c b/lib/libc/sys/fork.c
new file mode 100644
index 000000000000..695540a7264f
--- /dev/null
+++ b/lib/libc/sys/fork.c
@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <unistd.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_fork, __fork);
+
+#pragma weak fork
+pid_t
+fork(void)
+{
+
+	return (((pid_t (*)(void))__libc_interposing[INTERPOS_fork])());
+}
diff --git a/lib/libc/sys/fsync.c b/lib/libc/sys/fsync.c
new file mode 100644
index 000000000000..3fff428f1ab7
--- /dev/null
+++ b/lib/libc/sys/fsync.c
@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/fcntl.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_fsync, __fsync);
+
+int
+fsync(int fd)
+{
+
+	return (((int (*)(int))__libc_interposing[INTERPOS_fsync])(fd));
+}
diff --git a/lib/libc/sys/interposing_table.c b/lib/libc/sys/interposing_table.c
new file mode 100644
index 000000000000..9987bf057a6c
--- /dev/null
+++ b/lib/libc/sys/interposing_table.c
@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include "libc_private.h"
+
+#define	SLOT(a, b) \
+	[INTERPOS_##a] = (interpos_func_t)b
+interpos_func_t __libc_interposing[INTERPOS_MAX] = {
+	SLOT(accept, __sys_accept),
+	SLOT(accept4, __sys_accept4),
+	SLOT(aio_suspend, __sys_aio_suspend),
+	SLOT(close, __sys_close),
+	SLOT(connect, __sys_connect),
+	SLOT(creat, __libc_creat),
+	SLOT(fcntl, __fcntl_compat),
+	SLOT(fsync, __sys_fsync),
+	SLOT(fork, __sys_fork),
+	SLOT(msync, __sys_msync),
+	SLOT(nanosleep, __sys_nanosleep),
+	SLOT(open, __sys_open),
+	SLOT(openat, __sys_openat),
+	SLOT(poll, __sys_poll),
+	SLOT(pselect, __sys_pselect),
+	SLOT(raise, __libc_raise),
+	SLOT(read, __sys_read),
+	SLOT(readv, __sys_readv),
+	SLOT(recvfrom, __sys_recvfrom),
+	SLOT(recvmsg, __sys_recvmsg),
+	SLOT(select, __sys_select),
+	SLOT(sendmsg, __sys_sendmsg),
+	SLOT(sendto, __sys_sendto),
+	SLOT(setcontext, __sys_setcontext),
+	SLOT(sigaction, __sys_sigaction),
+	SLOT(sigprocmask, __sys_sigprocmask),
+	SLOT(sigsuspend, __sys_sigsuspend),
+	SLOT(sigwait, __libc_sigwait),
+	SLOT(sigtimedwait, __sys_sigtimedwait),
+	SLOT(sigwaitinfo, __sys_sigwaitinfo),
+	SLOT(swapcontext, __sys_swapcontext),
+	SLOT(system, __libc_system),
+	SLOT(sleep, __libc_sleep),
+	SLOT(tcdrain, __libc_tcdrain),
+	SLOT(usleep, __libc_usleep),
+	SLOT(pause, __libc_pause),
+	SLOT(wait, __libc_wait),
+	SLOT(wait3, __libc_wait3),
+	SLOT(wait4, __sys_wait4),
+	SLOT(waitpid, __libc_waitpid),
+	SLOT(write, __sys_write),
+	SLOT(writev, __sys_writev),
+	SLOT(_pthread_mutex_init_calloc_cb, _pthread_mutex_init_calloc_cb_stub),
+};
+#undef SLOT
+
+interpos_func_t *
+__libc_interposing_slot(int interposno)
+{
+
+	return (&__libc_interposing[interposno]);
+}
diff --git a/lib/libc/sys/msync.c b/lib/libc/sys/msync.c
new file mode 100644
index 000000000000..3c6879f04c64
--- /dev/null
+++ b/lib/libc/sys/msync.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/fcntl.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_msync, __msync);
+
+#pragma weak msync
+int
+msync(void *addr, size_t len, int flags)
+{
+
+	return (((int (*)(void *, size_t, int))
+	    __libc_interposing[INTERPOS_msync])(addr, len, flags));
+}
diff --git a/lib/libc/sys/nanosleep.c b/lib/libc/sys/nanosleep.c
new file mode 100644
index 000000000000..412b05e778b0
--- /dev/null
+++ b/lib/libc/sys/nanosleep.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <time.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_nanosleep, __nanosleep);
+
+#pragma weak nanosleep
+int
+nanosleep(const struct timespec *rqtp, struct timespec *rmtp)
+{
+
+	return (((int (*)(const struct timespec *, struct timespec *))
+	    __libc_interposing[INTERPOS_nanosleep])(rqtp, rmtp));
+}
diff --git a/lib/libc/sys/open.c b/lib/libc/sys/open.c
new file mode 100644
index 000000000000..57c0324c545c
--- /dev/null
+++ b/lib/libc/sys/open.c
@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/fcntl.h>
+#include <stdarg.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_open, __open);
+
+#pragma weak open
+int
+open(const char *path, int flags, ...)
+{
+	va_list ap;
+	int mode;
+
+	if ((flags & O_CREAT) != 0) {
+		va_start(ap, flags);
+		mode = va_arg(ap, int);
+		va_end(ap);
+	} else {
+		mode = 0;
+	}
+	return (((int (*)(const char *, int, ...))
+	    __libc_interposing[INTERPOS_open])(path, flags, mode));
+}
diff --git a/lib/libc/sys/openat.c b/lib/libc/sys/openat.c
new file mode 100644
index 000000000000..1bd12ea2a8d8
--- /dev/null
+++ b/lib/libc/sys/openat.c
@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/fcntl.h>
+#include <stdarg.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_openat, __openat);
+__sym_compat(openat, __impl_openat, FBSD_1.1);
+__weak_reference(openat, __impl_openat);
+__sym_default(openat, openat, FBSD_1.2);
+
+#pragma weak openat
+int
+openat(int fd, const char *path, int flags, ...)
+{
+	va_list ap;
+	int mode;
+
+	if ((flags & O_CREAT) != 0) {
+		va_start(ap, flags);
+		mode = va_arg(ap, int);
+		va_end(ap);
+	} else {
+		mode = 0;
+	}
+	return (((int (*)(int, const char *, int, ...))
+	    __libc_interposing[INTERPOS_openat])(fd, path, flags, mode));
+}
diff --git a/lib/libc/sys/poll.c b/lib/libc/sys/poll.c
new file mode 100644
index 000000000000..43c17d2f65ce
--- /dev/null
+++ b/lib/libc/sys/poll.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/poll.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_poll, __poll);
+
+#pragma weak poll
+int
+poll(struct pollfd pfd[], nfds_t nfds, int timeout)
+{
+
+	return (((int (*)(struct pollfd *, nfds_t, int))
+	    __libc_interposing[INTERPOS_poll])(pfd, nfds, timeout));
+}
diff --git a/lib/libc/sys/pselect.c b/lib/libc/sys/pselect.c
new file mode 100644
index 000000000000..a623a7d5cc74
--- /dev/null
+++ b/lib/libc/sys/pselect.c
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/select.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_pselect, __pselect);
+
+#pragma weak pselect
+int
+pselect(int n, fd_set *rs, fd_set *ws, fd_set *es, const struct timespec *t,
+    const sigset_t *s)
+{
+
+	return (((int (*)(int, fd_set *, fd_set *, fd_set *,
+	    const struct timespec *, const sigset_t *))
+	    __libc_interposing[INTERPOS_pselect])(n, rs, ws, es, t, s));
+}
diff --git a/lib/libc/sys/read.c b/lib/libc/sys/read.c
new file mode 100644
index 000000000000..ab30189026e3
--- /dev/null
+++ b/lib/libc/sys/read.c
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_read, __read);
+
+#pragma weak read
+ssize_t
+read(int fd, void *buf, size_t nbytes)
+{
+
+	return (((ssize_t (*)(int, void *, size_t))
+	    __libc_interposing[INTERPOS_read])(fd, buf, nbytes));
+}
diff --git a/lib/libc/sys/readv.c b/lib/libc/sys/readv.c
new file mode 100644
index 000000000000..8c82040367cc
--- /dev/null
+++ b/lib/libc/sys/readv.c
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_readv, __readv);
+
+#pragma weak readv
+ssize_t
+readv(int fd, const struct iovec *iov, int iovcnt)
+{
+
+	return (((ssize_t (*)(int, const struct iovec *, int))
+	    __libc_interposing[INTERPOS_readv])(fd, iov, iovcnt));
+}
diff --git a/lib/libc/sys/recvfrom.c b/lib/libc/sys/recvfrom.c
new file mode 100644
index 000000000000..aa6ef3fb7be2
--- /dev/null
+++ b/lib/libc/sys/recvfrom.c
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <sys/socket.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_recvfrom, __recvfrom);
+
+#pragma weak recvfrom
+ssize_t
+recvfrom(int s, void *buf, size_t len, int flags,
+    struct sockaddr * __restrict from, socklen_t * __restrict fromlen)
+{
+
+	return (((ssize_t (*)(int, void *, size_t, int,
+	    struct sockaddr *, socklen_t *))
+	    __libc_interposing[INTERPOS_recvfrom])(s, buf, len, flags,
+	   from, fromlen));
+}
diff --git a/lib/libc/sys/recvmsg.c b/lib/libc/sys/recvmsg.c
new file mode 100644
index 000000000000..282ede9995ff
--- /dev/null
+++ b/lib/libc/sys/recvmsg.c
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <sys/socket.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_recvmsg, __recvmsg);
+
+#pragma weak recvmsg
+ssize_t
+recvmsg(int s, struct msghdr *msg, int flags)
+{
+
+	return (((int (*)(int, struct msghdr *, int))
+	    __libc_interposing[INTERPOS_recvmsg])(s, msg, flags));
+}
diff --git a/lib/libc/sys/select.c b/lib/libc/sys/select.c
new file mode 100644
index 000000000000..3990496ec412
--- /dev/null
+++ b/lib/libc/sys/select.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/select.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_select, __select);
+
+#pragma weak select
+int
+select(int n, fd_set *rs, fd_set *ws, fd_set *es, struct timeval *t)
+{
+
+	return (((int (*)(int, fd_set *, fd_set *, fd_set *, struct timeval *))
+	    __libc_interposing[INTERPOS_select])(n, rs, ws, es, t));
+}
diff --git a/lib/libc/sys/sendmsg.c b/lib/libc/sys/sendmsg.c
new file mode 100644
index 000000000000..794464339043
--- /dev/null
+++ b/lib/libc/sys/sendmsg.c
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <sys/socket.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_sendmsg, __sendmsg);
+
+#pragma weak sendmsg
+ssize_t
+sendmsg(int s, const struct msghdr *msg, int flags)
+{
+
+	return (((int (*)(int, const struct msghdr *, int))
+	    __libc_interposing[INTERPOS_sendmsg])(s, msg, flags));
+}
diff --git a/lib/libc/sys/sendto.c b/lib/libc/sys/sendto.c
new file mode 100644
index 000000000000..ecf98ee05b19
--- /dev/null
+++ b/lib/libc/sys/sendto.c
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <sys/socket.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_sendto, __sendto);
+
+#pragma weak sendto
+ssize_t
+sendto(int s, const void *msg, size_t len, int flags,
+    const struct sockaddr *to, socklen_t tolen)
+{
+
+	return (((ssize_t (*)(int, const void *, size_t, int,
+	    const struct sockaddr *, socklen_t))
+	    __libc_interposing[INTERPOS_sendto])(s, msg, len, flags,
+	    to, tolen));
+}
diff --git a/lib/libc/sys/setcontext.c b/lib/libc/sys/setcontext.c
new file mode 100644
index 000000000000..31b888f2bcff
--- /dev/null
+++ b/lib/libc/sys/setcontext.c
@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <ucontext.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_setcontext, __setcontext);
+__sym_compat(setcontext, __impl_setcontext, FBSD_1.0);
+__weak_reference(setcontext, __impl_setcontext);
+__sym_default(setcontext, setcontext, FBSD_1.2);
+
+#pragma weak setcontext
+int
+setcontext(const ucontext_t *uc)
+{
+
+	return (((int (*)(const ucontext_t *))
+	    __libc_interposing[INTERPOS_setcontext])(uc));
+}
diff --git a/lib/libc/sys/sigaction.c b/lib/libc/sys/sigaction.c
new file mode 100644
index 000000000000..7645538cf3b9
--- /dev/null
+++ b/lib/libc/sys/sigaction.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <signal.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_sigaction, __sigaction);
+
+#pragma weak sigaction
+int
+sigaction(int sig, const struct sigaction *act, struct sigaction *oact)
+{
+
+	return (((int (*)(int, const struct sigaction *, struct sigaction *))
+	    __libc_interposing[INTERPOS_sigaction])(sig, act, oact));
+}
diff --git a/lib/libc/sys/sigprocmask.c b/lib/libc/sys/sigprocmask.c
new file mode 100644
index 000000000000..40dba95563be
--- /dev/null
+++ b/lib/libc/sys/sigprocmask.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <signal.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_sigprocmask, __sigprocmask);
+
+#pragma weak sigprocmask
+int
+sigprocmask(int how, const sigset_t *set, sigset_t *oset)
+{
+
+	return (((int (*)(int, const sigset_t *, sigset_t *))
+	    __libc_interposing[INTERPOS_sigprocmask])(how, set, oset));
+}
diff --git a/lib/libc/sys/sigsuspend.c b/lib/libc/sys/sigsuspend.c
new file mode 100644
index 000000000000..6e47368c49c3
--- /dev/null
+++ b/lib/libc/sys/sigsuspend.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <signal.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_sigsuspend, __sigsuspend);
+
+#pragma weak sigsuspend
+int
+sigsuspend(const sigset_t *set)
+{
+
+	return (((int (*)(const sigset_t *))
+	    __libc_interposing[INTERPOS_sigsuspend])(set));
+}
diff --git a/lib/libc/sys/sigtimedwait.c b/lib/libc/sys/sigtimedwait.c
new file mode 100644
index 000000000000..4e067192ca4b
--- /dev/null
+++ b/lib/libc/sys/sigtimedwait.c
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <signal.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_sigtimedwait, __sigtimedwait);
+
+#pragma weak sigtimedwait
+int
+sigtimedwait(const sigset_t * __restrict set, siginfo_t * __restrict info,
+    const struct timespec * __restrict t)
+{
+
+	return (((int (*)(const sigset_t *, siginfo_t *,
+	    const struct timespec *))
+	    __libc_interposing[INTERPOS_sigtimedwait])(set, info, t));
+}
diff --git a/lib/libc/sys/sigwait.c b/lib/libc/sys/sigwait.c
index 2fdffdd06db8..b21cabdeac55 100644
--- a/lib/libc/sys/sigwait.c
+++ b/lib/libc/sys/sigwait.c
@@ -28,13 +28,21 @@ __FBSDID("$FreeBSD$");
 
 #include <errno.h>
 #include <signal.h>
+#include "libc_private.h"
 
-int __sys_sigwait(const sigset_t * restrict, int * restrict);
+__weak_reference(__libc_sigwait, __sigwait);
 
-__weak_reference(__sigwait, sigwait);
+#pragma weak sigwait
+int
+sigwait(const sigset_t *set, int *sig)
+{
+
+	return (((int (*)(const sigset_t *, int *))
+	    __libc_interposing[INTERPOS_sigwait])(set, sig));
+}
 
 int
-__sigwait(const sigset_t * restrict set, int * restrict sig)
+__libc_sigwait(const sigset_t *set, int *sig)
 {
 	int ret;
 
diff --git a/lib/libc/sys/sigwaitinfo.c b/lib/libc/sys/sigwaitinfo.c
new file mode 100644
index 000000000000..b9cdc79bc224
--- /dev/null
+++ b/lib/libc/sys/sigwaitinfo.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <signal.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_sigwaitinfo, __sigwaitinfo);
+
+#pragma weak sigwaitinfo
+int
+sigwaitinfo(const sigset_t * __restrict set, siginfo_t * __restrict info)
+{
+
+	return (((int (*)(const sigset_t *, siginfo_t *))
+	    __libc_interposing[INTERPOS_sigwaitinfo])(set, info));
+}
diff --git a/lib/libc/sys/swapcontext.c b/lib/libc/sys/swapcontext.c
new file mode 100644
index 000000000000..0a8125eeabb5
--- /dev/null
+++ b/lib/libc/sys/swapcontext.c
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2001 Daniel M. Eischen <deischen@freebsd.org>
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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. Neither the name of the author 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 AUTHOR 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 AUTHOR 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/signal.h>
+#include <sys/ucontext.h>
+#include <errno.h>
+#include <stddef.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_swapcontext, __swapcontext);
+__sym_compat(swapcontext, __impl_swapcontext, FBSD_1.0);
+__weak_reference(swapcontext, __impl_swapcontext);
+__sym_default(swapcontext, swapcontext, FBSD_1.2);
+
+#pragma weak swapcontext
+int
+swapcontext(ucontext_t *oucp, const ucontext_t *ucp)
+{
+
+	return (((int (*)(ucontext_t *, const ucontext_t *))
+	    __libc_interposing[INTERPOS_swapcontext])(oucp, ucp));
+}
diff --git a/lib/libc/sys/wait4.c b/lib/libc/sys/wait4.c
new file mode 100644
index 000000000000..a5dbd0fcb1aa
--- /dev/null
+++ b/lib/libc/sys/wait4.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/wait.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_wait4, __wait4);
+
+#pragma weak wait4
+pid_t
+wait4(pid_t pid, int *status, int options, struct rusage *ru)
+{
+
+	return (((pid_t (*)(pid_t, int *, int, struct rusage *))
+	    __libc_interposing[INTERPOS_wait4])(pid, status, options, ru));
+}
diff --git a/lib/libc/sys/write.c b/lib/libc/sys/write.c
new file mode 100644
index 000000000000..ffb1aa5ffba7
--- /dev/null
+++ b/lib/libc/sys/write.c
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_write, __write);
+
+#pragma weak write
+ssize_t
+write(int fd, const void *buf, size_t nbytes)
+{
+
+	return (((ssize_t (*)(int, const void *, size_t))
+	    __libc_interposing[INTERPOS_write])(fd, buf, nbytes));
+}
diff --git a/lib/libc/sys/writev.c b/lib/libc/sys/writev.c
new file mode 100644
index 000000000000..6be74b3c31d1
--- /dev/null
+++ b/lib/libc/sys/writev.c
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2014 The FreeBSD Foundation.
+ * All rights reserved.
+ *
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+#include "libc_private.h"
+
+__weak_reference(__sys_writev, __writev);
+
+#pragma weak writev
+ssize_t
+writev(int fd, const struct iovec *iov, int iovcnt)
+{
+
+	return (((ssize_t (*)(int, const struct iovec *, int))
+	    __libc_interposing[INTERPOS_writev])(fd, iov, iovcnt));
+}