Index: head/lib/libc/sys/openat.c
===================================================================
--- head/lib/libc/sys/openat.c	(revision 360305)
+++ head/lib/libc/sys/openat.c	(revision 360306)
@@ -1,61 +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));
 }
Index: head/lib/libc/sys/setcontext.c
===================================================================
--- head/lib/libc/sys/setcontext.c	(revision 360305)
+++ head/lib/libc/sys/setcontext.c	(revision 360306)
@@ -1,51 +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));
 }
Index: head/lib/libc/sys/swapcontext.c
===================================================================
--- head/lib/libc/sys/swapcontext.c	(revision 360305)
+++ head/lib/libc/sys/swapcontext.c	(revision 360306)
@@ -1,52 +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));
 }