Index: contrib/mdocml/lib.in
===================================================================
--- contrib/mdocml/lib.in
+++ contrib/mdocml/lib.in
@@ -46,6 +46,7 @@
 LINE("libdevinfo",	"Device and Resource Information Utility Library (libdevinfo, \\-ldevinfo)")
 LINE("libdevstat",	"Device Statistics Library (libdevstat, \\-ldevstat)")
 LINE("libdisk",		"Interface to Slice and Partition Labels Library (libdisk, \\-ldisk)")
+LINE("libdl",		"Dynamic Linker Services Filter (libdl, \\-ldl)")
 LINE("libdm",		"Device Mapper Library (libdm, \\-ldm)")
 LINE("libdwarf",	"DWARF Access Library (libdwarf, \\-ldwarf)")
 LINE("libedit",		"Command Line Editor Library (libedit, \\-ledit)")
Index: lib/Makefile
===================================================================
--- lib/Makefile
+++ lib/Makefile
@@ -40,6 +40,7 @@
 	libdevctl \
 	libdevinfo \
 	libdevstat \
+	libdl \
 	libdwarf \
 	libedit \
 	libevent \
Index: lib/libc/gen/dlfcn.c
===================================================================
--- lib/libc/gen/dlfcn.c
+++ lib/libc/gen/dlfcn.c
@@ -27,6 +27,8 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+#if !defined(IN_LIBDL) || defined(PIC)
+
 /*
  * Linkage to services provided by the dynamic linker.
  */
@@ -57,95 +59,107 @@
 
 #pragma weak _rtld_error
 void
-_rtld_error(const char *fmt, ...)
+_rtld_error(const char *fmt __unused, ...)
 {
 }
 
 #pragma weak dladdr
 int
-dladdr(const void *addr, Dl_info *dlip)
+dladdr(const void *addr __unused, Dl_info *dlip __unused)
 {
+
 	_rtld_error(sorry);
-	return 0;
+	return (0);
 }
 
 #pragma weak dlclose
 int
-dlclose(void *handle)
+dlclose(void *handle __unused)
 {
+
 	_rtld_error(sorry);
-	return -1;
+	return (-1);
 }
 
 #pragma weak dlerror
 char *
 dlerror(void)
 {
-	return sorry;
+
+	return (sorry);
 }
 
 #pragma weak dllockinit
 void
 dllockinit(void *context,
-	   void *(*lock_create)(void *context),
-	   void (*rlock_acquire)(void *lock),
-	   void (*wlock_acquire)(void *lock),
-	   void (*lock_release)(void *lock),
-	   void (*lock_destroy)(void *lock),
-	   void (*context_destroy)(void *context))
+    void *(*lock_create)(void *context) __unused,
+    void (*rlock_acquire)(void *lock) __unused,
+    void (*wlock_acquire)(void *lock) __unused,
+    void (*lock_release)(void *lock) __unused,
+    void (*lock_destroy)(void *lock) __unused,
+    void (*context_destroy)(void *context) __unused)
 {
+
 	if (context_destroy != NULL)
 		context_destroy(context);
 }
 
 #pragma weak dlopen
 void *
-dlopen(const char *name, int mode)
+dlopen(const char *name __unused, int mode __unused)
 {
+
 	_rtld_error(sorry);
-	return NULL;
+	return (NULL);
 }
 
 #pragma weak dlsym
 void *
-dlsym(void * __restrict handle, const char * __restrict name)
+dlsym(void * __restrict handle __unused, const char * __restrict name __unused)
 {
+
 	_rtld_error(sorry);
-	return NULL;
+	return (NULL);
 }
 
 #pragma weak dlfunc
 dlfunc_t
-dlfunc(void * __restrict handle, const char * __restrict name)
+dlfunc(void * __restrict handle __unused, const char * __restrict name __unused)
 {
+
 	_rtld_error(sorry);
-	return NULL;
+	return (NULL);
 }
 
 #pragma weak dlvsym
 void *
-dlvsym(void * __restrict handle, const char * __restrict name,
-    const char * __restrict version)
+dlvsym(void * __restrict handle __unused, const char * __restrict name __unused,
+    const char * __restrict version __unused)
 {
+
 	_rtld_error(sorry);
-	return NULL;
+	return (NULL);
 }
 
 #pragma weak dlinfo
 int
-dlinfo(void * __restrict handle, int request, void * __restrict p)
+dlinfo(void * __restrict handle __unused, int request __unused,
+    void * __restrict p __unused)
 {
+
 	_rtld_error(sorry);
-	return 0;
+	return (0);
 }
 
 #pragma weak _rtld_thread_init
 void
-_rtld_thread_init(void * li)
+_rtld_thread_init(void *li __unused)
 {
+
 	_rtld_error(sorry);
 }
 
+#ifndef IN_LIBDL
 static pthread_once_t dl_phdr_info_once = PTHREAD_ONCE_INIT;
 static struct dl_phdr_info phdr_info;
 
@@ -181,44 +195,50 @@
 	}
 	phdr_info.dlpi_adds = 1;
 }
+#endif
 
 #pragma weak dl_iterate_phdr
 int
-dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *),
-    void *data)
+dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *) __unused,
+    void *data __unused)
 {
 
+#ifndef IN_LIBDL
 	__init_elf_aux_vector();
 	if (__elf_aux_vector == NULL)
 		return (1);
 	_once(&dl_phdr_info_once, dl_init_phdr_info);
 	return (callback(&phdr_info, sizeof(phdr_info), data));
+#else
+	return (0);
+#endif
 }
 
 #pragma weak fdlopen
 void *
-fdlopen(int fd, int mode)
+fdlopen(int fd __unused, int mode __unused)
 {
 
 	_rtld_error(sorry);
-	return NULL;
+	return (NULL);
 }
 
 #pragma weak _rtld_atfork_pre
 void
-_rtld_atfork_pre(int *locks)
+_rtld_atfork_pre(int *locks __unused)
 {
 }
 
 #pragma weak _rtld_atfork_post
 void
-_rtld_atfork_post(int *locks)
+_rtld_atfork_post(int *locks __unused)
 {
 }
 
 #pragma weak _rtld_addr_phdr
 int
-_rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info)
+_rtld_addr_phdr(const void *addr __unused,
+    struct dl_phdr_info *phdr_info_a __unused)
 {
 
 	return (0);
@@ -234,8 +254,10 @@
 
 #pragma weak _rtld_is_dlopened
 int
-_rtld_is_dlopened(void *arg)
+_rtld_is_dlopened(void *arg __unused)
 {
 
 	return (0);
 }
+
+#endif /* !defined(IN_LIBDL) || defined(PIC) */
Index: lib/libc/gen/dlopen.3
===================================================================
--- lib/libc/gen/dlopen.3
+++ lib/libc/gen/dlopen.3
@@ -32,7 +32,7 @@
 .\" @(#) dlopen.3 1.6 90/01/31 SMI
 .\" $FreeBSD$
 .\"
-.Dd February 14, 2015
+.Dd July 7, 2017
 .Dt DLOPEN 3
 .Os
 .Sh NAME
@@ -377,6 +377,14 @@
 for symbols defined in the executable to become visible to
 .Fn dlsym .
 .Pp
+Other ELF platforms require linking with
+.Lb libdl
+to get the
+.Fn dlopen
+and other functions accessible.
+.Fx
+does not require linking with the library, but supports it for compatibility.
+.Pp
 In previous implementations, it was necessary to prepend an underscore
 to all external symbols in order to gain symbol
 compatibility with object code compiled from the C language.
Index: lib/libdl/Makefile
===================================================================
--- /dev/null
+++ lib/libdl/Makefile
@@ -0,0 +1,15 @@
+# $FreeBSD$
+
+LIB=dl
+SHLIB_MAJOR=1
+
+.PATH:	${SRCTOP}/lib/libc/gen
+CFLAGS+=-I${SRCTOP}/lib/libc/include
+CFLAGS+=-DIN_LIBDL
+LDFLAGS+=-Wl,--filter=libc.so.7
+VERSION_DEF=${SRCTOP}/lib/libc/Versions.def
+SYMBOL_MAPS=${.CURDIR}/Symbol.map
+
+SRCS =	dlfcn.c
+
+.include <bsd.lib.mk>
Index: lib/libdl/Symbol.map
===================================================================
--- /dev/null
+++ lib/libdl/Symbol.map
@@ -0,0 +1,20 @@
+/*
+ * $FreeBSD$
+ */
+
+FBSD_1.0 {
+	dladdr;
+	dlclose;
+	dlerror;
+	dlfunc;
+	dlopen;
+	dlsym;
+	dlvsym;
+	dlinfo;
+	dl_iterate_phdr;
+};
+
+
+FBSD_1.3 {
+	fdlopen;
+};
Index: share/mk/bsd.libnames.mk
===================================================================
--- share/mk/bsd.libnames.mk
+++ share/mk/bsd.libnames.mk
@@ -56,6 +56,7 @@
 LIBDEVINFO?=	${LIBDESTDIR}${LIBDIR_BASE}/libdevinfo.a
 LIBDEVSTAT?=	${LIBDESTDIR}${LIBDIR_BASE}/libdevstat.a
 LIBDIALOG?=	${LIBDESTDIR}${LIBDIR_BASE}/libdialog.a
+LIBDL?=		${LIBDESTDIR}${LIBDIR_BASE}/libdl.a
 LIBDNS?=	${LIBDESTDIR}${LIBDIR_BASE}/libdns.a
 LIBDPV?=	${LIBDESTDIR}${LIBDIR_BASE}/libdpv.a
 LIBDTRACE?=	${LIBDESTDIR}${LIBDIR_BASE}/libdtrace.a
Index: share/mk/src.libnames.mk
===================================================================
--- share/mk/src.libnames.mk
+++ share/mk/src.libnames.mk
@@ -88,6 +88,7 @@
 		devinfo \
 		devstat \
 		dialog \
+		dl \
 		dpv \
 		dtrace \
 		dwarf \