Index: head/libexec/rtld-elf/rtld.c
===================================================================
--- head/libexec/rtld-elf/rtld.c
+++ head/libexec/rtld-elf/rtld.c
@@ -2272,8 +2272,10 @@
     parse_rtld_phdr(&obj_rtld);
     obj_enforce_relro(&obj_rtld);
 
+    r_debug.r_version = R_DEBUG_VERSION;
     r_debug.r_brk = r_debug_state;
     r_debug.r_state = RT_CONSISTENT;
+    r_debug.r_ldbase = obj_rtld.relocbase;
 }
 
 /*
Index: head/sys/sys/link_elf.h
===================================================================
--- head/sys/sys/link_elf.h
+++ head/sys/sys/link_elf.h
@@ -69,7 +69,7 @@
 } Link_map;
 
 struct r_debug {
-	int		r_version;		/* not used */
+	int		r_version;		/* Currently '1' */
 	struct link_map *r_map;			/* list of loaded images */
 	void		(*r_brk)(struct r_debug *, struct link_map *);
 						/* pointer to break point */
@@ -78,7 +78,10 @@
 		RT_ADD,				/* adding a shared library */
 		RT_DELETE			/* removing a shared library */
 	}		r_state;
+	void		*r_ldbase;		/* Base address of rtld */
 };
+
+#define	R_DEBUG_VERSION		1
 
 struct dl_phdr_info
 {