Index: libexec/rtld-elf/rtld.1
===================================================================
--- libexec/rtld-elf/rtld.1
+++ libexec/rtld-elf/rtld.1
@@ -143,6 +143,13 @@
 .Nm
 will print a table containing all relocations before symbol
 binding and relocation.
+.It Ev LD_DYNAMIC_WEAK
+If set to 0, use the standard symbol lookup behavior: resolve to the first
+definition, regardless of whether it is weak.
+By default the non-standard traditional symbol lookup behavior is used: when a
+weak definition is found, remember the definition and keep searching in the
+remaining shared objects for a non-weak definition. If found, the non-weak
+definition is returned, otherwise the remembered weak definition is returned.
 .It Ev LD_LIBMAP
 A library replacement list in the same format as
 .Xr libmap.conf 5 .
Index: libexec/rtld-elf/rtld.c
===================================================================
--- libexec/rtld-elf/rtld.c
+++ libexec/rtld-elf/rtld.c
@@ -209,6 +209,7 @@
 bool ld_bind_not;		/* Disable PLT update */
 static char *ld_bind_now;	/* Environment variable for immediate binding */
 static char *ld_debug;		/* Environment variable for debugging */
+static bool ld_dynamic_weak;    /* True if non-weak definition overrides weak definition */
 static char *ld_library_path;	/* Environment variable for search path */
 static char *ld_library_dirs;	/* Environment variable for library descriptors */
 static char *ld_preload;	/* Environment variable for libraries to
@@ -385,7 +386,7 @@
     RtldLockState lockstate;
     struct stat st;
     Elf_Addr *argcp;
-    char **argv, **env, **envp, *kexecpath, *library_path_rpath;
+    char **argv, **env, **envp, *kexecpath, *dynamic_weak, *library_path_rpath;
     const char *argv0, *binpath;
     caddr_t imgentry;
     char buf[MAXPATHLEN];
@@ -591,6 +592,9 @@
     ld_debug = getenv(_LD("DEBUG"));
     if (ld_bind_now == NULL)
 	    ld_bind_not = getenv(_LD("BIND_NOT")) != NULL;
+    dynamic_weak = getenv(_LD("DYNAMIC_WEAK"));
+    if (dynamic_weak != NULL)
+	ld_dynamic_weak = dynamic_weak[0] == '0' || dynamic_weak[0] == 'n';
     libmap_disable = getenv(_LD("LIBMAP_DISABLE")) != NULL;
     libmap_override = getenv(_LD("LIBMAP"));
     ld_library_path = getenv(_LD("LIBRARY_PATH"));
@@ -3673,11 +3677,11 @@
 		    continue;
 		res = symlook_obj(&req, obj);
 		if (res == 0) {
-		    if (def == NULL ||
-		      ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) {
+		    if (def == NULL || (ld_dynamic_weak &&
+                      ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK)) {
 			def = req.sym_out;
 			defobj = req.defobj_out;
-			if (ELF_ST_BIND(def->st_info) != STB_WEAK)
+			if (!ld_dynamic_weak || ELF_ST_BIND(def->st_info) != STB_WEAK)
 			    break;
 		    }
 		}
@@ -4288,10 +4292,10 @@
     symlook_init_from_req(&req1, req);
 
     /* Search all objects loaded at program start up. */
-    if (req->defobj_out == NULL ||
-      ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) {
+    if (req->defobj_out == NULL || (ld_dynamic_weak &&
+      ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK)) {
 	res = symlook_list(&req1, &list_main, donelist);
-	if (res == 0 && (req->defobj_out == NULL ||
+	if (res == 0 && (!ld_dynamic_weak || req->defobj_out == NULL ||
 	  ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
 	    req->sym_out = req1.sym_out;
 	    req->defobj_out = req1.defobj_out;
@@ -4301,8 +4305,8 @@
 
     /* Search all DAGs whose roots are RTLD_GLOBAL objects. */
     STAILQ_FOREACH(elm, &list_global, link) {
-	if (req->defobj_out != NULL &&
-	  ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)
+	if (req->defobj_out != NULL && (!ld_dynamic_weak ||
+          ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK))
 	    break;
 	res = symlook_list(&req1, &elm->obj->dagmembers, donelist);
 	if (res == 0 && (req->defobj_out == NULL ||
@@ -4351,8 +4355,8 @@
 
     /* Search all dlopened DAGs containing the referencing object. */
     STAILQ_FOREACH(elm, &refobj->dldags, link) {
-	if (req->sym_out != NULL &&
-	  ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)
+	if (req->sym_out != NULL && (!ld_dynamic_weak ||
+          ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK))
 	    break;
 	res = symlook_list(&req1, &elm->obj->dagmembers, &donelist);
 	if (res == 0 && (req->sym_out == NULL ||
@@ -4397,10 +4401,11 @@
 	    continue;
 	symlook_init_from_req(&req1, req);
 	if ((res = symlook_obj(&req1, elm->obj)) == 0) {
-	    if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) {
+	    if (def == NULL || (ld_dynamic_weak &&
+              ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
 		def = req1.sym_out;
 		defobj = req1.defobj_out;
-		if (ELF_ST_BIND(def->st_info) != STB_WEAK)
+		if (!ld_dynamic_weak || ELF_ST_BIND(def->st_info) != STB_WEAK)
 		    break;
 	    }
 	}
@@ -4435,10 +4440,11 @@
 	if (n->obj == NULL ||
 	    (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0)
 	    continue;
-	if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) {
+	if (def == NULL || (ld_dynamic_weak &&
+          ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
 	    def = req1.sym_out;
 	    defobj = req1.defobj_out;
-	    if (ELF_ST_BIND(def->st_info) != STB_WEAK)
+	    if (!ld_dynamic_weak || ELF_ST_BIND(def->st_info) != STB_WEAK)
 		break;
 	}
     }