From cefbc49679b2a5563d64cc46b3a9671d88727539 Mon Sep 17 00:00:00 2001
From: John Polstra <jdp@FreeBSD.org>
Date: Wed, 2 Sep 1998 01:09:34 +0000
Subject: Handle dlsym(NULL, ...) properly, by searching in the caller's shared
 object.  Note, this searches _only_ that object, and not its needed objects,
 in accordance with the documentation.

Also fix dlopen(NULL, ...) so that the executable's needed objects
are searched as well as the executable itself.
---
 libexec/rtld-elf/rtld.c | 37 ++++++++++++++++++++++++++-----------
 1 file changed, 26 insertions(+), 11 deletions(-)

(limited to 'libexec')

diff --git a/libexec/rtld-elf/rtld.c b/libexec/rtld-elf/rtld.c
index e233c513d4c3..eb5b6052477a 100644
--- a/libexec/rtld-elf/rtld.c
+++ b/libexec/rtld-elf/rtld.c
@@ -22,7 +22,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- *      $Id: rtld.c,v 1.2 1998/04/30 07:48:00 dfr Exp $
+ *      $Id: rtld.c,v 1.3 1998/05/01 08:39:27 dfr Exp $
  */
 
 /*
@@ -126,6 +126,8 @@ static char *ld_bind_now;	/* Environment variable for immediate binding */
 static char *ld_debug;		/* Environment variable for debugging */
 static char *ld_library_path;	/* Environment variable for search path */
 static char *ld_tracing;	/* Called from ldd to print libs */
+static Obj_Entry **main_tail;	/* Value of obj_tail after loading main and
+				   its needed shared libraries */
 static Obj_Entry *obj_list;	/* Head of linked list of shared objects */
 static Obj_Entry **obj_tail;	/* Link field of last object in list */
 static Obj_Entry *obj_main;	/* The main program shared object */
@@ -268,6 +270,7 @@ _rtld(Elf32_Word *sp, func_ptr_type *exit_proc)
     dbg("loading needed objects");
     if (load_needed_objects(obj_main) == -1)
 	die();
+    main_tail = obj_tail;
 
     if (ld_tracing) {		/* We're done */
 	trace_loaded_objects(obj_main);
@@ -1239,8 +1242,9 @@ dlsym(void *handle, const char *name)
     const Elf32_Sym *def;
 
     hash = elf_hash(name);
+    def = NULL;
 
-    if (handle == RTLD_NEXT) {
+    if (handle == NULL || handle == RTLD_NEXT) {
 	void *retaddr;
 
 	retaddr = __builtin_return_address(0);	/* __GNUC__ only */
@@ -1248,18 +1252,29 @@ dlsym(void *handle, const char *name)
 	    _rtld_error("Cannot determine caller's shared object");
 	    return NULL;
 	}
-	def = NULL;
-	while ((obj = obj->next) != NULL)
-	    if ((def = symlook_obj(name, hash, obj, true)) != NULL)
-		break;
+	if (handle == NULL)	/* Just the caller's shared object. */
+	    def = symlook_obj(name, hash, obj, true);
+	else {			/* All the shared objects after the caller's */
+	    while ((obj = obj->next) != NULL)
+		if ((def = symlook_obj(name, hash, obj, true)) != NULL)
+		    break;
+	}
     } else {
 	if ((obj = dlcheck(handle)) == NULL)
 	    return NULL;
-	/*
-	 * XXX - This isn't correct.  The search should include the whole
-	 * DAG rooted at the given object.
-	 */
-	def = symlook_obj(name, hash, obj, true);
+
+	if (obj->mainprog) {
+	    /* Search main program and all libraries loaded by it. */
+	    for ( ;  obj != *main_tail;  obj = obj->next)
+		if ((def = symlook_obj(name, hash, obj, true)) != NULL)
+		    break;
+	} else {
+	    /*
+	     * XXX - This isn't correct.  The search should include the whole
+	     * DAG rooted at the given object.
+	     */
+	    def = symlook_obj(name, hash, obj, true);
+	}
     }
 
     if (def != NULL)
-- 
cgit v1.3