Re: A patch for the unversioned lookup

["H . J . Lu" <hjl at lucon dot org>]

On Thu, May 03, 2001 at 11:14:02PM -0700, H . J . Lu wrote:
> > 
> 
> That is incorrect. Here is a new one. I will send a patch for a new
> testcase in glibc.
> 
> 

Here is an update. I modified do_lookup to return version name and
print it out if asked. It is useful to know which vesion of an
unversioned symbol is bound to.

H.J.
----
2001-05-04  H.J. Lu  <hjl@gnu.org>

	* elf/dl-lookup.c (_dl_lookup_symbol): Get version name from
	do_lookup and print it out if asked.
	(_dl_lookup_symbol_skip): Likewise.

	* do-lookup.h (do_lookup): Return version name. Fix the
	unversioned lookup against the nono-default version definition.

--- libc/elf/dl-lookup.c.nodef	Tue Feb 27 22:22:10 2001
+++ libc/elf/dl-lookup.c	Fri May  4 09:10:30 2001
@@ -197,13 +197,14 @@ _dl_lookup_symbol (const char *undef_nam
   int protected;
   int noexec = elf_machine_lookup_noexec_p (reloc_type);
   int noplt = elf_machine_lookup_noplt_p (reloc_type);
+  const char *version_name = NULL;
 
   ++_dl_num_relocations;
 
   /* Search the relevant loaded objects for a definition.  */
   for (scope = symbol_scope; *scope; ++scope)
-    if (do_lookup (undef_name, hash, *ref, &current_value, *scope, 0, NULL,
-		   noexec, noplt))
+    if (do_lookup (undef_name, hash, *ref, &current_value, *scope, 0,
+		   &version_name, NULL, noexec, noplt))
       {
 	/* We have to check whether this would bind UNDEF_MAP to an object
 	   in the global scope which was dynamically loaded.  In this case
@@ -242,12 +243,13 @@ _dl_lookup_symbol (const char *undef_nam
   protected = *ref && ELFW(ST_VISIBILITY) ((*ref)->st_other) == STV_PROTECTED;
 
   if (__builtin_expect (_dl_debug_mask & DL_DEBUG_BINDINGS, 0))
-    _dl_debug_printf ("binding file %s to %s: %s symbol `%s'\n",
+    _dl_debug_printf ("binding file %s to %s: %s symbol `%s' [%s]\n",
 		      (reference_name && reference_name[0]
 		       ? reference_name : (_dl_argv[0] ?: "<main program>")),
 		       current_value.m->l_name[0]
 		       ? current_value.m->l_name : _dl_argv[0],
-		       protected ? "protected" : "normal", undef_name);
+		       protected ? "protected" : "normal", undef_name,
+		       version_name ?: "Base");
 
   if (__builtin_expect (protected == 0, 1))
     {
@@ -262,7 +264,7 @@ _dl_lookup_symbol (const char *undef_nam
 
       for (scope = symbol_scope; *scope; ++scope)
 	if (do_lookup (undef_name, hash, *ref, &protected_value, *scope, 0,
-		       NULL, 0, 1))
+		       &version_name, NULL, 0, 1))
 	  break;
 
       if (protected_value.s == NULL || protected_value.m == undef_map)
@@ -294,6 +296,7 @@ _dl_lookup_symbol_skip (const char *unde
   struct r_scope_elem **scope;
   size_t i;
   int protected;
+  const char *version_name = NULL;
 
   ++_dl_num_relocations;
 
@@ -304,10 +307,10 @@ _dl_lookup_symbol_skip (const char *unde
 
   if (i >= (*scope)->r_nlist
 	 || ! do_lookup (undef_name, hash, *ref, &current_value, *scope, i,
-			 skip_map, 0, 0))
+			 &version_name, skip_map, 0, 0))
     while (*++scope)
       if (do_lookup (undef_name, hash, *ref, &current_value, *scope, 0,
-		     skip_map, 0, 0))
+		     &version_name, skip_map, 0, 0))
 	break;
 
   if (__builtin_expect (current_value.s == NULL, 0))
@@ -319,12 +322,13 @@ _dl_lookup_symbol_skip (const char *unde
   protected = *ref && ELFW(ST_VISIBILITY) ((*ref)->st_other) == STV_PROTECTED;
 
   if (__builtin_expect (_dl_debug_mask & DL_DEBUG_BINDINGS, 0))
-    _dl_debug_printf ("binding file %s to %s: %s symbol `%s'\n",
+    _dl_debug_printf ("binding file %s to %s: %s symbol `%s' [%s]\n",
 		       (reference_name && reference_name[0]
 			? reference_name : (_dl_argv[0] ?: "<main program>")),
 		       current_value.m->l_name[0]
 		       ? current_value.m->l_name : _dl_argv[0],
-		       protected ? "protected" : "normal", undef_name);
+		       protected ? "protected" : "normal", undef_name,
+		       version_name ?: "Base");
 
   if (__builtin_expect (protected == 0, 1))
     {
@@ -339,10 +343,10 @@ _dl_lookup_symbol_skip (const char *unde
 
       if (i >= (*scope)->r_nlist
 	  || !do_lookup (undef_name, hash, *ref, &protected_value, *scope, i,
-			 skip_map, 0, 1))
+			 &version_name, skip_map, 0, 1))
 	while (*++scope)
 	  if (do_lookup (undef_name, hash, *ref, &protected_value, *scope, 0,
-			 skip_map, 0, 1))
+			 &version_name, skip_map, 0, 1))
 	    break;
 
       if (protected_value.s == NULL || protected_value.m == undef_map)
--- libc/elf/do-lookup.h.nodef	Tue Feb 27 22:22:10 2001
+++ libc/elf/do-lookup.h	Fri May  4 09:05:52 2001
@@ -22,7 +22,7 @@
 # define ARG const struct r_found_version *const version,
 #else
 # define FCT do_lookup
-# define ARG
+# define ARG const char **version_name,
 #endif
 
 /* Inner part of the lookup functions.  We return a value > 0 if we
@@ -125,13 +125,25 @@ FCT (const char *undef_name, unsigned lo
 	  if (verstab != NULL)
 	    {
 	      ElfW(Half) ndx = verstab[symidx] & 0x7fff;
-	      if (ndx > 2) /* map->l_versions[ndx].hash != 0) */
+	      if (ndx > 1) /* map->l_versions[ndx].hash != 0) */
 		{
-		  /* Don't accept hidden symbols.  */
-		  if ((verstab[symidx] & 0x8000) == 0 && num_versions++ == 0)
-		    /* No version so far.  */
-		    versioned_sym = sym;
-		  continue;
+		  if ((verstab[symidx] & 0x8000) == 0)
+		    {
+		      /* We found the default version.  */
+		      *version_name = map->l_versions[ndx].name;
+		      goto found_it;
+		    }
+		  else
+		    {
+		      /* We found a hidden symbol. Only one version is
+			 allowed.  */
+		      if (num_versions++ == 0)
+			{
+			  versioned_sym = sym;
+			  *version_name = map->l_versions[ndx].name;
+			}
+		      continue;
+		    }
 		}
 	    }
 #endif