*** empty log message ***

[deliverable/binutils-gdb.git] / gdb / solib-svr4.c

diff --git a/gdb/solib-svr4.c b/gdb/solib-svr4.c
index 9637db92dc3f7ba4c9a79916ae9d938c8792cd80..55a2280dcd0bf8be43a2d2b38eed9535b26de3aa 100644 (file)
--- a/gdb/solib-svr4.c
+++ b/gdb/solib-svr4.c
@@ -1,8 +1,7 @@
 /* Handle SVR4 shared libraries for GDB, the GNU Debugger.
 
-   Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999,
-   2000, 2001, 2003, 2004, 2005, 2006
-   Free Software Foundation, Inc.
+   Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000,
+   2001, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
 
    This file is part of GDB.
 
@@ -267,6 +266,15 @@ IGNORE_FIRST_LINK_MAP_ENTRY (struct so_list *so)
 static CORE_ADDR debug_base;   /* Base of dynamic linker structures */
 static CORE_ADDR breakpoint_addr;      /* Address where end bkpt is set */
 
+/* Validity flag for debug_loader_offset.  */
+static int debug_loader_offset_p;
+
+/* Load address for the dynamic linker, inferred.  */
+static CORE_ADDR debug_loader_offset;
+
+/* Name of the dynamic linker, valid if debug_loader_offset_p.  */
+static char *debug_loader_name;
+
 /* Local function prototypes */
 
 static int match_main (char *);
@@ -657,6 +665,37 @@ open_symbol_file_object (void *from_ttyp)
   return 1;
 }
 
+/* If no shared library information is available from the dynamic
+   linker, build a fallback list from other sources.  */
+
+static struct so_list *
+svr4_default_sos (void)
+{
+  struct so_list *head = NULL;
+  struct so_list **link_ptr = &head;
+
+  if (debug_loader_offset_p)
+    {
+      struct so_list *new = XZALLOC (struct so_list);
+
+      new->lm_info = xmalloc (sizeof (struct lm_info));
+
+      /* Nothing will ever check the cached copy of the link
+        map if we set l_addr.  */
+      new->lm_info->l_addr = debug_loader_offset;
+      new->lm_info->lm = NULL;
+
+      strncpy (new->so_name, debug_loader_name, SO_NAME_MAX_PATH_SIZE - 1);
+      new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
+      strcpy (new->so_original_name, new->so_name);
+
+      *link_ptr = new;
+      link_ptr = &new->next;
+    }
+
+  return head;
+}
+
 /* LOCAL FUNCTION
 
    current_sos -- build a list of currently loaded shared objects
@@ -693,12 +732,13 @@ svr4_current_sos (void)
       /* If we can't find the dynamic linker's base structure, this
         must not be a dynamically linked executable.  Hmm.  */
       if (! debug_base)
-       return 0;
+       return svr4_default_sos ();
     }
 
   /* Walk the inferior's link map list, and build our list of
      `struct so_list' nodes.  */
   lm = solib_svr4_r_map ();
+
   while (lm)
     {
       struct link_map_offsets *lmo = svr4_fetch_link_map_offsets ();
@@ -765,6 +805,9 @@ svr4_current_sos (void)
       discard_cleanups (old_chain);
     }
 
+  if (head == NULL)
+    return svr4_default_sos ();
+
   return head;
 }
 
@@ -983,7 +1026,12 @@ enable_break (void)
          be trivial on GNU/Linux).  Therefore, we have to try an alternate
          mechanism to find the dynamic linker's base address.  */
 
-      tmp_fd  = solib_open (buf, &tmp_pathname);
+      /* TODO drow/2006-09-12: This is somewhat fragile, because it
+        relies on read_pc.  On both Solaris and GNU/Linux we can use
+        the AT_BASE auxilliary entry, which GDB now knows how to
+        access, to find the base address.  */
+
+      tmp_fd = solib_open (buf, &tmp_pathname);
       if (tmp_fd >= 0)
        tmp_bfd = bfd_fopen (tmp_pathname, gnutarget, FOPEN_RB, tmp_fd);
 
@@ -1022,8 +1070,14 @@ enable_break (void)
         the current pc (which should point at the entry point for the
         dynamic linker) and subtracting the offset of the entry point.  */
       if (!load_addr_found)
-       load_addr = (read_pc ()
-                    - exec_entry_point (tmp_bfd, tmp_bfd_target));
+       {
+         load_addr = (read_pc ()
+                      - exec_entry_point (tmp_bfd, tmp_bfd_target));
+         debug_loader_name = xstrdup (buf);
+         debug_loader_offset_p = 1;
+         debug_loader_offset = load_addr;
+         solib_add (NULL, 0, NULL, auto_solib_add);
+       }
 
       /* Record the relocated start and end address of the dynamic linker
          text and plt section for svr4_in_dynsym_resolve_code.  */
@@ -1335,6 +1389,10 @@ static void
 svr4_clear_solib (void)
 {
   debug_base = 0;
+  debug_loader_offset_p = 0;
+  debug_loader_offset = 0;
+  xfree (debug_loader_name);
+  debug_loader_name = NULL;
 }
 
 static void