gdb/gdbserver/

	* proc-service.c (ps_pglobal_lookup): Use
	thread_db_look_up_one_symbol.
	* remote-utils.c (look_up_one_symbol): Add new `may_ask_gdb'
	parameter.  Use it instead of all_symbols_looked_up.
	* server.h (struct process_info) <all_symbols_looked_up>: Delete
	field.
	(all_symbols_looked_up): Don't declare.
	(look_up_one_symbol): Add new `may_ask_gdb' parameter.
	* thread-db.c (struct thread_db) <all_symbols_looked_up>: New
	field.
	(thread_db_look_up_symbols): Adjust call to look_up_one_symbol.
	Set all_symbols_looked_up here.
	(thread_db_look_up_one_symbol): New.
	(thread_db_get_tls_address): Adjust.
	(thread_db_load_search, try_thread_db_load_1): Always allocate the
	thread_db object on the heap, and tentatively set it in the
	process structure.
	(thread_db_init): Don't set all_symbols_looked_up here.
	* linux-low.h (thread_db_look_up_one_symbol): Declare.

1 files changed, 63 insertions, 37 deletions

diff --git a/gdb/gdbserver/thread-db.c b/gdb/gdbserver/thread-db.c
index 7dec30d..86c4e18 100644
--- a/gdb/gdbserver/thread-db.c
+++ b/gdb/gdbserver/thread-db.c
@@ -47,6 +47,11 @@ struct thread_db
   /* Connection to the libthread_db library.  */
   td_thragent_t *thread_agent;
 
+  /* If this flag has been set, we've already asked GDB for all
+     symbols we might need; assume symbol cache misses are
+     failures.  */
+  int all_symbols_looked_up;
+
 #ifndef USE_LIBTHREAD_DB_DIRECTLY
   /* Handle of the libthread_db from dlopen.  */
   void *handle;
@@ -452,7 +457,25 @@ thread_db_look_up_symbols (void)
   CORE_ADDR unused;
 
   for (sym_list = thread_db->td_symbol_list_p (); *sym_list; sym_list++)
-    look_up_one_symbol (*sym_list, &unused);
+    look_up_one_symbol (*sym_list, &unused, 1);
+
+  /* We're not interested in any other libraries loaded after this
+     point, only in symbols in libpthread.so.  */
+  thread_db->all_symbols_looked_up = 1;
+}
+
+int
+thread_db_look_up_one_symbol (const char *name, CORE_ADDR *addrp)
+{
+  struct thread_db *thread_db = current_process ()->private->thread_db;
+  int may_ask_gdb = !thread_db->all_symbols_looked_up;
+
+  /* If we've passed the call to thread_db_look_up_symbols, then
+     anything not in the cache must not exist; we're not interested
+     in any libraries loaded after that point, only in symbols in
+     libpthread.so.  It might not be an appropriate time to look
+     up a symbol, e.g. while we're trying to fetch registers.  */
+  return look_up_one_symbol (name, addrp, may_ask_gdb);
 }
 
 int
@@ -470,7 +493,7 @@ thread_db_get_tls_address (struct thread_info *thread, CORE_ADDR offset,
   thread_db = proc->private->thread_db;
 
   /* If the thread layer is not (yet) initialized, fail.  */
-  if (!proc->all_symbols_looked_up)
+  if (!thread_db->all_symbols_looked_up)
     return TD_ERR;
 
   if (thread_db->td_thr_tls_get_addr_p == NULL)
@@ -506,41 +529,41 @@ static int
 thread_db_load_search (void)
 {
   td_err_e err;
-  struct thread_db tdb;
+  struct thread_db *tdb;
   struct process_info *proc = current_process ();
 
   if (proc->private->thread_db != NULL)
     fatal ("unexpected: proc->private->thread_db != NULL");
 
-  memset (&tdb, 0, sizeof (tdb));
+  tdb = xcalloc (1, sizeof (*tdb));
+  proc->private->thread_db = tdb;
 
-  tdb.td_ta_new_p = &td_ta_new;
+  tdb->td_ta_new_p = &td_ta_new;
 
   /* Attempt to open a connection to the thread library.  */
-  err = tdb.td_ta_new_p (&tdb.proc_handle, &tdb.thread_agent);
+  err = tdb->td_ta_new_p (&tdb->proc_handle, &tdb->thread_agent);
   if (err != TD_OK)
     {
       if (debug_threads)
 	fprintf (stderr, "td_ta_new(): %s\n", thread_db_err_str (err));
+      free (tdb);
+      proc->private->thread_db = NULL;
       return 0;
     }
 
-  tdb.td_ta_map_lwp2thr_p = &td_ta_map_lwp2thr;
-  tdb.td_thr_get_info_p = &td_thr_get_info;
-  tdb.td_ta_thr_iter_p = &td_ta_thr_iter;
-  tdb.td_symbol_list_p = &td_symbol_list;
+  tdb->td_ta_map_lwp2thr_p = &td_ta_map_lwp2thr;
+  tdb->td_thr_get_info_p = &td_thr_get_info;
+  tdb->td_ta_thr_iter_p = &td_ta_thr_iter;
+  tdb->td_symbol_list_p = &td_symbol_list;
 
   /* This is required only when thread_db_use_events is on.  */
-  tdb.td_thr_event_enable_p = &td_thr_event_enable;
+  tdb->td_thr_event_enable_p = &td_thr_event_enable;
 
   /* These are not essential.  */
-  tdb.td_ta_event_addr_p = &td_ta_event_addr;
-  tdb.td_ta_set_event_p = &td_ta_set_event;
-  tdb.td_ta_event_getmsg_p = &td_ta_event_getmsg;
-  tdb.td_thr_tls_get_addr_p = &td_thr_tls_get_addr;
-
-  proc->private->thread_db = xmalloc (sizeof (tdb));
-  memcpy (proc->private->thread_db, &tdb, sizeof (tdb));
+  tdb->td_ta_event_addr_p = &td_ta_event_addr;
+  tdb->td_ta_set_event_p = &td_ta_set_event;
+  tdb->td_ta_event_getmsg_p = &td_ta_event_getmsg;
+  tdb->td_thr_tls_get_addr_p = &td_thr_tls_get_addr;
 
   return 1;
 }
@@ -551,15 +574,16 @@ static int
 try_thread_db_load_1 (void *handle)
 {
   td_err_e err;
-  struct thread_db tdb;
+  struct thread_db *tdb;
   struct process_info *proc = current_process ();
 
   if (proc->private->thread_db != NULL)
     fatal ("unexpected: proc->private->thread_db != NULL");
 
-  memset (&tdb, 0, sizeof (tdb));
+  tdb = xcalloc (1, sizeof (*tdb));
+  proc->private->thread_db = tdb;
 
-  tdb.handle = handle;
+  tdb->handle = handle;
 
   /* Initialize pointers to the dynamic library functions we will use.
      Essential functions first.  */
@@ -572,42 +596,45 @@ try_thread_db_load_1 (void *handle)
 	  if (debug_threads)					\
 	    fprintf (stderr, "dlsym: %s\n", dlerror ());	\
 	  if (required)						\
-	    return 0;						\
+	    {							\
+	      free (tdb);					\
+	      proc->private->thread_db = NULL;			\
+	      return 0;						\
+	    }							\
 	}							\
     }								\
   while (0)
 
-  CHK (1, tdb.td_ta_new_p = dlsym (handle, "td_ta_new"));
+  CHK (1, tdb->td_ta_new_p = dlsym (handle, "td_ta_new"));
 
   /* Attempt to open a connection to the thread library.  */
-  err = tdb.td_ta_new_p (&tdb.proc_handle, &tdb.thread_agent);
+  err = tdb->td_ta_new_p (&tdb->proc_handle, &tdb->thread_agent);
   if (err != TD_OK)
     {
       if (debug_threads)
 	fprintf (stderr, "td_ta_new(): %s\n", thread_db_err_str (err));
+      free (tdb);
+      proc->private->thread_db = NULL;
       return 0;
     }
 
-  CHK (1, tdb.td_ta_map_lwp2thr_p = dlsym (handle, "td_ta_map_lwp2thr"));
-  CHK (1, tdb.td_thr_get_info_p = dlsym (handle, "td_thr_get_info"));
-  CHK (1, tdb.td_ta_thr_iter_p = dlsym (handle, "td_ta_thr_iter"));
-  CHK (1, tdb.td_symbol_list_p = dlsym (handle, "td_symbol_list"));
+  CHK (1, tdb->td_ta_map_lwp2thr_p = dlsym (handle, "td_ta_map_lwp2thr"));
+  CHK (1, tdb->td_thr_get_info_p = dlsym (handle, "td_thr_get_info"));
+  CHK (1, tdb->td_ta_thr_iter_p = dlsym (handle, "td_ta_thr_iter"));
+  CHK (1, tdb->td_symbol_list_p = dlsym (handle, "td_symbol_list"));
 
   /* This is required only when thread_db_use_events is on.  */
   CHK (thread_db_use_events,
-       tdb.td_thr_event_enable_p = dlsym (handle, "td_thr_event_enable"));
+       tdb->td_thr_event_enable_p = dlsym (handle, "td_thr_event_enable"));
 
   /* These are not essential.  */
-  CHK (0, tdb.td_ta_event_addr_p = dlsym (handle, "td_ta_event_addr"));
-  CHK (0, tdb.td_ta_set_event_p = dlsym (handle, "td_ta_set_event"));
-  CHK (0, tdb.td_ta_event_getmsg_p = dlsym (handle, "td_ta_event_getmsg"));
-  CHK (0, tdb.td_thr_tls_get_addr_p = dlsym (handle, "td_thr_tls_get_addr"));
+  CHK (0, tdb->td_ta_event_addr_p = dlsym (handle, "td_ta_event_addr"));
+  CHK (0, tdb->td_ta_set_event_p = dlsym (handle, "td_ta_set_event"));
+  CHK (0, tdb->td_ta_event_getmsg_p = dlsym (handle, "td_ta_event_getmsg"));
+  CHK (0, tdb->td_thr_tls_get_addr_p = dlsym (handle, "td_thr_tls_get_addr"));
 
 #undef CHK
 
-  proc->private->thread_db = xmalloc (sizeof (tdb));
-  memcpy (proc->private->thread_db, &tdb, sizeof (tdb));
-
   return 1;
 }
 
@@ -763,7 +790,6 @@ thread_db_init (int use_events)
 	}
       thread_db_find_new_threads ();
       thread_db_look_up_symbols ();
-      proc->all_symbols_looked_up = 1;
       return 1;
     }