Add more fixes for inavlid memory accesses triggered by corrupt files.

[deliverable/binutils-gdb.git] / gdb / remote.c

diff --git a/gdb/remote.c b/gdb/remote.c
index 3fa835fb115fcd7e07c2f4a72aaf557bca718d9f..4b9b0991c65ffeeb6a817824266d450a76bc406a 100644 (file)
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -1842,11 +1842,11 @@ set_general_process (void)
 }
 
 \f
-/*  Return nonzero if the thread PTID is still alive on the remote
-    system.  */
+/* Return nonzero if this is the main thread that we made up ourselves
+   to model non-threaded targets as single-threaded.  */
 
 static int
-remote_thread_alive (struct target_ops *ops, ptid_t ptid)
+remote_thread_always_alive (struct target_ops *ops, ptid_t ptid)
 {
   struct remote_state *rs = get_remote_state ();
   char *p, *endp;
@@ -1861,6 +1861,23 @@ remote_thread_alive (struct target_ops *ops, ptid_t ptid)
        multi-threading.  */
     return 1;
 
+  return 0;
+}
+
+/* Return nonzero if the thread PTID is still alive on the remote
+   system.  */
+
+static int
+remote_thread_alive (struct target_ops *ops, ptid_t ptid)
+{
+  struct remote_state *rs = get_remote_state ();
+  char *p, *endp;
+
+  /* Check if this is a thread that we made up ourselves to model
+     non-threaded targets as single-threaded.  */
+  if (remote_thread_always_alive (ops, ptid))
+    return 1;
+
   p = rs->buf;
   endp = rs->buf + get_remote_packet_size ();
 
@@ -2559,6 +2576,21 @@ struct threads_listing_context
   VEC (thread_item_t) *items;
 };
 
+/* Discard the contents of the constructed thread listing context.  */
+
+static void
+clear_threads_listing_context (void *p)
+{
+  struct threads_listing_context *context = p;
+  int i;
+  struct thread_item *item;
+
+  for (i = 0; VEC_iterate (thread_item_t, context->items, i, item); ++i)
+    xfree (item->extra);
+
+  VEC_free (thread_item_t, context->items);
+}
+
 static int
 remote_newthread_step (threadref *ref, void *data)
 {
@@ -2664,21 +2696,6 @@ const struct gdb_xml_element threads_elements[] = {
   { NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
 };
 
-/* Discard the contents of the constructed thread info context.  */
-
-static void
-clear_threads_listing_context (void *p)
-{
-  struct threads_listing_context *context = p;
-  int i;
-  struct thread_item *item;
-
-  for (i = 0; VEC_iterate (thread_item_t, context->items, i, item); ++i)
-    xfree (item->extra);
-
-  VEC_free (thread_item_t, context->items);
-}
-
 #endif
 
 /* List remote threads using qXfer:threads:read.  */
@@ -2753,15 +2770,16 @@ remote_get_threads_with_qthreadinfo (struct target_ops *ops,
   return 0;
 }
 
-/* Implement the to_find_new_threads function for the remote
+/* Implement the to_update_thread_list function for the remote
    targets.  */
 
 static void
-remote_threads_info (struct target_ops *ops)
+remote_update_thread_list (struct target_ops *ops)
 {
   struct remote_state *rs = get_remote_state ();
   struct threads_listing_context context;
   struct cleanup *old_chain;
+  int got_list = 0;
 
   context.items = NULL;
   old_chain = make_cleanup (clear_threads_listing_context, &context);
@@ -2775,8 +2793,43 @@ remote_threads_info (struct target_ops *ops)
     {
       int i;
       struct thread_item *item;
+      struct thread_info *tp, *tmp;
+
+      got_list = 1;
+
+      if (VEC_empty (thread_item_t, context.items)
+         && remote_thread_always_alive (ops, inferior_ptid))
+       {
+         /* Some targets don't really support threads, but still
+            reply an (empty) thread list in response to the thread
+            listing packets, instead of replying "packet not
+            supported".  Exit early so we don't delete the main
+            thread.  */
+         do_cleanups (old_chain);
+         return;
+       }
+
+      /* CONTEXT now holds the current thread list on the remote
+        target end.  Delete GDB-side threads no longer found on the
+        target.  */
+      ALL_NON_EXITED_THREADS_SAFE (tp, tmp)
+        {
+         for (i = 0;
+              VEC_iterate (thread_item_t, context.items, i, item);
+              ++i)
+           {
+             if (ptid_equal (item->ptid, tp->ptid))
+               break;
+           }
 
-      /* Add threads we don't know about yet to our list.  */
+         if (i == VEC_length (thread_item_t, context.items))
+           {
+             /* Not found.  */
+             delete_thread (tp->ptid);
+           }
+        }
+
+      /* And now add threads we don't know about yet to our list.  */
       for (i = 0;
           VEC_iterate (thread_item_t, context.items, i, item);
           ++i)
@@ -2800,6 +2853,15 @@ remote_threads_info (struct target_ops *ops)
        }
     }
 
+  if (!got_list)
+    {
+      /* If no thread listing method is supported, then query whether
+        each known thread is alive, one by one, with the T packet.
+        If the target doesn't support threads at all, then this is a
+        no-op.  See remote_thread_alive.  */
+      prune_threads ();
+    }
+
   do_cleanups (old_chain);
 }
 
@@ -3424,7 +3486,7 @@ remote_start_remote (int from_tty, struct target_ops *target, int extended_p)
         controlling.  We default to adding them in the running state.
         The '?' query below will then tell us about which threads are
         stopped.  */
-      remote_threads_info (target);
+      remote_update_thread_list (target);
     }
   else if (packet_support (PACKET_QNonStop) == PACKET_ENABLE)
     {
@@ -3476,7 +3538,7 @@ remote_start_remote (int from_tty, struct target_ops *target, int extended_p)
        }
 
       /* Fetch thread list.  */
-      target_find_new_threads ();
+      target_update_thread_list ();
 
       /* Let the stub know that we want it to return the thread.  */
       set_continue_thread (minus_one_ptid);
@@ -4446,7 +4508,7 @@ extended_remote_attach_1 (struct target_ops *target, const char *args,
       struct thread_info *thread;
 
       /* Get list of threads.  */
-      remote_threads_info (target);
+      remote_update_thread_list (target);
 
       thread = first_thread_of_process (pid);
       if (thread)
@@ -11456,7 +11518,7 @@ Specify the serial device it is connected to\n\
   remote_ops.to_pass_signals = remote_pass_signals;
   remote_ops.to_program_signals = remote_program_signals;
   remote_ops.to_thread_alive = remote_thread_alive;
-  remote_ops.to_find_new_threads = remote_threads_info;
+  remote_ops.to_update_thread_list = remote_update_thread_list;
   remote_ops.to_pid_to_str = remote_pid_to_str;
   remote_ops.to_extra_thread_info = remote_threads_extra_info;
   remote_ops.to_get_ada_task_ptid = remote_get_ada_task_ptid;