target remote and multiprocess+

Message ID 583D9998.5030603@marco.de
State New, archived
Headers

Commit Message

Matthias Pfaller Nov. 29, 2016, 3:07 p.m. UTC
  Hi,

This patch does:
(1) make "multiprocess+;" work with "target remote"
(2) stop inferiors only for the event thread when a break or watch point
is hit
(3) stop new inferiors only when global break or watch points are in place

This makes it possible to debug an embedded target where gdbserver is
running as native thread on the target. The target has to report the
threadlist as an inferiorlist with one thread per inferior. That way one
can context switch break and watch points and halt only the thread to be
debugged.

Without (2) and (3) the gdbstub on the target would get stopped when
connecting...

Per advice of Luis Machado I did run

  make check >check.out 2>&1
and
  make check-gdb RUNTESTFLAGS="--target_board native-gdbserver"
>check2.out 2>&1

I then did a "grep FAILED | sort" on the outputs of an unmodified
gdb-7.12 and a gdb-7.12 bult with my patch.
A diff between both sets of output didn't show up any new FAILED lines.

regards, Matthias
  

Patch

--- ../orig/gdb/breakpoint.c
+++ ./gdb/breakpoint.c
--- ../orig/gdb/infcmd.c
+++ ./gdb/infcmd.c
@@ -2741,7 +2741,7 @@ 
 	  struct thread_info *lowest = inferior_thread ();
 	  int pid = current_inferior ()->pid;
 
-	  stop_all_threads ();
+	  stop_all_threads (inferior);
 
 	  /* It's not defined which thread will report the attach
 	     stop.  For consistency, always select the thread with
@@ -2920,6 +2920,28 @@ 
   attach_post_wait (args, from_tty, mode);
 }
 
+/* Helper function for any_global_breakpoint.  If B is a global
+   break or catch point, return 1 (which will make
+   'breakpoint_find_if' return).  Otherwise, return 0.  */
+
+static int
+any_global_breakpoint_1 (struct breakpoint *b,
+			   void *data)
+{
+  if (b->enable_state == bp_enabled && b->thread == -1)
+    return 1;
+  else
+    return 0;
+}
+
+static int
+any_global_breakpoint (void)
+{
+  struct breakpoint *b = breakpoint_find_if (any_global_breakpoint_1, NULL);
+
+  return b != NULL;
+}
+
 /* We had just found out that the target was already attached to an
    inferior.  PTID points at a thread of this new inferior, that is
    the most likely to be stopped right now, but not necessarily so.
@@ -2948,7 +2970,9 @@ 
   /* When we "notice" a new inferior we need to do all the things we
      would normally do if we had just attached to it.  */
 
-  if (is_executing (inferior_ptid))
+  if (!leave_running &&
+      any_global_breakpoint () &&
+      is_executing (inferior_ptid))
     {
       struct attach_command_continuation_args *a;
       struct inferior *inferior = current_inferior ();
--- ../orig/gdb/inferior.c
+++ ./gdb/inferior.c
@@ -320,13 +320,27 @@ 
 void
 discard_all_inferiors (void)
 {
-  struct inferior *inf;
+  struct inferior *inf, *infnext;
 
-  for (inf = inferior_list; inf; inf = inf->next)
+  for (inf = inferior_list; inf; inf = infnext)
     {
-      if (inf->pid != 0)
-	exit_inferior_silent (inf->pid);
+      infnext = inf->next;
+      
+      if (inf->num == 1)
+        {
+	  if (inf->pid != 0)
+	    exit_inferior_1 (inf, 1);
+	}
+      else
+	delete_inferior (inf);
     }
+
+  inferior_ptid = null_ptid;
+  inferior_list->pid = 0;
+  set_current_inferior (inferior_list);
+  switch_to_thread (null_ptid);
+
+  highest_inferior_num = inferior_list->num;
 }
 
 struct inferior *
--- ../orig/gdb/infrun.c
+++ ./gdb/infrun.c
@@ -2584,7 +2584,7 @@ 
 	  /* Fallback to stepping over the breakpoint in-line.  */
 
 	  if (target_is_non_stop_p ())
-	    stop_all_threads ();
+	    stop_all_threads (tp->inf);
 
 	  set_step_over_info (get_regcache_aspace (regcache),
 			      regcache_read_pc (regcache), 0, tp->global_num);
@@ -4496,7 +4496,7 @@ 
 /* See infrun.h.  */
 
 void
-stop_all_threads (void)
+stop_all_threads (struct inferior *inferior)
 {
   /* We may need multiple passes to discover all threads.  */
   int pass;
@@ -4509,6 +4509,11 @@ 
   if (debug_infrun)
     fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
 
+  /* With global break points we have always to
+     stop all threads of all inferiors.  */
+  if (gdbarch_has_global_breakpoints (target_gdbarch ()))
+    inferior = NULL;
+
   entry_ptid = inferior_ptid;
   old_chain = make_cleanup (switch_to_thread_cleanup, &entry_ptid);
 
@@ -4539,6 +4544,8 @@ 
 	     to tell the target to stop.  */
 	  ALL_NON_EXITED_THREADS (t)
 	    {
+	      if (inferior != NULL && inferior != t->inf)
+	      	continue;
 	      if (t->executing)
 		{
 		  /* If already stopping, don't request a stop again.
@@ -5442,7 +5449,7 @@ 
 
   ALL_NON_EXITED_THREADS (tp)
     {
-      if (tp == event_thread)
+      if (tp == event_thread || tp->inf != event_thread->inf)
 	{
 	  if (debug_infrun)
 	    fprintf_unfiltered (gdb_stdlog,
@@ -7705,7 +7712,7 @@ 
   /* If all-stop, but the target is always in non-stop mode, stop all
      threads now that we're presenting the stop to the user.  */
   if (!non_stop && target_is_non_stop_p ())
-    stop_all_threads ();
+    stop_all_threads (NULL);
 }
 
 /* Like keep_going, but passes the signal to the inferior, even if the
@@ -7821,7 +7828,7 @@ 
 	 we're about to step over, otherwise other threads could miss
 	 it.  */
       if (step_over_info_valid_p () && target_is_non_stop_p ())
-	stop_all_threads ();
+	stop_all_threads (ecs->event_thread->inf);
 
       /* Stop stepping if inserting breakpoints fails.  */
       TRY
--- ../orig/gdb/infrun.h
+++ ./gdb/infrun.h
@@ -110,8 +110,12 @@ 
 extern void set_last_target_status (ptid_t ptid,
 				    struct target_waitstatus status);
 
-/* Stop all threads.  Only returns after everything is halted.  */
-extern void stop_all_threads (void);
+/* Stop all threads belonging to inf.
+   When called with inf == NULL, stop all threads of all inferiors.
+   With gdbarch_has_global_breakpoints () is true, always stop all
+   threads of all inferiors.
+   Only returns after everything is halted.  */
+extern void stop_all_threads (struct inferior *inf);
 
 extern void prepare_for_detach (void);
 
--- ../orig/gdb/remote.c
+++ ./gdb/remote.c
@@ -1789,8 +1789,24 @@ 
       /* In the traditional debugging scenario, there's a 1-1 match
 	 between program/address spaces.  We simply bind the inferior
 	 to the program space's address space.  */
-      inf = current_inferior ();
-      inferior_appeared (inf, pid);
+
+      inf = find_inferior_id (pid);
+      if (inf == NULL)
+        {
+	  if (current_inferior () ->pid == 0)
+	    {
+	      inf = current_inferior ();
+	      inferior_appeared (inf, pid);
+	    }
+	  else
+	    {
+	      inf = add_inferior (pid);
+	      inf->aspace = current_inferior () ->aspace;
+	      inf->pspace = current_program_space;
+	      inf->gdbarch = current_inferior () ->gdbarch;
+	      copy_inferior_target_desc_info(inf, current_inferior ());
+	    }
+        }
     }
 
   inf->attach_flag = attached;
@@ -1801,6 +1817,10 @@ 
   if (try_open_exec && get_exec_file (0) == NULL)
     exec_file_locate_attach (pid, 0, 1);
 
+  set_current_inferior (inf);
+
+  inferior_ptid = pid_to_ptid (pid);
+
   return inf;
 }
 
@@ -1902,6 +1922,9 @@ 
 
       /* This is really a new thread.  Add it.  */
       remote_add_thread (currthread, running, executing);
+      if (ptid_is_pid (inferior_ptid)
+	  && pid == ptid_get_pid (inferior_ptid))
+        inferior_ptid = currthread;
 
       /* If we found a new inferior, let the common code do whatever
 	 it needs to with it (e.g., read shared libraries, insert
@@ -3937,7 +3960,7 @@ 
      the inferiors.  */
   if (!non_stop)
     {
-      stop_all_threads ();
+      stop_all_threads (NULL);
 
       /* If all threads of an inferior were already stopped, we
 	 haven't setup the inferior yet.  */