[PATCH 1/3] Remove single-step breakpoint for GDBserver internal event

[Yao Qi <qiyaoltc at gmail dot com>]

This patch removes single-step breakpoints if the event is only
GDBserver internal, IOW, isn't reported back to GDB.

gdb/gdbserver:

2016-09-25  Yao Qi  <yao.qi@linaro.org>

	* linux-low.c (linux_wait_1): If single-step breakpoints are
	inserted, remove them.
---
 gdb/gdbserver/linux-low.c | 32 +++++++++++++++++++++++---------
 1 file changed, 23 insertions(+), 9 deletions(-)

diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index 4203b92..fd3cd5a 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -3670,17 +3670,31 @@ linux_wait_1 (ptid_t ptid,
 	  (*the_low_target.set_pc) (regcache, event_child->stop_pc);
 	}
 
-      /* We may have finished stepping over a breakpoint.  If so,
-	 we've stopped and suspended all LWPs momentarily except the
-	 stepping one.  This is where we resume them all again.  We're
-	 going to keep waiting, so use proceed, which handles stepping
-	 over the next breakpoint.  */
-      if (debug_threads)
-	debug_printf ("proceeding all threads.\n");
-
       if (step_over_finished)
-	unsuspend_all_lwps (event_child);
+	{
+	  /* If we have finished stepping over a breakpoint, we've
+	     stopped and suspended all LWPs momentarily except the
+	     stepping one.  This is where we resume them all again.
+	     We're going to keep waiting, so use proceed, which
+	     handles stepping over the next breakpoint.  */
+	  unsuspend_all_lwps (event_child);
+	}
+      else
+	{
+	  /* Remove the single-step breakpoints if any.  Note that
+	     there isn't single-step breakpoint if we finished stepping
+	     over.  */
+	  if (can_software_single_step ()
+	      && has_single_step_breakpoints (current_thread))
+	    {
+	      stop_all_lwps (0, event_child);
+	      delete_single_step_breakpoints (current_thread);
+	      unstop_all_lwps (0, event_child);
+	    }
+	}
 
+      if (debug_threads)
+	debug_printf ("proceeding all threads.\n");
       proceed_all_lwps ();
       return ignore_event (ourstatus);
     }
-- 
1.9.1