2015-06-16  Luis Machado  <lgustavo@codesourcery.com>

	* breakpoint.c (make_breakpoint_permanent): Expand comment.
	Don't mark permanent locations as inserted.
	(add_location_to_breakpoint): Likewise
	(update_global_location_list): Don't error out if a permanent
	breakpoint is not marked inserted.
	Don't error out if a non-permanent breakpoint location is inserted on
	top of a permanent breakpoint.

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index eb3df02..768ce59 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -7440,15 +7440,16 @@ make_breakpoint_permanent (struct breakpoint *b)
   struct bp_location *bl;
 
   /* By definition, permanent breakpoints are already present in the
-     code.  Mark all locations as inserted.  For now,
-     make_breakpoint_permanent is called in just one place, so it's
-     hard to say if it's reasonable to have permanent breakpoint with
-     multiple locations or not, but it's easy to implement.  */
+     code.  For now, make_breakpoint_permanent is called in just one place, so
+     it's hard to say if it's reasonable to have permanent breakpoint with
+     multiple locations or not, but it's easy to implement.
+
+     Permanent breakpoints are not marked as inserted so we allow other
+     non-permanent locations at the same address to be inserted on top
+     of it.  This is required due to some targets, simulators mostly, not
+     dealing properly with hardwired breakpoints in the code.  */
   for (bl = b->loc; bl; bl = bl->next)
-    {
-      bl->permanent = 1;
-      bl->inserted = 1;
-    }
+    bl->permanent = 1;
 }
 
 /* Call this routine when stepping and nexting to enable a breakpoint
@@ -8918,11 +8919,10 @@ add_location_to_breakpoint (struct breakpoint *b,
   set_breakpoint_location_function (loc,
 				    sal->explicit_pc || sal->explicit_line);
 
+  /* See comment in make_breakpoint_permanent for the reason why we don't mark
+     permanent breakpoints as always inserted.  */
   if (bp_loc_is_permanent (loc))
-    {
-      loc->inserted = 1;
-      loc->permanent = 1;
-    }
+    loc->permanent = 1;
 
   return loc;
 }
@@ -12438,12 +12438,6 @@ update_global_location_list (enum ugll_insert_mode insert_mode)
 	  continue;
 	}
 
-      /* Permanent breakpoint should always be inserted.  */
-      if (loc->permanent && ! loc->inserted)
-	internal_error (__FILE__, __LINE__,
-			_("allegedly permanent breakpoint is not "
-			"actually inserted"));
-
       if (b->type == bp_hardware_watchpoint)
 	loc_first_p = &wp_loc_first;
       else if (b->type == bp_read_watchpoint)
@@ -12479,12 +12473,6 @@ update_global_location_list (enum ugll_insert_mode insert_mode)
 
       /* Clear the condition modification flag.  */
       loc->condition_changed = condition_unchanged;
-
-      if (loc->inserted && !loc->permanent
-	  && (*loc_first_p)->permanent)
-	internal_error (__FILE__, __LINE__,
-			_("another breakpoint was inserted on top of "
-			"a permanent breakpoint"));
     }
 
   if (insert_mode == UGLL_INSERT || breakpoints_should_be_inserted_now ())