]> git.ipfire.org Git - thirdparty/binutils-gdb.git/blobdiff - gdb/infrun.c
Fix adjust_pc_after_break, remove still current thread check
[thirdparty/binutils-gdb.git] / gdb / infrun.c
index 29c37e1fefeb6acb4f2258237c29d8c5df32ffc6..15589b6a7660b1159a4043c630748b3b459208b7 100644 (file)
@@ -1,7 +1,7 @@
 /* Target-struct-independent code to start (run) and stop an inferior
    process.
 
-   Copyright (C) 1986-2014 Free Software Foundation, Inc.
+   Copyright (C) 1986-2015 Free Software Foundation, Inc.
 
    This file is part of GDB.
 
@@ -458,10 +458,11 @@ holding the child stopped.  Try \"set detach-on-fork\" or \
 
          if (info_verbose || debug_infrun)
            {
-             target_terminal_ours ();
+             target_terminal_ours_for_output ();
              fprintf_filtered (gdb_stdlog,
-                               "Detaching after fork from "
-                               "child process %d.\n",
+                               _("Detaching after %s from "
+                                 "child process %d.\n"),
+                               has_vforked ? "vfork" : "fork",
                                child_pid);
            }
        }
@@ -546,17 +547,13 @@ holding the child stopped.  Try \"set detach-on-fork\" or \
 
       if (info_verbose || debug_infrun)
        {
-         target_terminal_ours ();
-         if (has_vforked)
-           fprintf_filtered (gdb_stdlog,
-                             _("Attaching after process %d "
-                               "vfork to child process %d.\n"),
-                             parent_pid, child_pid);
-         else
-           fprintf_filtered (gdb_stdlog,
-                             _("Attaching after process %d "
-                               "fork to child process %d.\n"),
-                             parent_pid, child_pid);
+         target_terminal_ours_for_output ();
+         fprintf_filtered (gdb_stdlog,
+                           _("Attaching after process %d "
+                             "%s to child process %d.\n"),
+                           parent_pid,
+                           has_vforked ? "vfork" : "fork",
+                           child_pid);
        }
 
       /* Add the new inferior first, so that the target_detach below
@@ -593,7 +590,18 @@ holding the child stopped.  Try \"set detach-on-fork\" or \
          parent_inf->waiting_for_vfork_done = 0;
        }
       else if (detach_fork)
-       target_detach (NULL, 0);
+       {
+         if (info_verbose || debug_infrun)
+           {
+             target_terminal_ours_for_output ();
+             fprintf_filtered (gdb_stdlog,
+                               _("Detaching after fork from "
+                                 "child process %d.\n"),
+                               child_pid);
+           }
+
+         target_detach (NULL, 0);
+       }
 
       /* Note that the detach above makes PARENT_INF dangling.  */
 
@@ -927,18 +935,22 @@ handle_vfork_child_exec_or_exit (int exec)
 
          if (debug_infrun || info_verbose)
            {
-             target_terminal_ours ();
+             target_terminal_ours_for_output ();
 
              if (exec)
-               fprintf_filtered (gdb_stdlog,
-                                 "Detaching vfork parent process "
-                                 "%d after child exec.\n",
-                                 inf->vfork_parent->pid);
+               {
+                 fprintf_filtered (gdb_stdlog,
+                                   _("Detaching vfork parent process "
+                                     "%d after child exec.\n"),
+                                   inf->vfork_parent->pid);
+               }
              else
-               fprintf_filtered (gdb_stdlog,
-                                 "Detaching vfork parent process "
-                                 "%d after child exit.\n",
-                                 inf->vfork_parent->pid);
+               {
+                 fprintf_filtered (gdb_stdlog,
+                                   _("Detaching vfork parent process "
+                                     "%d after child exit.\n"),
+                                   inf->vfork_parent->pid);
+               }
            }
 
          target_detach (NULL, 0);
@@ -1082,6 +1094,7 @@ follow_exec (ptid_t pid, char *execd_pathname)
      statement through an exec().  */
   th->control.step_resume_breakpoint = NULL;
   th->control.exception_resume_breakpoint = NULL;
+  th->control.single_step_breakpoints = NULL;
   th->control.step_range_start = 0;
   th->control.step_range_end = 0;
 
@@ -1195,17 +1208,6 @@ follow_exec (ptid_t pid, char *execd_pathname)
      matically get reset there in the new process.).  */
 }
 
-/* Non-zero if we just simulating a single-step.  This is needed
-   because we cannot remove the breakpoints in the inferior process
-   until after the `wait' in `wait_for_inferior'.  */
-static int singlestep_breakpoints_inserted_p = 0;
-
-/* The thread we inserted single-step breakpoints for.  */
-static ptid_t singlestep_ptid;
-
-/* PC when we started this single-step.  */
-static CORE_ADDR singlestep_pc;
-
 /* Info about an instruction that is being stepped over.  */
 
 struct step_over_info
@@ -1782,6 +1784,10 @@ displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
   /* Did the instruction complete successfully?  */
   if (signal == GDB_SIGNAL_TRAP)
     {
+      /* Fixup may need to read memory/registers.  Switch to the
+        thread that we're fixing up.  */
+      switch_to_thread (event_ptid);
+
       /* Fix up the resulting state.  */
       gdbarch_displaced_step_fixup (displaced->step_gdbarch,
                                     displaced->step_closure,
@@ -1895,9 +1901,6 @@ infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
   if (ptid_equal (inferior_ptid, old_ptid))
     inferior_ptid = new_ptid;
 
-  if (ptid_equal (singlestep_ptid, old_ptid))
-    singlestep_ptid = new_ptid;
-
   for (displaced = displaced_step_inferior_states;
        displaced;
        displaced = displaced->next)
@@ -1918,8 +1921,8 @@ infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
 static void
 resume_cleanups (void *ignore)
 {
-  if (single_step_breakpoints_inserted ())
-    remove_single_step_breakpoints ();
+  if (!ptid_equal (inferior_ptid, null_ptid))
+    delete_single_step_breakpoints (inferior_thread ());
 
   normal_stop ();
 }
@@ -1975,11 +1978,6 @@ maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
       && gdbarch_software_single_step (gdbarch, get_current_frame ()))
     {
       hw_step = 0;
-      /* Do not pull these breakpoints until after a `wait' in
-        `wait_for_inferior'.  */
-      singlestep_breakpoints_inserted_p = 1;
-      singlestep_ptid = inferior_ptid;
-      singlestep_pc = pc;
     }
   return hw_step;
 }
@@ -2045,6 +2043,8 @@ resume (int step, enum gdb_signal sig)
      applies, it's the callers intention that counts.  */
   const int entry_step = step;
 
+  tp->stepped_breakpoint = 0;
+
   QUIT;
 
   if (current_inferior ()->waiting_for_vfork_done)
@@ -2081,13 +2081,81 @@ resume (int step, enum gdb_signal sig)
      breakpoints can't be removed.  So we have to test for it here.  */
   if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
     {
-      if (gdbarch_skip_permanent_breakpoint_p (gdbarch))
-       gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
+      if (sig != GDB_SIGNAL_0)
+       {
+         /* We have a signal to pass to the inferior.  The resume
+            may, or may not take us to the signal handler.  If this
+            is a step, we'll need to stop in the signal handler, if
+            there's one, (if the target supports stepping into
+            handlers), or in the next mainline instruction, if
+            there's no handler.  If this is a continue, we need to be
+            sure to run the handler with all breakpoints inserted.
+            In all cases, set a breakpoint at the current address
+            (where the handler returns to), and once that breakpoint
+            is hit, resume skipping the permanent breakpoint.  If
+            that breakpoint isn't hit, then we've stepped into the
+            signal handler (or hit some other event).  We'll delete
+            the step-resume breakpoint then.  */
+
+         if (debug_infrun)
+           fprintf_unfiltered (gdb_stdlog,
+                               "infrun: resume: skipping permanent breakpoint, "
+                               "deliver signal first\n");
+
+         clear_step_over_info ();
+         tp->control.trap_expected = 0;
+
+         if (tp->control.step_resume_breakpoint == NULL)
+           {
+             /* Set a "high-priority" step-resume, as we don't want
+                user breakpoints at PC to trigger (again) when this
+                hits.  */
+             insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
+             gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
+
+             tp->step_after_step_resume_breakpoint = step;
+           }
+
+         insert_breakpoints ();
+       }
       else
-       error (_("\
-The program is stopped at a permanent breakpoint, but GDB does not know\n\
-how to step past a permanent breakpoint on this architecture.  Try using\n\
-a command like `return' or `jump' to continue execution."));
+       {
+         /* There's no signal to pass, we can go ahead and skip the
+            permanent breakpoint manually.  */
+         if (debug_infrun)
+           fprintf_unfiltered (gdb_stdlog,
+                               "infrun: resume: skipping permanent breakpoint\n");
+         gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
+         /* Update pc to reflect the new address from which we will
+            execute instructions.  */
+         pc = regcache_read_pc (regcache);
+
+         if (step)
+           {
+             /* We've already advanced the PC, so the stepping part
+                is done.  Now we need to arrange for a trap to be
+                reported to handle_inferior_event.  Set a breakpoint
+                at the current PC, and run to it.  Don't update
+                prev_pc, because if we end in
+                switch_back_to_stepping, we want the "expected thread
+                advanced also" branch to be taken.  IOW, we don't
+                want this thread to step further from PC
+                (overstep).  */
+             insert_single_step_breakpoint (gdbarch, aspace, pc);
+             insert_breakpoints ();
+
+             tp->suspend.stop_signal = GDB_SIGNAL_0;
+             /* We're continuing with all breakpoints inserted.  It's
+                safe to let the target bypass signals.  */
+             target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
+             /* ... and safe to let other threads run, according to
+                schedlock.  */
+             resume_ptid = user_visible_resume_ptid (entry_step);
+             target_resume (resume_ptid, 0, GDB_SIGNAL_0);
+             discard_cleanups (old_cleanups);
+             return;
+           }
+       }
     }
 
   /* If we have a breakpoint to step over, make sure to do a single
@@ -2107,8 +2175,7 @@ a command like `return' or `jump' to continue execution."));
      event, displaced stepping breaks the vfork child similarly as single
      step software breakpoint.  */
   if (use_displaced_stepping (gdbarch)
-      && (tp->control.trap_expected
-         || (step && gdbarch_software_single_step_p (gdbarch)))
+      && tp->control.trap_expected
       && sig == GDB_SIGNAL_0
       && !current_inferior ()->waiting_for_vfork_done)
     {
@@ -2167,7 +2234,7 @@ a command like `return' or `jump' to continue execution."));
      at the current address, deliver the signal without stepping, and
      once we arrive back at the step-resume breakpoint, actually step
      over the breakpoint we originally wanted to step over.  */
-  if (singlestep_breakpoints_inserted_p
+  if (thread_has_single_step_breakpoints_set (tp)
       && sig != GDB_SIGNAL_0
       && step_over_info_valid_p ())
     {
@@ -2182,8 +2249,7 @@ a command like `return' or `jump' to continue execution."));
          tp->step_after_step_resume_breakpoint = 1;
        }
 
-      remove_single_step_breakpoints ();
-      singlestep_breakpoints_inserted_p = 0;
+      delete_single_step_breakpoints (tp);
 
       clear_step_over_info ();
       tp->control.trap_expected = 0;
@@ -2194,7 +2260,7 @@ a command like `return' or `jump' to continue execution."));
   /* If STEP is set, it's a request to use hardware stepping
      facilities.  But in that case, we should never
      use singlestep breakpoint.  */
-  gdb_assert (!(singlestep_breakpoints_inserted_p && step));
+  gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
 
   /* Decide the set of threads to ask the target to resume.  Start
      by assuming everything will be resumed, than narrow the set
@@ -2210,7 +2276,7 @@ a command like `return' or `jump' to continue execution."));
     set_running (resume_ptid, 1);
 
   /* Maybe resume a single thread after all.  */
-  if ((step || singlestep_breakpoints_inserted_p)
+  if ((step || thread_has_single_step_breakpoints_set (tp))
       && tp->control.trap_expected)
     {
       /* We're allowing a thread to run past a breakpoint it has
@@ -2221,12 +2287,35 @@ a command like `return' or `jump' to continue execution."));
       resume_ptid = inferior_ptid;
     }
 
-  if (gdbarch_cannot_step_breakpoint (gdbarch))
-    {
+  if (execution_direction != EXEC_REVERSE
+      && step && breakpoint_inserted_here_p (aspace, pc))
+    {
+      /* The only case we currently need to step a breakpoint
+        instruction is when we have a signal to deliver.  See
+        handle_signal_stop where we handle random signals that could
+        take out us out of the stepping range.  Normally, in that
+        case we end up continuing (instead of stepping) over the
+        signal handler with a breakpoint at PC, but there are cases
+        where we should _always_ single-step, even if we have a
+        step-resume breakpoint, like when a software watchpoint is
+        set.  Assuming single-stepping and delivering a signal at the
+        same time would takes us to the signal handler, then we could
+        have removed the breakpoint at PC to step over it.  However,
+        some hardware step targets (like e.g., Mac OS) can't step
+        into signal handlers, and for those, we need to leave the
+        breakpoint at PC inserted, as otherwise if the handler
+        recurses and executes PC again, it'll miss the breakpoint.
+        So we leave the breakpoint inserted anyway, but we need to
+        record that we tried to step a breakpoint instruction, so
+        that adjust_pc_after_break doesn't end up confused.  */
+      gdb_assert (sig != GDB_SIGNAL_0);
+
+      tp->stepped_breakpoint = 1;
+
       /* Most targets can step a breakpoint instruction, thus
         executing it normally.  But if this one cannot, just
         continue and we will hit it anyway.  */
-      if (step && breakpoint_inserted_here_p (aspace, pc))
+      if (gdbarch_cannot_step_breakpoint (gdbarch))
        step = 0;
     }
 
@@ -2373,7 +2462,8 @@ thread_still_needs_step_over (struct thread_info *tp)
       struct regcache *regcache = get_thread_regcache (tp->ptid);
 
       if (breakpoint_here_p (get_regcache_aspace (regcache),
-                            regcache_read_pc (regcache)))
+                            regcache_read_pc (regcache))
+         == ordinary_breakpoint_here)
        return 1;
 
       tp->stepping_over_breakpoint = 0;
@@ -2489,7 +2579,8 @@ proceed (CORE_ADDR addr, enum gdb_signal siggnal, int step)
 
   if (addr == (CORE_ADDR) -1)
     {
-      if (pc == stop_pc && breakpoint_here_p (aspace, pc)
+      if (pc == stop_pc
+         && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
          && execution_direction != EXEC_REVERSE)
        /* There is a breakpoint at the address we will resume at,
           step one instruction before inserting breakpoints so that
@@ -2679,26 +2770,9 @@ init_wait_for_inferior (void)
 
   /* Discard any skipped inlined frames.  */
   clear_inline_frame_state (minus_one_ptid);
-
-  singlestep_ptid = null_ptid;
-  singlestep_pc = 0;
 }
 
 \f
-/* This enum encodes possible reasons for doing a target_wait, so that
-   wfi can call target_wait in one place.  (Ultimately the call will be
-   moved out of the infinite loop entirely.) */
-
-enum infwait_states
-{
-  infwait_normal_state,
-  infwait_step_watch_state,
-  infwait_nonstep_watch_state
-};
-
-/* Current inferior wait state.  */
-static enum infwait_states infwait_state;
-
 /* Data to be passed around while handling an event.  This data is
    discarded between events.  */
 struct execution_control_state
@@ -2857,6 +2931,7 @@ delete_thread_infrun_breakpoints (struct thread_info *tp)
 {
   delete_step_resume_breakpoint (tp);
   delete_exception_resume_breakpoint (tp);
+  delete_single_step_breakpoints (tp);
 }
 
 /* If the target still has execution, call FUNC for each thread that
@@ -2896,9 +2971,15 @@ static void
 delete_just_stopped_threads_infrun_breakpoints (void)
 {
   for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
+}
 
-  if (single_step_breakpoints_inserted ())
-    remove_single_step_breakpoints ();
+/* Delete the single-step breakpoints of the threads that just
+   stopped.  */
+
+static void
+delete_just_stopped_threads_single_step_breakpoints (void)
+{
+  for_each_just_stopped_thread (delete_single_step_breakpoints);
 }
 
 /* A cleanup wrapper.  */
@@ -3088,6 +3169,33 @@ wait_for_inferior (void)
   do_cleanups (old_cleanups);
 }
 
+/* Cleanup that reinstalls the readline callback handler, if the
+   target is running in the background.  If while handling the target
+   event something triggered a secondary prompt, like e.g., a
+   pagination prompt, we'll have removed the callback handler (see
+   gdb_readline_wrapper_line).  Need to do this as we go back to the
+   event loop, ready to process further input.  Note this has no
+   effect if the handler hasn't actually been removed, because calling
+   rl_callback_handler_install resets the line buffer, thus losing
+   input.  */
+
+static void
+reinstall_readline_callback_handler_cleanup (void *arg)
+{
+  if (!interpreter_async)
+    {
+      /* We're not going back to the top level event loop yet.  Don't
+        install the readline callback, as it'd prep the terminal,
+        readline-style (raw, noecho) (e.g., --batch).  We'll install
+        it the next time the prompt is displayed, when we're ready
+        for input.  */
+      return;
+    }
+
+  if (async_command_editing_p && !sync_execution)
+    gdb_rl_callback_handler_reinstall ();
+}
+
 /* Asynchronous version of wait_for_inferior.  It is called by the
    event loop whenever a change of state is detected on the file
    descriptor corresponding to the target.  It can be called more than
@@ -3110,6 +3218,9 @@ fetch_inferior_event (void *client_data)
 
   memset (ecs, 0, sizeof (*ecs));
 
+  /* End up with readline processing input, if necessary.  */
+  make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
+
   /* We're handling a live event, so make sure we're doing live
      debugging.  If we're looking at traceframes while the target is
      running, we're going to need to get back to that mode after
@@ -3165,7 +3276,7 @@ fetch_inferior_event (void *client_data)
 
   if (!ecs->wait_some_more)
     {
-      struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
+      struct inferior *inf = find_inferior_ptid (ecs->ptid);
 
       delete_just_stopped_threads_infrun_breakpoints ();
 
@@ -3225,6 +3336,7 @@ set_step_info (struct frame_info *frame, struct symtab_and_line sal)
 void
 init_thread_stepping_state (struct thread_info *tss)
 {
+  tss->stepped_breakpoint = 0;
   tss->stepping_over_breakpoint = 0;
   tss->stepping_over_watchpoint = 0;
   tss->step_after_step_resume_breakpoint = 0;
@@ -3375,7 +3487,6 @@ adjust_pc_after_break (struct execution_control_state *ecs)
 
         The SIGTRAP can be due to a completed hardware single-step only if 
          - we didn't insert software single-step breakpoints
-         - the thread to be examined is still the current thread
          - this thread is currently being stepped
 
         If any of these events did not occur, we must have stopped due
@@ -3386,10 +3497,10 @@ adjust_pc_after_break (struct execution_control_state *ecs)
         software breakpoint.  In this case (prev_pc == breakpoint_pc),
         we also need to back up to the breakpoint address.  */
 
-      if (singlestep_breakpoints_inserted_p
-         || !ptid_equal (ecs->ptid, inferior_ptid)
+      if (thread_has_single_step_breakpoints_set (ecs->event_thread)
          || !currently_stepping (ecs->event_thread)
-         || ecs->event_thread->prev_pc == breakpoint_pc)
+         || (ecs->event_thread->stepped_breakpoint
+             && ecs->event_thread->prev_pc == breakpoint_pc))
        regcache_write_pc (regcache, breakpoint_pc);
 
       do_cleanups (old_cleanups);
@@ -3482,7 +3593,7 @@ fill_in_stop_func (struct gdbarch *gdbarch,
 static enum stop_kind
 get_inferior_stop_soon (ptid_t ptid)
 {
-  struct inferior *inf = find_inferior_pid (ptid_get_pid (ptid));
+  struct inferior *inf = find_inferior_ptid (ptid);
 
   gdb_assert (inf != NULL);
   return inf->control.stop_soon;
@@ -3716,7 +3827,7 @@ handle_inferior_event (struct execution_control_state *ecs)
        }
 
       inferior_ptid = ecs->ptid;
-      set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid)));
+      set_current_inferior (find_inferior_ptid (ecs->ptid));
       set_current_program_space (current_inferior ()->pspace);
       handle_vfork_child_exec_or_exit (0);
       target_terminal_ours (); /* Must do this before mourn anyway.  */
@@ -3772,8 +3883,6 @@ Cannot fill $_exitsignal with the correct signal number.\n"));
 
       gdb_flush (gdb_stdout);
       target_mourn_inferior ();
-      singlestep_breakpoints_inserted_p = 0;
-      cancel_single_step_breakpoints ();
       stop_print_frame = 0;
       stop_waiting (ecs);
       return;
@@ -3802,7 +3911,7 @@ Cannot fill $_exitsignal with the correct signal number.\n"));
        if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid))
          {
            struct inferior *parent_inf
-             = find_inferior_pid (ptid_get_pid (ecs->ptid));
+             = find_inferior_ptid (ecs->ptid);
            struct regcache *child_regcache;
            CORE_ADDR parent_pc;
 
@@ -3866,12 +3975,7 @@ Cannot fill $_exitsignal with the correct signal number.\n"));
          detach_breakpoints (ecs->ws.value.related_pid);
        }
 
-      if (singlestep_breakpoints_inserted_p)
-       {
-         /* Pull the single step breakpoints out of the target.  */
-         remove_single_step_breakpoints ();
-         singlestep_breakpoints_inserted_p = 0;
-       }
+      delete_just_stopped_threads_single_step_breakpoints ();
 
       /* In case the event is caught by a catchpoint, remember that
         the event is to be followed at the next resume of the thread,
@@ -3958,9 +4062,6 @@ Cannot fill $_exitsignal with the correct signal number.\n"));
       if (!ptid_equal (ecs->ptid, inferior_ptid))
        context_switch (ecs->ptid);
 
-      singlestep_breakpoints_inserted_p = 0;
-      cancel_single_step_breakpoints ();
-
       stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
 
       /* Do whatever is necessary to the parent branch of the vfork.  */
@@ -4026,14 +4127,7 @@ Cannot fill $_exitsignal with the correct signal number.\n"));
         fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
       /* Reverse execution: target ran out of history info.  */
 
-      /* Pull the single step breakpoints out of the target.  */
-      if (singlestep_breakpoints_inserted_p)
-       {
-         if (!ptid_equal (ecs->ptid, inferior_ptid))
-           context_switch (ecs->ptid);
-         remove_single_step_breakpoints ();
-         singlestep_breakpoints_inserted_p = 0;
-       }
+      delete_just_stopped_threads_single_step_breakpoints ();
       stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
       observer_notify_no_history ();
       stop_waiting (ecs);
@@ -4172,38 +4266,46 @@ handle_signal_stop (struct execution_control_state *ecs)
   gdbarch = get_frame_arch (frame);
 
   /* Pull the single step breakpoints out of the target.  */
-  if (singlestep_breakpoints_inserted_p)
+  if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
     {
+      struct regcache *regcache;
+      struct address_space *aspace;
+      CORE_ADDR pc;
+
+      regcache = get_thread_regcache (ecs->ptid);
+      aspace = get_regcache_aspace (regcache);
+      pc = regcache_read_pc (regcache);
+
       /* However, before doing so, if this single-step breakpoint was
         actually for another thread, set this thread up for moving
         past it.  */
-      if (!ptid_equal (ecs->ptid, singlestep_ptid)
-         && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
+      if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
+                                                  aspace, pc))
        {
-         struct regcache *regcache;
-         struct address_space *aspace;
-         CORE_ADDR pc;
-
-         regcache = get_thread_regcache (ecs->ptid);
-         aspace = get_regcache_aspace (regcache);
-         pc = regcache_read_pc (regcache);
          if (single_step_breakpoint_inserted_here_p (aspace, pc))
            {
              if (debug_infrun)
                {
                  fprintf_unfiltered (gdb_stdlog,
-                                     "infrun: [%s] hit step over single-step"
-                                     " breakpoint of [%s]\n",
-                                     target_pid_to_str (ecs->ptid),
-                                     target_pid_to_str (singlestep_ptid));
+                                     "infrun: [%s] hit another thread's "
+                                     "single-step breakpoint\n",
+                                     target_pid_to_str (ecs->ptid));
                }
              ecs->hit_singlestep_breakpoint = 1;
            }
        }
-
-      remove_single_step_breakpoints ();
-      singlestep_breakpoints_inserted_p = 0;
+      else
+       {
+         if (debug_infrun)
+           {
+             fprintf_unfiltered (gdb_stdlog,
+                                 "infrun: [%s] hit its "
+                                 "single-step breakpoint\n",
+                                 target_pid_to_str (ecs->ptid));
+           }
+       }
     }
+  delete_just_stopped_threads_single_step_breakpoints ();
 
   if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
       && ecs->event_thread->control.trap_expected
@@ -4405,7 +4507,7 @@ handle_signal_stop (struct execution_control_state *ecs)
   if (random_signal)
     {
       /* Signal not for debugging purposes.  */
-      struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
+      struct inferior *inf = find_inferior_ptid (ecs->ptid);
       enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
 
       if (debug_infrun)
@@ -4472,9 +4574,9 @@ handle_signal_stop (struct execution_control_state *ecs)
          return;
        }
 
-      if (ecs->event_thread->control.step_range_end != 0
-         && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
-         && pc_in_thread_step_range (stop_pc, ecs->event_thread)
+      if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
+         && (pc_in_thread_step_range (stop_pc, ecs->event_thread)
+             || ecs->event_thread->control.step_range_end == 1)
          && frame_id_eq (get_stack_frame_id (frame),
                          ecs->event_thread->control.step_stack_frame_id)
          && ecs->event_thread->control.step_resume_breakpoint == NULL)
@@ -4494,6 +4596,7 @@ handle_signal_stop (struct execution_control_state *ecs)
                                 "single-step range\n");
 
          insert_hp_step_resume_breakpoint_at_frame (frame);
+         ecs->event_thread->step_after_step_resume_breakpoint = 1;
          /* Reset trap_expected to ensure breakpoints are re-inserted.  */
          ecs->event_thread->control.trap_expected = 0;
          keep_going (ecs);
@@ -4756,6 +4859,30 @@ process_event_stop_test (struct execution_control_state *ecs)
       break;
     }
 
+  /* If we stepped a permanent breakpoint and we had a high priority
+     step-resume breakpoint for the address we stepped, but we didn't
+     hit it, then we must have stepped into the signal handler.  The
+     step-resume was only necessary to catch the case of _not_
+     stepping into the handler, so delete it, and fall through to
+     checking whether the step finished.  */
+  if (ecs->event_thread->stepped_breakpoint)
+    {
+      struct breakpoint *sr_bp
+       = ecs->event_thread->control.step_resume_breakpoint;
+
+      if (sr_bp->loc->permanent
+         && sr_bp->type == bp_hp_step_resume
+         && sr_bp->loc->address == ecs->event_thread->prev_pc)
+       {
+         if (debug_infrun)
+           fprintf_unfiltered (gdb_stdlog,
+                               "infrun: stepped permanent breakpoint, stopped in "
+                               "handler\n");
+         delete_step_resume_breakpoint (ecs->event_thread);
+         ecs->event_thread->step_after_step_resume_breakpoint = 0;
+       }
+    }
+
   /* We come here if we hit a breakpoint but should not stop for it.
      Possibly we also were stepping and should stop for that.  So fall
      through and test for stepping.  But, if not stepping, do not
@@ -4966,17 +5093,11 @@ process_event_stop_test (struct execution_control_state *ecs)
       if (debug_infrun)
         fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
 
-      if ((ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
-         || ((ecs->event_thread->control.step_range_end == 1)
-             && in_prologue (gdbarch, ecs->event_thread->prev_pc,
-                             ecs->stop_func_start)))
+      if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
        {
          /* I presume that step_over_calls is only 0 when we're
             supposed to be stepping at the assembly language level
             ("stepi").  Just stop.  */
-         /* Also, maybe we just did a "nexti" inside a prolog, so we
-            thought it was a subroutine call but it was not.  Stop as
-            well.  FENN */
          /* And this works the same backward as frontward.  MVS */
          end_stepping_range (ecs);
          return;
@@ -5424,7 +5545,7 @@ switch_back_to_stepped_thread (struct execution_control_state *ecs)
                 stepping, then scheduler locking can't be in effect,
                 otherwise we wouldn't have resumed the current event
                 thread in the first place.  */
-             gdb_assert (!schedlock_applies (1));
+             gdb_assert (!schedlock_applies (currently_stepping (tp)));
 
              stepping_thread = tp;
            }
@@ -5526,8 +5647,7 @@ switch_back_to_stepped_thread (struct execution_control_state *ecs)
             breakpoint forward, one instruction at a time,
             overstepping.  */
 
-         if (gdbarch_software_single_step_p (gdbarch)
-             && stop_pc != tp->prev_pc)
+         if (stop_pc != tp->prev_pc)
            {
              if (debug_infrun)
                fprintf_unfiltered (gdb_stdlog,
@@ -5544,10 +5664,7 @@ switch_back_to_stepped_thread (struct execution_control_state *ecs)
              insert_single_step_breakpoint (get_frame_arch (frame),
                                             get_frame_address_space (frame),
                                             stop_pc);
-             singlestep_breakpoints_inserted_p = 1;
              ecs->event_thread->control.trap_expected = 1;
-             singlestep_ptid = inferior_ptid;
-             singlestep_pc = stop_pc;
 
              resume (0, GDB_SIGNAL_0);
              prepare_to_wait (ecs);
@@ -5575,6 +5692,7 @@ currently_stepping (struct thread_info *tp)
   return ((tp->control.step_range_end
           && tp->control.step_resume_breakpoint == NULL)
          || tp->control.trap_expected
+         || tp->stepped_breakpoint
          || bpstat_should_step ());
 }
 
@@ -5586,13 +5704,13 @@ static void
 handle_step_into_function (struct gdbarch *gdbarch,
                           struct execution_control_state *ecs)
 {
-  struct symtab *s;
+  struct compunit_symtab *cust;
   struct symtab_and_line stop_func_sal, sr_sal;
 
   fill_in_stop_func (gdbarch, ecs);
 
-  s = find_pc_symtab (stop_pc);
-  if (s && s->language != language_asm)
+  cust = find_pc_compunit_symtab (stop_pc);
+  if (cust != NULL && compunit_language (cust) != language_asm)
     ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
                                                  ecs->stop_func_start);
 
@@ -5665,13 +5783,13 @@ static void
 handle_step_into_function_backward (struct gdbarch *gdbarch,
                                    struct execution_control_state *ecs)
 {
-  struct symtab *s;
+  struct compunit_symtab *cust;
   struct symtab_and_line stop_func_sal;
 
   fill_in_stop_func (gdbarch, ecs);
 
-  s = find_pc_symtab (stop_pc);
-  if (s && s->language != language_asm)
+  cust = find_pc_compunit_symtab (stop_pc);
+  if (cust != NULL && compunit_language (cust) != language_asm)
     ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
                                                  ecs->stop_func_start);