gdb: rename unwindonsignal to unwind-on-signal

We now have unwind-on-timeout and unwind-on-terminating-exception, and
then the odd one out unwindonsignal.

I'm not a great fan of these squashed together command names, so in
this commit I propose renaming this to unwind-on-signal.

Obviously I've added the hidden alias unwindonsignal so any existing
GDB scripts will keep working.

There's one test that I've extended to test the alias works, but in
most of the other test scripts I've changed over to use the new name.

The docs are updated to reference the new name.

gdb/NEWS

@@ -17,6 +17,44 @@ maintenance print record-instruction [ N ]
   prints how GDB would undo the N-th previous instruction, and if N is
   positive, it prints how GDB will redo the N-th following instruction.
 
+set direct-call-timeout SECONDS
+show direct-call-timeout
+set indirect-call-timeout SECONDS
+show indirect-call-timeout
+  These new settings can be used to limit how long GDB will wait for
+  an inferior function call to complete.  The direct timeout is used
+  for inferior function calls from e.g. 'call' and 'print' commands,
+  while the indirect timeout is used for inferior function calls from
+  within a conditional breakpoint expression.
+
+  The default for the direct timeout is unlimited, while the default
+  for the indirect timeout is 30 seconds.
+
+  These timeouts will only have an effect for targets that are
+  operating in async mode.  For non-async targets the timeouts are
+  ignored, GDB will wait indefinitely for an inferior function to
+  complete, unless interrupted by the user using Ctrl-C.
+
+set unwind-on-timeout on|off
+show unwind-on-timeout
+  These commands control whether GDB should unwind the stack when a
+  timeout occurs during an inferior function call.  The default is
+  off, in which case the inferior will remain in the frame where the
+  timeout occurred.  When on GDB will unwind the stack remocing the
+  dummy frame that was added for the inferior call, and restoring the
+  inferior state to how it was before the inferior call started.
+
+set unwind-on-signal on|off
+show unwind-on-signal
+  These new commands replaces the existing set/show unwindonsignal.  The
+  old command is maintained as an alias.
+
+* Changed commands
+
+set unwindonsignal on|off
+show unwindonsignal
+  These commands are now aliases for the new set/show unwind-on-signal.
+
 * MI changes
 
 ** mi now reports 'no-history' as a stop reason when hitting the end of the

gdb/breakpoint.c

@@ -5533,16 +5533,31 @@ bpstat_check_breakpoint_conditions (bpstat *bs, thread_info *thread)
 	  else
 	    within_current_scope = false;
 	}
+      CORE_ADDR pc_before_check = get_frame_pc (get_selected_frame (nullptr));
       if (within_current_scope)
 	{
 	  try
 	    {
+	      scoped_restore reset_in_cond_eval
+		= make_scoped_restore (&thread->control.in_cond_eval, true);
 	      condition_result = breakpoint_cond_eval (cond);
 	    }
 	  catch (const gdb_exception &ex)
 	    {
 	      exception_fprintf (gdb_stderr, ex,
-				 "Error in testing breakpoint condition:\n");
+				 "Error in testing condition for breakpoint %d:\n",
+				 b->number);
+
+	      /* If the pc value changed as a result of evaluating the
+		 condition then we probably stopped within an inferior
+		 function call due to some unexpected stop, e.g. the thread
+		 hit another breakpoint, or the thread received an
+		 unexpected signal.  In this case we don't want to also
+		 print the information about this breakpoint.  */
+	      CORE_ADDR pc_after_check
+		= get_frame_pc (get_selected_frame (nullptr));
+	      if (pc_before_check != pc_after_check)
+		bs->print = 0;
 	    }
 	}
       else

gdb/doc/gdb.texinfo

@@ -5713,6 +5713,17 @@ conditions for the
 purpose of performing side effects when a breakpoint is reached
 (@pxref{Break Commands, ,Breakpoint Command Lists}).
 
+If a breakpoint condition calls a function in your program, then it is
+possible that your program could stop for some reason while in the
+called function.  For example, @value{GDBN} might hit a breakpoint in
+the called function, or the called function may receive a signal
+(e.g.@ a @code{SIGSEGV}) as a result of some undefined behaviour, if
+this happens then @value{GDBN} will stop.  Depending on the settings
+@code{unwindonsignal}, @code{unwind-on-terminating-exception}, and
+@code{unwind-on-timeout} (@pxref{Calling,,Calling Program Functions})
+@value{GDBN} may unwind the stack back to the breakpoint location, or
+may leave the program at the frame where the stop occurred.
+
 Breakpoint conditions can also be evaluated on the target's side if
 the target supports it.  Instead of evaluating the conditions locally,
 @value{GDBN} encodes the expression into an agent expression
@@ -20696,7 +20707,7 @@ value history.
 It is possible for the function you call via the @code{print} or
 @code{call} command to generate a signal (e.g., if there's a bug in
 the function, or if you passed it incorrect arguments).  What happens
-in that case is controlled by the @code{set unwindonsignal} command.
+in that case is controlled by the @code{set unwind-on-signal} command.
 
 Similarly, with a C@t{++} program it is possible for the function you
 call via the @code{print} or @code{call} command to generate an
@@ -20709,7 +20720,8 @@ in that case is controlled by the
 @code{set unwind-on-terminating-exception} command.
 
 @table @code
-@item set unwindonsignal
+@item set unwind-on-signal
+@kindex set unwind-on-signal
 @kindex set unwindonsignal
 @cindex unwind stack in called functions
 @cindex call dummy stack unwinding
@@ -20720,11 +20732,18 @@ the context to what it was before the call.  If set to off (the
 default), @value{GDBN} stops in the frame where the signal was
 received.
 
-@item show unwindonsignal
+The command @code{set unwindonsignal} is an alias for this command,
+and is maintained for backward compatibility.
+
+@item show unwind-on-signal
+@kindex show unwind-on-signal
 @kindex show unwindonsignal
 Show the current setting of stack unwinding in the functions called by
 @value{GDBN}.
 
+The command @code{show unwindonsignal} is an alias for this command,
+and is maintained for backward compatibility.
+
 @item set unwind-on-terminating-exception
 @kindex set unwind-on-terminating-exception
 @cindex unwind stack in called functions with unhandled exceptions
@@ -20741,6 +20760,21 @@ the default C@t{++} exception handler and the inferior terminated.
 Show the current setting of stack unwinding in the functions called by
 @value{GDBN}.
 
+@item set unwind-on-timeout
+@kindex set unwind-on-timeout
+@cindex unwind stack in called functions when timing out
+@cindex call dummy stack unwinding on timeout.
+Set unwinding of the stack if a function called from @value{GDBN}
+times out.  If set to @code{off} (the default), @value{GDBN} stops in
+the frame where the timeout occurred.  If set to @code{on},
+@value{GDBN} unwinds the stack it created for the call and restores
+the context to what it was before the call.
+
+@item show unwind-on-timeout
+@kindex show unwind-on-timeout
+Show whether @value{GDBN} will unwind the stack if a function called
+from @value{GDBN} times out.
+
 @item set may-call-functions
 @kindex set may-call-functions
 @cindex disabling calling functions in the program
@@ -20765,6 +20799,102 @@ Show permission to call functions in the program.
 
 @end table
 
+When calling a function within a program, it is possible that the
+program could enter a state from which the called function may never
+return.  If this happens then it is possible to interrupt the function
+call by typing the interrupt character (often @kbd{Ctrl-c}).
+
+If a called function is interrupted for any reason, and the stack is
+not unwound (due to @code{set unwind-on-terminating-exception on},
+@code{set unwind-on-timeout}, or @code{set unwind-on-signal on}), then
+the dummy-frame, created by @value{GDBN} to facilitate the call to the
+program function, will be visible in the backtrace, for example frame
+@code{#3} in the following backtrace:
+
+@smallexample
+(@value{GDBP}) backtrace
+#0  0x00007ffff7b3d1e7 in nanosleep () from /lib64/libc.so.6
+#1  0x00007ffff7b3d11e in sleep () from /lib64/libc.so.6
+#2  0x000000000040113f in deadlock () at test.cc:13
+#3  <function called from gdb>
+#4  breakpt () at test.cc:20
+#5  0x0000000000401151 in main () at test.cc:25
+@end smallexample
+
+At this point it is possible to examine the state of the inferior just
+like any other stop.
+
+Depending on why the function was interrupted then it may be possible
+to resume the inferior (using commands like @code{continue},
+@code{step}, etc).  In this case, when the inferior finally returns to
+the dummy-frame, @value{GDBN} will once again halt the inferior.
+
+On targets that support asynchronous execution (@pxref{Background
+Execution}) @value{GDBN} can place a timeout on any functions called
+from @value{GDBN}.  If the timeout expires and the function call is
+still ongoing, then @value{GDBN} will interrupt the program.
+
+For targets that don't support asynchronous execution
+(@pxref{Background Execution}) then timeouts for functions called from
+@value{GDBN} are not supported, the timeout settings described below
+will be treated as @code{unlimited}, meaning @value{GDBN} will wait
+indefinitely for function call to complete, unless interrupted by the
+user using @kbd{Ctrl-C}.
+
+@table @code
+@item set direct-call-timeout @var{seconds}
+@kindex set direct-call-timeout
+@cindex timeout for called functions
+Set the timeout used when calling functions in the program to
+@var{seconds}, which should be an integer greater than zero, or the
+special value @code{unlimited}, which indicates no timeout should be
+used.  The default for this setting is @code{unlimited}.
+
+This setting is used when the user calls a function directly from the
+command prompt, for example with a @code{call} or @code{print}
+command.
+
+This setting only works for targets that support asynchronous
+execution (@pxref{Background Execution}), for any other target the
+setting is treated as @code{unlimited}.
+
+@item show direct-call-timeout
+@kindex show direct-call-timeout
+@cindex timeout for called functions
+Show the timeout used when calling functions in the program with a
+@code{call} or @code{print} command.
+@end table
+
+It is also possible to call functions within the program from the
+condition of a conditional breakpoint (@pxref{Conditions, ,Break
+Conditions}).  A different setting controls the timeout used for
+function calls made from a breakpoint condition.
+
+@table @code
+@item set indirect-call-timeout @var{seconds}
+@kindex set indirect-call-timeout
+@cindex timeout for called functions
+Set the timeout used when calling functions in the program from a
+breakpoint or watchpoint condition to @var{seconds}, which should be
+an integer greater than zero, or the special value @code{unlimited},
+which indicates no timeout should be used.  The default for this
+setting is @code{30} seconds.
+
+This setting only works for targets that support asynchronous
+execution (@pxref{Background Execution}), for any other target the
+setting is treated as @code{unlimited}.
+
+If a function called from a breakpoint or watchpoint condition times
+out, then @value{GDBN} will stop at the point where the timeout
+occurred.  The breakpoint condition evaluation will be abandoned.
+
+@item show indirect-call-timeout
+@kindex show indirect-call-timeout
+@cindex timeout for called functions
+Show the timeout used when calling functions in the program from a
+breakpoint or watchpoint condition.
+@end table
+
 @subsection Calling functions with no debug info
 
 @cindex no debug info functions

gdb/gdbthread.h

@@ -171,6 +171,9 @@ struct thread_control_state
      command.  This is used to decide whether "set scheduler-locking
      step" behaves like "on" or "off".  */
   int stepping_command = 0;
+
+  /* True if the thread is evaluating a BP condition.  */
+  bool in_cond_eval = false;
 };
 
 /* Inferior thread specific part of `struct infcall_suspend_state'.  */

gdb/infcall.c

@@ -95,6 +95,53 @@ show_may_call_functions_p (struct ui_file *file, int from_tty,
 	      value);
 }
 
+/* A timeout (in seconds) for direct inferior calls.  A direct inferior
+   call is one the user triggers from the prompt, e.g. with a 'call' or
+   'print' command.  Compare with the definition of indirect calls below.  */
+
+static unsigned int direct_call_timeout = UINT_MAX;
+
+/* Implement 'show direct-call-timeout'.  */
+
+static void
+show_direct_call_timeout (struct ui_file *file, int from_tty,
+			  struct cmd_list_element *c, const char *value)
+{
+  if (target_has_execution () && !target_can_async_p ())
+    gdb_printf (file, _("Current target does not support async mode, timeout "
+			"for direct inferior calls is \"unlimited\".\n"));
+  else if (direct_call_timeout == UINT_MAX)
+    gdb_printf (file, _("Timeout for direct inferior function calls "
+			"is \"unlimited\".\n"));
+  else
+    gdb_printf (file, _("Timeout for direct inferior function calls "
+			"is \"%s seconds\".\n"), value);
+}
+
+/* A timeout (in seconds) for indirect inferior calls.  An indirect inferior
+   call is one that originates from within GDB, for example, when
+   evaluating an expression for a conditional breakpoint.  Compare with
+   the definition of direct calls above.  */
+
+static unsigned int indirect_call_timeout = 30;
+
+/* Implement 'show indirect-call-timeout'.  */
+
+static void
+show_indirect_call_timeout (struct ui_file *file, int from_tty,
+			  struct cmd_list_element *c, const char *value)
+{
+  if (target_has_execution () && !target_can_async_p ())
+    gdb_printf (file, _("Current target does not support async mode, timeout "
+			"for indirect inferior calls is \"unlimited\".\n"));
+  else if (indirect_call_timeout == UINT_MAX)
+    gdb_printf (file, _("Timeout for indirect inferior function calls "
+			"is \"unlimited\".\n"));
+  else
+    gdb_printf (file, _("Timeout for indirect inferior function calls "
+			"is \"%s seconds\".\n"), value);
+}
+
 /* How you should pass arguments to a function depends on whether it
    was defined in K&R style or prototype style.  If you define a
    function using the K&R syntax that takes a `float' argument, then
@@ -170,6 +217,27 @@ show_unwind_on_terminating_exception_p (struct ui_file *file, int from_tty,
 	      value);
 }
 
+/* This boolean tells what gdb should do if a signal is received while
+   in a function called from gdb (call dummy).  If set, gdb unwinds
+   the stack and restore the context to what as it was before the
+   call.
+
+   The default is to stop in the frame where the signal was received.  */
+
+static bool unwind_on_timeout_p = false;
+
+/* Implement 'show unwind-on-timeout'.  */
+
+static void
+show_unwind_on_timeout_p (struct ui_file *file, int from_tty,
+			  struct cmd_list_element *c, const char *value)
+{
+  gdb_printf (file,
+	      _("Unwinding of stack if a timeout occurs "
+		"while in a call dummy is %s.\n"),
+	      value);
+}
+
 /* Perform the standard coercions that are specified
    for arguments to be passed to C, Ada or Fortran functions.
 
@@ -589,6 +657,85 @@ call_thread_fsm::should_notify_stop ()
   return true;
 }
 
+/* A class to control creation of a timer that will interrupt a thread
+   during an inferior call.  */
+struct infcall_timer_controller
+{
+  /* Setup an event-loop timer that will interrupt PTID if the inferior
+     call takes too long.  DIRECT_CALL_P is true when this inferior call is
+     a result of the user using a 'print' or 'call' command, and false when
+     this inferior call is a result of e.g. a conditional breakpoint
+     expression, this is used to select which timeout to use.  */
+  infcall_timer_controller (ptid_t ptid, bool direct_call_p)
+    : m_ptid (ptid)
+  {
+    unsigned int timeout
+      = direct_call_p ? direct_call_timeout : indirect_call_timeout;
+    if (timeout < UINT_MAX && target_can_async_p ())
+      {
+	int ms = timeout * 1000;
+	int id = create_timer (ms, infcall_timer_controller::timed_out, this);
+	m_timer_id.emplace (id);
+	infcall_debug_printf ("Setting up infcall timeout timer for "
+			      "ptid %s: %d milliseconds",
+			      m_ptid.to_string ().c_str (), ms);
+      }
+  }
+
+  /* Destructor.  Ensure that the timer is removed from the event loop.  */
+  ~infcall_timer_controller ()
+  {
+    /* If the timer has already triggered, then it will have already been
+       deleted from the event loop.  If the timer has not triggered, then
+       delete it now.  */
+    if (m_timer_id.has_value () && !m_triggered)
+      delete_timer (*m_timer_id);
+
+    /* Just for clarity, discard the timer id now.  */
+    m_timer_id.reset ();
+  }
+
+  /* Return true if there was a timer in place, and the timer triggered,
+     otherwise, return false.  */
+  bool triggered_p ()
+  {
+    gdb_assert (!m_triggered || m_timer_id.has_value ());
+    return m_triggered;
+  }
+
+private:
+  /* The thread we should interrupt.  */
+  ptid_t m_ptid;
+
+  /* Set true when the timer is triggered.  */
+  bool m_triggered = false;
+
+  /* Given a value when a timer is in place.  */
+  gdb::optional<int> m_timer_id;
+
+  /* Callback for the timer, forwards to ::trigger below.  */
+  static void
+  timed_out (gdb_client_data context)
+  {
+    infcall_timer_controller *ctrl
+      = static_cast<infcall_timer_controller *> (context);
+    ctrl->trigger ();
+  }
+
+  /* Called when the timer goes off.  Stop thread m_ptid.  */
+  void
+  trigger ()
+  {
+    m_triggered = true;
+
+    scoped_disable_commit_resumed disable_commit_resumed ("infcall timeout");
+
+    infcall_debug_printf ("Stopping thread %s",
+			  m_ptid.to_string ().c_str ());
+    target_stop (m_ptid);
+  }
+};
+
 /* Subroutine of call_function_by_hand to simplify it.
    Start up the inferior and wait for it to stop.
    Return the exception if there's an error, or an exception with
@@ -599,13 +746,15 @@ call_thread_fsm::should_notify_stop ()
 
 static struct gdb_exception
 run_inferior_call (std::unique_ptr<call_thread_fsm> sm,
-		   struct thread_info *call_thread, CORE_ADDR real_pc)
+		   struct thread_info *call_thread, CORE_ADDR real_pc,
+		   bool *timed_out_p)
 {
   INFCALL_SCOPED_DEBUG_ENTER_EXIT;
 
   struct gdb_exception caught_error;
   ptid_t call_thread_ptid = call_thread->ptid;
   int was_running = call_thread->state == THREAD_RUNNING;
+  *timed_out_p = false;
 
   infcall_debug_printf ("call function at %s in thread %s, was_running = %d",
 			core_addr_to_string (real_pc),
@@ -641,14 +790,32 @@ run_inferior_call (std::unique_ptr<call_thread_fsm> sm,
 
       proceed (real_pc, GDB_SIGNAL_0);
 
+      /* Enable commit resume, but pass true for the force flag.  This
+	 ensures any thread we set running in proceed will actually be
+	 committed to the target, even if some other thread in the current
+	 target has a pending event.  */
+      scoped_enable_commit_resumed enable ("infcall", true);
+
       infrun_debug_show_threads ("non-exited threads after proceed for inferior-call",
 				 all_non_exited_threads ());
 
+      /* Setup a timer (if possible, and if the settings allow) to prevent
+	 the inferior call running forever.  */
+      bool direct_call_p = !call_thread->control.in_cond_eval;
+      infcall_timer_controller infcall_timer (inferior_ptid, direct_call_p);
+
       /* Inferior function calls are always synchronous, even if the
 	 target supports asynchronous execution.  */
       wait_sync_command_done ();
 
-      infcall_debug_printf ("inferior call completed successfully");
+      /* If the timer triggered then the inferior call failed.  */
+      if (infcall_timer.triggered_p ())
+	{
+	  infcall_debug_printf ("inferior call timed out");
+	  *timed_out_p = true;
+	}
+      else
+	infcall_debug_printf ("inferior call completed successfully");
     }
   catch (gdb_exception &e)
     {
@@ -1293,6 +1460,19 @@ call_function_by_hand_dummy (struct value *function,
   /* Register a clean-up for unwind_on_terminating_exception_breakpoint.  */
   SCOPE_EXIT { delete_std_terminate_breakpoint (); };
 
+  /* The stopped_by_random_signal variable is global.  If we are here
+     as part of a breakpoint condition check then the global will have
+     already been setup as part of the original breakpoint stop.  By
+     making the inferior call the global will be changed when GDB
+     handles the stop after the inferior call.  Avoid confusion by
+     restoring the current value after the inferior call.  */
+  scoped_restore restore_stopped_by_random_signal
+    = make_scoped_restore (&stopped_by_random_signal, 0);
+
+  /* Set to true by the call to run_inferior_call below if the inferior
+     call is artificially interrupted by GDB due to taking too long.  */
+  bool timed_out_p = false;
+
   /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP -
      If you're looking to implement asynchronous dummy-frames, then
      just below is the place to chop this function in two..  */
@@ -1319,7 +1499,8 @@ call_function_by_hand_dummy (struct value *function,
 			      struct_addr);
     {
       std::unique_ptr<call_thread_fsm> sm_up (sm);
-      e = run_inferior_call (std::move (sm_up), call_thread.get (), real_pc);
+      e = run_inferior_call (std::move (sm_up), call_thread.get (), real_pc,
+			     &timed_out_p);
     }
 
     if (e.reason < 0)
@@ -1471,7 +1652,10 @@ When the function is done executing, GDB will silently stop."),
       std::string name = get_function_name (funaddr, name_buf,
 					    sizeof (name_buf));
 
-      if (stopped_by_random_signal)
+      /* If the inferior call timed out then it will have been interrupted
+	 by a signal, but we want to report this differently to the user,
+	 which is done later in this function.  */
+      if (stopped_by_random_signal && !timed_out_p)
 	{
 	  /* We stopped inside the FUNCTION because of a random
 	     signal.  Further execution of the FUNCTION is not
@@ -1494,7 +1678,7 @@ When the function is done executing, GDB will silently stop."),
 	      error (_("\
 The program being debugged was signaled while in a function called from GDB.\n\
 GDB has restored the context to what it was before the call.\n\
-To change this behavior use \"set unwindonsignal off\".\n\
+To change this behavior use \"set unwind-on-signal off\".\n\
 Evaluation of the expression containing the function\n\
 (%s) will be abandoned."),
 		     name.c_str ());
@@ -1512,7 +1696,50 @@ Evaluation of the expression containing the function\n\
 	      error (_("\
 The program being debugged was signaled while in a function called from GDB.\n\
 GDB remains in the frame where the signal was received.\n\
-To change this behavior use \"set unwindonsignal on\".\n\
+To change this behavior use \"set unwind-on-signal on\".\n\
+Evaluation of the expression containing the function\n\
+(%s) will be abandoned.\n\
+When the function is done executing, GDB will silently stop."),
+		     name.c_str ());
+	    }
+	}
+
+      if (timed_out_p)
+	{
+	  /* A timeout results in a signal being sent to the inferior.  */
+	  gdb_assert (stopped_by_random_signal);
+
+	  if (unwind_on_timeout_p)
+	    {
+	      /* The user wants the context restored.  */
+
+	      /* We must get back to the frame we were before the
+		 dummy call.  */
+	      dummy_frame_pop (dummy_id, call_thread.get ());
+
+	      /* We also need to restore inferior status to that before the
+		 dummy call.  */
+	      restore_infcall_control_state (inf_status.release ());
+
+	      error (_("\
+The program being debugged timed out while in a function called from GDB.\n\
+GDB has restored the context to what it was before the call.\n\
+To change this behavior use \"set unwind-on-timeout off\".\n\
+Evaluation of the expression containing the function\n\
+(%s) will be abandoned."),
+		     name.c_str ());
+	    }
+	  else
+	    {
+	      /* The user wants to stay in the frame where we stopped
+		 (default).  Discard inferior status, we're not at the same
+		 point we started at.  */
+	      discard_infcall_control_state (inf_status.release ());
+
+	      error (_("\
+The program being debugged timed out while in a function called from GDB.\n\
+GDB remains in the frame where the timeout occurred.\n\
+To change this behavior use \"set unwind-on-timeout on\".\n\
 Evaluation of the expression containing the function\n\
 (%s) will be abandoned.\n\
 When the function is done executing, GDB will silently stop."),
@@ -1601,17 +1828,22 @@ The default is to perform the conversion."),
 			   show_coerce_float_to_double_p,
 			   &setlist, &showlist);
 
-  add_setshow_boolean_cmd ("unwindonsignal", no_class,
-			   &unwind_on_signal_p, _("\
+  set_show_commands setshow_unwind_on_signal_cmds
+    = add_setshow_boolean_cmd ("unwind-on-signal", no_class,
+			       &unwind_on_signal_p, _("\
 Set unwinding of stack if a signal is received while in a call dummy."), _("\
 Show unwinding of stack if a signal is received while in a call dummy."), _("\
-The unwindonsignal lets the user determine what gdb should do if a signal\n\
+The unwind-on-signal lets the user determine what gdb should do if a signal\n\
 is received while in a function called from gdb (call dummy).  If set, gdb\n\
 unwinds the stack and restore the context to what as it was before the call.\n\
 The default is to stop in the frame where the signal was received."),
-			   NULL,
-			   show_unwind_on_signal_p,
-			   &setlist, &showlist);
+			       NULL,
+			       show_unwind_on_signal_p,
+			       &setlist, &showlist);
+  add_alias_cmd ("unwindonsignal", setshow_unwind_on_signal_cmds.set,
+		 no_class, 1, &setlist);
+  add_alias_cmd ("unwindonsignal", setshow_unwind_on_signal_cmds.show,
+		 no_class, 1, &showlist);
 
   add_setshow_boolean_cmd ("unwind-on-terminating-exception", no_class,
 			   &unwind_on_terminating_exception_p, _("\
@@ -1628,6 +1860,44 @@ The default is to unwind the frame."),
 			   show_unwind_on_terminating_exception_p,
 			   &setlist, &showlist);
 
+  add_setshow_boolean_cmd ("unwind-on-timeout", no_class,
+			   &unwind_on_timeout_p, _("\
+Set unwinding of stack if a timeout occurs while in a call dummy."), _("\
+Show unwinding of stack if a timeout occurs while in a call dummy."),
+			   _("\
+The unwind on timeout flag lets the user determine what gdb should do if\n\
+gdb times out while in a function called from gdb.  If set, gdb unwinds\n\
+the stack and restores the context to what it was before the call.  If\n\
+unset, gdb leaves the inferior in the frame where the timeout occurred.\n\
+The default is to stop in the frame where the timeout occurred."),
+			   NULL,
+			   show_unwind_on_timeout_p,
+			   &setlist, &showlist);
+
+  add_setshow_uinteger_cmd ("direct-call-timeout", no_class,
+			    &direct_call_timeout, _("\
+Set the timeout, for direct calls to inferior function calls."), _("\
+Show the timeout, for direct calls to inferior function calls."), _("\
+If running on a target that supports, and is running in, async mode\n\
+then this timeout is used for any inferior function calls triggered\n\
+directly from the prompt, i.e. from a 'call' or 'print' command.  The\n\
+timeout is specified in seconds."),
+			    nullptr,
+			    show_direct_call_timeout,
+			    &setlist, &showlist);
+
+  add_setshow_uinteger_cmd ("indirect-call-timeout", no_class,
+			    &indirect_call_timeout, _("\
+Set the timeout, for indirect calls to inferior function calls."), _("\
+Show the timeout, for indirect calls to inferior function calls."), _("\
+If running on a target that supports, and is running in, async mode\n\
+then this timeout is used for any inferior function calls triggered\n\
+indirectly, i.e. being made as part of a breakpoint, or watchpoint,\n\
+condition expression.  The timeout is specified in seconds."),
+			    nullptr,
+			    show_indirect_call_timeout,
+			    &setlist, &showlist);
+
   add_setshow_boolean_cmd
     ("infcall", class_maintenance, &debug_infcall,
      _("Set inferior call debugging."),

gdb/infrun.c

@@ -2149,6 +2149,14 @@ user_visible_resume_ptid (int step)
 	 mode.  */
       resume_ptid = inferior_ptid;
     }
+  else if (inferior_ptid != null_ptid
+	   && inferior_thread ()->control.in_cond_eval)
+    {
+      /* The inferior thread is evaluating a BP condition.  Other threads
+	 might be stopped or running and we do not want to change their
+	 state, thus, resume only the current thread.  */
+      resume_ptid = inferior_ptid;
+    }
   else if (!sched_multi && target_supports_multi_process ())
     {
       /* Resume all threads of the current process (and none of other
@@ -2861,7 +2869,7 @@ schedlock_applies (struct thread_info *tp)
    pending events.  */
 
 static void
-maybe_set_commit_resumed_all_targets ()
+maybe_set_commit_resumed_all_targets (bool force_p)
 {
   scoped_restore_current_thread restore_thread;
 
@@ -2890,7 +2898,7 @@ maybe_set_commit_resumed_all_targets ()
 	 status to report, handle it before requiring the target to
 	 commit its resumed threads: handling the status might lead to
 	 resuming more threads.  */
-      if (proc_target->has_resumed_with_pending_wait_status ())
+      if (!force_p && proc_target->has_resumed_with_pending_wait_status ())
 	{
 	  infrun_debug_printf ("not requesting commit-resumed for target %s, a"
 			       " thread has a pending waitstatus",
@@ -2900,7 +2908,7 @@ maybe_set_commit_resumed_all_targets ()
 
       switch_to_inferior_no_thread (inf);
 
-      if (target_has_pending_events ())
+      if (!force_p && target_has_pending_events ())
 	{
 	  infrun_debug_printf ("not requesting commit-resumed for target %s, "
 			       "target has pending events",
@@ -2993,7 +3001,7 @@ scoped_disable_commit_resumed::reset ()
     {
       /* This is the outermost instance, re-enable
          COMMIT_RESUMED_STATE on the targets where it's possible.  */
-      maybe_set_commit_resumed_all_targets ();
+      maybe_set_commit_resumed_all_targets (false);
     }
   else
     {
@@ -3026,7 +3034,7 @@ scoped_disable_commit_resumed::reset_and_commit ()
 /* See infrun.h.  */
 
 scoped_enable_commit_resumed::scoped_enable_commit_resumed
-  (const char *reason)
+  (const char *reason, bool force_p)
   : m_reason (reason),
     m_prev_enable_commit_resumed (enable_commit_resumed)
 {
@@ -3038,7 +3046,7 @@ scoped_enable_commit_resumed::scoped_enable_commit_resumed
 
       /* Re-enable COMMIT_RESUMED_STATE on the targets where it's
 	 possible.  */
-      maybe_set_commit_resumed_all_targets ();
+      maybe_set_commit_resumed_all_targets (force_p);
 
       maybe_call_commit_resumed_all_targets ();
     }
@@ -3741,7 +3749,8 @@ do_target_wait_1 (inferior *inf, ptid_t ptid,
    more events.  Polls for events from all inferiors/targets.  */
 
 static bool
-do_target_wait (execution_control_state *ecs, target_wait_flags options)
+do_target_wait (ptid_t wait_ptid, execution_control_state *ecs,
+		target_wait_flags options)
 {
   int num_inferiors = 0;
   int random_selector;
@@ -3751,9 +3760,11 @@ do_target_wait (execution_control_state *ecs, target_wait_flags options)
      polling the rest of the inferior list starting from that one in a
      circular fashion until the whole list is polled once.  */
 
-  auto inferior_matches = [] (inferior *inf)
+  ptid_t wait_ptid_pid {wait_ptid.pid ()};
+  auto inferior_matches = [&wait_ptid_pid] (inferior *inf)
     {
-      return inf->process_target () != nullptr;
+      return (inf->process_target () != NULL
+	      && ptid_t (inf->pid).matches (wait_ptid_pid));
     };
 
   /* First see how many matching inferiors we have.  */
@@ -3792,7 +3803,7 @@ do_target_wait (execution_control_state *ecs, target_wait_flags options)
 
   auto do_wait = [&] (inferior *inf)
   {
-    ecs->ptid = do_target_wait_1 (inf, minus_one_ptid, &ecs->ws, options);
+    ecs->ptid = do_target_wait_1 (inf, wait_ptid, &ecs->ws, options);
     ecs->target = inf->process_target ();
     return (ecs->ws.kind () != TARGET_WAITKIND_IGNORE);
   };
@@ -4169,7 +4180,17 @@ fetch_inferior_event ()
        the event.  */
     scoped_disable_commit_resumed disable_commit_resumed ("handling event");
 
-    if (!do_target_wait (&ecs, TARGET_WNOHANG))
+    /* Is the current thread performing an inferior function call as part
+       of a breakpoint condition evaluation?  */
+    bool in_cond_eval = (inferior_ptid != null_ptid
+			 && inferior_thread ()->control.in_cond_eval);
+
+    /* If the thread is in the middle of the condition evaluation, wait for
+       an event from the current thread, otherwise, wait for an event from
+       any thread.  */
+    ptid_t waiton_ptid = in_cond_eval ? inferior_ptid : minus_one_ptid;
+
+    if (!do_target_wait (waiton_ptid, &ecs, TARGET_WNOHANG))
       {
 	infrun_debug_printf ("do_target_wait returned no event");
 	disable_commit_resumed.reset_and_commit ();
@@ -4221,7 +4242,12 @@ fetch_inferior_event ()
 	    bool should_notify_stop = true;
 	    bool proceeded = false;
 
-	    stop_all_threads_if_all_stop_mode ();
+	    /* If the thread that stopped just completed an inferior
+	       function call as part of a condition evaluation, then we
+	       don't want to stop all the other threads.  */
+	    if (ecs.event_thread == nullptr
+		|| !ecs.event_thread->control.in_cond_eval)
+	      stop_all_threads_if_all_stop_mode ();
 
 	    clean_up_just_stopped_threads_fsms (&ecs);
 
@@ -4236,7 +4262,7 @@ fetch_inferior_event ()
 		  proceeded = normal_stop ();
 	      }
 
-	    if (!proceeded)
+	    if (!proceeded && !in_cond_eval)
 	      {
 		inferior_event_handler (INF_EXEC_COMPLETE);
 		cmd_done = 1;

gdb/infrun.h

@@ -395,7 +395,7 @@ extern void maybe_call_commit_resumed_all_targets ();
 
 struct scoped_enable_commit_resumed
 {
-  explicit scoped_enable_commit_resumed (const char *reason);
+  explicit scoped_enable_commit_resumed (const char *reason, bool force_p = false);
   ~scoped_enable_commit_resumed ();
 
   DISABLE_COPY_AND_ASSIGN (scoped_enable_commit_resumed);

gdb/remote.c

@@ -1138,6 +1138,10 @@ struct remote_thread_info : public private_thread_info
   std::string name;
   int core = -1;
 
+  /* Only used when not in non-stop mode.  Set to true when a stop is
+     requested for the thread.  */
+  bool stop_requested = false;
+
   /* Thread handle, perhaps a pthread_t or thread_t value, stored as a
      sequence of bytes.  */
   gdb::byte_vector thread_handle;
@@ -7113,6 +7117,12 @@ remote_target::stop (ptid_t ptid)
       /* We don't currently have a way to transparently pause the
 	 remote target in all-stop mode.  Interrupt it instead.  */
       remote_interrupt_as ();
+
+      /* Record that this thread's stop is a result of GDB asking for the
+	 stop, rather than the user asking for an interrupt.  We can use
+	 this information to adjust the waitstatus when it arrives.  */
+      remote_thread_info *remote_thr = get_remote_thread_info (this, ptid);
+      remote_thr->stop_requested = true;
     }
 }
 
@@ -8096,9 +8106,16 @@ remote_target::process_stop_reply (struct stop_reply *stop_reply,
 	  /* If the target works in non-stop mode, a stop-reply indicates that
 	     only this thread stopped.  */
 	  remote_thr->set_not_resumed ();
+	  gdb_assert (!remote_thr->stop_requested);
 	}
       else
 	{
+	  if (status->kind () == TARGET_WAITKIND_STOPPED
+	      && status->sig () == GDB_SIGNAL_INT
+	      && remote_thr->stop_requested)
+	    status->set_stopped (GDB_SIGNAL_0);
+	  remote_thr->stop_requested = false;
+
 	  /* If the target works in all-stop mode, a stop-reply indicates that
 	     all the target's threads stopped.  */
 	  for (thread_info *tp : all_non_exited_threads (this))

gdb/testsuite/gdb.base/bp-cond-failure.c

@@ -0,0 +1,30 @@
+/* Copyright 2022 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+int
+foo ()
+{
+  return 0;	/* Breakpoint here.  */
+}
+
+int
+main ()
+{
+  int res = foo ();
+
+  return res;
+}

gdb/testsuite/gdb.base/bp-cond-failure.exp

@@ -0,0 +1,81 @@
+# Copyright 2022 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Check the format of the error message given when a breakpoint
+# condition fails.
+#
+# In this case the breakpoint condition does not make use of inferior
+# function calls, instead, the expression used for the breakpoint
+# condition will throw an error when evaluated.
+#
+# We check that the correct breakpoint number appears in the error
+# message, and that the error is reported at the correct source
+# location.
+
+standard_testfile
+
+if { [prepare_for_testing "failed to prepare" ${binfile} "${srcfile}" \
+	  {debug}] == -1 } {
+    return
+}
+
+# This test relies on reading address zero triggering a SIGSEGV.
+if { [is_address_zero_readable] } {
+    return
+}
+
+# Where the breakpoint will be placed.
+set bp_line [gdb_get_line_number "Breakpoint here"]
+
+proc run_test { cond_eval access_type } {
+    clean_restart ${::binfile}
+
+    if {![runto_main]} {
+	fail "run to main"
+	return -1
+    }
+
+    if { $cond_eval != "auto" } {
+	gdb_test_no_output "set breakpoint condition-evaluation ${cond_eval}"
+    }
+
+    # Setup the conditional breakpoint and record its number.
+    gdb_breakpoint "${::srcfile}:${::bp_line} if (*(${access_type} *) 0) == 0"
+    set bp_num [get_integer_valueof "\$bpnum" "*UNKNOWN*"]
+
+    gdb_test "continue" \
+	[multi_line \
+	     "Continuing\\." \
+	     "Error in testing condition for breakpoint ${bp_num}:" \
+	     "Cannot access memory at address 0x0" \
+	     "" \
+	     "Breakpoint ${bp_num}, foo \\(\\) at \[^\r\n\]+:${::bp_line}" \
+	     "${::decimal}\\s+\[^\r\n\]+Breakpoint here\[^\r\n\]+"]
+}
+
+# If we're using a remote target then conditions could be evaulated
+# locally on the host, or on the remote target.  Otherwise, conditions
+# are always evaluated locally (which is what auto will select).
+if { [gdb_is_remote_or_extended_remote_target] } {
+    set cond_eval_modes { "host" "target" }
+} else {
+    set cond_eval_modes { "auto" }
+}
+
+foreach_with_prefix access_type { "char" "short" "int" "long long" } {
+    foreach_with_prefix cond_eval $cond_eval_modes {
+	run_test $cond_eval $access_type
+    }
+}

gdb/testsuite/gdb.base/callfuncs.exp

@@ -49,7 +49,7 @@ proc do_function_calls {prototypes} {
 
     # If any of these calls segv we don't want to affect subsequent tests.
     # E.g., we want to ensure register values are restored.
-    gdb_test_no_output "set unwindonsignal on"
+    gdb_test_no_output "set unwind-on-signal on"
 
     gdb_test "p t_char_values(0,0)" " = 0"
     gdb_test "p t_char_values('a','b')" " = 1"
@@ -240,7 +240,7 @@ proc do_function_calls {prototypes} {
     	"call inferior func with struct - returns char *"
 
     # Restore default value.
-    gdb_test_no_output "set unwindonsignal off"
+    gdb_test_no_output "set unwind-on-signal off"
 }
 
 # Procedure to get current content of all registers.

gdb/testsuite/gdb.base/catch-signal-siginfo-cond.exp

@@ -18,7 +18,7 @@
 #
 # (gdb) continue
 # Continuing.
-# Error in testing breakpoint condition:
+# Error in testing condition for breakpoint NUM:
 # Selected thread is running.
 #
 # Catchpoint 3 (signal SIGUSR1), 0x0000003615e35877 in __GI_raise (sig=10) at raise.c:56

gdb/testsuite/gdb.base/gnu-ifunc.exp

@@ -281,7 +281,7 @@ proc misc_tests {resolver_attr resolver_debug final_debug} {
 
     # Also test a former patch regression:
     # Continuing.
-    # Error in testing breakpoint condition:
+    # Error in testing condition for breakpoint NUM:
     # Attempt to take address of value not located in memory.
     #
     # Breakpoint 2, main () at ./gdb.base/gnu-ifunc.c:33

gdb/testsuite/gdb.base/help.exp

@@ -121,7 +121,7 @@ gdb_test "help info bogus-gdb-command" "Undefined info command: \"bogus-gdb-comm
 gdb_test "help gotcha" "Undefined command: \"gotcha\"\.  Try \"help\"\."
 
 # Test apropos regex.
-gdb_test "apropos \\\(print\[\^\[ bsiedf\\\".-\]\\\)" "handle -- Specify how to handle signals\."
+gdb_test "apropos \\\(print\[\^\[ bsiedf\\\"'.-\]\\\)" "handle -- Specify how to handle signals\."
 # Test apropos >1 word string.
 gdb_test "apropos handle signal" "handle -- Specify how to handle signals\."
 # Test apropos apropos.

gdb/testsuite/gdb.base/infcall-failure.c

@@ -0,0 +1,48 @@
+/* Copyright 2022 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* A function that segfaults (assuming that reads of address zero are
+   prohibited), this is used from within a breakpoint condition.  */
+int
+func_segfault ()
+{
+  volatile int *p = 0;
+  return *p;	/* Segfault here.  */
+}
+
+/* A function in which we will place a breakpoint.  This function is itself
+   then used from within a breakpoint condition.  */
+int
+func_bp ()
+{
+  int res = 0;	/* Second breakpoint.  */
+  return res;
+}
+
+int
+foo ()
+{
+  return 0;	/* First breakpoint.  */
+}
+
+int
+main ()
+{
+  int res = foo ();
+
+  return res;
+}

gdb/testsuite/gdb.base/infcall-failure.exp

@@ -0,0 +1,182 @@
+# Copyright 2022 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Some simple tests of inferior function calls from breakpoint
+# conditions, in a single-threaded inferior.
+#
+# Test what happens when the inferior function (from a breakpoint
+# condition) either hits a nested breakpoint, or segfaults.
+
+standard_testfile
+
+if { [build_executable "failed to prepare" ${binfile} "${srcfile}" \
+	  {debug}] == -1 } {
+    return
+}
+
+set bp_1_line [gdb_get_line_number "First breakpoint"]
+set bp_2_line [gdb_get_line_number "Second breakpoint"]
+set segv_line [gdb_get_line_number "Segfault here"]
+
+# Start GDB based on TARGET_ASYNC and TARGET_NON_STOP, and then runto
+# main.
+proc start_gdb_and_runto_main { target_async target_non_stop } {
+    save_vars { ::GDBFLAGS } {
+	append ::GDBFLAGS \
+	    " -ex \"maint set target-non-stop $target_non_stop\""
+	append ::GDBFLAGS \
+	    " -ex \"maintenance set target-async ${target_async}\""
+
+	clean_restart ${::binfile}
+    }
+
+    if {![runto_main]} {
+	fail "run to main"
+	return -1
+    }
+
+    return 0
+}
+
+# Start GDB according to ASYNC_P and NON_STOP_P, then setup a
+# conditional breakpoint.  The breakpoint condition includes an
+# inferior function call that will itself hit a breakpoint.  Check how
+# GDB reports this to the user.
+proc_with_prefix run_cond_hits_breakpoint_test { async_p non_stop_p } {
+    if { [start_gdb_and_runto_main $async_p $non_stop_p] == -1 } {
+	return
+    }
+
+    # Setup the conditional breakpoint and record its number.
+    gdb_breakpoint "${::srcfile}:${::bp_1_line} if (func_bp ())"
+    set bp_1_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
+		     "get number of first breakpoint"]
+
+    # Setup a breakpoint inside func_bp.
+    gdb_breakpoint "${::srcfile}:${::bp_2_line}"
+    set bp_2_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
+		     "get number of second breakpoint"]
+
+    gdb_test "continue" \
+	[multi_line \
+	     "Continuing\\." \
+	     "" \
+	     "Breakpoint ${bp_2_num}, func_bp \\(\\) at \[^\r\n\]+:${::bp_2_line}" \
+	     "${::decimal}\\s+\[^\r\n\]+Second breakpoint\[^\r\n\]+" \
+	     "Error in testing condition for breakpoint ${bp_1_num}:" \
+	     "The program being debugged stopped while in a function called from GDB\\." \
+	     "Evaluation of the expression containing the function" \
+	     "\\(func_bp\\) will be abandoned\\." \
+	     "When the function is done executing, GDB will silently stop\\."]
+}
+
+# Start GDB according to ASYNC_P and NON_STOP_P, then call an inferior
+# function.  The inferior function being called will itself have a
+# breakpoint within it.  Check how GDB reports this to the user.
+proc_with_prefix run_call_hits_breakpoint_test { async_p non_stop_p } {
+    if { [start_gdb_and_runto_main $async_p $non_stop_p] == -1 } {
+	return
+    }
+
+    # Setup a breakpoint inside func_bp.
+    gdb_breakpoint "${::srcfile}:${::bp_2_line}"
+    set bp_2_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
+		      "get number of second breakpoint"]
+
+
+    gdb_test "call func_bp ()" \
+	[multi_line \
+	     "" \
+	     "Breakpoint ${bp_2_num}, func_bp \\(\\) at \[^\r\n\]+:${::bp_2_line}" \
+	     "${::decimal}\\s+\[^\r\n\]+Second breakpoint\[^\r\n\]+" \
+	     "The program being debugged stopped while in a function called from GDB\\." \
+	     "Evaluation of the expression containing the function" \
+	     "\\(func_bp\\) will be abandoned\\." \
+	     "When the function is done executing, GDB will silently stop\\."]
+}
+
+# Start GDB according to ASYNC_P and NON_STOP_P, then setup a
+# conditional breakpoint.  The breakpoint condition includes an
+# inferior function call that segfaults.  Check how GDB reports this
+# to the user.
+proc_with_prefix run_cond_hits_segfault_test { async_p non_stop_p } {
+    if { [start_gdb_and_runto_main $async_p $non_stop_p] == -1 } {
+	return
+    }
+
+    # This test relies on the inferior segfaulting when trying to
+    # access address zero.
+    if { [is_address_zero_readable] } {
+	return
+    }
+
+    # Setup the conditional breakpoint and record its number.
+    gdb_breakpoint "${::srcfile}:${::bp_1_line} if (func_segfault ())"
+    set bp_1_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
+		     "get number of first breakpoint"]
+
+    gdb_test "continue" \
+	[multi_line \
+	     "Continuing\\." \
+	     "" \
+	     "Program received signal SIGSEGV, Segmentation fault\\." \
+	     "${::hex} in func_segfault \\(\\) at \[^\r\n\]+:${::segv_line}" \
+	     "${::decimal}\\s+\[^\r\n\]+Segfault here\[^\r\n\]+" \
+	     "Error in testing condition for breakpoint ${bp_1_num}:" \
+	     "The program being debugged was signaled while in a function called from GDB\\." \
+	     "GDB remains in the frame where the signal was received\\." \
+	     "To change this behavior use \"set unwind-on-signal on\"\\." \
+	     "Evaluation of the expression containing the function" \
+	     "\\(func_segfault\\) will be abandoned\\." \
+	     "When the function is done executing, GDB will silently stop\\."]
+}
+
+# Start GDB according to ASYNC_P and NON_STOP_P, then call an inferior
+# function.  The inferior function will segfault.  Check how GDB
+# reports this to the user.
+proc_with_prefix run_call_hits_segfault_test { async_p non_stop_p } {
+    if { [start_gdb_and_runto_main $async_p $non_stop_p] == -1 } {
+	return
+    }
+
+    # This test relies on the inferior segfaulting when trying to
+    # access address zero.
+    if { [is_address_zero_readable] } {
+	return
+    }
+
+    gdb_test "call func_segfault ()" \
+	[multi_line \
+	     "" \
+	     "Program received signal SIGSEGV, Segmentation fault\\." \
+	     "${::hex} in func_segfault \\(\\) at \[^\r\n\]+:${::segv_line}" \
+	     "${::decimal}\\s+\[^\r\n\]+Segfault here\[^\r\n\]+" \
+	     "The program being debugged was signaled while in a function called from GDB\\." \
+	     "GDB remains in the frame where the signal was received\\." \
+	     "To change this behavior use \"set unwind-on-signal on\"\\." \
+	     "Evaluation of the expression containing the function" \
+	     "\\(func_segfault\\) will be abandoned\\." \
+	     "When the function is done executing, GDB will silently stop\\."]
+}
+
+foreach_with_prefix target_async { "on" "off" } {
+    foreach_with_prefix target_non_stop { "on" "off" } {
+	run_cond_hits_breakpoint_test $target_async $target_non_stop
+	run_call_hits_breakpoint_test $target_async $target_non_stop
+
+	run_cond_hits_segfault_test $target_async $target_non_stop
+	run_call_hits_segfault_test $target_async $target_non_stop
+    }
+}

gdb/testsuite/gdb.base/infcall-timeout.c

@@ -0,0 +1,36 @@
+/* Copyright 2022 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <unistd.h>
+
+/* This function is called from GDB.  */
+int
+function_that_never_returns ()
+{
+  while (1)
+    sleep (1);
+
+  return 0;
+}
+
+int
+main ()
+{
+  alarm (300);
+
+  return 0;
+}

gdb/testsuite/gdb.base/infcall-timeout.exp

@@ -0,0 +1,98 @@
+# Copyright 2022 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Test GDB's direct-call-timeout setting, that is, ensure that if an
+# inferior function call, invoked from e.g. a 'print' command, takes
+# too long, then GDB can interrupt it, and return control to the user.
+
+standard_testfile
+
+if { [build_executable "failed to prepare" ${binfile} "${srcfile}" \
+	  {debug}] == -1 } {
+    return
+}
+
+# Start GDB according to TARGET_ASYNC and TARGET_NON_STOP, then adjust
+# the direct-call-timeout, and make an inferior function call that
+# will never return.  GDB should eventually timeout and stop the
+# inferior.
+#
+# When UNWIND is "off" the inferior wil be left in the frame where the
+# timeout occurs, otherwise, when UNWIND is "on", GDB should unwind
+# back to the frame where the inferior call was made.
+proc_with_prefix run_test { target_async target_non_stop unwind } {
+    save_vars { ::GDBFLAGS } {
+	append ::GDBFLAGS \
+	    " -ex \"maint set target-non-stop $target_non_stop\""
+	append ::GDBFLAGS \
+	    " -ex \"maintenance set target-async ${target_async}\""
+
+	clean_restart ${::binfile}
+    }
+
+    if {![runto_main]} {
+	fail "run to main"
+	return
+    }
+
+    gdb_test_no_output "set direct-call-timeout 5"
+    gdb_test_no_output "set unwind-on-timeout $unwind"
+
+    if { $unwind } {
+	gdb_test "print function_that_never_returns ()" \
+	    [multi_line \
+		 "Program stopped\\." \
+		 ".*" \
+		 "The program being debugged timed out while in a function called from GDB\\." \
+		 "GDB has restored the context to what it was before the call\\." \
+		 "To change this behavior use \"set unwind-on-timeout off\"\\." \
+		 "Evaluation of the expression containing the function" \
+		 "\\(function_that_never_returns\\) will be abandoned\\."]
+
+	gdb_test "bt" \
+	    "#0\\s+main \\(\\).*"
+    } else {
+	gdb_test "print function_that_never_returns ()" \
+	    [multi_line \
+		 "Program stopped\\." \
+		 ".*" \
+		 "The program being debugged timed out while in a function called from GDB\\." \
+		 "GDB remains in the frame where the timeout occurred\\." \
+		 "To change this behavior use \"set unwind-on-timeout on\"\\." \
+		 "Evaluation of the expression containing the function" \
+		 "\\(function_that_never_returns\\) will be abandoned\\." \
+		 "When the function is done executing, GDB will silently stop\\."]
+
+	gdb_test "bt" \
+	    ".* function_that_never_returns .*<function called from gdb>.*"
+    }
+}
+
+foreach_with_prefix target_async { "on" "off" } {
+
+    if { $target_async == "off" } {
+	# GDB can't timeout while waiting for a thread if the target
+	# runs with async-mode turned off; once the target is running
+	# GDB is effectively blocked until the target stops for some
+	# reason.
+	continue
+    }
+
+    foreach_with_prefix target_non_stop { "on" "off" } {
+	foreach_with_prefix unwind { "on" "off" } {
+	    run_test $target_async $target_non_stop $unwind
+	}
+    }
+}

gdb/testsuite/gdb.base/unwindonsignal.exp

@@ -40,35 +40,51 @@ gdb_test "break stop_here" "Breakpoint \[0-9\]* at .*"
 gdb_test "continue" "Continuing.*Breakpoint \[0-9\]*, stop_here.*" \
     "continue to breakpoint at stop_here"
 
-# Turn on unwindonsignal.
-gdb_test_no_output "set unwindonsignal on" \
-	"setting unwindonsignal"
+# Turn on unwind-on-signal.
+gdb_test_no_output "set unwind-on-signal on" \
+	"setting unwind-on-signal"
 
-gdb_test "show unwindonsignal" \
+gdb_test "show unwind-on-signal" \
 	"Unwinding of stack .* is on." \
-	"showing unwindonsignal"
+	"showing unwind-on-signal"
+
+# For backward compatibility we maintain a 'unwindonsignal' alias for
+# 'unwind-on-signal', check it now.
+gdb_test "show unwindonsignal" \
+    "Unwinding of stack .* is on\\." \
+    "showing unwindonsignal alias"
+
+gdb_test_no_output "set unwindonsignal off" \
+    "setting unwindonsignal alias to off"
+
+gdb_test "show unwind-on-signal" \
+    "Unwinding of stack .* is off\\." \
+    "showing unwind-on-signal after setting via alias"
+
+gdb_test_no_output "set unwindonsignal on" \
+    "setting unwindonsignal alias to on"
 
 # Call function (causing the program to get a signal), and see if gdb handles
 # it properly.
 if {[gdb_test "call gen_signal ()"  \
 	 "\[\r\n\]*The program being debugged was signaled.*" \
-	 "unwindonsignal, inferior function call signaled"] != 0} {
+	 "inferior function call signaled"] != 0} {
     return 0
 }
 
 # Verify the stack got unwound.
 gdb_test "bt" \
     "#0 *\[x0-9a-f in\]*stop_here \\(.*\\) at .*#1 *\[x0-9a-f in\]*main \\(.*\\) at .*" \
-	"unwindonsignal, stack unwound"
+	"stack unwound"
 
 # Verify the dummy frame got removed from dummy_frame_stack.
 gdb_test_multiple "maint print dummy-frames" \
-	"unwindonsignal, dummy frame removed" {
+	"unwind-on-signal, dummy frame removed" {
     -re "\[\r\n\]*.*stack=.*code=.*\[\r\n\]+$gdb_prompt $" {
-	fail "unwindonsignal, dummy frame removed"
+	fail $gdb_test_name
     }
     -re "\[\r\n\]+$gdb_prompt $" {
-	pass "unwindonsignal, dummy frame removed"
+	pass $gdb_test_name
     }
 }
 

gdb/testsuite/gdb.compile/compile-cplus.exp

@@ -129,7 +129,7 @@ gdb_test "return" "\r\n#0  main .*" "return" \
 	 "Make _gdb_expr\\(__gdb_regs\\*\\) return now\\? \\(y or n\\) " "y"
 gdb_test "info sym $infcall_pc" "\r\nNo symbol matches .*" "info sym not found"
 
-gdb_test_no_output "set unwindonsignal on"
+gdb_test_no_output "set unwind-on-signal on"
 gdb_test "compile code *(volatile int *) 0 = 0;" \
     "The program being debugged was signaled while in a function called from GDB\\.\r\nGDB has restored the context to what it was before the call\\.\r\n.*" \
     "compile code segfault second"

gdb/testsuite/gdb.compile/compile.exp

@@ -159,7 +159,7 @@ gdb_test "return" "\r\n#0  main .*" "return" \
 	 "Make _gdb_expr return now\\? \\(y or n\\) " "y"
 gdb_test "info sym $infcall_pc" "\r\nNo symbol matches .*" "info sym not found"
 
-gdb_test_no_output "set unwindonsignal on"
+gdb_test_no_output "set unwind-on-signal on"
 gdb_test "compile code *(volatile int *) 0 = 0;" \
     "The program being debugged was signaled while in a function called from GDB\\.\r\nGDB has restored the context to what it was before the call\\.\r\n.*" \
     "compile code segfault second"

gdb/testsuite/gdb.cp/gdb2495.exp

@@ -104,29 +104,29 @@ if {![runto_main]} {
 # behaviour; it should not.  Test both on and off states.
 
 # Turn on unwind on signal behaviour.
-gdb_test_no_output "set unwindonsignal on"
+gdb_test_no_output "set unwind-on-signal on"
 
 # Check that it is turned on.
-gdb_test "show unwindonsignal" \
+gdb_test "show unwind-on-signal" \
     "signal is received while in a call dummy is on.*" \
     "turn on unwind on signal"
 
 # Check to see if new behaviour interferes with
 # normal signal handling in inferior function calls.
 gdb_test "p exceptions.raise_signal(1)" \
-    "To change this behavior use \"set unwindonsignal off\".*" \
-    "check for unwindonsignal off message"
+    "To change this behavior use \"set unwind-on-signal off\".*" \
+    "check for unwind-on-signal off message"
 
 # And reverse - turn off again.
-gdb_test_no_output "set unwindonsignal off"
+gdb_test_no_output "set unwind-on-signal off"
 
 # Check that it is actually turned off.
-gdb_test "show unwindonsignal" \
+gdb_test "show unwind-on-signal" \
     "signal is received while in a call dummy is off.*" \
     "turn off unwind on signal"
 
 # Check to see if new behaviour interferes with
 # normal signal handling in inferior function calls.
 gdb_test "p exceptions.raise_signal(1)" \
-    "To change this behavior use \"set unwindonsignal on\".*" \
-    "check for unwindonsignal on message"
+    "To change this behavior use \"set unwind-on-signal on\".*" \
+    "check for unwind-on-signal on message"

gdb/testsuite/gdb.fortran/function-calls.exp

@@ -44,7 +44,7 @@ if {![runto [gdb_get_line_number "post_init"]]} {
 }
 
 # Use inspired by gdb.base/callfuncs.exp.
-gdb_test_no_output "set unwindonsignal on"
+gdb_test_no_output "set unwind-on-signal on"
 
 # Baseline: function and subroutine call with no arguments.
 gdb_test "p no_arg()" " = .TRUE."

gdb/testsuite/gdb.mi/mi-syn-frame.exp

@@ -97,7 +97,7 @@ mi_gdb_test "409-stack-list-frames 0 0" \
 # 
 
 mi_gdb_test "410-data-evaluate-expression bar()" \
-  ".*410\\^error,msg=\"The program being debugged was signaled while in a function called from GDB.\\\\nGDB remains in the frame where the signal was received.\\\\nTo change this behavior use \\\\\"set unwindonsignal on\\\\\".\\\\nEvaluation of the expression containing the function\\\\n\\(bar\\) will be abandoned.\\\\nWhen the function is done executing, GDB will silently stop.\"" \
+  ".*410\\^error,msg=\"The program being debugged was signaled while in a function called from GDB.\\\\nGDB remains in the frame where the signal was received.\\\\nTo change this behavior use \\\\\"set unwind-on-signal on\\\\\".\\\\nEvaluation of the expression containing the function\\\\n\\(bar\\) will be abandoned.\\\\nWhen the function is done executing, GDB will silently stop.\"" \
   "call inferior function which raises exception"
 
 mi_gdb_test "411-stack-list-frames" "411\\^done,stack=\\\[frame=\{level=\"0\",addr=\"$hex\",func=\"bar\",file=\".*mi-syn-frame.c\",fullname=\"${fullname_syntax}${srcfile}\",line=\"$decimal\",arch=\"$any\"},frame=\{level=\"1\",addr=\"$hex\",func=\"<function called from gdb>\"\},frame=\{level=\"2\",addr=\"$hex\",func=\"main\",file=\".*mi-syn-frame.c\",fullname=\"${fullname_syntax}${srcfile}\",line=\"$decimal\",arch=\"$any\"}.*\\\]" "backtrace from inferior function at exception"

gdb/testsuite/gdb.python/py-finish-breakpoint.exp

@@ -188,7 +188,7 @@ with_test_prefix "finish in normal frame" {
     gdb_test "python TestBreakpoint()" "TestBreakpoint init" "set BP in condition"
 
     gdb_test "continue" \
-	"test don't stop: 1.*test don't stop: 2.*test stop.*Error in testing breakpoint condition.*The program being debugged stopped while in a function called from GDB.*" \
+	"test don't stop: 1.*test don't stop: 2.*test stop.*Error in testing condition for breakpoint ${::decimal}.*The program being debugged stopped while in a function called from GDB.*" \
 	"stop in condition function"
 
     gdb_test "continue" "Continuing.*" "finish condition evaluation"

gdb/testsuite/gdb.threads/infcall-from-bp-cond-other-thread-event.c

@@ -0,0 +1,135 @@
+/* Copyright 2022 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sched.h>
+
+#define NUM_THREADS 2
+
+pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+
+/* Some global variables to poke, just for something to do.  */
+volatile int global_var_0 = 0;
+volatile int global_var_1 = 0;
+
+/* This flag is updated from GDB.  */
+volatile int raise_signal = 0;
+
+/* Implement the breakpoint condition function.  Release the other thread
+   and try to give the other thread a chance to run.  Then return ANSWER.  */
+int
+condition_core_func (int answer)
+{
+  /* This unlock should release the other thread.  */
+  if (pthread_mutex_unlock (&mutex) != 0)
+    abort ();
+
+  /* And this yield and sleep should (hopefully) give the other thread a
+     chance to run.  This isn't guaranteed of course, but once the other
+     thread does run it should hit a breakpoint, which GDB should
+     (temporarily) ignore, so there's no easy way for us to know the other
+     thread has done what it needs to, thus, yielding and sleeping is the
+     best we can do.  */
+  sched_yield ();
+  sleep (2);
+
+  return answer;
+}
+
+void
+stop_marker ()
+{
+  int a = 100;	/* Final breakpoint here.  */
+}
+
+/* A breakpoint condition function that always returns true.  */
+int
+condition_true_func ()
+{
+  return condition_core_func (1);
+}
+
+/* A breakpoint condition function that always returns false.  */
+int
+condition_false_func ()
+{
+  return condition_core_func (0);
+}
+
+void *
+worker_func (void *arg)
+{
+  volatile int *ptr = 0;
+  int tid = *((int *) arg);
+
+  switch (tid)
+    {
+    case 0:
+      global_var_0 = 11;	/* First thread breakpoint.  */
+      break;
+
+    case 1:
+      if (pthread_mutex_lock (&mutex) != 0)
+	abort ();
+      if (raise_signal)
+	global_var_1 = *ptr;	/* Signal here.  */
+      else
+	global_var_1 = 99;	/* Other thread breakpoint.  */
+      break;
+
+    default:
+      abort ();
+    }
+
+  return NULL;
+}
+
+int
+main ()
+{
+  pthread_t threads[NUM_THREADS];
+  int args[NUM_THREADS];
+
+  /* Set an alarm, just in case the test deadlocks.  */
+  alarm (300);
+
+  /* We want the mutex to start locked.  */
+  if (pthread_mutex_lock (&mutex) != 0)
+    abort ();
+
+  for (int i = 0; i < NUM_THREADS; i++)
+    {
+      args[i] = i;
+      pthread_create (&threads[i], NULL, worker_func, &args[i]);
+    }
+
+  for (int i = 0; i < NUM_THREADS; i++)
+    {
+      void *retval;
+      pthread_join (threads[i], &retval);
+    }
+
+  /* Unlock once we're done, just for cleanliness.  */
+  if (pthread_mutex_unlock (&mutex) != 0)
+    abort ();
+
+  stop_marker ();
+
+  return 0;
+}

gdb/testsuite/gdb.threads/infcall-from-bp-cond-other-thread-event.exp

@@ -0,0 +1,175 @@
+# Copyright 2022 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Test for conditional breakpoints where the breakpoint condition includes
+# an inferior function call.
+#
+# The tests in this script are testing what happens when an event arrives in
+# another thread while GDB is waiting for the inferior function call (in the
+# breakpoint condition) to finish.
+#
+# The expectation is that GDB will queue events for other threads and wait
+# for the inferior function call to complete, if the condition is true, then
+# the conditional breakpoint should be reported first.  The other thread
+# event should of course, not get lost, and should be reported as soon as
+# the user tries to continue the inferior.
+#
+# If the conditional breakpoint ends up not being taken (the condition is
+# false), then the other thread event should be reported immediately.
+#
+# This script tests what happens when the other thread event is (a) the
+# other thread hitting a breakpoint, and (b) the other thread taking a
+# signal (SIGSEGV in this case).
+
+standard_testfile
+
+if { [build_executable "failed to prepare" ${binfile} "${srcfile}" \
+	  {debug pthreads}] == -1 } {
+    return
+}
+
+set cond_bp_line [gdb_get_line_number "First thread breakpoint"]
+set other_bp_line [gdb_get_line_number "Other thread breakpoint"]
+set final_bp_line [gdb_get_line_number "Final breakpoint here"]
+set signal_line [gdb_get_line_number "Signal here"]
+
+# Start GDB based on TARGET_ASYNC and TARGET_NON_STOP, and then runto main.
+proc start_gdb_and_runto_main { target_async target_non_stop } {
+    save_vars { ::GDBFLAGS } {
+	append ::GDBFLAGS \
+	    " -ex \"maint set target-non-stop $target_non_stop\""
+	append ::GDBFLAGS \
+	    " -ex \"maintenance set target-async ${target_async}\""
+
+	clean_restart ${::binfile}
+    }
+
+    if {![runto_main]} {
+	fail "run to main"
+	return -1
+    }
+
+    return 0
+}
+
+# Run a test of GDB's conditional breakpoints, where the conditions include
+# inferior function calls.  While the inferior function call is executing
+# another thread will hit a breakpoint (when OTHER_THREAD_SIGNAL is false),
+# or receive a signal (when OTHER_THREAD_SIGNAL is true).  GDB should report
+# the conditional breakpoint first (if the condition is true), and then
+# report the second thread event once the inferior is continued again.
+#
+# When STOP_AT_COND is true then the conditional breakpoint will have a
+# condition that evaluates to true (and the GDB will stop at the
+# breakpoint), otherwise, the condition will evaluate to false (and GDB will
+# not stop at the breakpoint).
+proc run_condition_test { stop_at_cond other_thread_signal \
+			      target_async target_non_stop } {
+    if { [start_gdb_and_runto_main $target_async \
+	      $target_non_stop] == -1 } {
+	return
+    }
+
+    # Setup the conditional breakpoint.
+    if { $stop_at_cond } {
+	set cond_func "condition_true_func"
+    } else {
+	set cond_func "condition_false_func"
+    }
+    gdb_breakpoint \
+	"${::srcfile}:${::cond_bp_line} if (${cond_func} ())"
+    set cond_bp_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
+			"get number for conditional breakpoint"]
+
+    if { $other_thread_signal } {
+	# Arrange for the other thread to raise a signal while GDB is
+	# evaluating the breakpoint condition.
+	gdb_test_no_output "set raise_signal = 1"
+    } else {
+	# And a breakpoint that will be hit by another thread only once the
+	# breakpoint condition starts to be evaluated.
+	gdb_breakpoint "${::srcfile}:${::other_bp_line}"
+	set other_bp_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
+			      "get number for other breakpoint"]
+    }
+
+    # A final breakpoint once the test has completed.
+    gdb_breakpoint "${::srcfile}:${::final_bp_line}"
+    set final_bp_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
+			  "get number for final breakpoint"]
+
+    if { $stop_at_cond } {
+	# Continue.  The first breakpoint we hit should be the conditional
+	# breakpoint.  The other thread will have hit its breakpoint, but
+	# that will have been deferred until the conditional breakpoint is
+	# reported.
+	gdb_test "continue" \
+	    [multi_line \
+		 "Continuing\\." \
+		 ".*" \
+		 "" \
+		 "Thread ${::decimal} \"\[^\"\r\n\]+\" hit Breakpoint ${cond_bp_num}, worker_func \[^\r\n\]+:${::cond_bp_line}" \
+		 "${::decimal}\\s+\[^\r\n\]+First thread breakpoint\[^\r\n\]+"] \
+	    "hit the conditional breakpoint"
+    }
+
+    if { $other_thread_signal } {
+	# Now continue again, the other thread will now report that it
+	# received a signal.
+	gdb_test "continue" \
+	    [multi_line \
+		 "Continuing\\." \
+		 ".*" \
+		 "Thread ${::decimal} \"\[^\"\r\n\]+\" received signal SIGSEGV, Segmentation fault\\." \
+		 "\\\[Switching to Thread \[^\r\n\]+\\\]" \
+		 "${::hex} in worker_func \[^\r\n\]+:${::signal_line}" \
+		 "${::decimal}\\s+\[^\r\n\]+Signal here\[^\r\n\]+"] \
+	    "received signal in other thread"
+    } else {
+	# Now continue again, the other thread will now report its
+	# breakpoint.
+	gdb_test "continue" \
+	    [multi_line \
+		 "Continuing\\." \
+		 ".*" \
+		 "" \
+		 "Thread ${::decimal} \"\[^\"\r\n\]+\" hit Breakpoint ${other_bp_num}, worker_func \[^\r\n\]+:${::other_bp_line}" \
+		 "${::decimal}\\s+\[^\r\n\]+Other thread breakpoint\[^\r\n\]+"] \
+	    "hit the breakpoint in other thread"
+
+	# Run to the stop marker.
+	gdb_test "continue" \
+	    [multi_line \
+		 "Continuing\\." \
+		 ".*" \
+		 "" \
+		 "Thread ${::decimal} \"\[^\"\r\n\]+\" hit Breakpoint ${final_bp_num}, stop_marker \[^\r\n\]+:${::final_bp_line}" \
+		 "${::decimal}\\s+\[^\r\n\]+Final breakpoint here\[^\r\n\]+"] \
+	    "hit the final breakpoint"
+    }
+
+    gdb_exit
+}
+
+foreach_with_prefix target_async { "on" "off" } {
+    foreach_with_prefix target_non_stop { "on" "off" } {
+	foreach_with_prefix other_thread_signal { true false } {
+	    foreach_with_prefix stop_at_cond { true false } {
+		run_condition_test $stop_at_cond $other_thread_signal \
+		    $target_async $target_non_stop
+	    }
+	}
+    }
+}

gdb/testsuite/gdb.threads/infcall-from-bp-cond-simple.c

@@ -0,0 +1,89 @@
+/* Copyright 2022 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+#include <unistd.h>
+
+#define NUM_THREADS 3
+
+int
+is_matching_tid (int *tid_ptr, int tid_value)
+{
+  return *tid_ptr == tid_value;
+}
+
+int
+return_true ()
+{
+  return 1;
+}
+
+int
+return_false ()
+{
+  return 0;
+}
+
+int
+function_that_segfaults ()
+{
+  int *p = 0;
+  *p = 1;	/* Segfault happens here.   */
+}
+
+int
+function_with_breakpoint ()
+{
+  return 1;	/* Nested breakpoint.  */
+}
+
+void *
+worker_func (void *arg)
+{
+  int a = 42;	/* Breakpoint here.  */
+}
+
+void
+stop_marker ()
+{
+  int b = 99;	/* Stop marker.  */
+}
+
+int
+main ()
+{
+  pthread_t threads[NUM_THREADS];
+  int args[NUM_THREADS];
+
+  alarm (300);
+
+  for (int i = 0; i < NUM_THREADS; i++)
+    {
+      args[i] = i;
+      pthread_create (&threads[i], NULL, worker_func, &args[i]);
+    }
+
+  for (int i = 0; i < NUM_THREADS; i++)
+    {
+      void *retval;
+      pthread_join (threads[i], &retval);
+    }
+
+  stop_marker ();
+
+  return 0;
+}

gdb/testsuite/gdb.threads/infcall-from-bp-cond-simple.exp

@@ -0,0 +1,236 @@
+# Copyright 2022 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Some simple tests of inferior function calls from breakpoint
+# conditions, in multi-threaded inferiors.
+#
+# This test sets up a multi-threaded inferior, and places a breakpoint
+# at a location that many of the threads will reach.  We repeat the
+# test with different conditions, sometimes a single thread should
+# stop at the breakpoint, sometimes multiple threads should stop, and
+# sometime no threads should stop.
+
+standard_testfile
+
+if { [build_executable "failed to prepare" ${binfile} "${srcfile}" \
+	  {debug pthreads}] == -1 } {
+    return
+}
+
+set cond_bp_line [gdb_get_line_number "Breakpoint here"]
+set stop_bp_line [gdb_get_line_number "Stop marker"]
+set nested_bp_line [gdb_get_line_number "Nested breakpoint"]
+set segv_line [gdb_get_line_number "Segfault happens here"]
+
+# Start GDB based on TARGET_ASYNC and TARGET_NON_STOP, and then runto main.
+proc start_gdb_and_runto_main { target_async target_non_stop } {
+    save_vars { ::GDBFLAGS } {
+	append ::GDBFLAGS \
+	    " -ex \"maint set target-non-stop $target_non_stop\""
+	append ::GDBFLAGS \
+	    " -ex \"maintenance set target-async ${target_async}\""
+
+	clean_restart ${::binfile}
+    }
+
+    if {![runto_main]} {
+	fail "run to main"
+	return -1
+    }
+
+    return 0
+}
+
+# Run a test of GDB's conditional breakpoints, where the conditions include
+# inferior function calls.
+#
+# CONDITION is combined (with &&) to some additional logic, and used as the
+# breakpoint condition.
+#
+# N_EXPECTED_HITS is the number of threads that we expect to stop due to
+# CONDITON.
+#
+# MESSAGE is used as a test name prefix.
+proc run_condition_test { message n_expected_hits condition \
+			      target_async target_non_stop } {
+    with_test_prefix $message {
+
+	if { [start_gdb_and_runto_main $target_async \
+		  $target_non_stop] == -1 } {
+	    return
+	}
+
+	# Use this convenience variable to track how often the
+	# breakpoint condition has been evaluated, this should be once
+	# per thread.
+	gdb_test "set \$n_cond_eval = 0"
+
+	# Setup the conditional breakpoint.
+	gdb_breakpoint \
+	    "${::srcfile}:${::cond_bp_line} if ((++\$n_cond_eval) ${condition})"
+
+	# And a breakpoint that we hit when the test is over, this one is
+	# not conditional.  Only the main thread gets here once all the
+	# other threads have finished.
+	gdb_breakpoint "${::srcfile}:${::stop_bp_line}"
+
+	# The number of times we stop at the conditional breakpoint.
+	set n_hit_condition 0
+
+	# Now keep 'continue'-ing GDB until all the threads have finished
+	# and we reach the stop_marker breakpoint.
+	gdb_test_multiple "continue" "spot all breakpoint hits" {
+	    -re " worker_func \[^\r\n\]+${::srcfile}:${::cond_bp_line}\r\n${::decimal}\\s+\[^\r\n\]+Breakpoint here\[^\r\n\]+\r\n${::gdb_prompt} $" {
+		incr n_hit_condition
+		send_gdb "continue\n"
+		exp_continue
+	    }
+
+	    -re " stop_marker \[^\r\n\]+${::srcfile}:${::stop_bp_line}\r\n${::decimal}\\s+\[^\r\n\]+Stop marker\[^\r\n\]+\r\n${::gdb_prompt} $" {
+		pass $gdb_test_name
+	    }
+	}
+
+	gdb_assert { $n_hit_condition == $n_expected_hits } \
+	    "stopped at breakpoint the expected number of times"
+
+	# Ensure the breakpoint condition was evaluated once per thread.
+	gdb_test "print \$n_cond_eval" "= 3" "condition was evaluated twice"
+    }
+}
+
+# Check that after handling a conditional breakpoint (where the condition
+# includes an inferior call), it is still possible to kill the running
+# inferior, and then restart the inferior.
+#
+# At once point doing this would result in GDB giving an assertion error.
+proc_with_prefix run_kill_and_restart_test { target_async target_non_stop } {
+    # This test relies on the 'start' command, which is not possible with
+    # the plain 'remote' target.
+    if {[target_info gdb_protocol] == "remote"} {
+	return
+    }
+
+    if { [start_gdb_and_runto_main $target_async \
+	      $target_non_stop] == -1 } {
+	return
+    }
+
+    # Setup the conditional breakpoint.
+    gdb_breakpoint \
+	"${::srcfile}:${::cond_bp_line} if (is_matching_tid (arg, 1))"
+    gdb_continue_to_breakpoint "worker_func"
+
+    # Now kill the program being debugged.
+    gdb_test "kill" "" "kill process" \
+	"Kill the program being debugged.*y or n. $" "y"
+
+    # Check we can restart the inferior.  At one point this would trigger an
+    # assertion.
+    gdb_test "start" ".*"
+}
+
+# Create a conditional breakpoint which includes a call to a function that
+# segfaults.  Run GDB and check what happens when the inferior segfaults
+# during the inferior call.
+proc_with_prefix run_bp_cond_segfaults { target_async target_non_stop } {
+    if { [start_gdb_and_runto_main $target_async \
+	      $target_non_stop] == -1 } {
+	return
+    }
+
+    # This test relies on the inferior segfaulting when trying to
+    # access address zero.
+    if { [is_address_zero_readable] } {
+	return
+    }
+
+    # Setup the conditional breakpoint, include a call to
+    # 'function_that_segfaults', which triggers the segfault.
+    gdb_breakpoint \
+	"${::srcfile}:${::cond_bp_line} if (is_matching_tid (arg, 0) && function_that_segfaults ())"
+    set bp_1_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
+		      "get number of conditional breakpoint"]
+
+    gdb_test "continue" \
+	[multi_line \
+	     "Continuing\\." \
+	     ".*" \
+	     "Thread ${::decimal} \"infcall-from-bp\" received signal SIGSEGV, Segmentation fault\\." \
+	     "${::hex} in function_that_segfaults \\(\\) at \[^\r\n\]+:${::segv_line}" \
+	     "${::decimal}\\s+\[^\r\n\]+Segfault happens here\[^\r\n\]+" \
+	     "Error in testing condition for breakpoint ${bp_1_num}:" \
+	     "The program being debugged was signaled while in a function called from GDB\\." \
+	     "GDB remains in the frame where the signal was received\\." \
+	     "To change this behavior use \"set unwind-on-signal on\"\\." \
+	     "Evaluation of the expression containing the function" \
+	     "\\(function_that_segfaults\\) will be abandoned\\." \
+	     "When the function is done executing, GDB will silently stop\\."]
+}
+
+# Create a conditional breakpoint which includes a call to a function that
+# itself has a breakpoint set within it.  Run GDB and check what happens
+# when GDB hits the nested breakpoint.
+proc_with_prefix run_bp_cond_hits_breakpoint { target_async target_non_stop } {
+    if { [start_gdb_and_runto_main $target_async \
+	      $target_non_stop] == -1 } {
+	return
+    }
+
+    # Setup the conditional breakpoint, include a call to
+    # 'function_with_breakpoint' in which we will shortly place a
+    # breakpoint.
+    gdb_breakpoint \
+	"${::srcfile}:${::cond_bp_line} if (is_matching_tid (arg, 0) && function_with_breakpoint ())"
+    set bp_1_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
+		      "get number of conditional breakpoint"]
+
+    gdb_breakpoint "${::srcfile}:${::nested_bp_line}"
+    set bp_2_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
+		      "get number of nested breakpoint"]
+
+    gdb_test "continue" \
+	[multi_line \
+	     "Continuing\\." \
+	     ".*" \
+	     "Thread ${::decimal} \"infcall-from-bp\" hit Breakpoint ${bp_2_num}, function_with_breakpoint \\(\\) at \[^\r\n\]+:${::nested_bp_line}" \
+	     "${::decimal}\\s+\[^\r\n\]+Nested breakpoint\[^\r\n\]+" \
+	     "Error in testing condition for breakpoint ${bp_1_num}:" \
+	     "The program being debugged stopped while in a function called from GDB\\." \
+	     "Evaluation of the expression containing the function" \
+	     "\\(function_with_breakpoint\\) will be abandoned\\." \
+	     "When the function is done executing, GDB will silently stop\\."]
+}
+
+foreach_with_prefix target_async { "on" "off" } {
+    foreach_with_prefix target_non_stop { "on" "off" } {
+	run_condition_test "exactly one thread is hit" \
+	    1 "&& is_matching_tid (arg, 1)" \
+	    $target_async $target_non_stop
+	run_condition_test "exactly two threads are hit" \
+	    2 "&& (is_matching_tid (arg, 0) || is_matching_tid (arg, 2))" \
+	    $target_async $target_non_stop
+	run_condition_test "all three threads are hit" \
+	    3 "|| return_true ()" \
+	    $target_async $target_non_stop
+	run_condition_test "no thread is hit" \
+	    0 "&& return_false ()" \
+	    $target_async $target_non_stop
+
+	run_kill_and_restart_test $target_async $target_non_stop
+	run_bp_cond_segfaults $target_async $target_non_stop
+	run_bp_cond_hits_breakpoint $target_async $target_non_stop
+    }
+}

gdb/testsuite/gdb.threads/infcall-from-bp-cond-single.c

@@ -0,0 +1,139 @@
+/* Copyright 2022 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+#include <unistd.h>
+#include <semaphore.h>
+#include <stdlib.h>
+
+#define NUM_THREADS 5
+
+/* Semaphores, used to track when threads have started, and to control
+   when the threads finish.  */
+sem_t startup_semaphore;
+sem_t finish_semaphore;
+
+/* Mutex to control when the first worker thread hit a breakpoint
+   location.  */
+pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+
+/* Global variable to poke, just so threads have something to do.  */
+volatile int global_var = 0;
+
+int
+return_true ()
+{
+  return 1;
+}
+
+int
+return_false ()
+{
+  return 0;
+}
+
+void *
+worker_func (void *arg)
+{
+  int tid = *((int *) arg);
+
+  switch (tid)
+    {
+    case 0:
+      /* Wait for MUTEX to become available, then pass through the
+	 conditional breakpoint location.  */
+      if (pthread_mutex_lock (&mutex) != 0)
+	abort ();
+      global_var = 99;	/* Conditional breakpoint here.  */
+      if (pthread_mutex_unlock (&mutex) != 0)
+	abort ();
+      break;
+
+    default:
+      /* Notify the main thread that the thread has started, then wait for
+	 the main thread to tell us to finish.  */
+      sem_post (&startup_semaphore);
+      if (sem_wait (&finish_semaphore) != 0)
+	abort ();
+      break;
+    }
+}
+
+void
+stop_marker ()
+{
+  global_var = 99;	/* Stop marker.  */
+}
+
+int
+main ()
+{
+  pthread_t threads[NUM_THREADS];
+  int args[NUM_THREADS];
+  void *retval;
+
+  /* An alarm, just in case the thread deadlocks.  */
+  alarm (300);
+
+  /* Semaphore initialization.  */
+  if (sem_init (&startup_semaphore, 0, 0) != 0)
+    abort ();
+  if (sem_init (&finish_semaphore, 0, 0) != 0)
+    abort ();
+
+  /* Lock MUTEX, this prevents the first worker thread from rushing ahead.  */
+  if (pthread_mutex_lock (&mutex) != 0)
+    abort ();
+
+  /* Worker thread creation.  */
+  for (int i = 0; i < NUM_THREADS; i++)
+    {
+      args[i] = i;
+      pthread_create (&threads[i], NULL, worker_func, &args[i]);
+    }
+
+  /* Wait for every thread (other than the first) to tell us it has started
+     up.  */
+  for (int i = 1; i < NUM_THREADS; i++)
+    {
+      if (sem_wait (&startup_semaphore) != 0)
+	abort ();
+    }
+
+  /* Unlock the first thread so it can proceed.  */
+  if (pthread_mutex_unlock (&mutex) != 0)
+    abort ();
+
+  /* Wait for the first thread only.  */
+  pthread_join (threads[0], &retval);
+
+  /* Now post FINISH_SEMAPHORE to allow all the other threads to finish.  */
+  for (int i = 1; i < NUM_THREADS; i++)
+    sem_post (&finish_semaphore);
+
+  /* Now wait for the remaining threads to complete.  */
+  for (int i = 1; i < NUM_THREADS; i++)
+    pthread_join (threads[i], &retval);
+
+  /* Semaphore cleanup.  */
+  sem_destroy (&finish_semaphore);
+  sem_destroy (&startup_semaphore);
+
+  stop_marker ();
+
+  return 0;
+}

gdb/testsuite/gdb.threads/infcall-from-bp-cond-single.exp

@@ -0,0 +1,119 @@
+# Copyright 2022 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# This test reprocuces bug gdb/28942, performing an inferior function
+# call from a breakpoint condition in a multi-threaded inferior.
+#
+# The important part of this test is that, when the conditional
+# breakpoint is hit, and the condition (which includes an inferior
+# function call) is evaluated, the other threads are running.
+
+standard_testfile
+
+if { [build_executable "failed to prepare" ${binfile} "${srcfile}" \
+	  {debug pthreads}] == -1 } {
+    return
+}
+
+set cond_bp_line [gdb_get_line_number "Conditional breakpoint here"]
+set final_bp_line [gdb_get_line_number "Stop marker"]
+
+# Start GDB based on TARGET_ASYNC and TARGET_NON_STOP, and then runto main.
+proc start_gdb_and_runto_main { target_async target_non_stop } {
+    save_vars { ::GDBFLAGS } {
+	append ::GDBFLAGS \
+	    " -ex \"maint set target-non-stop $target_non_stop\""
+	append ::GDBFLAGS \
+	    " -ex \"maintenance set target-async ${target_async}\""
+
+	clean_restart ${::binfile}
+    }
+
+    if {![runto_main]} {
+	fail "run to main"
+	return -1
+    }
+
+    return 0
+}
+
+# Run a test of GDB's conditional breakpoints, where the conditions include
+# inferior function calls.
+#
+# CONDITION is combined (with &&) to some additional logic, and used as the
+# breakpoint condition.
+#
+# N_EXPECTED_HITS is the number of threads that we expect to stop due to
+# CONDITON.
+#
+# MESSAGE is used as a test name prefix.
+proc run_condition_test { stop_at_cond \
+			      target_async target_non_stop } {
+    if { [start_gdb_and_runto_main $target_async \
+	      $target_non_stop] == -1 } {
+	return
+    }
+
+    # Setup the conditional breakpoint.
+    if { $stop_at_cond } {
+	set cond_func "return_true"
+    } else {
+	set cond_func "return_false"
+    }
+    gdb_breakpoint \
+	"${::srcfile}:${::cond_bp_line} if (${cond_func} ())"
+    set cond_bp_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
+			"get number for conditional breakpoint"]
+
+    # And a breakpoint that we hit when the test is over, this one is
+    # not conditional.
+    gdb_breakpoint "${::srcfile}:${::final_bp_line}"
+    set final_bp_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
+			  "get number for final breakpoint"]
+
+    if { $stop_at_cond } {
+	# Continue.  The first breakpoint we hit should be the conditional
+	# breakpoint.  The other thread will have hit its breakpoint, but
+	# that will have been deferred until the conditional breakpoint is
+	# reported.
+	gdb_test "continue" \
+	    [multi_line \
+		 "Continuing\\." \
+		 ".*" \
+		 "" \
+		 "Thread ${::decimal} \"\[^\"\r\n\]+\" hit Breakpoint ${cond_bp_num}, worker_func \[^\r\n\]+:${::cond_bp_line}" \
+		 "${::decimal}\\s+\[^\r\n\]+Conditional breakpoint here\[^\r\n\]+"] \
+	    "hit the conditional breakpoint"
+    }
+
+    # Run to the stop marker.
+    gdb_test "continue" \
+	[multi_line \
+	     "Continuing\\." \
+	     ".*" \
+	     "" \
+	     "Thread ${::decimal} \"\[^\"\r\n\]+\" hit Breakpoint ${final_bp_num}, stop_marker \[^\r\n\]+:${::final_bp_line}" \
+	     "${::decimal}\\s+\[^\r\n\]+Stop marker\[^\r\n\]+"] \
+	"hit the final breakpoint"
+}
+
+foreach_with_prefix target_async { "on" "off" } {
+    foreach_with_prefix target_non_stop { "on" "off" } {
+	foreach_with_prefix stop_at_cond { true false } {
+	    run_condition_test $stop_at_cond \
+		$target_async $target_non_stop
+	}
+    }
+}

gdb/testsuite/gdb.threads/infcall-from-bp-cond-timeout.c

@@ -0,0 +1,169 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2022 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <stdio.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <semaphore.h>
+
+#define NUM_THREADS 5
+
+/* Semaphores, used to track when threads have started, and to control
+   when the threads finish.  */
+sem_t startup_semaphore;
+sem_t finish_semaphore;
+sem_t thread_1_semaphore;
+sem_t thread_2_semaphore;
+
+/* Mutex to control when the first worker thread hit a breakpoint
+   location.  */
+pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+
+/* Global variable to poke, just so threads have something to do.  */
+volatile int global_var = 0;
+
+int
+condition_func ()
+{
+  /* Let thread 2 run.  */
+  if (sem_post (&thread_2_semaphore) != 0)
+    abort ();
+
+  /* Wait for thread 2 to complete its actions.  */
+  if (sem_wait (&thread_1_semaphore) != 0)
+    abort ();
+
+  return 1;
+}
+
+void
+do_segfault ()
+{
+  volatile int *p = 0;
+  *p = 0;	/* Segfault here.  */
+}
+
+void *
+worker_func (void *arg)
+{
+  int tid = *((int *) arg);
+
+  /* Let the main thread know that this worker has started.  */
+  if (sem_post (&startup_semaphore) != 0)
+    abort ();
+
+  switch (tid)
+    {
+    case 0:
+      /* Wait for MUTEX to become available, then pass through the
+	 conditional breakpoint location.  */
+      if (pthread_mutex_lock (&mutex) != 0)
+	abort ();
+      global_var = 99;	/* Conditional breakpoint here.  */
+      if (pthread_mutex_unlock (&mutex) != 0)
+	abort ();
+      break;
+
+    case 1:
+      if (sem_wait (&thread_2_semaphore) != 0)
+	abort ();
+      do_segfault ();
+      if (sem_post (&thread_1_semaphore) != 0)
+	abort ();
+
+      /* Fall through.  */
+    default:
+      /* Wait until we are allowed to finish.  */
+      if (sem_wait (&finish_semaphore) != 0)
+	abort ();
+      break;
+    }
+}
+
+void
+stop_marker ()
+{
+  global_var = 99;	/* Stop marker.  */
+}
+
+/* The main program entry point.  */
+
+int
+main ()
+{
+  pthread_t threads[NUM_THREADS];
+  int args[NUM_THREADS];
+  void *retval;
+
+  /* An alarm, just in case the thread deadlocks.  */
+  alarm (300);
+
+  /* Semaphore initialization.  */
+  if (sem_init (&startup_semaphore, 0, 0) != 0)
+    abort ();
+  if (sem_init (&finish_semaphore, 0, 0) != 0)
+    abort ();
+  if (sem_init (&thread_1_semaphore, 0, 0) != 0)
+    abort ();
+  if (sem_init (&thread_2_semaphore, 0, 0) != 0)
+    abort ();
+
+  /* Lock MUTEX, this prevents the first worker thread from rushing ahead.  */
+  if (pthread_mutex_lock (&mutex) != 0)
+    abort ();
+
+  /* Worker thread creation.  */
+  for (int i = 0; i < NUM_THREADS; i++)
+    {
+      args[i] = i;
+      pthread_create (&threads[i], NULL, worker_func, &args[i]);
+    }
+
+  /* Wait for every thread to start.  */
+  for (int i = 0; i < NUM_THREADS; i++)
+    {
+      if (sem_wait (&startup_semaphore) != 0)
+	abort ();
+    }
+
+  /* Unlock the first thread so it can proceed.  */
+  if (pthread_mutex_unlock (&mutex) != 0)
+    abort ();
+
+  /* Wait for the first thread only.  */
+  pthread_join (threads[0], &retval);
+
+  /* Now post FINISH_SEMAPHORE to allow all the other threads to finish.  */
+  for (int i = 1; i < NUM_THREADS; i++)
+    sem_post (&finish_semaphore);
+
+  /* Now wait for the remaining threads to complete.  */
+  for (int i = 1; i < NUM_THREADS; i++)
+    pthread_join (threads[i], &retval);
+
+  /* Semaphore cleanup.  */
+  sem_destroy (&finish_semaphore);
+  sem_destroy (&startup_semaphore);
+  sem_destroy (&thread_1_semaphore);
+  sem_destroy (&thread_2_semaphore);
+
+  stop_marker ();
+
+  return 0;
+}

gdb/testsuite/gdb.threads/infcall-from-bp-cond-timeout.exp

@@ -0,0 +1,174 @@
+# Copyright 2020 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Tests inferior calls executed from a breakpoint condition in
+# a multi-threaded program.
+#
+# This test has the inferior function call timeout, and checks how GDB
+# handles this situation.
+
+standard_testfile
+
+if { [build_executable "failed to prepare" ${binfile} "${srcfile}" \
+	  {debug pthreads}] } {
+    return
+}
+
+set cond_bp_line [gdb_get_line_number "Conditional breakpoint here"]
+set final_bp_line [gdb_get_line_number "Stop marker"]
+set segfault_line [gdb_get_line_number "Segfault here"]
+
+# Setup GDB based on TARGET_ASYNC and TARGET_NON_STOP.  Setup some
+# breakpoints in the inferior, one of which has an inferior call
+# within its condition.
+#
+# Continue GDB, the breakpoint with inferior call will be hit, but the
+# inferior call will never return.  We expect GDB to timeout.
+#
+# The reason that the inferior call never completes is that a second
+# thread, on which the inferior call relies, either hits a breakpoint
+# (when OTHER_THREAD_BP is true), or crashes (when OTHER_THREAD_BP is
+# false).
+#
+# When UNWIND is "on" GDB will unwind the thread which performed the
+# inferior function call back to the state where the inferior call was
+# made (when the inferior call times out).  Otherwise, when UNWIND is
+# "off", the inferior is left in the frame where the timeout occurred.
+proc run_test { target_async target_non_stop other_thread_bp unwind } {
+    save_vars { ::GDBFLAGS } {
+	append ::GDBFLAGS " -ex \"maint set target-non-stop $target_non_stop\""
+	append ::GDBFLAGS " -ex \"maintenance set target-async ${target_async}\""
+
+	clean_restart ${::binfile}
+    }
+
+    if {![runto_main]} {
+	fail "run to main"
+	return
+    }
+
+    # The default timeout for indirect inferior calls (e.g. inferior
+    # calls for conditional breakpoint expressions) is pretty high.
+    # We don't want the test to take too long, so reduce this.
+    #
+    # However, the test relies on a second thread hitting some event
+    # (either a breakpoint or signal) before this timeout expires.
+    #
+    # There is a chance that on a really slow system this might not
+    # happen, in which case the test might fail.
+    #
+    # However, we still allocate 5 seconds, which feels like it should
+    # be enough time in most cases, but maybe we need to do something
+    # smarter here?  Possibly we could have some initial run where the
+    # inferior doesn't timeout, but does do the same interaction
+    # between threads, we could time that, and use that as the basis
+    # for this timeout.  For now though, we just hope 5 seconds is
+    # enough.
+    gdb_test_no_output "set indirect-call-timeout 5"
+    gdb_test_no_output "set unwind-on-timeout $unwind"
+
+    gdb_breakpoint \
+	"${::srcfile}:${::cond_bp_line} if (condition_func ())"
+    set bp_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
+		    "get number for conditional breakpoint"]
+
+    gdb_breakpoint "${::srcfile}:${::final_bp_line}"
+    set final_bp_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
+			  "get number for final breakpoint"]
+
+    # The thread performing an inferior call relies on a second
+    # thread.  The second thread will segfault unless it hits a
+    # breakpoint first.  In either case the initial thread will not
+    # complete its inferior call.
+    if { $other_thread_bp } {
+	gdb_breakpoint "${::srcfile}:${::segfault_line}"
+	set segfault_bp_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
+				 "get number for segfault breakpoint"]
+    }
+
+    if { $unwind } {
+	gdb_test "continue" \
+	    [multi_line \
+		 "Thread ${::decimal} \"\[^\r\n\"\]+\" stopped\\." \
+		 ".*" \
+		 "Error in testing condition for breakpoint ${bp_num}:" \
+		 "The program being debugged timed out while in a function called from GDB\\." \
+		 "GDB has restored the context to what it was before the call\\." \
+		 "To change this behavior use \"set unwind-on-timeout off\"\\." \
+		 "Evaluation of the expression containing the function" \
+		 "\\(condition_func\\) will be abandoned\\." \
+		 "" \
+		 "Thread ${::decimal}\[^\r\n\]*hit Breakpoint ${bp_num}, \[^\r\n\]+" \
+		 "\[^\r\n\]+ Conditional breakpoint here\\. \[^\r\n\]+"] \
+	    "expected timeout waiting for inferior call to complete"
+    } else {
+	gdb_test "continue" \
+	    [multi_line \
+		 "Thread ${::decimal} \"\[^\r\n\"\]+\" stopped\\." \
+		 ".*" \
+		 "Error in testing condition for breakpoint ${bp_num}:" \
+		 "The program being debugged timed out while in a function called from GDB\\." \
+		 "GDB remains in the frame where the timeout occurred\\." \
+		 "To change this behavior use \"set unwind-on-timeout on\"\\." \
+		 "Evaluation of the expression containing the function" \
+		 "\\(condition_func\\) will be abandoned\\." \
+		 "When the function is done executing, GDB will silently stop\\."] \
+	    "expected timeout waiting for inferior call to complete"
+    }
+
+    # Remember that other thread that either crashed (with a segfault)
+    # or hit a breakpoint?  Now that the inferior call has timed out,
+    # if we try to resume then we should see the pending event from
+    # that other thread.
+    if { $other_thread_bp } {
+	gdb_test "continue" \
+	    [multi_line \
+		 "Continuing\\." \
+		 ".*" \
+		 "" \
+		 "Thread ${::decimal} \"\[^\"\r\n\]+\" hit Breakpoint ${segfault_bp_num}, do_segfault \[^\r\n\]+:${::segfault_line}" \
+		 "${::decimal}\\s+\[^\r\n\]+Segfault here\[^\r\n\]+"] \
+	    "hit the segfault breakpoint"
+    } else {
+	gdb_test "continue" \
+	    [multi_line \
+		 "Continuing\\." \
+		 ".*" \
+		 "Thread ${::decimal} \"infcall-from-bp\" received signal SIGSEGV, Segmentation fault\\." \
+		 "\\\[Switching to Thread \[^\r\n\]+\\\]" \
+		 "${::hex} in do_segfault \\(\\) at \[^\r\n\]+:${::segfault_line}" \
+		 "${::decimal}\\s+\[^\r\n\]+Segfault here\[^\r\n\]+"] \
+	    "hit the segfault"
+    }
+}
+
+foreach_with_prefix target_async {"on" "off" } {
+
+    if { $target_async == "off" } {
+	# GDB can't timeout while waiting for a thread if the target
+	# runs with async-mode turned off; once the target is running
+	# GDB is effectively blocked until the target stops for some
+	# reason.
+	continue
+    }
+
+    foreach_with_prefix target_non_stop {"off" "on"} {
+	foreach_with_prefix unwind {"off" "on"} {
+	    foreach_with_prefix other_thread_bp { true false } {
+		run_test $target_async $target_non_stop $other_thread_bp $unwind
+	    }
+	}
+    }
+}

gdb/testsuite/gdb.threads/thread-unwindonsignal.exp

@@ -13,7 +13,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-# Test use of unwindonsignal when a hand function call that gets interrupted
+# Test use of unwind-on-signal when a hand function call that gets interrupted
 # by a signal in another thread.
 
 set NR_THREADS 4
@@ -52,12 +52,12 @@ gdb_test "continue" \
 # We want the main thread (hand_call_with_signal) and
 # thread 1 (sigabrt_handler) to both run.
 
-# Do turn on unwindonsignal.
+# Do turn on unwind-on-signal.
 # We want to test gdb handling of the current thread changing when
 # unwindonsignal is in effect.
-gdb_test_no_output "set unwindonsignal on" \
+gdb_test_no_output "set unwind-on-signal on" \
 	"setting unwindonsignal"
-gdb_test "show unwindonsignal" \
+gdb_test "show unwind-on-signal" \
 	"Unwinding of stack .* is on." \
 	"showing unwindonsignal"
 

gdb/testsuite/lib/gdb.exp

@@ -9332,5 +9332,13 @@ proc has_dependency { file dep } {
     return [regexp $dep $output]
 }
 
+# Return true if we are currently testing the 'remote' or
+# 'extended-remote' targets.
+proc gdb_is_remote_or_extended_remote_target {} {
+    return [target_info exists gdb_protocol]
+	   && ([target_info gdb_protocol] == "remote"
+	       || [target_info gdb_protocol] == "extended-remote")
+}
+
 # Always load compatibility stuff.
 load_lib future.exp

gdbserver/ax.cc

@@ -1112,22 +1112,26 @@ gdb_eval_agent_expr (struct eval_agent_expr_context *ctx,
 	  break;
 
 	case gdb_agent_op_ref8:
-	  agent_mem_read (ctx, cnv.u8.bytes, (CORE_ADDR) top, 1);
+	  if (agent_mem_read (ctx, cnv.u8.bytes, (CORE_ADDR) top, 1) != 0)
+	    return expr_eval_invalid_memory_access;
 	  top = cnv.u8.val;
 	  break;
 
 	case gdb_agent_op_ref16:
-	  agent_mem_read (ctx, cnv.u16.bytes, (CORE_ADDR) top, 2);
+	  if (agent_mem_read (ctx, cnv.u16.bytes, (CORE_ADDR) top, 2) != 0)
+	    return expr_eval_invalid_memory_access;
 	  top = cnv.u16.val;
 	  break;
 
 	case gdb_agent_op_ref32:
-	  agent_mem_read (ctx, cnv.u32.bytes, (CORE_ADDR) top, 4);
+	  if (agent_mem_read (ctx, cnv.u32.bytes, (CORE_ADDR) top, 4) != 0)
+	    return expr_eval_invalid_memory_access;
 	  top = cnv.u32.val;
 	  break;
 
 	case gdb_agent_op_ref64:
-	  agent_mem_read (ctx, cnv.u64.bytes, (CORE_ADDR) top, 8);
+	  if (agent_mem_read (ctx, cnv.u64.bytes, (CORE_ADDR) top, 8) != 0)
+	    return expr_eval_invalid_memory_access;
 	  top = cnv.u64.val;
 	  break;
 

gdbserver/ax.h

@@ -41,7 +41,8 @@ enum eval_result_type
     expr_eval_unhandled_opcode,
     expr_eval_unrecognized_opcode,
     expr_eval_divide_by_zero,
-    expr_eval_invalid_goto
+    expr_eval_invalid_goto,
+    expr_eval_invalid_memory_access
   };
 
 struct agent_expr

gdbserver/tracepoint.cc

@@ -4914,8 +4914,7 @@ condition_true_at_tracepoint (struct tracepoint_hit_ctx *ctx,
   return (value ? 1 : 0);
 }
 
-/* Do memory copies for bytecodes.  */
-/* Do the recording of memory blocks for actions and bytecodes.  */
+/* See tracepoint.h.  */
 
 int
 agent_mem_read (struct eval_agent_expr_context *ctx,
@@ -4927,10 +4926,7 @@ agent_mem_read (struct eval_agent_expr_context *ctx,
 
   /* If a 'to' buffer is specified, use it.  */
   if (to != NULL)
-    {
-      read_inferior_memory (from, to, len);
-      return 0;
-    }
+    return read_inferior_memory (from, to, len);
 
   /* Otherwise, create a new memory block in the trace buffer.  */
   while (remaining > 0)
@@ -4951,7 +4947,8 @@ agent_mem_read (struct eval_agent_expr_context *ctx,
       memcpy (mspace, &blocklen, sizeof (blocklen));
       mspace += sizeof (blocklen);
       /* Record the memory block proper.  */
-      read_inferior_memory (from, mspace, blocklen);
+      if (read_inferior_memory (from, mspace, blocklen) != 0)
+	return 1;
       trace_debug ("%d bytes recorded", blocklen);
       remaining -= blocklen;
       from += blocklen;

gdbserver/tracepoint.h

@@ -161,8 +161,13 @@ void gdb_agent_about_to_close (int pid);
 struct traceframe;
 struct eval_agent_expr_context;
 
-/* Do memory copies for bytecodes.  */
-/* Do the recording of memory blocks for actions and bytecodes.  */
+/* When TO is not NULL, do memory copies for bytecodes, read LEN bytes
+   starting at address FROM, and place the result in the buffer TO.
+   Return 0 on success, otherwise a non-zero error code.
+
+   When TO is NULL, do the recording of memory blocks for actions and
+   bytecodes into a new traceframe block.  Return 0 on success, otherwise,
+   return 1 if there is an error.  */
 
 int agent_mem_read (struct eval_agent_expr_context *ctx,
 		    unsigned char *to, CORE_ADDR from,