Add ability to suspend all events via SUSPEND_ALL (#3019)

* Add ability to suspend all events via SUSPEND_ALL

* fix mypy

pwndbg/dbg/__init__.py

@@ -1001,6 +1001,7 @@ class EventType(Enum):
           debugged. In GDB terminology, these are called `objfile`s.
     """
 
+    SUSPEND_ALL = -1
     START = 0
     STOP = 1
     EXIT = 2
@@ -1098,6 +1099,19 @@ class Debugger:
         """
         raise NotImplementedError()
 
+    @contextlib.contextmanager
+    def ctx_suspend_events(self, ty: EventType) -> Iterator[None]:
+        """
+        Context manager for temporarily suspending and resuming the delivery of events
+        of a given type.
+        """
+
+        self.suspend_events(ty)
+        try:
+            yield
+        finally:
+            self.resume_events(ty)
+
     def suspend_events(self, ty: EventType) -> None:
         """
         Suspend delivery of all events of the given type until it is resumed

pwndbg/dbg/gdb/__init__.py

@@ -1298,6 +1298,11 @@ def _gdb_event_class_from_event_type(ty: pwndbg.dbg_mod.EventType) -> Any:
         return gdb.events.memory_changed
     elif ty == pwndbg.dbg_mod.EventType.REGISTER_CHANGED:
         return gdb.events.register_changed
+    elif ty == pwndbg.dbg_mod.EventType.SUSPEND_ALL:
+        assert hasattr(
+            gdb.events, "suspend_all"
+        ), "gdb.events.suspend_all is missing. Did the Pwndbg GDB event code not get loaded?"
+        return gdb.events.suspend_all
 
     raise NotImplementedError(f"unknown event type {ty}")
 
@@ -1652,6 +1657,8 @@ class GDB(pwndbg.dbg_mod.Debugger):
             return pwndbg.gdblib.events.mem_changed
         elif ty == pwndbg.dbg_mod.EventType.REGISTER_CHANGED:
             return pwndbg.gdblib.events.reg_changed
+        elif ty == pwndbg.dbg_mod.EventType.SUSPEND_ALL:
+            raise RuntimeError("invalid usage, this event is not supported")
 
     @override
     def suspend_events(self, ty: pwndbg.dbg_mod.EventType) -> None:

pwndbg/dbg/lldb/__init__.py

@@ -1986,7 +1986,7 @@ class LLDB(pwndbg.dbg_mod.Debugger):
         if ty not in self.event_handlers:
             # No one cares about this event type.
             return
-        if self.suspended_events[ty]:
+        if self.suspended_events[ty] or self.suspended_events[pwndbg.dbg_mod.EventType.SUSPEND_ALL]:
             # This event has been suspended.
             return
 
@@ -1994,9 +1994,9 @@ class LLDB(pwndbg.dbg_mod.Debugger):
             try:
                 handler()
             except Exception as e:
-                import pwndbg.exception
+                from pwndbg.exception import handle as pwndbg_exception
 
-                pwndbg.exception.handle()
+                pwndbg_exception()
                 raise e
 
     @override

pwndbg/gdblib/events.py

@@ -97,6 +97,7 @@ class StartEvent:
 
 
 gdb.events.start = StartEvent()
+gdb.events.suspend_all = object()
 
 
 def _is_safe_event_packet():
@@ -283,7 +284,7 @@ def connect(
 
     @wraps(func)
     def caller(*a: P.args, **kw: P.kwargs) -> None:
-        if paused[event_handler]:
+        if paused[event_handler] or paused[gdb.events.suspend_all]:
             return None
 
         if debug: