1 files changed, 38 insertions, 2 deletions
diff --git a/debug/risc-v-gsp-rm-vm/harness/control_discovery.py b/debug/risc-v-gsp-rm-vm/harness/control_discovery.py
index eecf082..b44636a 100644
--- a/debug/risc-v-gsp-rm-vm/harness/control_discovery.py
+++ b/debug/risc-v-gsp-rm-vm/harness/control_discovery.py
@@ -115,6 +115,10 @@ SETTLE_MARKER = "SELFTEST DONE"
 SETTLE_SLICE = 0.02
 RUN_SLICE = 0.02
 TRAP_GRACE = 0.05
+#: Bound on instruction-driven single-steps used to retire a dispatcher's
+#: store sequence after the wall-clock observation window expires mid-epilogue
+#: (keeps findings byte-reproducible instead of timer-dependent).
+EPILOGUE_MAX_STEPS = 64
 #: gdb signals that carry a hazard (illegal, trap, bus, segv); SIGINT from the
 #: budget interrupt is wall-clock dependent and must never enter a finding.
 HAZARD_SIGNALS = (4, 5, 7, 11)
@@ -662,12 +666,16 @@ class ProbeRunner:
 
         Completion is a ``result`` store (the dispatcher writes it after every
         handler) or a trap/grace for ids that never return to the dispatcher.
+        The wall-clock loop is the budget for the no-progress/hung cases; when
+        a dispatch has been seen the store sequence is then retired with
+        bounded single-steps so the recorded effects cannot depend on where
+        the timer happened to expire.
         """
         deadline = time.monotonic() + self.options.timeout
         handler_seen_at: float | None = None
         while time.monotonic() < deadline:
             if not session.target.alive():
-                return
+                break
             remaining = max(0.005, min(RUN_SLICE, deadline - time.monotonic()))
             session.run(duration=remaining, max_stops=64)
             if handlers and handler_seen_at is None:
@@ -675,9 +683,37 @@ class ProbeRunner:
             result_written = any(hit.get("field") == "result" for hit in observer.hits)
             trapped = any(sig.get("signal") == 5 for sig in signals) or session.pc < 0x100
             if dispatches and (result_written or trapped):
-                return
+                break
             if handler_seen_at is not None and time.monotonic() - handler_seen_at >= TRAP_GRACE:
                 # Slow/hung handler: one grace window after the entry, then stop.
+                break
+        self._retire_dispatch(session, dispatches, signals, observer)
+
+    def _retire_dispatch(self, session, dispatches, signals, observer) -> None:
+        """Finish a dispatched command's store sequence with single-steps.
+
+        The demo dispatcher stores ``result``, ``last_rpc`` and finally
+        ``rpc_count``; a wall-clock observation window can expire between
+        those stores, which made findings timing-dependent.  Once a dispatch
+        has been seen, step (bounded and instruction-driven) until the final
+        watched store retires, a trap is seen, or the budget is exhausted.
+        """
+        if not dispatches or not any(watched.name == "rpc_count" for watched in observer.watched):
+            return
+        if any(hit.get("field") == "rpc_count" for hit in observer.hits):
+            return
+        if any(sig.get("signal") == 5 for sig in signals):
+            return
+        for _ in range(EPILOGUE_MAX_STEPS):
+            if not session.target.alive():
+                return
+            try:
+                session.step()
+            except (RspTimeout, GreenEyeError):
+                return
+            if any(hit.get("field") == "rpc_count" for hit in observer.hits):
+                return
+            if any(sig.get("signal") == 5 for sig in signals):
                 return
 
     def _keep(self, outcome: str) -> bool: