Re-order syscallbuf unmapping and stashed signal injection

Keno · Keno · commit 758ad30a3edf · 2024-09-21T01:00:49.000Z
Fixes assertion in rr-debugger#3831. Using AutoRemoteSyscalls is not permitted after the signal injection check, since it could cause additional signals to be stashed.
diff --git a/src/RecordSession.cc b/src/RecordSession.cc
@@ -936,7 +936,6 @@ void RecordSession::task_continue(const StepState& step_state) {
       }
     }
   }
-  t->unmap_dead_syscallbufs_if_required();
   t->resume_execution(resume, RESUME_NONBLOCKING, ticks_request);
 }
 
@@ -2709,6 +2708,7 @@ RecordSession::RecordResult RecordSession::record_step() {
   }
 
   t->verify_signal_states();
+  t->unmap_dead_syscallbufs_if_required();
 
   // We try to inject a signal if there's one pending; otherwise we continue
   // task execution.

Original file line number	Diff line number	Diff line change
`@@ -936,7 +936,6 @@ void RecordSession::task_continue(const StepState& step_state) {`
`936`	`936`	`}`
`937`	`937`	`}`
`938`	`938`	`}`
`939`		`- t->unmap_dead_syscallbufs_if_required();`
`940`	`939`	`t->resume_execution(resume, RESUME_NONBLOCKING, ticks_request);`
`941`	`940`	`}`
`942`	`941`
`@@ -2709,6 +2708,7 @@ RecordSession::RecordResult RecordSession::record_step() {`
`2709`	`2708`	`}`
`2710`	`2709`
`2711`	`2710`	`t->verify_signal_states();`
	`2711`	`+ t->unmap_dead_syscallbufs_if_required();`
`2712`	`2712`
`2713`	`2713`	`// We try to inject a signal if there's one pending; otherwise we continue`
`2714`	`2714`	`// task execution.`