erts: Must have main lock when flushing trace messages

If we don't have the main lock, multiple threads may come in and
do the flush at the same time which will lead to all kinds of
strang problems.

1 files changed, 9 insertions, 9 deletions

diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index fc2b34e70f..0ff9484daf 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -11768,9 +11768,11 @@ flush_dirty_trace_messages(void *vpid)
     erts_free(ERTS_ALC_T_DIRTY_SL, vpid);
 #endif
 
-    proc = erts_proc_lookup(pid);
-    if (proc)
-	(void) erts_flush_trace_messages(proc, 0);
+    proc = erts_pid2proc_opt(NULL, 0, pid, ERTS_PROC_LOCK_MAIN, 0);
+    if (proc) {
+	(void) erts_flush_trace_messages(proc, ERTS_PROC_LOCK_MAIN);
+        erts_smp_proc_unlock(proc, ERTS_PROC_LOCK_MAIN);
+    }
 }
 
 #endif /* ERTS_DIRTY_SCHEDULERS */
@@ -14102,8 +14104,11 @@ erts_continue_exit_process(Process *p)
 								 have none here */
     }
 
+    erts_smp_proc_lock(p, ERTS_PROC_LOCK_MAIN);
+    ERTS_SMP_CHK_HAVE_ONLY_MAIN_PROC_LOCK(p);
+
 #ifdef ERTS_SMP
-    erts_flush_trace_messages(p, 0);
+    erts_flush_trace_messages(p, ERTS_PROC_LOCK_MAIN);
 #endif
 
     ERTS_TRACER_CLEAR(&ERTS_TRACER(p));
@@ -14111,11 +14116,6 @@ erts_continue_exit_process(Process *p)
     if (!delay_del_proc)
 	delete_process(p);
 
-#ifdef ERTS_SMP
-    erts_smp_proc_lock(p, ERTS_PROC_LOCK_MAIN);
-    ERTS_SMP_CHK_HAVE_ONLY_MAIN_PROC_LOCK(p);
-#endif
-
     return;
 
  yield: