MDEV-22950 followup

Deadlock in DbugParse, on Linux. In 10.1, DBUG recursive mutex was improperly implemented. CODE_STATE::locked counter was never updated. Copy the code around LockMutex/UnlockMutex from 10.2
MariaDB · Jun 25, 2020 · 7ee6a3a · 7ee6a3a
1 parent f183843
commit 7ee6a3a
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/dbug/dbug.c b/dbug/dbug.c
@@ -330,10 +330,13 @@ static void LockMutex(CODE_STATE *cs)
 {
   if (!cs->locked)
     pthread_mutex_lock(&THR_LOCK_dbug);
+  cs->locked++;
 }
 static void UnlockMutex(CODE_STATE *cs)
 {
-  if (!cs->locked)
+  --cs->locked;
+  assert(cs->locked >= 0);
+  if (cs->locked == 0)
     pthread_mutex_unlock(&THR_LOCK_dbug);
 }
 static void LockIfInitSettings(CODE_STATE *cs)