detect: free all tenant detect engines

Free all tenants registered in the master.

src/detect-engine.c

@@ -4492,14 +4492,10 @@ int DetectEngineAddToMaster(DetectEngineCtx *de_ctx)
     return r;
 }
 
-int DetectEngineMoveToFreeList(DetectEngineCtx *de_ctx)
+static int DetectEngineMoveToFreeListNoLock(DetectEngineMasterCtx *master, DetectEngineCtx *de_ctx)
 {
-    DetectEngineMasterCtx *master = &g_master_de_ctx;
-
-    SCMutexLock(&master->lock);
     DetectEngineCtx *instance = master->list;
     if (instance == NULL) {
-        SCMutexUnlock(&master->lock);
         return -1;
     }
 
@@ -4522,7 +4518,6 @@ int DetectEngineMoveToFreeList(DetectEngineCtx *de_ctx)
             instance = next;
         }
         if (instance == NULL) {
-            SCMutexUnlock(&master->lock);
             return -1;
         }
     }
@@ -4538,9 +4533,17 @@ int DetectEngineMoveToFreeList(DetectEngineCtx *de_ctx)
         master->free_list = instance;
     }
     SCLogDebug("detect engine %p moved to free list (%u refs)", de_ctx, de_ctx->ref_cnt);
+    return 0;
+}
 
+int DetectEngineMoveToFreeList(DetectEngineCtx *de_ctx)
+{
+    int ret = 0;
+    DetectEngineMasterCtx *master = &g_master_de_ctx;
+    SCMutexLock(&master->lock);
+    ret = DetectEngineMoveToFreeListNoLock(master, de_ctx);
     SCMutexUnlock(&master->lock);
-    return 0;
+    return ret;
 }
 
 void DetectEnginePruneFreeList(void)
@@ -4573,6 +4576,24 @@ void DetectEnginePruneFreeList(void)
     SCMutexUnlock(&master->lock);
 }
 
+void DetectEngineClearMaster(void)
+{
+    DetectEngineMasterCtx *master = &g_master_de_ctx;
+    SCMutexLock(&master->lock);
+
+    DetectEngineCtx *instance = master->list;
+    while (instance) {
+        DetectEngineCtx *next = instance->next;
+        DEBUG_VALIDATE_BUG_ON(instance->ref_cnt);
+        SCLogDebug("detect engine %p has %u ref(s)", instance, instance->ref_cnt);
+        instance->ref_cnt = 0;
+        DetectEngineMoveToFreeListNoLock(master, instance);
+        instance = next;
+    }
+    SCMutexUnlock(&master->lock);
+    DetectEnginePruneFreeList();
+}
+
 static int reloads = 0;
 
 /** \brief Reload the detection engine

src/detect-engine.h

@@ -114,6 +114,7 @@ DetectEngineCtx *DetectEngineGetCurrent(void);
 DetectEngineCtx *DetectEngineGetByTenantId(uint32_t tenant_id);
 void DetectEnginePruneFreeList(void);
 int DetectEngineMoveToFreeList(DetectEngineCtx *de_ctx);
+void DetectEngineClearMaster(void);
 DetectEngineCtx *DetectEngineReference(DetectEngineCtx *);
 void DetectEngineDeReference(DetectEngineCtx **de_ctx);
 int DetectEngineReload(const SCInstance *suri);

src/suricata.c

@@ -373,7 +373,7 @@ static void GlobalsDestroy(SCInstance *suri)
         DetectEngineMoveToFreeList(de_ctx);
         DetectEngineDeReference(&de_ctx);
     }
-    DetectEnginePruneFreeList();
+    DetectEngineClearMaster();
 
     AppLayerDeSetup();
     DatasetsSave();