fix: repair RC.mac memory allocation

- there can be a race between the FlexRAN agent reading the RC.mac and its
  allocation in main.c
- In order to circumvent this, change the allocation by allocating
  everything "into" a local variable
- finally "make it visible" by storing  the pointer in RC.mac

openair2/LAYER2/MAC/main.c

@@ -46,83 +46,56 @@
 
 extern RAN_CONTEXT_t RC;
 
-
 void mac_top_init_eNB(void)
 {
-
   module_id_t i, j;
   int list_el;
   UE_list_t *UE_list;
   slice_info_t *sli;
-    eNB_MAC_INST *mac;
+  eNB_MAC_INST **mac;
 
   LOG_I(MAC, "[MAIN] Init function start:nb_macrlc_inst=%d\n",
         RC.nb_macrlc_inst);
 
-    if (RC.nb_macrlc_inst > 0) {
-      if (RC.mac == NULL){
-		RC.mac =
-			(eNB_MAC_INST **) malloc16(RC.nb_macrlc_inst *
-						   sizeof(eNB_MAC_INST *));
-                bzero(RC.mac, RC.nb_macrlc_inst * sizeof(eNB_MAC_INST *));
+  if (RC.nb_macrlc_inst <= 0) {
+    RC.mac = NULL;
+    return;
   }
-	AssertFatal(RC.mac != NULL,
+
+  mac = malloc16(RC.nb_macrlc_inst * sizeof(eNB_MAC_INST *));
+  AssertFatal(mac != NULL,
               "can't ALLOCATE %zu Bytes for %d eNB_MAC_INST with size %zu \n",
               RC.nb_macrlc_inst * sizeof(eNB_MAC_INST *),
               RC.nb_macrlc_inst, sizeof(eNB_MAC_INST));
   for (i = 0; i < RC.nb_macrlc_inst; i++) {
-            if (RC.mac[i] == NULL) {
-                RC.mac[i] = (eNB_MAC_INST *) malloc16(sizeof(eNB_MAC_INST));
-                AssertFatal(RC.mac[i] != NULL,
+    mac[i] = malloc16(sizeof(eNB_MAC_INST));
+    AssertFatal(mac[i] != NULL,
                 "can't ALLOCATE %zu Bytes for %d eNB_MAC_INST with size %zu \n",
                 RC.nb_macrlc_inst * sizeof(eNB_MAC_INST *),
                 RC.nb_macrlc_inst, sizeof(eNB_MAC_INST));
     LOG_D(MAC,
           "[MAIN] ALLOCATE %zu Bytes for %d eNB_MAC_INST @ %p\n",
-                      sizeof(eNB_MAC_INST), RC.nb_macrlc_inst, RC.mac);
-                bzero(RC.mac[i], sizeof(eNB_MAC_INST));
-            }
-	    RC.mac[i]->Mod_id = i;
+          sizeof(eNB_MAC_INST), RC.nb_macrlc_inst, mac);
+    bzero(mac[i], sizeof(eNB_MAC_INST));
+    mac[i]->Mod_id = i;
     for (j = 0; j < MAX_NUM_CCs; j++) {
-		RC.mac[i]->DL_req[j].dl_config_request_body.
-		    dl_config_pdu_list = RC.mac[i]->dl_config_pdu_list[j];
-		RC.mac[i]->UL_req[j].ul_config_request_body.
-		    ul_config_pdu_list = RC.mac[i]->ul_config_pdu_list[j];
+      mac[i]->DL_req[j].dl_config_request_body.dl_config_pdu_list =
+          mac[i]->dl_config_pdu_list[j];
+      mac[i]->UL_req[j].ul_config_request_body.ul_config_pdu_list =
+          mac[i]->ul_config_pdu_list[j];
       for (int k = 0; k < 10; k++)
-		    RC.mac[i]->UL_req_tmp[j][k].
-			ul_config_request_body.ul_config_pdu_list =
-			RC.mac[i]->ul_config_pdu_list_tmp[j][k];
-		for(int sf=0;sf<10;sf++){
-		    RC.mac[i]->HI_DCI0_req[j][sf].hi_dci0_request_body.hi_dci0_pdu_list =RC.mac[i]->hi_dci0_pdu_list[j][sf];
-		}
-
-		RC.mac[i]->TX_req[j].tx_request_body.tx_pdu_list =
-		    RC.mac[i]->tx_request_pdu[j];
-		RC.mac[i]->ul_handle = 0;
-	    }
-	}
-
-	AssertFatal(rlc_module_init() == 0,
-		    "Could not initialize RLC layer\n");
-
-	// These should be out of here later
-	pdcp_layer_init();
-
-	rrc_init_global_param();
-
-    } else {
-	RC.mac = NULL;
+        mac[i]->UL_req_tmp[j][k].ul_config_request_body.ul_config_pdu_list =
+            mac[i]->ul_config_pdu_list_tmp[j][k];
+      for(int sf=0;sf<10;sf++)
+        mac[i]->HI_DCI0_req[j][sf].hi_dci0_request_body.hi_dci0_pdu_list =
+            mac[i]->hi_dci0_pdu_list[j][sf];
+      mac[i]->TX_req[j].tx_request_body.tx_pdu_list = mac[i]->tx_request_pdu[j];
+      mac[i]->ul_handle = 0;
     }
 
-    // Initialize Linked-List for Active UEs and slice configuration
-    for (i = 0; i < RC.nb_macrlc_inst; i++) {
-	mac = RC.mac[i];
-
-
-	mac->if_inst = IF_Module_init(i);
-
-	UE_list = &mac->UE_list;
+    mac[i]->if_inst = IF_Module_init(i);
 
+    UE_list = &mac[i]->UE_list;
     UE_list->num_UEs = 0;
     UE_list->head = -1;
     UE_list->head_ul = -1;
@@ -132,12 +105,10 @@ void mac_top_init_eNB(void)
 	    UE_list->next[list_el] = list_el + 1;
 	    UE_list->next_ul[list_el] = list_el + 1;
     }
-
     UE_list->next[list_el] = -1;
     UE_list->next_ul[list_el] = -1;
 
-        sli = &mac->slice_info;
-
+    sli = &mac[i]->slice_info;
     sli->intraslice_share_active = 1;
     sli->interslice_share_active = 1;
 
@@ -162,6 +133,15 @@ void mac_top_init_eNB(void)
     AssertFatal(sli->ul[0].sched_cb, "ULSCH scheduler callback is NULL\n");
   }
 
+  RC.mac = mac;
+
+  AssertFatal(rlc_module_init() == 0,
+      "Could not initialize RLC layer\n");
+
+  // These should be out of here later
+  pdcp_layer_init();
+
+  rrc_init_global_param();
 }
 
 void mac_init_cell_params(int Mod_idP, int CC_idP)