Correct nr_clear_ra_proc() for SA+NSA case, fix memory leak

In NSA, the RA process contains the RNTI of the UE to add. The previous
implementation would not remove the RNTI in NSA/for CFRA, which is
unclear (why should it stay? RA is over). Also, we did not clear all
contents, which masked a bug, as we were reusing an RA process for a
subsequent attach, leading to a segfault on reattach. That is fixed in
this commit.

Also, we were using the RA structure after having cleared it in
_nr_rx_sdu(), which semantically makes no sense.

To harmonize handling of the preambles: completely reset the RA
processes inside nr_clear_ra_proc(). For SA, also add the initialization
of allowed preambles.

Finally, this commit fixes a memory leak: we always (also in SA) fill a
list of preambles in a dynamically allocated preamble list. Since the
total list is only up to 64 preambles of 1B each, put it directly into
the struct instead of dynamically allocating it.

openair2/LAYER2/NR_MAC_gNB/config.c

@@ -603,7 +603,6 @@ void nr_mac_config_scc(gNB_MAC_INST *nrmac, NR_ServingCellConfigCommon_t *scc, c
   DevAssert(nrmac != NULL);
   DevAssert(scc != NULL);
   DevAssert(config != NULL);
-  //NR_SCHED_LOCK(&nrmac->sched_lock);
 
   AssertFatal(scc->ssb_PositionsInBurst->present > 0 && scc->ssb_PositionsInBurst->present < 4,
               "SSB Bitmap type %d is not valid\n",
@@ -668,19 +667,13 @@ void nr_mac_config_scc(gNB_MAC_INST *nrmac, NR_ServingCellConfigCommon_t *scc, c
     nrmac->pre_processor_ul = nr_init_fr1_ulsch_preprocessor(0);
   }
 
-  if (get_softmodem_params()->sa > 0) {
-    NR_COMMON_channels_t *cc = &nrmac->common_channels[0];
-    for (int n = 0; n < NR_NB_RA_PROC_MAX; n++) {
-      NR_RA_t *ra = &cc->ra[n];
-      ra->cfra = false;
-      ra->rnti = 0;
-      ra->preambles.num_preambles = MAX_NUM_NR_PRACH_PREAMBLES;
-      ra->preambles.preamble_list = malloc(MAX_NUM_NR_PRACH_PREAMBLES * sizeof(*ra->preambles.preamble_list));
-      for (int i = 0; i < MAX_NUM_NR_PRACH_PREAMBLES; i++)
-        ra->preambles.preamble_list[i] = i;
-    }
+  NR_COMMON_channels_t *cc = &nrmac->common_channels[0];
+  NR_SCHED_LOCK(&nrmac->sched_lock);
+  for (int n = 0; n < NR_NB_RA_PROC_MAX; n++) {
+    NR_RA_t *ra = &cc->ra[n];
+    nr_clear_ra_proc(ra);
   }
-  //NR_SCHED_UNLOCK(&nrmac->sched_lock);
+  NR_SCHED_UNLOCK(&nrmac->sched_lock);
 }
 
 void nr_mac_configure_sib1(gNB_MAC_INST *nrmac, const f1ap_plmn_t *plmn, uint64_t cellID, int tac)
@@ -749,7 +742,6 @@ bool nr_mac_prepare_ra_ue(gNB_MAC_INST *nrmac, uint32_t rnti, NR_CellGroupConfig
   struct NR_CFRA *cfra = CellGroup->spCellConfig->reconfigurationWithSync->rach_ConfigDedicated->choice.uplink->cfra;
   uint8_t num_preamble = cfra->resources.choice.ssb->ssb_ResourceList.list.count;
   ra->preambles.num_preambles = num_preamble;
-  ra->preambles.preamble_list = calloc(ra->preambles.num_preambles, sizeof(*ra->preambles.preamble_list));
   for (int i = 0; i < cc->num_active_ssb; i++) {
     for (int j = 0; j < num_preamble; j++) {
       if (cc->ssb_index[i] == cfra->resources.choice.ssb->ssb_ResourceList.list.array[j]->ssb) {

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_RA.c

@@ -2017,11 +2017,12 @@ void nr_clear_ra_proc(NR_RA_t *ra)
 {
   /* we assume that this function is mutex-protected from outside */
   NR_SCHED_ENSURE_LOCKED(&RC.nrmac[0]->sched_lock);
+  memset(ra, 0, sizeof(*ra));
   ra->ra_state = nrRA_gNB_IDLE;
-  ra->timing_offset = 0;
-  ra->msg3_round = 0;
-  if(ra->cfra == false) {
-    ra->rnti = 0;
+  if (get_softmodem_params()->sa) { // in SA, prefill with allowed preambles
+    ra->preambles.num_preambles = MAX_NUM_NR_PRACH_PREAMBLES;
+    for (int i = 0; i < MAX_NUM_NR_PRACH_PREAMBLES; i++)
+      ra->preambles.preamble_list[i] = i;
   }
 }
 

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c

@@ -851,8 +851,8 @@ static void _nr_rx_sdu(const module_id_t gnb_mod_idP,
         nr_mac_reset_ul_failure(UE_scheduling_control);
         reset_dl_harq_list(UE_scheduling_control);
         reset_ul_harq_list(UE_scheduling_control);
-        nr_clear_ra_proc(ra);
         process_addmod_bearers_cellGroupConfig(&UE->UE_sched_ctrl, ra->CellGroup->rlc_BearerToAddModList);
+        nr_clear_ra_proc(ra);
       } else {
         LOG_A(NR_MAC, "[RAPROC] RA-Msg3 received (sdu_lenP %d)\n", sdu_lenP);
         LOG_D(NR_MAC, "[RAPROC] Received Msg3:\n");

openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h

@@ -159,7 +159,7 @@ typedef struct nr_mac_config_t {
 
 typedef struct NR_preamble_ue {
   uint8_t num_preambles;
-  uint8_t *preamble_list;
+  uint8_t preamble_list[MAX_NUM_NR_PRACH_PREAMBLES];
 } NR_preamble_ue_t;
 
 typedef struct NR_sched_pdcch {