better handling of writeBlockSize greater than samples/slot

fix the case when writeBlockSize is greater than samples/slot
by sending samples from the same buffer instead of out-of-bounds memory read

executables/nr-ue.c

@@ -483,11 +483,23 @@ static void RU_write(nr_rxtx_thread_data_t *rxtxD, bool sl_tx_action)
     }
   }
 
-  int tmp = openair0_write_reorder(&UE->rfdevice, proc->timestamp_tx, txp, rxtxD->writeBlockSize, fp->nb_antennas_tx, flags);
-  AssertFatal(tmp == rxtxD->writeBlockSize, "");
+  openair0_timestamp writeTimestamp = proc->timestamp_tx;
+  int writeBlockSize = rxtxD->writeBlockSize;
+  if ( writeBlockSize > fp->get_samples_per_slot(proc->nr_slot_tx, fp)) {
+    // if writeBlockSize gets longer that slot size, fill with dummy
+    const int dummyBlockSize = writeBlockSize - fp->get_samples_per_slot(proc->nr_slot_tx, fp);
+    int tmp = openair0_write_reorder(&UE->rfdevice, writeTimestamp, txp, dummyBlockSize, fp->nb_antennas_tx, flags);
+    AssertFatal(tmp == dummyBlockSize, "");
+
+    writeTimestamp += dummyBlockSize;
+    writeBlockSize -= dummyBlockSize;
+  }
+
+  int tmp = openair0_write_reorder(&UE->rfdevice, writeTimestamp, txp, writeBlockSize, fp->nb_antennas_tx, flags);
+  AssertFatal(tmp == writeBlockSize, "");
 
   for (int i = 0; i < fp->nb_antennas_tx; i++)
-    memset(txp[i], 0, rxtxD->writeBlockSize);
+    memset(txp[i], 0, writeBlockSize);
 }
 
 void processSlotTX(void *arg)