Bugfix for overflow when allocating memory.

Codes/MaM/distribution_methods/Distributed_CommDist.c

@@ -76,10 +76,10 @@ void sync_communication(void *send, void **recv, int qty, MPI_Datatype datatype,
   prepare_redistribution(qty, datatype, numP, numO, is_children_group, recv, &s_counts, &r_counts);
 
   /* PERFORM COMMUNICATION */
-    switch(mall_conf->red_method) {
+  switch (mall_conf->red_method) {
   case MAM_RED_RMA_LOCKALL:
   case MAM_RED_RMA_LOCK:
-        if(is_children_group) {
+    if (is_children_group) {
       dist_data.tamBl = 0;
     } else {
       get_block_dist(qty, mall->myId, numO, &dist_data);
@@ -524,12 +524,13 @@ void prepare_redistribution(int qty, MPI_Datatype datatype, int numP, int numO,
   int array_size = numO;
   int offset_ids = 0;
   int datasize;
+  size_t total_bytes;
   struct Dist_data dist_data;
 
   if(mall_conf->spawn_method == MAM_SPAWN_BASELINE) {
     offset_ids =  MAM_Contains_strat(MAM_SPAWN_STRATEGIES, MAM_STRAT_SPAWN_INTERCOMM, NULL) ? 
 	    0 : numP;
-  } else {
+  } else { // Merge method
     array_size = numP > numO ? numP : numO;
   }
 
@@ -543,7 +544,8 @@ void prepare_redistribution(int qty, MPI_Datatype datatype, int numP, int numO,
     
     // Obtener distribución para este hijo
     get_block_dist(qty, mall->myId, numP, &dist_data);
-    *recv = malloc(dist_data.tamBl * datasize);
+    total_bytes = ((size_t) dist_data.tamBl) * ((size_t) datasize);
+    *recv = malloc(total_bytes);
 
     #if MAM_DEBUG >= 4
       get_block_dist(qty, mall->myId, numP, &dist_data);
@@ -559,7 +561,8 @@ void prepare_redistribution(int qty, MPI_Datatype datatype, int numP, int numO,
       prepare_comm_alltoall(mall->myId, numO, numP, qty, offset_ids, r_counts);
       // Obtener distribución para este hijo y reservar vector de recibo
       get_block_dist(qty, mall->myId, numO, &dist_data);
-      *recv = malloc(dist_data.tamBl * datasize);
+      total_bytes = ((size_t) dist_data.tamBl) * ((size_t) datasize);
+      *recv = malloc(total_bytes);
       #if MAM_DEBUG >= 4
         print_counts(dist_data, r_counts->counts, r_counts->displs, array_size, 0, "Sources&Targets Recv");
       #endif