Hello Community!

I would like to know your opinion this code, i want to display a pointer with diag.
Code:
typedef struct MY_DEF {
  int my_number;
} MY_DEF;
MY_DEF* my_type;
my_type = malloc(sizeof(MY_DEF));
diag(str_printf(str, "nPointer:%d",(long)my_type));

Do you see any problem with this code?