🚀 go-pugleaf

I've got the gcc2.2.2+emx0.8e programming environment for OS/2 2.0.
Consider the following C-program:
   
    #include <stdio.h>
    #include <malloc.h>

    void main ()
    {
       char *buf = (char *) malloc (<size>);

       if (buf != NULL) printf ("memory allocated\n");
       else printf ("allocation failed\n");
       free (buf);
    } 

The behavior of the program:
If <size> gets too high (of course, <size> 
is in a valid integer range and >= 0) malloc doesn't return a 
NULL - pointer but the program turns in a core-dump
(gdb says that the program received signal 11, segmentation-fault)

Can YOU tell me how to solve the problem?
(I guess malloc gets in conflict with the
 memory protection of OS/2 2.0 but doesn't recognize 
 it as an error) 
Is there a way to use the virtual memory management
when allocating store on the heap?