CC2530: point and osal_mem_alloc usage in Z-Stack

Dear all,

I used cc2530 + Z-Stack 3.0. The following code cannot assign "6" to "g_ptr". Anyone knows what is the problem? Thank you much.

int *g_ptr;   //global pointer 

void test( int *p )
{

p = osal_mem_alloc(sizeof(int));

*p = 6;

}
void main(void) // I used main() to simplify my description. This should be a init function of a task e.g. zclSampleSw_Init()
{

test(g_ptr);

}

Best regards,

Barry