if(IS_ERR(phys)) phys = (void *) -1;  
static unsigned long maybe_map(unsigned long virt, int is_write){	pte_t pte;	int err;	void *phys = um_virt_to_phys(current, virt, &pte);	int dummy_code;	if(IS_ERR(phys) || (is_write && !pte_write(pte))){		err = handle_page_fault(virt, 0, is_write, 1, &dummy_code);		if(err)			return(0);		phys = um_virt_to_phys(current, virt, NULL);	}	return((unsigned long) phys);}
4520	/local/tlutelli/issta_data/temp/c/2005_temp/2005/4520/2d58cc9a437f3833d242e9d1617ec9b4044e26f3/uaccess.c/clean/arch/um/kernel/skas/uaccess.c