move_addr_to_kernel() and memory considerations!!!

["pradeep singh" <2500.pradeep@xxxxxxxxx>]

Hi,
here is the code snippet to copy a socket address to kernel address space from user address space.

int move_addr_to_kernel(void __user *uaddr, int ulen, void *kaddr)
{
	    if(ulen<0||ulen>MAX_SOCK_ADDR)
		       return -EINVAL;
	    if(ulen==0)
		      return 0;
	    if(copy_from_user(kaddr,uaddr,ulen))
		        return -EFAULT;
	        return audit_sockaddr(ulen, kaddr);
}

Ok, here is the query - 
What if the user address is actually mapped on to physical memory > 1 GB. 
I cannot figure out then how the socket address space will be copied without involving any temporary kernel mappings?And i also do not see any code involving creation of  the temporary mappings in this case?  
 
Any help?What am i missing here?  

Thank you
~psr

-- 
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