copy_to_user to a kmapped address

[Jeff Dike <jdike@karaya.com>]

Is this (in file_read_actor) bogus or am I missing something?

1621            kaddr = kmap(page);
1622            left = __copy_to_user(desc->buf, kaddr + offset, size);
1623            kunmap(page);

It seems to me that copy_to_user should be able to assume that the destination
address is a user address.

This is biting me because I'm moving the UML kernel into a separate address
space, so there's no way, in general, to tell the difference between a kernel
address and a userspace address.

				Jeff