commit eb0bf929d5228ca0eb2758585f2e4e25aa20427e
author Heiko Carstens <heiko.carstens@de.ibm.com> Tue Oct 08 09:29:09 2013 +0200
committer Martin Schwidefsky <schwidefsky@de.ibm.com> Thu Oct 24 17:17:01 2013 +0200
tree 68b30c431a0418d31feaca8046a9deab86172b7e
parent 01997bbc924d63e6c4837c5d8dc190245bc473ec

s390/gup: handle zero nr_pages case correctly

If [__]get_user_pages_fast() gets called with nr_pages == 0, the current
code would walk the page tables and pin as many pages until the first
invalid pte (or the kernel crashed while writing struct page pointers to
the pages array).
So let's handle at least the nr_pages == 0 case correctly and exit early.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>