Christian Borntraeger 3d42ca46f4 s390/mm: fix CMMA vs KSM vs others
commit a8f60d1fadf7b8b54449fcc9d6b15248917478ba upstream.

On heavy paging with KSM I see guest data corruption. Turns out that
KSM will add pages to its tree, where the mapping return true for
pte_unused (or might become as such later).  KSM will unmap such pages
and reinstantiate with different attributes (e.g. write protected or
special, e.g. in replace_page or write_protect_page)). This uncovered
a bug in our pagetable handling: We must remove the unused flag as
soon as an entry becomes present again.

Signed-of-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-27 09:10:38 +02:00
..
2016-10-30 10:13:55 +01:00
2017-04-12 12:41:13 +02:00
2017-04-27 09:10:38 +02:00
2016-10-19 08:39:47 -07:00