s390/mm: correct allocate_pgste proc_handler callback
authorVasily Gorbik <gor@linux.ibm.com>
Sun, 24 Jun 2018 10:17:43 +0000 (12:17 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 4 Oct 2018 00:00:47 +0000 (17:00 -0700)
commit1117e411a46c4df5230b469dc4641dcc46274191
tree8cc0983a140f07fbf0aba15ff465407b4d754ef7
parentbc4ce060b30549bb56411e8443a45b55e276420f
s390/mm: correct allocate_pgste proc_handler callback

[ Upstream commit 5bedf8aa03c28cb8dc98bdd32a41b66d8f7d3eaa ]

Since proc_dointvec does not perform value range control,
proc_dointvec_minmax should be used to limit value range, which is
clearly intended here, as the internal representation of the value:

unsigned int alloc_pgste:1;

In fact it currently works, since we have

      mm->context.alloc_pgste = page_table_allocate_pgste || ...

... since commit 23fefe119ceb5 ("s390/kvm: avoid global config of vm.alloc_pgste=1")

Before that it was

       mm->context.alloc_pgste = page_table_allocate_pgste;

which was broken. That was introduced with commit 0b46e0a3ec0d7 ("s390/kvm:
remove delayed reallocation of page tables for KVM").

Fixes: 0b46e0a3ec0d7 ("s390/kvm: remove delayed reallocation of page tables for KVM")
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/s390/mm/pgalloc.c