2017-04-20 07:06:56

by Martin Schwidefsky

[permalink] [raw]
Subject: [GIT PULL] s390 patches for 4.11-rc8/final

Hi Linus,

please pull from the 'for-linus' branch of

git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git for-linus

to receive the following updates:

There is one more fix I would like to see in 4.11. The combination
of KVM, CMMA and heavy paging can cause data corruption, the fix
is to clear the _PAGE_UNUSED bit in set_pte_at.

Christian Borntraeger (1):
s390/mm: fix CMMA vs KSM vs others

arch/s390/include/asm/pgtable.h | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 93e37b1..ecec682 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1051,6 +1051,8 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
{
if (!MACHINE_HAS_NX)
pte_val(entry) &= ~_PAGE_NOEXEC;
+ if (pte_present(entry))
+ pte_val(entry) &= ~_PAGE_UNUSED;
if (mm_has_pgste(mm))
ptep_set_pte_at(mm, addr, ptep, entry);
else