Commit 52446fb9 authored by Christian Borntraeger's avatar Christian Borntraeger Committed by Greg Kroah-Hartman

KVM: s390/mm: Fix guest storage key corruption in ptep_set_access_flags

commit 1951497d upstream.

commit 0944fe3f ("s390/mm: implement software referenced bits")
triggered another paging/storage key corruption. There is an
unhandled invalid->valid pte change where we have to set the real
storage key from the pgste.
When doing paging a guest page might be swapcache or swap and when
faulted in it might be read-only and due to a parallel scan old.
An do_wp_page will make it writeable and young. Due to software
reference tracking this page was invalid and now becomes valid.
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 379c54e8
...@@ -1319,6 +1319,7 @@ static inline int ptep_set_access_flags(struct vm_area_struct *vma, ...@@ -1319,6 +1319,7 @@ static inline int ptep_set_access_flags(struct vm_area_struct *vma,
ptep_flush_direct(vma->vm_mm, address, ptep); ptep_flush_direct(vma->vm_mm, address, ptep);
if (mm_has_pgste(vma->vm_mm)) { if (mm_has_pgste(vma->vm_mm)) {
pgste_set_key(ptep, pgste, entry, vma->vm_mm);
pgste = pgste_set_pte(ptep, pgste, entry); pgste = pgste_set_pte(ptep, pgste, entry);
pgste_set_unlock(ptep, pgste); pgste_set_unlock(ptep, pgste);
} else } else
......
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