| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.16 212/357] KVM: s390/mm: Fix guest storage key corruption in ptep_set_access_flags | Date | Fri, 3 Oct 2014 14:29:58 -0700 |
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3.16-stable review patch. If anyone has any objections, please let me know.
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From: Christian Borntraeger <borntraeger@de.ibm.com>
commit 1951497d90d6754201af3e65241a06f9ef6755cd upstream.
commit 0944fe3f4a32 ("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: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- arch/s390/include/asm/pgtable.h | 1 + 1 file changed, 1 insertion(+)
--- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -1319,6 +1319,7 @@ static inline int ptep_set_access_flags( ptep_flush_direct(vma->vm_mm, address, ptep); if (mm_has_pgste(vma->vm_mm)) { + pgste_set_key(ptep, pgste, entry, vma->vm_mm); pgste = pgste_set_pte(ptep, pgste, entry); pgste_set_unlock(ptep, pgste); } else
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