From 1951497d90d6754201af3e65241a06f9ef6755cd Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Thu, 28 Aug 2014 23:44:57 +0200 Subject: [PATCH] KVM: s390/mm: Fix guest storage key corruption in ptep_set_access_flags 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 Acked-by: Martin Schwidefsky Cc: stable@vger.kernel.org # v3.12+ --- arch/s390/include/asm/pgtable.h | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index 32686e891313..5efb2fe186e7 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -1331,6 +1331,7 @@ static inline int ptep_set_access_flags(struct vm_area_struct *vma, 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 -- 2.20.1