From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christian Borntraeger , Martin Schwidefsky 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 Message-Id: <20141003212939.898680677@linuxfoundation.org> In-Reply-To: <20141003212933.458851516@linuxfoundation.org> References: <20141003212933.458851516@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christian Borntraeger 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 Acked-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman --- 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