From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753187AbeDSS0I (ORCPT ); Thu, 19 Apr 2018 14:26:08 -0400 Received: from 8bytes.org ([81.169.241.247]:51022 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752937AbeDSS0H (ORCPT ); Thu, 19 Apr 2018 14:26:07 -0400 From: Joerg Roedel To: Thomas Gleixner , Ingo Molnar Cc: rjw@rjwysocki.net, pavel@ucw.cz, hpa@zytor.com, Michal Kubecek , Borislav Petkov , x86@kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Joerg Roedel Subject: [PATCH] x86/power/64: Fix page-table setup for temporary text mapping Date: Thu, 19 Apr 2018 20:26:00 +0200 Message-Id: <1524162360-26179-1-git-send-email-joro@8bytes.org> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joerg Roedel When we have a 4-level page-table there is no p4d, so we map the pud in the pgd. The old code before commit fb43d6cb91ef already did that. With the change from above commit we end up with an invalid page-table which causes undefined behavior. In one report it caused triple faults. Fix it by changing the p4d back to pud so that we have a correct page-table. Reported-by: Borislav Petkov Fixes: fb43d6cb91ef ('x86/mm: Do not auto-massage page protections') Tested-by: Michal Kubecek Tested-by: Borislav Petkov Signed-off-by: Joerg Roedel --- arch/x86/power/hibernate_64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/power/hibernate_64.c b/arch/x86/power/hibernate_64.c index 48b14b534897..ccf4a49bb065 100644 --- a/arch/x86/power/hibernate_64.c +++ b/arch/x86/power/hibernate_64.c @@ -98,7 +98,7 @@ static int set_up_temporary_text_mapping(pgd_t *pgd) set_pgd(pgd + pgd_index(restore_jump_address), new_pgd); } else { /* No p4d for 4-level paging: point the pgd to the pud page table */ - pgd_t new_pgd = __pgd(__pa(p4d) | pgprot_val(pgtable_prot)); + pgd_t new_pgd = __pgd(__pa(pud) | pgprot_val(pgtable_prot)); set_pgd(pgd + pgd_index(restore_jump_address), new_pgd); } -- 2.13.6