From b7f737d99edd7dfc04e80ca9fcd23fc8276b4dca Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Thu, 19 Apr 2018 20:26:00 +0200 Subject: [PATCH] x86/power/64: Fix page-table setup for temporary text mapping On a system with 4-level page-tables there is no p4d, so the pud in the pgd should be mapped. The old code before commit 7d416b46e1c4 already did that. The change from above commit causes an invalid page-table which causes undefined behavior. In one report it caused triple faults. Fix it by changing the p4d back to pud. Fixes: 7d416b46e1c4 ('x86/mm: Do not auto-massage page protections') Reported-by: Borislav Petkov Signed-off-by: Joerg Roedel Signed-off-by: Thomas Gleixner Tested-by: Michal Kubecek Tested-by: Borislav Petkov Cc: linux-pm@vger.kernel.org Cc: rjw@rjwysocki.net Cc: pavel@ucw.cz Cc: hpa@zytor.com Cc: Dave Hansen Link: https://lkml.kernel.org/r/1524162360-26179-1-git-send-email-joro@8bytes.org --- 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 48b14b534897e..ccf4a49bb065e 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); } -- 2.39.5