From d878efce73fe86db34ddb2013260adf571a701a7 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Wed, 8 Aug 2018 13:16:40 +0200 Subject: x86/mm/pti: Move user W+X check into pti_finalize() The user page-table gets the updated kernel mappings in pti_finalize(), which runs after the RO+X permissions got applied to the kernel page-table in mark_readonly(). But with CONFIG_DEBUG_WX enabled, the user page-table is already checked in mark_readonly() for insecure mappings. This causes false-positive warnings, because the user page-table did not get the updated mappings yet. Move the W+X check for the user page-table into pti_finalize() after it updated all required mappings. [ tglx: Folded !NX supported fix ] Signed-off-by: Joerg Roedel Signed-off-by: Thomas Gleixner Cc: "H . Peter Anvin" Cc: linux-mm@kvack.org Cc: Linus Torvalds Cc: Andy Lutomirski Cc: Dave Hansen Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Peter Zijlstra Cc: Borislav Petkov Cc: Jiri Kosina Cc: Boris Ostrovsky Cc: Brian Gerst Cc: David Laight Cc: Denys Vlasenko Cc: Eduardo Valentin Cc: Greg KH Cc: Will Deacon Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: Andrea Arcangeli Cc: Waiman Long Cc: Pavel Machek Cc: "David H . Gutteridge" Cc: joro@8bytes.org Link: https://lkml.kernel.org/r/1533727000-9172-1-git-send-email-joro@8bytes.org --- arch/x86/include/asm/pgtable.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'arch/x86/include/asm') diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index e39088cb59ab..a1cb3339da8d 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -30,11 +30,14 @@ int __init __early_make_pgtable(unsigned long address, pmdval_t pmd); void ptdump_walk_pgd_level(struct seq_file *m, pgd_t *pgd); void ptdump_walk_pgd_level_debugfs(struct seq_file *m, pgd_t *pgd, bool user); void ptdump_walk_pgd_level_checkwx(void); +void ptdump_walk_user_pgd_level_checkwx(void); #ifdef CONFIG_DEBUG_WX -#define debug_checkwx() ptdump_walk_pgd_level_checkwx() +#define debug_checkwx() ptdump_walk_pgd_level_checkwx() +#define debug_checkwx_user() ptdump_walk_user_pgd_level_checkwx() #else -#define debug_checkwx() do { } while (0) +#define debug_checkwx() do { } while (0) +#define debug_checkwx_user() do { } while (0) #endif /* -- cgit v1.2.3