Commit-ID: a13c600e15de44ccf03df28d3311ef3cb754ed9b Gitweb: https://git.kernel.org/tip/a13c600e15de44ccf03df28d3311ef3cb754ed9b Author: Joerg Roedel <[email protected]> AuthorDate: Wed, 8 Aug 2018 13:16:40 +0200 Committer: Thomas Gleixner <[email protected]> CommitDate: Thu, 9 Aug 2018 20:42:07 +0200
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. Signed-off-by: Joerg Roedel <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: "H . Peter Anvin" <[email protected]> Cc: [email protected] Cc: Linus Torvalds <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Juergen Gross <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Jiri Kosina <[email protected]> Cc: Boris Ostrovsky <[email protected]> Cc: Brian Gerst <[email protected]> Cc: David Laight <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: Eduardo Valentin <[email protected]> Cc: Greg KH <[email protected]> Cc: Will Deacon <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: Andrea Arcangeli <[email protected]> Cc: Waiman Long <[email protected]> Cc: Pavel Machek <[email protected]> Cc: "David H . Gutteridge" <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] --- arch/x86/include/asm/pgtable.h | 7 +++++-- arch/x86/mm/dump_pagetables.c | 3 +-- arch/x86/mm/pti.c | 2 ++ 3 files changed, 8 insertions(+), 4 deletions(-) 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 /* diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c index ccd92c4da57c..b8ab9012ffd6 100644 --- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -569,7 +569,7 @@ void ptdump_walk_pgd_level_debugfs(struct seq_file *m, pgd_t *pgd, bool user) } EXPORT_SYMBOL_GPL(ptdump_walk_pgd_level_debugfs); -static void ptdump_walk_user_pgd_level_checkwx(void) +void ptdump_walk_user_pgd_level_checkwx(void) { #ifdef CONFIG_PAGE_TABLE_ISOLATION pgd_t *pgd = INIT_PGD; @@ -586,7 +586,6 @@ static void ptdump_walk_user_pgd_level_checkwx(void) void ptdump_walk_pgd_level_checkwx(void) { ptdump_walk_pgd_level_core(NULL, NULL, true, false); - ptdump_walk_user_pgd_level_checkwx(); } static int __init pt_dump_init(void) diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c index 1dc5c683e7a5..d58b4aba9510 100644 --- a/arch/x86/mm/pti.c +++ b/arch/x86/mm/pti.c @@ -646,4 +646,6 @@ void pti_finalize(void) */ pti_clone_entry_text(); pti_clone_kernel_text(); + + debug_checkwx_user(); }
