Commit-ID: d691a3cf8004784303f0a4c1c036edfaa7d64d0b Gitweb: http://git.kernel.org/tip/d691a3cf8004784303f0a4c1c036edfaa7d64d0b Author: Kirill A. Shutemov <[email protected]> AuthorDate: Fri, 17 Mar 2017 21:55:13 +0300 Committer: Ingo Molnar <[email protected]> CommitDate: Mon, 27 Mar 2017 08:56:41 +0200
x86/kasan: Prepare clear_pgds() to switch to <asm-generic/pgtable-nop4d.h> With folded p4d, pgd_clear() is a nop. Change clear_pgds() to use p4d_clear() instead. Signed-off-by: Kirill A. Shutemov <[email protected]> Acked-by: Thomas Gleixner <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/mm/kasan_init_64.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c index 8d63d7a..7b81f01 100644 --- a/arch/x86/mm/kasan_init_64.c +++ b/arch/x86/mm/kasan_init_64.c @@ -32,8 +32,19 @@ static int __init map_range(struct range *range) static void __init clear_pgds(unsigned long start, unsigned long end) { - for (; start < end; start += PGDIR_SIZE) - pgd_clear(pgd_offset_k(start)); + pgd_t *pgd; + + for (; start < end; start += PGDIR_SIZE) { + pgd = pgd_offset_k(start); + /* + * With folded p4d, pgd_clear() is nop, use p4d_clear() + * instead. + */ + if (CONFIG_PGTABLE_LEVELS < 5) + p4d_clear(p4d_offset(pgd, start)); + else + pgd_clear(pgd); + } } static void __init kasan_map_early_shadow(pgd_t *pgd)
