[PATCH 10/26] x86/kasan: prepare clear_pgds() to switch to

[Kirill A. Shutemov]

With folded p4d, pgd_clear() is nop. Change clear_pgds() to use
p4d_clear() instead.

Signed-off-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com>
Cc: Dmitry Vyukov <dvyu...@google.com>
---
 arch/x86/mm/kasan_init_64.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c
index 8d63d7a104c3..733f8ba6a01f 100644
--- a/arch/x86/mm/kasan_init_64.c
+++ b/arch/x86/mm/kasan_init_64.c
@@ -32,8 +32,15 @@ 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);
+               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)
-- 
2.11.0