x86/mm: Do not use paravirtualized calls in native_set_p4d()

In 4-level paging mode, native_set_p4d() updates the entry in the top-level
page table. With PTI, update to the top-level kernel page table requires
update to the userspace copy of the table as well, using pti_set_user_pgd().

native_set_p4d() uses p4d_val() and pgd_val() to convert types between
p4d_t and pgd_t.

p4d_val() and pgd_val() are paravirtualized and we must not use them in
native helpers, as they crash the boot in paravirtualized environments.

Replace p4d_val() and pgd_val() with native_p4d_val() and
native_pgd_val() in native_set_p4d().

Reported-by: Fengguang Wu <[email protected]>
Signed-off-by: Kirill A. Shutemov <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Fixes: 91f606a8fa68 ("x86/mm: Replace compile-time checks for 5-level paging with runtime-time checks")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
index 81dda8d1d0bd..163e01a0631d 100644
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -224,9 +224,9 @@ static inline void native_set_p4d(p4d_t *p4dp, p4d_t p4d)
 		return;
 	}
 
-	pgd = native_make_pgd(p4d_val(p4d));
+	pgd = native_make_pgd(native_p4d_val(p4d));
 	pgd = pti_set_user_pgd((pgd_t *)p4dp, pgd);
-	*p4dp = native_make_p4d(pgd_val(pgd));
+	*p4dp = native_make_p4d(native_pgd_val(pgd));
 }
 
 static inline void native_p4d_clear(p4d_t *p4d)