Commit-ID: 31ad7f8e7dc94d3b85ccf9b6141ce6dfd35a1781
Gitweb: https://git.kernel.org/tip/31ad7f8e7dc94d3b85ccf9b6141ce6dfd35a1781
Author: Boris Ostrovsky <boris.ostrov...@oracle.com>
AuthorDate: Mon, 19 Mar 2018 10:31:54 -0400
Committer: Ingo Molnar <mi...@kernel.org>
CommitDate: Tue, 20 Mar 2018 12:00:53 +0100
x86/vsyscall/64: Use proper accessor to update P4D entry
Writing to it directly does not work for Xen PV guests.
Fixes: 49275fef986a ("x86/vsyscall/64: Explicitly set _PAGE_USER in the
pagetable hierarchy")
Signed-off-by: Boris Ostrovsky <boris.ostrov...@oracle.com>
Signed-off-by: Thomas Gleixner <t...@linutronix.de>
Reviewed-by: Juergen Gross <jgr...@suse.com>
Acked-by: Andy Lutomirski <l...@kernel.org>
Cc: sta...@vger.kernel.org
Link: https://lkml.kernel.org/r/20180319143154.3742-1-boris.ostrov...@oracle.com
Signed-off-by: Ingo Molnar <mi...@kernel.org>
---
arch/x86/entry/vsyscall/vsyscall_64.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c
b/arch/x86/entry/vsyscall/vsyscall_64.c
index 8560ef68a9d6..317be365bce3 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -347,7 +347,7 @@ void __init set_vsyscall_pgtable_user_bits(pgd_t *root)
set_pgd(pgd, __pgd(pgd_val(*pgd) | _PAGE_USER));
p4d = p4d_offset(pgd, VSYSCALL_ADDR);
#if CONFIG_PGTABLE_LEVELS >= 5
- p4d->p4d |= _PAGE_USER;
+ set_p4d(p4d, __p4d(p4d_val(*p4d) | _PAGE_USER));
#endif
pud = pud_offset(p4d, VSYSCALL_ADDR);
set_pud(pud, __pud(pud_val(*pud) | _PAGE_USER));
