lkml.org 
[lkml]   [2018]   [Mar]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:x86/pti] x86/vsyscall/64: Use proper accessor to update p4d entry
Commit-ID:  f9ee6990bd505ecefa014f5e699b3c4d25860d80
Gitweb: https://git.kernel.org/tip/f9ee6990bd505ecefa014f5e699b3c4d25860d80
Author: Boris Ostrovsky <boris.ostrovsky@oracle.com>
AuthorDate: Mon, 19 Mar 2018 10:31:54 -0400
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Tue, 20 Mar 2018 09:04:51 +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.ostrovsky@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180319143154.3742-1-boris.ostrovsky@oracle.com

---
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));
\
 
 \ /
  Last update: 2018-03-20 09:10    [W:0.066 / U:1.368 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site