4.14-stable review patch. If anyone has any objections, please let me know.
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From: Boris Ostrovsky boris.ostrovsky@oracle.com
commit 31ad7f8e7dc94d3b85ccf9b6141ce6dfd35a1781 upstream.
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 Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/entry/vsyscall/vsyscall_64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/entry/vsyscall/vsyscall_64.c +++ b/arch/x86/entry/vsyscall/vsyscall_64.c @@ -355,7 +355,7 @@ void __init set_vsyscall_pgtable_user_bi 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));