xen: set up mmu_ops before trying to set any ptes

xen_setup_stackprotector() ends up trying to set page protections,
so we need to have vm_mmu_ops set up before trying to do so.
Failing to do so causes an early boot crash.

[ Impact: Fix early crash under Xen. ]

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 3439616..23a4d80 100644 (file)
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1075,6 +1075,8 @@ asmlinkage void __init xen_start_kernel(void)
         * Set up some pagetable state before starting to set any ptes.
         */
 
+       xen_init_mmu_ops();
+
        /* Prevent unwanted bits from being set in PTEs. */
        __supported_pte_mask &= ~_PAGE_GLOBAL;
        if (!xen_initial_domain())
@@ -1099,7 +1101,6 @@ asmlinkage void __init xen_start_kernel(void)
         */
        xen_setup_stackprotector();
 
-       xen_init_mmu_ops();
        xen_init_irq_ops();
        xen_init_cpuid_mask();