x86/vm86: Move vm86 fields out of 'thread_struct'

Allocate a separate structure for the vm86 fields.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1438148483-11932-2-git-send-email-brgerst@gmail.com
[ Build fixes. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 9dc9098..34a368d 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -301,14 +301,16 @@
 check_v8086_mode(struct pt_regs *regs, unsigned long address,
 		 struct task_struct *tsk)
 {
+#ifdef CONFIG_VM86
 	unsigned long bit;
 
-	if (!v8086_mode(regs))
+	if (!v8086_mode(regs) || !tsk->thread.vm86)
 		return;
 
 	bit = (address - 0xA0000) >> PAGE_SHIFT;
 	if (bit < 32)
-		tsk->thread.screen_bitmap |= 1 << bit;
+		tsk->thread.vm86->screen_bitmap |= 1 << bit;
+#endif
 }
 
 static bool low_pfn(unsigned long pfn)