x86/asm/entry: Use user_mode_ignore_vm86() where appropriate

A few of the user_mode() checks in traps.c are immediately after
explicit checks for vm86 mode.  Change them to user_mode_ignore_vm86().

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/0b324d5b75c3402be07f8d3c6245ed7f4995029e.1426728647.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/traps.c

@@ -208,7 +208,7 @@ do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str,
 		return -1;
 	}
 #endif
-	if (!user_mode(regs)) {
+	if (!user_mode_ignore_vm86(regs)) {
 		if (!fixup_exception(regs)) {
 			tsk->thread.error_code = error_code;
 			tsk->thread.trap_nr = trapnr;
@@ -471,7 +471,7 @@ do_general_protection(struct pt_regs *regs, long error_code)
 #endif
 
 	tsk = current;
-	if (!user_mode(regs)) {
+	if (!user_mode_ignore_vm86(regs)) {
 		if (fixup_exception(regs))
 			goto exit;
 
@@ -688,7 +688,7 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code)
 	 * We already checked v86 mode above, so we can check for kernel mode
 	 * by just checking the CPL of CS.
 	 */
-	if ((dr6 & DR_STEP) && !user_mode(regs)) {
+	if ((dr6 & DR_STEP) && !user_mode_ignore_vm86(regs)) {
 		tsk->thread.debugreg6 &= ~DR_STEP;
 		set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
 		regs->flags &= ~X86_EFLAGS_TF;