x86/asm/entry: Replace some open-coded VM86 checks with v8086_mode() checks

This allows us to remove some unnecessary ifdefs.  There should
be no change to the generated code.

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/f7e00f0d668e253abf0bd8bf36491ac47bd761ff.1426728647.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index d4e265952102923ad2aa3dc305831c2d4b6039ee..c8eb469a94a46e803ee04c2ea2699859403facff 100644 (file)
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -194,8 +194,7 @@ static nokprobe_inline int
 do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str,
                  struct pt_regs *regs, long error_code)
 {
-#ifdef CONFIG_X86_32
-       if (regs->flags & X86_VM_MASK) {
+       if (v8086_mode(regs)) {
                /*
                 * Traps 0, 1, 3, 4, and 5 should be forwarded to vm86.
                 * On nmi (interrupt 2), do_trap should not be called.
@@ -207,7 +206,7 @@ do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str,
                }
                return -1;
        }
-#endif
+
        if (!user_mode_ignore_vm86(regs)) {
                if (!fixup_exception(regs)) {
                        tsk->thread.error_code = error_code;
@@ -462,13 +461,11 @@ do_general_protection(struct pt_regs *regs, long error_code)
        prev_state = exception_enter();
        conditional_sti(regs);
 
-#ifdef CONFIG_X86_32
-       if (regs->flags & X86_VM_MASK) {
+       if (v8086_mode(regs)) {
                local_irq_enable();
                handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
                goto exit;
        }
-#endif
 
        tsk = current;
        if (!user_mode_ignore_vm86(regs)) {
@@ -673,7 +670,7 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code)
        /* It's safe to allow irq's after DR6 has been saved */
        preempt_conditional_sti(regs);
 
-       if (regs->flags & X86_VM_MASK) {
+       if (v8086_mode(regs)) {
                handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code,
                                        X86_TRAP_DB);
                preempt_conditional_cli(regs);