[PATCH] xen: x86_64: use more usermode macro

Make use of the user_mode macro where it's possible.  This is useful for Xen
because it will need only to redefine only the macro to a hypervisor call.

Signed-off-by: Vincent Hanquez <vincent.hanquez@cl.cam.ac.uk>
Cc: Ian Pratt <m+Ian.Pratt@cl.cam.ac.uk>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/x86_64/kernel/signal.c

@@ -422,7 +422,7 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset)
 	 * kernel mode. Just return without doing anything
 	 * if so.
 	 */
-	if ((regs->cs & 3) != 3)
+	if (!user_mode(regs))
 		return 1;
 
 	if (try_to_freeze(0))

arch/x86_64/kernel/traps.c

@@ -274,7 +274,7 @@ EXPORT_SYMBOL(dump_stack);
 void show_registers(struct pt_regs *regs)
 {
 	int i;
-	int in_kernel = (regs->cs & 3) == 0;
+	int in_kernel = !user_mode(regs);
 	unsigned long rsp;
 	const int cpu = safe_smp_processor_id(); 
 	struct task_struct *cur = cpu_pda[cpu].pcurrent; 
@@ -318,7 +318,7 @@ void handle_BUG(struct pt_regs *regs)
 	struct bug_frame f;
 	char tmp;
 
-	if (regs->cs & 3)
+	if (user_mode(regs))
 		return; 
 	if (__copy_from_user(&f, (struct bug_frame *) regs->rip, 
 			     sizeof(struct bug_frame)))
@@ -437,7 +437,7 @@ static void do_trap(int trapnr, int signr, char *str,
        }
 #endif
 
-	if ((regs->cs & 3)  != 0) { 
+	if (user_mode(regs)) {
 		struct task_struct *tsk = current;
 
 		if (exception_trace && unhandled_signal(tsk, signr))
@@ -522,7 +522,7 @@ asmlinkage void do_general_protection(struct pt_regs * regs, long error_code)
        }
 #endif
 
-	if ((regs->cs & 3)!=0) { 
+	if (user_mode(regs)) {
 		struct task_struct *tsk = current;
 
 		if (exception_trace && unhandled_signal(tsk, SIGSEGV))
@@ -638,7 +638,7 @@ asmlinkage struct pt_regs *sync_regs(struct pt_regs *eregs)
 	if (eregs == (struct pt_regs *)eregs->rsp)
 		;
 	/* Exception from user space */
-	else if (eregs->cs & 3)
+	else if (user_mode(eregs))
 		regs = ((struct pt_regs *)current->thread.rsp0) - 1;
 	/* Exception from kernel and interrupts are enabled. Move to
  	   kernel process stack. */
@@ -697,7 +697,7 @@ asmlinkage void do_debug(struct pt_regs * regs, unsigned long error_code)
 		 * allowing programs to debug themselves without the ptrace()
 		 * interface.
 		 */
-                if ((regs->cs & 3) == 0)
+                if (!user_mode(regs))
                        goto clear_TF_reenable;
 		/*
 		 * Was the TF flag set by a debugger? If so, clear it now,
@@ -715,7 +715,7 @@ asmlinkage void do_debug(struct pt_regs * regs, unsigned long error_code)
 	info.si_signo = SIGTRAP;
 	info.si_errno = 0;
 	info.si_code = TRAP_BRKPT;
-	if ((regs->cs & 3) == 0) 
+	if (!user_mode(regs))
 		goto clear_dr7; 
 
 	info.si_addr = (void __user *)regs->rip;
@@ -756,7 +756,7 @@ asmlinkage void do_coprocessor_error(struct pt_regs *regs)
 	unsigned short cwd, swd;
 
 	conditional_sti(regs);
-	if ((regs->cs & 3) == 0 &&
+	if (!user_mode(regs) &&
 	    kernel_math_error(regs, "kernel x87 math error"))
 		return;
 
@@ -822,7 +822,7 @@ asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
 	unsigned short mxcsr;
 
 	conditional_sti(regs);
-	if ((regs->cs & 3) == 0 &&
+	if (!user_mode(regs) &&
         	kernel_math_error(regs, "kernel simd math error"))
 		return;
 

arch/x86_64/mm/fault.c

@@ -74,7 +74,7 @@ static noinline int is_prefetch(struct pt_regs *regs, unsigned long addr,
 	instr = (unsigned char *)convert_rip_to_linear(current, regs);
 	max_instr = instr + 15;
 
-	if ((regs->cs & 3) != 0 && instr >= (unsigned char *)TASK_SIZE)
+	if (user_mode(regs) && instr >= (unsigned char *)TASK_SIZE)
 		return 0;
 
 	while (scan_more && instr < max_instr) { 
@@ -106,7 +106,7 @@ static noinline int is_prefetch(struct pt_regs *regs, unsigned long addr,
 			/* Could check the LDT for lm, but for now it's good
 			   enough to assume that long mode only uses well known
 			   segments or kernel. */
-			scan_more = ((regs->cs & 3) == 0) || (regs->cs == __USER_CS);
+			scan_more = (!user_mode(regs)) || (regs->cs == __USER_CS);
 			break;
 
 		case 0x60: