uml: use UM_THREAD_SIZE in userspace code

Now that we have UM_THREAD_SIZE, we can replace the calculations in
user-space code (an earlier patch took care of the kernel side of the
house).
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/um/kernel/init_task.c

@@ -44,8 +44,7 @@ __attribute__((__section__(".data.init_task"))) =
 
 void unprotect_stack(unsigned long stack)
 {
-	os_protect_memory((void *) stack, (1 << CONFIG_KERNEL_STACK_ORDER) * PAGE_SIZE,
-		       1, 1, 0);
+	os_protect_memory((void *) stack, THREAD_SIZE, 1, 1, 0);
 }
 
 /*

arch/um/os-Linux/skas/process.c

@@ -490,8 +490,8 @@ void map_stub_pages(int fd, unsigned long code,
 void new_thread(void *stack, jmp_buf *buf, void (*handler)(void))
 {
 	(*buf)[0].JB_IP = (unsigned long) handler;
-	(*buf)[0].JB_SP = (unsigned long) stack +
-		(PAGE_SIZE << UML_CONFIG_KERNEL_STACK_ORDER) - sizeof(void *);
+	(*buf)[0].JB_SP = (unsigned long) stack + UM_THREAD_SIZE -
+		sizeof(void *);
 }
 
 #define INIT_JMP_NEW_THREAD 0
@@ -533,8 +533,7 @@ int start_idle_thread(void *stack, jmp_buf *switch_buf)
 	case INIT_JMP_NEW_THREAD:
 		(*switch_buf)[0].JB_IP = (unsigned long) new_thread_handler;
 		(*switch_buf)[0].JB_SP = (unsigned long) stack +
-			(PAGE_SIZE << UML_CONFIG_KERNEL_STACK_ORDER) -
-			sizeof(void *);
+			UM_THREAD_SIZE - sizeof(void *);
 		break;
 	case INIT_JMP_CALLBACK:
 		(*cb_proc)(cb_arg);