[PATCH] uml: remove jail mode + other leftovers

This var is currently useless, as it's apparent from reading the code. Until
2.6.11 it was used in some code related to jail mode, in the same proc.:

        if(jail){
		while(!reading) sched_yield();
	}

jail mode has been dropped, together with that use, so let's finish dropping
this.

Also, remove some other useless definitions I met.
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/um/kernel/tt/process_kern.c

@@ -32,10 +32,6 @@ void *switch_to_tt(void *prev, void *next, void *last)
 	unsigned long flags;
 	int err, vtalrm, alrm, prof, cpu;
 	char c;
-	/* jailing and SMP are incompatible, so this doesn't need to be 
-	 * made per-cpu 
-	 */
-	static int reading;
 
 	from = prev;
 	to = next;
@@ -59,13 +55,11 @@ void *switch_to_tt(void *prev, void *next, void *last)
 	c = 0;
 	set_current(to);
 
-	reading = 0;
 	err = os_write_file(to->thread.mode.tt.switch_pipe[1], &c, sizeof(c));
 	if(err != sizeof(c))
 		panic("write of switch_pipe failed, err = %d", -err);
 
-	reading = 1;
-        if(from->thread.mode.tt.switch_pipe[0] == -1)
+	if(from->thread.mode.tt.switch_pipe[0] == -1)
 		os_kill_process(os_getpid(), 0);
 
 	err = os_read_file(from->thread.mode.tt.switch_pipe[0], &c, sizeof(c));

arch/um/kernel/um_arch.c

@@ -111,12 +111,6 @@ struct seq_operations cpuinfo_op = {
 	.show	= show_cpuinfo,
 };
 
-pte_t * __bad_pagetable(void)
-{
-	panic("Someone should implement __bad_pagetable");
-	return(NULL);
-}
-
 /* Set in linux_main */
 unsigned long host_task_size;
 unsigned long task_size;

include/asm-um/pgtable.h

@@ -114,17 +114,9 @@ extern unsigned long end_iomem;
 extern unsigned long pg0[1024];
 
 /*
- * BAD_PAGETABLE is used when we need a bogus page-table, while
- * BAD_PAGE is used for a bogus page.
- *
  * ZERO_PAGE is a global shared page that is always zero: used
  * for zero-mapped memory areas etc..
  */
-extern pte_t __bad_page(void);
-extern pte_t * __bad_pagetable(void);
-
-#define BAD_PAGETABLE __bad_pagetable()
-#define BAD_PAGE __bad_page()
 
 #define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)