[PATCH] m68k stack bounds checking

From: William Lee Irwin III <wli@holomorphy.com>

The stack is now shared with struct thread_info on most arches, not task_t.
This mostly affects get_wchan() and stack usage debug.

arch/m68k/kernel/process.c

@@ -399,7 +399,7 @@ unsigned long get_wchan(struct task_struct *p)
 	stack_page = (unsigned long)(p->thread_info);
 	fp = ((struct switch_stack *)p->thread.ksp)->a6;
 	do {
-		if (fp < stack_page+sizeof(struct task_struct) ||
+		if (fp < stack_page+sizeof(struct thread_info) ||
 		    fp >= 8184+stack_page)
 			return 0;
 		pc = ((unsigned long *)fp)[1];