[PATCH] powerpc: task_stack_page()

Signed-off-by: Al Viro <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/powerpc/kernel/process.c

···
 {
 	struct pt_regs *childregs, *kregs;
 	extern void ret_from_fork(void);
-	unsigned long sp = (unsigned long)p->thread_info + THREAD_SIZE;
+	unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
 
 	CHECK_FULL_REGS(regs);
 	/* Copy registers */
···
 	 * set.  Do it now.
 	 */
 	if (!current->thread.regs) {
-		unsigned long childregs = (unsigned long)current->thread_info +
-						THREAD_SIZE;
-		childregs -= sizeof(struct pt_regs);
-		current->thread.regs = (struct pt_regs *)childregs;
+		struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
+		current->thread.regs = regs - 1;
 	}
 
 	memset(regs->gpr, 0, sizeof(regs->gpr));
···
 static int validate_sp(unsigned long sp, struct task_struct *p,
 		       unsigned long nbytes)
 {
-	unsigned long stack_page = (unsigned long)p->thread_info;
+	unsigned long stack_page = (unsigned long)task_stack_page(p);
 
 	if (sp >= stack_page + sizeof(struct thread_struct)
 	    && sp <= stack_page + THREAD_SIZE - nbytes)

arch/ppc/kernel/process.c

···
 {
 	struct pt_regs *childregs, *kregs;
 	extern void ret_from_fork(void);
-	unsigned long sp = (unsigned long)p->thread_info + THREAD_SIZE;
+	unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
 	unsigned long childframe;
 
 	CHECK_FULL_REGS(regs);
···
 			sp = tsk->thread.ksp;
 	}
 
-	prev_sp = (unsigned long) (tsk->thread_info + 1);
-	stack_top = (unsigned long) tsk->thread_info + THREAD_SIZE;
+	prev_sp = (unsigned long) end_of_stack(tsk);
+	stack_top = (unsigned long) task_stack_page(tsk) + THREAD_SIZE;
 	while (count < 16 && sp > prev_sp && sp < stack_top && (sp & 3) == 0) {
 		if (count == 0) {
 			printk("Call trace:");
···
 unsigned long get_wchan(struct task_struct *p)
 {
 	unsigned long ip, sp;
-	unsigned long stack_page = (unsigned long) p->thread_info;
+	unsigned long stack_page = (unsigned long) task_stack_page(p);
 	int count = 0;
 	if (!p || p == current || p->state == TASK_RUNNING)
 		return 0;