{
        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)
 
 {
        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;