Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
 {
        struct pt_regs * childregs;
        struct switch_stack * childstack, *stack;
-       unsigned long stack_offset, *retp;
+       unsigned long *retp;
 
-       stack_offset = THREAD_SIZE - sizeof(struct pt_regs);
-       childregs = (struct pt_regs *) ((unsigned long) p->thread_info + stack_offset);
+       childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
 
        *childregs = *regs;
        childregs->d0 = 0;