ftrace: sysprof fix

static int copy_stack_frame(const void __user *fp, struct stack_frame *frame)

{

	int ret;

	if (!access_ok(VERIFY_READ, fp, sizeof(*frame)))

		return 0;

	if (__copy_from_user_inatomic(frame, frame_pointer, sizeof(*frame)))

		return 0;

	ret = 1;

	pagefault_disable();

	if (__copy_from_user_inatomic(frame, fp, sizeof(*frame)))

		ret = 0;

	pagefault_enable();

	return 1;

	return ret;

}

static void timer_notify(struct pt_regs *regs, int cpu)

{

	const void __user *frame_pointer;

	struct trace_array_cpu *data;

	struct stack_frame frame;

	struct trace_array *tr;

	const void __user *fp;

	int is_user;

	int i;

	trace_special(tr, data, 0, current->pid, regs->ip);

	frame_pointer = (void __user *)regs->bp;

	fp = (void __user *)regs->bp;

	for (i = 0; i < sample_max_depth; i++) {

		if (!copy_stack_frame(frame_pointer, &frame))

		frame.next_fp = 0;

		frame.return_address = 0;

		if (!copy_stack_frame(fp, &frame))

			break;

		if ((unsigned long)frame_pointer < regs->sp)

		if ((unsigned long)fp < regs->sp)

			break;

		trace_special(tr, data, 1, frame.return_address,

			      (unsigned long)frame_pointer);

		frame_pointer = frame.next_fp;

			      (unsigned long)fp);

		fp = frame.next_fp;

	}

	trace_special(tr, data, 2, current->pid, i);

	/*

	 * Special trace entry if we overflow the max depth:

	 */

	if (i == sample_max_depth)

		trace_special(tr, data, -1, -1, -1);

}