math_state_restore() question

[Hiro Yoshioka <lkml.hyoshiok@gmail.com>]

Hi,

I have a quick question.

The math_state_restore() restores the FPU/MMX/XMM states.
However where do we save the previous task's states if it is necessary?

asmlinkage void math_state_restore(struct pt_regs regs)
{
        struct thread_info *thread = current_thread_info();
        struct task_struct *tsk = thread->task;

        clts();         /* Allow maths ops (or we recurse) */
        if (!tsk_used_math(tsk))
                init_fpu(tsk);
        restore_fpu(tsk);
        thread->status |= TS_USEDFPU;   /* So we fnsave on switch_to() */
}

Thanks in advance,
  Hiro
-- 
Hiro Yoshioka
mailto:hyoshiok at miraclelinux.com