Re: [PATCH 3/6] kernel: split syscall restart from signal handling

Oleg Nesterov
2020-10-08T14:45:47Z

On 10/08, Jens Axboe wrote:
>
> On 10/8/20 8:21 AM, Oleg Nesterov wrote:
> >
> > Can't we avoid this patch and the and simplify the change in
> > exit_to_user_mode_loop() from the next patch? Can't the much more simple
> > patch below work?
> >
> > Then later we can even change arch_do_signal() to accept the additional
> > argument, ti_work, so that it can use ti_work & TIF_NOTIFY_SIGNAL/SIGPENDING
> > instead of test_thread_flag/task_sigpending.
>
> Yeah I guess that would be a bit simpler, maybe I'm too focused on
> decoupling the two. But if we go this route, and avoid sighand->lock for
> just having TIF_NOTIFY_SIGNAL set, then that should be functionally
> equivalent as far as I'm concerned.

Not sure I understand... I think that the change I propose is functionally
equivalent or I missed something.

> I'll make the reduction, I'd prefer to keep this as small/simple as
> possible initially.

Great, thanks.

Oleg.