Re: [PATCH 2/6] kernel: add task_sigpending() helper

[Oleg Nesterov]

On 10/05, Jens Axboe wrote:
>
> @@ -4447,7 +4447,7 @@ SYSCALL_DEFINE0(pause)
>  		__set_current_state(TASK_INTERRUPTIBLE);
>  		schedule();
>  	}
> -	return -ERESTARTNOHAND;
> +	return task_sigpending(current) ? -ERESTARTNOHAND : -ERESTARTSYS;
>  }
>
>  #endif
> @@ -4462,7 +4462,7 @@ static int sigsuspend(sigset_t *set)
>  		schedule();
>  	}
>  	set_restore_sigmask();
> -	return -ERESTARTNOHAND;
> +	return task_sigpending(current) ? -ERESTARTNOHAND : -ERESTARTSYS;
>  }

Both changes are equally wrong. Why do you think sigsuspend() should ever
return -ERESTARTSYS ?

If get_signal() deques a signal, handle_signal() will restart this syscall
if ERESTARTSYS, this is wrong.

Oleg.