RE: [PATCH] signal: remove the wrong signal_pending() check in restore_user_sigmask()

[David Laight]

From: Oleg Nesterov [mailto:oleg@xxxxxxxxxx]
> Sent: 05 June 2019 10:25
> On 06/05, David Laight wrote:
> >
> > epoll() would have:
> > 	if (restore_user_sigmask(xxx.sigmask, &sigsaved, !ret || ret == -EINTR))
> > 		ret = -EINTR;
> 
> I don't think so but lets discuss this later.

I certainly think there should be some comments at least
about when/whether signal handlers get called and that
being separate from the return value.

The system call restart stuff does seem strange.
ISTR that was originally added for SIG_SUSPEND (^Z) so that those
signals wouldn't be seen by the appication.
But that makes it a property of the signal, not the system call.

> > I also think it could be simplified if code that loaded the 'user sigmask'
> > saved the old one in 'current->saved_sigmask' (and saved that it had done it).
> > You'd not need 'sigsaved' nor pass the user sigmask address into
> > the restore function.
> 
> Heh. apparently you do not read my emails ;)
> 
> This is what I proposed in my very 1st email, and I even showed the patch
> and the code with the patch applied twice. Let me do this again.

I did read that one, I've even quoted it in the past :-)
It's just not been mentioned recently.

	David

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