Re: [PATCH] coroutine-sigaltstack: Keep SIGUSR2 handler up

[Max Reitz]

On 23.01.21 01:41, Laszlo Ersek wrote:
> On 01/22/21 22:26, Laszlo Ersek wrote:
>
> > I'm drifting towards an overhaul of coroutine-sigaltstack, based on my
> > personal understanding of POSIX, but given that I can absolutely not
> > *test* coroutine-sigaltstack on the platforms where it actually matters,
> > an "overhaul" by me would be reckless.
> >
> > I didn't expect these skeletons when I first read Max's "Thread safety
> > of coroutine-sigaltstack" email :/
> >
> > Max, after having worked on top of your patch for a few hours, I
> > officially endorse your mutex approach. I can't encourage you or myself
> > to touch this code, in good conscience. It's not that it's "bad"; it's
> > inexplicable and (to me) untestable.

On one hand, that’s too bad; on the other perhaps it’s just for the 
better to get all of this out of our minds again (for now)... O:)

> I'm attaching a patch (based on 0e3246263068). I'm not convinced that I
> should take responsibility for this, given the lack of testability on my
> end. So I'm not posting it stand-alone even as an RFC. I've built it and
> have booted one of my existent domains with it, but that's all.

FWIW, it looks good to me.  We should keep it in mind if in the future 
for some reason sigaltstack becomes more important, but for now I’m not 
too sad to abort any improvement efforts.

Max