[CRIU] [PATCH] compel: Do not loose sign of result in compat syscall

[Cyrill Gorcunov]

On Tue, Oct 31, 2017 at 01:14:21PM +0000, Dmitry Safonov wrote:
> >>
> >> Ok, I see, the sign extension.
> >> It's not a very lovely solution but should work.
> >
> > We didn't merge any into vanilla criu yet, so if you have a better
> > idea -- you are more than welcome!
> 
> I know, I didn't mean to say that your idea is bad,
> that looks like they are all a bit of ugly:
> 
> 1. Check (map & 0xffffffff) - this one
> 2. The way it's done in mmap_bug_test(): (map % PAGE_SIZE)
> 3. Add IS_ERR_VALUE(x, compat) (the ugliest, IMHO)

Sure thing. And that's why I pointed that better ideas are
more than welcome :)