Re: [PATCH v2 4/5] pselect6: use __kernel_timespec

[Thomas Gleixner]

On Sat, 15 Sep 2018, Deepa Dinamani wrote:

> On Sat, Sep 15, 2018 at 8:28 AM Arnd Bergmann <arnd@xxxxxxxx> wrote:
> >
> > On Sat, Sep 15, 2018 at 7:09 AM Deepa Dinamani <deepa.kernel@xxxxxxxxx> wrote:
> >
> > > +#if defined(CONFIG_64BIT_TIME)
> > > +
> > > +COMPAT_SYSCALL_DEFINE6(pselect6_time64, int, n, compat_ulong_t __user *, inp,
> > > +       compat_ulong_t __user *, outp, compat_ulong_t __user *, exp,
> > > +       struct __kernel_timespec __user *, tsp, void __user *, sig)
> >
> > I got a link error here since compat_sys_pselect6_time64 and
> > compat_sys_ppoll_time64 are only defined when CONFIG_64BIT_TIME
> > is set.
> >
> > I did not think we would select this symbol on arm64, is that a mistake
> > on my side, or should the #ifdef check be removed?
> 
> But, this is a compat syscall.
> When we introduced this CONFIG_64BIT_TIME we planned to use it for
> compat syscalls also is my understanding.
> 
> config 64BIT_TIME
>          def_bool ARCH_HAS_64BIT_TIME
>          help
>           This should be selected by all architectures that need to support
>            new system calls with a 64-bit time_t. This is relevant on all 32-bit
>            architectures, and 64-bit architectures as part of compat syscall
>            handling.
> 
> This means it should be set on 64 bit architechtures also right?

It's only set when 32bit compat mode is enabled on the 64bit kernel.

Thanks,

	tglx