Re: [PATCH v2 3/7] riscv: Include asm-generic/compat.h

[Geert Uytterhoeven]

Hi Arnd,

On Fri, Jul 6, 2018 at 1:43 PM Arnd Bergmann <arnd@xxxxxxxx> wrote:
> On Fri, Jul 6, 2018 at 1:56 AM, Deepa Dinamani <deepa.kernel@xxxxxxxxx> wrote:
> > On Thu, Jul 5, 2018 at 3:21 PM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
> >> On Thu, Jul 05, 2018 at 02:36:00PM -0700, Deepa Dinamani wrote:
> >>> defconfig, allmodconfig and nomodconfig.
> >>> And hence does not inlude definitions for compat data types.
> >>>
> >>> Now that time syscalls are being reused in non CONFIG_COMPAT
> >>> modes, include asm-generic definitions for riscv.
> >>>
> >>> Alternative would be to make compat_time.h to be conditional on
> >>> CONFIG_COMPAT_32BIT_TIME. But, since riscv is already has an
> >>> asm/compat.h include the generic version instead.
> >>
> >> Two comments here:
> >>
> >> First I think the current riscv compat.h is completely bogus.
> >> As you mentioned riscv does not actually have a compat mode, so
> >> having a compat.h makes no sensse at all, and the COMPAT_UTS_MACHINE
> >> override which is the only thing implemented is included in that
> >> statement.
> >
> > I was leaving the decision on how to clean up compat mode to the
> > architecture maintainers.
> > I wasn't sure if they were still in the middle of implementing it.
>
> If we only need it for 32 bit time_t, we can probably just use the
> asm-generic/compat.h for now.
>
> >> Second I think abusing compat.h for old syscall compatibility of any
> >> form is a really bad idea.  I think you need to split that part out,
> >> and preferably not using compat in the name, but something like
> >> old-time.h or time32.h for the name.
> >
> > Are you talking about just the header file or the way we are reusing
> > compat syscalls?
> > Either way, we have merged quite a few patches this way already.
> > I agree that having something like time32.h might be less confusing.
> > But, if you are worried about the former, then maybe we should propose
> > a cleanup after we finish what we are doing or back out the merged
> > patches.
> > For instance, posix_clock apis have already been changed this way.
>
> It would be easy to rename compat_time_t, compat_timespec and
> compat_timeval to something else if we could come up with a good
> name for them (we already have too many variants of each of
> them though, otherwise we end up being more confusing rather
> than less).

legacy_time_t etc.?

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds