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

[Deepa Dinamani <deepa.kernel@gmail.com>]

On Thu, Jul 5, 2018 at 3:21 PM, Christoph Hellwig <hch@infradead.org> 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.

> 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.

-Deepa