Re: [PATCH] riscv: add asm/unistd.h UAPI header

[Arnd Bergmann]

On Wed, Nov 7, 2018 at 7:30 PM David Abdurachmanov
<david.abdurachmanov@xxxxxxxxx> wrote:
> On Wed, Nov 7, 2018 at 1:08 AM Palmer Dabbelt <palmer@xxxxxxxxxx> wrote:
> > On Mon, 05 Nov 2018 12:56:15 PST (-0800), Arnd Bergmann wrote:

> > The target is still the next glibc release (Feb 1st) for a stable RV32I ABI.
> > That's progressing well, with one last blocking issue related to some of our
> > floating-point emulation routines before we can submit the port.  This should
> > give us ample time to line up the ABIs correctly so everything works.
> >
> > So I think the correct answer here is to drop __ARCH_WANT_STAT64 from RISC-V.
> >
>
> Then if you agree I could do and send v2:
>
> +#ifdef __LP64__
> +#define __ARCH_WANT_NEW_STAT
> +#endif /* __LP64__ */

Looks good to me.

> Cannot use CONFIG_64BIT as in user space nothing defines it.
> Alternatively I could
> check for __riscv_xlen == 64.
>
> I found _LP64 and __LP64__ being used in kernel, incl. include/uapi/linux/rseq.h

I think older gcc versions were less consistent about those macros, which
is why I introduced __BITS_PER_LONG a long time ago. We now support
gcc-4.6 as the minimum, so using __LP64__ is reliable, and on RISC-V
we obviously have a much newer compiler anyway.

        Arnd