[PATCH 04/24] 32-bit userspace ABI: introduce ARCH_32BIT_OFF_T config option

Yury Norov
2018-06-09T07:42:27Z

On Fri, Jun 08, 2018 at 06:32:07PM +0100, Catalin Marinas wrote:
> On Wed, May 16, 2018 at 11:18:49AM +0300, Yury Norov wrote:
> > diff --git a/arch/Kconfig b/arch/Kconfig
> > index 76c0b54443b1..ee079244dc3c 100644
> > --- a/arch/Kconfig
> > +++ b/arch/Kconfig
> > @@ -264,6 +264,21 @@ config ARCH_THREAD_STACK_ALLOCATOR
> > config ARCH_WANTS_DYNAMIC_TASK_STRUCT
> > bool
> >
> > +config ARCH_32BIT_OFF_T
> > + bool
> > + depends on !64BIT
> > + help
> > + All new 32-bit architectures should have 64-bit off_t type on
> > + userspace side which corresponds to the loff_t kernel type. This
> > + is the requirement for modern ABIs. Some existing architectures
> > + already have 32-bit off_t. This option is enabled for all such
> > + architectures explicitly. Namely: arc, arm, blackfin, cris, frv,
> > + h8300, hexagon, m32r, m68k, metag, microblaze, mips32, mn10300,
> > + nios2, openrisc, parisc32, powerpc32, score, sh, sparc, tile32,
> > + unicore32, x86_32 and xtensa. This is the complete list. Any
> > + new 32-bit architecture should declare 64-bit off_t type on user
> > + side and so should not enable this option.
>
> Do you know if this is the case for riscv and nds32, merged in the
> meantime? If not, I suggest you drop this patch altogether and just
> define force_o_largefile() for arm64/ilp32 as we don't seem to stick to
> "all new 32-bit architectures should have 64-bit off_t".

I wrote this patch at request of Arnd Bergmann. This is actually his
words that all new 32-bit architectures should have 64-bit off_t. So
I was surprized when riscv was merged with 32-bit off_t (and I didn't
follow nds32).

If this rule is still in force, we'd better add new exceptions to this
patch. Otherwise, we can drop it.

Arnd, could you please comment it?

Yury