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

Arnd Bergmann
2018-06-11T07:48:02Z

On Sat, Jun 9, 2018 at 9:42 AM, Yury Norov <ynorov@caviumnetworks.com> wrote:
> 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?

I completely forgot about it and had assumed that it was merged long
ago, sorry about that.

Arnd