Re: [PATCH v6 13/17] arm64:ilp32: add sys_ilp32.c and a separate table (in entry.S) to use it

From: Arnd Bergmann
Date: Fri Nov 13 2015 - 10:35:31 EST


On Thursday 12 November 2015 14:47:18 Andreas Schwab wrote:
> Arnd Bergmann <arnd@xxxxxxxx> writes:
>
> > On Thursday 12 November 2015 10:44:55 Andreas Schwab wrote:
> >> Arnd Bergmann <arnd@xxxxxxxx> writes:
> >>
> >> > What do you mean with 32-bit off_t?
> >>
> >> An ABI with 32-bit off_t, ie. all currently implemented 32-bit ABIs.
> >>
> >> > Do you mean that glibc emulates a 32-bit off_t on top of the 64-bit
> >> > __kernel_loff_t?
> >>
> >> Glibc is bridging the user-space ABI to the kernel ABI.
> >
> > Ok, but why?
>
> That's how the ABI is defined right now. I didn't make that up.

Ok, I guess it will remain a mystery then.

Should we perhaps define __ARCH_WANT_SYSCALL_OFF_T for the unistd.h
file then, so we provide both the off_t and the loff_t based syscalls?

That would avoid the extra wrapper in glibc when using a 32-bit
off_t if that is the preferred mode for user space.

Arnd
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