[PATCH v6 13/17] arm64:ilp32: add sys_ilp32.c and a separate table (in entry.S) to use it
pinskia at gmail.com
Fri Nov 13 07:38:49 PST 2015
On Fri, Nov 13, 2015 at 7:34 AM, Arnd Bergmann <arnd at arndb.de> wrote:
> On Thursday 12 November 2015 14:47:18 Andreas Schwab wrote:
>> Arnd Bergmann <arnd at arndb.de> writes:
>> > On Thursday 12 November 2015 10:44:55 Andreas Schwab wrote:
>> >> Arnd Bergmann <arnd at arndb.de> 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.
The biggest question is here is how much compatibility do we want with
other 32bit ABIs?
Do we want off_t to be 32bit or 64bit?
> 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?
I think that is backwards ...
> That would avoid the extra wrapper in glibc when using a 32-bit
> off_t if that is the preferred mode for user space.
Other targets like tilegx does not do that and has a pure 32bit mode.
Only score does that.
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