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

[Joseph Myers]

On Mon, 16 Nov 2015, Arnd Bergmann wrote:

> Let's not get into the tv_nsec discussion today, that is not thankfully
> not relevant for arm64 any more at this point. The system call ABI for
> arm64/ilp32 is now the same as for any other 32-bit architecture using
> the generic ABI, the question we're trying to solve here is only whether it
> is ok for new 32-bit glibc ports to only offer a 64-bit off_t as the kernel
> currently does (using __kernel_loff_t) or if we still need to support the
> _FILE_OFFSET_BITS=32 case.
> 
> If I got you right, we can use 64-bit off_t now, so we just need someone
> to figure out how to make that the default in glibc for new architectures
> while keeping the existing 32-bit architectures unchanged.

It would be an entirely new combination.  Presumably such a port would 
want the "function X is an alias of function Y" aspects of wordsize-64 
directories (where that relates to off_t, struct stat etc. as opposed to 
long and long long), and the "registers are 64-bit so 64-bit operations 
are efficient" aspects, but not all the "64-bit syscall interface" 
aspects, so someone would need to review wordsize-64 sysdeps files and 
figure out what is or is not relevant to this port.

-- 
Joseph S. Myers
joseph at codesourcery.com