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

Joseph Myers joseph at codesourcery.com
Mon Nov 16 04:03:09 PST 2015

On Mon, 16 Nov 2015, Arnd Bergmann wrote:

> There are two separate aspects here:
> a) leave out the support for all __off_t based syscalls (__ftruncate,
>    __lseek, __lxstat, __pread, __preadv, __pwrite, __pwritev, __truncate,
>    __xstat) as they are no longer needed, and change the handling of
>    _FILE_OFFSET_BITS so that we default to 64 and error out for anything
>    else.
>    This needs to be done for all new 32-bit architectures if you think we
>    should use a 64-bit off_t from now on, it's not arm64 specific.

It's not a matter of leaving anything out - these would simply use 64-bit 
off_t (__off_t and __off64_t would be the same type) and the *64 versions 
would be aliases, exactly the same as on 64-bit architectures.  (And 
_FILE_OFFSET_BITS handling would also be exactly the same as on 64-bit 
architectures.)  I see no reason for the set of off_t-related symbols that 
exist, or which symbols are aliases of which others, to vary between pure 
64-bit systems and ILP32 ABIs (for 32-bit or 64-bit architectures) that 
simply happen to have had 64-bit off_t from the start.

Joseph S. Myers
joseph at codesourcery.com

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