Re: RFD: x32 ABI system call numbers

["H. Peter Anvin" <hpa@zytor.com>]

> 
>> #define __NR_x32_ioctl
> 
> What do you plan to do for ioctl? Does this mean you want to
> have a third file_operations pointer besides ioctl and compat_ioctl?
> I would hope that you manage this by using different ioctl command
> numbers in the few cases where the x32 version has to differ from
> the x86-32 data structure.
> 

This *should* just be an entry for compat_ioctl in the x86-64 system
call table (as opposed to the i386 system call table.)

>> #define __NR_x32_readv
>> #define __NR_x32_writev
>> #define __NR_x32_preadv
>> #define __NR_x32_pwritev
>> #define __NR_x32_vmsplice
>> #define __NR_x32_move_pages
>> #define __NR_x32_execve
>> #define __NR_x32_set_robust_list
>> #define __NR_x32_get_robust_list
>> #define __NR_x32__sysctl
>> #define __NR_x32_kexec_load
>> #define __NR_x32_times
> 
> I guess you could define the x32 iovec etc. to be compatible with the
> 64 bit one, but that's not a major thing. Why can't you use the
> regular x86_32 calls here?

They still need to be bound to x86-64 system call entry points.  (Well,
in theory they could be invoked via int $0x80, but that is ugly in a
whole lot of ways.)

>> #define __NR_x32_recvfrom
>> #define __NR_x32_sendmsg
>> #define __NR_x32_recvmsg
>> #define __NR_x32_recvmmsg
>> #define __NR_x32_sendmmsg
> 
> These today use the MSG_CMSG_COMPAT flag to distinguish native and compat
> calls. Do you plan to have another flag here to handle cmsg time values?
> 
> What about things like mq_{get,set}attr, quotactl and semtimedop?

	-hpa