Re: [PATCH 0/3] clone64() and unshare64() system calls

["H. Peter Anvin" <hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>]

sukadev-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org wrote:
>>
>> If you're going to make it a 64-bit pass it in as a 64-bit number, instead 
>> of breaking it into two numbers.
> 
> Maybe I am missing your point. The glibc interface could take a 64bit
> parameter, but don't we need to pass 32-bit values into the system call 
> on 32 bit systems ?

Not as such, no.  The ABI handles that.  To make the ABI clean on some 
architectures, it's good to consider a 64-bit value only in positions 
where they map to an even:odd register pair once slotted in.

> Yes, this was discussed before in the context of Pavel Emelyanov's patch
> 
> 	http://lkml.org/lkml/2008/1/16/109
> 
> along with sys_indirect().  While there was no consensus, it looked like
> adding a new system call was better than open ended interfaces.

That's not really an open-ended interface, it's just an expandable bitmap.

	-hpa