Re: [PATCH] unshare: Cleanup up the sys_unshare interface before we are committed.

[Posted March 21, 2006 by corbet]

From:		Andrew Morton <akpm-AT-osdl.org>
To:		ebiederm-AT-xmission.com (Eric W. Biederman)
Subject:		Re: [PATCH] unshare: Cleanup up the sys_unshare interface before we are committed.
Date:		Thu, 16 Mar 2006 14:19:27 -0800
Cc:		torvalds-AT-osdl.org, linux-kernel-AT-vger.kernel.org, janak-AT-us.ibm.com, viro-AT-ftp.linux.org.uk, hch-AT-lst.de, mtk-manpages-AT-gmx.net, ak-AT-muc.de, paulus-AT-samba.org

ebiederm@xmission.com (Eric W. Biederman) wrote:
>
> Linus Torvalds <torvalds@osdl.org> writes:
> 
> > On Thu, 16 Mar 2006, Andrew Morton wrote:
> >> 
> >> iirc there was some discussion about this and it was explicitly decided to
> >> keep the CLONE flags.
> >> 
> >> Maybe Janak or Linus can comment?
> >
> > My personal opinion is that having a different set of flags is more 
> > confusing and likely to result in problems later than having the same 
> > ones. Regardless, I'm not touching this for 2.6.16 any more, 
> 
> I am actually a lot more concerned with the fact that we don't test
> for invalid bits.  So we have an ABI that will change in the future,
> and that doesn't allow us to have a program that runs on old and new
> kernels.

The risk of breaking things is small - it would require someone to write a
sys_unshare-using app which a) they care about and b) has a particular bug
in it.  But yes, we should check.

> I guess I can resend some version of my patch after 2.6.16 is out and
> break the ABI for the undefined bits then.  Correct programs shouldn't
> care.  But it sure would be nice if they could care.
> 

Your single patch did two different things - there's a lesson here ;)