Re: [PATCH 1/2] clone3: add CLONE3_CLEAR_SIGHAND

Michael Kerrisk (man-pages)
2019-10-12T06:53:49Z

Hello Aleksa,

On Sat, 12 Oct 2019 at 00:12, Aleksa Sarai <cyphar@cyphar.com> wrote:
>
> On 2019-10-11, Michael Kerrisk <mtk.manpages@gmail.com> wrote:
> > Why CLONE3_CLEAR_SIGHAND rather than just CLONE_CLEAR_SIGHAND?
>
> There are no more flag bits left for the classic clone()/clone2() (the
> last one was used up by CLONE_PIDFD) -- thus this flag is clone3()-only.

Yes, I understand that. But, I'm not sure that the "3" in the prefix
is necessary. "CLONE_" still seems better to me.

Consider this: sometime in the near future we will probably have time
namespaces. The new flag for those namespaces will only be usable with
clone3(). It should NOT be called CLONE3_NEWTIME, but rather
CLONE_NEWTIME (or similar), because that same flag will presumably
also be used in other APIs such as unshare() and setns(). (Hmm -- I
wonder if we are going to need a new unshare2() or some such...)

Thanks,

Michael

--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/