Re: [patch] Rename CAP_EPOLLWAKEUP to CAL_BLOCK_SUSPEND

From: Rafael J. Wysocki
Date: Tue Jul 17 2012 - 14:59:38 EST


On Tuesday, July 17, 2012, Serge E. Hallyn wrote:
> Quoting Michael Kerrisk (man-pages) (mtk.manpages@xxxxxxxxx):
> > On Tue, Jul 17, 2012 at 3:46 PM, Serge E. Hallyn <serge@xxxxxxxxxx> wrote:
> > > Quoting Michael Kerrisk (mtk.manpages@xxxxxxxxx):
> > >> Rafael,
> > >>
> > >> As discussed in
> > >> http://thread.gmane.org/gmane.linux.kernel/1249726/focus=1288990,
> > >> the capability introduced in 4d7e30d98939a0340022ccd49325a3d70f7e0238
> > >> to govern EPOLLWAKEUP seems misnamed: this capability is about governing
> > >> the ability to suspend the system, not using a particular API flag
> > >> (EPOLLWAKEUP). We should make the name of the capability more general
> > >> to encourage reuse in related cases. (Whether or not this capability
> > >> should also be used to govern the use of /sys/power/wake_lock is a
> > >> question that needs to be separately resolved.)
> > >>
> > >> This patch renames the capability to CAP_BLOCK_SUSPEND. In order to ensure
> > >> that the old capability name doesn't make it out into the wild, could you
> > >> please apply and push up the tree to ensure that it is incorporated
> > >> for the 3.5 release.
> > >>
> > >> Thanks,
> > >>
> > >> Michael
> > >>
> > >> Signed-off-by: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
> > >
> > > I definately like that name better, thanks. Don't know if renaming it
> > > without an alias could cause trouble for some bleeding edge userspaces?
> > > Would it be worth keeping the
> > >
> > > #define CAP_EPOLLWAKEUP 36
> > >
> > > line? If this is deemed early enough I do prefer not to complicate with
> > > a duplicate name.
> >
> > Maybe I'm too ignorant. Are there userspaces that bleed with the -rc
> > series? I'd have thought this renaming would be a fairly safe change
> > at this point.

I'm not so sure of that, but then I think it will be less painful
to do it now rather than later.

> I'm sure there are, but I'm not sure what we've promised them.

I can't recall making any promises to anyone in that respect, but then
people have had quite enough time to get used to the existing name already.

> Like I say if at all possible I do prefer not to keep CAP_EPOLLWAKEUP.

I will push the Michael's patch to Linus for v3.5, if it's not too late,
but I'm not pleased by the timing of this, to put it lightly.

Thanks,
Rafael
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