Re: [PATCH v4] livepatch: Cleanup module page permission changes

From: Josh Poimboeuf
Date: Fri Dec 04 2015 - 17:07:38 EST


On Fri, Dec 04, 2015 at 10:57:45PM +0100, Jiri Kosina wrote:
> On Fri, 4 Dec 2015, Josh Poimboeuf wrote:
>
> > > (1) I pull your 'modules-next' branch, apply this patch on top, and wait
> > > for your merge with Linus and send merge request afterwards
> > > (2) If you are okay with rebasing your tree (seems like this is
> > > ocassionally happening), how about you prepare a branch that'd have
> > > just b3212ec77 ("module: keep percpu symbols in module's symtab") on
> > > top of some common base, I merge it, and the cross-dependency is gone
> > > (3) I cherry-pick b3212ec77 ("module: keep percpu symbols in
> > > module's symtab") from your tree, and apply this on top. git will
> > > handle duplicate commits when Linus merges both just fine
> > > (4) I sign this patch off and you merge it
> > >
> > > (4) seems really outside the regular process. (1) is really tricky wrt.
> > > coordination of timing during the merge window. I'd prefer (2) (more
> > > git-ish way of doing things, but would require you rebasing your tree) or
> > > eventually (3) (git will handle this with grace).
> >
> > [ off-list ]
>
> :-)
>
> > Quick question. Just curious, because I'm new at this...
> >
> > My impression was that #1 was standard operating procedure. Merge a
> > (non-rebasable) modules branch into livepatch, and then make sure to
> > submit the livepatch pull request after Rusty sends his, with a note in
> > the mail to Linus stating the dependency. That seems pretty
> > straightforward to me. Or am I missing something?
>
> It's one of the options, yes. The only drawback is that it introduces, in
> addition to the actual code cross-dependency, also maintainer timing
> cross-dependency, and it might easily go wrong during merge window. But
> I've done this quite a few times already, and it was rather smooth.
>
> What I actually prefer doing in this case is have a common merge base as a
> separate branch that gets merged to both trees, and then it's not really
> important who merges first. But that'd require in-advance planning and
> structuring Rusty's tree for that, and that's probably not worth the
> hassle for these few patches.

Ah, got it. That does sound better, assuming there's some advance
planning. Thanks for educating me :-)

--
Josh
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/