Re: [PATCH v5 1/3] Provide in-kernel headers to make extending kernel easier

[Karim Yaghmour]

On 4/16/19 9:04 AM, Joel Fernandes wrote:
> On Tue, Apr 16, 2019 at 02:49:39PM +0200, Greg Kroah-Hartman wrote:
> > On Tue, Apr 16, 2019 at 08:33:06AM -0400, Steven Rostedt wrote:
> > > On Mon, 15 Apr 2019 22:50:10 -0500
> > > Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> > >
> > > > On Mon, Apr 15, 2019 at 9:41 AM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> > > > > I agree with this assessment. We shouldn't use config.gz as precedence
> > > > > for this solution. config.gz should have been in debugfs to begin with,
> > > > > but I don't believe debugfs was around when config.gz was introduced.
> > > > > (Don't have time to look into the history of the two).
> > > >
> > > > I don't agree with this: /proc/config.gz is used by a lot of tools
> > > > that do sanity-check of running systems. This isn't _debugging_...
> > > > it's verifying correct kernel builds. It's a fancy version of checking
> > > > /proc/version.
> > >
> > > Then we should perhaps make a new file system call tarballs ;-)
> > >
> > >   /sys/kernel/tarballs/
> > >
> > > and place everything there. That way it removes it from /proc (which is
> > > the worse place for that) and also makes it something other than debug.
> > > That's what I did for tracefs.
> >
> > As horrible as that suggestion is, it does kind of make sense :)
> >
> > We can't put this in debugfs as that's only for debugging and systems
> > should never have that mounted for normal operations (users want to
> > build ebpf programs), and /proc really should be for processes but that
> > horse is long left the barn.
> >
> > But, I'm willing to consider putting this either in a system-fs-like
> > filesystem, or just in sysfs itself, we do have /sys/kernel/ to play
> > around in if the main objection is that we should not be cluttering up
> > /proc with stuff like this.
>
> I am ok with the suggestion of /sys/kernel for the archive. That also seems
> to fit well with the idea that the headers are kernel related and probably
> belong here more strictly speaking, than /proc.

This makes sense. And if it alleviates concerns regarding extending 
/proc ABIs then might as well switch to this.

Olof, what do you think of this?

--
Karim Yaghmour
CEO - Opersys inc. / www.opersys.com
http://twitter.com/karimyaghmour