Re: [PATCHv2 2/3] kernel: add support for live patching

From: Miroslav Benes
Date: Fri Nov 21 2014 - 09:41:10 EST


On Thu, 20 Nov 2014, Seth Jennings wrote:

> On Thu, Nov 20, 2014 at 11:35:52AM -0600, Josh Poimboeuf wrote:
> > On Thu, Nov 20, 2014 at 02:10:33PM +0100, Miroslav Benes wrote:
> > >
> > > On Sun, 16 Nov 2014, Seth Jennings wrote:
> > >
> > > > This commit introduces code for the live patching core. It implements
> > > > an ftrace-based mechanism and kernel interface for doing live patching
> > > > of kernel and kernel module functions.
> > > >
> > > > It represents the greatest common functionality set between kpatch and
> > > > kgraft and can accept patches built using either method.
> > > >
> > > > This first version does not implement any consistency mechanism that
> > > > ensures that old and new code do not run together. In practice, ~90% of
> > > > CVEs are safe to apply in this way, since they simply add a conditional
> > > > check. However, any function change that can not execute safely with
> > > > the old version of the function can _not_ be safely applied in this
> > > > version.
> > > >
> > > > Signed-off-by: Seth Jennings <sjenning@xxxxxxxxxx>
> > >
> > > Hi,
> > >
> > > below is the patch which merges the internal and external data structures
> > > (so it is only one part of our original patch for version 1). Apart from
> > > that I tried to make minimal changes to the code. Only unnecessary
> > > kobjects were removed and I renamed lpc_create_* functions to lpc_init_*
> > > as it made more sense in this approach, I think.
> > >
> > > I hope this clearly shows our point of view stated previously. What do
> > > you say?
> >
> > Thanks for rebasing to v2 and splitting up the patches! Personally I'm
> > ok with this patch (though I do have a few comments below).
>
> Thanks Josh :)
>
> Miroslav, before you send out a revision on this patch, I'm merging it
> for v3 right now. I'll fixup any trivial fixes from this email.
>
> I'm putting the finishing touches on v3 now. Hopefully it will make
> everyone happy, or happier, with your changes merged. Should be getting
> close...
>
> Thanks,
> Seth

Ok, thank you for the fixes and merging. I'll take a closer look at v3 to
be sure that everything is ok.

Mira
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