Re: [PATCH v2] livepatch: x86: bugfix about kASLR

From: Minfei Huang
Date: Wed Nov 11 2015 - 03:46:57 EST


On 11/10/15 at 08:07am, Josh Poimboeuf wrote:
> On Fri, Nov 06, 2015 at 02:25:00PM +0800, Zhou Chengming wrote:
> > When enable KASLR, livepatch will adjust old_addr of changed
> > function accordingly. So do the same thing for reloc.
> >
> > +
> > +#if defined(CONFIG_RANDOMIZE_BASE)
> > + /* If KASLR has been enabled, adjust old value accordingly */
> > + if (kaslr_enabled())
> > + reloc->val += kaslr_offset();
> > +#endif
> > ret = klp_verify_vmlinux_symbol(reloc->name,
> > reloc->val);
> > if (ret)
>
> Zhou, thanks a lot for this fix.
>
> Generally I think this patch is fine. However, Chris J Arges is working
> on another patch[*] which may get rid of reloc->val as an input and make
> this patch obsolete.
>
> So, assuming Chris's patch eventually gets accepted, I don't see a need
> for this one unless anybody wants it as a bug fix for 4.4.
>
> [*] https://lkml.kernel.org/r/1447085770-11729-1-git-send-email-chris.j.arges@xxxxxxxxxxxxx
>

Hi, Josh.

I think Jessica Yu is working on the relative patchset which will
offload relocation logical to the module loader.

Thanks
Minfei
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