Re: [PATCH] lkdtm: don't move ctors to .rodata

From: Stephen Boyd
Date: Thu Feb 11 2021 - 13:55:10 EST


Quoting Greg Kroah-Hartman (2021-02-11 06:23:10)
> On Wed, Feb 10, 2021 at 04:36:08PM -0800, Stephen Boyd wrote:
> > Quoting Greg Kroah-Hartman (2020-12-09 06:51:33)
> > > On Tue, Dec 08, 2020 at 01:20:56PM -0800, Kees Cook wrote:
> > > > On Mon, Dec 07, 2020 at 05:05:33PM +0000, Mark Rutland wrote:
> > > > > [ 0.969110] Code: 00000003 00000000 00000000 00000000 (00000000)
> > > > > [ 0.970815] ---[ end trace b5339784e20d015c ]---
> > > > >
> > > > > Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
> > > >
> > > > Oh, eek. Why was a ctor generated at all? But yes, this looks good.
> > > > Greg, can you pick this up please?
> > > >
> > > > Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
> > >
> > > Now picked up, thanks.
> > >
> >
> > Can this be backported to 5.4 and 5.10 stable trees? I just ran across
> > this trying to use kasan on 5.4 with lkdtm and it blows up early. This
> > patch applies on 5.4 cleanly but doesn't compile because it's missing
> > noinstr. Here's a version of the patch that introduces noinstr on 5.4.97
> > so this patch can be picked to 5.4 stable trees.
>
> Why 5.10? This showed up in 5.8, so how would it be needed there?
>

Sorry for the confusion. Can commit 655389666643 ("vmlinux.lds.h: Create
section for protection against instrumentation") and commit 3f618ab33234
("lkdtm: don't move ctors to .rodata") be backported to 5.4.y and only
commit 3f618ab3323407ee4c6a6734a37eb6e9663ebfb9 be backported to 5.10.y?