Re: [PATCH v6 00/29] Warn on orphan section placement

From: Ingo Molnar
Date: Tue Sep 01 2020 - 04:16:55 EST



* Ingo Molnar <mingo@xxxxxxxxxx> wrote:

>
> * Ingo Molnar <mingo@xxxxxxxxxx> wrote:
>
> >
> > * Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> >
> > > On Fri, Aug 21, 2020 at 12:42:41PM -0700, Kees Cook wrote:
> > > > Hi Ingo,
> > > >
> > > > Based on my testing, this is ready to go. I've reviewed the feedback on
> > > > v5 and made a few small changes, noted below.
> > >
> > > If no one objects, I'll pop this into my tree for -next. I'd prefer it
> > > go via -tip though! :)
> > >
> > > Thanks!
> >
> > I'll pick it up today, it all looks very good now!
>
> One thing I found in testing is that it doesn't handler older LD
> versions well enough:
>
> ld: unrecognized option '--orphan-handling=warn'
>
> Could we just detect the availability of this flag, and emit a warning
> if it doesn't exist but otherwise not abort the build?
>
> This is with:
>
> GNU ld version 2.25-17.fc23

I've resolved this for now by not applying the 5 patches that add the
actual orphan section warnings:

arm64/build: Warn on orphan section placement
arm/build: Warn on orphan section placement
arm/boot: Warn on orphan section placement
x86/build: Warn on orphan section placement
x86/boot/compressed: Warn on orphan section placement

The new asserts plus the actual fixes/enhancements are enough changes
to test for now in any case. :-)

Thanks,

Ingo