Re: [PATCH] x86: work around clang IAS bug referencing __force_order

From: Nick Desaulniers
Date: Fri Aug 14 2020 - 20:27:11 EST


On Fri, Aug 14, 2020 at 3:57 PM Nick Desaulniers
<ndesaulniers@xxxxxxxxxx> wrote:
>
> On Fri, Aug 14, 2020 at 2:19 PM Sedat Dilek <sedat.dilek@xxxxxxxxx> wrote:
> >
> > On Fri, Aug 14, 2020 at 7:29 PM Sedat Dilek <sedat.dilek@xxxxxxxxx> wrote:
> > >
> > > Thanks for the proposal.
> > >
> > > I have adapted it to fit my patchset against Linux v5.8.
> > >
> > > Both Debian's GCC-10 and a snapshot version of LLVM toolchain
> > > v11.0.0-rc1+ seems to be OK.
> > >
> >
> > Yupp, OK.
> >
> > I was able to boot FreeDOS 1.2 VM in VirtualBox GUI.
>
> Hi Sedat,
> Apologies, but it's not clear to me precisely which patch you tested.
> Can you please confirm whether you tested:
> 1. Arnd's patch that started this thread.
> 2. My proposed diff adding -fno-addrsig to CFLAGS_powernow-k6.o.
> 3. My proposed diff removing __force_order from the kernel.
>
> I'm hoping you were referring to testing 3., but it's not clear to me.

Ah, sorry, I missed your comment on github:
https://github.com/ClangBuiltLinux/linux/issues/1120#issuecomment-674282107

Ok, I will look at more disassembly next week and hopefully have a
patch ready, with your tested by tag.

--
Thanks,
~Nick Desaulniers