Re: [PATCH v15 01/26] Documentation/x86: Add CET description

Fāng-ruì Sòng
2020-11-30T19:40:24Z

On Mon, Nov 30, 2020 at 10:34 AM Yu, Yu-cheng <yu-cheng.yu@intel.com> wrote:
>
> On 11/30/2020 10:26 AM, Nick Desaulniers wrote:
> > (In response to https://lore.kernel.org/lkml/20201110162211.9207-2-yu-cheng.yu@intel.com/)
> >
> >> These need to be enabled to build a CET-enabled kernel, and Binutils v2.31
> >> and GCC v8.1 or later are required to build a CET kernel.
> >
> > What about LLVM? Surely CrOS might be of interest to ship this on (we ship the
> > equivalent for aarch64 on Android).
> >
>
> I have not built with LLVM, but think it probably will work as well. I
> will test it.
>
> >> An application's CET capability is marked in its ELF header and can be
> >> verified from the following command output, in the NT_GNU_PROPERTY_TYPE_0
> >> field:
> >>
> >> readelf -n <application> | grep SHSTK
> >> properties: x86 feature: IBT, SHSTK
> >
> > Same for llvm-readelf.
> >
>
> I will add that to the document.
>
> Thanks,
> Yu-cheng

The baseline LLVM version is 10.0.1, which is good enough for clang
-fcf-protection=full, llvm-readelf -n, LLD's .note.gnu.property
handling (the LLD option is `-z force-ibt`, though)

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