Re: [RFC PATCH v3 00/20] KCFI support

Peter Zijlstra
2022-07-18T21:47:29Z

On Mon, Jun 13, 2022 at 10:04:12AM -0700, Kees Cook wrote:
> On Fri, Jun 10, 2022 at 04:34:53PM -0700, Sami Tolvanen wrote:
> > KCFI is a proposed forward-edge control-flow integrity scheme for
> > Clang, which is more suitable for kernel use than the existing CFI
> > scheme used by CONFIG_CFI_CLANG. KCFI doesn't require LTO, doesn't
> > alter function references to point to a jump table, and won't break
> > function address equality. The latest LLVM patch is here:
> >
> > https://reviews.llvm.org/D119296
> >
> > This RFC series replaces the current arm64 CFI implementation with
> > KCFI and adds support for x86_64.
>
> I think the "RFC" prefix for this series can be dropped. :)
>
> It looks to me like all of Peter's concerns have been addressed. I'd say
> let's get the Clang side landed, and once that's done, land this via x86
> -tip?
>
> Peter and Will does this sound right to you? It touches arm64, so if
> -tip isn't okay, I could take it in one of my trees?

Sorry, I was a bit pre-occupied with this retbleed crud, I'll try and
have a look at things shortly.