Re: [PATCH v2 1/3] rust: make mutually exclusive with CFI_CLANG

Conor Dooley
2024-02-27T10:54:50Z

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On Fri, Feb 23, 2024 at 03:45:10PM +0100, Miguel Ojeda wrote:
> On Fri, Feb 23, 2024 at 2:38 PM Conor Dooley <conor@kernel.org> wrote:
> >
> > configuring a kernel without symmetrical support for kfi.
>
> Nit: typo.
>
> > This probably needs to go to stable. The correct fixes tag for that I am
> > not sure of however, but since CFI_CLANG predates RUST, I blamed the
> > commit adding rust support.
>
> Cc'ing Matthew et al. in case this is a problem for them, but I guess
> we can relax it later as needed.

I suspect that nobody has actually sat down and tried it.

I did try to test it but I ran into too many toolchain issues - my
older copies of LLVM (pre 17) are not multiarch as I built them by hand
with PGO for x86 and RISC-V. My LLVM 17 is from kernel.org and has no
libclang. And then the copy of LLVM 18 on kernel.org apparently does not
support kcfi at all. I gave up there, but I don't see how this would not
be a problem on other arches, given rustc never gets told to enable
kcfi.

Cheers,
Conor.

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