Re: [PATCH] x86/Kconfig: make CFI_AUTO_DEFAULT depend on !RUST

[Alice Ryhl]

On Thu, Apr 10, 2025 at 4:15 PM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> On Thu, Apr 10, 2025 at 04:05:54PM +0200, Miguel Ojeda wrote:
> > On Thu, Apr 10, 2025 at 3:57 PM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> > If you mean fixing it upstream, definitely, but we should still
> > prevent people from building an invalid kernel, i.e. when Alice's PR
> > or similar lands upstream, then we can relax the `depends on` based on
> > the Rust version (which is something we have done for other bits).
>
> So why wasn't any of this a problem when Rust enabled kCFI? Surely the
> testing back then included FineIBT. That has been in longer than rust's
> kcfi support (integer type confusion etc.).

I assume this has been a problem for a while. The testing we did with
FineIBT must not have triggered this codepath. But Rust drivers have
used the codepath for a long time.

Alice