Re: [RESEND PATCH 2/6] x86/traps: add a system interrupt table for system interrupt dispatch

From: Peter Zijlstra
Date: Fri Nov 11 2022 - 04:02:57 EST


On Thu, Nov 10, 2022 at 08:36:30PM +0000, Li, Xin3 wrote:
> > > > +#pragma GCC diagnostic push
> > > > +#pragma GCC diagnostic ignored "-Wcast-function-type"
> > >
> > > How does this not break CFI ?
> >
> > I wasn't aware of it, will check.
>
> CFI needs $(cc-option,-fsanitize=kcfi), which, reported on LWN on Jun, 2002,
> had not yet landed in the LLVM mainline (I'm using GCC). So looks we are
> replying on people keeping an eye on it to make sure it's not broken?

We're relying on that warning you disabled.

> Even we are unable to test it now, we should find a solution.

You can test this just fine. Build llvm.git and compile a kernel with
CFI_CLANG=y. This is not hard, my ADL runs such a kernel as we speak.