Re: [RFC PATCH 10/21] treewide: Drop function_nocfi

Sami Tolvanen
2022-05-05T16:52:16Z

On Thu, May 5, 2022 at 9:30 AM Mark Rutland <mark.rutland@arm.com> wrote:
> I also believe that in most cases we can drop the __nocfi annotation on callers
> now that we can mark the called assembly function with SYM_TYPED_FUNC_START().

Good point, thanks for pointing that out. I'll add these to the next
version of the series.

> There' a latent bug here with the existing CFI scheme, since
> `kpti_install_ng_mappings` isn't marked with __nocfi, and should explode when
> calling `idmap_kpti_install_ng_mappings` via the idmap.

The CONFIG_UNMAP_KERNEL_AT_EL0 version of kpti_install_ng_mappings is
marked __nocfi

> There' a latent bug here with the existing CFI scheme, since
> `machine_kexec` isn't marked with __nocfi, and should explode when calling
> `cpu_soft_restart` via the idmap.

But it's indeed missing from this one.

Sami