On Thu, Jun 16, 2022 at 04:41:05PM +0000, Sean Christopherson wrote:
> > I worry that another use of cc_platform_has() could creep in at some point
> > and cause the same issue. Not sure how bad it would be, performance-wise, to
> > remove the jump table optimization for arch/x86/coco/core.c.
Is there a gcc switch for that?
> One thought would be to initialize "vendor" to a bogus value, disallow calls to
> cc_set_vendor() until after the kernel as gotten to a safe point, and then WARN
> (or panic?) if cc_platform_has() is called before "vendor" is explicitly set.
> New calls can still get in, but they'll be much easier to detect and less likely
> to escape initial testing.
The invalid vendor thing makes sense but I don't think it'll help in
this case.
We set vendor in sme_enable() which comes before the
__startup_64 -> sme_postprocess_startup
path you're hitting.
We could do only the aspect of checking whether it hasn't been set yet
and warn then, in order to make the usage more robust...
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
