Re: [RFC PATCH v9 04/27] x86/cet: Add control-protection fault handler

[Yu-cheng Yu]

On Wed, 2020-02-26 at 09:10 -0800, Dave Hansen wrote:
> On 2/5/20 10:19 AM, Yu-cheng Yu wrote:
> > diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
> > index 87ef69a72c52..8ed406f469e7 100644
> > --- a/arch/x86/kernel/idt.c
> > +++ b/arch/x86/kernel/idt.c
> > @@ -102,6 +102,10 @@ static const __initconst struct idt_data def_idts[] = {
> >  #elif defined(CONFIG_X86_32)
> >  	SYSG(IA32_SYSCALL_VECTOR,	entry_INT80_32),
> >  #endif
> > +
> > +#ifdef CONFIG_X86_64
> > +	INTG(X86_TRAP_CP,		control_protection),
> > +#endif
> >  };
> 
> This patch in particular appears to have all of its code unconditionally
> compiled in.  That's in contrast to things that have Kconfig options, like:
> 
> #ifdef CONFIG_X86_MCE
>         INTG(X86_TRAP_MC,               &machine_check),
> #endif
> 
> or:
> 
> #ifdef CONFIG_X86_THERMAL_VECTOR
>         INTG(THERMAL_APIC_VECTOR,       thermal_interrupt),
> #endif
> 
> Is there a reason this code is always compiled in on 64-bit even when
> the config option is off?

I will change it to CONFIG_X86_INTEL_CET.

Yu-cheng