Re: [PATCH v2 1/2] x86/asm: Pin sensitive CR4 bits

From: Kees Cook
Date: Wed Jun 05 2019 - 10:32:56 EST


On Tue, Jun 04, 2019 at 04:44:21PM -0700, Kees Cook wrote:
> diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
> index 2c57fffebf9b..6b210be12734 100644
> --- a/arch/x86/kernel/cpu/common.c
> +++ b/arch/x86/kernel/cpu/common.c
> @@ -366,6 +366,23 @@ static __always_inline void setup_umip(struct cpuinfo_x86 *c)
> cr4_clear_bits(X86_CR4_UMIP);
> }
>
> +DEFINE_STATIC_KEY_FALSE_RO(cr_pinning);
> +unsigned long cr4_pinned_bits __ro_after_init;

I missed EXPORT_SYMBOL()s for these -- I will fix in v3.

--
Kees Cook