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

From: Dominik Brodowski
Date: Wed Feb 20 2019 - 03:20:26 EST


On Tue, Feb 19, 2019 at 04:54:49PM -0800, Kees Cook wrote:
> diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
> index cb28e98a0659..7e0ea4470f8e 100644
> --- a/arch/x86/kernel/cpu/common.c
> +++ b/arch/x86/kernel/cpu/common.c
> @@ -312,10 +312,16 @@ static __init int setup_disable_smep(char *arg)
> }
> __setup("nosmep", setup_disable_smep);
>
> +volatile unsigned long cr4_pin __ro_after_init;
> +EXPORT_SYMBOL_GPL(cr4_pin);

Where is this export needed?

Thanks,
Dominik