Re: [RFC v5 13/38] x86: disallow pkey creation with PKEY_DISABLE_EXECUTE

[Dave Hansen]

On 07/05/2017 02:21 PM, Ram Pai wrote:
> x86 does not support disabling execute permissions on a pkey.
> 
> Signed-off-by: Ram Pai <linuxram@xxxxxxxxxx>
> ---
>  arch/x86/kernel/fpu/xstate.c |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
> index c24ac1e..d582631 100644
> --- a/arch/x86/kernel/fpu/xstate.c
> +++ b/arch/x86/kernel/fpu/xstate.c
> @@ -900,6 +900,9 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
>  	if (!boot_cpu_has(X86_FEATURE_OSPKE))
>  		return -EINVAL;
>  
> +	if (init_val & PKEY_DISABLE_EXECUTE)
> +		return -EINVAL;

I'd really rather that we define a supported mask instead of having each
architecture go through and list which ones it supports.