Re: [RFC PATCH] x86/split_lock: Disable SLD if an unaware (out-of-tree) module enables VMX

[Peter Zijlstra <peterz@infradead.org>]

On Mon, Apr 06, 2020 at 04:04:04PM +0200, Peter Zijlstra wrote:
> diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
> index 65c2ecd730c5..0bd5ea46f1d2 100644
> --- a/arch/x86/include/asm/pgtable_types.h
> +++ b/arch/x86/include/asm/pgtable_types.h
> @@ -274,6 +274,11 @@ typedef struct pgprot { pgprotval_t pgprot; } pgprot_t;
>  
>  typedef struct { pgdval_t pgd; } pgd_t;
>  

This lost:

#define pgprot_nx pgprot_nx

> +static inline pgprot_t pgprot_nx(pgprot_t prot)
> +{
> +	return __pgprot(pgprot_val(prot) | _PAGE_NX);
> +}
> +
>  #ifdef CONFIG_X86_PAE
>  
>  /*

> diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
> index e2e2bef07dd2..ee66c1f8b141 100644
> --- a/include/asm-generic/pgtable.h
> +++ b/include/asm-generic/pgtable.h
> @@ -490,6 +490,10 @@ static inline int arch_unmap_one(struct mm_struct *mm,
>  #define flush_tlb_fix_spurious_fault(vma, address) flush_tlb_page(vma, address)
>  #endif
>  
> +#ifndef pgprot_nx
> +#define pgprot_nx(prot)	(prot)
> +#endif
> +
>  #ifndef pgprot_noncached
>  #define pgprot_noncached(prot)	(prot)
>  #endif