Re: [PATCH v7 15/27] mm: Handle shadow stack page fault

[Peter Zijlstra]

On Thu, Jun 06, 2019 at 01:06:34PM -0700, Yu-cheng Yu wrote:

> diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
> index 75d9d68a6de7..ffcc0be7cadc 100644
> --- a/include/asm-generic/pgtable.h
> +++ b/include/asm-generic/pgtable.h
> @@ -1188,4 +1188,12 @@ static inline bool arch_has_pfn_modify_check(void)
>  #define mm_pmd_folded(mm)	__is_defined(__PAGETABLE_PMD_FOLDED)
>  #endif
>  
> +#ifndef CONFIG_ARCH_HAS_SHSTK
> +#define pte_set_vma_features(pte, vma) pte
> +#define arch_copy_pte_mapping(vma_flags) false

static inline pte_t pte_set_vma_features(pte_t pte, struct vm_area_struct *vma)
{
	return pte;
}

static inline bool arch_copy_pte_mapping(unsigned long vm_flags)
{
	return false;
}

Please, this way we retain function prototype checking.

> +#else
> +pte_t pte_set_vma_features(pte_t pte, struct vm_area_struct *vma);
> +bool arch_copy_pte_mapping(vm_flags_t vm_flags);
> +#endif