[PATCH -next v4 3/4] arm64: mm: add support for page table check

[Anshuman Khandual]

On 4/18/22 09:14, Tong Tiangen wrote:
> +#ifdef CONFIG_PAGE_TABLE_CHECK
> +static inline bool pte_user_accessible_page(pte_t pte)
> +{
> +	return pte_present(pte) && (pte_user(pte) || pte_user_exec(pte));
> +}
> +
> +static inline bool pmd_user_accessible_page(pmd_t pmd)
> +{
> +	return pmd_present(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd));
> +}
> +
> +static inline bool pud_user_accessible_page(pud_t pud)
> +{
> +	return pud_present(pud) && pud_user(pud);
> +}
> +#endif
Wondering why check for these page table entry states when init_mm
has already being excluded ? Should not user page tables be checked
for in entirety for all updates ? what is the rationale for filtering
out only pxx_user_access_page entries ?