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 ?