> On 3 Nov 2022, at 7:02 pm, Christophe Leroy <christophe.le...@csgroup.eu> > wrote: > > > > Le 24/10/2022 à 02:35, Rohan McLure a écrit : >> Add the following helpers for detecting whether a page table entry >> is a leaf and is accessible to user space. >> >> * pte_user_accessible_page >> * pmd_user_accessible_page >> * pud_user_accessible_page >> >> Also implement missing pud_user definitions for both Book3S/nohash 64-bit >> systems, and pmd_user for Book3S/nohash 32-bit systems. >> >> Signed-off-by: Rohan McLure <rmcl...@linux.ibm.com> >> --- >> V2: Provide missing pud_user implementations, use p{u,m}d_is_leaf. >> V3: Provide missing pmd_user implementations as stubs in 32-bit. >> --- >> arch/powerpc/include/asm/book3s/32/pgtable.h | 4 ++++ >> arch/powerpc/include/asm/book3s/64/pgtable.h | 10 ++++++++++ >> arch/powerpc/include/asm/nohash/32/pgtable.h | 1 + >> arch/powerpc/include/asm/nohash/64/pgtable.h | 10 ++++++++++ >> arch/powerpc/include/asm/pgtable.h | 15 +++++++++++++++ >> 5 files changed, 40 insertions(+) >> >> diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h >> b/arch/powerpc/include/asm/book3s/32/pgtable.h >> index 40041ac713d9..8bf1c538839a 100644 >> --- a/arch/powerpc/include/asm/book3s/32/pgtable.h >> +++ b/arch/powerpc/include/asm/book3s/32/pgtable.h >> @@ -531,6 +531,10 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t >> newprot) >> return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot)); >> } >> >> +static inline bool pmd_user(pmd_t pmd) >> +{ >> + return 0; >> +} >> >> >> /* This low level function performs the actual PTE insertion >> diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h >> b/arch/powerpc/include/asm/book3s/64/pgtable.h >> index f9aefa492df0..3083111f9d0a 100644 >> --- a/arch/powerpc/include/asm/book3s/64/pgtable.h >> +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h >> @@ -621,6 +621,16 @@ static inline bool pte_user(pte_t pte) >> return !(pte_raw(pte) & cpu_to_be64(_PAGE_PRIVILEGED)); >> } >> >> +static inline bool pmd_user(pmd_t pmd) >> +{ >> + return !(pmd_raw(pmd) & cpu_to_be64(_PAGE_PRIVILEGED)); >> +} >> + >> +static inline bool pud_user(pud_t pud) >> +{ >> + return !(pud_raw(pud) & cpu_to_be64(_PAGE_PRIVILEGED)); >> +} >> + >> #define pte_access_permitted pte_access_permitted >> static inline bool pte_access_permitted(pte_t pte, bool write) >> { >> diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h >> b/arch/powerpc/include/asm/nohash/32/pgtable.h >> index 9091e4904a6b..b92044d9d778 100644 >> --- a/arch/powerpc/include/asm/nohash/32/pgtable.h >> +++ b/arch/powerpc/include/asm/nohash/32/pgtable.h >> @@ -354,6 +354,7 @@ static inline int pte_young(pte_t pte) >> #endif >> >> #define pmd_page(pmd) pfn_to_page(pmd_pfn(pmd)) >> +#define pmd_user(pmd) 0 >> /* >> * Encode and decode a swap entry. >> * Note that the bits we use in a PTE for representing a swap entry >> diff --git a/arch/powerpc/include/asm/nohash/64/pgtable.h >> b/arch/powerpc/include/asm/nohash/64/pgtable.h >> index 599921cc257e..23c5135178d1 100644 >> --- a/arch/powerpc/include/asm/nohash/64/pgtable.h >> +++ b/arch/powerpc/include/asm/nohash/64/pgtable.h >> @@ -123,6 +123,11 @@ static inline pte_t pmd_pte(pmd_t pmd) >> return __pte(pmd_val(pmd)); >> } >> >> +static inline bool pmd_user(pmd_t pmd) >> +{ >> + return (pmd_val(pmd) & _PAGE_USER) == _PAGE_USER; >> +} >> + >> #define pmd_none(pmd) (!pmd_val(pmd)) >> #define pmd_bad(pmd) (!is_kernel_addr(pmd_val(pmd)) \ >> || (pmd_val(pmd) & PMD_BAD_BITS)) >> @@ -158,6 +163,11 @@ static inline pte_t pud_pte(pud_t pud) >> return __pte(pud_val(pud)); >> } >> >> +static inline bool pud_user(pud_t pud) >> +{ >> + return (pud_val(pud) & _PAGE_USER) == _PAGE_USER; >> +} >> + >> static inline pud_t pte_pud(pte_t pte) >> { >> return __pud(pte_val(pte)); >> diff --git a/arch/powerpc/include/asm/pgtable.h >> b/arch/powerpc/include/asm/pgtable.h >> index 36956fb440e1..3cb5de9f1aa4 100644 >> --- a/arch/powerpc/include/asm/pgtable.h >> +++ b/arch/powerpc/include/asm/pgtable.h >> @@ -172,6 +172,21 @@ static inline int pud_pfn(pud_t pud) >> } >> #endif >> >> +static inline bool pte_user_accessible_page(pte_t pte) >> +{ >> + return pte_present(pte) && pte_user(pte); >> +} >> + >> +static inline bool pmd_user_accessible_page(pmd_t pmd) >> +{ >> + return pmd_is_leaf(pmd) && pmd_present(pmd) && pmd_user(pmd); > > pmd_is_leaf() is specific to powerpc and we may want to get rid of it. > > Can you use pmd_leaf() instead ? > >> +} >> + >> +static inline bool pud_user_accessible_page(pud_t pud) >> +{ >> + return pud_is_leaf(pud) && pud_present(pud) && pud_user(pud); > > pud_is_leaf() is specific to powerpc and we may want to get rid of it. > > Can you use pud_leaf() instead ?
Going to resend, replacing all usages/definitions of p{m,u,4}d_is_leaf() with p{m,u,4}_leaf() in arch/powerpc prior to this patch. > >> +} >> + >> #endif /* __ASSEMBLY__ */ >> >> #endif /* _ASM_POWERPC_PGTABLE_H */