| Message ID | 20220923060802.1187520-2-rmclure@linux.ibm.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | [v2,1/3] powerpc: Add common pud_pfn stub for all platforms | expand |
Le 23/09/2022 à 08:08, 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/E 64-bit > systems. > > Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> > --- > V2: Provide missing pud_user implementations, use p{u,m}d_is_leaf. > --- > diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h > index 36956fb440e1..69eed4e03da0 100644 > --- a/arch/powerpc/include/asm/pgtable.h > +++ b/arch/powerpc/include/asm/pgtable.h > @@ -172,6 +172,39 @@ 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); > +} > + > +#ifdef CONFIG_PPC64 > + > +static inline bool pmd_user_accessible_page(pmd_t pmd) > +{ > + return pmd_is_leaf(pmd) && pmd_present(pmd) && pmd_user(pmd); > +} > + > +static inline bool pud_user_accessible_page(pud_t pud) > +{ > + return pud_is_leaf(pud) && pud_present(pud) && pud_user(pud); > +} > + > +#else > + > +static inline bool pmd_user_accessible_page(pmd_t pmd) > +{ > + WARN(1, "pmd: multi-level paging unsupported on ppc32"); > + return false; > +} > + > +static inline bool pud_user_accessible_page(pud_t pud) > +{ > + WARN(1, "pud: multi-level paging unsupported on ppc32"); > + return false; > +} > + > +#endif /* CONFIG_PPC64 */ > + I can't see the point in this splitted implementation PPC64/PPC32. The warning has no added value from my point of view. And multi-level paging IS supported on PPC32, that's 2 level paging, the PMD is folder into the PGD. pmd_is_leaf() and pud_is_leaf() are PPC64 specific. The following could be common to PPC32 and PPC64: +static inline bool pmd_user_accessible_page(pmd_t pmd) +{ + return pmd_leaf(pmd) && pmd_present(pmd) && pmd_user(pmd); +} + +static inline bool pud_user_accessible_page(pud_t pud) +{ + return pud_leaf(pud) && pud_present(pud) && pud_user(pud); +} + pud_user() is defined in include/asm-generic/pgtable-nopmd.h for PPC32. All you have to do is to define a stub pmd_user() for book3s/32 and nohash/32. > #endif /* __ASSEMBLY__ */ > > #endif /* _ASM_POWERPC_PGTABLE_H */
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/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..69eed4e03da0 100644 --- a/arch/powerpc/include/asm/pgtable.h +++ b/arch/powerpc/include/asm/pgtable.h @@ -172,6 +172,39 @@ 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); +} + +#ifdef CONFIG_PPC64 + +static inline bool pmd_user_accessible_page(pmd_t pmd) +{ + return pmd_is_leaf(pmd) && pmd_present(pmd) && pmd_user(pmd); +} + +static inline bool pud_user_accessible_page(pud_t pud) +{ + return pud_is_leaf(pud) && pud_present(pud) && pud_user(pud); +} + +#else + +static inline bool pmd_user_accessible_page(pmd_t pmd) +{ + WARN(1, "pmd: multi-level paging unsupported on ppc32"); + return false; +} + +static inline bool pud_user_accessible_page(pud_t pud) +{ + WARN(1, "pud: multi-level paging unsupported on ppc32"); + return false; +} + +#endif /* CONFIG_PPC64 */ + #endif /* __ASSEMBLY__ */ #endif /* _ASM_POWERPC_PGTABLE_H */
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/E 64-bit systems. Signed-off-by: Rohan McLure <rmclure@linux.ibm.com> --- V2: Provide missing pud_user implementations, use p{u,m}d_is_leaf. --- arch/powerpc/include/asm/book3s/64/pgtable.h | 10 ++++++ arch/powerpc/include/asm/nohash/64/pgtable.h | 10 ++++++ arch/powerpc/include/asm/pgtable.h | 33 ++++++++++++++++++ 3 files changed, 53 insertions(+)