[PATCH v8 6/7] powerpc: mm: Add p{te,md,ud}_user_accessible_page helpers
From: Rohan McLure <hidden>
Date: 2023-02-15 23:18:56
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
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.
Reviewed-by: Christophe Leroy <redacted>
Signed-off-by: Rohan McLure <redacted>
---
V2: Provide missing pud_user implementations, use p{u,m}d_is_leaf.
V3: Provide missing pmd_user implementations as stubs in 32-bit.
V4: Use pmd_leaf, pud_leaf, and define pmd_user for 32 Book3E with
static inline method rather than macro.
---
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 | 5 +++++
arch/powerpc/include/asm/nohash/64/pgtable.h | 10 ++++++++++
arch/powerpc/include/asm/pgtable.h | 15 +++++++++++++++
5 files changed, 44 insertions(+)
diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h
index a090cb13a4a0..afd672e84791 100644
--- a/arch/powerpc/include/asm/book3s/32/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/32/pgtable.h@@ -516,6 +516,10 @@ 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 df5ee856444d..a6ed93d01da1 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h@@ -538,6 +538,16 @@ 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 70edad44dff6..d953533c56ff 100644
--- a/arch/powerpc/include/asm/nohash/32/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/32/pgtable.h@@ -209,6 +209,11 @@ static inline void pmd_clear(pmd_t *pmdp) *pmdp = __pmd(0); } +static inline bool pmd_user(pmd_t pmd) +{ + return false; +} + /* * PTE updates. This function is called whenever an existing * valid PTE is updated. This does -not- include set_pte_at()
diff --git a/arch/powerpc/include/asm/nohash/64/pgtable.h b/arch/powerpc/include/asm/nohash/64/pgtable.h
index d391a45e0f11..14e69ebad31f 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))
@@ -164,6 +169,11 @@ 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 ad0829f816e9..b76fdb80b6c9 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h@@ -167,6 +167,21 @@ 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_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); +} + #endif /* __ASSEMBLY__ */ #endif /* _ASM_POWERPC_PGTABLE_H */
--
2.37.2