[PATCH v18 09/12] mm: Provide address parameter to p{te,md,ud}_user_accessible_page()

Andrew Donnellan
2025-12-18T17:11:29Z

From: Rohan McLure <rmclure@linux.ibm.com>

On several powerpc platforms, a page table entry may not imply whether
the relevant mapping is for userspace or kernelspace. Instead, such
platforms infer this by the address which is being accessed.

Add an additional address argument to each of these routines in order to
provide support for page table check on powerpc.

[ajd@linux.ibm.com: rebase on arm64 changes]
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Ingo Molnar <mingo@kernel.org> # x86
Acked-by: Alexandre Ghiti <alexghiti@rivosinc.com> # riscv
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
---
v15: rebase
---
arch/arm64/include/asm/pgtable.h | 6 +++---
arch/riscv/include/asm/pgtable.h | 6 +++---
arch/x86/include/asm/pgtable.h | 6 +++---
mm/page_table_check.c | 12 ++++++------
4 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index ce64c560e284e1c2ff9d698cf868070ed58ba045..d94445b4f3dfafcda88c7953a84228d39f788f3a 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1265,17 +1265,17 @@ static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
#endif

#ifdef CONFIG_PAGE_TABLE_CHECK
-static inline bool pte_user_accessible_page(pte_t pte)
+static inline bool pte_user_accessible_page(pte_t pte, unsigned long addr)
{
return pte_valid(pte) && (pte_user(pte) || pte_user_exec(pte));
}

-static inline bool pmd_user_accessible_page(pmd_t pmd)
+static inline bool pmd_user_accessible_page(pmd_t pmd, unsigned long addr)
{
return pmd_valid(pmd) && !pmd_table(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd));
}

-static inline bool pud_user_accessible_page(pud_t pud)
+static inline bool pud_user_accessible_page(pud_t pud, unsigned long addr)
{
return pud_valid(pud) && !pud_table(pud) && (pud_user(pud) || pud_user_exec(pud));
}
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 9af5bfc780800fe2f974daa5329277c46877f848..e38da3f9908fbd32ccb27a4f95c049dc2ae705dc 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -956,17 +956,17 @@ static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
}

#ifdef CONFIG_PAGE_TABLE_CHECK
-static inline bool pte_user_accessible_page(pte_t pte)
+static inline bool pte_user_accessible_page(pte_t pte, unsigned long addr)
{
return pte_present(pte) && pte_user(pte);
}

-static inline bool pmd_user_accessible_page(pmd_t pmd)
+static inline bool pmd_user_accessible_page(pmd_t pmd, unsigned long addr)
{
return pmd_leaf(pmd) && pmd_user(pmd);
}

-static inline bool pud_user_accessible_page(pud_t pud)
+static inline bool pud_user_accessible_page(pud_t pud, unsigned long addr)
{
return pud_leaf(pud) && pud_user(pud);
}
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 6ec6cf7ad2d4d92da7d3396bc96a5b5902e81576..1662c5a8f445f58c62e7364040d13b5958347818 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1680,17 +1680,17 @@ static inline bool arch_has_hw_nonleaf_pmd_young(void)
#endif

#ifdef CONFIG_PAGE_TABLE_CHECK
-static inline bool pte_user_accessible_page(pte_t pte)
+static inline bool pte_user_accessible_page(pte_t pte, unsigned long addr)
{
return (pte_val(pte) & _PAGE_PRESENT) && (pte_val(pte) & _PAGE_USER);
}

-static inline bool pmd_user_accessible_page(pmd_t pmd)
+static inline bool pmd_user_accessible_page(pmd_t pmd, unsigned long addr)
{
return pmd_leaf(pmd) && (pmd_val(pmd) & _PAGE_PRESENT) && (pmd_val(pmd) & _PAGE_USER);
}

-static inline bool pud_user_accessible_page(pud_t pud)
+static inline bool pud_user_accessible_page(pud_t pud, unsigned long addr)
{
return pud_leaf(pud) && (pud_val(pud) & _PAGE_PRESENT) && (pud_val(pud) & _PAGE_USER);
}
diff --git a/mm/page_table_check.c b/mm/page_table_check.c
index de9e54bd27e6f2bce68304a0b3e99b139f33c313..2708c2b3ac1fbd19a0a4528f5a2b27ddbef03adf 100644
--- a/mm/page_table_check.c
+++ b/mm/page_table_check.c
@@ -151,7 +151,7 @@ void __page_table_check_pte_clear(struct mm_struct *mm, unsigned long addr,
if (&init_mm == mm)
return;

- if (pte_user_accessible_page(pte)) {
+ if (pte_user_accessible_page(pte, addr)) {
page_table_check_clear(pte_pfn(pte), PAGE_SIZE >> PAGE_SHIFT);
}
}
@@ -163,7 +163,7 @@ void __page_table_check_pmd_clear(struct mm_struct *mm, unsigned long addr,
if (&init_mm == mm)
return;

- if (pmd_user_accessible_page(pmd)) {
+ if (pmd_user_accessible_page(pmd, addr)) {
page_table_check_clear(pmd_pfn(pmd), PMD_SIZE >> PAGE_SHIFT);
}
}
@@ -175,7 +175,7 @@ void __page_table_check_pud_clear(struct mm_struct *mm, unsigned long addr,
if (&init_mm == mm)
return;

- if (pud_user_accessible_page(pud)) {
+ if (pud_user_accessible_page(pud, addr)) {
page_table_check_clear(pud_pfn(pud), PUD_SIZE >> PAGE_SHIFT);
}
}
@@ -211,7 +211,7 @@ void __page_table_check_ptes_set(struct mm_struct *mm, unsigned long addr,

for (i = 0; i < nr; i++)
__page_table_check_pte_clear(mm, addr + PAGE_SIZE * i, ptep_get(ptep + i));
- if (pte_user_accessible_page(pte))
+ if (pte_user_accessible_page(pte, addr))
page_table_check_set(pte_pfn(pte), nr, pte_write(pte));
}
EXPORT_SYMBOL(__page_table_check_ptes_set);
@@ -241,7 +241,7 @@ void __page_table_check_pmds_set(struct mm_struct *mm, unsigned long addr,

for (i = 0; i < nr; i++)
__page_table_check_pmd_clear(mm, addr + PMD_SIZE * i, *(pmdp + i));
- if (pmd_user_accessible_page(pmd))
+ if (pmd_user_accessible_page(pmd, addr))
page_table_check_set(pmd_pfn(pmd), stride * nr, pmd_write(pmd));
}
EXPORT_SYMBOL(__page_table_check_pmds_set);
@@ -257,7 +257,7 @@ void __page_table_check_puds_set(struct mm_struct *mm, unsigned long addr,

for (i = 0; i < nr; i++)
__page_table_check_pud_clear(mm, addr + PUD_SIZE * i, *(pudp + i));
- if (pud_user_accessible_page(pud))
+ if (pud_user_accessible_page(pud, addr))
page_table_check_set(pud_pfn(pud), stride * nr, pud_write(pud));
}
EXPORT_SYMBOL(__page_table_check_puds_set);

--
2.52.0