[PATCH v15 07/13] mm/page_table_check: Reinstate address parameter in [__]page_table_check_pmd_clear()

From: Andrew Donnellan
Date: Wed Jun 25 2025 - 03:32:43 EST


From: Rohan McLure <rmclure@xxxxxxxxxxxxx>

This reverts commit 1831414cd729 ("mm/page_table_check: remove unused
parameter in [__]page_table_check_pmd_clear").

Reinstate previously unused parameters for the purpose of supporting
powerpc platforms, as many do not encode user/kernel ownership of the
page in the pte, but instead in the address of the access.

[ajd@xxxxxxxxxxxxx: rebase on arm64 changes]
Signed-off-by: Rohan McLure <rmclure@xxxxxxxxxxxxx>
Reviewed-by: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxxxxx> # x86
Signed-off-by: Andrew Donnellan <ajd@xxxxxxxxxxxxx>
---
v15: rebase
---
arch/arm64/include/asm/pgtable.h | 2 +-
arch/riscv/include/asm/pgtable.h | 2 +-
arch/x86/include/asm/pgtable.h | 2 +-
include/linux/page_table_check.h | 11 +++++++----
include/linux/pgtable.h | 2 +-
mm/page_table_check.c | 5 +++--
6 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 72ccbd810b13..db8bab350a2d 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1394,7 +1394,7 @@ static inline pte_t __ptep_get_and_clear_anysz(struct mm_struct *mm,
page_table_check_pte_clear(mm, pte);
break;
case PMD_SIZE:
- page_table_check_pmd_clear(mm, pte_pmd(pte));
+ page_table_check_pmd_clear(mm, address, pte_pmd(pte));
break;
#ifndef __PAGETABLE_PMD_FOLDED
case PUD_SIZE:
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 7b292af35f4b..cc3c690f6c93 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -877,7 +877,7 @@ static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
{
pmd_t pmd = __pmd(atomic_long_xchg((atomic_long_t *)pmdp, 0));

- page_table_check_pmd_clear(mm, pmd);
+ page_table_check_pmd_clear(mm, address, pmd);

return pmd;
}
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 4d6da32e77a6..50d76a38ab9f 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1365,7 +1365,7 @@ static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, unsigned long
{
pmd_t pmd = native_pmdp_get_and_clear(pmdp);

- page_table_check_pmd_clear(mm, pmd);
+ page_table_check_pmd_clear(mm, addr, pmd);

return pmd;
}
diff --git a/include/linux/page_table_check.h b/include/linux/page_table_check.h
index 808cc3a48c28..3973b69ae294 100644
--- a/include/linux/page_table_check.h
+++ b/include/linux/page_table_check.h
@@ -15,7 +15,8 @@ extern struct page_ext_operations page_table_check_ops;

void __page_table_check_zero(struct page *page, unsigned int order);
void __page_table_check_pte_clear(struct mm_struct *mm, pte_t pte);
-void __page_table_check_pmd_clear(struct mm_struct *mm, pmd_t pmd);
+void __page_table_check_pmd_clear(struct mm_struct *mm, unsigned long addr,
+ pmd_t pmd);
void __page_table_check_pud_clear(struct mm_struct *mm, unsigned long addr,
pud_t pud);
void __page_table_check_ptes_set(struct mm_struct *mm, unsigned long addr,
@@ -52,12 +53,13 @@ static inline void page_table_check_pte_clear(struct mm_struct *mm, pte_t pte)
__page_table_check_pte_clear(mm, pte);
}

-static inline void page_table_check_pmd_clear(struct mm_struct *mm, pmd_t pmd)
+static inline void page_table_check_pmd_clear(struct mm_struct *mm,
+ unsigned long addr, pmd_t pmd)
{
if (static_branch_likely(&page_table_check_disabled))
return;

- __page_table_check_pmd_clear(mm, pmd);
+ __page_table_check_pmd_clear(mm, addr, pmd);
}

static inline void page_table_check_pud_clear(struct mm_struct *mm,
@@ -121,7 +123,8 @@ static inline void page_table_check_pte_clear(struct mm_struct *mm, pte_t pte)
{
}

-static inline void page_table_check_pmd_clear(struct mm_struct *mm, pmd_t pmd)
+static inline void page_table_check_pmd_clear(struct mm_struct *mm,
+ unsigned long addr, pmd_t pmd)
{
}

diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 765451864de3..13e9336bf20e 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -637,7 +637,7 @@ static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
pmd_t pmd = *pmdp;

pmd_clear(pmdp);
- page_table_check_pmd_clear(mm, pmd);
+ page_table_check_pmd_clear(mm, address, pmd);

return pmd;
}
diff --git a/mm/page_table_check.c b/mm/page_table_check.c
index bd1242087a35..e8c26b616aed 100644
--- a/mm/page_table_check.c
+++ b/mm/page_table_check.c
@@ -156,7 +156,8 @@ void __page_table_check_pte_clear(struct mm_struct *mm, pte_t pte)
}
EXPORT_SYMBOL(__page_table_check_pte_clear);

-void __page_table_check_pmd_clear(struct mm_struct *mm, pmd_t pmd)
+void __page_table_check_pmd_clear(struct mm_struct *mm, unsigned long addr,
+ pmd_t pmd)
{
if (&init_mm == mm)
return;
@@ -231,7 +232,7 @@ void __page_table_check_pmds_set(struct mm_struct *mm, unsigned long addr,
page_table_check_pmd_flags(pmd);

for (i = 0; i < nr; i++)
- __page_table_check_pmd_clear(mm, *(pmdp + i));
+ __page_table_check_pmd_clear(mm, addr + PMD_SIZE * i, *(pmdp + i));
if (pmd_user_accessible_page(pmd))
page_table_check_set(pmd_pfn(pmd), stride * nr, pmd_write(pmd));
}
--
2.49.0