Re: [PATCH v16 07/13] mm/page_table_check: Reinstate address parameter in [__]page_table_check_pmd_clear()

From: Rohan McLure <redacted>

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@linux.ibm.com: rebase on arm64 changes]
Signed-off-by: Rohan McLure <redacted>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Ingo Molnar <mingo@kernel.org>  # x86
Signed-off-by: Andrew Donnellan <redacted>
---
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 81f06e5e32b2..dfcdf051b114 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h

@@ -1370,7 +1370,7 @@ 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 2484c0788012..d11fc6333606 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h

@@ -860,7 +860,7 @@ 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 8b45e0c41923..b68bea15f32d 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h

@@ -1318,7 +1318,7 @@ 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 28fcff844b63..d97f40f1365d 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h

@@ -648,7 +648,7 @@ 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));
  }