Re: [PATCH v16 08/13] mm/page_table_check: Reinstate address parameter in [__]page_table_check_pte_clear()

From: Rohan McLure <redacted>

This reverts commit aa232204c468 ("mm/page_table_check: remove unused
parameter in [__]page_table_check_pte_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, fix additional occurrence and loop handling]
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>
---
v13: fix an additional occurrence
v15: rebase, fix loop handling
---
  arch/arm64/include/asm/pgtable.h |  2 +-
  arch/riscv/include/asm/pgtable.h |  2 +-
  arch/x86/include/asm/pgtable.h   |  4 ++--
  include/linux/page_table_check.h | 11 +++++++----
  include/linux/pgtable.h          |  4 ++--
  mm/page_table_check.c            |  7 ++++---
  6 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index dfcdf051b114..2203ebac81d9 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h

@@ -1367,7 +1367,7 @@ static inline pte_t __ptep_get_and_clear_anysz(struct mm_struct *mm,
  
  	switch (pgsize) {
  	case PAGE_SIZE:
-		page_table_check_pte_clear(mm, pte);
+		page_table_check_pte_clear(mm, address, pte);
  		break;
  	case PMD_SIZE:
  		page_table_check_pmd_clear(mm, address, pte_pmd(pte));

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index d11fc6333606..d60e1604852d 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h

@@ -591,7 +591,7 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
  {
  	pte_t pte = __pte(atomic_long_xchg((atomic_long_t *)ptep, 0));
  
-	page_table_check_pte_clear(mm, pte);
+	page_table_check_pte_clear(mm, address, pte);
  
  	return pte;
  }

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index b68bea15f32d..63350b76c0c6 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h

@@ -1251,7 +1251,7 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
  				       pte_t *ptep)
  {
  	pte_t pte = native_ptep_get_and_clear(ptep);
-	page_table_check_pte_clear(mm, pte);
+	page_table_check_pte_clear(mm, addr, pte);
  	return pte;
  }
  

@@ -1267,7 +1267,7 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
  		 * care about updates and native needs no locking
  		 */
  		pte = native_local_ptep_get_and_clear(ptep);
-		page_table_check_pte_clear(mm, pte);
+		page_table_check_pte_clear(mm, addr, pte);
  	} else {
  		pte = ptep_get_and_clear(mm, addr, ptep);
  	}

diff --git a/include/linux/page_table_check.h b/include/linux/page_table_check.h
index 3973b69ae294..12268a32e8be 100644
--- a/include/linux/page_table_check.h
+++ b/include/linux/page_table_check.h

@@ -14,7 +14,8 @@ extern struct static_key_true page_table_check_disabled;
  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_pte_clear(struct mm_struct *mm, unsigned long addr,
+				  pte_t pte);
  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,

@@ -45,12 +46,13 @@ static inline void page_table_check_free(struct page *page, unsigned int order)
  	__page_table_check_zero(page, order);
  }
  
-static inline void page_table_check_pte_clear(struct mm_struct *mm, pte_t pte)
+static inline void page_table_check_pte_clear(struct mm_struct *mm,
+					      unsigned long addr, pte_t pte)
  {
  	if (static_branch_likely(&page_table_check_disabled))
  		return;
  
-	__page_table_check_pte_clear(mm, pte);
+	__page_table_check_pte_clear(mm, addr, pte);
  }
  
  static inline void page_table_check_pmd_clear(struct mm_struct *mm,

@@ -119,7 +121,8 @@ static inline void page_table_check_free(struct page *page, unsigned int order)
  {
  }
  
-static inline void page_table_check_pte_clear(struct mm_struct *mm, pte_t pte)
+static inline void page_table_check_pte_clear(struct mm_struct *mm,
+					      unsigned long addr, pte_t pte)
  {
  }
  

diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index d97f40f1365d..c85e0e1c1f97 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h

@@ -494,7 +494,7 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
  {
  	pte_t pte = ptep_get(ptep);
  	pte_clear(mm, address, ptep);
-	page_table_check_pte_clear(mm, pte);
+	page_table_check_pte_clear(mm, address, pte);
  	return pte;
  }
  #endif

@@ -553,7 +553,7 @@ static inline void ptep_clear(struct mm_struct *mm, unsigned long addr,
  	 * No need for ptep_get_and_clear(): page table check doesn't care about
  	 * any bits that could have been set by HW concurrently.
  	 */
-	page_table_check_pte_clear(mm, pte);
+	page_table_check_pte_clear(mm, addr, pte);
  }
  
  #ifdef CONFIG_GUP_GET_PXX_LOW_HIGH

diff --git a/mm/page_table_check.c b/mm/page_table_check.c
index e8c26b616aed..1c33439b9c0b 100644
--- a/mm/page_table_check.c
+++ b/mm/page_table_check.c

@@ -145,7 +145,8 @@ void __page_table_check_zero(struct page *page, unsigned int order)
  	rcu_read_unlock();
  }
  
-void __page_table_check_pte_clear(struct mm_struct *mm, pte_t pte)
+void __page_table_check_pte_clear(struct mm_struct *mm, unsigned long addr,
+				  pte_t pte)
  {
  	if (&init_mm == mm)
  		return;

@@ -206,7 +207,7 @@ void __page_table_check_ptes_set(struct mm_struct *mm, unsigned long addr,
  	page_table_check_pte_flags(pte);
  
  	for (i = 0; i < nr; i++)
-		__page_table_check_pte_clear(mm, ptep_get(ptep + i));
+		__page_table_check_pte_clear(mm, addr + PAGE_SIZE * i, ptep_get(ptep + i));
  	if (pte_user_accessible_page(pte))
  		page_table_check_set(pte_pfn(pte), nr, pte_write(pte));
  }

@@ -268,7 +269,7 @@ void __page_table_check_pte_clear_range(struct mm_struct *mm,
  		if (WARN_ON(!ptep))
  			return;
  		for (i = 0; i < PTRS_PER_PTE; i++) {
-			__page_table_check_pte_clear(mm, ptep_get(ptep));
+			__page_table_check_pte_clear(mm, addr, ptep_get(ptep));
  			addr += PAGE_SIZE;
  			ptep++;
  		}