[PATCH v15 00/13] Support page table check on PowerPC

[PATCH v15 00/13] Support page table check on PowerPC

[Andrew Donnellan]

Support page table check on all PowerPC platforms. This works by
serialising assignments, reassignments and clears of page table
entries at each level in order to ensure that anonymous mappings
have at most one writable consumer, and likewise that file-backed
mappings are not simultaneously also anonymous mappings.

In order to support this infrastructure, a number of stubs must be
defined for all powerpc platforms. Additionally, separate set_pte_at()
and set_pte_at_unchecked(), to allow for internal, uninstrumented mappings.

On some PowerPC platforms, implementing {pte,pmd,pud}_user_accessible_page()
requires the address. We revert previous changes that removed the address
parameter from various interfaces, and add it to some other interfaces,
in order to allow this.

(This series was initially written by Rohan McLure, who has left IBM and
is no longer working on powerpc.)

v15:
 * Rebase on mainline, including commit 91e40668e70a
   ("mm/page_table_check: Batch-check pmds/puds just like ptes") and
   associated arm64 changes
 * Clarify/fix some commit messages
 * Fix handling of address in a loop in __page_table_check_ptes_set()

v14:
 * Fix a call to page_table_check_pud_set() that was missed (akpm)
Link: https://lore.kernel.org/all/20250411054354.511145-1-ajd@linux.ibm.com/

v13:
 * Rebase on mainline
 * Don't use set_pte_at_unchecked() for early boot purposes (Pasha)
Link: https://lore.kernel.org/linuxppc-dev/20250211161404.850215-1-ajd@linux.ibm.com/

v12:
 * Rename commits that revert changes to instead reflect that we are
   reinstating old behaviour due to it providing more flexibility
 * Add return line to pud_pfn() stub
 * Instrument ptep_get_and_clear() for nohash
Link: https://lore.kernel.org/linuxppc-dev/20240402051154.476244-1-rmclure@linux.ibm.com/

v11:
 * The pud_pfn() stub, which previously had no legitimate users on any
   powerpc platform, now has users in Book3s64 with transparent pages.
   Include a stub of the same name for each platform that does not
   define their own.
 * Drop patch that standardised use of p*d_leaf(), as already included
   upstream in v6.9.
 * Provide fallback definitions of p{m,u}d_user_accessible_page() that
   do not reference p*d_leaf(), p*d_pte(), as they are defined after
   powerpc/mm headers by linux/mm headers.
 * Ensure that set_pte_at_unchecked() has the same checks as
   set_pte_at().
Link: https://lore.kernel.org/linuxppc-dev/20240328045535.194800-14-rmclure@linux.ibm.com/ 

v10:
 * Revert patches that removed address and mm parameters from page table
   check routines, including consuming code from arm64, x86_64 and
   riscv.
 * Implement *_user_accessible_page() routines in terms of pte_user()
   where available (64-bit, book3s) but otherwise by checking the
   address (on platforms where the pte does not imply whether the
   mapping is for user or kernel)
 * Internal set_pte_at() calls replaced with set_pte_at_unchecked(), which
   is identical, but prevents double instrumentation.
Link: https://lore.kernel.org/linuxppc-dev/20240313042118.230397-9-rmclure@linux.ibm.com/T/

v9:
 * Adapt to using the set_ptes() API, using __set_pte_at() where we need
   must avoid instrumentation.
 * Use the logic of *_access_permitted() for implementing
   *_user_accessible_page(), which are required routines for page table
   check.
 * Even though we no longer need p{m,u,4}d_leaf(), still default
   implement these to assist in refactoring out extant
   p{m,u,4}_is_leaf().
 * Add p{m,u}_pte() stubs where asm-generic does not provide them, as
   page table check wants all *user_accessible_page() variants, and we
   would like to default implement the variants in terms of
   pte_user_accessible_page().
 * Avoid the ugly pmdp_collapse_flush() macro nonsense! Just instrument
   its constituent calls instead for radix and hash.
Link: https://lore.kernel.org/linuxppc-dev/20231130025404.37179-2-rmclure@linux.ibm.com/

v8:
 * Fix linux/page_table_check.h include in asm/pgtable.h breaking
   32-bit.
Link: https://lore.kernel.org/linuxppc-dev/20230215231153.2147454-1-rmclure@linux.ibm.com/

v7:
 * Remove use of extern in set_pte prototypes
 * Clean up pmdp_collapse_flush macro
 * Replace set_pte_at with static inline function
 * Fix commit message for patch 7
Link: https://lore.kernel.org/linuxppc-dev/20230215020155.1969194-1-rmclure@linux.ibm.com/

v6:
 * Support huge pages and p{m,u}d accounting.
 * Remove instrumentation from set_pte from kernel internal pages.
 * 64s: Implement pmdp_collapse_flush in terms of __pmdp_collapse_flush
   as access to the mm_struct * is required.
Link: https://lore.kernel.org/linuxppc-dev/20230214015939.1853438-1-rmclure@linux.ibm.com/

v5:
Link: https://lore.kernel.org/linuxppc-dev/20221118002146.25979-1-rmclure@linux.ibm.com/

Andrew Donnellan (2):
  arm64/mm: Add addr parameter to __set_{ptes_anysz,ptes,pmds,puds}()
  arm64/mm: Add addr parameter to __ptep_get_and_clear_anysz()

Rohan McLure (11):
  mm/page_table_check: Reinstate address parameter in
    [__]page_table_check_pud[s]_set()
  mm/page_table_check: Reinstate address parameter in
    [__]page_table_check_pmd[s]_set()
  mm/page_table_check: Provide addr parameter to
    [__]page_table_check_ptes_set()
  mm/page_table_check: Reinstate address parameter in
    [__]page_table_check_pud_clear()
  mm/page_table_check: Reinstate address parameter in
    [__]page_table_check_pmd_clear()
  mm/page_table_check: Reinstate address parameter in
    [__]page_table_check_pte_clear()
  mm: Provide address parameter to p{te,md,ud}_user_accessible_page()
  powerpc: mm: Add pud_pfn() stub
  powerpc: mm: Implement *_user_accessible_page() for ptes
  powerpc: mm: Use set_pte_at_unchecked() for internal usages
  powerpc: mm: Support page table check

 arch/arm64/include/asm/pgtable.h             | 46 ++++++-------
 arch/arm64/mm/hugetlbpage.c                  | 15 +++--
 arch/powerpc/Kconfig                         |  1 +
 arch/powerpc/include/asm/book3s/32/pgtable.h | 12 +++-
 arch/powerpc/include/asm/book3s/64/pgtable.h | 62 +++++++++++++++---
 arch/powerpc/include/asm/nohash/pgtable.h    | 13 +++-
 arch/powerpc/include/asm/pgtable.h           | 19 ++++++
 arch/powerpc/mm/book3s64/hash_pgtable.c      |  4 ++
 arch/powerpc/mm/book3s64/pgtable.c           | 17 +++--
 arch/powerpc/mm/book3s64/radix_pgtable.c     |  9 ++-
 arch/powerpc/mm/pgtable.c                    | 12 ++++
 arch/riscv/include/asm/pgtable.h             | 20 +++---
 arch/x86/include/asm/pgtable.h               | 22 +++----
 include/linux/page_table_check.h             | 69 ++++++++++++--------
 include/linux/pgtable.h                      | 10 +--
 mm/page_table_check.c                        | 41 ++++++------
 16 files changed, 247 insertions(+), 125 deletions(-)

-- 
2.49.0

[PATCH v15 01/13] arm64/mm: Add addr parameter to __set_{ptes_anysz,ptes,pmds,puds}()

[Andrew Donnellan]

To provide support for page table check on powerpc, we need to reinstate the
address parameter in several functions, including
page_table_check_{ptes,pmds,puds}_set().

In preparation for this, add the addr parameter to arm64's __set_ptes_anysz()
and its callers, __set_ptes(), __set_pmds() and __set_puds(). While this
parameter won't (at present) be used on arm64, this will keep the usage of
the page table check interfaces consistent.

Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
---
v15: new patch
---
 arch/arm64/include/asm/pgtable.h | 19 ++++++++-----------
 arch/arm64/mm/hugetlbpage.c      |  8 ++++----
 2 files changed, 12 insertions(+), 15 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 192d86e1cc76..acbcb5e883ce 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -712,8 +712,8 @@ static inline pgprot_t pud_pgprot(pud_t pud)
 	return __pgprot(pud_val(pfn_pud(pfn, __pgprot(0))) ^ pud_val(pud));
 }
 
-static inline void __set_ptes_anysz(struct mm_struct *mm, pte_t *ptep,
-				    pte_t pte, unsigned int nr,
+static inline void __set_ptes_anysz(struct mm_struct *mm, unsigned long addr,
+				    pte_t *ptep, pte_t pte, unsigned int nr,
 				    unsigned long pgsize)
 {
 	unsigned long stride = pgsize >> PAGE_SHIFT;
@@ -748,26 +748,23 @@ static inline void __set_ptes_anysz(struct mm_struct *mm, pte_t *ptep,
 	__set_pte_complete(pte);
 }
 
-static inline void __set_ptes(struct mm_struct *mm,
-			      unsigned long __always_unused addr,
+static inline void __set_ptes(struct mm_struct *mm, unsigned long addr,
 			      pte_t *ptep, pte_t pte, unsigned int nr)
 {
-	__set_ptes_anysz(mm, ptep, pte, nr, PAGE_SIZE);
+	__set_ptes_anysz(mm, addr, ptep, pte, nr, PAGE_SIZE);
 }
 
-static inline void __set_pmds(struct mm_struct *mm,
-			      unsigned long __always_unused addr,
+static inline void __set_pmds(struct mm_struct *mm, unsigned long addr,
 			      pmd_t *pmdp, pmd_t pmd, unsigned int nr)
 {
-	__set_ptes_anysz(mm, (pte_t *)pmdp, pmd_pte(pmd), nr, PMD_SIZE);
+	__set_ptes_anysz(mm, addr, (pte_t *)pmdp, pmd_pte(pmd), nr, PMD_SIZE);
 }
 #define set_pmd_at(mm, addr, pmdp, pmd) __set_pmds(mm, addr, pmdp, pmd, 1)
 
-static inline void __set_puds(struct mm_struct *mm,
-			      unsigned long __always_unused addr,
+static inline void __set_puds(struct mm_struct *mm, unsigned long addr,
 			      pud_t *pudp, pud_t pud, unsigned int nr)
 {
-	__set_ptes_anysz(mm, (pte_t *)pudp, pud_pte(pud), nr, PUD_SIZE);
+	__set_ptes_anysz(mm, addr, (pte_t *)pudp, pud_pte(pud), nr, PUD_SIZE);
 }
 #define set_pud_at(mm, addr, pudp, pud) __set_puds(mm, addr, pudp, pud, 1)
 
diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index 0c8737f4f2ce..1003b5020752 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -226,7 +226,7 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 
 	if (!pte_present(pte)) {
 		for (i = 0; i < ncontig; i++, ptep++, addr += pgsize)
-			__set_ptes_anysz(mm, ptep, pte, 1, pgsize);
+			__set_ptes_anysz(mm, addr, ptep, pte, 1, pgsize);
 		return;
 	}
 
@@ -234,7 +234,7 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 	if (pte_cont(pte) && pte_valid(__ptep_get(ptep)))
 		clear_flush(mm, addr, ptep, pgsize, ncontig);
 
-	__set_ptes_anysz(mm, ptep, pte, ncontig, pgsize);
+	__set_ptes_anysz(mm, addr, ptep, pte, ncontig, pgsize);
 }
 
 pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
@@ -449,7 +449,7 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma,
 	if (pte_young(orig_pte))
 		pte = pte_mkyoung(pte);
 
-	__set_ptes_anysz(mm, ptep, pte, ncontig, pgsize);
+	__set_ptes_anysz(mm, addr, ptep, pte, ncontig, pgsize);
 	return 1;
 }
 
@@ -473,7 +473,7 @@ void huge_ptep_set_wrprotect(struct mm_struct *mm,
 	pte = get_clear_contig_flush(mm, addr, ptep, pgsize, ncontig);
 	pte = pte_wrprotect(pte);
 
-	__set_ptes_anysz(mm, ptep, pte, ncontig, pgsize);
+	__set_ptes_anysz(mm, addr, ptep, pte, ncontig, pgsize);
 }
 
 pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
-- 
2.49.0

[PATCH v15 02/13] arm64/mm: Add addr parameter to __ptep_get_and_clear_anysz()

[Andrew Donnellan]

To provide support for page table check on powerpc, we need to reinstate the
address parameter in several functions, including
page_table_check_{pte,pmd,pud}_clear().

In preparation for this, add the addr parameter to arm64's
__ptep_get_and_clear_anysz() and change its callsites accordingly. While this
parameter won't (at present) be used on arm64, this will keep the usage of
the page table check interfaces consistent.

Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
---
v15: new patch
---
 arch/arm64/include/asm/pgtable.h | 5 +++--
 arch/arm64/mm/hugetlbpage.c      | 7 ++++---
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index acbcb5e883ce..75572a08c012 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1381,6 +1381,7 @@ static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG */
 
 static inline pte_t __ptep_get_and_clear_anysz(struct mm_struct *mm,
+					       unsigned long address,
 					       pte_t *ptep,
 					       unsigned long pgsize)
 {
@@ -1408,7 +1409,7 @@ static inline pte_t __ptep_get_and_clear_anysz(struct mm_struct *mm,
 static inline pte_t __ptep_get_and_clear(struct mm_struct *mm,
 				       unsigned long address, pte_t *ptep)
 {
-	return __ptep_get_and_clear_anysz(mm, ptep, PAGE_SIZE);
+	return __ptep_get_and_clear_anysz(mm, address, ptep, PAGE_SIZE);
 }
 
 static inline void __clear_full_ptes(struct mm_struct *mm, unsigned long addr,
@@ -1447,7 +1448,7 @@ static inline pte_t __get_and_clear_full_ptes(struct mm_struct *mm,
 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
 					    unsigned long address, pmd_t *pmdp)
 {
-	return pte_pmd(__ptep_get_and_clear_anysz(mm, (pte_t *)pmdp, PMD_SIZE));
+	return pte_pmd(__ptep_get_and_clear_anysz(mm, address, (pte_t *)pmdp, PMD_SIZE));
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index 1003b5020752..bcc28031eb7a 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -159,11 +159,12 @@ static pte_t get_clear_contig(struct mm_struct *mm,
 	pte_t pte, tmp_pte;
 	bool present;
 
-	pte = __ptep_get_and_clear_anysz(mm, ptep, pgsize);
+	pte = __ptep_get_and_clear_anysz(mm, addr, ptep, pgsize);
 	present = pte_present(pte);
 	while (--ncontig) {
 		ptep++;
-		tmp_pte = __ptep_get_and_clear_anysz(mm, ptep, pgsize);
+		addr += pgsize;
+		tmp_pte = __ptep_get_and_clear_anysz(mm, addr, ptep, pgsize);
 		if (present) {
 			if (pte_dirty(tmp_pte))
 				pte = pte_mkdirty(pte);
@@ -207,7 +208,7 @@ static void clear_flush(struct mm_struct *mm,
 	unsigned long i, saddr = addr;
 
 	for (i = 0; i < ncontig; i++, addr += pgsize, ptep++)
-		__ptep_get_and_clear_anysz(mm, ptep, pgsize);
+		__ptep_get_and_clear_anysz(mm, addr, ptep, pgsize);
 
 	if (mm == &init_mm)
 		flush_tlb_kernel_range(saddr, addr);
-- 
2.49.0

[PATCH v15 03/13] mm/page_table_check: Reinstate address parameter in [__]page_table_check_pud[s]_set()

[Andrew Donnellan]

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

This reverts commit 6d144436d954 ("mm/page_table_check: remove unused
parameter in [__]page_table_check_pud_set").

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.

Apply this to __page_table_check_puds_set(), page_table_check_puds_set() and
the page_table_check_pud_set() wrapper macro.

[ajd@linux.ibm.com: rebase on riscv + arm64 changes, update commit message]
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
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
---
v13: remove inaccurate comment on riscv in the commit message
v14: fix an x86 usage I missed (found by akpm)
v15: rebase, amend commit message
---
 arch/arm64/include/asm/pgtable.h |  3 ++-
 arch/riscv/include/asm/pgtable.h |  4 ++--
 arch/x86/include/asm/pgtable.h   |  4 ++--
 include/linux/page_table_check.h | 12 ++++++------
 mm/page_table_check.c            |  4 ++--
 5 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 75572a08c012..be463058207c 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -727,7 +727,8 @@ static inline void __set_ptes_anysz(struct mm_struct *mm, unsigned long addr,
 		break;
 #ifndef __PAGETABLE_PMD_FOLDED
 	case PUD_SIZE:
-		page_table_check_puds_set(mm, (pud_t *)ptep, pte_pud(pte), nr);
+		page_table_check_puds_set(mm, addr, (pud_t *)ptep,
+					  pte_pud(pte), nr);
 		break;
 #endif
 	default:
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 438ce7df24c3..8142b7c48295 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -829,7 +829,7 @@ static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
 				pud_t *pudp, pud_t pud)
 {
-	page_table_check_pud_set(mm, pudp, pud);
+	page_table_check_pud_set(mm, addr, pudp, pud);
 	return __set_pte_at(mm, (pte_t *)pudp, pud_pte(pud));
 }
 
@@ -980,7 +980,7 @@ static inline void update_mmu_cache_pud(struct vm_area_struct *vma,
 static inline pud_t pudp_establish(struct vm_area_struct *vma,
 				   unsigned long address, pud_t *pudp, pud_t pud)
 {
-	page_table_check_pud_set(vma->vm_mm, pudp, pud);
+	page_table_check_pud_set(vma->vm_mm, address, pudp, pud);
 	return __pud(atomic_long_xchg((atomic_long_t *)pudp, pud_val(pud)));
 }
 
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 97954c936c54..ab10efb392d1 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1267,7 +1267,7 @@ static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
 			      pud_t *pudp, pud_t pud)
 {
-	page_table_check_pud_set(mm, pudp, pud);
+	page_table_check_pud_set(mm, addr, pudp, pud);
 	native_set_pud(pudp, pud);
 }
 
@@ -1418,7 +1418,7 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
 static inline pud_t pudp_establish(struct vm_area_struct *vma,
 		unsigned long address, pud_t *pudp, pud_t pud)
 {
-	page_table_check_pud_set(vma->vm_mm, pudp, pud);
+	page_table_check_pud_set(vma->vm_mm, address, pudp, pud);
 	if (IS_ENABLED(CONFIG_SMP)) {
 		return xchg(pudp, pud);
 	} else {
diff --git a/include/linux/page_table_check.h b/include/linux/page_table_check.h
index 289620d4aad3..0bf18b884a12 100644
--- a/include/linux/page_table_check.h
+++ b/include/linux/page_table_check.h
@@ -21,8 +21,8 @@ void __page_table_check_ptes_set(struct mm_struct *mm, pte_t *ptep, pte_t pte,
 		unsigned int nr);
 void __page_table_check_pmds_set(struct mm_struct *mm, pmd_t *pmdp, pmd_t pmd,
 		unsigned int nr);
-void __page_table_check_puds_set(struct mm_struct *mm, pud_t *pudp, pud_t pud,
-		unsigned int nr);
+void __page_table_check_puds_set(struct mm_struct *mm, unsigned long addr,
+		pud_t *pudp, pud_t pud, unsigned int nr);
 void __page_table_check_pte_clear_range(struct mm_struct *mm,
 					unsigned long addr,
 					pmd_t pmd);
@@ -86,12 +86,12 @@ static inline void page_table_check_pmds_set(struct mm_struct *mm,
 }
 
 static inline void page_table_check_puds_set(struct mm_struct *mm,
-		pud_t *pudp, pud_t pud, unsigned int nr)
+		unsigned long addr, pud_t *pudp, pud_t pud, unsigned int nr)
 {
 	if (static_branch_likely(&page_table_check_disabled))
 		return;
 
-	__page_table_check_puds_set(mm, pudp, pud, nr);
+	__page_table_check_puds_set(mm, addr, pudp, pud, nr);
 }
 
 static inline void page_table_check_pte_clear_range(struct mm_struct *mm,
@@ -137,7 +137,7 @@ static inline void page_table_check_pmds_set(struct mm_struct *mm,
 }
 
 static inline void page_table_check_puds_set(struct mm_struct *mm,
-		pud_t *pudp, pud_t pud, unsigned int nr)
+		unsigned long addr, pud_t *pudp, pud_t pud, unsigned int nr)
 {
 }
 
@@ -150,6 +150,6 @@ static inline void page_table_check_pte_clear_range(struct mm_struct *mm,
 #endif /* CONFIG_PAGE_TABLE_CHECK */
 
 #define page_table_check_pmd_set(mm, pmdp, pmd)	page_table_check_pmds_set(mm, pmdp, pmd, 1)
-#define page_table_check_pud_set(mm, pudp, pud)	page_table_check_puds_set(mm, pudp, pud, 1)
+#define page_table_check_pud_set(mm, addr, pudp, pud)	page_table_check_puds_set(mm, addr, pudp, pud, 1)
 
 #endif /* __LINUX_PAGE_TABLE_CHECK_H */
diff --git a/mm/page_table_check.c b/mm/page_table_check.c
index 4eeca782b888..3c39e4375886 100644
--- a/mm/page_table_check.c
+++ b/mm/page_table_check.c
@@ -236,8 +236,8 @@ void __page_table_check_pmds_set(struct mm_struct *mm, pmd_t *pmdp, pmd_t pmd,
 }
 EXPORT_SYMBOL(__page_table_check_pmds_set);
 
-void __page_table_check_puds_set(struct mm_struct *mm, pud_t *pudp, pud_t pud,
-		unsigned int nr)
+void __page_table_check_puds_set(struct mm_struct *mm, unsigned long addr,
+		pud_t *pudp, pud_t pud,	unsigned int nr)
 {
 	unsigned long stride = PUD_SIZE >> PAGE_SHIFT;
 	unsigned int i;
-- 
2.49.0

[PATCH v15 04/13] mm/page_table_check: Reinstate address parameter in [__]page_table_check_pmd[s]_set()

[Andrew Donnellan]

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

This reverts commit a3b837130b58 ("mm/page_table_check: remove unused
parameter in [__]page_table_check_pmd_set").

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.

Apply this to __page_table_check_pmds_set(), page_table_check_pmd_set(), and
the page_table_check_pmd_set() wrapper macro.

[ajd@linux.ibm.com: rebase on arm64 + riscv changes, update commit message]
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
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
---
v13: remove inaccurate comment on riscv in the commit message
v14: rebase
v15: rebase, amend commit message
---
 arch/arm64/include/asm/pgtable.h |  5 +++--
 arch/riscv/include/asm/pgtable.h |  4 ++--
 arch/x86/include/asm/pgtable.h   |  4 ++--
 include/linux/page_table_check.h | 12 ++++++------
 mm/page_table_check.c            |  4 ++--
 5 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index be463058207c..0d34157106ee 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -723,7 +723,8 @@ static inline void __set_ptes_anysz(struct mm_struct *mm, unsigned long addr,
 		page_table_check_ptes_set(mm, ptep, pte, nr);
 		break;
 	case PMD_SIZE:
-		page_table_check_pmds_set(mm, (pmd_t *)ptep, pte_pmd(pte), nr);
+		page_table_check_pmds_set(mm, addr, (pmd_t *)ptep,
+					  pte_pmd(pte), nr);
 		break;
 #ifndef __PAGETABLE_PMD_FOLDED
 	case PUD_SIZE:
@@ -1538,7 +1539,7 @@ static inline void pmdp_set_wrprotect(struct mm_struct *mm,
 static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
 		unsigned long address, pmd_t *pmdp, pmd_t pmd)
 {
-	page_table_check_pmd_set(vma->vm_mm, pmdp, pmd);
+	page_table_check_pmd_set(vma->vm_mm, address, pmdp, pmd);
 	return __pmd(xchg_relaxed(&pmd_val(*pmdp), pmd_val(pmd)));
 }
 #endif
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 8142b7c48295..62778ccdcf52 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -822,7 +822,7 @@ static inline pud_t pud_mkspecial(pud_t pud)
 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 				pmd_t *pmdp, pmd_t pmd)
 {
-	page_table_check_pmd_set(mm, pmdp, pmd);
+	page_table_check_pmd_set(mm, addr, pmdp, pmd);
 	return __set_pte_at(mm, (pte_t *)pmdp, pmd_pte(pmd));
 }
 
@@ -893,7 +893,7 @@ static inline void pmdp_set_wrprotect(struct mm_struct *mm,
 static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
 				unsigned long address, pmd_t *pmdp, pmd_t pmd)
 {
-	page_table_check_pmd_set(vma->vm_mm, pmdp, pmd);
+	page_table_check_pmd_set(vma->vm_mm, address, pmdp, pmd);
 	return __pmd(atomic_long_xchg((atomic_long_t *)pmdp, pmd_val(pmd)));
 }
 
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index ab10efb392d1..995ca7e6e0e9 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1260,7 +1260,7 @@ static inline pud_t native_local_pudp_get_and_clear(pud_t *pudp)
 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 			      pmd_t *pmdp, pmd_t pmd)
 {
-	page_table_check_pmd_set(mm, pmdp, pmd);
+	page_table_check_pmd_set(mm, addr, pmdp, pmd);
 	set_pmd(pmdp, pmd);
 }
 
@@ -1403,7 +1403,7 @@ static inline void pmdp_set_wrprotect(struct mm_struct *mm,
 static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
 		unsigned long address, pmd_t *pmdp, pmd_t pmd)
 {
-	page_table_check_pmd_set(vma->vm_mm, pmdp, pmd);
+	page_table_check_pmd_set(vma->vm_mm, address, pmdp, pmd);
 	if (IS_ENABLED(CONFIG_SMP)) {
 		return xchg(pmdp, pmd);
 	} else {
diff --git a/include/linux/page_table_check.h b/include/linux/page_table_check.h
index 0bf18b884a12..cf7c28d8d468 100644
--- a/include/linux/page_table_check.h
+++ b/include/linux/page_table_check.h
@@ -19,8 +19,8 @@ void __page_table_check_pmd_clear(struct mm_struct *mm, pmd_t pmd);
 void __page_table_check_pud_clear(struct mm_struct *mm, pud_t pud);
 void __page_table_check_ptes_set(struct mm_struct *mm, pte_t *ptep, pte_t pte,
 		unsigned int nr);
-void __page_table_check_pmds_set(struct mm_struct *mm, pmd_t *pmdp, pmd_t pmd,
-		unsigned int nr);
+void __page_table_check_pmds_set(struct mm_struct *mm, unsigned long addr,
+		pmd_t *pmdp, pmd_t pmd, unsigned int nr);
 void __page_table_check_puds_set(struct mm_struct *mm, unsigned long addr,
 		pud_t *pudp, pud_t pud, unsigned int nr);
 void __page_table_check_pte_clear_range(struct mm_struct *mm,
@@ -77,12 +77,12 @@ static inline void page_table_check_ptes_set(struct mm_struct *mm,
 }
 
 static inline void page_table_check_pmds_set(struct mm_struct *mm,
-		pmd_t *pmdp, pmd_t pmd, unsigned int nr)
+		unsigned long addr, pmd_t *pmdp, pmd_t pmd, unsigned int nr)
 {
 	if (static_branch_likely(&page_table_check_disabled))
 		return;
 
-	__page_table_check_pmds_set(mm, pmdp, pmd, nr);
+	__page_table_check_pmds_set(mm, addr, pmdp, pmd, nr);
 }
 
 static inline void page_table_check_puds_set(struct mm_struct *mm,
@@ -132,7 +132,7 @@ static inline void page_table_check_ptes_set(struct mm_struct *mm,
 }
 
 static inline void page_table_check_pmds_set(struct mm_struct *mm,
-		pmd_t *pmdp, pmd_t pmd, unsigned int nr)
+		unsigned long addr, pmd_t *pmdp, pmd_t pmd, unsigned int nr)
 {
 }
 
@@ -149,7 +149,7 @@ static inline void page_table_check_pte_clear_range(struct mm_struct *mm,
 
 #endif /* CONFIG_PAGE_TABLE_CHECK */
 
-#define page_table_check_pmd_set(mm, pmdp, pmd)	page_table_check_pmds_set(mm, pmdp, pmd, 1)
+#define page_table_check_pmd_set(mm, addr, pmdp, pmd)	page_table_check_pmds_set(mm, addr, pmdp, pmd, 1)
 #define page_table_check_pud_set(mm, addr, pudp, pud)	page_table_check_puds_set(mm, addr, pudp, pud, 1)
 
 #endif /* __LINUX_PAGE_TABLE_CHECK_H */
diff --git a/mm/page_table_check.c b/mm/page_table_check.c
index 3c39e4375886..09258f2ad93f 100644
--- a/mm/page_table_check.c
+++ b/mm/page_table_check.c
@@ -218,8 +218,8 @@ static inline void page_table_check_pmd_flags(pmd_t pmd)
 		WARN_ON_ONCE(swap_cached_writable(pmd_to_swp_entry(pmd)));
 }
 
-void __page_table_check_pmds_set(struct mm_struct *mm, pmd_t *pmdp, pmd_t pmd,
-		unsigned int nr)
+void __page_table_check_pmds_set(struct mm_struct *mm, unsigned long addr,
+		pmd_t *pmdp, pmd_t pmd, unsigned int nr)
 {
 	unsigned long stride = PMD_SIZE >> PAGE_SHIFT;
 	unsigned int i;
-- 
2.49.0

[PATCH v15 05/13] mm/page_table_check: Provide addr parameter to [__]page_table_check_ptes_set()

[Andrew Donnellan]

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

To provide support for powerpc platforms, provide an addr parameter to
the __page_table_check_ptes_set() and page_table_check_ptes_set() routines.
This parameter is needed on some powerpc platforms which do not encode whether
a mapping is for user or kernel in the pte. On such platforms, this can be
inferred from the addr parameter.

[ajd@linux.ibm.com: rebase on arm64 + riscv changes, update commit message]
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
---
v15: rebase, amend commit message
---
 arch/arm64/include/asm/pgtable.h |  2 +-
 arch/riscv/include/asm/pgtable.h |  2 +-
 include/linux/page_table_check.h | 12 +++++++-----
 include/linux/pgtable.h          |  2 +-
 mm/page_table_check.c            |  4 ++--
 5 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 0d34157106ee..383c01f9cae9 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -720,7 +720,7 @@ static inline void __set_ptes_anysz(struct mm_struct *mm, unsigned long addr,
 
 	switch (pgsize) {
 	case PAGE_SIZE:
-		page_table_check_ptes_set(mm, ptep, pte, nr);
+		page_table_check_ptes_set(mm, addr, ptep, pte, nr);
 		break;
 	case PMD_SIZE:
 		page_table_check_pmds_set(mm, addr, (pmd_t *)ptep,
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 62778ccdcf52..7b292af35f4b 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -572,7 +572,7 @@ static inline void __set_pte_at(struct mm_struct *mm, pte_t *ptep, pte_t pteval)
 static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
 		pte_t *ptep, pte_t pteval, unsigned int nr)
 {
-	page_table_check_ptes_set(mm, ptep, pteval, nr);
+	page_table_check_ptes_set(mm, addr, ptep, pteval, nr);
 
 	for (;;) {
 		__set_pte_at(mm, ptep, pteval);
diff --git a/include/linux/page_table_check.h b/include/linux/page_table_check.h
index cf7c28d8d468..66e109238416 100644
--- a/include/linux/page_table_check.h
+++ b/include/linux/page_table_check.h
@@ -17,8 +17,8 @@ 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_pud_clear(struct mm_struct *mm, pud_t pud);
-void __page_table_check_ptes_set(struct mm_struct *mm, pte_t *ptep, pte_t pte,
-		unsigned int nr);
+void __page_table_check_ptes_set(struct mm_struct *mm, unsigned long addr,
+		pte_t *ptep, pte_t pte, unsigned int nr);
 void __page_table_check_pmds_set(struct mm_struct *mm, unsigned long addr,
 		pmd_t *pmdp, pmd_t pmd, unsigned int nr);
 void __page_table_check_puds_set(struct mm_struct *mm, unsigned long addr,
@@ -68,12 +68,13 @@ static inline void page_table_check_pud_clear(struct mm_struct *mm, pud_t pud)
 }
 
 static inline void page_table_check_ptes_set(struct mm_struct *mm,
-		pte_t *ptep, pte_t pte, unsigned int nr)
+					     unsigned long addr, pte_t *ptep,
+					     pte_t pte, unsigned int nr)
 {
 	if (static_branch_likely(&page_table_check_disabled))
 		return;
 
-	__page_table_check_ptes_set(mm, ptep, pte, nr);
+	__page_table_check_ptes_set(mm, addr, ptep, pte, nr);
 }
 
 static inline void page_table_check_pmds_set(struct mm_struct *mm,
@@ -127,7 +128,8 @@ static inline void page_table_check_pud_clear(struct mm_struct *mm, pud_t pud)
 }
 
 static inline void page_table_check_ptes_set(struct mm_struct *mm,
-		pte_t *ptep, pte_t pte, unsigned int nr)
+					     unsigned long addr, pte_t *ptep,
+					     pte_t pte, unsigned int nr)
 {
 }
 
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 0b6e1f781d86..d06b5fec9540 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -289,7 +289,7 @@ static inline pte_t pte_advance_pfn(pte_t pte, unsigned long nr)
 static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
 		pte_t *ptep, pte_t pte, unsigned int nr)
 {
-	page_table_check_ptes_set(mm, ptep, pte, nr);
+	page_table_check_ptes_set(mm, addr, ptep, pte, nr);
 
 	for (;;) {
 		set_pte(ptep, pte);
diff --git a/mm/page_table_check.c b/mm/page_table_check.c
index 09258f2ad93f..0957767a2940 100644
--- a/mm/page_table_check.c
+++ b/mm/page_table_check.c
@@ -193,8 +193,8 @@ static inline void page_table_check_pte_flags(pte_t pte)
 		WARN_ON_ONCE(swap_cached_writable(pte_to_swp_entry(pte)));
 }
 
-void __page_table_check_ptes_set(struct mm_struct *mm, pte_t *ptep, pte_t pte,
-		unsigned int nr)
+void __page_table_check_ptes_set(struct mm_struct *mm, unsigned long addr,
+				 pte_t *ptep, pte_t pte, unsigned int nr)
 {
 	unsigned int i;
 
-- 
2.49.0

[PATCH v15 06/13] mm/page_table_check: Reinstate address parameter in [__]page_table_check_pud_clear()

[Andrew Donnellan]

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

This reverts commit 931c38e16499 ("mm/page_table_check: remove unused
parameter in [__]page_table_check_pud_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 <rmclure@linux.ibm.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Ingo Molnar <mingo@kernel.org>  # x86
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
---
v15: rebase
---
 arch/arm64/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 +++--
 5 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 383c01f9cae9..72ccbd810b13 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1398,7 +1398,7 @@ static inline pte_t __ptep_get_and_clear_anysz(struct mm_struct *mm,
 		break;
 #ifndef __PAGETABLE_PMD_FOLDED
 	case PUD_SIZE:
-		page_table_check_pud_clear(mm, pte_pud(pte));
+		page_table_check_pud_clear(mm, address, pte_pud(pte));
 		break;
 #endif
 	default:
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 995ca7e6e0e9..4d6da32e77a6 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1376,7 +1376,7 @@ static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm,
 {
 	pud_t pud = native_pudp_get_and_clear(pudp);
 
-	page_table_check_pud_clear(mm, pud);
+	page_table_check_pud_clear(mm, addr, pud);
 
 	return pud;
 }
diff --git a/include/linux/page_table_check.h b/include/linux/page_table_check.h
index 66e109238416..808cc3a48c28 100644
--- a/include/linux/page_table_check.h
+++ b/include/linux/page_table_check.h
@@ -16,7 +16,8 @@ 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_pud_clear(struct mm_struct *mm, pud_t pud);
+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,
 		pte_t *ptep, pte_t pte, unsigned int nr);
 void __page_table_check_pmds_set(struct mm_struct *mm, unsigned long addr,
@@ -59,12 +60,13 @@ static inline void page_table_check_pmd_clear(struct mm_struct *mm, pmd_t pmd)
 	__page_table_check_pmd_clear(mm, pmd);
 }
 
-static inline void page_table_check_pud_clear(struct mm_struct *mm, pud_t pud)
+static inline void page_table_check_pud_clear(struct mm_struct *mm,
+					      unsigned long addr, pud_t pud)
 {
 	if (static_branch_likely(&page_table_check_disabled))
 		return;
 
-	__page_table_check_pud_clear(mm, pud);
+	__page_table_check_pud_clear(mm, addr, pud);
 }
 
 static inline void page_table_check_ptes_set(struct mm_struct *mm,
@@ -123,7 +125,8 @@ static inline void page_table_check_pmd_clear(struct mm_struct *mm, pmd_t pmd)
 {
 }
 
-static inline void page_table_check_pud_clear(struct mm_struct *mm, pud_t pud)
+static inline void page_table_check_pud_clear(struct mm_struct *mm,
+					      unsigned long addr, pud_t pud)
 {
 }
 
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index d06b5fec9540..765451864de3 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -650,7 +650,7 @@ static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm,
 	pud_t pud = *pudp;
 
 	pud_clear(pudp);
-	page_table_check_pud_clear(mm, pud);
+	page_table_check_pud_clear(mm, address, pud);
 
 	return pud;
 }
diff --git a/mm/page_table_check.c b/mm/page_table_check.c
index 0957767a2940..bd1242087a35 100644
--- a/mm/page_table_check.c
+++ b/mm/page_table_check.c
@@ -167,7 +167,8 @@ void __page_table_check_pmd_clear(struct mm_struct *mm, pmd_t pmd)
 }
 EXPORT_SYMBOL(__page_table_check_pmd_clear);
 
-void __page_table_check_pud_clear(struct mm_struct *mm, pud_t pud)
+void __page_table_check_pud_clear(struct mm_struct *mm, unsigned long addr,
+				  pud_t pud)
 {
 	if (&init_mm == mm)
 		return;
@@ -246,7 +247,7 @@ void __page_table_check_puds_set(struct mm_struct *mm, unsigned long addr,
 		return;
 
 	for (i = 0; i < nr; i++)
-		__page_table_check_pud_clear(mm, *(pudp + i));
+		__page_table_check_pud_clear(mm, addr + PUD_SIZE * i, *(pudp + i));
 	if (pud_user_accessible_page(pud))
 		page_table_check_set(pud_pfn(pud), stride * nr, pud_write(pud));
 }
-- 
2.49.0

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

[Andrew Donnellan]

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

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 <rmclure@linux.ibm.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Ingo Molnar <mingo@kernel.org>  # x86
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
---
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

[PATCH v15 08/13] mm/page_table_check: Reinstate address parameter in [__]page_table_check_pte_clear()

[Andrew Donnellan]

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

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 <rmclure@linux.ibm.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Ingo Molnar <mingo@kernel.org>  # x86
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
---
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 db8bab350a2d..4dae6fd51792 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1391,7 +1391,7 @@ 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 cc3c690f6c93..99f8a05c595b 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -603,7 +603,7 @@ 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 50d76a38ab9f..8de92004f3fb 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1298,7 +1298,7 @@ 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;
 }
 
@@ -1314,7 +1314,7 @@ 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 13e9336bf20e..3e7c2e260279 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -483,7 +483,7 @@ 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
@@ -542,7 +542,7 @@ 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++;
 		}
-- 
2.49.0

[PATCH v15 09/13] mm: Provide address parameter to p{te,md,ud}_user_accessible_page()

[Andrew Donnellan]

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
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 4dae6fd51792..804606e4ef0e 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1314,17 +1314,17 @@ static inline int pgd_devmap(pgd_t pgd)
 #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 99f8a05c595b..29126d47cf8d 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -834,17 +834,17 @@ 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 8de92004f3fb..60523dd7f3a9 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1726,17 +1726,17 @@ 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 1c33439b9c0b..abc2232ceb39 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);
 	}
 }
@@ -208,7 +208,7 @@ 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);
@@ -234,7 +234,7 @@ 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);
@@ -250,7 +250,7 @@ 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);
-- 
2.49.0

[PATCH v15 10/13] powerpc: mm: Add pud_pfn() stub

[Andrew Donnellan]

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

The page table check feature requires that pud_pfn() be defined
on each consuming architecture.

On powerpc, only book3s64 platforms allow for hugepages at this upper
level, and thus only book3s64 currently defines pud_pfn().

The page table check code that calls pud_pfn() is gated by a call to
pud_user_accessible_page(), which will always return false on any platform
other than book3s64.

Add a stub implementation of pud_pfn() for all platforms other than
book3s64. As it will never actually be used and should always be compiled
out, raise a BUILD_BUG() error.

[ajd@linux.ibm.com: clarify commit message]
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
---
v15: clarify commit message
---
 arch/powerpc/include/asm/pgtable.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 93d77ad5a92f..0f73a9ade0ed 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -214,6 +214,15 @@ static inline bool arch_supports_memmap_on_memory(unsigned long vmemmap_size)
 
 #endif /* CONFIG_PPC64 */
 
+#ifndef pud_pfn
+#define pud_pfn pud_pfn
+static inline int pud_pfn(pud_t pud)
+{
+	BUILD_BUG();
+	return 0;
+}
+#endif
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_PGTABLE_H */
-- 
2.49.0

[PATCH v15 11/13] powerpc: mm: Implement *_user_accessible_page() for ptes

[Andrew Donnellan]

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

Page table checking depends on architectures providing an
implementation of p{te,md,ud}_user_accessible_page. With
refactorisations made on powerpc/mm, the pte_access_permitted() and
similar methods verify whether a userland page is accessible with the
required permissions.

Since page table checking is the only user of
p{te,md,ud}_user_accessible_page(), implement these for all platforms,
using some of the same preliminary checks taken by pte_access_permitted()
on that platform.

Since commit 8e9bd41e4ce1 ("powerpc/nohash: Replace pte_user() by pte_read()")
pte_user() is no longer required to be present on all platforms as it
may be equivalent to or implied by pte_read(). Hence implementations of
pte_user_accessible_page() are specialised.

[ajd@linux.ibm.com: rebase and fix commit message]
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
---
 arch/powerpc/include/asm/book3s/32/pgtable.h |  5 +++++
 arch/powerpc/include/asm/book3s/64/pgtable.h | 17 +++++++++++++++++
 arch/powerpc/include/asm/nohash/pgtable.h    |  5 +++++
 arch/powerpc/include/asm/pgtable.h           |  8 ++++++++
 4 files changed, 35 insertions(+)

diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h
index 92d21c6faf1e..b225967f85ea 100644
--- a/arch/powerpc/include/asm/book3s/32/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/32/pgtable.h
@@ -437,6 +437,11 @@ static inline bool pte_access_permitted(pte_t pte, bool write)
 	return true;
 }
 
+static inline bool pte_user_accessible_page(pte_t pte, unsigned long addr)
+{
+	return pte_present(pte) && !is_kernel_addr(addr);
+}
+
 /* Conversion functions: convert a page and protection to a page entry,
  * and a page entry and page directory to the page they refer to.
  *
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index a2ddcbb3fcb9..5de04302c6f4 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -540,6 +540,11 @@ static inline bool pte_access_permitted(pte_t pte, bool write)
 	return arch_pte_access_permitted(pte_val(pte), write, 0);
 }
 
+static inline bool pte_user_accessible_page(pte_t pte, unsigned long addr)
+{
+	return pte_present(pte) && pte_user(pte);
+}
+
 /*
  * Conversion functions: convert a page and protection to a page entry,
  * and a page entry and page directory to the page they refer to.
@@ -1430,5 +1435,17 @@ static inline bool is_pte_rw_upgrade(unsigned long old_val, unsigned long new_va
 	return false;
 }
 
+#define pmd_user_accessible_page pmd_user_accessible_page
+static inline bool pmd_user_accessible_page(pmd_t pmd, unsigned long addr)
+{
+	return pmd_leaf(pmd) && pte_user_accessible_page(pmd_pte(pmd), addr);
+}
+
+#define pud_user_accessible_page pud_user_accessible_page
+static inline bool pud_user_accessible_page(pud_t pud, unsigned long addr)
+{
+	return pud_leaf(pud) && pte_user_accessible_page(pud_pte(pud), addr);
+}
+
 #endif /* __ASSEMBLY__ */
 #endif /* _ASM_POWERPC_BOOK3S_64_PGTABLE_H_ */
diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h
index 7d6b9e5b286e..a8bc4f24beb1 100644
--- a/arch/powerpc/include/asm/nohash/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/pgtable.h
@@ -243,6 +243,11 @@ static inline bool pte_access_permitted(pte_t pte, bool write)
 	return true;
 }
 
+static inline bool pte_user_accessible_page(pte_t pte, unsigned long addr)
+{
+	return pte_present(pte) && !is_kernel_addr(addr);
+}
+
 /* Conversion functions: convert a page and protection to a page entry,
  * and a page entry and page directory to the page they refer to.
  *
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 0f73a9ade0ed..d0938e9c33fb 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -223,6 +223,14 @@ static inline int pud_pfn(pud_t pud)
 }
 #endif
 
+#ifndef pmd_user_accessible_page
+#define pmd_user_accessible_page(pmd, addr)	false
+#endif
+
+#ifndef pud_user_accessible_page
+#define pud_user_accessible_page(pud, addr)	false
+#endif
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_PGTABLE_H */
-- 
2.49.0

[PATCH v15 12/13] powerpc: mm: Use set_pte_at_unchecked() for internal usages

[Andrew Donnellan]

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

In the new set_ptes() API, set_pte_at() (a special case of set_ptes())
is intended to be instrumented by the page table check facility. There
are however several other routines that constitute the API for setting
page table entries, including set_pmd_at() among others. Such routines
are themselves implemented in terms of set_ptes_at().

A future patch providing support for page table checking on powerpc
must take care to avoid duplicate calls to
page_table_check_p{te,md,ud}_set(). Allow for assignment of pte entries
without instrumentation through the set_pte_at_unchecked() routine
introduced in this patch.

Cause API-facing routines that call set_pte_at() to instead call
set_pte_at_unchecked(), which will remain uninstrumented by page
table check. set_ptes() is itself implemented by calls to
__set_pte_at(), so this eliminates redundant code.

[ajd@linux.ibm.com: don't change to unchecked for early boot/kernel mappings]
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
---
v13: don't use the unchecked version for early-boot kernel mappings (Pasha)
---
 arch/powerpc/include/asm/pgtable.h       | 2 ++
 arch/powerpc/mm/book3s64/pgtable.c       | 6 +++---
 arch/powerpc/mm/book3s64/radix_pgtable.c | 6 +++---
 arch/powerpc/mm/pgtable.c                | 8 ++++++++
 4 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index d0938e9c33fb..4fe970992147 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -46,6 +46,8 @@ struct mm_struct;
 void set_ptes(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
 		pte_t pte, unsigned int nr);
 #define set_ptes set_ptes
+void set_pte_at_unchecked(struct mm_struct *mm, unsigned long addr,
+			  pte_t *ptep, pte_t pte);
 #define update_mmu_cache(vma, addr, ptep) \
 	update_mmu_cache_range(NULL, vma, addr, ptep, 1)
 
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index 0db01e10a3f8..1468a815fa5e 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -128,7 +128,7 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 	WARN_ON(!(pmd_leaf(pmd)));
 #endif
 	trace_hugepage_set_pmd(addr, pmd_val(pmd));
-	return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
+	return set_pte_at_unchecked(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
 }
 
 void set_pud_at(struct mm_struct *mm, unsigned long addr,
@@ -145,7 +145,7 @@ void set_pud_at(struct mm_struct *mm, unsigned long addr,
 	WARN_ON(!(pud_leaf(pud)));
 #endif
 	trace_hugepage_set_pud(addr, pud_val(pud));
-	return set_pte_at(mm, addr, pudp_ptep(pudp), pud_pte(pud));
+	return set_pte_at_unchecked(mm, addr, pudp_ptep(pudp), pud_pte(pud));
 }
 
 static void do_serialize(void *arg)
@@ -551,7 +551,7 @@ void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
 	if (radix_enabled())
 		return radix__ptep_modify_prot_commit(vma, addr,
 						      ptep, old_pte, pte);
-	set_pte_at(vma->vm_mm, addr, ptep, pte);
+	set_pte_at_unchecked(vma->vm_mm, addr, ptep, pte);
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index 9f764bc42b8c..2a52089018a5 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -1600,7 +1600,7 @@ void radix__ptep_modify_prot_commit(struct vm_area_struct *vma,
 	    (atomic_read(&mm->context.copros) > 0))
 		radix__flush_tlb_page(vma, addr);
 
-	set_pte_at(mm, addr, ptep, pte);
+	set_pte_at_unchecked(mm, addr, ptep, pte);
 }
 
 int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
@@ -1611,7 +1611,7 @@ int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
 	if (!radix_enabled())
 		return 0;
 
-	set_pte_at(&init_mm, 0 /* radix unused */, ptep, new_pud);
+	set_pte_at_unchecked(&init_mm, 0 /* radix unused */, ptep, new_pud);
 
 	return 1;
 }
@@ -1658,7 +1658,7 @@ int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
 	if (!radix_enabled())
 		return 0;
 
-	set_pte_at(&init_mm, 0 /* radix unused */, ptep, new_pmd);
+	set_pte_at_unchecked(&init_mm, 0 /* radix unused */, ptep, new_pmd);
 
 	return 1;
 }
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index 61df5aed7989..4cc9af7961ca 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -224,6 +224,14 @@ void set_ptes(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
 	}
 }
 
+void set_pte_at_unchecked(struct mm_struct *mm, unsigned long addr,
+			  pte_t *ptep, pte_t pte)
+{
+	VM_WARN_ON(pte_hw_valid(*ptep) && !pte_protnone(*ptep));
+	pte = set_pte_filter(pte, addr);
+	__set_pte_at(mm, addr, ptep, pte, 0);
+}
+
 void unmap_kernel_page(unsigned long va)
 {
 	pmd_t *pmdp = pmd_off_k(va);
-- 
2.49.0

[PATCH v15 13/13] powerpc: mm: Support page table check

[Andrew Donnellan]

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

On creation and clearing of a page table mapping, instrument such calls
by invoking page_table_check_pte_set and page_table_check_pte_clear
respectively. These calls serve as a sanity check against illegal
mappings.

Enable ARCH_SUPPORTS_PAGE_TABLE_CHECK for all platforms.

See also:

riscv support in commit 3fee229a8eb9 ("riscv/mm: enable
ARCH_SUPPORTS_PAGE_TABLE_CHECK")
arm64 in commit 42b2547137f5 ("arm64/mm: enable
ARCH_SUPPORTS_PAGE_TABLE_CHECK")
x86_64 in commit d283d422c6c4 ("x86: mm: add x86_64 support for page table
check")

[ajd@linux.ibm.com: rebase]
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
---
 arch/powerpc/Kconfig                         |  1 +
 arch/powerpc/include/asm/book3s/32/pgtable.h |  7 ++-
 arch/powerpc/include/asm/book3s/64/pgtable.h | 45 +++++++++++++++-----
 arch/powerpc/include/asm/nohash/pgtable.h    |  8 +++-
 arch/powerpc/mm/book3s64/hash_pgtable.c      |  4 ++
 arch/powerpc/mm/book3s64/pgtable.c           | 11 +++--
 arch/powerpc/mm/book3s64/radix_pgtable.c     |  3 ++
 arch/powerpc/mm/pgtable.c                    |  4 ++
 8 files changed, 68 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index c3e0cc83f120..be07827325cc 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -173,6 +173,7 @@ config PPC
 	select ARCH_STACKWALK
 	select ARCH_SUPPORTS_ATOMIC_RMW
 	select ARCH_SUPPORTS_DEBUG_PAGEALLOC	if PPC_BOOK3S || PPC_8xx
+	select ARCH_SUPPORTS_PAGE_TABLE_CHECK
 	select ARCH_USE_BUILTIN_BSWAP
 	select ARCH_USE_CMPXCHG_LOCKREF		if PPC64
 	select ARCH_USE_MEMTEST
diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h
index b225967f85ea..68864a71ca5f 100644
--- a/arch/powerpc/include/asm/book3s/32/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/32/pgtable.h
@@ -202,6 +202,7 @@ void unmap_kernel_page(unsigned long va);
 #ifndef __ASSEMBLY__
 #include <linux/sched.h>
 #include <linux/threads.h>
+#include <linux/page_table_check.h>
 
 /* Bits to mask out from a PGD to get to the PUD page */
 #define PGD_MASKED_BITS		0
@@ -315,7 +316,11 @@ static inline int __ptep_test_and_clear_young(struct mm_struct *mm,
 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 				       pte_t *ptep)
 {
-	return __pte(pte_update(mm, addr, ptep, ~_PAGE_HASHPTE, 0, 0));
+	pte_t old_pte = __pte(pte_update(mm, addr, ptep, ~_PAGE_HASHPTE, 0, 0));
+
+	page_table_check_pte_clear(mm, addr, old_pte);
+
+	return old_pte;
 }
 
 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 5de04302c6f4..b244bb558331 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -145,6 +145,8 @@
 #define PAGE_KERNEL_ROX	__pgprot(_PAGE_BASE | _PAGE_KERNEL_ROX)
 
 #ifndef __ASSEMBLY__
+#include <linux/page_table_check.h>
+
 /*
  * page table defines
  */
@@ -417,8 +419,11 @@ static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
 				       unsigned long addr, pte_t *ptep)
 {
-	unsigned long old = pte_update(mm, addr, ptep, ~0UL, 0, 0);
-	return __pte(old);
+	pte_t old_pte = __pte(pte_update(mm, addr, ptep, ~0UL, 0, 0));
+
+	page_table_check_pte_clear(mm, addr, old_pte);
+
+	return old_pte;
 }
 
 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
@@ -427,11 +432,16 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
 					    pte_t *ptep, int full)
 {
 	if (full && radix_enabled()) {
+		pte_t old_pte;
+
 		/*
 		 * We know that this is a full mm pte clear and
 		 * hence can be sure there is no parallel set_pte.
 		 */
-		return radix__ptep_get_and_clear_full(mm, addr, ptep, full);
+		old_pte = radix__ptep_get_and_clear_full(mm, addr, ptep, full);
+		page_table_check_pte_clear(mm, addr, old_pte);
+
+		return old_pte;
 	}
 	return ptep_get_and_clear(mm, addr, ptep);
 }
@@ -1308,19 +1318,34 @@ extern int pudp_test_and_clear_young(struct vm_area_struct *vma,
 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
 					    unsigned long addr, pmd_t *pmdp)
 {
-	if (radix_enabled())
-		return radix__pmdp_huge_get_and_clear(mm, addr, pmdp);
-	return hash__pmdp_huge_get_and_clear(mm, addr, pmdp);
+	pmd_t old_pmd;
+
+	if (radix_enabled()) {
+		old_pmd = radix__pmdp_huge_get_and_clear(mm, addr, pmdp);
+	} else {
+		old_pmd = hash__pmdp_huge_get_and_clear(mm, addr, pmdp);
+	}
+
+	page_table_check_pmd_clear(mm, addr, old_pmd);
+
+	return old_pmd;
 }
 
 #define __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR
 static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm,
 					    unsigned long addr, pud_t *pudp)
 {
-	if (radix_enabled())
-		return radix__pudp_huge_get_and_clear(mm, addr, pudp);
-	BUG();
-	return *pudp;
+	pud_t old_pud;
+
+	if (radix_enabled()) {
+		old_pud = radix__pudp_huge_get_and_clear(mm, addr, pudp);
+	} else {
+		BUG();
+	}
+
+	page_table_check_pud_clear(mm, addr, old_pud);
+
+	return old_pud;
 }
 
 static inline pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h
index a8bc4f24beb1..3a6630dca615 100644
--- a/arch/powerpc/include/asm/nohash/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/pgtable.h
@@ -29,6 +29,8 @@ static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, p
 
 #ifndef __ASSEMBLY__
 
+#include <linux/page_table_check.h>
+
 extern int icache_44x_need_flush;
 
 #ifndef pte_huge_size
@@ -122,7 +124,11 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 				       pte_t *ptep)
 {
-	return __pte(pte_update(mm, addr, ptep, ~0UL, 0, 0));
+	pte_t old_pte = __pte(pte_update(mm, addr, ptep, ~0UL, 0, 0));
+
+	page_table_check_pte_clear(mm, addr, old_pte);
+
+	return old_pte;
 }
 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
 
diff --git a/arch/powerpc/mm/book3s64/hash_pgtable.c b/arch/powerpc/mm/book3s64/hash_pgtable.c
index 988948d69bc1..c1c25d46dd16 100644
--- a/arch/powerpc/mm/book3s64/hash_pgtable.c
+++ b/arch/powerpc/mm/book3s64/hash_pgtable.c
@@ -8,6 +8,7 @@
 #include <linux/sched.h>
 #include <linux/mm_types.h>
 #include <linux/mm.h>
+#include <linux/page_table_check.h>
 #include <linux/stop_machine.h>
 
 #include <asm/sections.h>
@@ -231,6 +232,9 @@ pmd_t hash__pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long addres
 
 	pmd = *pmdp;
 	pmd_clear(pmdp);
+
+	page_table_check_pmd_clear(vma->vm_mm, address, pmd);
+
 	/*
 	 * Wait for all pending hash_page to finish. This is needed
 	 * in case of subpage collapse. When we collapse normal pages
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index 1468a815fa5e..73924e248087 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -10,6 +10,7 @@
 #include <linux/pkeys.h>
 #include <linux/debugfs.h>
 #include <linux/proc_fs.h>
+#include <linux/page_table_check.h>
 
 #include <asm/pgalloc.h>
 #include <asm/tlb.h>
@@ -128,6 +129,7 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 	WARN_ON(!(pmd_leaf(pmd)));
 #endif
 	trace_hugepage_set_pmd(addr, pmd_val(pmd));
+	page_table_check_pmd_set(mm, addr, pmdp, pmd);
 	return set_pte_at_unchecked(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
 }
 
@@ -145,6 +147,7 @@ void set_pud_at(struct mm_struct *mm, unsigned long addr,
 	WARN_ON(!(pud_leaf(pud)));
 #endif
 	trace_hugepage_set_pud(addr, pud_val(pud));
+	page_table_check_pud_set(mm, addr, pudp, pud);
 	return set_pte_at_unchecked(mm, addr, pudp_ptep(pudp), pud_pte(pud));
 }
 
@@ -180,12 +183,14 @@ void serialize_against_pte_lookup(struct mm_struct *mm)
 pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
 		     pmd_t *pmdp)
 {
-	unsigned long old_pmd;
+	pmd_t old_pmd;
 
 	VM_WARN_ON_ONCE(!pmd_present(*pmdp));
-	old_pmd = pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, _PAGE_INVALID);
+	old_pmd = __pmd(pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, _PAGE_INVALID));
 	flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
-	return __pmd(old_pmd);
+	page_table_check_pmd_clear(vma->vm_mm, address, old_pmd);
+
+	return old_pmd;
 }
 
 pud_t pudp_invalidate(struct vm_area_struct *vma, unsigned long address,
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index 2a52089018a5..b0ad2afc0be0 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -14,6 +14,7 @@
 #include <linux/of.h>
 #include <linux/of_fdt.h>
 #include <linux/mm.h>
+#include <linux/page_table_check.h>
 #include <linux/hugetlb.h>
 #include <linux/string_helpers.h>
 #include <linux/memory.h>
@@ -1468,6 +1469,8 @@ pmd_t radix__pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long addre
 	pmd = *pmdp;
 	pmd_clear(pmdp);
 
+	page_table_check_pmd_clear(vma->vm_mm, address, pmd);
+
 	radix__flush_tlb_collapsed_pmd(vma->vm_mm, address);
 
 	return pmd;
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index 4cc9af7961ca..ed46151ae1d9 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -22,6 +22,7 @@
 #include <linux/mm.h>
 #include <linux/percpu.h>
 #include <linux/hardirq.h>
+#include <linux/page_table_check.h>
 #include <linux/hugetlb.h>
 #include <asm/tlbflush.h>
 #include <asm/tlb.h>
@@ -206,6 +207,9 @@ void set_ptes(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
 	 * and not hw_valid ptes. Hence there is no translation cache flush
 	 * involved that need to be batched.
 	 */
+
+	page_table_check_ptes_set(mm, addr, ptep, pte, nr);
+
 	for (;;) {
 
 		/*
-- 
2.49.0