Merge branch 'page-table-check-support' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux into features

Add s390 support for CONFIG_PAGE_TABLE_CHECK.

* 'page-table-check-support' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390: Enable page table check for debug_defconfig
  s390/pgtable: Add s390 support for page table check
  s390/pgtable: Use set_pmd_bit() to invalidate PMD entry
  mm/page_table_check: Pass mm_struct to pxx_user_accessible_page()

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

1 files changed, 53 insertions, 7 deletions

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 1c3c3be93be9..67f5df20a57e 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -16,8 +16,10 @@
 #include <linux/mm_types.h>
 #include <linux/cpufeature.h>
 #include <linux/page-flags.h>
+#include <linux/page_table_check.h>
 #include <linux/radix-tree.h>
 #include <linux/atomic.h>
+#include <linux/mmap_lock.h>
 #include <asm/ctlreg.h>
 #include <asm/bug.h>
 #include <asm/page.h>
@@ -1190,6 +1192,7 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
 	/* At this point the reference through the mapping is still present */
 	if (mm_is_protected(mm) && pte_present(res))
 		WARN_ON_ONCE(uv_convert_from_secure_pte(res));
+	page_table_check_pte_clear(mm, addr, res);
 	return res;
 }
 
@@ -1208,6 +1211,7 @@ static inline pte_t ptep_clear_flush(struct vm_area_struct *vma,
 	/* At this point the reference through the mapping is still present */
 	if (mm_is_protected(vma->vm_mm) && pte_present(res))
 		WARN_ON_ONCE(uv_convert_from_secure_pte(res));
+	page_table_check_pte_clear(vma->vm_mm, addr, res);
 	return res;
 }
 
@@ -1231,6 +1235,9 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
 	} else {
 		res = ptep_xchg_lazy(mm, addr, ptep, __pte(_PAGE_INVALID));
 	}
+
+	page_table_check_pte_clear(mm, addr, res);
+
 	/* Nothing to do */
 	if (!mm_is_protected(mm) || !pte_present(res))
 		return res;
@@ -1327,6 +1334,7 @@ static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
 {
 	if (pte_present(entry))
 		entry = clear_pte_bit(entry, __pgprot(_PAGE_UNUSED));
+	page_table_check_ptes_set(mm, addr, ptep, entry, nr);
 	for (;;) {
 		set_pte(ptep, entry);
 		if (--nr == 0)
@@ -1703,6 +1711,7 @@ static inline int pmdp_clear_flush_young(struct vm_area_struct *vma,
 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 			      pmd_t *pmdp, pmd_t entry)
 {
+	page_table_check_pmd_set(mm, addr, pmdp, entry);
 	set_pmd(pmdp, entry);
 }
 
@@ -1717,7 +1726,11 @@ static inline pmd_t pmd_mkhuge(pmd_t pmd)
 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
 					    unsigned long addr, pmd_t *pmdp)
 {
-	return pmdp_xchg_direct(mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
+	pmd_t pmd;
+
+	pmd = pmdp_xchg_direct(mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
+	page_table_check_pmd_clear(mm, addr, pmd);
+	return pmd;
 }
 
 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR_FULL
@@ -1725,12 +1738,17 @@ static inline pmd_t pmdp_huge_get_and_clear_full(struct vm_area_struct *vma,
 						 unsigned long addr,
 						 pmd_t *pmdp, int full)
 {
+	pmd_t pmd;
+
 	if (full) {
-		pmd_t pmd = *pmdp;
+		pmd = *pmdp;
 		set_pmd(pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
+		page_table_check_pmd_clear(vma->vm_mm, addr, pmd);
 		return pmd;
 	}
-	return pmdp_xchg_lazy(vma->vm_mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
+	pmd = pmdp_xchg_lazy(vma->vm_mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
+	page_table_check_pmd_clear(vma->vm_mm, addr, pmd);
+	return pmd;
 }
 
 #define __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSH
@@ -1744,11 +1762,16 @@ static inline pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma,
 static inline pmd_t pmdp_invalidate(struct vm_area_struct *vma,
 				   unsigned long addr, pmd_t *pmdp)
 {
-	pmd_t pmd;
+	pmd_t pmd = *pmdp;
 
-	VM_WARN_ON_ONCE(!pmd_present(*pmdp));
-	pmd = __pmd(pmd_val(*pmdp) | _SEGMENT_ENTRY_INVALID);
-	return pmdp_xchg_direct(vma->vm_mm, addr, pmdp, pmd);
+	VM_WARN_ON_ONCE(!pmd_present(pmd));
+	pmd = set_pmd_bit(pmd, __pgprot(_SEGMENT_ENTRY_INVALID));
+#ifdef CONFIG_PAGE_TABLE_CHECK
+	pmd = clear_pmd_bit(pmd, __pgprot(_SEGMENT_ENTRY_READ));
+#endif
+	page_table_check_pmd_set(vma->vm_mm, addr, pmdp, pmd);
+	pmd = pmdp_xchg_direct(vma->vm_mm, addr, pmdp, pmd);
+	return pmd;
 }
 
 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
@@ -1783,6 +1806,29 @@ static inline int has_transparent_hugepage(void)
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
+#ifdef CONFIG_PAGE_TABLE_CHECK
+static inline bool pte_user_accessible_page(struct mm_struct *mm, unsigned long addr, pte_t pte)
+{
+	VM_BUG_ON(mm == &init_mm);
+
+	return pte_present(pte);
+}
+
+static inline bool pmd_user_accessible_page(struct mm_struct *mm, unsigned long addr, pmd_t pmd)
+{
+	VM_BUG_ON(mm == &init_mm);
+
+	return pmd_leaf(pmd) && (pmd_val(pmd) & _SEGMENT_ENTRY_READ);
+}
+
+static inline bool pud_user_accessible_page(struct mm_struct *mm, unsigned long addr, pud_t pud)
+{
+	VM_BUG_ON(mm == &init_mm);
+
+	return pud_leaf(pud);
+}
+#endif
+
 /*
  * 64 bit swap entry format:
  * A page-table entry has some bits we have to treat in a special way.