1 files changed, 166 insertions, 0 deletions
diff --git a/include/linux/page_table_check.h b/include/linux/page_table_check.h
new file mode 100644
index 000000000000..01e16c7696ec
--- /dev/null
+++ b/include/linux/page_table_check.h
@@ -0,0 +1,166 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Copyright (c) 2021, Google LLC.
+ * Pasha Tatashin <pasha.tatashin@soleen.com>
+ */
+#ifndef __LINUX_PAGE_TABLE_CHECK_H
+#define __LINUX_PAGE_TABLE_CHECK_H
+
+#ifdef CONFIG_PAGE_TABLE_CHECK
+#include <linux/jump_label.h>
+
+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, 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,
+				  pud_t pud);
+void __page_table_check_pte_set(struct mm_struct *mm, unsigned long addr,
+				pte_t *ptep, pte_t pte);
+void __page_table_check_pmd_set(struct mm_struct *mm, unsigned long addr,
+				pmd_t *pmdp, pmd_t pmd);
+void __page_table_check_pud_set(struct mm_struct *mm, unsigned long addr,
+				pud_t *pudp, pud_t pud);
+void __page_table_check_pte_clear_range(struct mm_struct *mm,
+					unsigned long addr,
+					pmd_t pmd);
+
+static inline void page_table_check_alloc(struct page *page, unsigned int order)
+{
+	if (static_branch_likely(&page_table_check_disabled))
+		return;
+
+	__page_table_check_zero(page, order);
+}
+
+static inline void page_table_check_free(struct page *page, unsigned int order)
+{
+	if (static_branch_likely(&page_table_check_disabled))
+		return;
+
+	__page_table_check_zero(page, order);
+}
+
+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, addr, pte);
+}
+
+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, addr, pmd);
+}
+
+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, addr, pud);
+}
+
+static inline void page_table_check_pte_set(struct mm_struct *mm,
+					    unsigned long addr, pte_t *ptep,
+					    pte_t pte)
+{
+	if (static_branch_likely(&page_table_check_disabled))
+		return;
+
+	__page_table_check_pte_set(mm, addr, ptep, pte);
+}
+
+static inline void page_table_check_pmd_set(struct mm_struct *mm,
+					    unsigned long addr, pmd_t *pmdp,
+					    pmd_t pmd)
+{
+	if (static_branch_likely(&page_table_check_disabled))
+		return;
+
+	__page_table_check_pmd_set(mm, addr, pmdp, pmd);
+}
+
+static inline void page_table_check_pud_set(struct mm_struct *mm,
+					    unsigned long addr, pud_t *pudp,
+					    pud_t pud)
+{
+	if (static_branch_likely(&page_table_check_disabled))
+		return;
+
+	__page_table_check_pud_set(mm, addr, pudp, pud);
+}
+
+static inline void page_table_check_pte_clear_range(struct mm_struct *mm,
+						    unsigned long addr,
+						    pmd_t pmd)
+{
+	if (static_branch_likely(&page_table_check_disabled))
+		return;
+
+	__page_table_check_pte_clear_range(mm, addr, pmd);
+}
+
+#else
+
+static inline void page_table_check_alloc(struct page *page, unsigned int order)
+{
+}
+
+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,
+					      unsigned long addr, pte_t pte)
+{
+}
+
+static inline void page_table_check_pmd_clear(struct mm_struct *mm,
+					      unsigned long addr, pmd_t pmd)
+{
+}
+
+static inline void page_table_check_pud_clear(struct mm_struct *mm,
+					      unsigned long addr, pud_t pud)
+{
+}
+
+static inline void page_table_check_pte_set(struct mm_struct *mm,
+					    unsigned long addr, pte_t *ptep,
+					    pte_t pte)
+{
+}
+
+static inline void page_table_check_pmd_set(struct mm_struct *mm,
+					    unsigned long addr, pmd_t *pmdp,
+					    pmd_t pmd)
+{
+}
+
+static inline void page_table_check_pud_set(struct mm_struct *mm,
+					    unsigned long addr, pud_t *pudp,
+					    pud_t pud)
+{
+}
+
+static inline void page_table_check_pte_clear_range(struct mm_struct *mm,
+						    unsigned long addr,
+						    pmd_t pmd)
+{
+}
+
+#endif /* CONFIG_PAGE_TABLE_CHECK */
+#endif /* __LINUX_PAGE_TABLE_CHECK_H */