v4.19.13 snapshot.
diff --git a/include/asm-generic/mm_hooks.h b/include/asm-generic/mm_hooks.h
new file mode 100644
index 0000000..8ac4e68
--- /dev/null
+++ b/include/asm-generic/mm_hooks.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Define generic no-op hooks for arch_dup_mmap, arch_exit_mmap
+ * and arch_unmap to be included in asm-FOO/mmu_context.h for any
+ * arch FOO which doesn't need to hook these.
+ */
+#ifndef _ASM_GENERIC_MM_HOOKS_H
+#define _ASM_GENERIC_MM_HOOKS_H
+
+static inline int arch_dup_mmap(struct mm_struct *oldmm,
+ struct mm_struct *mm)
+{
+ return 0;
+}
+
+static inline void arch_exit_mmap(struct mm_struct *mm)
+{
+}
+
+static inline void arch_unmap(struct mm_struct *mm,
+ struct vm_area_struct *vma,
+ unsigned long start, unsigned long end)
+{
+}
+
+static inline void arch_bprm_mm_init(struct mm_struct *mm,
+ struct vm_area_struct *vma)
+{
+}
+
+static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
+ bool write, bool execute, bool foreign)
+{
+ /* by default, allow everything */
+ return true;
+}
+#endif /* _ASM_GENERIC_MM_HOOKS_H */