v4.19.13 snapshot.
diff --git a/arch/arm/include/asm/ftrace.h b/arch/arm/include/asm/ftrace.h
new file mode 100644
index 0000000..9e842ff
--- /dev/null
+++ b/arch/arm/include/asm/ftrace.h
@@ -0,0 +1,82 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_ARM_FTRACE
+#define _ASM_ARM_FTRACE
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+#define ARCH_SUPPORTS_FTRACE_OPS 1
+#endif
+
+#ifdef CONFIG_FUNCTION_TRACER
+#define MCOUNT_ADDR ((unsigned long)(__gnu_mcount_nc))
+#define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */
+
+#ifndef __ASSEMBLY__
+extern void mcount(void);
+extern void __gnu_mcount_nc(void);
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+struct dyn_arch_ftrace {
+#ifdef CONFIG_OLD_MCOUNT
+ bool old_mcount;
+#endif
+};
+
+static inline unsigned long ftrace_call_adjust(unsigned long addr)
+{
+ /* With Thumb-2, the recorded addresses have the lsb set */
+ return addr & ~1;
+}
+
+extern void ftrace_caller_old(void);
+extern void ftrace_call_old(void);
+#endif
+
+#endif
+
+#endif
+
+#ifndef __ASSEMBLY__
+
+#if defined(CONFIG_FRAME_POINTER) && !defined(CONFIG_ARM_UNWIND)
+/*
+ * return_address uses walk_stackframe to do it's work. If both
+ * CONFIG_FRAME_POINTER=y and CONFIG_ARM_UNWIND=y walk_stackframe uses unwind
+ * information. For this to work in the function tracer many functions would
+ * have to be marked with __notrace. So for now just depend on
+ * !CONFIG_ARM_UNWIND.
+ */
+
+void *return_address(unsigned int);
+
+#else
+
+static inline void *return_address(unsigned int level)
+{
+ return NULL;
+}
+
+#endif
+
+#define ftrace_return_address(n) return_address(n)
+
+#define ARCH_HAS_SYSCALL_MATCH_SYM_NAME
+
+static inline bool arch_syscall_match_sym_name(const char *sym,
+ const char *name)
+{
+ if (!strcmp(sym, "sys_mmap2"))
+ sym = "sys_mmap_pgoff";
+ else if (!strcmp(sym, "sys_statfs64_wrapper"))
+ sym = "sys_statfs64";
+ else if (!strcmp(sym, "sys_fstatfs64_wrapper"))
+ sym = "sys_fstatfs64";
+ else if (!strcmp(sym, "sys_arm_fadvise64_64"))
+ sym = "sys_fadvise64_64";
+
+ /* Ignore case since sym may start with "SyS" instead of "sys" */
+ return !strcasecmp(sym, name);
+}
+
+#endif /* ifndef __ASSEMBLY__ */
+
+#endif /* _ASM_ARM_FTRACE */