--- zzzz-none-000/linux-3.10.107/arch/s390/include/asm/ftrace.h	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/arch/s390/include/asm/ftrace.h	2021-02-04 17:41:59.000000000 +0000
@@ -1,26 +1,84 @@
 #ifndef _ASM_S390_FTRACE_H
 #define _ASM_S390_FTRACE_H
 
+#define ARCH_SUPPORTS_FTRACE_OPS 1
+
+#ifdef CC_USING_HOTPATCH
+#define MCOUNT_INSN_SIZE	6
+#else
+#define MCOUNT_INSN_SIZE	24
+#define MCOUNT_RETURN_FIXUP	18
+#endif
+
 #ifndef __ASSEMBLY__
 
-extern void _mcount(void);
+#define ftrace_return_address(n) __builtin_return_address(n)
+
+void _mcount(void);
+void ftrace_caller(void);
+
+extern char ftrace_graph_caller_end;
+extern unsigned long ftrace_plt;
 
 struct dyn_arch_ftrace { };
 
-#define MCOUNT_ADDR ((long)_mcount)
+#define MCOUNT_ADDR ((unsigned long)_mcount)
+#define FTRACE_ADDR ((unsigned long)ftrace_caller)
 
+#define KPROBE_ON_FTRACE_NOP	0
+#define KPROBE_ON_FTRACE_CALL	1
 
 static inline unsigned long ftrace_call_adjust(unsigned long addr)
 {
 	return addr;
 }
 
-#endif /* __ASSEMBLY__ */
+struct ftrace_insn {
+	u16 opc;
+	s32 disp;
+} __packed;
+
+static inline void ftrace_generate_nop_insn(struct ftrace_insn *insn)
+{
+#ifdef CONFIG_FUNCTION_TRACER
+#ifdef CC_USING_HOTPATCH
+	/* brcl 0,0 */
+	insn->opc = 0xc004;
+	insn->disp = 0;
+#else
+	/* jg .+24 */
+	insn->opc = 0xc0f4;
+	insn->disp = MCOUNT_INSN_SIZE / 2;
+#endif
+#endif
+}
 
-#ifdef CONFIG_64BIT
-#define MCOUNT_INSN_SIZE  12
+static inline int is_ftrace_nop(struct ftrace_insn *insn)
+{
+#ifdef CONFIG_FUNCTION_TRACER
+#ifdef CC_USING_HOTPATCH
+	if (insn->disp == 0)
+		return 1;
 #else
-#define MCOUNT_INSN_SIZE  22
+	if (insn->disp == MCOUNT_INSN_SIZE / 2)
+		return 1;
 #endif
+#endif
+	return 0;
+}
 
+static inline void ftrace_generate_call_insn(struct ftrace_insn *insn,
+					     unsigned long ip)
+{
+#ifdef CONFIG_FUNCTION_TRACER
+	unsigned long target;
+
+	/* brasl r0,ftrace_caller */
+	target = is_module_addr((void *) ip) ? ftrace_plt : FTRACE_ADDR;
+	insn->opc = 0xc005;
+	insn->disp = (target - ip) / 2;
+#endif
+}
+
+#endif /* __ASSEMBLY__ */
 #endif /* _ASM_S390_FTRACE_H */