From 9ac687a280aad334d89eb5af80f3465d3df3e601 Mon Sep 17 00:00:00 2001
From: Heiko Carstens <hca@linux.ibm.com>
Date: Mon, 27 Jul 2026 16:05:10 +0200
Subject: [PATCH] s390: Add ftrace_stub_graph

This is the s390 variant of commit f3a0c23f2539 ("riscv: Add
ftrace_stub_graph"):

"Commit 883bbbffa5a4 ("ftrace,kcfi: Separate ftrace_stub() and
ftrace_stub_graph()") added a separate ftrace_stub_graph function for
CFI_CLANG. Add the stub to fix FUNCTION_GRAPH_TRACER compatibility
with CFI."

Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
---
 arch/s390/kernel/mcount.S | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/s390/kernel/mcount.S b/arch/s390/kernel/mcount.S
index 1fec370fecf4..6bc44c767642 100644
--- a/arch/s390/kernel/mcount.S
+++ b/arch/s390/kernel/mcount.S
@@ -4,6 +4,7 @@
  *
  */
 
+#include <linux/cfi_types.h>
 #include <linux/linkage.h>
 #include <asm/asm-offsets.h>
 #include <asm/ftrace.h>
@@ -34,10 +35,16 @@
 
 	.section .kprobes.text, "ax"
 
-SYM_FUNC_START(ftrace_stub)
+SYM_TYPED_FUNC_START(ftrace_stub)
 	BR_EX	%r14
 SYM_FUNC_END(ftrace_stub)
 
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+SYM_TYPED_FUNC_START(ftrace_stub_graph)
+	BR_EX	%r14
+SYM_FUNC_END(ftrace_stub_graph)
+#endif
+
 SYM_CODE_START(ftrace_stub_direct_tramp)
 	lgr	%r1, %r0
 	BR_EX	%r1