From 4676d57100ff0e944ccd757fd2a849f6e330eed4 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 31 Jan 2023 10:36:30 +0100
Subject: [PATCH] ftrace,kcfi: Define ftrace_stub_graph conditionally

[ Upstream commit dcc0e295396a9ce84dd6a4d1dcc8aed51bc68507 ]

When CONFIG_FUNCTION_GRAPH_TRACER is disabled, __kcfi_typeid_ftrace_stub_graph
is missing, causing a link failure:

 ld.lld: error: undefined symbol: __kcfi_typeid_ftrace_stub_graph
 referenced by arch/x86/kernel/ftrace_64.o:(__cfi_ftrace_stub_graph) in archive vmlinux.a

Mark the reference to it as conditional on the same symbol, as
is done on arm64.

Link: https://lore.kernel.org/linux-trace-kernel/20230131093643.3850272-1-arnd@kernel.org

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Fixes: d57125345156 ("ftrace,kcfi: Separate ftrace_stub() and ftrace_stub_graph()")
See-also: f000be353582 ("arm64: ftrace: Define ftrace_stub_graph only with FUNCTION_GRAPH_TRACER")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/x86/kernel/ftrace_64.S | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S
index 2a4be92fd1444..6233c5b4c10b2 100644
--- a/arch/x86/kernel/ftrace_64.S
+++ b/arch/x86/kernel/ftrace_64.S
@@ -134,9 +134,11 @@ SYM_TYPED_FUNC_START(ftrace_stub)
 	RET
 SYM_FUNC_END(ftrace_stub)
 
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
 SYM_TYPED_FUNC_START(ftrace_stub_graph)
 	RET
 SYM_FUNC_END(ftrace_stub_graph)
+#endif
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 
-- 
2.39.5