[PATCH 5.10 134/148] x86/ftrace: Add UNWIND_HINT_FUNC annotation for ftrace_stub

[Greg Kroah-Hartman]

From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>

commit 18660698a3d30868524cefb60dcd4e0e297f71bb upstream.

Prevent an unreachable objtool warning after the sibling call detection
gets improved.  ftrace_stub() is basically a function, annotate it as
such.

Acked-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Link: https://lore.kernel.org/r/6845e1b2fb0723a95740c6674e548ba38c5ea489.1611263461.git.jpoimboe@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 arch/x86/kernel/ftrace_64.S |    1 +
 1 file changed, 1 insertion(+)

--- a/arch/x86/kernel/ftrace_64.S
+++ b/arch/x86/kernel/ftrace_64.S
@@ -173,6 +173,7 @@ SYM_INNER_LABEL(ftrace_graph_call, SYM_L
  * It is also used to copy the RET for trampolines.
  */
 SYM_INNER_LABEL_ALIGN(ftrace_stub, SYM_L_WEAK)
+	UNWIND_HINT_FUNC
 	RET
 SYM_FUNC_END(ftrace_epilogue)