From 2598ac6ec493566105f8a1029aa9de36ba6946ca Mon Sep 17 00:00:00 2001 From: Sami Tolvanen Date: Wed, 9 Nov 2022 19:28:31 +0000 Subject: [PATCH] arm64: ftrace: Define ftrace_stub_graph only with FUNCTION_GRAPH_TRACER The 0-day bot reports that arm64 builds with CONFIG_CFI_CLANG + CONFIG_FTRACE are broken when CONFIG_FUNCTION_GRAPH_TRACER is not enabled: ld.lld: error: undefined symbol: __kcfi_typeid_ftrace_stub_graph >>> referenced by entry-ftrace.S:299 (arch/arm64/kernel/entry-ftrace.S:299) >>> arch/arm64/kernel/entry-ftrace.o:(.text+0x48) in archive vmlinux.a This is caused by ftrace_stub_graph using SYM_TYPE_FUNC_START when the address of the function is not taken in any C translation unit. Fix the build by only defining ftrace_stub_graph when it's actually needed, i.e. with CONFIG_FUNCTION_GRAPH_TRACER. Link: https://lore.kernel.org/lkml/202210251659.tRMs78RH-lkp@intel.com/ Fixes: 883bbbffa5a4 ("ftrace,kcfi: Separate ftrace_stub() and ftrace_stub_graph()") Reported-by: kernel test robot Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook Acked-by: Mark Rutland Reviewed-by: Masami Hiramatsu (Google) Link: https://lore.kernel.org/r/20221109192831.3057131-1-samitolvanen@google.com Signed-off-by: Catalin Marinas --- arch/arm64/kernel/entry-ftrace.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/kernel/entry-ftrace.S b/arch/arm64/kernel/entry-ftrace.S index 795344ab4ec4..322a831f8ede 100644 --- a/arch/arm64/kernel/entry-ftrace.S +++ b/arch/arm64/kernel/entry-ftrace.S @@ -299,11 +299,11 @@ 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) -#ifdef CONFIG_FUNCTION_GRAPH_TRACER /* * void return_to_handler(void) *