From 41918ec82eb6f80c8b401422f27ca76c85aa0cb7 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 25 Jan 2022 15:55:24 +0100 Subject: ARM: ftrace: enable the graph tracer with the EABI unwinder Enable the function graph tracer in combination with the EABI unwinder, so that Thumb2 builds or Clang ARM builds can make use of it. This involves using the unwinder to locate the return address of an instrumented function on the stack, so that it can be overridden and made to refer to the ftrace handling routines that need to be called at function return. Given that for these builds, it is not guaranteed that the value of the link register is stored on the stack, fall back to the stack slot that will be used by the ftrace exit code to restore LR in the instrumented function's execution context. Signed-off-by: Ard Biesheuvel Reviewed-by: Steven Rostedt (Google) --- arch/arm/Kconfig.debug | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm/Kconfig.debug') diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug index 98436702e0c7..b79dc7fa89bf 100644 --- a/arch/arm/Kconfig.debug +++ b/arch/arm/Kconfig.debug @@ -65,7 +65,7 @@ config UNWINDER_FRAME_POINTER config UNWINDER_ARM bool "ARM EABI stack unwinder" - depends on AEABI && !FUNCTION_GRAPH_TRACER + depends on AEABI # https://github.com/ClangBuiltLinux/linux/issues/732 depends on !LD_IS_LLD || LLD_VERSION >= 110000 select ARM_UNWIND -- cgit v1.2.3