Re: [PATCH] ftrace,kcfi: Separate ftrace_stub() and ftrace_stub_graph()

From: Peter Zijlstra
Date: Tue Oct 18 2022 - 09:19:07 EST


On Tue, Oct 18, 2022 at 02:35:16PM +0200, Peter Zijlstra wrote:
> --- a/include/asm-generic/vmlinux.lds.h
> +++ b/include/asm-generic/vmlinux.lds.h
> @@ -162,6 +162,16 @@
> #define PATCHABLE_DISCARDS *(__patchable_function_entries)
> #endif
>
> +#ifndef ARCH_SUPPORTS_CFI_CLANG

#ifndef CONFIG_ARCH_..

works much better as we found.

> +/*
> + * Simply points to ftrace_stub, but with the proper protocol.
> + * Defined by the linker script in linux/vmlinux.lds.h
> + */
> +#define FTRACE_STUB_HACK ftrace_stub_graph = ftrace_stub;
> +#else
> +#define FTRACE_STUB_HACK
> +#endif

Fixed up version available at:

git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git x86/urgent