Re: [PATCH 3/3] powerpc/mm: Implement CONFIG_DEBUG_RODATA on PPC32

From: Michael Ellerman
Date: Wed Apr 19 2017 - 10:01:50 EST


Christophe Leroy <christophe.leroy@xxxxxx> writes:

> diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c
> index 32509de6ce4c..4af81fb23653 100644
> --- a/arch/powerpc/kernel/ftrace.c
> +++ b/arch/powerpc/kernel/ftrace.c
> @@ -526,7 +526,9 @@ void ftrace_replace_code(int enable)
> */
> void arch_ftrace_update_code(int command)
> {
> + set_kernel_text_rw();
> ftrace_modify_all_code(command);
> + set_kernel_text_ro();
> }

I'm not sure that's the right place for that.

If you look at other arches they hook into ftrace_modify_code(), where
you have the address that's being modified.

cheers