[External] Re: Question - Livepatch/Kprobe Coexistence on Ftrace-enabled Functions (Ubuntu kernel based on Linux stable 5.15.30)

[Steven Rostedt]

On Mon, 20 Oct 2025 11:53:34 -0700
Song Liu <song at kernel.org> wrote:

> diff --git i/kernel/trace/ftrace.c w/kernel/trace/ftrace.c
> index 42bd2ba68a82..8f320df0ac52 100644
> --- i/kernel/trace/ftrace.c
> +++ w/kernel/trace/ftrace.c
> @@ -6049,6 +6049,9 @@ int register_ftrace_direct(struct ftrace_ops
> *ops, unsigned long addr)
> 
>         err = register_ftrace_function_nolock(ops);
> 
> +       if (err)
> +               remove_direct_functions_hash(hash, addr);
> +
>   out_unlock:
>         mutex_unlock(&direct_mutex);
> 
> 
> Steven,
> 
> Does this change look good to you?

With the small nit that you don't need a space between the err = and the if (err).

But yeah, looks fine to me.

-- Steve