Re: [PATCH] parisc/ftrace: Fix function graph tracing disablement

[Steven Rostedt <rostedt@goodmis.org>]

On Wed,  2 Oct 2024 14:32:04 -0700
Josh Poimboeuf <jpoimboe@kernel.org> wrote:

> Due to an apparent copy-paste bug, the parisc implementation of
> ftrace_disable_ftrace_graph_caller() doesn't actually do anything.  It
> enables the (already-enabled) static key rather than disabling it.
> 
> The result is that after function graph tracing has been "disabled", any
> subsequent (non-graph) function tracing will inadvertently also enable
> the slow fgraph return address hijacking.
> 
> Fixes: 98f2926171ae ("parisc/ftrace: use static key to enable/disable function graph tracer")
> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
> ---
>  arch/parisc/kernel/ftrace.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/parisc/kernel/ftrace.c b/arch/parisc/kernel/ftrace.c
> index c91f9c2e61ed..f8d08eab7db8 100644
> --- a/arch/parisc/kernel/ftrace.c
> +++ b/arch/parisc/kernel/ftrace.c
> @@ -87,7 +87,7 @@ int ftrace_enable_ftrace_graph_caller(void)
>  
>  int ftrace_disable_ftrace_graph_caller(void)
>  {
> -	static_key_enable(&ftrace_graph_enable.key);
> +	static_key_disable(&ftrace_graph_enable.key);
>  	return 0;
>  }
>  #endif

Awfully quite :-/

I wonder if anyone cares about parisc today?

Hmm.

-- Steve