Re: [PATCH] ftrace/x86: Add comment on static function tracing

[Steven Rostedt <rostedt@goodmis.org>]

On Tue, 17 Nov 2015 09:43:24 +0900
Namhyung Kim <namhyung@kernel.org> wrote:

> There was a confusion between update_ftrace_function() and static
> function tracing trampoline regarding 3rd parameter (ftrace_ops).
> Add a comment for clarification.
> 
> Suggested-by: Steven Rostedt <rostedt@goodmis.org>

Acked-by: Steven Rostedt <rostedt@goodmis.org>

-- Steve

> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  arch/x86/kernel/mcount_64.S | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/arch/x86/kernel/mcount_64.S b/arch/x86/kernel/mcount_64.S
> index 94ea120fa21f..87e1762e2bca 100644
> --- a/arch/x86/kernel/mcount_64.S
> +++ b/arch/x86/kernel/mcount_64.S
> @@ -278,6 +278,12 @@ GLOBAL(ftrace_stub)
>  	/* save_mcount_regs fills in first two parameters */
>  	save_mcount_regs
>  
> +	/*
> +	 * When DYNAMIC_FTRACE is not defined, ARCH_SUPPORTS_FTRACE_OPS is not
> +	 * set (see include/asm/ftrace.h and include/linux/ftrace.h).  Only the
> +	 * ip and parent ip are used and the list function is called when
> +	 * function tracing is enabled.
> +	 */
>  	call   *ftrace_trace_function
>  
>  	restore_mcount_regs