Re: [PATCH] tracing/probe: reverse arguments to list_add

[Steven Rostedt]

On Thu,  7 May 2020 21:30:08 +0200
Julia Lawall <Julia.Lawall@xxxxxxxx> wrote:

> Elsewhere in the file, the function trace_kprobe_has_same_kprobe uses
> a trace_probe_event.probes object as the second argument of
> list_for_each_entry, ie as a list head, while the list_for_each_entry
> iterates over the list fields of the trace_probe structures, making
> them the list elements.  So, exchange the arguments on the list_add
> call to put the list head in the second argument.
> 
> Since both list_head structures were just initialized, this problem
> did not cause any loss of information.
> 
> Fixes: 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe")
> Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxxx>

Masami,

Can you give a Reviewed-by to this?

-- Steve

> 
> ---
>  kernel/trace/trace_probe.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
> index ab8b6436d53f..b8a928e925c7 100644
> --- a/kernel/trace/trace_probe.c
> +++ b/kernel/trace/trace_probe.c
> @@ -1006,7 +1006,7 @@ int trace_probe_init(struct trace_probe *tp, const char *event,
>  	INIT_LIST_HEAD(&tp->event->class.fields);
>  	INIT_LIST_HEAD(&tp->event->probes);
>  	INIT_LIST_HEAD(&tp->list);
> -	list_add(&tp->event->probes, &tp->list);
> +	list_add(&tp->list, &tp->event->probes);
>  
>  	call = trace_probe_event_call(tp);
>  	call->class = &tp->event->class;