Re: [PATCH v4 1/3] tracing: eprobe: remove duplicate is_good_name() operation

[Linyu Yuan]

hi Tom,

On 6/14/2022 5:01 AM, Tom Zanussi wrote:
> Hi Linhu,
>
> On Thu, 2022-06-02 at 20:10 +0800, Linyu Yuan wrote:
> > traceprobe_parse_event_name() already validate group and event name,
> > there is no need to call is_good_name() after it.
> >
> > Signed-off-by: Linyu Yuan <quic_linyyuan@xxxxxxxxxxx>
> > ---
> > v2: drop v1 change as it is NACK.
> >      add it to remove duplicate is_good_name().
> > v3: move it as first patch.
> > v4: no change
> >
> >   kernel/trace/trace_eprobe.c | 4 ----
> >   1 file changed, 4 deletions(-)
> >
> > diff --git a/kernel/trace/trace_eprobe.c
> > b/kernel/trace/trace_eprobe.c
> > index 7d44785..17d64e3 100644
> > --- a/kernel/trace/trace_eprobe.c
> > +++ b/kernel/trace/trace_eprobe.c
> > @@ -878,16 +878,12 @@ static int __trace_eprobe_create(int argc,
> > const char *argv[])
> >                  sanitize_event_name(buf1);
> >                  event = buf1;
> >          }
> > -       if (!is_good_name(event) || !is_good_name(group))
> > -               goto parse_error;
> traceprobe_parse_event_name() is only called if (event).  In the
> !event case, wouldn't the is_good_name() checks still be needed (since
> in that case buf1 is assigned to event)?

when user input no  event name, it will generate event name from second  
SYSTEM.EVENT,

and it will validate with following traceprobe_parse_event_name().


(

if you agree, i will send a new version to update a minor issue in 
second patch,


        sys_event = argv[1];
-       ret = traceprobe_parse_event_name(&sys_event, &sys_name, buf2,
-                                         sys_event - argv[1]);
-       if (ret || !sys_name)
+       ret = traceprobe_parse_event_name(&sys_event, &sys_name, buf2, 0);
+       if (!sys_event || !sys_name)
                goto parse_error;

)

> >   
> >          sys_event = argv[1];
> >          ret = traceprobe_parse_event_name(&sys_event, &sys_name,
> > buf2,
> >                                            sys_event - argv[1]);
> >          if (ret || !sys_name)
> >                  goto parse_error;
> > -       if (!is_good_name(sys_event) || !is_good_name(sys_name))
> > -               goto parse_error;
> I agree this one isn't needed.
>
> Thanks,
>
> Tom
>
> >   
> >          mutex_lock(&event_mutex);
> >          event_call = find_and_get_event(sys_name, sys_event);