Re: [RFC PATCH 4/7] tracing/probe: Check event/group naming rule at parsing

[Masami Hiramatsu]

On Wed, 13 Mar 2019 09:23:55 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> On Wed, 13 Mar 2019 21:28:12 +0900
> Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:
> 
> > Check event and group naming rule at parsing it instead
> > of allocating probes.
> > 
> > Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> > ---
> >  kernel/trace/trace_kprobe.c |    7 +------
> >  kernel/trace/trace_probe.c  |    8 ++++++++
> >  kernel/trace/trace_uprobe.c |    5 +----
> >  3 files changed, 10 insertions(+), 10 deletions(-)
> > 
> > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> > index d47e12596f12..5222fd82e7e4 100644
> > --- a/kernel/trace/trace_kprobe.c
> > +++ b/kernel/trace/trace_kprobe.c
> > @@ -221,7 +221,7 @@ static struct trace_kprobe *alloc_trace_kprobe(const char *group,
> >  
> >  	tk->rp.maxactive = maxactive;
> >  
> > -	if (!event || !is_good_name(event)) {
> > +	if (!event || !group) {
> >  		ret = -EINVAL;
> >  		goto error;
> >  	}
> > @@ -231,11 +231,6 @@ static struct trace_kprobe *alloc_trace_kprobe(const char *group,
> >  	if (!tk->tp.call.name)
> >  		goto error;
> >  
> > -	if (!group || !is_good_name(group)) {
> > -		ret = -EINVAL;
> > -		goto error;
> > -	}
> > -
> >  	tk->tp.class.system = kstrdup(group, GFP_KERNEL);
> >  	if (!tk->tp.class.system)
> >  		goto error;
> > diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
> > index feae03056f0b..1f0cb4030c0b 100644
> > --- a/kernel/trace/trace_probe.c
> > +++ b/kernel/trace/trace_probe.c
> > @@ -172,6 +172,10 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
> >  			return -E2BIG;
> >  		}
> >  		strlcpy(buf, event, slash - event + 1);
> > +		if (!is_good_name(buf)) {
> > +			pr_info("Group name must follow the rule of C identifier\n");
> 
> What do you mean by "C identifier"?

I meant "the naming rules of C language identifiers". It means
that the name has to start with alphabet or "_" and only contain
alphanumeric characters and "_". Does it clear?
I couldn't think of a good word. maybe "naming convention"
does not fit...

Would you have any idea?

Thank you,

> 
> -- Steve
> 
> > +			return -EINVAL;
> > +		}
> >  		*pgroup = buf;
> >  		*pevent = slash + 1;
> >  		event = *pevent;
> > @@ -184,6 +188,10 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
> >  		pr_info("Event name is too long\n");
> >  		return -E2BIG;
> >  	}
> > +	if (!is_good_name(event)) {
> > +		pr_info("Event name must follow the rule of C identifier\n");
> > +		return -EINVAL;
> > +	}
> >  	return 0;
> >  }
> >


-- 
Masami Hiramatsu <mhiramat@xxxxxxxxxx>