On Mon, 23 Sep 2019 16:12:53 +0530
Srikar Dronamraju <[email protected]> wrote:
> Hey Masami, Steven
>
> >
> > +static bool trace_kprobe_has_same_kprobe(struct trace_kprobe *orig,
> > + struct trace_kprobe *comp)
> > +{
> > + struct trace_probe_event *tpe = orig->tp.event;
> > + struct trace_probe *pos;
> > + int i;
> > +
> > + list_for_each_entry(pos, &tpe->probes, list) {
> > + orig = container_of(pos, struct trace_kprobe, tp);
> > + if (strcmp(trace_kprobe_symbol(orig),
> > + trace_kprobe_symbol(comp)) ||
> > + trace_kprobe_offset(orig) != trace_kprobe_offset(comp))
> > + continue;
> > +
> > + /*
> > + * trace_probe_compare_arg_type() ensured that nr_args and
> > + * each argument name and type are same. Let's compare comm.
> > + */
> > + for (i = 0; i < orig->tp.nr_args; i++) {
> > + if (strcmp(orig->tp.args[i].comm,
> > + comp->tp.args[i].comm))
> > + continue;
>
> In a nested loop, *continue* is going to continue iterating through the
> inner loop. In which case, continue is doing nothing here. I thought we
> should have used a goto instead. No? To me, continue as a last statement of
> a for loop always looks weird.
Oops, thanks for pointing it out!
>
> > + }
> > +
> > + return true;
> > + }
>
> I think we need something like this:
>
> list_for_each_entry(pos, &tpe->probes, list) {
> orig = container_of(pos, struct trace_kprobe, tp);
> if (strcmp(trace_kprobe_symbol(orig),
> trace_kprobe_symbol(comp)) ||
> trace_kprobe_offset(orig) != trace_kprobe_offset(comp))
> continue;
>
> /*
> * trace_probe_compare_arg_type() ensured that nr_args and
> * each argument name and type are same. Let's compare comm.
> */
> for (i = 0; i < orig->tp.nr_args; i++) {
> if (strcmp(orig->tp.args[i].comm,
> comp->tp.args[i].comm))
> goto outer_loop;
>
> }
>
> return true;
> outer_loop:
> }
Correct, that's what I intended.
Could you make a fix patch on top of it? (or do I?)
Thank you,
>
>
> > +
> > + return false;
> > +}
> > +
> >
>
> ......
>
> > +static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig,
> > + struct trace_uprobe *comp)
> > +{
> > + struct trace_probe_event *tpe = orig->tp.event;
> > + struct trace_probe *pos;
> > + struct inode *comp_inode = d_real_inode(comp->path.dentry);
> > + int i;
> > +
> > + list_for_each_entry(pos, &tpe->probes, list) {
> > + orig = container_of(pos, struct trace_uprobe, tp);
> > + if (comp_inode != d_real_inode(orig->path.dentry) ||
> > + comp->offset != orig->offset)
> > + continue;
> > +
> > + /*
> > + * trace_probe_compare_arg_type() ensured that nr_args and
> > + * each argument name and type are same. Let's compare comm.
> > + */
> > + for (i = 0; i < orig->tp.nr_args; i++) {
> > + if (strcmp(orig->tp.args[i].comm,
> > + comp->tp.args[i].comm))
> > + continue;
>
> Same as above.
>
> > + }
> > +
> > + return true;
> > + }
> > +
> > + return false;
> > +}
> > +
>
> --
> Thanks and Regards
> Srikar Dronamraju
>
--
Masami Hiramatsu <[email protected]>
