Re: [PATCH v2 2/4] fprobe: make fprobe_kprobe_handler recursion free

[Ze Gao]

Thanks for pointing this out,  I'll get it all fixed ASAP.

Regards,
Ze

On Tue, May 16, 2023 at 5:16 PM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> On Tue, May 16, 2023 at 03:18:28PM +0800, Ze Gao wrote:
>
> > +static void fprobe_handler(unsigned long ip, unsigned long parent_ip,
> > +             struct ftrace_ops *ops, struct ftrace_regs *fregs)
> > +{
> > +     struct fprobe *fp;
> > +     int bit;
> > +
> > +     fp = container_of(ops, struct fprobe, ops);
> > +     if (fprobe_disabled(fp))
> > +             return;
> > +
> > +     /* recursion detection has to go before any traceable function and
> > +      * all functions before this point should be marked as notrace
> > +      */
> > +     bit = ftrace_test_recursion_trylock(ip, parent_ip);
> > +     if (bit < 0) {
> > +             fp->nmissed++;
> > +             return;
> > +     }
> > +     __fprobe_handler(ip, parent_ip, ops, fregs);
> >       ftrace_test_recursion_unlock(bit);
> > +
> >  }
> >  NOKPROBE_SYMBOL(fprobe_handler);
> >
> >  static void fprobe_kprobe_handler(unsigned long ip, unsigned long parent_ip,
> >                                 struct ftrace_ops *ops, struct ftrace_regs *fregs)
> >  {
> > -     struct fprobe *fp = container_of(ops, struct fprobe, ops);
> > +     struct fprobe *fp;
> > +     int bit;
> > +
> > +     fp = container_of(ops, struct fprobe, ops);
> > +     if (fprobe_disabled(fp))
> > +             return;
> > +
> > +     /* recursion detection has to go before any traceable function and
> > +      * all functions called before this point should be marked as notrace
> > +      */
> > +     bit = ftrace_test_recursion_trylock(ip, parent_ip);
> > +     if (bit < 0) {
> > +             fp->nmissed++;
> > +             return;
> > +     }
>
> Please don't use this comment style; multi line comments go like:
>
>         /*
>          * Multi line comment ...
>          *                    ... is symmetric.
>          */
>
> Same for your next patch.