Re: tracing: Add support for dynamic strings to synthetic events

[Tom Zanussi <zanussi@kernel.org>]

On Wed, 2020-10-07 at 09:30 -0400, Steven Rostedt wrote:
> On Wed, 7 Oct 2020 14:08:38 +0100
> Colin Ian King <colin.king@canonical.com> wrote:
> 
> > Hi,
> > 
> > Static analysis with Coverity has detected a duplicated condition
> > in an
> > if statement in the following commit in source
> > kernel/trace/trace_events_synth.c
> > 
> > commit bd82631d7ccdc894af2738e47abcba2cb6e7dea9
> > Author: Tom Zanussi <zanussi@kernel.org>
> > Date:   Sun Oct 4 17:14:06 2020 -0500
> > 
> >     tracing: Add support for dynamic strings to synthetic events
> > 
> > Analysis is as follows:
> > 
> > 493        for (i = 0; i < event->n_fields; i++) {
> > 
> > Same on both sides (CONSTANT_EXPRESSION_RESULT)
> > pointless_expression: The expression event->fields[i]->is_dynamic
> > &&
> > event->fields[i]->is_dynamic does not accomplish anything because
> > it
> > evaluates to either of its identical operands, event->fields[i]-
> > >is_dynamic.
> > 
> >    Did you intend the operands to be different?
> > 
> > 494                if (event->fields[i]->is_dynamic &&
> > 495                    event->fields[i]->is_dynamic)
> 
> Bah, I believe that was suppose to be:
> 
> 		if (event->fields[i]->is_string &&
> 		    event->fields[i]->is_dynamic)
> 
> I'll go and fix that.
> 

Yep, thanks for fixing that.

Acked-by: Tom Zanussi <zanussi@kernel.org>


Tom

> -- Steve
> 
> > 496                        pos += snprintf(buf + pos, LEN_OR_ZERO,
> > 497                                ", __get_str(%s)",
> > event->fields[i]->name);
> > 498                else
> > 499                        pos += snprintf(buf + pos, LEN_OR_ZERO,
> > 500                                        ", REC->%s",
> > event->fields[i]->name);
> > 501        }
> > 
> > Colin
> 
>