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

[Steven Rostedt]

On Wed, 7 Oct 2020 14:08:38 +0100
Colin Ian King <colin.king@xxxxxxxxxxxxx> 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@xxxxxxxxxx>
> 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.

-- 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