On Fri, May 15, 2020 at 4:14 AM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
[...]
> > +static int parse_arg_format(struct tep_print_parse **parse,
> > + struct tep_event *event,
> > + const char *format, struct tep_print_arg
> > **arg) +{
> > + struct tep_print_arg *len_arg = NULL;
> > + char print_format[32];
> > + const char *start = format;
> > + int ret = 0;
> > + int ls = 0;
> > + int res;
> > + int len;
> > +
> > + if (*format != '%')
> > + return ret;
> > + format++;
> > +
> > + /* %% */
> > + if (*format == '%')
> > + return ret;
>
> The above two checks for '%' isn't needed as it is checked by the
> caller. If for some reason that the caller didn't catch it, and we
> return here, it would return zero and the calling loop would never
> proceed. It's not protecting anything, I would just remove these two
> checks.
>
> > + ret++;
> > +
> > + for (; *format; format++) {
> > + switch (*format) {
> > + case '#':
> > + /* FIXME: need to handle properly */
> > + break;
> > + case 'h':
> > + ls--;
> > + break;
> > + case 'l':
> > + ls++;
> > + break;
> > + case 'L':
> > + ls = 2;
> > + break;
> > + case '.':
> > + case 'z':
> > + case 'Z':
> > + case '0' ... '9':
> > + case '-':
> > + break;
> > + case '*':
> > + /* The argument is the length. */
> > + if (!arg) {
> > + do_warning_event(event, "no argument match");
> > + event->flags |= TEP_EVENT_FL_FAILED;
> > + goto out_failed;
> > + }
>
> Since all cases to exit this loop do the same check, I think we can
> move this check before the loop. The old code didn't do this check
> properly for %p, but that was a bug in the old code.
>
We still have to check for a valid argument inside the switch for almost all
exit cases, as the '*' case can consume the argument that would be verified
before the loop. And there is one exit that does not require a valid argument -
the default case. The old code just prints the unknown character, without
consuming an argument.
>
> > + len_arg = *arg;
>
[...]
> -- Steve
Thanks, Steve!
--
Tzvetomir (Ceco) Stoyanov
VMware Open Source Technology Center
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