Re: [PATCH] perf target: Ignore return value of strerror_r() explicitly

[Namhyung Kim]

2012-07-03 12:34 AM, Arnaldo Carvalho de Melo wrote:
> Em Mon, Jul 02, 2012 at 03:20:14PM +0900, Namhyung Kim escreveu:
> > Since glibc 2.16 added the warn_unused_result (wur) attribute
> > to the function, we should check the return value or ignore it
> > explicitly.
> >
> > Reported-by: Markus Trippelsdorf <markus@xxxxxxxxxxxxxxx>
> > Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
>
> > +++ b/tools/perf/util/target.c
> > @@ -111,7 +111,8 @@ int perf_target__strerror(struct perf_target *target, int errnum,
> >   	const char *msg;
> >
> >   	if (errnum >= 0) {
> > -		strerror_r(errnum, buf, buflen);
> > +		/* make glibc (>= 2.16) happy */
> > +		(void)strerror_r(errnum, buf, buflen);
>
> Is this really the best way to handle this?
>
> What if some perf tool is buggy and passes an invalid errnum?  Shouldn't
> we catch that?

$ man strerror_r
...
RETURN VALUE
       The  strerror()  and  the  GNU-specific strerror_r() functions
       return the appropriate error description string, or an
       "Unknown error nnn" message if the error number is unknown.

Isn't it sufficient? Or we can reset the @buf at the beginning for the case of 
a invalid negative @errnum.

Thanks,
Namhyung

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/