Re: [PATCH v2] Re: perf annotate segfaults when source code hasgoto label that looks like hex number

From: Gleb Natapov
Date: Thu Jul 22 2010 - 14:06:05 EST


On Thu, Jul 22, 2010 at 02:05:42PM -0300, Arnaldo Carvalho de Melo wrote:
> Em Thu, Jul 22, 2010 at 01:52:22PM -0300, Arnaldo Carvalho de Melo escreveu:
> > Em Thu, Jul 22, 2010 at 01:47:11PM -0300, Arnaldo Carvalho de Melo escreveu:
> > > Em Thu, Jul 22, 2010 at 07:38:51PM +0300, Gleb Natapov escreveu:
> > > > On Thu, Jul 22, 2010 at 11:33:45AM -0300, Arnaldo Carvalho de Melo wrote:
> > > > > Can you try the attached patch?
> > > > >
> > > > I can, only later. But if I underhand your patch correctly perf will
> > > > still crash if there is a comment after the label on the same line.
> > >
> > > Possibly, will try that now.
> >
> > It could be a comment of play code, like:
> >
> > [root@emilia ~]# cat test.c
> > int main(int argc, char **argv)
> > {
> > int i;
> >
> > while(1) {
> > i++;
> > if (i == 10000000)
> > goto add;
> > }
> > add: return 0;
> > }
> > [root@emilia ~]#
> >
> > back to the drawing board :-\
>
> What about this one?
>
> diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
> index 699cf81..96e9044 100644
> --- a/tools/perf/util/hist.c
> +++ b/tools/perf/util/hist.c
> @@ -976,13 +976,15 @@ static int hist_entry__parse_objdump_line(struct hist_entry *self, FILE *file,
> * Parse hexa addresses followed by ':'
> */
> line_ip = strtoull(tmp, &tmp2, 16);
> - if (*tmp2 != ':' || tmp == tmp2)
> + if (*tmp2 != ':' || tmp == tmp2 || tmp2[1] == '\0')
> line_ip = -1;
> }
>
> if (line_ip != -1) {
> u64 start = map__rip_2objdump(self->ms.map, sym->start);
> offset = line_ip - start;
> + if (offset < 0 || (u64)line_ip > sym->end)
> + offset = -1;
> }
>
This part is good idea anyway. Even if label will be interpreted as ip
perf at least will not crash. It may miss-report something if check will
accidentally succeed though.

> objdump_line = objdump_line__new(offset, line);

--
Gleb.
--
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/