Re: [PATCH v2] perf: fix double free at function perf_hpp__reset_output_field

From: Du, Changbin
Date: Sun Apr 09 2017 - 22:16:23 EST


On Sun, Apr 09, 2017 at 07:05:52PM +0200, Jiri Olsa wrote:
> On Wed, Apr 05, 2017 at 10:44:22AM +0800, Du, Changbin wrote:
> > On Tue, Apr 04, 2017 at 12:51:03PM -0300, Arnaldo Carvalho de Melo wrote:
> > > Em Wed, Apr 05, 2017 at 12:34:59AM +0900, Namhyung Kim escreveu:
> > > > Hi Arnaldo,
> > > >
> > > > On Wed, Apr 5, 2017 at 12:19 AM, Arnaldo Carvalho de Melo
> > > > <acme@xxxxxxxxxx> wrote:
> > > > > Em Mon, Mar 27, 2017 at 02:22:55PM +0800, changbin.du@xxxxxxxxx escreveu:
> > > > >> From: Changbin Du <changbin.du@xxxxxxxxx>
> > > > >>
> > > > >> Some perf_hpp_fmt both registered at field and sort list. For such
> > > > >> instance, we only can free it when removed from the both lists. This
> > > > >> function currently only used by self-test code, but still should fix
> > > > >> it.
> > > > >
> > > > > Looks sane, applying,
> > > > >
> > > > > Jiri, Namhyung, please holler (or ack) if needed,
> > > >
> > > > Did you actually see the double free problem? AFAICS the old code
> > >
> > > I assumed that he had seen it, in some self-test code, Changbin, can you
> > > please show command output or further describe when this patch would be
> > > necessary?
> > >
> > Arnaldo, I did observe this issue but not in self-test code. The self-test code
> > uses that function but does not have a case that a fmt linked to two both list.
> > I found this issue when I try to add 'dynamic sort' feature to perf, which
> > I use this function to reset out fields.
>
> could you post it with the rest of your patches? might be easier to review
>
jirka, I am sorry that the 'dynamic sort' is only half done. Now I am
very busy with work at hand. I will send the rest of patches when I
finish them. Could we check out this fix first?

> thanks,
> jirka

--
Thanks,
Changbin Du

Attachment: signature.asc
Description: PGP signature