Re: [PATCH 1/1] perf dlfilter: Initialize addr_location before passing it to thread__find_symbol_fb()

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Mon, Jul 24, 2023 at 02:16:05PM -0700, Ian Rogers escreveu:
> On Mon, Jul 24, 2023 at 2:09 PM Arnaldo Carvalho de Melo
> <acme@kernel.org> wrote:
> >
> > As thread__find_symbol_fb() will end up calling thread__find_map() and
> > it in turn will call these on uninitialized memory:
> >
> >         maps__zput(al->maps);
> >         map__zput(al->map);
> >         thread__zput(al->thread);
> 
> Normally there would be a addr_location__exit. It looks here like most
> values are copied in al_to_d_al, which copies reference counted values
> without doing appropriate gets. Perhaps add the gets in al_to_d_al and
> add the exit to make it clear there can't be addr_location related
> leaks here.

I'll do that as well and add the addr_location__exit() then send a V2.

- Arnaldo
 
> Thanks,
> Ian
> 
> > Fixes: 0dd5041c9a0eaf8c ("perf addr_location: Add init/exit/copy functions")
> > Cc: Adrian Hunter <adrian.hunter@intel.com>
> > Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> > Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
> > Cc: Disha Goel <disgoel@linux.vnet.ibm.com>
> > Cc: Ian Rogers <irogers@google.com>
> > Cc: Jiri Olsa <jolsa@kernel.org>
> > Cc: Kajol Jain <kjain@linux.ibm.com>
> > Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
> > Cc: Namhyung Kim <namhyung@kernel.org>
> > Link: https://lore.kernel.org/lkml/
> > Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> > ---
> >  tools/perf/util/dlfilter.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/tools/perf/util/dlfilter.c b/tools/perf/util/dlfilter.c
> > index 46f74b2344dbb34c..798a53d7e6c9dfc5 100644
> > --- a/tools/perf/util/dlfilter.c
> > +++ b/tools/perf/util/dlfilter.c
> > @@ -166,6 +166,7 @@ static __s32 dlfilter__resolve_address(void *ctx, __u64 address, struct perf_dlf
> >         if (!thread)
> >                 return -1;
> >
> > +       addr_location__init(&al);
> >         thread__find_symbol_fb(thread, d->sample->cpumode, address, &al);
> >
> >         al_to_d_al(&al, &d_al);
> > --
> > 2.37.1
> >

-- 

- Arnaldo