Messages in this thread | | | Date | Thu, 27 Jul 2023 11:13:11 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH 1/1] perf dlfilter: Initialize addr_location before passing it to thread__find_symbol_fb() |
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Em Tue, Jul 25, 2023 at 02:51:58PM +0300, Adrian Hunter escreveu: > On 25/07/23 00:31, Arnaldo Carvalho de Melo wrote: > > 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.
Or just make al_to_d_al use strdups for the strings it gets from reference counter structs.
That or make the caller of ->resolve_address() provide a initialized addr_location that it then exits.
- Arnaldo
> > I'll do that as well and add the addr_location__exit() then send a V2. > > The data is not valid outside the context of ->filter_event() or > ->filter_event_early(), so the reference counts should not be changed. > That probably needs to be made clearer in the documentation.
> > > > - 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
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