Re: [PATCH v1 2/3] perf probe: Fix libdw memory leak

[Ian Rogers]

On Wed, Oct 2, 2024 at 10:44 AM Namhyung Kim <namhyung@xxxxxxxxx> wrote:
>
> On Mon, Sep 23, 2024 at 5:37 PM Ian Rogers <irogers@xxxxxxxxxx> wrote:
> >
> > Add missing dwarf_cfi_end to free memory associated with probe_finder
> > cfi_eh or cfi_dbg. This addresses leak sanitizer issues seen in:
> > tools/perf/tests/shell/test_uprobe_from_different_cu.sh
> >
> > Fixes: 270bde1e76f4 ("perf probe: Search both .eh_frame and .debug_frame sections for probe location")
> > Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> > ---
> >  tools/perf/util/probe-finder.c | 5 +++++
> >  1 file changed, 5 insertions(+)
> >
> > diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
> > index 630e16c54ed5..78f34fa0c391 100644
> > --- a/tools/perf/util/probe-finder.c
> > +++ b/tools/perf/util/probe-finder.c
> > @@ -1379,6 +1379,11 @@ int debuginfo__find_trace_events(struct debuginfo *dbg,
> >         if (ret >= 0 && tf.pf.skip_empty_arg)
> >                 ret = fill_empty_trace_arg(pev, tf.tevs, tf.ntevs);
> >
> > +#if _ELFUTILS_PREREQ(0, 142)
> > +       dwarf_cfi_end(tf.pf.cfi_eh);
> > +       dwarf_cfi_end(tf.pf.cfi_dbg);
> > +#endif
>
> This is causing another problem.  Now vfs_getname tests are
> failing because perf probe aborts.

I wasn't able to reproduce but largely as the test skips. The variable
is out of scope after the function so I'm struggling to see what the
issue is.

Thanks,
Ian