Re: [RFC PATCH] scripts/lsan-suppressions: Add a LeakSanitizer suppressions file

[Peter Maydell]

On Mon, 19 Aug 2024 at 23:23, Alex Bennée <alex.bennee@linaro.org> wrote:
>
> Peter Maydell <peter.maydell@linaro.org> writes:
>
> > Add a LeakSanitizer suppressions file that documents and suppresses
> > known false-positive leaks in either QEMU or its dependencies.
> > To use it you'll need to set
> >   LSAN_OPTIONS="suppressions=/path/to/scripts/lsan-suppressions.txt"
> > when running a QEMU built with the leak-sanitizer.
> >
> > The first and currently only entry is for a deliberate leak in glib's
> > g_set_user_dirs() that otherwise causes false positive leak reports
> > in the qga-ssh-test because of its use of G_TEST_OPTION_ISOLATE_DIRS:
>
> Shame we can't share with scripts/oss-fuzz/lsan_supressions.tct:
>
> # The tcmalloc on Fedora37 confuses things
> leak:/lib64/libtcmalloc_minimal.so.4
>
> # libxkbcommon also leaks in qemu-keymap
> leak:/lib64/libxkbcommon.so.0
>
> Or does fuzzing make some things easier to hit?

Ah, I hadn't realised we already had a suppression file.
I think we've just encountered different things.

Plus the fuzzing disables qga-ssh-test in
qga/meson.build rather than suppressing the leak report.
Maybe we could move that to the leak-suppression file,
or maybe it causes some other problem in the fuzzing
context rather than merely a false positive?

(There are also a ton of reported leaks in the GUI libraries
we link against if you run with the GTK GUI, but I haven't
investigated those to see if they're real or something we
should just suppress to reduce the noise.)

thanks
-- PMM