From: Andrea Righi <andrea.righi@canonical.com>
To: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>,
Alexander Potapenko <glider@google.com>,
kasan-dev@googlegroups.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: BUG: soft lockup in __kmalloc_node() with KFENCE enabled
Date: Wed, 20 Oct 2021 08:11:21 +0200 [thread overview]
Message-ID: <YW+zCbaf1Xb8lBMo@arighi-desktop> (raw)
In-Reply-To: <CANpmjNMXNZX5QyLhXtT87ycnAhEe1upU_cL9D3+NOGKEn-gtCw@mail.gmail.com>
On Wed, Oct 20, 2021 at 08:00:00AM +0200, Marco Elver wrote:
> On Mon, 11 Oct 2021 at 16:42, Andrea Righi <andrea.righi@canonical.com> wrote:
> > On Mon, Oct 11, 2021 at 12:03:52PM +0200, Marco Elver wrote:
> > > On Mon, 11 Oct 2021 at 11:53, Andrea Righi <andrea.righi@canonical.com> wrote:
> > > > On Mon, Oct 11, 2021 at 11:23:32AM +0200, Andrea Righi wrote:
> > > > ...
> > > > > > You seem to use the default 20s stall timeout. FWIW syzbot uses 160
> > > > > > secs timeout for TCG emulation to avoid false positive warnings:
> > > > > > https://github.com/google/syzkaller/blob/838e7e2cd9228583ca33c49a39aea4d863d3e36d/dashboard/config/linux/upstream-arm64-kasan.config#L509
> > > > > > There are a number of other timeouts raised as well, some as high as
> > > > > > 420 seconds.
> > > > >
> > > > > I see, I'll try with these settings and see if I can still hit the soft
> > > > > lockup messages.
> > > >
> > > > Still getting soft lockup messages even with the new timeout settings:
> > > >
> > > > [ 462.663766] watchdog: BUG: soft lockup - CPU#2 stuck for 430s! [systemd-udevd:168]
> > > > [ 462.755758] watchdog: BUG: soft lockup - CPU#3 stuck for 430s! [systemd-udevd:171]
> > > > [ 924.663765] watchdog: BUG: soft lockup - CPU#2 stuck for 861s! [systemd-udevd:168]
> > > > [ 924.755767] watchdog: BUG: soft lockup - CPU#3 stuck for 861s! [systemd-udevd:171]
> > >
> > > The lockups are expected if you're hitting the TCG bug I linked. Try
> > > to pass '-enable-kvm' to the inner qemu instance (my bad if you
> > > already have), assuming that's somehow easy to do.
> >
> > If I add '-enable-kvm' I can triggering other random panics (almost
> > immediately), like this one for example:
>
> Just FYI: https://lkml.kernel.org/r/20211019102524.2807208-2-elver@google.com
>
> But you can already flip that switch in your config
> (CONFIG_KFENCE_STATIC_KEYS=n), which we recommend as a default now.
>
> As a side-effect it'd also make your QEMU TCG tests pass.
Cool! Thanks for the update!
And about the other panic that I was getting it seems to be fixed by
this one:
https://lore.kernel.org/lkml/YW6N2qXpBU3oc50q@arighi-desktop/T/#u
-Andrea
prev parent reply other threads:[~2021-10-20 6:11 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-10 13:53 Andrea Righi
2021-10-11 6:00 ` Marco Elver
2021-10-11 6:32 ` Andrea Righi
2021-10-11 6:48 ` Marco Elver
2021-10-11 7:10 ` Andrea Righi
2021-10-11 7:19 ` Dmitry Vyukov
2021-10-11 9:23 ` Andrea Righi
2021-10-11 9:52 ` Andrea Righi
2021-10-11 10:03 ` Marco Elver
2021-10-11 14:42 ` Andrea Righi
2021-10-11 15:00 ` Dmitry Vyukov
2021-10-11 15:11 ` Andrea Righi
2021-10-11 15:16 ` Dmitry Vyukov
2021-10-20 6:00 ` Marco Elver
2021-10-20 6:11 ` Andrea Righi [this message]
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