From: Mark Rutland <mark.rutland@arm.com>
To: Marco Elver <elver@google.com>
Cc: Will Deacon <will@kernel.org>,
"Paul E. McKenney" <paulmck@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Anders Roxell <anders.roxell@linaro.org>,
Andrew Morton <akpm@linux-foundation.org>,
Alexander Potapenko <glider@google.com>,
Dmitry Vyukov <dvyukov@google.com>, Jann Horn <jannh@google.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
kasan-dev <kasan-dev@googlegroups.com>,
rcu@vger.kernel.org, Peter Zijlstra <peterz@infradead.org>,
Tejun Heo <tj@kernel.org>, Lai Jiangshan <jiangshanlai@gmail.com>,
linux-arm-kernel@lists.infradead.org, boqun.feng@gmail.com,
tglx@linutronix.de
Subject: Re: linux-next: stall warnings and deadlock on Arm64 (was: [PATCH] kfence: Avoid stalling...)
Date: Wed, 25 Nov 2020 10:28:49 +0000 [thread overview]
Message-ID: <20201125102849.GB70906@C02TD0UTHF1T.local> (raw)
In-Reply-To: <20201125094517.GA1359135@elver.google.com>
On Wed, Nov 25, 2020 at 10:45:17AM +0100, Marco Elver wrote:
> On Tue, Nov 24, 2020 at 07:30PM +0000, Mark Rutland wrote:
[...]
> > > I noticed there are a bunch of warnings in the log
> > > that might be relevant (see attached).
> >
> > > [ 91.184432] =============================
> > > [ 91.188301] WARNING: suspicious RCU usage
> > > [ 91.192316] 5.10.0-rc4-next-20201119-00002-g51c2bf0ac853 #25 Tainted: G W
> > > [ 91.197536] -----------------------------
> > > [ 91.201431] kernel/trace/trace_preemptirq.c:78 RCU not watching trace_hardirqs_off()!
> > > [ 91.206546]
> > > [ 91.206546] other info that might help us debug this:
> > > [ 91.206546]
> > > [ 91.211790]
> > > [ 91.211790] rcu_scheduler_active = 2, debug_locks = 0
> > > [ 91.216454] RCU used illegally from extended quiescent state!
> > > [ 91.220890] no locks held by swapper/0/0.
> > > [ 91.224712]
> > > [ 91.224712] stack backtrace:
> > > [ 91.228794] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 5.10.0-rc4-next-20201119-00002-g51c2bf0ac853 #25
> > > [ 91.234877] Hardware name: linux,dummy-virt (DT)
> > > [ 91.239032] Call trace:
> > > [ 91.242587] dump_backtrace+0x0/0x240
> > > [ 91.246500] show_stack+0x34/0x88
> > > [ 91.250295] dump_stack+0x140/0x1bc
> > > [ 91.254159] lockdep_rcu_suspicious+0xe4/0xf8
> > > [ 91.258332] trace_hardirqs_off+0x214/0x330
> > > [ 91.262462] trace_graph_return+0x1ac/0x1d8
> > > [ 91.266564] ftrace_return_to_handler+0xa4/0x170
> > > [ 91.270809] return_to_handler+0x1c/0x38
> > > [ 91.274826] default_idle_call+0x94/0x38c
> > > [ 91.278869] do_idle+0x240/0x290
> > > [ 91.282633] rest_init+0x1e8/0x2dc
> > > [ 91.286529] arch_call_rest_init+0x1c/0x28
> > > [ 91.290585] start_kernel+0x638/0x670
> >
> > Hmm... I suspect that arch_cpu_idle() is being traced here, and I reckon
> > we have to mark that and its callees as noinstr, since it doesn't seem
> > sane to have ftrace check whether RCU is watching for every function
> > call. Maybe Paul or Steve can correct me. ;)
>
> Yes, it's arch_cpu_idle().
>
> > If you still have the binary lying around, can you check whether
> > default_idle_call+0x94/0x38c is just after the call to arch_cpu_idle()?
> > If you could dump the asm around that, along with whatever faddr2line
> > tells you, that'd be a great help.
>
> I reran to be sure, with similar results. I've attached a
> syz-symbolize'd version of the warnings.
Thanks for confirming, and for the symbolized report.
I'll see about getting this fixed ASAP.
Thanks,
Mark.
next prev parent reply other threads:[~2020-11-25 10:29 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 13:53 [PATCH] kfence: Avoid stalling work queue task without allocations Marco Elver
2020-11-10 14:25 ` Dmitry Vyukov
2020-11-10 14:53 ` Marco Elver
2020-11-10 23:23 ` Anders Roxell
2020-11-11 8:29 ` Marco Elver
2020-11-11 13:38 ` Marco Elver
2020-11-11 18:05 ` Steven Rostedt
2020-11-11 18:23 ` Paul E. McKenney
2020-11-11 18:34 ` Marco Elver
2020-11-11 19:21 ` Paul E. McKenney
2020-11-11 20:21 ` Marco Elver
2020-11-12 0:11 ` Paul E. McKenney
2020-11-12 12:49 ` Marco Elver
2020-11-12 16:14 ` Marco Elver
2020-11-12 17:54 ` Paul E. McKenney
2020-11-12 18:12 ` Marco Elver
2020-11-12 20:00 ` Paul E. McKenney
2020-11-13 11:06 ` Marco Elver
2020-11-13 17:20 ` Paul E. McKenney
2020-11-13 17:57 ` Paul E. McKenney
2020-11-17 10:52 ` Marco Elver
2020-11-17 18:29 ` Paul E. McKenney
2020-11-18 22:56 ` Marco Elver
2020-11-18 23:38 ` Paul E. McKenney
2020-11-19 12:53 ` Marco Elver
2020-11-19 15:14 ` Paul E. McKenney
2020-11-19 17:02 ` Marco Elver
2020-11-19 18:48 ` Paul E. McKenney
2020-11-19 19:38 ` linux-next: stall warnings and deadlock on Arm64 (was: [PATCH] kfence: Avoid stalling...) Marco Elver
2020-11-19 21:35 ` Paul E. McKenney
2020-11-19 22:53 ` Will Deacon
2020-11-20 10:30 ` Mark Rutland
2020-11-20 14:03 ` Marco Elver
2020-11-23 19:32 ` Mark Rutland
2020-11-24 14:03 ` Marco Elver
2020-11-24 15:01 ` Paul E. McKenney
2020-11-24 19:43 ` Mark Rutland
2020-11-24 20:32 ` Steven Rostedt
2020-11-24 19:30 ` Mark Rutland
2020-11-25 9:45 ` Marco Elver
2020-11-25 10:28 ` Mark Rutland [this message]
2020-11-20 14:19 ` Marco Elver
2020-11-20 14:39 ` Paul E. McKenney
2020-11-20 15:22 ` Mark Rutland
2020-11-20 17:38 ` Paul E. McKenney
2020-11-20 18:02 ` Mark Rutland
2020-11-20 18:57 ` Paul E. McKenney
2020-11-20 15:26 ` Steven Rostedt
2020-11-20 18:17 ` Marco Elver
2020-11-20 18:57 ` Steven Rostedt
2020-11-20 19:16 ` Steven Rostedt
2020-11-20 19:22 ` Marco Elver
2020-11-20 19:27 ` [PATCH] kfence: Avoid stalling work queue task without allocations Steven Rostedt
2020-11-23 15:27 ` Marco Elver
2020-11-23 16:28 ` Steven Rostedt
2020-11-23 16:36 ` Steven Rostedt
2020-11-23 18:53 ` Marco Elver
2020-11-23 18:42 ` Steven Rostedt
2020-11-24 2:59 ` Boqun Feng
2020-11-24 3:44 ` Paul E. McKenney
2020-11-11 18:21 ` Paul E. McKenney
2020-11-11 15:01 ` Anders Roxell
2020-11-11 15:22 ` Marco Elver
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