linux-kernel - Re: suspend-related lockdep warning

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <200712022133.24420.rjw@sisk.pl>
Date:	Sun, 2 Dec 2007 21:33:23 +0100
From:	"Rafael J. Wysocki" <rjw@...k.pl>
To:	Pavel Machek <pavel@....cz>,
	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Ingo Molnar <mingo@...e.hu>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	linux-kernel@...r.kernel.org
Subject: Re: suspend-related lockdep warning

On Saturday, 1 of December 2007, Pavel Machek wrote:
> Hi!
> 
> > 2.6.24-rc3-mm2 (which will be released if it boots on two more machines and
> > if I stay awake) will say this during suspend-to-RAM on the Vaio:
> > 
> > [   91.876445] Syncing filesystems ... done.
> > [   92.382595] Freezing user space processes ... WARNING: at kernel/lockdep.c:2662 check_flags()
> > [   92.384000] Pid: 1925, comm: dbus-daemon Not tainted 2.6.24-rc3-mm2 #32
> > [   92.384177]  [<c0104a74>] show_trace_log_lvl+0x12/0x25
> > [   92.384335]  [<c01052ff>] show_trace+0xd/0x10
> > [   92.384469]  [<c01059be>] dump_stack+0x55/0x5d
> > [   92.384605]  [<c0136a29>] check_flags+0x7f/0x11a
> > [   92.384746]  [<c0139cfb>] lock_acquire+0x3a/0x86
> > [   92.384886]  [<c031f4de>] _spin_lock+0x26/0x53
> > [   92.385023]  [<c0141d3b>] refrigerator+0x13/0xc8
> > [   92.385163]  [<c01274c8>] get_signal_to_deliver+0x32/0x3fb
> > [   92.385326]  [<c01030f4>] do_notify_resume+0x8c/0x699
> > [   92.385476]  [<c0103c18>] work_notifysig+0x13/0x1b
> > [   92.385620]  =======================
> > [   92.385719] irq event stamp: 309
> > [   92.385809] hardirqs last  enabled at (309): [<c0103c79>] syscall_exit_work+0x11/0x26
> > [   92.386045] hardirqs last disabled at (308): [<c0103b42>] syscall_exit+0x14/0x25
> > [   92.386265] softirqs last  enabled at (0): [<c011bea5>] copy_process+0x374/0x130e
> > [   92.386491] softirqs last disabled at (0): [<00000000>] 0x0
> > [   92.392457] (elapsed 0.00 seconds) done.
> > [   92.392581] Freezing remaining freezable tasks ... (elapsed 0.00 seconds) done.
> > [   92.392882] PM: Entering mem sleep
> > [   92.392974] Suspending console(s)
> > 
> > this has been happening for quite some time and might even be happening in
> > mainline.  
> 
> Is it complaining that we entered refrigerator with irqs disabled?

Or that someone else called task_lock() with irqs disabled at one point ...

Hm, perhaps it's related to kernel preemption.  Andrew, I guess the kernel is
preemptible?

Greetings,
Rafael
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/