From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: v2.6.25: WARNING: at kernel/lockdep.c:2437 __lock_acquire+0xc69/0xfa0() Date: Thu, 24 Apr 2008 12:01:53 +0900 Message-ID: <480FF821.9050208@gmail.com> References: <19f34abd0804200329j3308b081vc0732c3ec5c0b721@mail.gmail.com> <1208782090.7115.179.camel@twins> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------070608030503030504060900" Return-path: Received: from an-out-0708.google.com ([209.85.132.247]:14531 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753110AbYDXDCF (ORCPT ); Wed, 23 Apr 2008 23:02:05 -0400 Received: by an-out-0708.google.com with SMTP id d31so781557and.103 for ; Wed, 23 Apr 2008 20:02:02 -0700 (PDT) In-Reply-To: <1208782090.7115.179.camel@twins> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Peter Zijlstra Cc: Vegard Nossum , LKML , Jeff Garzik , Ingo Molnar , IDE/ATA development list , Alan Cox This is a multi-part message in MIME format. --------------070608030503030504060900 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Peter Zijlstra wrote: > On Sun, 2008-04-20 at 12:29 +0200, Vegard Nossum wrote: >> Hi, >> >> This appears in clean v2.6.25: >> >> ------------[ cut here ]------------ >> WARNING: at kernel/lockdep.c:2437 __lock_acquire+0xc69/0xfa0() >> Pid: 1002, comm: scsi_eh_4 Not tainted 2.6.25 #379 >> [] warn_on_slowpath+0x3c/0x50 >> [] ? __lock_acquire+0x219/0xfa0 >> [] ? __lock_acquire+0x219/0xfa0 >> [] ? __kernel_text_address+0x8/0x20 >> [] ? dump_trace+0xce/0x120 >> [] ? save_stack_trace+0x1c/0x40 >> [] ? save_trace+0x39/0xa0 >> [] ? mark_lock+0x61/0x540 >> [] __lock_acquire+0xc69/0xfa0 >> [] ? __cancel_work_timer+0x5a/0x140 >> [] ? native_sched_clock+0x5c/0xb0 >> [] lock_acquire+0x6e/0x90 >> [] ? ata_scsi_error+0x33/0x6a0 >> [] _spin_lock_irqsave+0x26/0x60 >> [] ? ata_scsi_error+0x33/0x6a0 >> [] ? ata_bmdma_error_handler+0x0/0x50 >> [] ata_scsi_error+0x33/0x6a0 >> [] ? schedule+0x27a/0x410 >> [] ? __scsi_iterate_devices+0x51/0x70 >> [] ? scsi_run_host_queues+0x21/0x30 >> [] scsi_error_handler+0x9e/0x4e0 >> [] ? schedule+0x27a/0x410 >> [] ? scsi_error_handler+0x0/0x4e0 >> [] kthread+0x36/0x60 >> [] ? kthread+0x0/0x60 >> [] kernel_thread_helper+0x7/0x10 >> ======================= >> ---[ end trace 5e5d737e76fd4940 ]--- > > Indeed, quite easy to reproduce: > > diff --git a/kernel/lockdep.c b/kernel/lockdep.c > index 81a4e4a..33901ef 100644 > --- a/kernel/lockdep.c > +++ b/kernel/lockdep.c > @@ -2434,6 +2434,13 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass, > * the hash, not class->key. > */ > id = class - lock_classes; > + if (id >= MAX_LOCKDEP_KEYS) { > + spinlock_t *slock = container_of(lock, spinlock_t, dep_map); > + > + printk(KERN_EMERG "magic: %x\n", slock->magic); > + printk(KERN_EMERG "class: %p\n", class); > + printk(KERN_EMERG "id: %u\n", id); > + } > if (DEBUG_LOCKS_WARN_ON(id >= MAX_LOCKDEP_KEYS)) > return 0; > > > > gives me: > > ata3: PATA max PIO4 cmd 0x1e8 ctl 0x3ee irq 11 > magic: c050cf60 > class: c7c20e54 > id: 2265185251 > ------------[ cut here ]------------ > WARNING: at /mnt/md0/src/linux-2.6-2/kernel/lockdep.c:2444 > __lock_acquire+0x57b/0xfd0() > > > Looks like someone is stomping on the spinlock or just passing us > garbage. Does the attached patch help? -- tejun --------------070608030503030504060900 Content-Type: text/x-patch; name="legacy-fix.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="legacy-fix.patch" diff --git a/drivers/ata/pata_legacy.c b/drivers/ata/pata_legacy.c index 7af4b29..f7ba234 100644 --- a/drivers/ata/pata_legacy.c +++ b/drivers/ata/pata_legacy.c @@ -1037,6 +1037,7 @@ static __init int legacy_init_one(struct legacy_probe *probe) return 0; } } + ata_host_detach(host); fail: platform_device_unregister(pdev); return ret; --------------070608030503030504060900--