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
[<c011bb5c>] warn_on_slowpath+0x3c/0x50
[<c013b0f9>] ? __lock_acquire+0x219/0xfa0
[<c013b0f9>] ? __lock_acquire+0x219/0xfa0
[<c012c2c8>] ? __kernel_text_address+0x8/0x20
[<c0104fce>] ? dump_trace+0xce/0x120
[<c010a56c>] ? save_stack_trace+0x1c/0x40
[<c0138659>] ? save_trace+0x39/0xa0
[<c013a3d1>] ? mark_lock+0x61/0x540
[<c013bb49>] __lock_acquire+0xc69/0xfa0
[<c012b46a>] ? __cancel_work_timer+0x5a/0x140
[<c01082ac>] ? native_sched_clock+0x5c/0xb0
[<c013beee>] lock_acquire+0x6e/0x90
[<c02a8e23>] ? ata_scsi_error+0x33/0x6a0
[<c02e4946>] _spin_lock_irqsave+0x26/0x60
[<c02a8e23>] ? ata_scsi_error+0x33/0x6a0
[<c02a4ee0>] ? ata_bmdma_error_handler+0x0/0x50
[<c02a8e23>] ata_scsi_error+0x33/0x6a0
[<c02e249a>] ? schedule+0x27a/0x410
[<c0256dd1>] ? __scsi_iterate_devices+0x51/0x70
[<c025c681>] ? scsi_run_host_queues+0x21/0x30
[<c025ae5e>] scsi_error_handler+0x9e/0x4e0
[<c02e249a>] ? schedule+0x27a/0x410
[<c025adc0>] ? scsi_error_handler+0x0/0x4e0
[<c012dd86>] kthread+0x36/0x60
[<c012dd50>] ? kthread+0x0/0x60
[<c0104c27>] 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
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;
