On 10/1/07, Cornelia Huck [off-list ref] wrote:
On Fri, 28 Sep 2007 18:32:32 +0200,
Pierre-Yves Paulus [off-list ref] wrote:
This looks more informational, thanks.
quoted
DEV: Unregistering device. ID = 'rfcomm0'
PM: Removing info for No Bus:rfcomm0
kobject_uevent_env
fill_kobj_path: path = '/class/tty/rfcomm0'
fill_kobj_path: path =
'/devices/pci0000:00/0000:00:0f.4/usb1/1-1/1-1.5/1-1.5.1/1-1.5.1:1.0/hci2/acl00126253F906'
kobject rfcomm0: cleaning up
device_create_release called for rfcomm0
Here rfcomm0 was unregistered and released.
quoted
bus bluetooth: remove device acl00126253F906
PM: Removing info for bluetooth:acl00126253F906
kobject_uevent_env
fill_kobj_path: path =
'/devices/pci0000:00/0000:00:0f.4/usb1/1-1/1-1.5/1-1.5.1/1-1.5.1:1.0/hci2/acl00126253F906'
kobject acl00126253F906: cleaning up
And here the corresponding physdev.
quoted
BUG: unable to handle kernel NULL pointer dereference at virtual address
00000000
printing eip:
c0249e29
*pde = 00000000
Oops: 0000 [#1]
Modules linked in: rfcomm l2cap battery ipv6 dm_snapshot dm_mirror
dm_mod softdog loop parport_pc parport floppy rtc pcspkr ac button
psmouse serio_raw snd_cs5535audio snd_ac97_codec ac97_bus snd_pcm
snd_timer snd soundcore snd_page_alloc geode_rng cs5535_gpio hci_usb
bluetooth geode_aes blkcipher tsdev evdev usbhid hid reiserfs ide_disk
generic amd74xx ide_core ohci_hcd sata_via ata_generic 8139cp libata
8139too usbcore mii scsi_mod thermal processor fan
CPU: 0
EIP: 0060:[<c0249e29>] Not tainted VLI
EFLAGS: 00010017 (2.6.23-rc8 #1)
EIP is at skb_dequeue+0x23/0x4a
eax: 00000282 ebx: 00000282 ecx: 00000000 edx: caf8ab8c
esi: c8428d48 edi: c8428c00 ebp: c8428c0c esp: c124ff60
ds: 007b es: 007b fs: 0000 gs: 0000 ss: 0068
Process events/0 (pid: 5, ti=c124e000 task=c1243500 task.ti=c124e000)
Stack: caf8ab8c c024b0a1 c8428c00 d02f4075 c8428d60 c020eb8d c08978a8
00000000
00000000 00000000 cf7ab680 c8428d48 c020eac4 00000000 c01279a9
c124ffb4
00000046 c1243500 cf7ab680 cf7ab680 c0127ffe c124ffd0 c01280b0
00000000
Call Trace:
[<c024b0a1>] skb_queue_purge+0x11/0x17
[<d02f4075>] rfcomm_tty_flush_buffer+0x1c/0x33 [rfcomm]
[<c020eb8d>] do_tty_hangup+0xc9/0x2d0
[<c020eac4>] do_tty_hangup+0x0/0x2d0
[<c01279a9>] run_workqueue+0x7d/0x103
[<c0127ffe>] worker_thread+0x0/0xbe
[<c01280b0>] worker_thread+0xb2/0xbe
[<c012a510>] autoremove_wake_function+0x0/0x35
[<c012a363>] kthread+0x36/0x5b
[<c012a32d>] kthread+0x0/0x5b
[<c0104e17>] kernel_thread_helper+0x7/0x10
=======================
rfcomm0 is already freed, maybe this code is still trying to access it?
quoted
Code: 89 42 0a 5b 5e 5f 5d c3 53 89 c2 9c 58 90 8d b4 26 00 00 00 00 89
c3 fa 90 8d b4 26 00 00 00 00 90 8b 0a 39 d1 75 04 31 c9 eb 17 <8b> 01
ff 4a 08 89 02 89 50 04 c7 01 00 00 00 00 c7 41 04 00 00
EIP: [<c0249e29>] skb_dequeue+0x23/0x4a SS:ESP 0068:c124ff60
WARNING: at lib/kref.c:33 kref_get()
[<c01c6db7>] kref_get+0x34/0x3d
[<c01c61a9>] kobject_get+0xf/0x13
[<c022578d>] get_device+0xe/0x14
[<c02257a6>] device_move+0x13/0x114
[<d02f4b7c>] rfcomm_tty_close+0x23/0x61 [rfcomm]
[<c020f88d>] release_dev+0x1c0/0x54e
[<d02f40e5>] rfcomm_dev_destruct+0x59/0x65 [rfcomm]
[<d02f4725>] rfcomm_dev_ioctl+0x329/0x4d0 [rfcomm]
[<c0130c96>] tick_program_event+0x2a/0x49
[<c0248124>] release_sock+0xc/0x74
[<c020fc22>] tty_release+0x7/0xa
[<c015dabd>] __fput+0x93/0x147
[<c015b66a>] filp_close+0x51/0x58
[<c02a8b0e>] __sched_text_start+0x1d6/0x245
[<c015c70b>] sys_close+0x54/0x83
[<c0103c72>] syscall_call+0x7/0xb
=======================
DEVICE: moving 'rfcomm0' to '<NULL>'
kobject <NULL>: cleaning up
device_create_release called for rfcomm0
But here someone still tries to move rfcomm0 around? It already is gone
and released... The code path has no reference on rfcomm0. (Well,
device_move() tries to get a reference on the device to be moved, but
that doesn't help since the device is already gone.)
This looks like a race inside rfcomm. The device_unregister() either
needs to be delayed until after device_move() has finished, or the
thread calling device_move() needs to have a reference. (device_move()
on an unregistered device should just fail but not oops.) Marcel?
-
Hi,
please try the attached patch.
or the one by marcel in http://lkml.org/lkml/2007/11/5/111
Please tell me the result, thanks.
Regards
dave