Re: [Xen-devel] Udev or XEN bug?

Pasi Kärkkäinen
Sun, 20 Jun 2010 09:05:24 -0000

On Sat, Jun 19, 2010 at 06:50:43PM +0200, Stephan Seitz
wrote:
> Hi!
>
> I???m usingen Debian/Testing with xen-hypervisor-4.0-amd64. Kernel for
> Dom0 is 2.6.34 with xen-patches-2.6.34-1.tar.bz2, kernel for DomU is the
> standard 2.6.34.
>
> With all udev version since 153-2, I can???t start my DomU. The following
> oops is happening:
>

Yeah, this is a known issue, and many people have seen it with new udev
versions.

See these emails for earlier discussion:
http://lists.xensource.com/archives/html/xen-devel/2010-05/msg01462.html
http://lists.xensource.com/archives/html/xen-devel/2010-05/msg01475.html

Also a friend of mine (CC) wrote this RFC-patch:
http://www.axu.tm/~ams/xen.diff.txt

Jeremy: Can we get a fix committed to xen/stable-2.6.32.x (and I guess to
xen/stable-2.6.31.x aswell) ?

Jan: Did you guys sort this out in Novell kernels already?

-- Pasi


> <1>1 2010-06-19T10:05:09.833919+02:00 osgiliath kernel - - - [
966.651574] BUG: unable to handle kernel NULL pointer dereference at
0000000000000110
> <1>1 2010-06-19T10:05:09.833927+02:00 osgiliath kernel - - - [
966.652006] IP: [<ffffffff812a1818>] netback_uevent+0x74/0x98
> <4>1 2010-06-19T10:05:09.833929+02:00 osgiliath kernel - - - [
> 966.652006] PGD c7b8a067 PUD d1dff067 PMD 0 <0>1
> 2010-06-19T10:05:09.833932+02:00 osgiliath kernel - - - [  966.652006]
> Oops: 0000 [#1] SMP <0>1 2010-06-19T10:05:09.833934+02:00 osgiliath
> kernel - - - [  966.652006] last sysfs file:
> /sys/devices/xen-backend/vif-1-1/uevent
> <4>1 2010-06-19T10:05:09.833936+02:00 osgiliath kernel - - - [
> 966.652006] CPU 0 <4>1 2010-06-19T10:05:09.833945+02:00 osgiliath
kernel
> - - - [  966.652006] Modules linked in: microcode nfsd exportfs nfs lockd
> auth_rpcgss sunrpc fus
> e lrw gf128mul it87 hwmon_vid coretemp joydev saa7134_alsa snd_pcm_oss
snd_mixer_oss snd_hda_codec_atihdmi tuner tea5767 tda8290 tuner_xc2028 xc5000 td
> a9887 tuner_simple tuner_types mt20xx snd_hda_intel tea5761 snd_hda_codec
> snd_pcm snd_seq_dummy saa7134 snd_seq_oss ir_common snd_seq_midi
> v4l2_common snd_rawmidi videodev snd_seq_midi_event v4l1_compat snd_seq
> v4l2_compat_ioctl32 videobuf_dma_sg videobuf_core 8250_pnp snd_timer
> snd_seq_device 8250 ir
> _core serial_core tveeprom floppy snd r8169 mii soundcore i2c_i801
snd_page_alloc
> <4>1 2010-06-19T10:05:09.833948+02:00 osgiliath kernel - - - [
> 966.652006] <4>1 2010-06-19T10:05:09.833951+02:00 osgiliath kernel -
- -
> [  966.652006] Pid: 12051, comm: udevd Not tainted 2.6.34-Dom0 #1
> EP45-DS3/EP45-DS3
> <4>1 2010-06-19T10:05:09.833954+02:00 osgiliath kernel - - - [
966.652006] RIP: e030:[<ffffffff812a1818>]  [<ffffffff812a1818>]
netback_uevent+0x74/0x
> 98
> <4>1 2010-06-19T10:05:09.833956+02:00 osgiliath kernel - - - [
966.652006] RSP: e02b:ffff8800d151dda8  EFLAGS: 00010246
> <4>1 2010-06-19T10:05:09.833959+02:00 osgiliath kernel - - - [
966.652006] RAX: ffff880001fa2b80 RBX: ffff8800dda72000 RCX: ffffffff812a1815
> <4>1 2010-06-19T10:05:09.833961+02:00 osgiliath kernel - - - [
966.652006] RDX: ffff880001f9b000 RSI: ffff880005784b30 RDI: ffff8800c5c4e000
> <4>1 2010-06-19T10:05:09.833964+02:00 osgiliath kernel - - - [
966.652006] RBP: ffff8800d151ddc8 R08: 0000000000000073 R09: 000000000000000a
> <4>1 2010-06-19T10:05:09.833966+02:00 osgiliath kernel - - - [
966.652006] R10: 00000000ffffffff R11: 00000000ffffffff R12: ffff8800c5c4e000
> <4>1 2010-06-19T10:05:09.833969+02:00 osgiliath kernel - - - [
966.652006] R13: 0000000000000000 R14: ffff8800ddbea400 R15: ffff8800c7a05000
> <4>1 2010-06-19T10:05:09.833972+02:00 osgiliath kernel - - - [
966.671383] FS:  00007f3830cac7a0(0000) GS:ffff880001f9b000(0000)
knlGS:000000000000000
> 0
> <4>1 2010-06-19T10:05:09.833974+02:00 osgiliath kernel - - - [
966.672401] CS:  e033 DS: 0000 ES: 0000 CR0: 000000008005003b
> <4>1 2010-06-19T10:05:09.833977+02:00 osgiliath kernel - - - [
966.673157] CR2: 0000000000000110 CR3: 00000000c14cc000 CR4: 0000000000002660
> <4>1 2010-06-19T10:05:09.833979+02:00 osgiliath kernel - - - [
966.673157] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> <4>1 2010-06-19T10:05:09.833982+02:00 osgiliath kernel - - - [
966.673157] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> <4>1 2010-06-19T10:05:09.833984+02:00 osgiliath kernel - - - [
966.673157] Process udevd (pid: 12051, threadinfo ffff8800d151c000, task
ffff8800bfc31e
> 00)
> <0>1 2010-06-19T10:05:09.833986+02:00 osgiliath kernel - - - [
966.673157] Stack:
> <4>1 2010-06-19T10:05:09.833989+02:00 osgiliath kernel - - - [
966.680349]  ffff8800dda72048 ffff8800c5c4e000 ffff8800dda72000 ffff8800dda72058
> <4>1 2010-06-19T10:05:09.833992+02:00 osgiliath kernel - - - [
966.680349] <0> ffff8800d151ddf8 ffffffff812919c8 ffff880001fa39b0
ffff8800dda72048
> <4>1 2010-06-19T10:05:09.833994+02:00 osgiliath kernel - - - [
966.680349] <0> ffff8800c5c4e000 ffff8800dfc06060 ffff8800d151de28
ffffffff81280939
> <0>1 2010-06-19T10:05:09.833996+02:00 osgiliath kernel - - - [
966.680349] Call Trace:
> <4>1 2010-06-19T10:05:09.833999+02:00 osgiliath kernel - - - [
966.680349]  [<ffffffff812919c8>] xenbus_uevent_backend+0x86/0x99
> <4>1 2010-06-19T10:05:09.834002+02:00 osgiliath kernel - - - [
966.680349]  [<ffffffff81280939>] dev_uevent+0x102/0x146
> <4>1 2010-06-19T10:05:09.834004+02:00 osgiliath kernel - - - [
966.680349]  [<ffffffff81280a82>] show_uevent+0x8c/0xe1
> <4>1 2010-06-19T10:05:09.834007+02:00 osgiliath kernel - - - [
966.680349]  [<ffffffff812805fb>] dev_attr_show+0x22/0x49
> <4>1 2010-06-19T10:05:09.834010+02:00 osgiliath kernel - - - [
966.680349]  [<ffffffff81074924>] ? __get_free_pages+0x12/0x49
> <4>1 2010-06-19T10:05:09.834013+02:00 osgiliath kernel - - - [
966.680349]  [<ffffffff810ef4a7>] sysfs_read_file+0xac/0x12e
> <4>1 2010-06-19T10:05:09.834015+02:00 osgiliath kernel - - - [
966.680349]  [<ffffffff810a2178>] vfs_read+0xaa/0x14b
> <4>1 2010-06-19T10:05:09.834018+02:00 osgiliath kernel - - - [
966.680349]  [<ffffffff810a22d2>] sys_read+0x45/0x6c
> <4>1 2010-06-19T10:05:09.834020+02:00 osgiliath kernel - - - [
966.680349]  [<ffffffff81004278>] system_call_fastpath+0x16/0x1b
> <4>1 2010-06-19T10:05:09.834023+02:00 osgiliath kernel - - - [
966.701922]  [<ffffffff81004210>] ? system_call+0x0/0x52
> <0>1 2010-06-19T10:05:09.834027+02:00 osgiliath kernel - - - [
966.704097] Code: 48 89 df 31 c0 e8 4d cf fe ff eb 37 48 89 c2 48 c7 c6 52 f7 52
81 4c 89 e7 31 c0 e8 5b 39 ed ff 4c 89 f7 e8 81 b7 df ff 4c 89 e7 <49> 8b
95 10 01 00 00 48 c7 c6 5c f7 52 81 31 c0 45 31 e4 e8 38
> <1>1 2010-06-19T10:05:09.834030+02:00 osgiliath kernel - - - [
966.706254] RIP  [<ffffffff812a1818>] netback_uevent+0x74/0x98
> <4>1 2010-06-19T10:05:09.834032+02:00 osgiliath kernel - - - [
966.706254]  RSP <ffff8800d151dda8>
> <0>1 2010-06-19T10:05:09.834034+02:00 osgiliath kernel - - - [
966.706254] CR2: 0000000000000110
> <4>1 2010-06-19T10:05:09.834037+02:00 osgiliath kernel - - - [
966.706386] ---[ end trace cdf4f473842f756c ]---
>
> Going back to 153-2 resolves the problem. Is this a bug in udev or in
> XEN?
>
> Shade and sweet water!
>
> 	Stephan
>
> --
> | Stephan Seitz             E-Mail: stse@fsing.rootsland.net |
> | PGP Public Keys: http://fsing.rootsland.net/~stse/pgp.html |



> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel