Re: kvm: unable to handle kernel NULL pointer dereference

Tobias Diedrich
2008-06-04T18:10:56Z

Avi Kivity wrote:
> Tobias Diedrich wrote:
> > Hi,
> >
> > I get the following Oops when trying to start qemu-kvm
> > (Debian/unstable kvm package version 60+dfsg-1) on my system:
> >
> > BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
> > IP: [<ffffffff8021d44f>] svm_vcpu_run+0x34/0x351
> >
>
>
> kvm-60 is quite old.

Maybe, but AFAIK a kernel NULL pointer dereference should not happen
and is always a kernel bug (Even if it may be triggered only by old
userspace)?
Maybe I'm wrong about that. :)

> Can you try kvm-69?

Sure.
*updating*
*trying*
I still get an Oops:
ii kvm 69+dfsg-1 Full virtualization on x86 hardware

BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
IP: [<ffffffff8021d44f>] svm_vcpu_run+0x34/0x351
PGD 7e01b067 PUD 7bc86067 PMD 0
Oops: 0000 [1] PREEMPT
CPU 0
Modules linked in: zaurus cdc_ether usbnet snd_hda_intel k8temp radeon drm snd_emu10k1_synth snd_emux_synth snd_seq_virmidi snd_seq_midi_emul snd_emu10k1 snd_seq_midi snd_rawmidi snd_ac97_codec ac97_bus snd_util_mem forcedeth emu10k1_gp gameport snd_hwdep pata_amd [last unloaded: snd_hda_intel]
Pid: 11113, comm: kvm Tainted: G W 2.6.26-rc4 #29
RIP: 0010:[<ffffffff8021d44f>] [<ffffffff8021d44f>] svm_vcpu_run+0x34/0x351
RSP: 0018:ffff81007866fc38 EFLAGS: 00010046
RAX: ffff810076d42040 RBX: 00000000fffffffc RCX: 0000000000000000
RDX: ffff810076d42040 RSI: ffff810079b41000 RDI: ffff810076d42040
RBP: ffff81007866fc88 R08: 0000000000000002 R09: 0000000000000001
R10: ffffffff804237e5 R11: ffff81007866fc88 R12: ffff810076d42040
R13: 0000000000000000 R14: ffff810079b41000 R15: 000000000000ae80
FS: 00000000419b1950(0063) GS:ffffffff808bc000(0000) knlGS:00000000f712b6c0
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000008 CR3: 0000000079b8d000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process kvm (pid: 11113, threadinfo ffff81007866e000, task ffff810019db8300)
Stack: ffff81007866fc68 ffff810076d42040 ffff810076d42040 ffff81007bc600a8
ffff810076d42040 00000000fffffffc ffff810076d42040 0000000000000000
ffff810079b41000 000000000000ae80 ffff81007866fcc8 ffffffff8020fa41
Call Trace:
[<ffffffff8020fa41>] kvm_arch_vcpu_ioctl_run+0x46a/0x6df
[<ffffffff8020ab98>] kvm_vcpu_ioctl+0xfd/0x3d0
[<ffffffff80293df1>] ? kmem_cache_free+0x6e/0x81
[<ffffffff8024cf89>] ? __dequeue_signal+0x1c/0x167
[<ffffffff802a322e>] vfs_ioctl+0x2a/0x77
[<ffffffff802a34d6>] do_vfs_ioctl+0x25b/0x270
[<ffffffff802a352d>] sys_ioctl+0x42/0x65
[<ffffffff8021fffb>] system_call_after_swapgs+0x7b/0x80

Code: 55 41 54 53 48 83 ec 28 48 89 7d b8 48 8b 87 50 15 00 00 48 8b 0d ba 9c 6f 00 c6 40 5c 00 48 8b 45 b8 83 b8 a0 00 00 00 00 75 0d <48> 8b 51 08 48 39 90 68 15 00 00 74 4f 8b 41 14 3b 41 10 76 1a
RIP [<ffffffff8021d44f>] svm_vcpu_run+0x34/0x351
RSP <ffff81007866fc38>
CR2: 0000000000000008
---[ end trace 5f8408bfe79febf6 ]---
note: kvm[11113] exited with preempt_count 1
BUG: sleeping function called from invalid context at kernel/rwsem.c:21
in_atomic():1, irqs_disabled():0
INFO: lockdep is turned off.
Pid: 11113, comm: kvm Tainted: G D W 2.6.26-rc4 #29

Call Trace:
[<ffffffff8025ed42>] ? __debug_show_held_locks+0x1b/0x24
[<ffffffff8023c1f4>] __might_sleep+0x10a/0x10c
[<ffffffff8067fa1f>] down_read+0x1d/0x45
[<ffffffff802624b3>] futex_wake+0x38/0x101
[<ffffffff8026345b>] do_futex+0xb8/0x916
[<ffffffff8025793f>] ? ktime_get_ts+0x49/0x4e
[<ffffffff80257955>] ? ktime_get+0x11/0x42
[<ffffffff8023aa37>] ? hrtick_start_fair+0x111/0x11e
[<ffffffff8023a7ea>] ? wakeup_preempt_entity+0x59/0x7d
[<ffffffff80263dae>] sys_futex+0xf5/0x113
[<ffffffff8023fc1e>] mm_release+0x85/0x8e
[<ffffffff8024385d>] exit_mm+0x1f/0xde
[<ffffffff8024502a>] do_exit+0x23c/0x68a
[<ffffffff80220ee3>] oops_begin+0x0/0x6e
[<ffffffff802337e0>] do_page_fault+0x6a8/0x760
[<ffffffff8068152d>] error_exit+0x0/0xa9
[<ffffffff804237e5>] ? __up_read+0x1c/0x93
[<ffffffff8021d44f>] ? svm_vcpu_run+0x34/0x351
[<ffffffff8020fa41>] ? kvm_arch_vcpu_ioctl_run+0x46a/0x6df
[<ffffffff8020ab98>] ? kvm_vcpu_ioctl+0xfd/0x3d0
[<ffffffff80293df1>] ? kmem_cache_free+0x6e/0x81
[<ffffffff8024cf89>] ? __dequeue_signal+0x1c/0x167
[<ffffffff802a322e>] ? vfs_ioctl+0x2a/0x77
[<ffffffff802a34d6>] ? do_vfs_ioctl+0x25b/0x270
[<ffffffff802a352d>] ? sys_ioctl+0x42/0x65
[<ffffffff8021fffb>] ? system_call_after_swapgs+0x7b/0x80

HTH,