-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 All, I was installing Kbuntu 10.10 in a VirtualBox 3.2.12 VM when I ran into a BUG. My system kept running, but my Kbuntu install failed, and the VirtualBox instance was impossible to kill. (Killing the VirtualBox program with xkill removed the running window, but left an unkillable VirtualBox process "eating" one entire CPU in IO wait. [Picture attached.]) I''m running what''s close to the latest btrfs devel git kernel. ~/btrfs-unstable $ git log -n1 | head -n3 commit 83a50de97fe96aca82389e061862ed760ece2283 Author: Chris Mason <chris.mason@oracle.com> Date: Mon Dec 13 15:06:46 2010 -0500 Relevant dmesg output follows: [301928.294778] BUG: unable to handle kernel NULL pointer dereference at (null) [301928.294867] IP: [<c01222de>] kmap_atomic_prot+0x19/0xbd [301928.294931] *pde = 00000000 [301928.294965] Oops: 0000 [#1] PREEMPT SMP [301928.295006] last sysfs file: /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0A:00/power_supply/BATA/energy_now [301928.295006] Modules linked in: sky2 usbhid aes_i586 aes_generic fbcon tileblit font bitblit softcursor nfsd lockd nfs_acl auth_rpcgss ipv6 sunrpc coretemp snd_seq_oss snd_seq_midi_event snd_seq snd_pcm_oss sco bnep snd_mixer_oss binfmt_misc vboxnetadp vboxnetflt vboxdrv snd_usb_audio snd_usbmidi_lib snd_rawmidi snd_seq_device usbserial rfcomm l2cap hci_uart fuse cpufreq_powersave cpufreq_userspace cpufreq_stats cpufreq_conservative acpi_cpufreq mperf tun arc4 ecb i915 iwl3945 iwlcore snd_hda_codec_idt drm_kms_helper mac80211 snd_hda_intel drm snd_hda_codec snd_hwdep snd_pcm ppdev parport_pc cfg80211 i2c_algo_bit btusb cfbcopyarea snd_timer bluetooth snd panasonic_laptop video sg processor thermal parport container tpm_infineon i2c_i801 pcspkr ac rfkill battery backlight output cfbimgblt button cfbfillrect thermal_sys snd_page_alloc mmc_block pcmcia sdhci_pci sdhci firewire_ohci mmc_core yenta_socket firewire_core pcmcia_rsrc pcmcia_core dm_mod [last unloaded: microcode] [301928.295006] [301928.295006] Pid: 29063, comm: VirtualBox Not tainted 2.6.36+ #5 CF30-1/CF-30C3PAZBM [301928.295006] EIP: 0060:[<c01222de>] EFLAGS: 00010202 CPU: 0 [301928.295006] EIP is at kmap_atomic_prot+0x19/0xbd [301928.295006] EAX: 00000000 EBX: e41c2000 ECX: 00000163 EDX: 00000003 [301928.295006] ESI: 00001000 EDI: 00000000 EBP: e41c2dd8 ESP: e41c2dc8 [301928.295006] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 [301928.295006] Process VirtualBox (pid: 29063, ti=e41c2000 task=e4366300 task.ti=e41c2000) [301928.295006] Stack: [301928.295006] 84961163 e41c2ea8 00001000 00000000 e41c2de0 c0122395 e41c2df4 c019426b [301928.295006] <0> 00000200 00001000 00000000 e41c2e18 c040a1ae 00000200 0002ae00 0000002b [301928.295006] <0> 00001000 0002b000 e41c2ea8 c7f71400 e41c2ecc c040a7db c7f71000 e41c2ea8 [301928.295006] Call Trace: [301928.295006] [<c0122395>] ? kmap_atomic+0x13/0x15 [301928.295006] [<c019426b>] ? iov_iter_copy_from_user_atomic+0x3f/0x85 [301928.295006] [<c040a1ae>] ? btrfs_copy_from_user.clone.9+0x5a/0xa2 [301928.295006] [<c040a7db>] ? btrfs_file_aio_write+0x4d0/0x7e2 [301928.295006] [<c01e92e8>] ? aio_rw_vect_retry+0x6d/0x13b [301928.295006] [<c040a30b>] ? btrfs_file_aio_write+0x0/0x7e2 [301928.295006] [<c01e927b>] ? aio_rw_vect_retry+0x0/0x13b [301928.295006] [<c01e9e28>] ? aio_run_iocb+0x67/0xf7 [301928.295006] [<c01eabef>] ? do_io_submit+0x43e/0x602 [301928.295006] [<c01eadcb>] ? sys_io_submit+0x18/0x1a [301928.295006] [<c010291f>] ? sysenter_do_call+0x12/0x28 [301928.295006] [<c0610000>] ? slab_cpuup_callback+0x94/0xf0 [301928.295006] Code: 48 14 8b 40 08 a8 08 74 05 e8 f3 ee 4e 00 5b 5e 5d c3 55 89 e5 57 56 53 83 ec 04 0f 1f 44 00 00 89 e3 81 e3 00 f0 ff ff ff 43 14 <8b> 18 c1 eb 1e c1 e3 0a 8d b3 80 ce 8c c0 2b b3 0c d2 8c c0 81 [301928.295006] EIP: [<c01222de>] kmap_atomic_prot+0x19/0xbd SS:ESP 0068:e41c2dc8 [301928.295006] CR2: 0000000000000000 [301928.314422] ---[ end trace c670cac3e74dd1b4 ]--- [301928.314475] note: VirtualBox[29063] exited with preempt_count 2 -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.16 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQEcBAEBAgAGBQJNGsMUAAoJEIsblWe5kJ+jmfcH/iij3YBpTcywzIY+0jZpRmJH qz6PIGZhyEg4LQJdAhsh0b+ZK6mvciFoUkIFAITTXHG51S/EGUNb206n2JgLOsnI nSYmR/NZ9oI2p3GRCCQl7h1aTILUiT266oB4FCQlBMCA2P+9c+pIwrUzGnq3DrPI vIWBP4NIFQG9JKK5hYQAkCfzWO8WPFd/AoTVJXfHqBxCiQEBdmXQ7qDfGtskztTU Xlel9lLFiuLH1m2Qt3ynVPZl/EAsC3wSnzHZsjzvsEzAmyxNQeqnlFHilD6Lo5Sk daob6SIBXgY62Kv7L726uOjVWDg6BEMI6aafMCvJ2iCy8PsnAZMf+b9McDdB7gc=L61+ -----END PGP SIGNATURE-----