kernel BUG at /build/buildd/linux-3.18.0/mm/slub.c:3334!

This change was made by a bot.

Does this bug prevent the system from booting?

When answered, please set this bug status back to "confirmed". Thank you.

Happens on my system too. I did a fresh install of Vivid daily two days ago (Feb 3), did a update/upgrade today (Feb 5), and after the reboot dmesg shows:

[ 11.252422] ------------[ cut here ]------------
[ 11.252475] kernel BUG at /build/buildd/linux-3.18.0/mm/slub.c:3334!
[ 11.252526] invalid opcode: 0000 [#1] SMP
[ 11.252564] Modules linked in: hid_generic hp_wmi sparse_keymap intel_rapl intel_soc_dts_thermal intel_powerclamp coretemp arc4 kvm crct10dif_pclmul crc32_pclmul ghash_clmulni_intel cryptd rtl8723be btcoexist rtl8723_common rtl_pci rtlwifi mac80211 usbhid i915 cfg80211 snd_hda_codec_hdmi serio_raw snd_soc_rt5640 snd_soc_rl6231 snd_hda_codec_realtek snd_hda_codec_generic snd_soc_core drm_kms_helper snd_compress snd_pcm_dmaengine snd_seq_midi lpc_ich rtsx_pci_ms snd_seq_midi_event drm memstick mei_txe snd_hda_intel mei snd_rawmidi snd_hda_controller snd_hda_codec iosf_mbi snd_hwdep i2c_algo_bit snd_pcm shpchp snd_seq wmi snd_seq_device snd_timer snd video dw_dmac hp_wireless dw_dmac_core int3403_thermal int3400_thermal acpi_thermal_rel soundcore intel_smartconnect i2c_hid hid bnep rfcomm snd_soc_sst_acpi
[ 11.253253] rfkill_gpio i2c_designware_platform pwm_lpss_platform i2c_designware_core parport_pc spi_pxa2xx_platform 8250_dw ppdev pwm_lpss lp parport btusb bluetooth joydev mac_hid nls_iso8859_1 mmc_block rtsx_pci_sdmmc psmouse rtsx_pci sdhci_acpi sdhci
[ 11.253463] CPU: 1 PID: 868 Comm: thermald Not tainted 3.18.0-12-generic #13-Ubuntu
[ 11.253521] Hardware name: Hewlett-Packard HP Stream Notebook PC 13/802A, BIOS F.05 11/28/2014
[ 11.253586] task: ffff8800772dda00 ti: ffff8800720a8000 task.ti: ffff8800720a8000
[ 11.253642] RIP: 0010:[<ffffffff811d4093>] [<ffffffff811d4093>] kfree+0x143/0x150
[ 11.253707] RSP: 0018:ffff8800720abe18 EFLAGS: 00010246
[ 11.253748] RAX: 01ffff0000000400 RBX: ffffffff811f075d RCX: 0000000000000ec6
[ 11.253801] RDX: 0000000000000000 RSI: ffff880076c96800 RDI: ffffffff811f075d
[ 11.253854] RBP: ffff8800720abe38 R08: 0000000000016800 R09: ffffea0000047c00
[ 11.253908] R10: ffffffff8145dc27 R11: 0000000000000246 R12: 00007fff15acbae8
[ 11.253962] R13: ffffffffc03787ea R14: 0000000080087304 R15: 00007fff15acbae8
[ 11.254017] FS: 00007f9c1a78c840(0000) GS:ffff880076c80000(0000) knlGS:0000000000000000
[ 11.254078] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 11.254122] CR2: 00007f9c1a803060 CR3: 00000000797f5000 CR4: 00000000001007e0
[ 11.254176] Stack:
[ 11.254193] 00007fff15acbae8 0000000000000000 00007fff15acbae8 ffff880077b702f8
[ 11.254258] ffff8800720abea8 ffffffffc03787ea ffff88003f4fe6f8 ffff88007713b020
[ 11.254322] 0000000000000000 ffff8800720abe88 0000000000000000 ffffffff811f075d
[ 11.254386] Call Trace:
[ 11.254426] [<ffffffffc03787ea>] acpi_thermal_rel_ioctl+0x21a/0xa30 [acpi_thermal_rel]
[ 11.254495] [<ffffffff811f075d>] ? ftrace_raw_event_do_sys_open+0x8d/0xe0
[ 11.254550] [<ffffffff81208078>] do_vfs_ioctl+0x2c8/0x4a0
[ 11.254595] [<ffffffff81204826>] ? final_putname+0x26/0x50
[ 11.254640] [<ffffffff81204ac9>] ? putname+0x29/0x40
[ 11.254681] [<ffffffff811f2ad9>] ? do_sys_open+0x1b9/0x280
[ 11.254725] [<ffffff...

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v3.19 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'.
Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.19-rc7-vivid/

I've installed v3.19-rc7-vivid (thus now running 3.19.0-031900rc7-generic) and the dmesg message is gone now. Good!

FWIW: with

linux-headers-3.19.0-031900rc7-generic_3.19.0-031900rc7.201502020035_amd64.deb
linux-image-3.19.0-031900rc7-generic_3.19.0-031900rc7.201502020035_amd64.deb

I did

sudo dpkg -i *031900rc7-generic_3.19.0*deb

and the kernel itself went OK, but the headers didn't:

Errors were encountered while processing:
 linux-headers-3.19.0-031900rc7-generic

But could be a noob thing, but I can't find it. Tips welcome

Full log:

sander@superstreamer:~/Downloads/3.19.0-031900rc7$ sudo dpkg -i *deb

(Reading database ... 187321 files and directories currently installed.)
Preparing to unpack linux-headers-3.19.0-031900rc7-generic_3.19.0-031900rc7.201502020035_amd64.deb ...
Unpacking linux-headers-3.19.0-031900rc7-generic (3.19.0-031900rc7.201502020035) over (3.19.0-031900rc7.201502020035) ...
Preparing to unpack linux-image-3.19.0-031900rc7-generic_3.19.0-031900rc7.201502020035_amd64.deb ...
Done.
Unpacking linux-image-3.19.0-031900rc7-generic (3.19.0-031900rc7.201502020035) over (3.19.0-031900rc7.201502020035) ...
Examining /etc/kernel/postrm.d .
run-parts: executing /etc/kernel/postrm.d/initramfs-tools 3.19.0-031900rc7-generic /boot/vmlinuz-3.19.0-031900rc7-generic
run-parts: executing /etc/kernel/postrm.d/zz-update-grub 3.19.0-031900rc7-generic /boot/vmlinuz-3.19.0-031900rc7-generic
dpkg: dependency problems prevent configuration of linux-headers-3.19.0-031900rc7-generic:
 linux-headers-3.19.0-031900rc7-generic depends on linux-headers-3.19.0-031900rc7; however:
  Package linux-headers-3.19.0-031900rc7 is not installed.

dpkg: error processing package linux-headers-3.19.0-031900rc7-generic (--install):
 dependency problems - leaving unconfigured
Setting up linux-image-3.19.0-031900rc7-generic (3.19.0-031900rc7.201502020035) ...
Running depmod.
update-initramfs: deferring update (hook will be called later)
Not updating initrd symbolic links since we are being updated/reinstalled
(3.19.0-031900rc7.201502020035 was configured last, according to dpkg)
Not updating image symbolic links since we are being updated/reinstalled
(3.19.0-031900rc7.201502020035 was configured last, according to dpkg)
Examining /etc/kernel/postinst.d.
run-parts: executing /etc/kernel/postinst.d/apt-auto-removal 3.19.0-031900rc7-generic /boot/vmlinuz-3.19.0-031900rc7-generic
run-parts: executing /etc/kernel/postinst.d/initramfs-tools 3.19.0-031900rc7-generic /boot/vmlinuz-3.19.0-031900rc7-generic
update-initramfs: Generating /boot/initrd.img-3.19.0-031900rc7-generic
run-parts: executing /etc/kernel/postinst.d/pm-utils 3.19.0-031900rc7-generic /boot/vmlinuz-3.19.0-031900rc7-generic
run-parts: executing /etc/kernel/postinst.d/update-notifier 3.19.0-031900rc7-generic /boot/vmlinuz-3.19.0-031900rc7-generic
run-parts: executing /etc/kernel/postinst.d/zz-update-grub 3.19.0-031900rc7-generic /boot/vmlinuz-3.19.0-031900rc7-generic
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-3.19.0-031900rc7-generic
Found initrd image: /boot/initrd.img-3.19.0-031900rc7-generic
Found linux image: /boot/vmlinuz-3.18.0-12-generic
Found initrd image: /boot...

@myself:

It was a noob thing indeed:

I had

linux-headers-3.19.0-031900rc7-generic_3.19.0-031900rc7.201502020035_amd64.deb
linux-image-3.19.0-031900rc7-generic_3.19.0-031900rc7.201502020035_amd64.deb

and needed the "all.deb" file too:

linux-headers-3.19.0-031900rc7_3.19.0-031900rc7.201502020035_all.deb
linux-headers-3.19.0-031900rc7-generic_3.19.0-031900rc7.201502020035_amd64.deb
linux-image-3.19.0-031900rc7-generic_3.19.0-031900rc7.201502020035_amd64.deb

And with these three files the "sudo dpkg -i *deb" went fine.

Generic command to get and install the three needed debs (amd64, generic):

lynx --dump http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.19-rc7-vivid/ | grep -e all.deb -e "generic.*amd64" | awk '{ print "wget " $2 }' | /bin/sh
sudo dpkg -i *deb

Jacobvisick, as per http://www.asus.com/supportonly/Q501LA/HelpDesk_Download/ an update to your computer's buggy and outdated BIOS is available (209). If you update to this following https://help.ubuntu.com/community/BIOSUpdate does it change anything? If it doesn't, could you please both specify what happened, and provide the output of the following terminal command:
sudo dmidecode -s bios-version && sudo dmidecode -s bios-release-date

For more on BIOS updates and linux, please see https://help.ubuntu.com/community/ReportingBugs#Bug_reporting_etiquette .

Please note your current BIOS is already in the Bug Description, so posting this on the old BIOS would not be helpful. As well, you don't have to create a new bug report.

Once the BIOS is updated, and the information above is provided, then please mark this report Status Confirmed.

Thank you for your understanding.

FWIW:

I'm now running the latest 3.18 (3.18.0-13-generic) which arrived today (Feb 10), and no more slub.c messages in dmesg.

So ... was it solved in 3.18.0-13-generic?

Ouch, it's still there in 3.18.0-13-generic:

sander@superstreamer:~$ uname -a
Linux superstreamer 3.18.0-13-generic #14-Ubuntu SMP Fri Feb 6 09:55:14 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
sander@superstreamer:~$

sander@superstreamer:~$ dmesg | grep -i slub
[ 0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1
[ 26.373219] kernel BUG at /build/buildd/linux-3.18.0/mm/slub.c:3334!
[ 26.508415] kernel BUG at /build/buildd/linux-3.18.0/mm/slub.c:3334!
[ 26.644419] kernel BUG at /build/buildd/linux-3.18.0/mm/slub.c:3334!
[ 26.770748] kernel BUG at /build/buildd/linux-3.18.0/mm/slub.c:3334!
[ 26.887036] kernel BUG at /build/buildd/linux-3.18.0/mm/slub.c:3334!
[ 27.011276] kernel BUG at /build/buildd/linux-3.18.0/mm/slub.c:3334!
[ 27.129399] kernel BUG at /build/buildd/linux-3.18.0/mm/slub.c:3334!
[ 27.247595] kernel BUG at /build/buildd/linux-3.18.0/mm/slub.c:3334!
[ 27.369409] kernel BUG at /build/buildd/linux-3.18.0/mm/slub.c:3334!
[ 27.496308] kernel BUG at /build/buildd/linux-3.18.0/mm/slub.c:3334!
[ 27.617541] kernel BUG at /build/buildd/linux-3.18.0/mm/slub.c:3334!
sander@superstreamer:~$

full dmesg

I took a quick look at recent commits that affect drivers/thermal/int340x_thermal/acpi_thermal_rel.c and the following commit caught my attention:

commit 7b09406390e76df97c9f5f29c23a4f56d982f22c
Author: Ilkka Koskinen <email address hidden>
Date: Tue Dec 9 12:34:03 2014 -0800

    Thermal/int340x: Handle properly the case when _trt or _art acpi entry is missing

It seems to fix a kfree of an uninitialized pointer, which seems to be what is happening here.

I built a 3.18.0-13.14 test kernel with this additional commit and uploaded it here:
http://people.canonical.com/~henrix/lp1418286/v1/

Could you please take a look and see if it fixes the bug? Thanks!

Thanks! I'll do that tonight.

Question: should I install all four debs, so also the linux-image-extra?

> Question: should I install all four debs, so also the linux-image-extra?

Yes. Thanks!

OK, now running that new kernel. Well, at least I think it is, but it says:

$ uname -a
Linux superstreamer 3.18.0-13-generic #14-Ubuntu SMP Fri Feb 6 09:55:14 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

Made on Feb 6? Can that be right? There was no sign of "3.18.0-13.14~lp1418286v1" in my Grub menu, only 3.18.0-13. Is that good?

dmesg now shows 129 times this line

Request for unknown module key 'Magrathea: Glacier signing key: bf41f129406f110879b32f34256d25445a48cb14' err -11

... so that is a sign I do have another kernel. ;-)

Snippet from "sudo dpkg -i *deb':
"Setting up linux-image-extra-3.18.0-13-generic (3.18.0-13.14~lp1418286v1) ..."

So far no slub.c in dmesg

From the above, it looks like you are not running the test kernel. I don't think 'uname -a' would show the "lp1418286v1" string, but the build date should be Feb 17, not 6. (BTW, running something like 'dmesg|grep "Linux version"' should show that "~lp1418286v1" string).

So, it looks like the installation of the 4 .deb files failed, in particular the linux-image-3.18.0-13-generic* one. Could you please take a look at the output and see if you see any error? (The "Request for unknown module key..." lines seems to indicate that the linux-image-extra... package was indeed installed.)

Thanks.

Current situtation:

sander@superstreamer:~$ uptime && dmesg | grep -i -e "Linux version" -e slub
 22:22:32 up 2:59, 1 user, load average: 1,74, 0,90, 0,70
[ 0.000000] Linux version 3.18.0-13-generic (buildd@komainu) (gcc version 4.9.2 (Ubuntu 4.9.2-10ubuntu5) ) #14-Ubuntu SMP Fri Feb 6 09:55:14 UTC 2015 (Ubuntu 3.18.0-13.14-generic 3.18.5)
[ 0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1
sander@superstreamer:~$

So:
1) still no slub.c messages; that's good.
2) The "Linux version" does show "Ubuntu 3.18.0-13.14-generic". Is that your kernel version? I'll do the download & install procedure once again anyway:

lynx --dump http://people.canonical.com/~henrix/lp1418286/v1/ | grep http | egrep -e ".*deb" | awk '{ print "wget " $2 }' | /bin/sh

-rw-r--r-- 1 sander sander 9281220 feb 17 12:50 linux-headers-3.18.0-13_3.18.0-13.14~lp1418286v1_all.deb
-rw-r--r-- 1 sander sander 821582 feb 17 12:50 linux-headers-3.18.0-13-generic_3.18.0-13.14~lp1418286v1_amd64.deb
-rw-r--r-- 1 sander sander 16514422 feb 17 12:50 linux-image-3.18.0-13-generic_3.18.0-13.14~lp1418286v1_amd64.deb
-rw-r--r-- 1 sander sander 37643802 feb 17 12:50 linux-image-extra-3.18.0-13-generic_3.18.0-13.14~lp1418286v1_amd64.deb

sander@superstreamer:~/sander-card/kernel/henrix$ sudo dpkg -i *deb
[sudo] password for sander:
(Reading database ... 342416 files and directories currently installed.)
Preparing to unpack linux-headers-3.18.0-13_3.18.0-13.14~lp1418286v1_all.deb ...
Unpacking linux-headers-3.18.0-13 (3.18.0-13.14~lp1418286v1) over (3.18.0-13.14~lp1418286v1) ...
Preparing to unpack linux-headers-3.18.0-13-generic_3.18.0-13.14~lp1418286v1_amd64.deb ...
Unpacking linux-headers-3.18.0-13-generic (3.18.0-13.14~lp1418286v1) over (3.18.0-13.14~lp1418286v1) ...
Preparing to unpack linux-image-3.18.0-13-generic_3.18.0-13.14~lp1418286v1_amd64.deb ...
Done.
Unpacking linux-image-3.18.0-13-generic (3.18.0-13.14~lp1418286v1) over (3.18.0-13.14~lp1418286v1) ...
Examining /etc/kernel/postrm.d .
run-parts: executing /etc/kernel/postrm.d/initramfs-tools 3.18.0-13-generic /boot/vmlinuz-3.18.0-13-generic
run-parts: executing /etc/kernel/postrm.d/zz-update-grub 3.18.0-13-generic /boot/vmlinuz-3.18.0-13-generic
Preparing to unpack linux-image-extra-3.18.0-13-generic_3.18.0-13.14~lp1418286v1_amd64.deb ...
Unpacking linux-image-extra-3.18.0-13-generic (3.18.0-13.14~lp1418286v1) over (3.18.0-13.14~lp1418286v1) ...
Setting up linux-headers-3.18.0-13 (3.18.0-13.14~lp1418286v1) ...
Setting up linux-headers-3.18.0-13-generic (3.18.0-13.14~lp1418286v1) ...
Setting up linux-image-3.18.0-13-generic (3.18.0-13.14~lp1418286v1) ...
Running depmod.
update-initramfs: deferring update (hook will be called later)
Not updating initrd symbolic links since we are being updated/reinstalled
(3.18.0-13.14~lp1418286v1 was configured last, according to dpkg)
Not updating image symbolic links since we are being updated/reinstalled
(3.18.0-13.14~lp1418286v1 was configured last, according to dpkg)
Examining /etc/kernel/postinst.d.
run-parts: executing /etc/kernel/postinst.d/apt-auto-removal 3.18.0-13-generic /boot/vmlinuz-3.18.0-13-generic
run-parts: executing /etc/kernel/post...

Rebooted, and same result

sander@superstreamer:~$ uname -a
Linux superstreamer 3.18.0-13-generic #14-Ubuntu SMP Fri Feb 6 09:55:14 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
sander@superstreamer:~$

sander@superstreamer:~$ dpkg -l | grep -e linux-image- -e "^|"
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
rc linux-image-3.18.0-12-generic 3.18.0-12.13 amd64 Linux kernel image for version 3.18.0 on 64 bit x86 SMP
ii linux-image-3.18.0-13-generic 3.18.0-13.14~lp1418286v1 amd64 Linux kernel image for version 3.18.0 on 64 bit x86 SMP
ii linux-image-3.19.0-031900-generic 3.19.0-031900.201502091451 amd64 Linux kernel image for version 3.19.0 on 64 bit x86 SMP
ii linux-image-3.19.0-031900-lowlatency 3.19.0-031900.201502091451 amd64 Linux kernel image for version 3.19.0 on 64 bit x86 SMP
ii linux-image-3.19.0-031900rc7-generic 3.19.0-031900rc7.201502020035 amd64 Linux kernel image for version 3.19.0 on 64 bit x86 SMP
ii linux-image-3.19.0-031900rc7-lowlatency 3.19.0-031900rc7.201502020035 amd64 Linux kernel image for version 3.19.0 on 64 bit x86 SMP
ii linux-image-3.19.0-994-generic 3.19.0-994.201502112105 amd64 Linux kernel image for version 3.19.0 on 64 bit x86 SMP
ii linux-image-3.19.0-999-generic 3.19.0-999.201502142105 amd64 Linux kernel image for version 3.19.0 on 64 bit x86 SMP
rc linux-image-extra-3.18.0-12-generic 3.18.0-12.13 amd64 Linux kernel extra modules for version 3.18.0 on 64 bit x86 SMP
ii linux-image-extra-3.18.0-13-generic 3.18.0-13.14~lp1418286v1 amd64 Linux kernel extra modules for version 3.18.0 on 64 bit x86 SMP
ii linux-image-generic 3.18.0.13.13 amd64 Generic Linux kernel image

I'll remove all 3.18 kernels, boot into 3.19, and reinstall your kernels.

sudo apt-get autoremove linux-image-3.18.0-12-generic linux-image-3.18.0-13-generic linux-image-extra-3.18.0-12-generic linux-image-extra-3.18.0-13-generic linux-image-generic

After the autoremove & purge, reboot into 3.19, and a fresh install of your kernel debs, things look better:

sander@superstreamer:~$ dmesg | grep -i -e "Linux version" -e slub
[ 0.000000] Linux version 3.18.0-13-generic (root@gloin) (gcc version 4.9.2 (Ubuntu 4.9.2-10ubuntu5) ) #14 SMP Tue Feb 17 11:13:29 UTC 2015 (Ubuntu 3.18.0-13.14~lp1418286v1-generic 3.18.5)
[ 0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1

That's your kernel, right?

sander@superstreamer:~$ uname -a
Linux superstreamer 3.18.0-13-generic #14 SMP Tue Feb 17 11:13:29 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

Looks good too, doesn't it?

sander@superstreamer:~$ dmesg | grep -i glacier
[ 6.976306] Loaded X.509 cert 'Magrathea: Glacier signing key: bf41f129406f110879b32f34256d25445a48cb14'
sander@superstreamer:~$

No more Glacier messages. Hooray!

So: installing the kernel now looks good. Sorry for the noise.

I'll now keep the kernel running for a few hours and check for slub again.

Thank you.

After 24 hours of use, still no slub.c error message in dmesg.

$ dmesg | grep -i slub
[ 0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1

[ 0.000000] Linux version 3.18.0-13-generic (root@gloin) (gcc version 4.9.2 (Ubuntu 4.9.2-10ubuntu5) ) #14 SMP Tue Feb 17 11:13:29 UTC 2015 (Ubuntu 3.18.0-13.14~lp1418286v1-generic 3.18.5)

Awesome, thanks for testing. The kernel currently in -proposed is 3.18.0-14.15 and it's likely the last 3.18 kernel for Vivid -- the next one should already be a 3.19 kernel. Since 3.19 kernel already contains the fix for this bug, I don't think there's a need to actually SRU the fix as it will not actually be uploaded.

I'm changing the bug status to 'Triagged'; feel free to change it to 'Fix released' once you get a 3.19 kernel.

I am using the 3.19.0-031900 kernel with Ubuntu 14.04 and I am seeing the 'Magrathea' message in dmesg:

$ dmesg -T|grep -E "(319|Magra)"
[Sat Mar 7 11:39:12 2015] Linux version 3.19.0-031900-generic (kernel@tangerine) (gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) ) #201502091451 SMP Mon Feb 9 14:52:52 UTC 2015
[Sat Mar 7 11:39:12 2015] Command line: BOOT_IMAGE=/boot/vmlinuz-3.19.0-031900-generic root=UUID=034f0162-ec48-4103-8f24-b15f1fd1a08d ro find_preseed=/preseed.cfg noprompt quiet
[Sat Mar 7 11:39:12 2015] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-3.19.0-031900-generic root=UUID=034f0162-ec48-4103-8f24-b15f1fd1a08d ro find_preseed=/preseed.cfg noprompt quiet
[Sat Mar 7 11:39:13 2015] usb usb1: Manufacturer: Linux 3.19.0-031900-generic ehci_hcd
[Sat Mar 7 11:39:13 2015] usb usb2: Manufacturer: Linux 3.19.0-031900-generic uhci_hcd
[Sat Mar 7 11:39:13 2015] Loaded X.509 cert 'Magrathea: Glacier signing key: 7271576a09d86ef244371b0633e47abb75b89d'
[Sat Mar 7 11:39:13 2015] Request for unknown module key 'Magrathea: Glacier signing key: 007271576a09d86ef244371b0633e47abb75b89d' err -11
[... Magrathea message repeated many many times! ...]