[saucy][armhf] No early printk because there's no defined device tree binding for earlyprintk UART

Bug #1248233 reported by Manoj Iyer
This bug affects 1 person
Affects Status Importance Assigned to Milestone
linux (Ubuntu)
Paolo Pisati

Bug Description

SRU Justification:

Impact: earlyprintk doesn't work in mach-virt (qemu guest target for kvm on arm) because at boot time, the clock necessary to make pl011 serial port running is not added via device tree (and thus the serial console is not probed) - also see https://lists.gnu.org/archive/html/qemu-devel/2013-10/msg02427.html.

Fix: apply the attached patches and recompile a kernel.

Test case: try booting a patched (and an unpatched kernel) in kvm guest passing earlyprintk and NO console, and see if it emits any output.


There is no earlyprintk via the PL011 because there's no defined device tree binding for earlyprintk UART to get the PL011 to work you'll need to tweak the kernel a bit. kernel doesn't ever add the clock to its list, and then it refuses to probe for the PL011. This is a temporary fix, ideally the call should be done in some generic location rather than in every machine's init function.) The alternative would be for the kernel to be fixed to follow its own device tree binding documentation and not require clocks/clock-names properties on the pl011 node.

CVE References

Revision history for this message
Manoj Iyer (manjo) wrote :

This patch is a temporary fix.

Revision history for this message
Brad Figg (brad-figg) wrote : Missing required logs.

This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:

apport-collect 1248233

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

Changed in linux (Ubuntu):
status: New → Incomplete
tags: added: saucy
Changed in linux (Ubuntu):
importance: Undecided → Medium
tags: added: patch
Paolo Pisati (p-pisati)
description: updated
Revision history for this message
Manoj Iyer (manjo) wrote :

due to the nature of the issue encountered log files that will aid in diagnosing the problem might be missing.

Changed in linux (Ubuntu):
status: Incomplete → Confirmed
Revision history for this message
Brad Figg (brad-figg) wrote :

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-saucy' to 'verification-done-saucy'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

tags: added: verification-needed-saucy
Brad Figg (brad-figg)
tags: added: verification-done-saucy
removed: verification-needed-saucy
Revision history for this message
Manoj Iyer (manjo) wrote :

I can verify that the patch fixes the bug above, with this patch I am able to see messages at boot...

[ 0.000000] Booting Linux on physical CPU 0x0
[ 0.000000] Initializing cgroup subsys cpuset
[ 0.000000] Initializing cgroup subsys cpu
[ 0.000000] Initializing cgroup subsys cpuacct
[ 0.000000] Linux version 3.11.0-15-generic-lpae (buildd@kishi02) (gcc version 4.7.3 (Ubuntu/Linaro 4.7.3-7ubuntu3) ) #22-Ubuntu SMP Tue Dec 3 01:16:52 UTC 2013 (Ubuntu 3.11.0-15.22-generic-lpae 3.11.10)
[ 0.000000] CPU: ARMv7 Processor [413fc0f2] revision 2 (ARMv7), cr=30c7387d
[ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, PIPT instruction cache
[ 0.000000] Machine: Dummy Virtual Machine, model: linux,dummy-virt
[ 0.000000] cma: CMA: reserved 16 MiB at 36800000
[ 0.000000] Memory policy: ECC disabled, Data cache writealloc
[ 0.000000] psci: probing function IDs from device-tree
[ 0.000000] PERCPU: Embedded 9 pages/cpu @c11f5000 s14400 r8192 d14272 u36864
[ 0.000000] Built 1 zonelists in Zone order, mobility grouping on. Total pages: 260624

Revision history for this message
Launchpad Janitor (janitor) wrote :
Download full text (13.3 KiB)

This bug was fixed in the package linux - 3.11.0-15.23

linux (3.11.0-15.23) saucy; urgency=low

  [Brad Figg]

  * Release Tracking Bug
    - LP: #1259259

  [ Tim Gardner ]

  * [Config] Build-in ohci-pci
    - LP: #1244176

linux (3.11.0-15.22) saucy; urgency=low

  [Brad Figg]

  * Release Tracking Bug
    - LP: #1257092

  [ Andy Whitcroft ]

    - LP: #1252353

  [ Benjamin Tissoires ]

  * SAUCE: (no-up) HID: appleir: force input to be set
    - LP: #1244505

  [ John Johansen ]

  * SAUCE: (no-up) apparmor: Fix tasks not subject to, reloaded policy
    - LP: #1236455

  [ Kamal Mostafa ]

  * SAUCE: (no-up) drm/i915: i915.disable_pch_pwm overrides PCH_PWM_ENABLE
    - LP: #1163720

  [ Manoj Iyer ]

  * SAUCE: Enable earlyprintk via the PL011.
    - LP: #1248233

  [ Paolo Pisati ]

  * [Config] armhf: RTC_DRV_PL031=y
    - LP: #1252242
  * [Config] armhf: CPU_FREQ=y && ARM_HIGHBANK_CPUFREQ=y
    - LP: #1249397

  [ Rob Herring ]

  * [Config] armhf: PSTORE_RAM=y and PSTORE_CONSOLE=y
    - LP: #1248492
  * SAUCE: net: calxedaxgmac: add mac address learning
    - LP: #1248233

  [ Tim Gardner ]

  * [Debian] Re-sign modules after debug objcopy
    - LP: #1253155

  [ Upstream Kernel Changes ]

  * Revert "rt2x00pci: Use PCI MSIs whenever possible"
    - LP: #1257037
  * Revert "epoll: use freezable blocking call"
    - LP: #1257037
  * Revert "select: use freezable blocking call"
    - LP: #1257037
  * Revert "ima: policy for RAMFS"
    - LP: #1257037
  * ARM: tlb: don't perform inner-shareable invalidation for local TLB ops
    - LP: #1239800
  * ARM: 7855/1: Add check for Cortex-A15 errata 798181 ECO
    - LP: #1239800
  * mfd: rtsx: Modify rts5249_optimize_phy
    - LP: #1255297
  * usb: musb: start musb on the udc side, too
    - LP: #1257037
  * usb-storage: add quirk for mandatory READ_CAPACITY_16
    - LP: #1257037
  * USB: support new huawei devices in option.c
    - LP: #1257037
  * USB: quirks.c: add one device that cannot deal with suspension
    - LP: #1257037
  * USB: quirks: add touchscreen that is dazzeled by remote wakeup
    - LP: #1257037
  * USB: serial: ftdi_sio: add id for Z3X Box device
    - LP: #1257037
  * xhci: Don't enable/disable RWE on bus suspend/resume.
    - LP: #1257037
  * cifs: Fix inability to write files >2GB to SMB2/3 shares
    - LP: #1257037
  * x86: Update UV3 hub revision ID
    - LP: #1257037
  * cpufreq: s3c64xx: Rename index to driver_data
    - LP: #1257037
  * cpufreq / intel_pstate: Fix max_perf_pct on resume
    - LP: #1257037
  * bcache: Fixed incorrect order of arguments to bio_alloc_bioset()
    - LP: #1257037
  * HID: wiimote: add LEGO-wiimote VID
    - LP: #1257037
  * cgroup: fix to break the while loop in cgroup_attach_task() correctly
    - LP: #1257037
  * mac80211: correctly close cancelled scans
    - LP: #1257037
  * mac80211: drop spoofed packets in ad-hoc mode
    - LP: #1257037
  * mac80211: use sta_info_get_bss() for nl80211 tx and client probing
    - LP: #1257037
  * mac80211: update sta->last_rx on acked tx frames
    - LP: #1257037
  * mac80211: fix crash if bitrate calculation goes wrong
    - LP: #1257...

Changed in linux (Ubuntu):
status: Confirmed → Fix Released
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