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iMX6 Kernel Oops in swapper / ktime_get()

Question asked by kal on Feb 22, 2016
Latest reply on Mar 3, 2016 by jamesbone
Branched to a new discussion

Hi, I am seeing occasional kernel oops due to NULL pointer dereference on one of my boards. It happens about once per day, always seems to be related to ktime_get(), and always appears to be in a "swapper" process. Has anyone seen similar on the iMX6Q?

Unable to handle kernel NULL pointer dereference at virtual address 00000000^M

pgd = 80004000^M

[00000000] *pgd=00000000^M

Internal error: Oops: 17 [#1] PREEMPT SMP ARM^M

Modules linked in:^M

CPU: 3 PID: 0 Comm: swapper/3 Not tainted 3.14.28-1.0.0_ga+g91cf351 #1^M

task: a8083c00 ti: a80aa000 task.ti: a80aa000^M

PC is at ktime_get+0x4c/0x114^M

LR is at cpuidle_enter_state+0x4c/0xe4^M

pc : [<80073624>]    lr : [<804fe670>]    psr: 60070093^M

sp : a80abf58  ip : 00000017  fp : 00000000^M

r10: a80abf98  r9 : 000b6c7c  r8 : 67d8c054^M

r7 : 00000000  r6 : 00000000  r5 : 80eda200  r4 : a9362704^M

r3 : 00000000  r2 : 56c9e9f3  r1 : 80e407c8  r0 : a8011a00^M

Flags: nZCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel^M

Control: 10c53c7d  Table: 13b9804a  DAC: 00000015^M

Process swapper/3 (pid: 0, stack limit = 0xa80aa238)^M

Stack: (0xa80abf58 to 0xa80ac000)^M

bf40:                                                       56c9e9f3 00000000^M

bf60: ffffffff 00000000 d4f2f610 00158fb9 ab73d340 80e407c8 80e407c8 ab73d0d0^M

bf80: 00000000 67d8c054 000003f3 a80aa000 00000000 804fe670 67d8c054 000003f3^M

bfa0: 80e46254 ab73d0d0 80e3a574 ab73d0d0 00000000 00000000 00000000 80ef17a4^M

bfc0: 80e407c8 804fe7bc 00000000 a80aa000 80e3a574 8075938c a80aa030 80e943fd^M

bfe0: 80e943fd 8000f17c 00000000 80068234 80e9491c 10008664 56f7c91b 356f332a^M

[<80073624>] (ktime_get) from [<804fe670>] (cpuidle_enter_state+0x4c/0xe4)^M

[<804fe670>] (cpuidle_enter_state) from [<804fe7bc>] (cpuidle_idle_call+0xb4/0x14c)^M

[<804fe7bc>] (cpuidle_idle_call) from [<8000f17c>] (arch_cpu_idle+0x8/0x44)^M

[<8000f17c>] (arch_cpu_idle) from [<80068234>] (cpu_startup_entry+0x100/0x14c)^M

[<80068234>] (cpu_startup_entry) from [<10008664>] (0x10008664)^M

Code: e1c523d8 e5954054 e1a00006 e1cd20f0 (e5963000) ^M

bad: scheduling from the idle thread!^M

CPU: 3 PID: 0 Comm: swapper/3 Not tainted 3.14.28-1.0.0_ga+g91cf351 #1^M

[<800156f0>] (unwind_backtrace) from [<800117d4>] (show_stack+0x10/0x14)^M


Note that this is using the Fido branch of Yocto.


Many thanks