Warnings are reported by preempt-rt kernel when dumping vmcore
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
StarlingX |
Fix Released
|
Low
|
Jiping Ma |
Bug Description
Brief Description
**The preempt-rt kernel reports warnings when dumping vmcore files due to the use of kernel command line arguments such as nohz_full=, isolcpus=, rcu_nocbs= with the kexec/kdump kernel.
Severity
Minor: vmcore dump appears to work, but there are warnings which may cause confusion.
Steps to Reproduce
I was able to reproduce this issue with the 5.10.74 preempt-rt kernel as follows:
[ 9.724046] io scheduler kyber registered
Startin[ 9.724064] io scheduler bfq registered
g udev Kernel De[ 9.735536] ------------[ cut here ]------------
vice Manager...[ 9.735537] WARNING: CPU: 0 PID: 0 at kernel/
[ 9.735543] Modules linked in:
[ 9.735545] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.10.74-
[ 9.735547] Hardware name: Intel Corporation S2600WT2R/
[ 9.735548] RIP: 0010:tick_
[ 9.735550] Code: 01 00 75 26 89 15 36 74 6f 01 48 8b 05 2b 87 d5 01 48 89 f1 48 29 c1 48 3b 0d 5e 85 d5 01 7c cb 48 89 f7 e8 64 fe ff ff eb c1 <0f> 0b eb d6 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00
[ 9.735552] RSP: 0000:ffffc90000
[ 9.735553] RAX: 00000000ffffffff RBX: ffff888078c1ad00 RCX: 0000000000000018
[ 9.735554] RDX: 0000000000000000 RSI: 0000000243e95b9b RDI: ffff888078c1ad00
[ 9.735555] RBP: ffffffff82603e08 R08: 0000000000000000 R09: 0000000000ed744d
[ 9.735556] R10: 0000ecd267612d86 R11: 0000000000000000 R12: 0000000243e95b9b
[ 9.735557] R13: ffffffff81160f30 R14: 000000000000000f R15: ffff888078c1a540
[ 9.735558] FS: 000000000000000
[ 9.735559] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9.735560] CR2: 0000000000000000 CR3: 0000000077610001 CR4: 00000000003706b0
[ 9.735561] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9.735562] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9.735563] Call Trace:
[ 9.735564] <IRQ>
[ 9.735566] tick_sched_
[ 9.735568] __hrtimer_
[ 9.735572] hrtimer_
[ 9.735574] __sysvec_
[ 9.735578] asm_call_
[ 9.735581] </IRQ>
[ 9.735582] sysvec_
[ 9.735584] asm_sysvec_
[ 9.735586] RIP: 0010:mwait_
[ 9.735588] Code: 0f 01 c8 48 8b 10 83 e2 08 75 21 48 8b 00 a9 00 00 08 00 75 17 e9 07 00 00 00 0f 00 2d 3e 8a 5f 00 31 c0 48 89 c1 fb 0f 01 c9 <eb> 01 fb 65 48 8b 04 25 80 6d 01 00 3e 80 60 02 df c3 0f ae f0 0f
[ 9.735590] RSP: 0000:ffffffff82
[ 9.735591] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[ 9.735592] RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff82618940
[ 9.735592] RBP: ffffffff82858140 R08: 0000000000000000 R09: 0000000000026b40
[ 9.735593] R10: 0000ecd26673cfca R11: 00000000fa83b2da R12: 0000000000000000
[ 9.735594] R13: 0000000000000000 R14: ffffffffffffffff R15: ffffffff82618940
[ 9.735595] default_
[ 9.735598] do_idle+0x23b/0x2f0
[ 9.735600] cpu_startup_
[ 9.735601] start_kernel+
[ 9.735605] secondary_
[ 9.735609] ---[ end trace 0000000000000001 ]---
First, log on to the serial console of the target, and log the serial console output using script and/or another logging tool.
Then run the following command on the target to trigger a kernel NULL pointer dereference (i.e., a controlled crash):
echo c | sudo tee /proc/sysrq-trigger
Expected Behavior
The kdump kernel should not report warnings when dumping the crashed kernel's vmcore.
Actual Behavior
The following warnings are emitted by the kdump kernel:
Reproducibility
100% reproducible
System Configuration
Branch/Pull Time/Commit
Unknown
Last Pass
Unknown; I can confirm with a 3.10 kernel as well if needed.
Timestamp/Logs
Please see above.
Alarms
None.
Test Activity
Developer Testing
Workaround
None.
Changed in starlingx: | |
assignee: | nobody → Jiping Ma (jma11) |
Changed in starlingx: | |
importance: | Undecided → Low |
tags: | added: stx.8.0 stx.distro.other |
Fix proposed to branch: master /review. opendev. org/c/starlingx /integ/ +/865627
Review: https:/