[rt-devel:linux-7.0.y-rt-rebase] 55eabced1d: BUG:kernel_reboot-without-warning_in_test_stage

kernel test robot <[email protected]> Fri, 27 Feb 2026 15:57:19 +0800
Newsgroups dev.linux.lists.oe-lkp,org.kernel.vger.linux-serial
Message-ID <[email protected]>

Hello,


patch "serial: 8250: Switch to nbcon console" was reverted by

  f79b163c42314 Revert "serial: 8250: Switch to nbcon console"

based on our previous old report
"[linux-next:master] [serial]  b63e6f60ea: BUG:soft_lockup-CPU##stuck_for#s![modprobe:#]"
in
https://lore.kernel.org/all/[email protected]/

there are some discussions which seems think the commit is not the real root
cause of the issue.

this commit 55eabced1d reapplies "serial: 8250: Switch to nbcon console", then
we notice a new "kernel_reboot-without-warning_in_test_stage" issue in a boot
test with randconfig. however, unfortunately, we cannot capture further useful
information in dmesg.

so maybe this report cannot supply enough useful information, just FYI what
we observed in our tests.


below is full report.


kernel test robot noticed "BUG:kernel_reboot-without-warning_in_test_stage" on:

commit: 55eabced1d566d2815cc215272ece998c8f2e93f ("Reapply "serial: 8250: Switch to nbcon console"")
https://git.kernel.org/cgit/linux/kernel/git/rt/linux-rt-devel.git linux-7.0.y-rt-rebase

in testcase: boot

config: x86_64-randconfig-001-20260225
compiler: gcc-13
test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 32G

(please refer to attached dmesg/kmsg for entire log/backtrace)


+-------------------------------------------------+----------+------------+
|                                                 | v7.0-rc1 | 55eabced1d |
+-------------------------------------------------+----------+------------+
| boot_successes                                  | 40       | 0          |
| boot_failures                                   | 0        | 6          |
| BUG:kernel_reboot-without-warning_in_test_stage | 0        | 6          |
+-------------------------------------------------+----------+------------+

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email protected]>
| Closes: https://lore.kernel.org/oe-lkp/[email protected]



[   16.023891][  T126] sleep started
[   16.023940][  T126]
[   17.102254][  T126] /usr/bin/wget -q --timeout=3600 --tries=1 --local-encoding=UTF-8 http://internal-lkp-server:80/~lkp/cgi-bin/lkp-jobfile-append-var?job_file=/lkp/jobs/scheduled/vm-meta-288/boot-1-quantal-x86_64-core-20190426.cgz-x86_64-randconfig-001-20260225-55eabced1d56-20260226-27605-1wm64jc-2.yaml&job_state=post_run -O /dev/null
[   17.106752][  T126]
mkdir: cannot create directory `/var/lock/lkp-bootstrap.lock': File exists
[   19.145988][  T126] kill 428 vmstat -n 1
[   19.146032][  T126]
[   19.189830][  T126] kill 419 cat /proc/kmsg
[   19.189873][  T126]
[   19.253688][  T126] kill 447 /bin/sh /lkp/lkp/src/programs/watchdog/monitor
[   19.258684][  T126]
[   19.277825][  T126] wait for background processes: 439
[   19.277867][  T126]
[   19.279442][  T126] monitor
[   19.279463][  T126]
[   24.067178][  T126] /usr/bin/wget -q --timeout=3600 --tries=1 --local-encoding=UTF-8 http://internal-lkp-server:80/~lkp/cgi-bin/lkp-jobfile-append-var?job_file=/lkp/jobs/scheduled/vm-meta-288/boot-1-quantal-x86_64-core-20190426.cgz-x86_64-randconfig-001-20260225-55eabced1d56-20260226-27605-1wm64jc-2.yaml&loadavg=0.94%200.22%200.07%201/102%20625&start_time=1772044359&end_time=1772044361&version=/lkp/lkp/.src-20260226-000921:3d999d51ba0e-dirty:bc8736f22ca0& -O /dev/null
[   24.067231][  T126]
[   25.032907][  T126] /usr/bin/wget -q --timeout=3600 --tries=1 --local-encoding=UTF-8 http://internal-lkp-server:80/~lkp/cgi-bin/lkp-jobfile-append-var?job_file=/lkp/jobs/scheduled/vm-meta-288/boot-1-quantal-x86_64-core-20190426.cgz-x86_64-randconfig-001-20260225-55eabced1d56-20260226-27605-1wm64jc-2.yaml&job_state=finished -O /dev/null
[   25.035121][  T126]
[   25.272417][    T1] init: tty4 main process (515) terminated with status 1
[   25.273235][    T1] init: tty4 main process ended, respawning
[   25.304364][    T1] init: tty5 main process (518) terminated with status 1
[   25.305147][    T1] init: tty5 main process ended, respawning
[   25.320550][    T1] init: tty2 main process (519) terminated with status 1
[   25.321322][    T1] init: tty2 main process ended, respawning
[   25.340485][    T1] init: tty3 main process (522) terminated with status 1
[   25.341245][    T1] init: tty3 main process ended, respawning
[   25.368534][    T1] init: tty6 main process (523) terminated with status 1
[   25.369377][    T1] init: tty6 main process ended, respawning
LKP: ttyS0: 103: LKP: tbox cant kexec and rebooting forcely
[   26.117689][  T126] LKP: stdout: 103: LKP: tbox cant kexec and rebooting forcely
[   26.117719][  T126]
[   26.234198][  T126] /usr/bin/wget -q --timeout=3600 --tries=1 --local-encoding=UTF-8 http://internal-lkp-server:80/~lkp/cgi-bin/lkp-wtmp?tbox_name=vm-snb&tbox_state=rebooting_cant_kexec&job_file=/lkp/jobs/scheduled/vm-meta-288/boot-1-quantal-x86_64-core-20190426.cgz-x86_64-randconfig-001-20260225-55eabced1d56-20260226-27605-1wm64jc-2.yaml -O /dev/null
[   26.238678][  T126]
BUG: kernel reboot-without-warning in test stage



The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20260227/[email protected]



-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki