Re: [kernel/watchdog.c] f117955a22: kmsg.Failed_to_set_sysctl_parameter'kernel.softlockup_panic=#':parameter_not_found

[Vlastimil Babka]

On 6/16/20 9:38 AM, kernel test robot wrote:
> Greeting,
> 
> FYI, we noticed the following commit (built with gcc-9):
> 
> commit: f117955a2255721a6a0e9cecf6cad3a6eb43cbc3 ("kernel/watchdog.c: convert {soft/hard}lockup boot parameters to sysctl aliases")
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
> 
> in testcase: boot
> 
> on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
> 
> caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):
> 
> 
> 
> If you fix the issue, kindly add following tag
> Reported-by: kernel test robot <rong.a.chen@xxxxxxxxx>
> 
> 
> 
> [    5.306502] netconsole: network logging started
> [    5.793973] input: ImExPS/2 Generic Explorer Mouse as /devices/platform/i8042/serio1/input/input3
> [    5.804702] e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
> [    5.828198] Sending DHCP requests ., OK
> [    5.829815] IP-Config: Got DHCP answer from 10.0.2.2, my address is 10.0.2.15
> [    5.831412] IP-Config: Complete:
> [    5.832501]      device=eth0, hwaddr=52:54:00:12:34:56, ipaddr=10.0.2.15, mask=255.255.255.0, gw=10.0.2.2
> [    5.835246]      host=vm-snb-ssd-19, domain=, nis-domain=(none)
> [    5.836806]      bootserver=10.0.2.2, rootserver=10.0.2.2, rootpath=
> [    5.836808]      nameserver0=10.0.2.3
> [    5.839613] ALSA device list:
> [    5.857103]   No soundcards found.
> [    5.860706] Freeing unused kernel image (initmem) memory: 1540K
> [    5.868210] Write protecting the kernel read-only data: 20480k
> [    5.870913] Freeing unused kernel image (text/rodata gap) memory: 2044K
> [    5.872636] Freeing unused kernel image (rodata/data gap) memory: 68K
> [    5.874149] rodata_test: all tests were successful
> [    5.875553] Failed to set sysctl parameter 'kernel.softlockup_panic=1': parameter not found

In case the line above is the reason for this report, then it's because .config has:

# CONFIG_SOFTLOCKUP_DETECTOR is not set

While previously the softlockup_panic=1 parameter would be just silently ignored
in that case. I don't think it's wrong to report it, though.

> [    5.896259] Run /init as init process
> [    5.897454]   with arguments:
> [    5.898493]     /init
> [    5.899418]   with environment:
> [    5.900468]     HOME=/
> [    5.901346]     TERM=linux
> [    5.902311]     user=lkp
> [    5.903266]     job=/lkp/jobs/scheduled/vm-snb-ssd-19/boot-1-debian-i386-20191205.cgz-f117955a2255721a6a0e9cecf6cad3a6eb43cbc3-20200615-43661-1fqppwn-3.yaml
> [    5.906363]     ARCH=x86_64
> [    5.907358]     kconfig=x86_64-kexec
> [    5.908495]     branch=linus/master
> [    5.909564]     commit=f117955a2255721a6a0e9cecf6cad3a6eb43cbc3
> [    5.910982]     BOOT_IMAGE=/pkg/linux/x86_64-kexec/gcc-9/f117955a2255721a6a0e9cecf6cad3a6eb43cbc3/vmlinuz-5.7.0-12506-gf117955a22557
> [    5.913735]     max_uptime=600
> [    5.914651]     RESULT_ROOT=/result/boot/1/vm-snb-ssd/debian-i386-20191205.cgz/x86_64-kexec/gcc-9/f117955a2255721a6a0e9cecf6cad3a6eb43cbc3/3
> [    5.917437]     LKP_SERVER=inn
> [    5.918425]     selinux=0
> [    5.919398]     softlockup_panic=1
> [    5.920495]     nmi_watchdog=panic
> [    5.925722]     prompt_ramdisk=0
> [    5.926843]     vga=normal
> [    5.927739]     watchdog_thresh=60
> [    5.934222] systemd[1]: RTC configured in localtime, applying delta of 0 minutes to system time.
> [    5.937449] systemd[1]: Failed to insert module 'autofs4': No such file or directory
> [    5.941850] random: systemd: uninitialized urandom read (16 bytes read)
> [    5.947176] random: systemd: uninitialized urandom read (16 bytes read)
> 
> 
> To reproduce:
> 
>         # build kernel
> 	cd linux
> 	cp config-5.7.0-12506-gf117955a22557 .config
> 	make HOSTCC=gcc-9 CC=gcc-9 ARCH=x86_64 olddefconfig prepare modules_prepare bzImage
> 
>         git clone https://github.com/intel/lkp-tests.git
>         cd lkp-tests
>         bin/lkp qemu -k <bzImage> job-script # job-script is attached in this email
> 
> 
> 
> Thanks,
> Rong Chen
>