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

From: Vlastimil Babka
Date: Tue Jun 16 2020 - 04:02:42 EST


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
>