I think this patch can get this issue fixed on Cosmic: https://github.com/torvalds/linux/commit/43a1b0cb4cd6dbfd3cd9c10da663368394d299d8 (found in this thread https://lkml.org/lkml/2018/12/3/1219)
Test kernel: http://people.canonical.com/~phlin/kernel/lp-1826385-ftrace-hang/ Cosmic KVM and bare-metal passed the ftrace test with this test kernel. The commit that fixed by this patch has already landed in Cosmic for a while, for now I can't tell why this was only gets triggered recently and why this is not failing in the last cycle. (The gcc version in the last cycle is already 8, 4:8.3.0-1ubuntu1.1 from -proposed.) ** Also affects: linux (Ubuntu Cosmic) Importance: Undecided Status: New -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1826385 Title: ftrace in ubuntu_kernel_selftests hang with Cosmic kernel Status in ubuntu-kernel-tests: New Status in linux package in Ubuntu: Confirmed Status in linux source package in Cosmic: New Bug description: This issue is a bit strange. The test has passed with Cosmic 4.18.0-18.19 generic kernel on AMD64 node during our SRU testing process. https://pastebin.ubuntu.com/p/HN2vN6fCXn/ However, Tyler found that this test will hang after: [30] Kretprobe dynamic event with maxactive [PASS] [31] Register/unregister many kprobe events [PASS] And this is 100% reproducible. No relevant output in syslog. This will need further investigation. ProblemType: Bug DistroRelease: Ubuntu 18.10 Package: linux-image-4.18.0-18-generic 4.18.0-18.19 ProcVersionSignature: User Name 4.18.0-18.19-generic 4.18.20 Uname: Linux 4.18.0-18-generic x86_64 AlsaDevices: total 0 crw-rw---- 1 root audio 116, 1 Apr 25 07:16 seq crw-rw---- 1 root audio 116, 33 Apr 25 07:16 timer AplayDevices: Error: [Errno 2] No such file or directory: 'aplay': 'aplay' ApportVersion: 2.20.10-0ubuntu13.2 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord': 'arecord' AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: Date: Thu Apr 25 07:18:51 2019 IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig': 'iwconfig' Lsusb: Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub MachineType: QEMU Standard PC (i440FX + PIIX, 1996) PciMultimedia: ProcFB: 0 cirrusdrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.18.0-18-generic root=UUID=2f68c627-8ab4-40d5-8c06-6563436d0f96 ro RelatedPackageVersions: linux-restricted-modules-4.18.0-18-generic N/A linux-backports-modules-4.18.0-18-generic N/A linux-firmware 1.175.3 RfKill: Error: [Errno 2] No such file or directory: 'rfkill': 'rfkill' SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 04/01/2014 dmi.bios.vendor: SeaBIOS dmi.bios.version: Ubuntu-1.8.2-1ubuntu1 dmi.chassis.type: 1 dmi.chassis.vendor: QEMU dmi.chassis.version: pc-i440fx-xenial dmi.modalias: dmi:bvnSeaBIOS:bvrUbuntu-1.8.2-1ubuntu1:bd04/01/2014:svnQEMU:pnStandardPC(i440FX+PIIX,1996):pvrpc-i440fx-xenial:cvnQEMU:ct1:cvrpc-i440fx-xenial: dmi.product.name: Standard PC (i440FX + PIIX, 1996) dmi.product.version: pc-i440fx-xenial dmi.sys.vendor: QEMU To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-kernel-tests/+bug/1826385/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
