** Description changed: + == Justification == + Running the ftrace in ubuntu_kernel_selftests repetitively against x86 Cosmic kernel will cause system hang. + + This hang is caused by one of the sub-test: kprobe/multiple_kprobes + + Upstream discussion could be found here: + https://lkml.org/lkml/2018/12/3/1219 + + == Fix == + 43a1b0cb4 (kprobes/x86: Fix instruction patching corruption when copying more than one RIP-relative instruction) + + This patch is already in D. + For B/C, they all have this ill-commit 63fef14 and this patch can be cherry-picked, however this is related to GCC-8 and our 4.15 kernel was build with GCC-7 on Bionic, I will skip it for now. + + For X, the ill-commit 63fef14 does not exist. + + == Test == + Test kernel for Cosmic: + http://people.canonical.com/~phlin/kernel/lp-1826385-ftrace-hang/ + + Patch tested with a bare-metal and a KVM node, both of them can pass the + beating repetitively. + + == Regression Potential == + Upstream fix limited to x86 architecture, and specific for kprobe. + + + == Original Bug Report == 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 + 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 + 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
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1826385 Title: ftrace in ubuntu_kernel_selftests hang with Cosmic kernel To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-kernel-tests/+bug/1826385/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
