Hi Jospeh, I installed the kernel from http://kernel.ubuntu.com/~jsalisbury/lp1403459/ and can confirm that this kernel version fixes the bug.
-- 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/1403459 Title: kernel bug when hotplugging a CPU Status in linux package in Ubuntu: Confirmed Status in linux package in Debian: Confirmed Status in linux package in Fedora: Unknown Status in linux package in openSUSE: Fix Released Bug description: When I hot-plug a CPU to an Ubuntu 14.10 VM running on KVM, I get following kernel bug. Ubuntu 14.04 is not affected by this bug. # uname -a Linux ubuntu 3.16.0-28-generic #38-Ubuntu SMP Fri Dec 12 17:37:40 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux # dmesg [ 109.469094] CPU1 has been hot-added [ 109.477005] SMP alternatives: switching to SMP code [ 109.490583] x86: Booting SMP configuration: [ 109.490586] smpboot: Booting Node 0 Processor 1 APIC 0x1 [ 109.476344] kvm-clock: cpu 1, msr 0:3ffe6041, secondary cpu clock [ 109.586704] kvm: enabling virtualization on CPU1 [ 109.596330] KVM setup async PF for cpu 1 [ 109.596330] kvm-stealtime: cpu 1, msr 3de2d100 [ 109.596645] microcode: CPU1: patch_level=0x01000065 [ 109.596910] Will online and init hotplugged CPU: 1 [ 109.598469] kobject '(null)' (ffff88003de3b5d8): tried to add an uninitialized object, something is seriously wrong. [ 109.599255] CPU: 0 PID: 1424 Comm: systemd-udevd Not tainted 3.16.0-28-generic #38-Ubuntu [ 109.599257] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 109.599259] ffff880036465250 ffff88003af77c88 ffffffff81781eaa ffff88003de3b5d8 [ 109.599263] ffff88003af77cf8 ffffffff8139e896 ffff880000000020 ffff88003af77d08 [ 109.599266] ffff88003af77cb0 ffff88003af77cc8 ffffffff8137967b 0000000000000001 [ 109.599269] Call Trace: [ 109.599276] [<ffffffff81781eaa>] dump_stack+0x45/0x56 [ 109.599280] [<ffffffff8139e896>] kobject_add+0xa6/0xb0 [ 109.599283] [<ffffffff8137967b>] ? get_first_sibling+0x2b/0x40 [ 109.599287] [<ffffffff8139d08d>] ? ida_get_new_above+0x1dd/0x210 [ 109.599291] [<ffffffff81378b66>] blk_mq_register_hctx+0xa6/0xc0 [ 109.599293] [<ffffffff813794c1>] blk_mq_sysfs_register+0x41/0x60 [ 109.599297] [<ffffffff81376fc2>] blk_mq_queue_reinit_notify+0x72/0xb0 [ 109.599300] [<ffffffff8109972d>] notifier_call_chain+0x4d/0x70 [ 109.599303] [<ffffffff8109983e>] __raw_notifier_call_chain+0xe/0x10 [ 109.599306] [<ffffffff81070133>] cpu_notify+0x23/0x50 [ 109.599309] [<ffffffff81070348>] _cpu_up+0x168/0x180 [ 109.599312] [<ffffffff810703ea>] cpu_up+0x8a/0xb0 [ 109.599315] [<ffffffff81778ee0>] cpu_subsys_online+0x40/0xa0 [ 109.599319] [<ffffffff814cf225>] device_online+0x65/0x90 [ 109.599322] [<ffffffff814cf2cd>] online_store+0x7d/0x90 [ 109.599325] [<ffffffff814cc658>] dev_attr_store+0x18/0x30 [ 109.599328] [<ffffffff8125950a>] sysfs_kf_write+0x3a/0x50 [ 109.599331] [<ffffffff812586ae>] kernfs_fop_write+0xee/0x180 [ 109.599335] [<ffffffff811e10b7>] vfs_write+0xb7/0x1f0 [ 109.599338] [<ffffffff811e1c66>] SyS_write+0x46/0xb0 [ 109.599342] [<ffffffff81789eed>] system_call_fastpath+0x1a/0x1f I initially reported this bug in openSUSE and it was fixed in the Linus tree: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=06a41a9 --- AlsaDevices: Error: command ['ls', '-l', '/dev/snd/'] failed with exit code 2: ls: cannot access /dev/snd/: No such file or directory AplayDevices: Error: [Errno 2] No such file or directory ApportVersion: 2.14.7-0ubuntu8 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory CRDA: Error: [Errno 2] No such file or directory DistroRelease: Ubuntu 14.10 IwConfig: eth0 no wireless extensions. lo no wireless extensions. Lsusb: Bus 001 Device 002: ID 0627:0001 Adomax Technology Co., Ltd Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub MachineType: Bochs Bochs Package: linux (not installed) PciMultimedia: ProcFB: 0 EFI VGA ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.16.0-28-generic root=UUID=6c1dd17e-4ffe-45f6-a99d-6b2530505d72 ro consoleblank=0 ProcVersionSignature: Ubuntu 3.16.0-28.38-generic 3.16.7-ckt1 RelatedPackageVersions: linux-restricted-modules-3.16.0-28-generic N/A linux-backports-modules-3.16.0-28-generic N/A linux-firmware 1.138 RfKill: Error: [Errno 2] No such file or directory Tags: utopic utopic Uname: Linux 3.16.0-28-generic x86_64 UnreportableReason: The report belongs to a package that is not installed. UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: _MarkForUpload: True dmi.bios.date: 01/01/2011 dmi.bios.vendor: Bochs dmi.bios.version: Bochs dmi.chassis.type: 1 dmi.chassis.vendor: Bochs dmi.modalias: dmi:bvnBochs:bvrBochs:bd01/01/2011:svnBochs:pnBochs:pvr:cvnBochs:ct1:cvr: dmi.product.name: Bochs dmi.sys.vendor: Bochs To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1403459/+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
