This bug is missing log files that will aid in diagnosing the problem. >From a terminal window please run:
apport-collect 1403459 and then change the status of the bug to 'Confirmed'. If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'. This change has been made by an automated script, maintained by the Ubuntu Kernel Team. ** Changed in: linux (Ubuntu) Status: New => Incomplete ** Tags added: utopic -- 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: Incomplete Status in linux package in Debian: 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 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