** Changed in: linux (Ubuntu) Assignee: Chris J Arges (arges) => (unassigned)
-- 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/1476244 Title: openvswitch, ppc64el: oops when calling kmem_cache_free from flow_free Status in linux package in Ubuntu: In Progress Bug description: [Impact] Users of openvswitch on ppc64el 4.1+ kernels may run into the following kernel oops: Faulting instruction address: 0xc000000000291d60 Oops: Kernel access of bad area, sig: 11 [#1] SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: veth openvswitch libcrc32c ib_iser rdma_cm iw_cm ib_cm ib_sa ib_mad ib_core ib_addr iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi btrfs xor raid6_pq powernv_rng uio_pdrv_genirq uio autofs4 ses enclosure ipr CPU: 16 PID: 996 Comm: kworker/16:1 Not tainted 4.1.0-1-generic #1~rc2-Ubuntu Workqueue: events od_dbs_timer task: c000000fe49ea400 ti: c000000fe1380000 task.ti: c000000fe1380000 NIP: c000000000291d60 LR: c000000000292254 CTR: c000000000292140 REGS: c000000fe1383170 TRAP: 0300 Not tainted (4.1.0-1-generic) MSR: 9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE> CR: 28028082 XER: 20000000 CFAR: c000000000008468 DAR: 00000000ffffffff DSISR: 42000000 SOFTE: 1 GPR00: c000000000292254 c000000fe13833f0 c0000000014bda00 c000000ff701f800 GPR04: f0000000003fffc0 00000000ffffffff d0000000120cd694 0000000000002fb2 GPR08: 0000000000000000 0000000000000000 0000000000210d00 d0000000120d2520 GPR12: c000000000292140 c00000000fb89000 c0000000000de5f8 000000000000000a GPR16: c000000febbe3828 0000000000000001 0000000000000000 c0000000013d0c80 GPR20: c000000000aa36f8 7fffffffffffffff 0000000000000000 0000000000000001 GPR24: c0000000013c9200 0000000000210d00 00000000ffffffff c000000ff701f800 GPR28: 0000000000000001 0000000000000000 0000000000000000 f0000000003fffc0 NIP [c000000000291d60] __slab_free+0x90/0x470 LR [c000000000292254] kmem_cache_free+0x114/0x2d0 Call Trace: [c000000fe13833f0] [c000000fe1383500] 0xc000000fe1383500 (unreliable) [c000000fe13834f0] [c000000000292254] kmem_cache_free+0x114/0x2d0 [c000000fe1383570] [d0000000120cd694] flow_free+0xa4/0x120 [openvswitch] [c000000fe13835b0] [c000000000136090] rcu_process_callbacks+0x360/0x730 [c000000fe1383660] [c0000000000b824c] __do_softirq+0x19c/0x3b0 [c000000fe1383760] [c0000000000b86d8] irq_exit+0xc8/0x100 [c000000fe1383780] [c00000000003ed78] doorbell_exception+0xa8/0xe0 [c000000fe13837b0] [c000000000003314] h_doorbell_common+0x114/0x180 --- interrupt: e81 at osq_lock+0xb8/0x1f0 LR = mutex_optimistic_spin+0xdc/0x280 [c000000fe1383aa0] [c00000000013e280] add_timer_on+0xc0/0x160 (unreliable) [c000000fe1383ad0] [c000000000116f4c] mutex_optimistic_spin+0xdc/0x280 [c000000fe1383b30] [c000000000a60d04] __mutex_lock_slowpath+0x54/0x1f0 [c000000fe1383bb0] [c000000000a60f18] mutex_lock+0x78/0xa0 [c000000fe1383be0] [c0000000008965bc] od_dbs_timer+0x7c/0x1d0 [c000000fe1383c50] [c0000000000d6434] process_one_work+0x1a4/0x4c0 [c000000fe1383ce0] [c0000000000d68e4] worker_thread+0x194/0x600 [c000000fe1383d80] [c0000000000de700] kthread+0x110/0x130 [c000000fe1383e30] [c0000000000094f4] ret_from_kernel_thread+0x5c/0x68 Instruction dump: 614a0d00 7d484838 2fa80000 409e029c 3f200021 3b800001 63390d00 408200a4 e93b0022 82ff0018 ebdf0010 92e10078 <7fda492a> a1210078 3929ffff 79290420 ---[ end trace bd509c1e05c7f71f ]--- This seems to not happen in VMs running on ppc64el, and doesn't occur on x86_64. I've also tested latest mainline tree and it also occurs. With numa=off this problem doesn't occur. reverting commit 3af229f2071f5b5cb31664be6109561fbe19c861 fixes the issue. [Test Case] # apt-get install openvswitch-switch # ip link add type veth peer name testveth0 # ovs-vsctl add-br integbr To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1476244/+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