It resolved the bug. Tested successfully on Wily with 4.2.0-10-generic #12~lp1440103 test kernel.
These are the traces in dmesg in the crash logs: [ 187.204774] CPU: 3 PID: 946 Comm: bash Not tainted 4.2.0-10-generic #12~lp1440103 [ 187.204774] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS 090006 05/23/2012 [ 187.204774] task: ffff8800f077cb00 ti: ffff8800f23ac000 task.ti: ffff8800f23ac000 [ 187.204774] RIP: 0010:[<ffffffff814a1786>] [ 187.204774] [<ffffffff814a1786>] sysrq_handle_crash+0x16/0x20 [ 187.204774] RSP: 0018:ffff8800f23afe28 EFLAGS: 00010296 [ 187.204774] RAX: 000000000000000f RBX: 0000000000000063 RCX: 000000000000000f [ 187.204774] RDX: ffff8801026d12f8 RSI: ffff8801026cea58 RDI: 0000000000000063 [ 187.204774] RBP: ffff8800f23afe28 R08: 00000000000000c2 R09: 0000000000000002 [ 187.204774] R10: 0000000000000260 R11: 0000000000000002 R12: 0000000000000004 [ 187.204774] R13: 0000000000000000 R14: ffffffff81cc2560 R15: 0000000000000000 [ 187.204774] FS: 00007f385dfc0700(0000) GS:ffff8801026c0000(0000) knlGS:0000000000000000 [ 187.204774] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 187.204774] CR2: 0000000000000000 CR3: 00000000f1111000 CR4: 00000000000006e0 [ 187.204774] Stack: [ 187.204774] ffff8800f23afe58 ffffffff814a1f86 0000000000000002 fffffffffffffffb [ 187.204774] 0000000000980408 0000000000000002 ffff8800f23afe78 ffffffff814a23e3 [ 187.204774] 0000000000000002 ffff8800edeec180 ffff8800f23afe98 ffffffff81252278 [ 187.204774] Call Trace: [ 187.204774] [<ffffffff814a1f86>] __handle_sysrq+0xf6/0x150 [ 187.204774] [<ffffffff814a23e3>] write_sysrq_trigger+0x33/0x40 [ 187.204774] [<ffffffff81252278>] proc_reg_write+0x48/0x70 [ 187.204774] [<ffffffff811eb598>] __vfs_write+0x18/0x40 [ 187.204774] [<ffffffff811ebbd9>] vfs_write+0xa9/0x190 [ 187.204774] [<ffffffff811ec946>] SyS_write+0x46/0xa0 [ 187.204774] [<ffffffff81208f0f>] ? __close_fd+0x8f/0xb0 [ 187.204774] [<ffffffff817b8132>] entry_SYSCALL_64_fastpath+0x16/0x75 [ 187.204774] Code: 45 39 7d 34 75 e5 4c 89 ef e8 17 f8 ff ff eb db 0f 1f 44 00 00 0f 1f 44 00 00 55 c7 05 28 3c a6 00 01 00 00 00 48 89 e5 0f ae f8 <c6> 04 25 00 00 00 00 01 5d c3 0f 1f 44 00 00 55 31 c0 48 89 e5 [ 187.204774] RIP [<ffffffff814a1786>] sysrq_handle_crash+0x16/0x20 [ 187.204774] RSP <ffff8800f23afe28> [ 187.204774] CR2: 0000000000000000 -- 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/1440103 Title: [Hyper-V] Kernel panic not functional on Vivid Status in linux package in Ubuntu: In Progress Status in linux source package in Vivid: In Progress Status in linux source package in Wily: In Progress Bug description: Issue description: Triggering a kernel panic will not produce a crash dump file. Steps to Reproduce: 1. install kdump related packages. 2. verify crashmem value - defaults to 384M-:129M 3. verify that the system is ready for crash: # cat /sys/kernel/kexec_crash_loaded 1 4. trigger kernel panic with # echo c | sudo tee /proc/sysrq-trigger 5. The system will freeze and no kernel dump will be generated, system is not rebooted automatically as configured in kdump-tools config. Versions details: Windows Server Host Edition: Microsoft Windows Server 2012 R2 Datacenter build 9600 Distribution name and release: Ubuntu Vivid Vervet Kernel version: Linux ubuntu31 3.19.0-11-generic #11lp14233432v201504021617 SMP Repro output with VM settings as follows: 2GB RAM, 1vCPU, crashmem: 384M:128M OR 384M:128M [ 149.328829] SysRq : Trigger a crash [ 149.342418] BUG: unable to handle kernel NULL pointer dereference at (null) [ 149.346369] IP: [<ffffffff814ae776>] sysrq_handle_crash+0x16/0x20 [ 149.346369] PGD 367a3067 PUD 7bdf0067 PMD 0 [ 149.346369] Oops: 0002 [#1] SMP [ 149.346369] Modules linked in: joydev hid_generic hid_hyperv serio_raw hid 8250_fintek hyperv_keyboard hv_balloon hyp erv_fb i2c_piix4 mac_hid autofs4 hv_netvsc hv_utils hv_storvsc psmouse floppy pata_acpi hv_vmbus [ 149.346369] CPU: 0 PID: 1379 Comm: tee Not tainted 3.19.0-11-generic #11lp14233432v201504021617 [ 149.346369] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS 090006 05/23/2012 [ 149.346369] task: ffff88007a7d3ae0 ti: ffff88007be7c000 task.ti: ffff88007be7c000 [ 149.346369] RIP: 0010:[<ffffffff814ae776>] [<ffffffff814ae776>] sysrq_handle_crash+0x16/0x20 [ 149.346369] RSP: 0018:ffff88007be7fe68 EFLAGS: 00010292 [ 149.346369] RAX: 000000000000000f RBX: 0000000000000063 RCX: 000000000000000f [ 149.346369] RDX: ffff88007ce0fd78 RSI: ffff88007ce0e498 RDI: 0000000000000063 [ 149.346369] RBP: ffff88007be7fe68 R08: 0000000000000002 R09: 0000000000000275 [ 149.346369] R10: 0000000000000092 R11: 0000000000000275 R12: 0000000000000004 [ 149.346369] R13: 0000000000000000 R14: ffffffff81cb38e0 R15: 0000000000000008 [ 149.346369] FS: 00007f0a2e22a700(0000) GS:ffff88007ce00000(0000) knlGS:0000000000000000 [ 149.346369] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 149.346369] CR2: 0000000000000000 CR3: 0000000036047000 CR4: 00000000000006f0 [ 149.346369] Stack: [ 149.346369] ffff88007be7fe98 ffffffff814aef96 0000000000000002 fffffffffffffffb [ 149.346369] 00007ffc64e934b0 0000000000000002 ffff88007be7feb8 ffffffff814af443 [ 149.346369] 00007ffc64e934b0 ffff8800364f15c0 ffff88007be7fed8 ffffffff8125ad98 [ 149.346369] Call Trace: [ 149.346369] [<ffffffff814aef96>] __handle_sysrq+0x106/0x170 [ 149.346369] [<ffffffff814af443>] write_sysrq_trigger+0x33/0x40 [ 149.346369] [<ffffffff8125ad98>] proc_reg_write+0x48/0x70 [ 149.346369] [<ffffffff811f33d7>] vfs_write+0xb7/0x1f0 [ 149.346369] [<ffffffff811f3ece>] ? vfs_read+0x11e/0x140 [ 149.346369] [<ffffffff811f3fe6>] SyS_write+0x46/0xb0 [ 149.346369] [<ffffffff817c924d>] system_call_fastpath+0x16/0x1b [ 149.346369] Code: ef e8 df f7 ff ff eb d8 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 66 66 66 66 90 55 c7 05 34 42 a3 00 01 00 00 00 48 89 e5 0f ae f8 <c6> 04 25 00 00 00 00 01 5d c3 66 66 66 66 90 55 31 c0 48 89 e5 [ 149.346369] RIP [<ffffffff814ae776>] sysrq_handle_crash+0x16/0x20 [ 149.346369] RSP <ffff88007be7fe68> [ 149.346369] CR2: 0000000000000000 [ 0.000000] Initializing cgroup subsys cpuset [ 0.000000] Initializing cgroup subsys cpu [ 0.000000] Initializing cgroup subsys cpuacct [ 0.000000] Linux version 3.19.0-11-generic (apw@gloin) (gcc version 4.9.2 (Ubuntu 4.9.2-10ubuntu12) ) #11lp14233432v 201504021617 SMP Thu Apr 2 15:15:51 UTC 2015 (Ubuntu 3.19.0-11.11lp14233432v201504021617-generic 3.19.3) [ 0.000000] Command line: BOOT_IMAGE=/vmlinuz-3.19.0-11-generic root=/dev/mapper/ubuntu31--vg-root ro console=tty0 co nsole=ttyS1 irqpoll maxcpus=1 nousb systemd.unit=kdump-tools.service elfcorehdr=867700K To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1440103/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp

