Hi I've got these two stacktraces with the kernel 4.9-rc3. The strange thing is that the kernel doesn't say what kind of problem happened - just a register dump and stack trace.
It happened on virtual machine guest running in qemu-kvm. Mikulas [ 166.917189] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.0-rc3+ #1 [ 166.917194] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 166.917199] task: ffffffff8160c4c0 task.stack: ffffffff81600000 [ 166.917202] RIP: 0010:[<ffffffff813157e2>] [<ffffffff813157e2>] native_safe_halt+0x2/0x10 [ 166.917399] RSP: 0018:ffffffff81603f38 EFLAGS: 00000246 [ 166.917402] RAX: 0000000000080000 RBX: 0000000000000000 RCX: 0100000000000000 [ 166.917405] RDX: 0140000000000000 RSI: 0100000000000000 RDI: 0000000000000046 [ 166.917408] RBP: ffffffff8160c4c0 R08: 0000000000000000 R09: 0000000000000000 [ 166.917410] R10: 0000000000000000 R11: 000000000000d400 R12: ffffffff81650ab8 [ 166.917412] R13: ffffffff8160c4c0 R14: ffffffff8160c4c0 R15: ffffffff81603fb0 [ 166.917433] FS: 0000000000000000(0000) GS:ffff88011fc00000(0000) knlGS:0000000000000000 [ 166.917435] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 166.917438] CR2: 00000000017d9c0c CR3: 000000011a34c000 CR4: 00000000000006b0 [ 166.917454] Stack: [ 166.917457] ffffffff81315765 ffffffff81079bec 000000971fffa740 ffffffffffffffff [ 166.917464] ffff88011fffa740 ffffffff816d8920 ffffffff816e00a0 ffffffff81719000 [ 166.917470] ffffffff8166edc3 ffffffff816e00a0 0000000000000020 ffffffff8166e120 [ 166.917475] Call Trace: [ 166.917512] [<ffffffff81315765>] ? default_idle+0x5/0x10 [ 166.917619] [<ffffffff81079bec>] ? cpu_startup_entry+0xac/0x150 [ 166.917631] [<ffffffff8166edc3>] ? start_kernel+0x385/0x38d [ 166.917636] [<ffffffff8166e120>] ? early_idt_handler_array+0x120/0x120 [ 166.917642] [<ffffffff8166e375>] ? x86_64_start_kernel+0xea/0xf9 [ 166.917644] Code: 04 25 c0 c2 00 00 f0 80 60 02 df c3 0f ae f0 0f ae 38 0f ae f0 eb c8 fb 66 66 90 66 66 90 eb dd 66 0f 1f 84 00 00 00 00 00 fb f4 <c3> 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 f4 c3 90 90 90 90 90 [ 168.503352] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.0-rc3+ #1 [ 168.503357] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 168.503362] task: ffffffff8160c4c0 task.stack: ffffffff81600000 [ 168.503365] RIP: 0010:[<ffffffff813157e2>] [<ffffffff813157e2>] native_safe_halt+0x2/0x10 [ 168.503383] RSP: 0018:ffffffff81603f38 EFLAGS: 00000246 [ 168.503387] RAX: 0000000000080000 RBX: 0000000000000000 RCX: 0100000000000000 [ 168.503390] RDX: 0140000000000000 RSI: 0100000000000000 RDI: 0000000000000046 [ 168.503392] RBP: ffffffff8160c4c0 R08: 0000000000000000 R09: 0000000000000000 [ 168.503395] R10: 0000000000000000 R11: 0000000000010400 R12: ffffffff81650ab8 [ 168.503397] R13: ffffffff8160c4c0 R14: ffffffff8160c4c0 R15: ffffffff81603fb0 [ 168.503416] FS: 0000000000000000(0000) GS:ffff88011fc00000(0000) knlGS:0000000000000000 [ 168.503419] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 168.503422] CR2: 00000000017d9c0c CR3: 000000011a34c000 CR4: 00000000000006b0 [ 168.503430] Stack: [ 168.503433] ffffffff81315765 ffffffff81079bec 000000971fffa740 ffffffffffffffff [ 168.503440] ffff88011fffa740 ffffffff816d8920 ffffffff816e00a0 ffffffff81719000 [ 168.503446] ffffffff8166edc3 ffffffff816e00a0 0000000000000020 ffffffff8166e120 [ 168.503517] Call Trace: [ 168.503527] [<ffffffff81315765>] ? default_idle+0x5/0x10 [ 168.503534] [<ffffffff81079bec>] ? cpu_startup_entry+0xac/0x150 [ 168.503544] [<ffffffff8166edc3>] ? start_kernel+0x385/0x38d [ 168.503550] [<ffffffff8166e120>] ? early_idt_handler_array+0x120/0x120 [ 168.503556] [<ffffffff8166e375>] ? x86_64_start_kernel+0xea/0xf9 [ 168.503558] Code: 04 25 c0 c2 00 00 f0 80 60 02 df c3 0f ae f0 0f ae 38 0f ae f0 eb c8 fb 66 66 90 66 66 90 eb dd 66 0f 1f 84 00 00 00 00 00 fb f4 <c3> 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 f4 c3 90 90 90 90 90
