Is this a bug?
From: Peter Teoh
Date: Tue Jun 20 2017 - 23:08:22 EST
I got this crashdump inside QEMU (running 4.11.0 stable):
[ 0.588497] pci 0000:00:01.0: Activating ISA DMA hang workarounds
[ 1.778428] ACPI: PCI Interrupt Link [LNKD] enabled at IRQ 11
[ 2.991744] pci 0000:00:02.0: Video device with shadowed ROM at
[mem 0x000c0000-0x000dffff]
[ 2.992993] Unpacking initramfs...
[ 453.628449] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 21s!
[swapper/0:1]
[ 453.629130] Modules linked in:
[ 453.629370] irq event stamp: 6845090
[ 453.629710] hardirqs last enabled at (6845089):
[<ffffffff816b8c6c>] mem_cgroup_commit_charge+0x15c/0x2f0
[ 453.630462] hardirqs last disabled at (6845090):
[<ffffffff82cf51ee>] apic_timer_interrupt+0x8e/0xa0
[ 453.631147] softirqs last enabled at (6844578):
[<ffffffff82cf9dd4>] __do_softirq+0x664/0x883
[ 453.631780] softirqs last disabled at (6844571):
[<ffffffff8118cc53>] irq_exit+0x1a3/0x1d0
[ 453.632359] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.11.0syz #7
[ 453.632890] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[ 453.633605] task: ffff880064a48040 task.stack: ffff880064a50000
[ 453.634113] RIP: 0010:__memset+0x24/0x30
[ 453.634384] RSP: 0000:ffff880064a576a0 EFLAGS: 00010206 ORIG_RAX:
ffffffffffffff10
[ 453.634901] RAX: 0000000000000000 RBX: ffff8800378001e0 RCX: 00000000000001c4
[ 453.635366] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8800378001e0
[ 453.635829] RBP: ffff880064a576c0 R08: 0000000000000000 R09: ffff8800378001e0
[ 453.636290] R10: ffff880037800fff R11: 0000000000000000 R12: 0000000000000e20
[ 453.636826] R13: 0000000000000000 R14: ffff880064a48040 R15: 00000000000001e0
[ 453.637320] FS: 0000000000000000(0000) GS:ffff880065400000(0000)
knlGS:0000000000000000
[ 453.637835] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 453.638208] CR2: 0000000000000000 CR3: 0000000003613000 CR4: 00000000000006f0
[ 453.638684] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 453.639339] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 453.639944] Call Trace:
[ 453.640119] ? memset+0x31/0x40
[ 453.640436] simple_write_begin+0x18f/0x2b0
[ 453.640799] generic_perform_write+0x274/0x520
[ 453.641204] ? __page_cache_alloc+0x310/0x310
[ 453.641532] ? file_update_time+0xce/0x3d0
[ 453.641821] ? current_time+0xd0/0xd0
[ 453.642135] ? lock_acquire+0x17d/0x350
[ 453.642457] __generic_file_write_iter+0x32f/0x5b0
[ 453.642806] generic_file_write_iter+0x2ea/0x600
[ 453.643162] __vfs_write+0x3d4/0x650
[ 453.643435] ? vfs_iter_write+0x550/0x550
[ 453.643772] ? rcu_sync_lockdep_assert+0x78/0xb0
[ 453.644092] ? __sb_start_write+0x1ed/0x2b0
[ 453.644499] vfs_write+0x175/0x4e0
[ 453.644741] SyS_write+0xe8/0x1d0
[ 453.644996] ? SyS_read+0x1d0/0x1d0
[ 453.645275] ? zlib_inflate+0x282/0x5d40
[ 453.645574] xwrite+0x36/0x8a
[ 453.645831] do_copy+0xb5/0xf6
[ 453.646070] write_buffer+0x5d/0x77
[ 453.646387] flush_buffer+0x3a/0xff
[ 453.646658] __gunzip+0x64e/0x7e6
[ 453.646929] ? bunzip2+0x980/0x980
[ 453.647164] ? write_buffer+0x77/0x77
[ 453.647461] ? write_buffer+0x77/0x77
[ 453.647721] gunzip+0x43/0x52
[ 453.647942] ? md_run_setup+0xad/0xad
[ 453.648225] ? __gunzip+0x7e6/0x7e6
[ 453.648535] unpack_to_rootfs+0x284/0x527
[ 453.648822] ? md_run_setup+0xad/0xad
[ 453.649091] ? do_reset+0x91/0x91
[ 453.649377] populate_rootfs+0x116/0x344
[ 453.649657] ? maybe_link.part.5+0x31c/0x31c
[ 453.650089] do_one_initcall+0xb9/0x290
[ 453.650384] ? initcall_blacklisted+0x1b0/0x1b0
[ 453.650732] ? parse_args+0x228/0xb60
[ 453.651008] kernel_init_freeable+0x49a/0x54e
[ 453.651348] ? rest_init+0x190/0x190
[ 453.651650] kernel_init+0x18/0x180
[ 453.651965] ? rest_init+0x190/0x190
[ 453.652223] ret_from_fork+0x31/0x40
[ 453.652543] Code: 90 90 90 90 90 90 90 0f 1f 44 00 00 49 89 f9 48
89 d1 83 e2 07 48 c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01
48 0f af c6 <f3> 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48
89 d1
[ 530.660850] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 21s!
[swapper/0:1]
[ 530.661442] Modules linked in:
[ 530.661679] irq event stamp: 6876482
[ 530.661939] hardirqs last enabled at (6876481):
[<ffffffff816b8c6c>] mem_cgroup_commit_charge+0x15c/0x2f0
[ 530.662715] hardirqs last disabled at (6876482):
[<ffffffff82cf51ee>] apic_timer_interrupt+0x8e/0xa0
[ 530.663385] softirqs last enabled at (6876448):
[<ffffffff82cf9dd4>] __do_softirq+0x664/0x883
[ 530.664000] softirqs last disabled at (6876441):
[<ffffffff8118cc53>] irq_exit+0x1a3/0x1d0
[ 530.664728] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G L
4.11.0syz #7
[ 530.665360] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[ 530.666139] task: ffff880064a48040 task.stack: ffff880064a50000
[ 530.666649] RIP: 0010:__memcpy+0x12/0x20
[ 530.667065] RSP: 0000:ffff880064a57670 EFLAGS: 00010246 ORIG_RAX:
ffffffffffffff10
[ 530.668093] RAX: ffff8800aac00000 RBX: 0000000000001000 RCX: 0000000000000200
[ 530.668694] RDX: 0000000000000000 RSI: ffff8800627fc394 RDI: ffff8800aac00000
[ 530.669348] RBP: ffff880064a57690 R08: 0000000000000000 R09: ffffed00155801ff
[ 530.669978] R10: ffff8800aac00fff R11: 0000000000000000 R12: ffff8800aac00000
[ 530.670715] R13: ffff8800627fc394 R14: ffffffff82f737c0 R15: ffff880064a57948
[ 530.671329] FS: 0000000000000000(0000) GS:ffff880065400000(0000)
knlGS:0000000000000000
[ 530.672049] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 530.672560] CR2: 0000000000000000 CR3: 0000000003613000 CR4: 00000000000006f0
[ 530.673212] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 530.673818] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 530.674432] Call Trace:
[ 530.674717] ? memcpy+0x45/0x50
[ 530.675051] iov_iter_copy_from_user_atomic+0x67d/0x8a0
[ 530.675537] ? grab_cache_page_write_begin+0x8b/0xa0
[ 530.675999] generic_perform_write+0x2df/0x520
[ 530.676397] ? __mark_inode_dirty+0x2c0/0xe90
[ 530.676816] ? __page_cache_alloc+0x310/0x310
[ 530.677269] ? __mnt_drop_write_file+0x12/0x70
[ 530.677686] ? file_update_time+0xce/0x3d0
[ 530.678047] ? current_time+0xd0/0xd0
[ 530.678422] ? lock_acquire+0x17d/0x350
[ 530.678795] __generic_file_write_iter+0x32f/0x5b0
[ 530.679240] generic_file_write_iter+0x2ea/0x600
[ 530.679643] __vfs_write+0x3d4/0x650
[ 530.680038] ? vfs_iter_write+0x550/0x550
[ 530.680440] ? rcu_sync_lockdep_assert+0x78/0xb0
[ 530.680900] ? __sb_start_write+0x1ed/0x2b0
[ 530.681313] vfs_write+0x175/0x4e0
[ 530.681676] SyS_write+0xe8/0x1d0
[ 530.681966] ? SyS_read+0x1d0/0x1d0
[ 530.682306] ? zlib_inflate+0x282/0x5d40
[ 530.682684] xwrite+0x36/0x8a
[ 530.682988] do_copy+0xb5/0xf6
[ 530.683396] write_buffer+0x5d/0x77
[ 530.683741] flush_buffer+0x3a/0xff
[ 530.684264] __gunzip+0x64e/0x7e6
[ 530.684741] ? bunzip2+0x980/0x980
[ 530.685084] ? write_buffer+0x77/0x77
[ 530.685481] ? write_buffer+0x77/0x77
[ 530.685840] gunzip+0x43/0x52
[ 530.686152] ? md_run_setup+0xad/0xad
[ 530.686559] ? __gunzip+0x7e6/0x7e6
[ 530.686897] unpack_to_rootfs+0x284/0x527
[ 530.687279] ? md_run_setup+0xad/0xad
[ 530.687628] ? do_reset+0x91/0x91
[ 530.688028] populate_rootfs+0x116/0x344
[ 530.688429] ? maybe_link.part.5+0x31c/0x31c
[ 530.688874] do_one_initcall+0xb9/0x290
[ 530.689244] ? initcall_blacklisted+0x1b0/0x1b0
[ 530.689760] ? parse_args+0x228/0xb60
[ 530.690138] kernel_init_freeable+0x49a/0x54e
[ 530.690542] ? rest_init+0x190/0x190
[ 530.690916] kernel_init+0x18/0x180
[ 530.691320] ? rest_init+0x190/0x190
[ 530.691762] ret_from_fork+0x31/0x40
[ 530.692127] Code: 90 ff e9 4d ff ff ff e8 ad bb 90 ff eb 8f e8 a6
bb 90 ff e9 66 ff ff ff 90 0f 1f 44 00 00 48 89 f8 48 89 d1 48 c1 e9
03 83 e2 07 <f3> 48 a5 89 d1 f3 a4 c3 66 0f 1f 44 00 00 48 89 f8 48 89
d1 f3
Not sure if the QEMU reboot itself or not
--
Regards,
Peter Teoh