INFO: rcu_sched self-detected stall on CPU
INFO: rcu_sched detected stalls on CPUs/tasks:
0-....: (125000 ticks this GP) idle=b52/140000000000001/0 softirq=15059/15059 fqs=31231
(detected by 1, t=125002 jiffies, g=7911, c=7910, q=576)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5931 Comm: syz-executor5 Not tainted 4.15.0-rc1+ #115
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: 00000000a6a5dcca task.stack: 000000007e19b09e
RIP: 0010:inb arch/x86/include/asm/io.h:348 [inline]
RIP: 0010:io_serial_in+0x6b/0x90 drivers/tty/serial/8250/8250_port.c:434
RSP: 0018:ffff8801db406ff8 EFLAGS: 00000002
RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000005 RDI: ffffffff87ced9c0
RBP: ffff8801db407008 R08: 0000000000000002 R09: 000000000000000c
R10: 0000000000000000 R11: ffffffff87489d60 R12: ffffffff87ced980
R13: 0000000000000020 R14: fffffbfff0f9db77 R15: fffffbfff0f9db3a
FS: 0000000000000000(0000) GS:ffff8801db400000(0063) knlGS:00000000f7701b40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000020000000 CR3: 00000001d3ce6000 CR4: 00000000001426f0
DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:111 [inline]
wait_for_xmitr+0x93/0x1e0 drivers/tty/serial/8250/8250_port.c:2033
serial8250_console_putchar+0x1f/0x60 drivers/tty/serial/8250/8250_port.c:3170
uart_console_write+0xac/0xe0 drivers/tty/serial/serial_core.c:1858
serial8250_console_write+0x647/0xa20 drivers/tty/serial/8250/8250_port.c:3236
univ8250_console_write+0x5f/0x70 drivers/tty/serial/8250/8250_core.c:590
call_console_drivers kernel/printk/printk.c:1574 [inline]
console_unlock+0x788/0xd80 kernel/printk/printk.c:2233
vprintk_emit+0x4ad/0x590 kernel/printk/printk.c:1757
vprintk_default+0x28/0x30 kernel/printk/printk.c:1796
vprintk_func+0x57/0xc0 kernel/printk/printk_safe.c:379
printk+0xaa/0xca kernel/printk/printk.c:1829
print_cpu_stall_info_begin kernel/rcu/tree_plugin.h:1657 [inline]
print_cpu_stall kernel/rcu/tree.c:1594 [inline]
check_cpu_stall.isra.64+0x845/0x15b0 kernel/rcu/tree.c:1676
__rcu_pending kernel/rcu/tree.c:3440 [inline]
rcu_pending kernel/rcu/tree.c:3502 [inline]
rcu_check_callbacks+0x256/0xd00 kernel/rcu/tree.c:2842
update_process_times+0x30/0x60 kernel/time/timer.c:1630
tick_sched_handle+0x85/0x160 kernel/time/tick-sched.c:162
tick_sched_timer+0x42/0x120 kernel/time/tick-sched.c:1166
__run_hrtimer kernel/time/hrtimer.c:1211 [inline]
__hrtimer_run_queues+0x349/0xe10 kernel/time/hrtimer.c:1275
hrtimer_interrupt+0x1d4/0x5f0 kernel/time/hrtimer.c:1309
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
smp_apic_timer_interrupt+0x14a/0x700 arch/x86/kernel/apic/apic.c:1050
apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:795
RIP: 0010:loop_set_fd drivers/block/loop.c:885 [inline]
RIP: 0010:lo_ioctl+0x5e4/0x1b90 drivers/block/loop.c:1358
RSP: 0018:ffff8801c1ec7bd8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff11
RAX: 0000000000010000 RBX: dffffc0000000000 RCX: ffffffff838b2881
RDX: 1ffff10039edb65e RSI: ffffc9000285f000 RDI: ffff8801cf6db2f0
RBP: ffff8801c1ec7c50 R08: ffffffff85f44600 R09: 1ffff100383d8f24
R10: ffff8801c0e3e180 R11: 0000000000000001 R12: ffff8801cf6db200
R13: ffff8801d4f27b00 R14: ffff8801cf6b0780 R15: ffff8801d4f27c58
lo_compat_ioctl+0xab/0x140 drivers/block/loop.c:1556
compat_blkdev_ioctl+0x3ba/0x1850 block/compat_ioctl.c:406
C_SYSC_ioctl fs/compat_ioctl.c:1473 [inline]
compat_SyS_ioctl+0x151/0x2a30 fs/compat_ioctl.c:1419
do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline]
do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389
entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:125
RIP: 0023:0xf7f05c79
RSP: 002b:00000000f770108c EFLAGS: 00000296 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000015 RCX: 0000000000004c00
RDX: 0000000000000013 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Code: 24 d9 00 00 00 49 8d 7c 24 40 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 d3 e3 80 3c 02 00 75 17 41 03 5c 24 40 89 da ec <5b> 0f b6 c0 41 5c 5d c3 e8 b8 cd 18 ff eb c2 e8 11 ce 18 ff eb
0-....: (125000 ticks this GP) idle=b52/140000000000001/0 softirq=15059/15059 fqs=31396
(t=125663 jiffies g=7911 c=7910 q=576)
NMI backtrace for cpu 0
CPU: 0 PID: 5931 Comm: syz-executor5 Not tainted 4.15.0-rc1+ #115
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x257 lib/dump_stack.c:53
nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103
nmi_trigger_cpumask_backtrace+0x122/0x180 lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
trigger_single_cpu_backtrace include/linux/nmi.h:156 [inline]
rcu_dump_cpu_stacks+0x186/0x1d5 kernel/rcu/tree.c:1459
print_cpu_stall kernel/rcu/tree.c:1608 [inline]
check_cpu_stall.isra.64+0xbb8/0x15b0 kernel/rcu/tree.c:1676
__rcu_pending kernel/rcu/tree.c:3440 [inline]
rcu_pending kernel/rcu/tree.c:3502 [inline]
rcu_check_callbacks+0x256/0xd00 kernel/rcu/tree.c:2842
update_process_times+0x30/0x60 kernel/time/timer.c:1630
tick_sched_handle+0x85/0x160 kernel/time/tick-sched.c:162
tick_sched_timer+0x42/0x120 kernel/time/tick-sched.c:1166
__run_hrtimer kernel/time/hrtimer.c:1211 [inline]
__hrtimer_run_queues+0x349/0xe10 kernel/time/hrtimer.c:1275
hrtimer_interrupt+0x1d4/0x5f0 kernel/time/hrtimer.c:1309
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
smp_apic_timer_interrupt+0x14a/0x700 arch/x86/kernel/apic/apic.c:1050
apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:795
RIP: 0010:loop_set_fd drivers/block/loop.c:885 [inline]
RIP: 0010:lo_ioctl+0x5e4/0x1b90 drivers/block/loop.c:1358
RSP: 0018:ffff8801c1ec7bd8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff11
RAX: 0000000000010000 RBX: dffffc0000000000 RCX: ffffffff838b2881
RDX: 1ffff10039edb65e RSI: ffffc9000285f000 RDI: ffff8801cf6db2f0
RBP: ffff8801c1ec7c50 R08: ffffffff85f44600 R09: 1ffff100383d8f24
R10: ffff8801c0e3e180 R11: 0000000000000001 R12: ffff8801cf6db200
R13: ffff8801d4f27b00 R14: ffff8801cf6b0780 R15: ffff8801d4f27c58
lo_compat_ioctl+0xab/0x140 drivers/block/loop.c:1556
compat_blkdev_ioctl+0x3ba/0x1850 block/compat_ioctl.c:406
C_SYSC_ioctl fs/compat_ioctl.c:1473 [inline]
compat_SyS_ioctl+0x151/0x2a30 fs/compat_ioctl.c:1419
do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline]
do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389
entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:125
RIP: 0023:0xf7f05c79
RSP: 002b:00000000f770108c EFLAGS: 00000296 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000015 RCX: 0000000000004c00
RDX: 0000000000000013 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
INFO: rcu_sched detected expedited stalls on CPUs/tasks: { 0-... } 125971 jiffies s: 465 root: 0x1/.
blocking rcu_node structures:
Task dump for CPU 0:
syz-executor5 R running task 24984 5931 3326 0xa002000c
Call Trace: