============================================
WARNING: possible recursive locking detected
5.16.0-rc5-syzkaller #0 Not tainted
--------------------------------------------
swapper/1/0 is trying to acquire lock:
ffffffff9078e3b0 (&port_lock_key){-.-.}-{2:2}, at: uart_write+0x12c/0x570 drivers/tty/serial/serial_core.c:577
but task is already holding lock:
ffffffff9078e3b0 (&port_lock_key){-.-.}-{2:2}, at: serial8250_handle_irq.part.0+0x21/0x3d0 drivers/tty/serial/8250/8250_port.c:1908
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&port_lock_key);
lock(&port_lock_key);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by swapper/1/0:
#0: ffff88807d320630 (&i->lock){-.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline]
#0: ffff88807d320630 (&i->lock){-.-.}-{2:2}, at: serial8250_interrupt+0x3a/0x200 drivers/tty/serial/8250/8250_core.c:116
#1: ffffffff9078e3b0 (&port_lock_key){-.-.}-{2:2}, at: serial8250_handle_irq.part.0+0x21/0x3d0 drivers/tty/serial/8250/8250_port.c:1908
#2: ffff88807dae6098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x1d/0x80 drivers/tty/tty_ldisc.c:273
stack backtrace:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_deadlock_bug kernel/locking/lockdep.c:2956 [inline]
check_deadlock kernel/locking/lockdep.c:2999 [inline]
validate_chain kernel/locking/lockdep.c:3788 [inline]
__lock_acquire.cold+0x149/0x3ab kernel/locking/lockdep.c:5027
lock_acquire kernel/locking/lockdep.c:5637 [inline]
lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162
uart_write+0x12c/0x570 drivers/tty/serial/serial_core.c:577
n_hdlc_send_frames+0x24b/0x490 drivers/tty/n_hdlc.c:290
tty_wakeup+0xe1/0x120 drivers/tty/tty_io.c:534
tty_port_default_wakeup+0x26/0x40 drivers/tty/tty_port.c:51
serial8250_tx_chars+0x4f3/0xad0 drivers/tty/serial/8250/8250_port.c:1845
serial8250_handle_irq.part.0+0x328/0x3d0 drivers/tty/serial/8250/8250_port.c:1932
serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1905 [inline]
serial8250_default_handle_irq+0xb2/0x220 drivers/tty/serial/8250/8250_port.c:1949
serial8250_interrupt+0xfd/0x200 drivers/tty/serial/8250/8250_core.c:126
__handle_irq_event_percpu+0x303/0x8f0 kernel/irq/handle.c:158
handle_irq_event_percpu kernel/irq/handle.c:198 [inline]
handle_irq_event+0x102/0x280 kernel/irq/handle.c:215
handle_edge_irq+0x25f/0xd00 kernel/irq/chip.c:822
generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
handle_irq arch/x86/kernel/irq.c:231 [inline]
__common_interrupt+0x9d/0x210 arch/x86/kernel/irq.c:250
common_interrupt+0xa4/0xc0 arch/x86/kernel/irq.c:240
</IRQ>
<TASK>
asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:629
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:132 [inline]
RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:110 [inline]
RIP: 0010:acpi_idle_do_entry+0x1c6/0x250 drivers/acpi/processor_idle.c:553
Code: 89 de e8 dd 6c 30 f8 84 db 75 ac e8 f4 68 30 f8 e8 3f ad 36 f8 eb 0c e8 e8 68 30 f8 0f 00 2d 31 c4 c9 00 e8 dc 68 30 f8 fb f4 <9c> 5b 81 e3 00 02 00 00 fa 31 ff 48 89 de e8 57 6b 30 f8 48 85 db
RSP: 0018:ffffc90000d57d18 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888011955700 RSI: ffffffff894748f4 RDI: 0000000000000000
RBP: ffff8880125f8864 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff817df658 R11: 0000000000000000 R12: 0000000000000001
R13: ffff8880125f8800 R14: ffff8880125f8864 R15: ffff888146c08004
acpi_idle_enter+0x361/0x500 drivers/acpi/processor_idle.c:688
cpuidle_enter_state+0x1b1/0xc80 drivers/cpuidle/cpuidle.c:237
cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:351
call_cpuidle kernel/sched/idle.c:158 [inline]
cpuidle_idle_call kernel/sched/idle.c:239 [inline]
do_idle+0x3e8/0x590 kernel/sched/idle.c:306
cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403
start_secondary+0x265/0x340 arch/x86/kernel/smpboot.c:272
secondary_startup_64_no_verify+0xb0/0xbb
</TASK>
----------------
Code disassembly (best guess):
0: 89 de mov %ebx,%esi
2: e8 dd 6c 30 f8 callq 0xf8306ce4
7: 84 db test %bl,%bl
9: 75 ac jne 0xffffffb7
b: e8 f4 68 30 f8 callq 0xf8306904
10: e8 3f ad 36 f8 callq 0xf836ad54
15: eb 0c jmp 0x23
17: e8 e8 68 30 f8 callq 0xf8306904
1c: 0f 00 2d 31 c4 c9 00 verw 0xc9c431(%rip) # 0xc9c454
23: e8 dc 68 30 f8 callq 0xf8306904
28: fb sti
29: f4 hlt
* 2a: 9c pushfq <-- trapping instruction
2b: 5b pop %rbx
2c: 81 e3 00 02 00 00 and $0x200,%ebx
32: fa cli
33: 31 ff xor %edi,%edi
35: 48 89 de mov %rbx,%rsi
38: e8 57 6b 30 f8 callq 0xf8306b94
3d: 48 85 db test %rbx,%rbx