Re: [syzbot] INFO: task hung in io_ring_exit_work

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in kvm_wait

------------[ cut here ]------------
raw_local_irq_restore() called with IRQs enabled
WARNING: CPU: 1 PID: 8751 at kernel/locking/irqflag-debug.c:10 warn_bogus_irq_restore+0x1d/0x20 kernel/locking/irqflag-debug.c:10
Modules linked in:
CPU: 1 PID: 8751 Comm: syz-execprog Not tainted 5.12.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:warn_bogus_irq_restore+0x1d/0x20 kernel/locking/irqflag-debug.c:10
Code: bf ff cc cc cc cc cc cc cc cc cc cc cc 80 3d 50 f3 2f 04 00 74 01 c3 48 c7 c7 20 92 6b 89 c6 05 3f f3 2f 04 01 e8 77 2d bf ff <0f> 0b c3 48 39 77 10 0f 84 97 00 00 00 66 f7 47 22 f0 ff 74 4b 48
RSP: 0000:ffffc90000f1fa00 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff88802b5f5d88 RCX: 0000000000000000
RDX: ffff88802b5f54c0 RSI: ffffffff815c3df5 RDI: fffff520001e3f32
RBP: 0000000000000200 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815bcb8e R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10056bebb1 R14: 0000000000000001 R15: ffff8880b9f35f40
FS:  0000000000000000(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000454476 CR3: 0000000013f15000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kvm_wait arch/x86/kernel/kvm.c:860 [inline]
 kvm_wait+0xc9/0xe0 arch/x86/kernel/kvm.c:837
 pv_wait arch/x86/include/asm/paravirt.h:564 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
 __pv_queued_spin_lock_slowpath+0x8b8/0xb40 kernel/locking/qspinlock.c:508
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:554 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:113
 spin_lock include/linux/spinlock.h:354 [inline]
 task_lock include/linux/sched/task.h:168 [inline]
 exit_mm kernel/exit.c:481 [inline]
 do_exit+0xa6f/0x2a60 kernel/exit.c:812
 do_group_exit+0x125/0x310 kernel/exit.c:922
 get_signal+0x47f/0x2150 kernel/signal.c:2781
 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x46ca23
Code: Unable to access opcode bytes at RIP 0x46c9f9.
RSP: 002b:00007ffe5318bb08 EFLAGS: 00000286 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00000000016b3d60 RCX: 000000000046ca23
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000016b3ea8
RBP: 00007ffe5318bb50 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000286 R12: 0000000000000003
R13: 00000000016b39a0 R14: 0000000000000005 R15: 00000000000000aa


Tested on:

commit:         1507b68f io_uring: don't quiesce reg buffer
git tree:       https://github.com/isilence/linux.git syz_test
console output: https://syzkaller.appspot.com/x/log.txt?x=1008508ed00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=86318203e865a02b
dashboard link: https://syzkaller.appspot.com/bug?extid=93f72b3885406bb09e0d
compiler: