=============================
[ BUG: Invalid wait context ]
syzkaller #0 Not tainted
-----------------------------
syz.3.2774/16818 is trying to lock:
ffff888024d852e0 (&gpc->lock){....}-{3:3}, at: kvm_xen_set_evtchn_fast+0x253/0xe80 arch/x86/kvm/xen.c:1820
other info that might help us debug this:
context-{2:2}
2 locks held by syz.3.2774/16818:
 #0: ffff88801345e638 (&u->iolock){+.+.}-{4:4}, at: __unix_dgram_recvmsg+0x255/0xc30 net/unix/af_unix.c:2568
 #1: ffff888024d85840 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline]
 #1: ffff888024d85840 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline]
 #1: ffff888024d85840 (&kvm->srcu){.?.+}-{0:0}, at: kvm_xen_set_evtchn_fast+0x245/0xe80 arch/x86/kvm/xen.c:1818
stack backtrace:
CPU: 0 UID: 0 PID: 16818 Comm: syz.3.2774 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_lock_invalid_wait_context kernel/locking/lockdep.c:4830 [inline]
 check_wait_context kernel/locking/lockdep.c:4902 [inline]
 __lock_acquire+0xfa4/0x2630 kernel/locking/lockdep.c:5187
 lock_acquire kernel/locking/lockdep.c:5868 [inline]
 lock_acquire+0x1cf/0x380 kernel/locking/lockdep.c:5825
 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:172 [inline]
 _raw_read_lock_irqsave+0x46/0x90 kernel/locking/spinlock.c:236
 kvm_xen_set_evtchn_fast+0x253/0xe80 arch/x86/kvm/xen.c:1820
 xen_timer_callback+0x1db/0x2a0 arch/x86/kvm/xen.c:140
 __run_hrtimer kernel/time/hrtimer.c:1785 [inline]
 __hrtimer_run_queues+0x1ad/0xa70 kernel/time/hrtimer.c:1849
 hrtimer_interrupt+0x397/0x8c0 kernel/time/hrtimer.c:1911
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
 __sysvec_apic_timer_interrupt+0x109/0x490 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 d6 ba 55 f6 48 89 df e8 be 0a 56 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 <bf> 01 00 00 00 e8 25 41 46 f6 65 8b 05 9e de 7d 08 85 c0 74 16 5b
RSP: 0018:ffffc90003bf7718 EFLAGS: 00000246
RAX: 0000000000000006 RBX: ffff88801345e140 RCX: 0000000000000040
RDX: 0000000000000000 RSI: ffffffff8de752e8 RDI: ffffffff8c1adb20
RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff888029bbe500
R13: 0000000000000246 R14: ffff88801345e128 R15: ffffc90003bf7898
 spin_unlock_irqrestore include/linux/spinlock.h:407 [inline]
 __skb_try_recv_datagram+0x16a/0x500 net/core/datagram.c:267
 __unix_dgram_recvmsg+0x1bc/0xc30 net/unix/af_unix.c:2571
 unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2670
 sock_recvmsg_nosec net/socket.c:1078 [inline]
 ____sys_recvmsg+0x5f7/0x6b0 net/socket.c:2810
 ___sys_recvmsg+0x16a/0x1a0 net/socket.c:2854
 do_recvmmsg+0x563/0x760 net/socket.c:2941
 __sys_recvmmsg+0x21f/0x270 net/socket.c:3023
 __do_compat_sys_recvmmsg_time32 net/compat.c:418 [inline]
 __se_compat_sys_recvmmsg_time32 net/compat.c:414 [inline]
 __ia32_compat_sys_recvmmsg_time32+0xc4/0x160 net/compat.c:414
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xe3/0x8c0 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f76f6c
Code: d2 74 05 c1 e8 0c 89 02 8b 5d fc 31 c0 c9 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 58 b8 77 00 00 00 cd 80 0f 0b 8d b6 00 00 00 00 b8 ad
RSP: 002b:00000000f541550c EFLAGS: 00000292 ORIG_RAX: 0000000000000151
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 00000000800000c0
RDX: 0000000000010106 RSI: 0000000000000002 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess):
   0:	f5                   	cmc
   1:	53                   	push   %rbx
   2:	48 8b 74 24 10       	mov    0x10(%rsp),%rsi
   7:	48 89 fb             	mov    %rdi,%rbx
   a:	48 83 c7 18          	add    $0x18,%rdi
   e:	e8 d6 ba 55 f6       	call   0xf655bae9
  13:	48 89 df             	mov    %rbx,%rdi
  16:	e8 be 0a 56 f6       	call   0xf6560ad9
  1b:	f7 c5 00 02 00 00    	test   $0x200,%ebp
  21:	75 23                	jne    0x46
  23:	9c                   	pushf
  24:	58                   	pop    %rax
  25:	f6 c4 02             	test   $0x2,%ah
  28:	75 37                	jne    0x61
* 2a:	bf 01 00 00 00       	mov    $0x1,%edi <-- trapping instruction
  2f:	e8 25 41 46 f6       	call   0xf6464159
  34:	65 8b 05 9e de 7d 08 	mov    %gs:0x87dde9e(%rip),%eax        # 0x87dded9
  3b:	85 c0                	test   %eax,%eax
  3d:	74 16                	je     0x55
  3f:	5b                   	pop    %rbx