From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: MIME-Version: 1.0 References: <0000000000009d327505b0999237@google.com> In-Reply-To: <0000000000009d327505b0999237@google.com> From: Dmitry Vyukov Date: Thu, 1 Oct 2020 12:46:41 +0200 Message-ID: Subject: Re: INFO: rcu detected stall in batadv_nc_worker (3) Content-Type: text/plain; charset="UTF-8" List-Id: The list for a Better Approach To Mobile Ad-hoc Networking List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: syzbot , mareklindner@neomailbox.ch, sw@simonwunderlich.de, a@unstable.cc, Sven Eckelmann , David Miller , Jakub Kicinski , b.a.t.m.a.n@lists.open-mesh.org, netdev Cc: LKML , syzkaller-bugs , Thomas Gleixner On Thu, Oct 1, 2020 at 12:35 PM syzbot wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: fffe3ae0 Merge tag 'for-linus-hmm' of git://git.kernel.org.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=17e03342900000 > kernel config: https://syzkaller.appspot.com/x/.config?x=226c7a97d80bec54 > dashboard link: https://syzkaller.appspot.com/bug?extid=69904c3b4a09e8fa2e1b > compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) > > Unfortunately, I don't have any reproducer for this issue yet. > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+69904c3b4a09e8fa2e1b@syzkaller.appspotmail.com +batadv maintainers May be related to: KMSAN: uninit-value in batadv_nc_worker https://syzkaller.appspot.com/bug?extid=da9194708de785081f11 > rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: > rcu: 0-...!: (1 GPs behind) idle=22e/1/0x4000000000000000 softirq=85361/85365 fqs=8 > (detected by 1, t=10502 jiffies, g=114061, q=1511) > Sending NMI from CPU 1 to CPUs 0: > NMI backtrace for cpu 0 > CPU: 0 PID: 194 Comm: kworker/u4:4 Not tainted 5.8.0-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Workqueue: bat_events batadv_nc_worker > RIP: 0010:arch_local_save_flags arch/x86/include/asm/paravirt.h:765 [inline] > RIP: 0010:arch_local_irq_save arch/x86/include/asm/paravirt.h:787 [inline] > RIP: 0010:__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] > RIP: 0010:_raw_spin_lock_irqsave+0x3c/0xc0 kernel/locking/spinlock.c:159 > Code: 03 49 bf 00 00 00 00 00 fc ff df 42 80 3c 38 00 74 0c 48 c7 c7 b0 d5 4b 89 e8 a0 97 92 f9 48 83 3d 38 61 2a 01 00 74 79 9c 58 <0f> 1f 44 00 00 49 89 c6 48 c7 c0 c0 d5 4b 89 48 c1 e8 03 42 80 3c > RSP: 0018:ffffc90000007d40 EFLAGS: 00000082 > RAX: 0000000000000082 RBX: ffffffff8ba182b8 RCX: 000000000000d6e0 > RDX: 0000000080010001 RSI: ffffffff894eec80 RDI: ffffffff8ba182b8 > RBP: ffffffff894eec80 R08: ffffffff816542f4 R09: fffff52000000fb0 > R10: fffff52000000fb0 R11: 0000000000000000 R12: dffffc0000000000 > R13: 1ffff11015d04ed2 R14: dffffc0000000000 R15: dffffc0000000000 > FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00000000004ddaf0 CR3: 0000000090ca1000 CR4: 00000000001506f0 > DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 > Call Trace: > > debug_object_activate+0x62/0x5f0 lib/debugobjects.c:636 > debug_hrtimer_activate kernel/time/hrtimer.c:416 [inline] > debug_activate kernel/time/hrtimer.c:476 [inline] > enqueue_hrtimer kernel/time/hrtimer.c:965 [inline] > __run_hrtimer kernel/time/hrtimer.c:1537 [inline] > __hrtimer_run_queues+0x510/0x930 kernel/time/hrtimer.c:1584 > hrtimer_interrupt+0x373/0xd60 kernel/time/hrtimer.c:1646 > local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] > __sysvec_apic_timer_interrupt+0xf0/0x260 arch/x86/kernel/apic/apic.c:1097 > asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 > > __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] > run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] > sysvec_apic_timer_interrupt+0x94/0xf0 arch/x86/kernel/apic/apic.c:1091 > asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 > RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:770 [inline] > RIP: 0010:lock_release+0x3c4/0x750 kernel/locking/lockdep.c:5026 > Code: 48 c1 e8 03 42 80 3c 28 00 74 0c 48 c7 c7 b8 d5 4b 89 e8 3f 0b 5a 00 48 83 3d df d4 f1 07 00 0f 84 5c 03 00 00 4c 89 e7 57 9d <0f> 1f 44 00 00 65 48 8b 04 25 28 00 00 00 48 3b 44 24 50 0f 85 40 > RSP: 0018:ffffc90001037bf8 EFLAGS: 00000282 > RAX: 1ffffffff1297ab7 RBX: 1ffff110151d2949 RCX: ffff8880a8e94180 > RDX: ffff8880a8e94a48 RSI: ffffffff894ea290 RDI: 0000000000000282 > RBP: 9644b5a36c253f0c R08: dffffc0000000000 R09: fffffbfff131b08e > R10: fffffbfff131b08e R11: 0000000000000000 R12: 0000000000000282 > R13: dffffc0000000000 R14: dffffc0000000000 R15: ffff8880a8e94a4c > rcu_read_unlock include/linux/rcupdate.h:688 [inline] > batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:411 [inline] > batadv_nc_worker+0x261/0x5c0 net/batman-adv/network-coding.c:718 > process_one_work+0x789/0xfc0 kernel/workqueue.c:2269 > worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415 > kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > rcu: rcu_preempt kthread starved for 10486 jiffies! g114061 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 > rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. > rcu: RCU grace-period kthread stack dump: > rcu_preempt I28608 10 2 0x00004000 > Call Trace: > context_switch kernel/sched/core.c:3778 [inline] > __schedule+0x979/0xce0 kernel/sched/core.c:4527 > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/0000000000009d327505b0999237%40google.com.