From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753229AbeDLVCE (ORCPT ); Thu, 12 Apr 2018 17:02:04 -0400 Received: from mail-io0-f198.google.com ([209.85.223.198]:54855 "EHLO mail-io0-f198.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753106AbeDLVCC (ORCPT ); Thu, 12 Apr 2018 17:02:02 -0400 X-Google-Smtp-Source: AIpwx4+UKuiZPc1a2BY//rdX+eGf5j/fve9ifojuVzBOJlJxrxp6WdQ0WgnFrramK4zB76f+5DcHFcQdoHM5n4uvUP8WBkYPpL65 MIME-Version: 1.0 Date: Thu, 12 Apr 2018 14:02:01 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000237cc60569ad11c7@google.com> Subject: INFO: rcu detected stall in d_walk From: syzbot To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id w3CL2AtY015957 Hello, syzbot hit the following crash on upstream commit c17b0aadb7d8f87de56a4a374a8131519c0f7422 (Thu Apr 12 16:15:48 2018 +0000) Merge tag 'asm-generic' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic syzbot dashboard link: https://syzkaller.appspot.com/bug?extid=ae80b790eb412884ca77 So far this crash happened 3 times on upstream. C reproducer: https://syzkaller.appspot.com/x/repro.c?id=6595600812343296 syzkaller reproducer: https://syzkaller.appspot.com/x/repro.syz?id=6204964946837504 Raw console output: https://syzkaller.appspot.com/x/log.txt?id=5012331448762368 Kernel config: https://syzkaller.appspot.com/x/.config?id=-5947642240294114534 compiler: gcc (GCC) 8.0.1 20180301 (experimental) IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+ae80b790eb412884ca77@syzkaller.appspotmail.com It will help syzbot understand when the bug is fixed. See footer for details. If you forward the report, please keep this part and the footer. EXT4-fs (sda1): Unrecognized mount option "�辭 m��.2�-[)3i�~�r��$S�%j�?� ��ƅ�|��1��>�[��2 H�s�no[�n�߲$��;��g� �X��m�64"�N=�BM�Z��H��#�� )1{��^f��D�.`*�e��B�8H8��O�" or missing value EXT4-fs (sda1): Unrecognized mount option "�辭 m��.2�-[)3i�~�r��$S�%j�?� ��ƅ�|��1��>�[��2 H�s�no[�n�߲$��;��g� �X��m�64"�N=�BM�Z��H��#�� )1{��^f��D�.`*�e��B�8H8��O�" or missing value INFO: rcu_sched detected stalls on CPUs/tasks: (detected by 1, t=125007 jiffies, g=5317, c=5316, q=46) All QSes seen, last rcu_sched kthread activity 125016 (4295416981-4295291965), jiffies_till_next_fqs=3, root ->qsmask 0x0 syzkaller106625 R running task 21976 4551 4549 0x00000008 Call Trace: sched_show_task.cold.87+0x27a/0x301 kernel/sched/core.c:5325 print_other_cpu_stall.cold.79+0x92f/0x9d2 kernel/rcu/tree.c:1481 check_cpu_stall.isra.61+0x706/0xf50 kernel/rcu/tree.c:1599 __rcu_pending kernel/rcu/tree.c:3356 [inline] rcu_pending kernel/rcu/tree.c:3401 [inline] rcu_check_callbacks+0x21b/0xad0 kernel/rcu/tree.c:2763 update_process_times+0x2d/0x70 kernel/time/timer.c:1636 tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:173 tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1283 __run_hrtimer kernel/time/hrtimer.c:1386 [inline] __hrtimer_run_queues+0x3e3/0x10a0 kernel/time/hrtimer.c:1448 hrtimer_interrupt+0x286/0x650 kernel/time/hrtimer.c:1506 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline] smp_apic_timer_interrupt+0x15d/0x710 arch/x86/kernel/apic/apic.c:1050 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:862 RIP: 0010:list_empty include/linux/list.h:203 [inline] RIP: 0010:select_collect+0x175/0x5f0 fs/dcache.c:1465 RSP: 0018:ffff8801c79e78e8 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffff8801d95765c0 RBX: 1ffff10038f3cf20 RCX: ffffffff81c1ff94 RDX: 0000000000000000 RSI: ffffffff81c20025 RDI: ffff8801c79e7c08 RBP: ffff8801c79e79c8 R08: ffff8801d95765c0 R09: ffffed0034ffdec8 R10: ffffed0034ffdec8 R11: ffff8801a7fef643 R12: ffff8801c79e7bf0 R13: ffff8801a7fef5c0 R14: ffff8801c79e7bf8 R15: ffff8801c79e79a0 d_walk+0x3c3/0xc80 fs/dcache.c:1276 shrink_dcache_parent+0x179/0x230 fs/dcache.c:1486 vfs_rmdir+0x202/0x470 fs/namei.c:3850 do_rmdir+0x523/0x610 fs/namei.c:3911 SYSC_rmdir fs/namei.c:3929 [inline] SyS_rmdir+0x1a/0x20 fs/namei.c:3927 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4423c7 RSP: 002b:00007ffe66511a38 EFLAGS: 00000207 ORIG_RAX: 0000000000000054 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00000000004423c7 RDX: 0000000000000000 RSI: 00000000006d45f8 RDI: 00007ffe66513250 RBP: 00007ffe66513250 R08: 0000000000000000 R09: 0000000000000001 R10: 000000000000000a R11: 0000000000000207 R12: 0000000001a048a0 R13: 0000000000000000 R14: 000000000009880b R15: 00007ffe66512c48 rcu_sched kthread starved for 125589 jiffies! g5317 c5316 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0 RCU grace-period kthread stack dump: rcu_sched R running task 23896 9 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2848 [inline] __schedule+0x801/0x1e30 kernel/sched/core.c:3490 schedule+0xef/0x430 kernel/sched/core.c:3549 schedule_timeout+0x138/0x240 kernel/time/timer.c:1801 rcu_gp_kthread+0x6b5/0x1940 kernel/rcu/tree.c:2231 kthread+0x345/0x410 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411 --- This bug is generated by a dumb bot. 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