Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EC025C433F5 for ; Wed, 22 Dec 2021 17:33:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344369AbhLVRd1 (ORCPT ); Wed, 22 Dec 2021 12:33:27 -0500 Received: from mail-il1-f197.google.com ([209.85.166.197]:54797 "EHLO mail-il1-f197.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232852AbhLVRd0 (ORCPT ); Wed, 22 Dec 2021 12:33:26 -0500 Received: by mail-il1-f197.google.com with SMTP id g14-20020a92c7ce000000b002b1e78da1f9so1658362ilk.21 for ; Wed, 22 Dec 2021 09:33:26 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:date:message-id:subject:from:to; bh=bEbdWmUFAsr/tvwx1s231eqfR4JsDg+TU1S7GLvjmuM=; b=Jq2li+yGU+D8o0nLYXgx8Vv0mVpx1C/YZaEea9cPX10kOgNIQPf7W+ywzr2jSUdT54 b7r2Yp2ZTezONXumvlLshxwiqLV5C9gzZlIRy2sbBAyFx0oiP0zM4pShjNhE6dI/YQ7x oqQJqGXaLgNF7o88DrryqYfCSNasuGpN9GRTnUfmgyjqadqR2jiir//prVy32conqeLg G6ZXNLGxt13xFH0S9o0KVuFIhw7n8YLsRGDfmzzoI1tis0C9E5Skf3CONSTqosDWcvNh eIdGWuU/bxgsW6qL2N+w3GR6YX9Seq0hQc60tUWdbXOxInbMw70YVSguTJFjhhltjgE6 zucg== X-Gm-Message-State: AOAM531q1mgKIbe/VC8771K7oh9N1n8EkQAWCE7433gmPD+7JGx+Xixq 3ZKU8Ac7OgLvAml2ZsyPiXzHLYe5OM4E4KFtWzgWGUaL1WTW X-Google-Smtp-Source: ABdhPJyYBiS5x4l3gZVXhYpVRV8hsZ20+LzUWD5jeiI1BvDACkJEmO0Es+DquPVuHpzU77a9fjRcOGK7d92ugqKUVFmAHj0BMLZB MIME-Version: 1.0 X-Received: by 2002:a02:a306:: with SMTP id q6mr2126689jai.319.1640194406057; Wed, 22 Dec 2021 09:33:26 -0800 (PST) Date: Wed, 22 Dec 2021 09:33:26 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000ef8cbb05d3bf84cd@google.com> Subject: [syzbot] INFO: rcu detected stall in ext4_file_write_iter (4) From: syzbot To: fweisbec@gmail.com, linux-kernel@vger.kernel.org, mingo@kernel.org, syzkaller-bugs@googlegroups.com, tglx@linutronix.de Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, syzbot found the following issue on: HEAD commit: 9eaa88c7036e Merge tag 'libata-5.16-rc6' of git://git.kern.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=142d4143b00000 kernel config: https://syzkaller.appspot.com/x/.config?x=e3bdfd29b408d1b6 dashboard link: https://syzkaller.appspot.com/bug?extid=03464269af631f4a4bdf compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11b1537db00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=125de549b00000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+03464269af631f4a4bdf@syzkaller.appspotmail.com rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=5509, q=170) rcu: All QSes seen, last rcu_preempt kthread activity 8642 (4295000735-4294992093), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 8643 jiffies! g5509 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:28208 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4972 [inline] context_switch kernel/sched/core.c:4972 [inline] kernel/sched/core.c:6253 __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 kernel/sched/core.c:6326 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 kernel/rcu/tree.c:2128 kthread+0x405/0x4f0 kernel/kthread.c:327 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 0 CPU: 0 PID: 3672 Comm: syz-executor549 Not tainted 5.16.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] __dump_stack lib/dump_stack.c:88 [inline] lib/dump_stack.c:106 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] kernel/rcu/tree_stall.h:481 rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:481 kernel/rcu/tree_stall.h:481 print_other_cpu_stall kernel/rcu/tree_stall.h:586 [inline] check_cpu_stall kernel/rcu/tree_stall.h:729 [inline] rcu_pending kernel/rcu/tree.c:3878 [inline] print_other_cpu_stall kernel/rcu/tree_stall.h:586 [inline] kernel/rcu/tree.c:2597 check_cpu_stall kernel/rcu/tree_stall.h:729 [inline] kernel/rcu/tree.c:2597 rcu_pending kernel/rcu/tree.c:3878 [inline] kernel/rcu/tree.c:2597 rcu_sched_clock_irq+0x2125/0x2200 kernel/rcu/tree.c:2597 kernel/rcu/tree.c:2597 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428 kernel/time/tick-sched.c:1428 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __run_hrtimer kernel/time/hrtimer.c:1685 [inline] kernel/time/hrtimer.c:1749 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] arch/x86/kernel/apic/apic.c:1103 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 arch/x86/include/asm/idtentry.h:638 RIP: 0010:owner_on_cpu kernel/locking/rwsem.c:667 [inline] RIP: 0010:owner_on_cpu kernel/locking/rwsem.c:667 [inline] kernel/locking/rwsem.c:750 RIP: 0010:rwsem_spin_on_owner+0x1aa/0x290 kernel/locking/rwsem.c:750 kernel/locking/rwsem.c:750 Code: a8 08 75 33 49 8d 7c 24 34 48 89 f8 48 c1 e8 03 42 0f b6 14 28 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 b0 00 00 00 <41> 8b 44 24 34 85 c0 0f 85 14 ff ff ff b8 08 00 00 00 48 83 c4 08 RSP: 0018:ffffc90002817448 EFLAGS: 00000246 RAX: 0000000000000007 RBX: ffff88806da34680 RCX: ffffffff815a9743 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88807d2000b4 RBP: ffff88806da34688 R08: 0000000000000000 R09: ffff888078b322c7 R10: ffffed100f166458 R11: 0000000000000001 R12: ffff88807d200080 R13: dffffc0000000000 R14: ffff888078b322c0 R15: ffffed100f166458 rwsem_optimistic_spin kernel/locking/rwsem.c:808 [inline] rwsem_optimistic_spin kernel/locking/rwsem.c:808 [inline] kernel/locking/rwsem.c:1068 rwsem_down_write_slowpath+0x1a8/0x1110 kernel/locking/rwsem.c:1068 kernel/locking/rwsem.c:1068 __down_write_common kernel/locking/rwsem.c:1268 [inline] __down_write_common kernel/locking/rwsem.c:1265 [inline] __down_write kernel/locking/rwsem.c:1277 [inline] __down_write_common kernel/locking/rwsem.c:1268 [inline] kernel/locking/rwsem.c:1524 __down_write_common kernel/locking/rwsem.c:1265 [inline] kernel/locking/rwsem.c:1524 __down_write kernel/locking/rwsem.c:1277 [inline] kernel/locking/rwsem.c:1524 down_write+0x135/0x150 kernel/locking/rwsem.c:1524 kernel/locking/rwsem.c:1524 inode_lock include/linux/fs.h:783 [inline] inode_lock include/linux/fs.h:783 [inline] fs/ext4/file.c:263 ext4_buffered_write_iter+0xb6/0x3b0 fs/ext4/file.c:263 fs/ext4/file.c:263 ext4_file_write_iter+0x423/0x14e0 fs/ext4/file.c:681 fs/ext4/file.c:681 call_write_iter include/linux/fs.h:2162 [inline] call_write_iter include/linux/fs.h:2162 [inline] fs/read_write.c:725 do_iter_readv_writev+0x472/0x750 fs/read_write.c:725 fs/read_write.c:725 do_iter_write+0x188/0x710 fs/read_write.c:851 fs/read_write.c:851 vfs_iter_write+0x70/0xa0 fs/read_write.c:892 fs/read_write.c:892 iter_file_splice_write+0x6fa/0xc10 fs/splice.c:689 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] do_splice_from fs/splice.c:767 [inline] fs/splice.c:936 direct_splice_actor+0x110/0x180 fs/splice.c:936 fs/splice.c:936 splice_direct_to_actor+0x34b/0x8c0 fs/splice.c:891 fs/splice.c:891 do_splice_direct+0x1b3/0x280 fs/splice.c:979 fs/splice.c:979 do_sendfile+0xaf2/0x1250 fs/read_write.c:1245 fs/read_write.c:1245 __do_sys_sendfile64 fs/read_write.c:1310 [inline] __se_sys_sendfile64 fs/read_write.c:1296 [inline] __do_sys_sendfile64 fs/read_write.c:1310 [inline] fs/read_write.c:1296 __se_sys_sendfile64 fs/read_write.c:1296 [inline] fs/read_write.c:1296 __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1296 fs/read_write.c:1296 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_x64 arch/x86/entry/common.c:50 [inline] arch/x86/entry/common.c:80 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f34d1e3f169 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc49095728 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007f34d1e3f169 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000004 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000076d4d R13: 00007ffc4909573c R14: 00007ffc49095750 R15: 00007ffc49095740 ---------------- Code disassembly (best guess): 0: a8 08 test $0x8,%al 2: 75 33 jne 0x37 4: 49 8d 7c 24 34 lea 0x34(%r12),%rdi 9: 48 89 f8 mov %rdi,%rax c: 48 c1 e8 03 shr $0x3,%rax 10: 42 0f b6 14 28 movzbl (%rax,%r13,1),%edx 15: 48 89 f8 mov %rdi,%rax 18: 83 e0 07 and $0x7,%eax 1b: 83 c0 03 add $0x3,%eax 1e: 38 d0 cmp %dl,%al 20: 7c 08 jl 0x2a 22: 84 d2 test %dl,%dl 24: 0f 85 b0 00 00 00 jne 0xda * 2a: 41 8b 44 24 34 mov 0x34(%r12),%eax <-- trapping instruction 2f: 85 c0 test %eax,%eax 31: 0f 85 14 ff ff ff jne 0xffffff4b 37: b8 08 00 00 00 mov $0x8,%eax 3c: 48 83 c4 08 add $0x8,%rsp ---------------- Code disassembly (best guess): 0: a8 08 test $0x8,%al 2: 75 33 jne 0x37 4: 49 8d 7c 24 34 lea 0x34(%r12),%rdi 9: 48 89 f8 mov %rdi,%rax c: 48 c1 e8 03 shr $0x3,%rax 10: 42 0f b6 14 28 movzbl (%rax,%r13,1),%edx 15: 48 89 f8 mov %rdi,%rax 18: 83 e0 07 and $0x7,%eax 1b: 83 c0 03 add $0x3,%eax 1e: 38 d0 cmp %dl,%al 20: 7c 08 jl 0x2a 22: 84 d2 test %dl,%dl 24: 0f 85 b0 00 00 00 jne 0xda * 2a: 41 8b 44 24 34 mov 0x34(%r12),%eax <-- trapping instruction 2f: 85 c0 test %eax,%eax 31: 0f 85 14 ff ff ff jne 0xffffff4b 37: b8 08 00 00 00 mov $0x8,%eax 3c: 48 83 c4 08 add $0x8,%rsp --- 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. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches