From mboxrd@z Thu Jan 1 00:00:00 1970 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3144FC433F5 for ; Mon, 27 Sep 2021 02:58:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0435F6054E for ; Mon, 27 Sep 2021 02:58:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232473AbhI0Czq (ORCPT ); Sun, 26 Sep 2021 22:55:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41528 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229572AbhI0Czp (ORCPT ); Sun, 26 Sep 2021 22:55:45 -0400 Received: from mail-pl1-x636.google.com (mail-pl1-x636.google.com [IPv6:2607:f8b0:4864:20::636]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 58935C061570 for ; Sun, 26 Sep 2021 19:54:08 -0700 (PDT) Received: by mail-pl1-x636.google.com with SMTP id j14so10770349plx.4 for ; Sun, 26 Sep 2021 19:54:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qcraft-ai.20210112.gappssmtp.com; s=20210112; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-transfer-encoding:content-language; bh=FhHLiSp0N8Y7r7RjQO2xWk4EbjynVzAJss09GhCE63o=; b=aj0q8v1Om+Zj5+ltt8snO4Ce29Cm7X7jwIDjHIdJD3ofMf06Awyz2hLCg6MHu6tlMH S8INX+6tLmwtL+/zosIHmzSCt41PJMUxAQ8Ps3+g1ZHxWtKiDFUeeGXs5JaUjo5Yn+nL fHlkIXZyqWLF8/kCdzsE64GiN4y5MJnJvJfZH0T2W1ZrCXTXs4Ao2dxA4ev/6whrH9fY nPBtbBFqAPdJXayNlfBYcIXhQycA44ny5ommO3SwQoM5sJdYfmvTfestS8OfsbtNNq5m FjvGfvBhi+afCphkWtMyINypkwelPJ2yDYyeECRA8FIgdBuV8HxOw/txkLlsdIrYwwY9 hjiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=FhHLiSp0N8Y7r7RjQO2xWk4EbjynVzAJss09GhCE63o=; b=634Tp09UK4aCVW5FjcMwph9pbfnOYIns//T1Hd4OPF25IB5dGy5Nh8BL9Pl5dIpqsv WGiPaa3SCQXbcmt+gLWcdy3wlHhLMYx4snfPLoqJzJ3MIPaj78lJXRYfznFBXHJT4met 2F6kKpCQugU06TnjHD5/CKdt7g9bJfQNPFe8TdX9w/bnxEmsLNa/EVEcSrq/7dhpPida veearCdig3F7tg+rj7aR/I2Y4qnwzmKxsMu9NvuywiV06adz1YwkgRxOI0xNw05nWvpc ajp+658WJHbCHdz800InNn6EyczAwuUW31Rnf2D0kBSY2Cw0m/SI4E6Qts5nZvAIuAwC rtZg== X-Gm-Message-State: AOAM530/h50PK6Zadh4v2V0JqelenNBHieKvw+X7MWDaMSxi3T1NQ8TF Qj30tvGDsN6yY28SOLrW8L/8GA== X-Google-Smtp-Source: ABdhPJwdaVLHpxITiy5QPpf7cquisFoFj4x93Y0M9W+mhm48+9qp8fW+oUp9geP9Og1S6ylXpc8fow== X-Received: by 2002:a17:90a:578e:: with SMTP id g14mr17163365pji.184.1632711247700; Sun, 26 Sep 2021 19:54:07 -0700 (PDT) Received: from [172.18.4.161] ([137.59.101.13]) by smtp.gmail.com with ESMTPSA id s2sm18674232pjs.56.2021.09.26.19.54.03 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 26 Sep 2021 19:54:07 -0700 (PDT) Subject: Re: [syzbot] INFO: rcu detected stall in io_ring_exit_work To: syzbot , bp@alien8.de, hpa@zytor.com, jirislaby@kernel.org, jpoimboe@redhat.com, linux-kernel@vger.kernel.org, mingo@redhat.com, peterz@infradead.org, syzkaller-bugs@googlegroups.com, tglx@linutronix.de, x86@kernel.org, axboe@kernel.dk References: <000000000000d2f3ef05ccc6a52e@google.com> From: zhangqiang Message-ID: <2b6450ae-1861-bdbc-6f65-ca9aedd7aa37@qcraft.ai> Date: Mon, 27 Sep 2021 10:54:01 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <000000000000d2f3ef05ccc6a52e@google.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/9/25 上午8:07, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 5a5d008887b4 Add linux-next specific files for 20210924 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=1094cbf7300000 > kernel config: https://syzkaller.appspot.com/x/.config?x=ae26deb010ccc26f > dashboard link: https://syzkaller.appspot.com/bug?extid=49a58b47c63ba584ff51 > 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=176ffc40b00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11fdcda0b00000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+49a58b47c63ba584ff51@syzkaller.appspotmail.com > > rcu: INFO: rcu_preempt self-detected stall on CPU > rcu: 0-...!: (10499 ticks this GP) idle=76d/1/0x4000000000000000 softirq=9206/9206 fqs=0 > (t=10501 jiffies g=12161 q=535) > rcu: rcu_preempt kthread starved for 10502 jiffies! g12161 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 > 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:28696 pid: 14 ppid: 2 flags:0x00004000 > Call Trace: > > context_switch kernel/sched/core.c:4955 [inline] > __schedule+0x940/0x26f0 kernel/sched/core.c:6236 > schedule+0xd3/0x270 kernel/sched/core.c:6315 > schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 > rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 > rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 > kthread+0x405/0x4f0 kernel/kthread.c:327 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 > > rcu: Stack dump where RCU GP kthread last ran: > Sending NMI from CPU 0 to CPUs 1: > NMI backtrace for cpu 1 > CPU: 1 PID: 6548 Comm: syz-executor027 Not tainted 5.15.0-rc2-next-20210924-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:30 [inline] > RIP: 0010:__orc_find+0x6a/0xf0 arch/x86/kernel/unwind_orc.c:52 > Code: 89 de 49 39 ec 72 4d 4c 89 e0 48 29 e8 48 89 c2 48 c1 e8 3f 48 c1 fa 02 48 01 d0 48 d1 f8 48 8d 5c 85 00 48 89 d8 48 c1 e8 03 <42> 0f b6 14 38 48 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 48 > RSP: 0018:ffffc900020bf510 EFLAGS: 00000a06 > RAX: 1ffffffff1bc00c0 RBX: ffffffff8de00600 RCX: ffffffff89400067 > RDX: 0000000000000007 RSI: ffffffff8e7ffc8a RDI: ffffffff8de005f4 > RBP: ffffffff8de005f4 R08: 0000000000000000 R09: ffffffff8e7ffc8a > R10: fffff52000417ed1 R11: 0000000000086089 R12: ffffffff8de00610 > R13: ffffffff8de005f4 R14: ffffffff8de005f4 R15: dffffc0000000000 > FS: 0000555556c6f300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007fbfeb842140 CR3: 000000017b0ce000 CR4: 00000000001506e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > > orc_find arch/x86/kernel/unwind_orc.c:173 [inline] > unwind_next_frame+0x32a/0x1ce0 arch/x86/kernel/unwind_orc.c:443 > arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 > stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121 > kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 > kasan_set_track mm/kasan/common.c:46 [inline] > set_alloc_info mm/kasan/common.c:434 [inline] > ____kasan_kmalloc mm/kasan/common.c:513 [inline] > ____kasan_kmalloc mm/kasan/common.c:472 [inline] > __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:522 > kmalloc include/linux/slab.h:592 [inline] > io_add_buffers fs/io_uring.c:4423 [inline] > io_provide_buffers fs/io_uring.c:4457 [inline] > io_issue_sqe+0x1d9e/0x7430 fs/io_uring.c:6759 > __io_queue_sqe+0x90/0xb50 fs/io_uring.c:6991 > io_queue_sqe fs/io_uring.c:7042 [inline] > io_submit_sqe fs/io_uring.c:7224 [inline] > io_submit_sqes+0x21be/0x99d0 fs/io_uring.c:7329 > __do_sys_io_uring_enter+0xf55/0x1f00 fs/io_uring.c:9995 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x44/0xae Hi Jens Axboe Does it also trigger RCU stall ? Thanks Qiang > RIP: 0033:0x7fbfeb7d0fb9 > 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:00007ffe945eef88 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa > RAX: ffffffffffffffda RBX: 00000000000d7de4 RCX: 00007fbfeb7d0fb9 > RDX: 0000000000000000 RSI: 00000000000069c1 RDI: 0000000000000003 > RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe945eefac > R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000 > > INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.736 msecs > NMI backtrace for cpu 0 > CPU: 0 PID: 2575 Comm: kworker/u4:6 Not tainted 5.15.0-rc2-next-20210924-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Workqueue: events_unbound io_ring_exit_work > Call Trace: > > __dump_stack lib/dump_stack.c:88 [inline] > dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 > nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 > nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 > trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] > rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343 > print_cpu_stall kernel/rcu/tree_stall.h:627 [inline] > check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] > rcu_pending kernel/rcu/tree.c:3878 [inline] > rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2597 > update_process_times+0x16d/0x200 kernel/time/timer.c:1785 > tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 > tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428 > __run_hrtimer kernel/time/hrtimer.c:1685 [inline] > __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 > hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 > local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] > __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 > sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 > > > asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 > RIP: 0010:unwind_next_frame+0xb7/0x1ce0 arch/x86/kernel/unwind_orc.c:621 > Code: fc ff df 48 c7 04 13 00 00 00 00 48 8b 8c 24 98 00 00 00 65 48 2b 0c 25 28 00 00 00 0f 85 4c 15 00 00 48 81 c4 a0 00 00 00 5b <5d> 41 5c 41 5d 41 5e 41 5f c3 4d 8d 66 48 48 b8 00 00 00 00 00 fc > RSP: 0018:ffffc9000b507710 EFLAGS: 00000282 > RAX: 0000000000000001 RBX: ffffffff81648250 RCX: 0000000000000000 > RDX: dffffc0000000000 RSI: ffffc9000b507f28 RDI: 0000000000000001 > RBP: ffffc9000b507f58 R08: ffffffff8dea4be6 R09: 0000000000000001 > R10: fffff520016a0ef3 R11: 0000000000086089 R12: ffffc9000b500000 > R13: ffffc9000b507775 R14: ffffc9000b507740 R15: ffffc9000b507774 > arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 > stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121 > kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 > kasan_set_track+0x21/0x30 mm/kasan/common.c:46 > kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 > ____kasan_slab_free mm/kasan/common.c:366 [inline] > ____kasan_slab_free mm/kasan/common.c:328 [inline] > __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374 > kasan_slab_free include/linux/kasan.h:230 [inline] > slab_free_hook mm/slub.c:1700 [inline] > slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1726 > slab_free mm/slub.c:3492 [inline] > kfree+0xf6/0x560 mm/slub.c:4538 > __io_remove_buffers fs/io_uring.c:4345 [inline] > __io_remove_buffers fs/io_uring.c:4330 [inline] > io_destroy_buffers fs/io_uring.c:9222 [inline] > io_ring_ctx_free fs/io_uring.c:9279 [inline] > io_ring_exit_work+0xbaa/0x1980 fs/io_uring.c:9460 > process_one_work+0x9b2/0x1690 kernel/workqueue.c:2297 > worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 > kthread+0x405/0x4f0 kernel/kthread.c:327 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 > > ---------------- > Code disassembly (best guess): > 0: 89 de mov %ebx,%esi > 2: 49 39 ec cmp %rbp,%r12 > 5: 72 4d jb 0x54 > 7: 4c 89 e0 mov %r12,%rax > a: 48 29 e8 sub %rbp,%rax > d: 48 89 c2 mov %rax,%rdx > 10: 48 c1 e8 3f shr $0x3f,%rax > 14: 48 c1 fa 02 sar $0x2,%rdx > 18: 48 01 d0 add %rdx,%rax > 1b: 48 d1 f8 sar %rax > 1e: 48 8d 5c 85 00 lea 0x0(%rbp,%rax,4),%rbx > 23: 48 89 d8 mov %rbx,%rax > 26: 48 c1 e8 03 shr $0x3,%rax > * 2a: 42 0f b6 14 38 movzbl (%rax,%r15,1),%edx <-- trapping instruction > 2f: 48 89 d8 mov %rbx,%rax > 32: 83 e0 07 and $0x7,%eax > 35: 83 c0 03 add $0x3,%eax > 38: 38 d0 cmp %dl,%al > 3a: 7c 04 jl 0x40 > 3c: 84 d2 test %dl,%dl > 3e: 75 48 jne 0x88 > > > --- > 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