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 X-Spam-Level: X-Spam-Status: No, score=-4.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 34682C43460 for ; Mon, 3 May 2021 10:45:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 076D1611AD for ; Mon, 3 May 2021 10:45:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233411AbhECKqa (ORCPT ); Mon, 3 May 2021 06:46:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56206 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230246AbhECKq2 (ORCPT ); Mon, 3 May 2021 06:46:28 -0400 Received: from mail-wr1-x431.google.com (mail-wr1-x431.google.com [IPv6:2a00:1450:4864:20::431]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A5BFCC06174A; Mon, 3 May 2021 03:45:34 -0700 (PDT) Received: by mail-wr1-x431.google.com with SMTP id n2so5064231wrm.0; Mon, 03 May 2021 03:45:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=CIFshGooUaaV2myZRcB/yBy/Ci9EHmfy/WmpGw13goE=; b=mip3Qf0U2lZUELW2ocfz6r8j+/8sAYud/ndpff7RbzAX7QhkPPb0636WUFNp/oHTma 7zLIh+s49IjrHp8hQKvvBTPJL4wpTsXBOX62OZ1agy2sR9IIJBacXC4O0VqQ7ReMS+WS 7xXv7mt8O/wbV6qNv4P7WXsJbJ9o30KpBPBzLyU+QD8QPeTP+QmGHBZAser1iPTubpBU 0bmbN05AW/ns/fkBGWbM4/p8puw7Uro7RtRwwAzNVCKeoTsQGnqd6alGKClBxu68iGy4 2ceUUmp2Ta0T/BBSDujFYTJ3LbHm4kzph6CrvKWf5/IephQ8HBRvBPd8XkqZOeY27fk1 J9ZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=CIFshGooUaaV2myZRcB/yBy/Ci9EHmfy/WmpGw13goE=; b=LCmDoyATfVGRYRep358KyDNJrxticXFPpoLxmTJvqzYmzERumgj/knu8+JWLUcFh6k TFmnAUzW8qvvI/NThZq1UeuFZsK3RkzuD3T3ZMIDFLmbwDA+2kdQiFtG/aSlwI55n65j JQWqN3ktckDe+VMkWkfJx5h1+e2Vr/6EArg1S0wr76bzW6i4yq/lI+aVtbTZMTfu1Y0Y DB9XEYNAvLvhnjGBJoWBadGubm2xCBmKgg2AwAXB6x/JNeSpBvJhIMvep3IqnYUH4Cyy WwZWIo4opBC21zp3yDBq+YiBLpcpgJoN02KrRSNkRyOWrIIes0wrWigZqOfDK4heVdEu lmWg== X-Gm-Message-State: AOAM531N8JF7qzE2++BUTNSp0cJUtRK3Nf7m5LaGKJv/amXLQtQ5UfvB XgTL1PoCMuQrs0lpZCpK6h8= X-Google-Smtp-Source: ABdhPJwM/U7znsng8urh2Ji7fU0M55EqgIsxWVGnWn22C7rTr9N8VvO2lAnLmup/ZsvG1v2sxmPwug== X-Received: by 2002:a05:6000:1863:: with SMTP id d3mr8852476wri.126.1620038732261; Mon, 03 May 2021 03:45:32 -0700 (PDT) Received: from [192.168.8.197] ([148.252.132.80]) by smtp.gmail.com with ESMTPSA id p10sm12511600wre.84.2021.05.03.03.45.31 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 03 May 2021 03:45:31 -0700 (PDT) Subject: Re: INFO: task hung in io_uring_cancel_sqpoll To: Palash Oswal Cc: Jens Axboe , io-uring@vger.kernel.org, LKML , syzbot+11bf59db879676f59e52@syzkaller.appspotmail.com References: <0000000000000c97e505bdd1d60e@google.com> <53a22ab4-7a2d-4ebd-802d-9d1b4ce4e087n@googlegroups.com> From: Pavel Begunkov Message-ID: Date: Mon, 3 May 2021 11:45:26 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/3/21 5:41 AM, Palash Oswal wrote: > On Mon, May 3, 2021 at 3:42 AM Pavel Begunkov wrote: >> The test might be very useful. Would you send a patch to >> liburing? Or mind the repro being taken as a test? > > Pavel, > > I'm working on a PR for liburing with this test. Do you know how I can Perfect, thanks > address this behavior? As the hang is sqpoll cancellations, it's most probably fixed in 5.13 + again awaits to be taken for stable. Don't know about segfaults, but it was so for long, and syz reproducers are ofthen faults for me, and exit with 0 in the end. So, I wouldn't worry about it. > root@syzkaller:~/liburing/test# ./runtests.sh sqpoll-cancel-hang > Running test sqp[ 15.310997] Running test sqpoll-cancel-hang: > oll-cancel-hang: > [ 15.333348] sqpoll-cancel-h[305]: segfault at 0 ip 000055ad00e265e3 sp] > [ 15.334940] Code: 89 d8 8d 34 90 8b 45 04 ba 03 00 00 00 c1 e0 04 03 46 > All tests passed > > root@syzkaller:~/liburing/test# ./sqpoll-cancel-hang > [ 13.572639] sqpoll-cancel-h[298]: segfault at 0 ip 00005634c4a455e3 sp] > [ 13.576506] Code: 89 d8 8d 34 90 8b 45 04 ba 03 00 00 00 c1 e0 04 03 46 > [ 23.350459] random: crng init done > [ 23.352837] random: 7 urandom warning(s) missed due to ratelimiting > [ 243.090865] INFO: task iou-sqp-298:299 blocked for more than 120 secon. > [ 243.095187] Not tainted 5.12.0 #142 > [ 243.099800] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disable. > [ 243.105928] task:iou-sqp-298 state:D stack: 0 pid: 299 ppid: 4 > [ 243.111044] Call Trace: > [ 243.112855] __schedule+0xb1d/0x1130 > [ 243.115549] ? __sched_text_start+0x8/0x8 > [ 243.118328] ? io_wq_worker_sleeping+0x145/0x500 > [ 243.121790] schedule+0x131/0x1c0 > [ 243.123698] io_uring_cancel_sqpoll+0x288/0x350 > [ 243.125977] ? io_sq_thread_unpark+0xd0/0xd0 > [ 243.128966] ? mutex_lock+0xbb/0x130 > [ 243.132572] ? init_wait_entry+0xe0/0xe0 > [ 243.135429] ? wait_for_completion_killable_timeout+0x20/0x20 > [ 243.138303] io_sq_thread+0x174c/0x18c0 > [ 243.140162] ? io_rsrc_put_work+0x380/0x380 > [ 243.141613] ? init_wait_entry+0xe0/0xe0 > [ 243.143686] ? _raw_spin_lock_irq+0xa5/0x180 > [ 243.145619] ? _raw_spin_lock_irqsave+0x190/0x190 > [ 243.147671] ? calculate_sigpending+0x6b/0xa0 > [ 243.149036] ? io_rsrc_put_work+0x380/0x380 > [ 243.150694] ret_from_fork+0x22/0x30 > > Palash > -- Pavel Begunkov