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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 35CD4C433FE for ; Wed, 16 Nov 2022 09:28:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 975656B0071; Wed, 16 Nov 2022 04:28:28 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 925226B0072; Wed, 16 Nov 2022 04:28:28 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7ECDA6B0073; Wed, 16 Nov 2022 04:28:28 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 6EFAE6B0071 for ; Wed, 16 Nov 2022 04:28:28 -0500 (EST) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 2BED5C06EC for ; Wed, 16 Nov 2022 09:28:28 +0000 (UTC) X-FDA: 80138779896.23.1A5EBCD Received: from www262.sakura.ne.jp (www262.sakura.ne.jp [202.181.97.72]) by imf01.hostedemail.com (Postfix) with ESMTP id 6D0F440008 for ; Wed, 16 Nov 2022 09:28:25 +0000 (UTC) Received: from fsav312.sakura.ne.jp (fsav312.sakura.ne.jp [153.120.85.143]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 2AG9RkBP048011; Wed, 16 Nov 2022 18:27:47 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav312.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav312.sakura.ne.jp); Wed, 16 Nov 2022 18:27:46 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav312.sakura.ne.jp) Received: from [192.168.1.9] (M106072142033.v4.enabler.ne.jp [106.72.142.33]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id 2AG9RkVe048008 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NO); Wed, 16 Nov 2022 18:27:46 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Message-ID: <8a3964bd-41fa-5179-1916-565decd11f50@I-love.SAKURA.ne.jp> Date: Wed, 16 Nov 2022 18:27:45 +0900 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.4.2 Subject: Re: [syzbot] INFO: task hung in rfkill_global_led_trigger_worker (2) Content-Language: en-US To: Hillf Danton , syzbot , Greg Kroah-Hartman Cc: Peter Zijlstra , Will Deacon , Waiman Long , Boqun Feng , Dmitry Vyukov , linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com References: <20221116041716.2797-1-hdanton@sina.com> From: Tetsuo Handa In-Reply-To: <20221116041716.2797-1-hdanton@sina.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1668590906; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=pLWUtC/ixweoGIR1Fdal/ZJaC/rB4f51bgA/82Jwtqw=; b=LX3Y0ONfsIQlDKfVneyjYcPUWkcK1DPLKTrjpL2o+qd9xd8csBLia2N5LeKKd8sjrAfGnL yW50km9TYxCvegsAbYYlkhkvsz8pM5Go2IG8cwzdYfqEIMPISuB+joq2GAzOj3wRlcWOXR j3BtvFr9H+YwqRZiTT8MR1pPdGR7fWc= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=none; dmarc=none; spf=none (imf01.hostedemail.com: domain of penguin-kernel@I-love.SAKURA.ne.jp has no SPF policy when checking 202.181.97.72) smtp.mailfrom=penguin-kernel@I-love.SAKURA.ne.jp ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1668590906; a=rsa-sha256; cv=none; b=vsFXqAWjOLEz6wiMQPHBnPJYiidKIIwDpJl3PSXBay4OoW79mszQmkcW/UaYkfhnxdobNF hApDOzVbOmTPQT1rCjVEEp2CeILNIT1OyOKdMxFO9jwBv5cA+ASvWaTkGFOGSHKK06Vp8I 8H52P8ms1gx7aG9ppi1ndqEcHUGBpWc= X-Rspam-User: X-Stat-Signature: d4kb1rrmpg5koqi3pmbcuiwiptrgedmu X-Rspamd-Queue-Id: 6D0F440008 Authentication-Results: imf01.hostedemail.com; dkim=none; dmarc=none; spf=none (imf01.hostedemail.com: domain of penguin-kernel@I-love.SAKURA.ne.jp has no SPF policy when checking 202.181.97.72) smtp.mailfrom=penguin-kernel@I-love.SAKURA.ne.jp X-Rspamd-Server: rspam07 X-HE-Tag: 1668590905-924237 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 2022/11/16 13:17, Hillf Danton wrote: > No deadlock was reported for syz-executor145/4505 and syz-executor145/4516. > Why? Lockdep should be able to report this real deadlock case. But unfortunately, >> INFO: task syz-executor145:4505 blocked for more than 143 seconds. >> Not tainted 6.1.0-rc5-syzkaller-00008-ge01d50cbd6ee #0 >> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. >> task:syz-executor145 state:D stack:21896 pid:4505 ppid:3645 flags:0x00004002 >> >> 2 locks held by syz-executor145/4505: >> #0: ffff88807268e100 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] >> #0: ffff88807268e100 (&dev->mutex){....}-{3:3}, at: nfc_unregister_device+0x87/0x290 net/nfc/core.c:1165 >> #1: ffffffff8e787b08 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_unregister+0xcb/0x220 net/rfkill/core.c:1130 >> >> INFO: task syz-executor145:4516 blocked for more than 144 seconds. >> Not tainted 6.1.0-rc5-syzkaller-00008-ge01d50cbd6ee #0 >> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. >> task:syz-executor145 state:D stack:23096 pid:4516 ppid:3647 flags:0x00004004 >> >> 2 locks held by syz-executor145/4516: >> #0: ffffffff8e787b08 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0x1b3/0x790 net/rfkill/core.c:1278 >> #1: ffff88807268e100 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:835 [inline] >> #1: ffff88807268e100 (&dev->mutex){....}-{3:3}, at: nfc_dev_down+0x33/0x260 net/nfc/core.c:143 device_initialize() hides dev->mutex from lockdep tests; explained at https://groups.google.com/g/syzkaller-bugs/c/Uj9LqEUCwac/m/BhdTjWhNAQAJ .