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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 70F40C46460 for ; Mon, 13 Aug 2018 03:05:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 133AE21785 for ; Mon, 13 Aug 2018 03:05:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="AX1ZFHGP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 133AE21785 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727820AbeHMFo1 (ORCPT ); Mon, 13 Aug 2018 01:44:27 -0400 Received: from mail-pf1-f193.google.com ([209.85.210.193]:44675 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725849AbeHMFo1 (ORCPT ); Mon, 13 Aug 2018 01:44:27 -0400 Received: by mail-pf1-f193.google.com with SMTP id k21-v6so7003671pff.11 for ; Sun, 12 Aug 2018 20:04:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=to:cc:from:subject:message-id:date:user-agent:mime-version :content-transfer-encoding:content-language; bh=TwpSUGuGFDFkxibKJ3TSKJ5JM4XI0YwfNEnufeR4F7U=; b=AX1ZFHGPnxX/VWPPAt6m3wEglTTzhI0U012I9GGKa03jbnqNBiNGS+bJRIz82Rajha Ww8V47T+hvkQqGMtVnhbfAEwDlAzziKjHv5g7TMzs5YIyGWCZe9xj/9HH/33YJBMlsQw oCXwx+gIIqD05EzwBAljmo5A1g4x2ZCPRbFgNG1j3QTeK6ELKAiLreGFgJj5v2asXo8R d6195ziXWVtMj0/VSrMrumW8WB70uo3RfJGnOrS/l8eg6ULdrNMVq6Qrhr2rgnMcV5AS 4AjfQQ7uTygxD1vHFzlOwZiOrxcan7fpWlvJyDS7d1MisZI6VtGpy+bZ8cQOnBKIk8w5 zE1Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:cc:from:subject:message-id:date:user-agent :mime-version:content-transfer-encoding:content-language; bh=TwpSUGuGFDFkxibKJ3TSKJ5JM4XI0YwfNEnufeR4F7U=; b=kNXX3Ixy7Iemi6fnASlj0bIRKbfYp4/4PrGrwHnV5I6H4v1blGdS8DgXsyWBCvUyss DO1FmquJVPEyQ0Mg7Ej6vhgvV6itFiSrjD/8wQ80zxROS7X6v9D+2q0p9mTcBvXG6G4n x9qb7WGKS7WN4ss9zoqEYa97YSWO/nA4WGR+uSffR94uHb2GeUksieY/gF7p+SleoSFU 1k4zSqTfEkuCehzJD83V+M/azCAQHbjzQ9Ag/8S7EZ7/EGAXdqzp/1YGgeEubyhlonov 3uBF2+7hWb6DJWrPK/dwPNqQOHsWLWpzdfsSBaZS9togiQJM+qSVahzh+HL6nyRXj8GT ofuA== X-Gm-Message-State: AOUpUlELCTIcbUn9yGGFj1rEDRkES9uhmNj23yt5qen75WFb6W2FtY49 8QkIgY3eDyKw8i0qqBdfLqMq5fll X-Google-Smtp-Source: AA+uWPxqm4kdjIrKIgBi6GD6TrK7PG9U+Q0cTCZt0cAf5IKP928+jXHv4hZpNMh1C45vcRTdowVvuw== X-Received: by 2002:a65:5b8e:: with SMTP id i14-v6mr15497646pgr.242.1534129455254; Sun, 12 Aug 2018 20:04:15 -0700 (PDT) Received: from ?IPv6:2402:f000:1:1501:200:5efe:166.111.71.57? ([2402:f000:1:1501:200:5efe:a66f:4739]) by smtp.gmail.com with ESMTPSA id h130-v6sm56982170pgc.88.2018.08.12.20.04.13 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 12 Aug 2018 20:04:14 -0700 (PDT) To: dave@stgolabs.net, paulmck@linux.vnet.ibm.com, josh@joshtriplett.org, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com Cc: Linux Kernel Mailing List From: Jia-Ju Bai Subject: [BUG] kernel: rcu: a possible sleep-in-atomic-context bug in srcu_read_delay() Message-ID: <4179b4d2-b832-abcd-d407-b865765f28d6@gmail.com> Date: Mon, 13 Aug 2018 11:04:10 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The kernel may sleep with holding a spinlock. The function call paths (from bottom to top) in Linux-4.16 are: [FUNC] schedule_timeout_interruptible kernel/rcu/rcutorture.c, 523: schedule_timeout_interruptible in srcu_read_delay kernel/rcu/rcutorture.c, 1105: [FUNC_PTR]srcu_read_delay in rcu_torture_timer kernel/rcu/rcutorture.c, 1104: spin_lock in rcu_torture_timer Note that [FUNC_PTR] means a function pointer call is used. I do not find a good way to fix, so I only report. This is found by my static analysis tool (DSAC). Thanks, Jia-Ju Bai