From patchwork Fri Mar 17 03:13:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Boqun Feng X-Patchwork-Id: 13178477 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 D3235C7619A for ; Fri, 17 Mar 2023 03:15:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229934AbjCQDP0 (ORCPT ); Thu, 16 Mar 2023 23:15:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38152 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229611AbjCQDOJ (ORCPT ); Thu, 16 Mar 2023 23:14:09 -0400 Received: from mail-qt1-x82e.google.com (mail-qt1-x82e.google.com [IPv6:2607:f8b0:4864:20::82e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0BA851CAEF; Thu, 16 Mar 2023 20:13:56 -0700 (PDT) Received: by mail-qt1-x82e.google.com with SMTP id i24so4358126qtm.6; Thu, 16 Mar 2023 20:13:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1679022835; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:feedback-id:from:to:cc:subject :date:message-id:reply-to; bh=0IIu5Yi5LuAls+pJ/ShpvT4cQhYjefLMDzlyAtUzY2M=; b=m+zgzFjXwbdVq8oriwEEmqgtBN1LLiRL+9JjmhytNN0SF3YFVo2Vi8LlvYHglF50VM e2yN/UshjMiKk0Or3cWkHnHYvpWJuHSzPSozs71pP+QjiRkIAX5kxnKEpVhx1aUTcAQg OzOox798eW7VxQdIP313YmzIhXSWFfMrf639rrvvj2AINdeENb899UYdJAoZYtGWV0dg 3hKoIouUO6YjafexNiisB6pdUbhjas6qu7NOk59J9+AzhbuNbR03+U+Ylp368aMWBDk5 DtALnRnFDEdijM30ef1G3R5QF1O11V4QXQlwLn9JOb9TgJ5Liq20bqD9Gl9uea/j1A9P AKpg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679022835; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:feedback-id:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=0IIu5Yi5LuAls+pJ/ShpvT4cQhYjefLMDzlyAtUzY2M=; b=zdfB+IgA7eXAGsTJSTAcqIEnIBcm3jBGKMt8LaJVelyx7T5R4XxSRJjim6qQ0TxANP 70JtDMIPXqV09YGuEJCKLxuvU6CkUqZBp2z3kggA74YoItkLT63sv8TtW2yJtKMfdBjd 5ng0P372z6oD1JX9j5slf2yDBgNiZjd6Hde7Sfef64CMonnztXcb21Cu73A/E0TkCQEB ACqLvVc3AzG2zMFHSnCVACxdrGIwQHyGLy78TXesfbLT5w+tdUkYDExCB+VitSqwk89/ dcxAgifgkHWToee3qXMbP1ZDdXqNIchI01+5kiEbsQIaPCLjS6o2GgTy3vzSTO5jjgRd Lekg== X-Gm-Message-State: AO0yUKVV6CHARZQSLxxUDowN64NLd5bytAuMzcF7vIDlyyaTqnCJqoMJ cbGueXFxbgEoK47LwxhoZ+U= X-Google-Smtp-Source: AK7set/bz+3OIzw1dnNbFrUKZvoDlrzcBSmpVgyEfWc4/E6RcfAUuT7Uvnwt9sz6dLhl52Q8mqt/HQ== X-Received: by 2002:ac8:594f:0:b0:3b9:bc8c:c1fa with SMTP id 15-20020ac8594f000000b003b9bc8cc1famr3055942qtz.5.1679022835153; Thu, 16 Mar 2023 20:13:55 -0700 (PDT) Received: from auth2-smtp.messagingengine.com (auth2-smtp.messagingengine.com. [66.111.4.228]) by smtp.gmail.com with ESMTPSA id p11-20020a05620a22ab00b0074357fa9e15sm829282qkh.42.2023.03.16.20.13.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 16 Mar 2023 20:13:54 -0700 (PDT) Received: from compute2.internal (compute2.nyi.internal [10.202.2.46]) by mailauth.nyi.internal (Postfix) with ESMTP id 345CE27C0054; Thu, 16 Mar 2023 23:13:54 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute2.internal (MEProxy); Thu, 16 Mar 2023 23:13:54 -0400 X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvhedrvdefuddgheejucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhephffvvefufffkofgjfhgggfestdekredtredttdenucfhrhhomhepuehoqhhu nhcuhfgvnhhguceosghoqhhunhdrfhgvnhhgsehgmhgrihhlrdgtohhmqeenucggtffrrg htthgvrhhnpeegleejiedthedvheeggfejveefjeejkefgveffieeujefhueeigfegueeh geeggfenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpe gsohhquhhnodhmvghsmhhtphgruhhthhhpvghrshhonhgrlhhithihqdeiledvgeehtdei gedqudejjeekheehhedvqdgsohhquhhnrdhfvghngheppehgmhgrihhlrdgtohhmsehfih igmhgvrdhnrghmvg X-ME-Proxy: Feedback-ID: iad51458e:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Thu, 16 Mar 2023 23:13:53 -0400 (EDT) From: Boqun Feng To: rcu@vger.kernel.org Cc: Peter Zijlstra , Ingo Molnar , Will Deacon , Waiman Long , Boqun Feng , Lai Jiangshan , "Paul E. McKenney" , Josh Triplett , Steven Rostedt , Mathieu Desnoyers , Davidlohr Bueso , Frederic Weisbecker , Neeraj Upadhyay , Joel Fernandes , Shuah Khan , David Woodhouse , Paolo Bonzini , kvm@vger.kernel.org, seanjc@google.com, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH rcu 5/7] rcutorture: Add SRCU deadlock scenarios Date: Thu, 16 Mar 2023 20:13:37 -0700 Message-Id: <20230317031339.10277-6-boqun.feng@gmail.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230317031339.10277-1-boqun.feng@gmail.com> References: <20230317031339.10277-1-boqun.feng@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: "Paul E. McKenney" In order to test the new SRCU-lockdep functionality, this commit adds an rcutorture.test_srcu_lockdep module parameter that, when non-zero, selects an SRCU deadlock scenario to execute. This parameter is a five-digit number formatted as DNNL, where "D" is 1 to force a deadlock and 0 to avoid doing so; "NN" is the test number, 0 for SRCU-based, 1 for SRCU/mutex-based, and 2 for SRCU/rwsem-based; and "L" is the number of steps in the deadlock cycle. Note that rcutorture.test_srcu_lockdep=1 will also force a hard hang. If a non-zero value of rcutorture.test_srcu_lockdep does not select a deadlock scenario, a console message is printed and testing continues. [ paulmck: Apply kernel test robot feedback, add rwsem support. ] [ paulmck: Apply Dan Carpenter feedback. ] Signed-off-by: Paul E. McKenney Signed-off-by: Boqun Feng --- kernel/rcu/rcutorture.c | 151 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 151 insertions(+) diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 8e6c023212cb..80ff9a743d31 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -120,6 +120,7 @@ torture_param(int, test_boost, 1, "Test RCU prio boost: 0=no, 1=maybe, 2=yes."); torture_param(int, test_boost_duration, 4, "Duration of each boost test, seconds."); torture_param(int, test_boost_interval, 7, "Interval between boost tests, seconds."); torture_param(bool, test_no_idle_hz, true, "Test support for tickless idle CPUs"); +torture_param(int, test_srcu_lockdep, 0, "Test specified SRCU deadlock scenario."); torture_param(int, verbose, 1, "Enable verbose debugging printk()s"); static char *torture_type = "rcu"; @@ -3463,6 +3464,154 @@ static void rcutorture_sync(void) cur_ops->sync(); } +static DEFINE_MUTEX(mut0); +static DEFINE_MUTEX(mut1); +static DEFINE_MUTEX(mut2); +static DEFINE_MUTEX(mut3); +static DEFINE_MUTEX(mut4); +static DEFINE_MUTEX(mut5); +static DEFINE_MUTEX(mut6); +static DEFINE_MUTEX(mut7); +static DEFINE_MUTEX(mut8); +static DEFINE_MUTEX(mut9); + +static DECLARE_RWSEM(rwsem0); +static DECLARE_RWSEM(rwsem1); +static DECLARE_RWSEM(rwsem2); +static DECLARE_RWSEM(rwsem3); +static DECLARE_RWSEM(rwsem4); +static DECLARE_RWSEM(rwsem5); +static DECLARE_RWSEM(rwsem6); +static DECLARE_RWSEM(rwsem7); +static DECLARE_RWSEM(rwsem8); +static DECLARE_RWSEM(rwsem9); + +DEFINE_STATIC_SRCU(srcu0); +DEFINE_STATIC_SRCU(srcu1); +DEFINE_STATIC_SRCU(srcu2); +DEFINE_STATIC_SRCU(srcu3); +DEFINE_STATIC_SRCU(srcu4); +DEFINE_STATIC_SRCU(srcu5); +DEFINE_STATIC_SRCU(srcu6); +DEFINE_STATIC_SRCU(srcu7); +DEFINE_STATIC_SRCU(srcu8); +DEFINE_STATIC_SRCU(srcu9); + +static int srcu_lockdep_next(const char *f, const char *fl, const char *fs, const char *fu, int i, + int cyclelen, int deadlock) +{ + int j = i + 1; + + if (j >= cyclelen) + j = deadlock ? 0 : -1; + if (j >= 0) + pr_info("%s: %s(%d), %s(%d), %s(%d)\n", f, fl, i, fs, j, fu, i); + else + pr_info("%s: %s(%d), %s(%d)\n", f, fl, i, fu, i); + return j; +} + +// Test lockdep on SRCU-based deadlock scenarios. +static void rcu_torture_init_srcu_lockdep(void) +{ + int cyclelen; + int deadlock; + bool err = false; + int i; + int j; + int idx; + struct mutex *muts[] = { &mut0, &mut1, &mut2, &mut3, &mut4, + &mut5, &mut6, &mut7, &mut8, &mut9 }; + struct rw_semaphore *rwsems[] = { &rwsem0, &rwsem1, &rwsem2, &rwsem3, &rwsem4, + &rwsem5, &rwsem6, &rwsem7, &rwsem8, &rwsem9 }; + struct srcu_struct *srcus[] = { &srcu0, &srcu1, &srcu2, &srcu3, &srcu4, + &srcu5, &srcu6, &srcu7, &srcu8, &srcu9 }; + int testtype; + + if (!test_srcu_lockdep) + return; + + deadlock = test_srcu_lockdep / 1000; + testtype = (test_srcu_lockdep / 10) % 100; + cyclelen = test_srcu_lockdep % 10; + WARN_ON_ONCE(ARRAY_SIZE(muts) != ARRAY_SIZE(srcus)); + if (WARN_ONCE(deadlock != !!deadlock, + "%s: test_srcu_lockdep=%d and deadlock digit %d must be zero or one.\n", + __func__, test_srcu_lockdep, deadlock)) + err = true; + if (WARN_ONCE(cyclelen <= 0, + "%s: test_srcu_lockdep=%d and cycle-length digit %d must be greater than zero.\n", + __func__, test_srcu_lockdep, cyclelen)) + err = true; + if (err) + goto err_out; + + if (testtype == 0) { + pr_info("%s: test_srcu_lockdep = %05d: SRCU %d-way %sdeadlock.\n", + __func__, test_srcu_lockdep, cyclelen, deadlock ? "" : "non-"); + if (deadlock && cyclelen == 1) + pr_info("%s: Expect hang.\n", __func__); + for (i = 0; i < cyclelen; i++) { + j = srcu_lockdep_next(__func__, "srcu_read_lock", "synchronize_srcu", + "srcu_read_unlock", i, cyclelen, deadlock); + idx = srcu_read_lock(srcus[i]); + if (j >= 0) + synchronize_srcu(srcus[j]); + srcu_read_unlock(srcus[i], idx); + } + return; + } + + if (testtype == 1) { + pr_info("%s: test_srcu_lockdep = %05d: SRCU/mutex %d-way %sdeadlock.\n", + __func__, test_srcu_lockdep, cyclelen, deadlock ? "" : "non-"); + for (i = 0; i < cyclelen; i++) { + pr_info("%s: srcu_read_lock(%d), mutex_lock(%d), mutex_unlock(%d), srcu_read_unlock(%d)\n", + __func__, i, i, i, i); + idx = srcu_read_lock(srcus[i]); + mutex_lock(muts[i]); + mutex_unlock(muts[i]); + srcu_read_unlock(srcus[i], idx); + + j = srcu_lockdep_next(__func__, "mutex_lock", "synchronize_srcu", + "mutex_unlock", i, cyclelen, deadlock); + mutex_lock(muts[i]); + if (j >= 0) + synchronize_srcu(srcus[j]); + mutex_unlock(muts[i]); + } + return; + } + + if (testtype == 2) { + pr_info("%s: test_srcu_lockdep = %05d: SRCU/rwsem %d-way %sdeadlock.\n", + __func__, test_srcu_lockdep, cyclelen, deadlock ? "" : "non-"); + for (i = 0; i < cyclelen; i++) { + pr_info("%s: srcu_read_lock(%d), down_read(%d), up_read(%d), srcu_read_unlock(%d)\n", + __func__, i, i, i, i); + idx = srcu_read_lock(srcus[i]); + down_read(rwsems[i]); + up_read(rwsems[i]); + srcu_read_unlock(srcus[i], idx); + + j = srcu_lockdep_next(__func__, "down_write", "synchronize_srcu", + "up_write", i, cyclelen, deadlock); + down_write(rwsems[i]); + if (j >= 0) + synchronize_srcu(srcus[j]); + up_write(rwsems[i]); + } + return; + } + +err_out: + pr_info("%s: test_srcu_lockdep = %05d does nothing.\n", __func__, test_srcu_lockdep); + pr_info("%s: test_srcu_lockdep = DNNL.\n", __func__); + pr_info("%s: D: Deadlock if nonzero.\n", __func__); + pr_info("%s: NN: Test number, 0=SRCU, 1=SRCU/mutex, 2=SRCU/rwsem.\n", __func__); + pr_info("%s: L: Cycle length.\n", __func__); +} + static int __init rcu_torture_init(void) { @@ -3504,6 +3653,8 @@ rcu_torture_init(void) if (cur_ops->init) cur_ops->init(); + rcu_torture_init_srcu_lockdep(); + if (nreaders >= 0) { nrealreaders = nreaders; } else {