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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 53D74C0015E for ; Sat, 12 Aug 2023 14:02:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231874AbjHLOCR (ORCPT ); Sat, 12 Aug 2023 10:02:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49450 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231479AbjHLOCQ (ORCPT ); Sat, 12 Aug 2023 10:02:16 -0400 Received: from mout.gmx.net (mout.gmx.net [212.227.15.15]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF82D198B; Sat, 12 Aug 2023 07:02:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.de; s=s31663417; t=1691848930; x=1692453730; i=deller@gmx.de; bh=AeSNKvyEnVBzyAV9VKdJ3kwSqc+TTxTkUDwOevXtomQ=; h=X-UI-Sender-Class:Date:Subject:From:To:Cc:References:In-Reply-To; b=s4PEtfYcBS6SI68lpLAq85GfaoEwbXqXeMYlbtLmDYm3qn7SNNgfCG7ukd6Xa1muRL5dISV gsRQC1XSUMlpvrnCjyT8DZOSEAhTA+h9FAVmNcx8LORU+00/1UEwknXL6X7MSgZmAgD8aBJhg wJOsfj6yYn0gUUM456UYZ1laCtlsbcdrutdt8DOG3jRxxWKpyauCOrWkGIlr64d+J4ObCtut7 YZAx6LnRxtn9xo5HNwLiW9ikBpiq01Zgu6J0d7bLDGbWobbCwRat4bxR/9DbSQT28dIA1DXaz s9QeERhSNP6jGFweOz60axD1IyCawYIQbij2GAR6R03CAHSnJXBA== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from [192.168.20.60] ([94.134.153.44]) by mail.gmx.net (mrgmx005 [212.227.17.190]) with ESMTPSA (Nemesis) id 1MZTqW-1qG4G42aOc-00WW9C; Sat, 12 Aug 2023 16:02:10 +0200 Message-ID: <1210dbf6-8bfe-9ea5-ba31-77c99e170817@gmx.de> Date: Sat, 12 Aug 2023 16:02:10 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH] init: Add lockdep annotation to kthreadd_done completer Content-Language: en-US From: Helge Deller To: Andrew Morton , Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, linux-parisc@vger.kernel.org, Mike Rapoport References: <20230811094359.ae44c1081b52f69baad8e651@linux-foundation.org> <180865b8-cba9-5676-ca7f-0865005f8af5@gmx.de> In-Reply-To: <180865b8-cba9-5676-ca7f-0865005f8af5@gmx.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:FZ66bV7hRgLmWiA4BxA/MZuuqGqx5CejM8Sq4eeQZfjZrRenAct hDw/WhVLhvJw+UEDCWMoT8xatoyaluwuNbkWbhdlAy/dsGmSzsduekmquiAb5KVLrJ9Ksal HtVPoy8MYU8lwncburHlV3VrTTdM9vmrdSLuOJKGLSBXJR2qCJu5/BSZfiIcNL4MMBRqVvD q/IMKDmZE+qih3j9PQRJg== UI-OutboundReport: notjunk:1;M01:P0:ydNhk0s+2Hc=;Fx7ZQII5phYAWhJH28MjwsYuMsL DVRM3Qft+h/UexPXpqKcmT9iOQryAKP0rJ8UAU597aJJFPkcph4ChUkMJOdnO21l3nj39umUn ao53v12e5w+6/WM/G5lXzjLHnZIS+mqGMVy79nY7F1g+bQMAKWl5P3VbfWnhvnH4mK7I2VdPs ycIsSm+ZURUnBP5KK0i8ytbiK0FuoCO8SFO2KyB7lpv72COeAhbABB1FdT9KEJe7ByfW3Wr1r YjP4Sqmu/fbfgOmBncuSSENT1NEKoYqZZbbzrTPciJIp6AO5FQjgTJgNW+nrGTDjb2NZH6ZdP dbr/JD1BbQKg8ONG0fes4BMopjnJjWQUN/1jGl/FApJXOtobW2NjHF+d9DuH3Q4sPQmVivy3b JTdlgZzhhR3ogx5aOaSSZO/MpQB1I4RpUQmSlfz7xVC20zLzMD8ASMAI8hYRRiJB5De+3of2P U4bNS8nff1LfBXvGP0jLwsvmKKtz5iKDvTnfH2UcV4da/qIFXkD0pxNY+kFP+sBh+V8gp/Ah9 lsz3fxWyWphf8lcUJr2gtCw28Z7b913a1KIeV/I/yLUoEOY8Pa9nUGFmzaYCmYluVo1y6Bchh SXtO3ZdXTt6TspsMTdJXHNc8cVLOJSMnVoUV58OeLhtYaViqGeboBIKX6Y2o+N9W9ojMmOPry 7/N1F2hRTXPX5Y0yygJ0uZ0SzOOzFJzB6a6CLrz/nrH4yWIouJ0ztCbZigHBFiUNsZjkn8fvg yE2s9GfS529NqypKyi2K75qO6rRugJxjJA8ZQ6ZoTQUdHhQX/21FbOHGkwZM9+oWFt7U3QN48 bdoTenpKUc9Kz78fErvs1PevNAB6On4rHPO2/D9wxdytKYa5abNeeWSULkCEGuRiu2jn7xrSF 4F/WAZ8mhgIfAfH+Za1gdATthywrrv6hhb0bEbaAEYq1cPryTOep44zxTZtcmjKqwFfkXhzTp r//2rtsbHs9D1SueFV0q/rCGtHk= Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org Hi Andrew, On 8/11/23 19:44, Helge Deller wrote: > On 8/11/23 18:43, Andrew Morton wrote: >> On Fri, 11 Aug 2023 18:04:22 +0200 Helge Deller wrote: >> >>> Add the missing lockdep annotation to avoid this warning: >>> >>> =C2=A0 INFO: trying to register non-static key. >>> =C2=A0 The code is fine but needs lockdep annotation, or maybe >>> =C2=A0 you didn't initialize this object before use? >>> =C2=A0 turning off the locking correctness validator. >>> =C2=A0 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.5.0-rc5+ #681 >>> =C2=A0 Hardware name: 9000/785/C3700 >>> =C2=A0 Backtrace: >>> =C2=A0=C2=A0 [<000000004030bcd0>] show_stack+0x74/0xb0 >>> =C2=A0=C2=A0 [<0000000041469c7c>] dump_stack_lvl+0x104/0x180 >>> =C2=A0=C2=A0 [<0000000041469d2c>] dump_stack+0x34/0x48 >>> =C2=A0=C2=A0 [<000000004040e5b4>] register_lock_class+0xd24/0xd30 >>> =C2=A0=C2=A0 [<000000004040c21c>] __lock_acquire.isra.0+0xb4/0xac8 >>> =C2=A0=C2=A0 [<000000004040cd60>] lock_acquire+0x130/0x298 >>> =C2=A0=C2=A0 [<000000004146df54>] _raw_spin_lock_irq+0x60/0xb8 >>> =C2=A0=C2=A0 [<0000000041472044>] wait_for_completion+0xa0/0x2d0 >>> =C2=A0=C2=A0 [<000000004146b544>] kernel_init+0x48/0x3a8 >>> =C2=A0=C2=A0 [<0000000040302020>] ret_from_kernel_thread+0x20/0x28 >>> >>> ... >>> >>> --- a/init/main.c >>> +++ b/init/main.c >>> @@ -682,6 +682,8 @@ noinline void __ref __noreturn rest_init(void) >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 struct task_struct *tsk; >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 int pid; >>> >>> +=C2=A0=C2=A0=C2=A0 init_completion(&kthreadd_done); >>> + >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 rcu_scheduler_starting(); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 /* >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * We need to spawn init first so = that it obtains pid 1, however >> >> This is pretty old code, as is the page_alloc_init_late() change.=C2=A0= Do >> we know why this warning has just turned up lately? [dropped Helge's assumptions that it's related to parisc's unusual __ARCH_SPIN_LOCK_UNLOCKED_VAL value. It turned out to be wrong. Now I was able to trace down why I see those lockdep warnings on parisc. The short answer is: On parisc the _initdata section lies outside of the usual kernel _stext ... _end range. Lockdep calls static_obj() which currently assumes that __initdata is inside that range and thus returns "false". That's why lockdep then reports INFO: trying to register non-static key. which is wrong. Please drop those 3 lockdep patches from your mm-queue: mm-add-lockdep-annotation-to-pgdat_init_all_done_comp-completer.patch init-add-lockdep-annotation-to-kthreadd_done-completer.patch watchdog-fix-lockdep-warning.patch I'll send one single patch which fixes static_obj() instead. Thanks, Helge