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=-5.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,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 0F1B6C388F7 for ; Wed, 28 Oct 2020 17:58:02 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7BB19247F9 for ; Wed, 28 Oct 2020 17:58:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="bybyyh6d"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="ACb0CdvI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7BB19247F9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=fX2JxYrT5CO21Y0SciQ0UqUYP379T2u01IBV5h8Mtjk=; b=bybyyh6dFU8j/emTmE0gOoXfu /tOUN7DSvYQf4PF3MhXopjAaYprz4SBCWVJTMJgvnvJnVtoLmvY2AYiivNiL2ubElWZGRdPUa8zVB /MQB6Itj3vL84deZ9cynyrsb+P2siqtNKCNKb7ZTm8sTQCtS0syMpspv2wA1kPy3COb+wobtFC4NK 3QNz8LeDpc/r2/SNqx6hoabhcqqbrY9dy2vcXTsK2LANxOFljyTf+YO+Kjo3Q4nspSU6nOjtVUdoh 20f2YaoEs9jKKNgTZDnB9lPgtEOIK3MQkM27ck97T7wLAadGoaBFZv2j+fDE+j+oAfWTq+fRcJ9f2 F6dg/wREw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kXpgb-0008Qz-9E; Wed, 28 Oct 2020 17:56:37 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kXpgW-0008Q8-4o for linux-arm-kernel@lists.infradead.org; Wed, 28 Oct 2020 17:56:33 +0000 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 19F8F247E8; Wed, 28 Oct 2020 17:56:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603907790; bh=BUO9MvWjdJPjCOnM9UH2ATg0qMpRGrXC5Zt4ZDEkRf0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ACb0CdvIUUblBmVUPGMiWr6mgm8qHPAP3WrJCjQKQGxq3kCfZvFeacyrUqb3vxxNz TAA3+LfC6NL3261t3QBt4eUQ+w4w89A9J5sqEMY+xu/vOszyIK9532gf3BQHqhQEyt /n0jDRvjjwDDXMS85FeBU2zfhhr3KoiKuAZQEQ5I= Date: Wed, 28 Oct 2020 17:56:25 +0000 From: Will Deacon To: Dmitry Vyukov Subject: Re: Does LOCKDEP work on ARM64? Message-ID: <20201028175625.GA29206@willie-the-truck> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201028_135632_305473_E4684F5D X-CRM114-Status: GOOD ( 16.88 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Peter Zijlstra , Catalin Marinas , LKML , Ingo Molnar , syzkaller , Linux ARM Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sat, Oct 24, 2020 at 11:51:49AM +0200, Dmitry Vyukov wrote: > Hello ARM64/LOCKDEP maintainers, > > I've started experimenting with running syzkaller on ARM64 using > QEMU/TCG. Total execution speed is very low and it ran just a handful > of tests, but I am seeing massive amounts of locking bugs. Most of > these were not observed on x86_64, while x86_64 ran gazillions of > tests by now and most of these are trivial to trigger (depend only on > call stack) and they do not look ARM64-specific. So I wonder: > 1. Are there any known issues with LOCKDEP on ARM64? > 2. Or are all these real and it's x86_64 LOCKDEP that's misbehaving? > 3. Or are both x86_64 and ARM64 fine and these are just somehow ARM64-specific? > > Here are details. Kernel is on > f9893351acaecf0a414baf9942b48d5bb5c688c6 (recent upstream HEAD). > Kernel config: > https://gist.githubusercontent.com/dvyukov/c92a1e08f3f7e22b1f0387096d98b18b/raw/9f79f83c3b018ac27a040649f7d0fef36b63b960/gistfile1.txt > > Here is one "Invalid wait context". It looks like just a put_user > inside of syscall function: > https://gist.githubusercontent.com/dvyukov/15639a949278a981c8eb125b3088a6b8/raw/286117bc292578c07c8afbf0fa563cd5528821e7/gistfile1.txt > > Here is one "bad unlock balance detected". The looks well balanced and > the code path is well exercised: > https://gist.githubusercontent.com/dvyukov/805f867823b9f77a26c2ebedec5b9b9e/raw/2e6605fb5c90f56ebd1ccda78d613b5c219dfb82/gistfile1.txt > > Here is one "workqueue leaked lock". Again, lock/unlock are very local > and there is no control flow in between: > https://gist.githubusercontent.com/dvyukov/4d18d35a79d7e74bf66d6e7ec3794ec0/raw/1ff3e2a5d3a825eb0d196af1f81c67a47fa3a2f6/gistfile1.txt > > Here is one confusing "bad unlock balance detected": > https://gist.githubusercontent.com/dvyukov/e222fa34e04104678c52a5b5b1ad15a3/raw/943c6ebbc022418b89fa63b6282fa1f1f40a276a/gistfile1.txt > > Here is one confusing "suspicious RCU usage": > https://gist.githubusercontent.com/dvyukov/77b0ec246e1db86e549a80e4a11ec218/raw/0bce97be186c0a6617d8835a694443ed1aa2a98a/gistfile1.txt > > Overall I have more than 50 of these now. I'm not aware of any lockdep issues specific to arm64. Mark -- do any of these look familiar to you when you run syzkaller on real hardware? Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel