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 13E32C433EF for ; Wed, 9 Mar 2022 15:07:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231591AbiCIPIF (ORCPT ); Wed, 9 Mar 2022 10:08:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54556 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229742AbiCIPIE (ORCPT ); Wed, 9 Mar 2022 10:08:04 -0500 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A2CF17EDA3; Wed, 9 Mar 2022 07:07:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=CJjpvJ4D4oTHJIjBPxT3Y89iE6XRNUaLU9GXpNtInfs=; b=H7OaOGWjz19gTjjW4S4SqlPnjc a5h0H3XnKuP2v/h+dtFrdEgwN6wzr7OyrYdu6GA5cvXsD7jhiOiNS9Ul8PC1SMlshTQOpILMLft64 GvTxp/TgNH2Sv/LnYe1t1H51u2cMSp9bb+ZxnquJgWs8NC9RKKnsz4AqtCEQZDaHHPrsx1B3RyIrK KwGdQQuU/0FrDGGzExnbUcqhJS0ETYJKJVwasum8XWSiYeTcUmEhcnRrAi5OFFK6UNGMmjiuj2MxZ E3eqMaXoymwhaNJmPv6ZmGvJcOAdW0m8baVUq3xQFSIgkY2Yy4NtKFOuYTbfU5LF4hFb0rAqG2ofU mNITWItQ==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:57744) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1nRxu0-0001yY-8z; Wed, 09 Mar 2022 15:07:00 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1nRxtw-000828-Uq; Wed, 09 Mar 2022 15:06:56 +0000 Date: Wed, 9 Mar 2022 15:06:56 +0000 From: "Russell King (Oracle)" To: Ard Biesheuvel Cc: Naresh Kamboju , open list , Linux-Next Mailing List , Linux ARM , Linus Walleij , Arnd Bergmann , Corentin Labbe , Stephen Rothwell Subject: Re: [next] arm: Internal error: Oops: 5 PC is at __read_once_word_nocheck Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: Russell King (Oracle) Precedence: bulk List-ID: X-Mailing-List: linux-next@vger.kernel.org On Wed, Mar 09, 2022 at 03:57:32PM +0100, Ard Biesheuvel wrote: > On Wed, 9 Mar 2022 at 15:44, Naresh Kamboju wrote: > > > > On Wed, 9 Mar 2022 at 19:37, Naresh Kamboju wrote: > > > > > > On Wed, 9 Mar 2022 at 16:16, Ard Biesheuvel wrote: > > > > > > > > On Wed, 9 Mar 2022 at 11:37, Russell King (Oracle) > > > > wrote: > > > > > > > > > > On Wed, Mar 09, 2022 at 03:18:12PM +0530, Naresh Kamboju wrote: > > > > > > While boting linux next-20220308 on BeagleBoard-X15 and qemu arm the following > > > > > > kernel crash reported which is CONFIG_KASAN enabled build [1] & [2]. > > > > > > > > > > The unwinder is currently broken in linux-next. Please try reverting > > > > > 532319b9c418 ("ARM: unwind: disregard unwind info before stack frame is > > > > > set up") > > > > I have reverted the suggested commit and built and boot failed due to reported > > kernel crash [1]. > > > > - Naresh > > > > Thanks Naresh, > > This looks like it might be related to the issue Russell just sent a fix for: > https://lore.kernel.org/linux-arm-kernel/CAMj1kXEqp2UmsyUe1eWErtpMk3dGEFZyyno3nqydC_ML0bwTLw@mail.gmail.com/T/#t > > Could you please try that? Well, we unwound until: __irq_svc from migrate_disable+0x0/0x70 and then crashed - and the key thing there is that we're at the start of migrate_disable() when we took an interrupt. For some reason, this triggers an access to address 0x10, which faults. We then try unwinding again, and successfully unwind all the way back to the same point (the line above) which then causes the unwinder to again access address 0x10, and the cycle repeats with the stack growing bigger and bigger. I'd suggest also testing without the revert but with my patch. Thanks. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!