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=-10.4 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 AD33AC4338F for ; Wed, 4 Aug 2021 06:29:07 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 B23DA60F56 for ; Wed, 4 Aug 2021 06:29:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org B23DA60F56 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=csgroup.eu Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4Gfhf66jxvz3cX6 for ; Wed, 4 Aug 2021 16:29:02 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=csgroup.eu (client-ip=93.17.235.10; helo=pegase2.c-s.fr; envelope-from=christophe.leroy@csgroup.eu; receiver=) Received: from pegase2.c-s.fr (pegase2.c-s.fr [93.17.235.10]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Gfhdj5DB6z30CZ for ; Wed, 4 Aug 2021 16:28:39 +1000 (AEST) Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4Gfhdb3xn1z9sWH; Wed, 4 Aug 2021 08:28:35 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase2.c-s.fr ([172.26.127.65]) by localhost (pegase2.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 8NdM5a1txM0b; Wed, 4 Aug 2021 08:28:35 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase2.c-s.fr (Postfix) with ESMTP id 4Gfhdb2y2zz9sWG; Wed, 4 Aug 2021 08:28:35 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 461CB8B79A; Wed, 4 Aug 2021 08:28:35 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id 4YJr5MCJhASt; Wed, 4 Aug 2021 08:28:35 +0200 (CEST) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id E778D8B764; Wed, 4 Aug 2021 08:28:34 +0200 (CEST) Subject: Re: Debian SID kernel doesn't boot on PowerBook 3400c To: Finn Thain References: <60841a75-ed7c-8789-15db-272bf43055f5.ref@yahoo.com> <60841a75-ed7c-8789-15db-272bf43055f5@yahoo.com> <20210731175842.Horde.UunWM8rZMP0dRCaeWUo-og1@messagerie.c-s.fr>

From: Christophe Leroy Message-ID: Date: Wed, 4 Aug 2021 08:28:34 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Debian PowerPC , linuxppc-dev@lists.ozlabs.org, Stan Johnson Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Le 04/08/2021 à 02:34, Finn Thain a écrit : > > On Tue, 3 Aug 2021, Christophe Leroy wrote: > >> >> Looks like the memory errors are linked to KUAP (Kernel Userspace Access >> Protection). Based on the places the problems happen, I don't think >> there are any invalid access, so there must be something wrong in the >> KUAP logic, probably linked to some interrupts happenning in kernel mode >> while the KUAP window is opened. And because is not selected by default >> on book3s/32 until 5.14, probably nobody ever tested it in a real >> environment before you. >> >> I think the issue may be linked to commit >> https://github.com/linuxppc/linux/commit/c16728835 which happened >> between 5.12 and 5.13. > > The messages, "Kernel attempted to write user page (c6207c) - exploit > attempt? (uid: 0)", appear in the console logs generated by v5.13. Those > logs come from the Powerbook G3 discussion in the other thread. Could that > be the same bug? > Yes, most likely. So you confirm this appears with 5.13 and not 5.12 ? Can you check if they happen at commit c16728835 Can you check if they DO NOT happen at preceding commit c16728835~ Could you test without CONFIG_PPC_KUAP Could you test with CONFIG_PPC_KUAP and CONFIG_PPC_KUAP_DEBUG Thanks Christophe