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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 56FC0C47073 for ; Fri, 5 Jan 2024 00:30:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:Subject:References:In-Reply-To:Message-ID:Cc: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=AMhyMtdv7vfgDVMMzdQpRo6XibttV5UhqpDcQLmQbis=; b=BWCJxEyPSvgBXwUUZzr68mUhb9 6ClRE7AbkBk04oUm5QIow5FQG/RPkDDmKcw64WxMuv5xdydeBmS0EFn4MH1NLZ1qLQvPNiOBU/0bW 9KvsA+QpeV6jKlsNEbl8kWzHOFke9WfRsnuzlfAhR6U+qgi4Dlf51W/44L3GyUJzivI7WIhdSCvxJ 9qp/ZVAFj3sUgcb1qNwUEXNDfc1UJarnQlUJMUYMugJWu1yHjM0WPbe+FFL5zBXR9Kh/giNDphHwc 3LPhKR5VBnOAJ1oMLgNiiqtnYd3p4niTvmR4+v4UMAsAIUgGllTT1h4aTe70Oyuqtz9XUJrOTRyhV fwRPv7Fg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rLY6x-00FeOJ-0U; Fri, 05 Jan 2024 00:30:55 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1rLX37-00FUJW-12 for linux-um@bombadil.infradead.org; Thu, 04 Jan 2024 23:22:53 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Transfer-Encoding:Content-Type :MIME-Version:Subject:References:In-Reply-To:Message-ID:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=AMhyMtdv7vfgDVMMzdQpRo6XibttV5UhqpDcQLmQbis=; b=CrBQ8/af2zxcpRkLocH5KoqISv fdhZDs9fjAH6G3t0RTEFD5WM03ygVVeBFefGbjB3bw2+UWx3KUD2XjDitTrzft9cyZnsUxirb10/S kuliud8kHne52fGFlDUEQ9zEqnh1Lth3mcxgoO9qGR145whlqK8T2povK0d2XIoK9+pg0z5rxLyQO tVNx9qxwMmC09yXEjf/z0SqFfXfvNbRwasxVJRJpfCCvvQDsRUGWllQai4SLFdwrc/oF9cxOewgUr D02GG5CdWoYQdVvGkXNZkWD26MPsKIQLwvZS0EnHO1Frt11tv48SN1W1KhahNyOKsaaoUhJgT9Pq6 XRLTsozA==; Received: from lithops.sigma-star.at ([195.201.40.130]) by desiato.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1rLX2v-0069hU-1h for linux-um@lists.infradead.org; Thu, 04 Jan 2024 23:22:43 +0000 Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id DA17D626FAE6; Fri, 5 Jan 2024 00:22:12 +0100 (CET) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id yD_ZKLh5XoAP; Fri, 5 Jan 2024 00:22:11 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id 7780F626FB00; Fri, 5 Jan 2024 00:22:11 +0100 (CET) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id VpwcTByJ0DTB; Fri, 5 Jan 2024 00:22:11 +0100 (CET) Received: from lithops.sigma-star.at (lithops.sigma-star.at [195.201.40.130]) by lithops.sigma-star.at (Postfix) with ESMTP id 550FF626FAE6; Fri, 5 Jan 2024 00:22:11 +0100 (CET) Date: Fri, 5 Jan 2024 00:22:11 +0100 (CET) From: Richard Weinberger To: Petr Tesarik Cc: anton ivanov , Johannes Berg , linux-um , linux-kernel , Roberto Sassu , petr@tesarici.cz, Petr Tesarik Message-ID: <435201914.200552.1704410531143.JavaMail.zimbra@nod.at> In-Reply-To: <20231215121431.680-1-petrtesarik@huaweicloud.com> References: <20231215121431.680-1-petrtesarik@huaweicloud.com> Subject: Re: [PATCH 0/2] um: improve UML page fault handling MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [195.201.40.130] X-Mailer: Zimbra 8.8.12_GA_3807 (ZimbraWebClient - FF97 (Linux)/8.8.12_GA_3809) Thread-Topic: improve UML page fault handling Thread-Index: 3x5bOAmY5/XfwxP9N8Jncq5xgr1IZw== X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240104_232241_757912_D4C83E48 X-CRM114-Status: UNSURE ( 7.17 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org ----- Urspr=C3=BCngliche Mail ----- > Von: "Petr Tesarik" > An: "richard" , "anton ivanov" , "Johannes Berg" > , "linux-um" , "= linux-kernel" > CC: "Roberto Sassu" , petr@tesarici.cz, "P= etr Tesarik" > > Gesendet: Freitag, 15. Dezember 2023 13:14:29 > Betreff: [PATCH 0/2] um: improve UML page fault handling > From: Petr Tesarik >=20 > Improve UML handling of segmentation faults in kernel mode. Although > such page faults are generally caused by a kernel bug, it is annoying > if they cause an infinite loop, or panic the kernel. More importantly, > a robust implementation allows to write KUnit tests for various guard > pages, preventing potential kernel self-protection regressions. >=20 > Petr Tesarik (2): > um: do not panic on kernel mode faults > um: oops on accessing an non-present page in the vmalloc area I think this is a good thing to have. For the implementation side, this needs to use the oops_* helpers from kernel/panic.c and taint the kernel, etc... See arch/x86/kernel/dumpstack.c die() and friends. Thanks, //richard