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=-5.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,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 81B93C433DB for ; Tue, 19 Jan 2021 19:53:25 +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 F047723105 for ; Tue, 19 Jan 2021 19:53:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F047723105 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=armlinux.org.uk 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=Jvgc1RPqx+0NEQ6Httby5S3PbsRYW8iNcOyxc8GsmXc=; b=o5seg5/5bdEqE0W/NlvjDBUiN XUPFVRVyUx1Hhx4fnFOP0tXMOwATrJA5rGi/j6nLmS+Xs89ZJHpfX7cWkBhYPH/XROqDxZzS6Fglm SN8tJAzTGOoTBVM49G+0F8+98f/QeiFKt7emC6EJNW5jNeAlNZpk42TJrWigaSfsJsgQu4JKUK2ll q/wpLKN9tGTjw8VAJckpa/4laxFw5NF5ItmNkoQj9hmQouSSszTHkFVFPvlpPknkt4RmXsZ0d7ny4 LDZlvH3eAGD+O45ooK6zBJJ3p6LHHKny9zhgCnBKH3/SticGPiyvItNLqexEmeNQh6wSvyrB0xh3c d9k75ANHA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l1x2V-0005z8-79; Tue, 19 Jan 2021 19:51:43 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:32c8:5054:ff:fe00:142]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l1x2S-0005lE-PG for linux-arm-kernel@lists.infradead.org; Tue, 19 Jan 2021 19:51:41 +0000 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=UJ+Gl/MaDzjeCMELmpBWNOHj8O0WSEwffGTVaKOBVEQ=; b=QxraNCTC4MflqIu9deqkCBkhj HxP0pJZBn4jwEjihHZ9Q93NA41LnHgrq7abJLJZhWi95gNOnksT4spRMPfqs9W75hlSRXzwL6gTNk kE6rY1JZlDuaAqt62UEt4TXz/vTtTehmFy8Q/du4STls0wCu8m17JQOTEHaa2Q3jsgAPpIzCUHvWM lPy39TN85gVPABUQXTpglDyAGps03/iaTAkPZTdNGGCQSyEvES9uYIkUZfrr+Ydtxt2doUS7alMju lJUyrM9ulnPGKrwb2w/CpF4TTRwMC4hViIRXlGrbMb84GlpDc/c0gdzJ747s2OX1fQAsIJRTDZ5Nf 0A9HTS4Cw==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:50094) by pandora.armlinux.org.uk with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1l1wzM-0007oe-QA; Tue, 19 Jan 2021 19:48:28 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1l1wzL-0005I6-8L; Tue, 19 Jan 2021 19:48:27 +0000 Date: Tue, 19 Jan 2021 19:48:27 +0000 From: Russell King - ARM Linux admin To: Dmitry Vyukov Subject: Re: Arm + KASAN + syzbot Message-ID: <20210119194827.GL1551@shell.armlinux.org.uk> References: <20210119111319.GH1551@shell.armlinux.org.uk> <20210119114341.GI1551@shell.armlinux.org.uk> <20210119123659.GJ1551@shell.armlinux.org.uk> 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-20210119_145140_833917_3D3A8524 X-CRM114-Status: GOOD ( 15.75 ) 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: Arnd Bergmann , Linus Walleij , kasan-dev , syzkaller , Krzysztof Kozlowski , Hailong Liu , 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 Tue, Jan 19, 2021 at 07:57:16PM +0100, Dmitry Vyukov wrote: > Using "-kernel arch/arm/boot/zImage -dtb > arch/arm/boot/dts/vexpress-v2p-ca15-tc1.dtb" fully works. Good. > Using just "-kernel arch/arm/boot/zImage" does not work, not output > from qemu whatsoever (expected). Yep. > But using just "-kernel arch/arm/boot/zImage.dtb" gives an interesting > effect. Kernel starts booting, I see console output up to late init > stages, but then it can't find the root device. > So appended dtb works... but only in half. Is names of block devices > something that's controlled by dtb? My knowledge about this is limited to qemu being used for KVM. Firstly, there is are no block devices except for MTD, USB, or CF based block devices in the Versatile Express hardware. So, the DTB contains no block devices. In your first case above, it is likely that QEMU modifies the passed DTB to add PCIe devices to describe a virtio block device. In this case, because QEMU has no visibility of the appended DTB, it can't modify it, so the kernel only knows about devices found on the real hardware. Hence, any of the "special" virtio devices that QEMU use likely won't be found. I'm not sure how QEMU adds those (you're probably in a better position than I to boot using your first method, grab a copy of the DTB that the booted kernel used from /sys/firmware/fdt, and use dtc to turn it back into a dts and see what the changes are. I suspect you'll find that there's a new PCIe controller been added by QEMU, behind which will be a load of virtio devices for things like network and the "vda" block device. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel