From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail02.groups.io (mail02.groups.io [66.175.222.108]) by spool.mail.gandi.net (Postfix) with ESMTPS id 45CD6AC12D0 for ; Thu, 19 Oct 2023 13:04:52 +0000 (UTC) DKIM-Signature: a=rsa-sha256; bh=Q4/4vEwuVpWNpoOH7KTJOLKpubVxArwbn6H5AYOMJN4=; c=relaxed/simple; d=groups.io; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From:In-Reply-To:Precedence:List-Subscribe:List-Help:Sender:List-Id:Mailing-List:Delivered-To:Reply-To:List-Unsubscribe-Post:List-Unsubscribe:Content-Language:Content-Type:Content-Transfer-Encoding; s=20140610; t=1697720690; v=1; b=QRBQIUawNeDuW3xRa/tIjpLwmqWyp0dahY9SKnuhyjAtZnJvR71YDyk+yrSI8S/49yplGDnQ XeqTUy/5l9rOtIYDgA16NF34ne08gWwEzy/dLsyAuKUbUd4fnAnai37430AWOIw1JQnHHdOL7WA W45auuToEhstBFAxa3stxEdg= X-Received: by 127.0.0.2 with SMTP id VEzqYY7687511x1FlAFnMnR6; Thu, 19 Oct 2023 06:04:50 -0700 X-Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by mx.groups.io with SMTP id smtpd.web10.27239.1697720690081636447 for ; Thu, 19 Oct 2023 06:04:50 -0700 X-Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-206-p5MrKtR7O3-YVQrolrg2Jw-1; Thu, 19 Oct 2023 09:04:33 -0400 X-MC-Unique: p5MrKtR7O3-YVQrolrg2Jw-1 X-Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 424CA10201FD; Thu, 19 Oct 2023 13:04:33 +0000 (UTC) X-Received: from [10.39.193.11] (unknown [10.39.193.11]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3A1542166B26; Thu, 19 Oct 2023 13:04:32 +0000 (UTC) Message-ID: <08ebf53a-472d-d738-dab9-150150ce5be8@redhat.com> Date: Thu, 19 Oct 2023 15:04:30 +0200 MIME-Version: 1.0 Subject: Re: [edk2-devel] [PATCH] OvmfPkg/VirtioFsDxe: tolerate opening an abs. pathname rel. to a reg. file To: devel@edk2.groups.io, kraxel@redhat.com Cc: Ard Biesheuvel , Jiewen Yao , Jordan Justen References: <20231018172434.91280-1-lersek@redhat.com> <3wcxiedm4dlq5sr4qhswrmdkfvtgapygev2vkwagrqla6oskqc@wzwffqbeaqej> From: "Laszlo Ersek" In-Reply-To: <3wcxiedm4dlq5sr4qhswrmdkfvtgapygev2vkwagrqla6oskqc@wzwffqbeaqej> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.6 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Precedence: Bulk List-Subscribe: List-Help: Sender: devel@edk2.groups.io List-Id: Mailing-List: list devel@edk2.groups.io; contact devel+owner@edk2.groups.io Reply-To: devel@edk2.groups.io,lersek@redhat.com List-Unsubscribe-Post: List-Unsubscribe=One-Click List-Unsubscribe: X-Gm-Message-State: MOwthFHOMYG1zHRfX8ODKVnBx7686176AA= Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-GND-Status: LEGIT Authentication-Results: spool.mail.gandi.net; dkim=pass header.d=groups.io header.s=20140610 header.b=QRBQIUaw; dmarc=fail reason="SPF not aligned (relaxed), DKIM not aligned (relaxed)" header.from=redhat.com (policy=none); spf=pass (spool.mail.gandi.net: domain of bounce@groups.io designates 66.175.222.108 as permitted sender) smtp.mailfrom=bounce@groups.io On 10/19/23 08:28, Gerd Hoffmann wrote: > On Wed, Oct 18, 2023 at 07:24:34PM +0200, Laszlo Ersek wrote: >> Referring to a file relative to a regular file makes no sense (or at lea= st >> it cannot be implemented consistently with how a file is referred to >> relative to a directory). VirtioFsSimpleFileOpen() has enforced this >> strictly since the beginning, and a few months ago I reported USWG Manti= s >> ticket #2367 [1] too, for clearing up the related confusion in the UEFI >> spec. >> >> Unfortunately, the shim boot loader contains such a bug [2] [3]. I don't >> believe the shim bug is ever going to be fixed. We can however relax the >> check in VirtioFsSimpleFileOpen() a bit: if the pathname that's being >> opened relative to a regular file is absolute, then the base file is goi= ng >> to be ignored anyway, so we can let the caller's bug slide. This happens >> to make shim work. >> >> Why this matters: UEFI-bootable Linux installer ISOs tend to come with >> shim and grub in the embedded (ElTorito) FAT image (ESP). Sometimes you >> want to build upstream shim/grub binaries, but boot the same ISO >> otherwise. The fastest way for overriding the ESP for this purpose is to >> copy its original contents to a virtio filesystem, then overwrite the sh= im >> and grub binaries from the host side. Note that this is different from >> direct-booting a kernel (via fw_cfg); the point is to check whether the >> just-built shim and grub are able to boot the rest of the ISO. >> >> [1] https://mantis.uefi.org/mantis/view.php?id=3D2367 >> [2] https://bugzilla.redhat.com/show_bug.cgi?id=3D1966973 >> [3] https://github.com/rhboot/shim/issues/382 >> >> Cc: Ard Biesheuvel >> Cc: Gerd Hoffmann >> Cc: Jiewen Yao >> Cc: Jordan Justen >> Signed-off-by: Laszlo Ersek >=20 > Reviewed-by: Gerd Hoffmann > Tested-by: Gerd Hoffmann Merged via ; commit 8abbf6d87e68. Thanks! Laszlo -=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#109804): https://edk2.groups.io/g/devel/message/109804 Mute This Topic: https://groups.io/mt/102044004/7686176 Group Owner: devel+owner@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/leave/12367111/7686176/19134562= 12/xyzzy [rebecca@openfw.io] -=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-