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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32B79C433F5 for ; Tue, 21 Dec 2021 14:24:51 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id AC9876B0078; Tue, 21 Dec 2021 09:24:50 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A79536B007B; Tue, 21 Dec 2021 09:24:50 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9410E6B007D; Tue, 21 Dec 2021 09:24:50 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0218.hostedemail.com [216.40.44.218]) by kanga.kvack.org (Postfix) with ESMTP id 84A446B0078 for ; Tue, 21 Dec 2021 09:24:50 -0500 (EST) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 36BB288CD2 for ; Tue, 21 Dec 2021 14:24:50 +0000 (UTC) X-FDA: 78942022740.15.15A28D8 Received: from mail-pl1-f170.google.com (mail-pl1-f170.google.com [209.85.214.170]) by imf30.hostedemail.com (Postfix) with ESMTP id BA69C80032 for ; Tue, 21 Dec 2021 14:24:49 +0000 (UTC) Received: by mail-pl1-f170.google.com with SMTP id j13so1420836plx.4 for ; Tue, 21 Dec 2021 06:24:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:to:cc:references :from:in-reply-to:content-transfer-encoding; bh=cLkvxmmpuEZaFih+WohbYipB6VYzB16BcCBqKzVBa28=; b=aZvD0T10xjL70xBG6nrHdpJo633d5UrYE93iwitnJgfH285fdrat7fpPUvDu2YBopW KTa0EiGmjXRDIUw/XJaUMVfeoGMWM6lvSwBvloI8qQCuWUN0tFMj3jBNrfXGZOleOTaV Ix8rhQpQ9cdIG2IATWzZqXcfgoiKNGbu1ZlsERE9EG2wIggYO4QarAkUY/ZZnHCdbrqZ ZssszCy09ti8XmPOirqmFnCpVaOriUjHyiyO9qOmbtrPw9vxI4tuRvatUCyZgJsWctCB FxaXys/3lrKkMr9FOwOMQzUAYpxEZJ6llKV1XQvplIvjm7poguSrCWemop3uOmZCZx5A 7RFw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :to:cc:references:from:in-reply-to:content-transfer-encoding; bh=cLkvxmmpuEZaFih+WohbYipB6VYzB16BcCBqKzVBa28=; b=3T+73rS9dlIssU00flHfI836eSc02Ce/uBgV+/01++7WrMzQOqG81G0CAusEl7TWDL oAJNOClugkc+LsEvRoqC++7Edve7ppUiidscxRZxY7HBqcBVjS4R8+1oLrKGW1d0XPdF HhFqgflU+PzgJjPiwadYlGDJhkR3dyF9z3BcFNGsZ0cMbkJx8QGep3OyuHiwNxuvoJ++ 7MsFvokXummQt9Vhfo1/ePDcZ+s7fzFIzkfmNrwwkXhr18UFOpzTMK8HST6HpSwtoOA3 kyx+sdy1fIH0Ugy48UFmVrjxnT/1flInM4mzVdPmYKlJZ9PNpuaWgNomQpzFSVqF/oxQ PWDQ== X-Gm-Message-State: AOAM532sCwJn0a6SJ4gDO8a4WH1baSUfToODHz6QdCUcB2EC6jTP5MWK XzBKHx+CdAHFiq05eNFXN7s= X-Google-Smtp-Source: ABdhPJy9DyVWNvICSIfWIV3uumeU3kNyTWiKRonBxMMPuHU5/XLyKhHbOYqY5RrZ5B82/EDuhes4Ow== X-Received: by 2002:a17:902:ba84:b0:142:5514:8dd6 with SMTP id k4-20020a170902ba8400b0014255148dd6mr3564486pls.19.1640096688641; Tue, 21 Dec 2021 06:24:48 -0800 (PST) Received: from [30.240.97.243] ([205.204.117.107]) by smtp.gmail.com with ESMTPSA id f14sm3005238pfv.215.2021.12.21.06.24.46 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 21 Dec 2021 06:24:48 -0800 (PST) Message-ID: <5adf42d2-649d-adcc-4598-26263ca27a31@gmail.com> Date: Tue, 21 Dec 2021 22:24:44 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.4.0 Subject: Re: [PATCH v2] virtio_mem: fix panic on mb_states indexing overflow To: David Hildenbrand , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, vbabka@suse.cz, ziy@nvidia.com References: <32103255-7eba-08c1-8ab8-0730486332c1@redhat.com> <14ac1cb4-1cf0-03a3-d412-c35fa9eeea59@redhat.com> From: Eric Ren In-Reply-To: <14ac1cb4-1cf0-03a3-d412-c35fa9eeea59@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed X-Rspamd-Queue-Id: BA69C80032 X-Stat-Signature: pycaw8xdfuozyndkhjrufrj71b8aen1n Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=aZvD0T10; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf30.hostedemail.com: domain of renzhengeek@gmail.com designates 209.85.214.170 as permitted sender) smtp.mailfrom=renzhengeek@gmail.com X-Rspamd-Server: rspam02 X-HE-Tag: 1640096689-87439 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi David, =E5=9C=A8 12/21/21 9:53 PM, David Hildenbrand =E5=86=99=E9=81=93: > Hi Eric, > >> _vm->sbm.first_mb_id =3D=3D 0 > ^ that's precisely what I meant. Ah, finally got it! > > How could it *ever* be safe on x86-64 to let a virtio-mem device start > on physical address 0, eventually overlapping essentially all DMA, the > BIOS and the PCI hole. You're right! That clears my doubt why this "issue" can live so long=20 there... util I see it. Yes, my setup is a very hacking enviroment. The device region start addr=20 is wrongly assigned to 0! So, let's just drop this patch. Eric > > Thus my question: Is this a "fix" for x86-64 or is this a "prepare for" > for !x86-64 (e.g., arm64). > > If it's a fix, we want proper "Fixes:" and "Cc: stable" tags. But I > assume this is much rather a preparation for another architecture than > x86-64. > > Thanks! >