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=-3.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 E2BB0C43603 for ; Wed, 4 Dec 2019 14:54:58 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A3307206DF for ; Wed, 4 Dec 2019 14:54:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lca.pw header.i=@lca.pw header.b="KSg12ndI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A3307206DF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lca.pw Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 29D326B0B1D; Wed, 4 Dec 2019 09:54:58 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 24D636B0B1E; Wed, 4 Dec 2019 09:54:58 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 13CBF6B0B1F; Wed, 4 Dec 2019 09:54:58 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0105.hostedemail.com [216.40.44.105]) by kanga.kvack.org (Postfix) with ESMTP id EE57C6B0B1D for ; Wed, 4 Dec 2019 09:54:57 -0500 (EST) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id 8FAC149960D for ; Wed, 4 Dec 2019 14:54:57 +0000 (UTC) X-FDA: 76227756234.16.store55_2b3b80fdd840b X-HE-Tag: store55_2b3b80fdd840b X-Filterd-Recvd-Size: 6672 Received: from mail-qv1-f68.google.com (mail-qv1-f68.google.com [209.85.219.68]) by imf13.hostedemail.com (Postfix) with ESMTP for ; Wed, 4 Dec 2019 14:54:56 +0000 (UTC) Received: by mail-qv1-f68.google.com with SMTP id i3so3140707qvv.7 for ; Wed, 04 Dec 2019 06:54:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lca.pw; s=google; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=VhtN6w8f3pAFcQOPcFVj26+n4AG9pW+AqI+0CrhF1WY=; b=KSg12ndIh9E3OIht1yFvbbmEtc8FFzzewpaSfmPIqXwlXeWvOymL97PMX/XzdfRlbr ssdo3mdWSCre7Rqcf8zB/S3lc82MUW0i10UrOzZfpSihfkcr7DVTzTjLhllcQ5HN3FnS dx+zGEpPHgYZJnR+ZbJfru1Id/k9igxNsd1qA0yR+IRtskJsNtJvXJJqcT22f+dhHTWr u4wDmt+y3OzqPWEWKthpgKnqNqm9wyekNxyc/zNRKT+l3fYxPdx2qa2gq2MbBHQPvU75 LSmG0P16brd+GiDYbaaytEyTd/UMlJ+ro7/Qc0V5eATPEi7JH1FqZZ7Qp/b2oN6hpmL9 8xoQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=VhtN6w8f3pAFcQOPcFVj26+n4AG9pW+AqI+0CrhF1WY=; b=m997UbA4U9SmWQM6eygnWe3NCrax/WLsFz/bgf+gOPCe1+5ePDyP3RIwJ2CZTi3Paz hHFeCDTmtMg8ZArrJQ80m9Z+9k/q9NWWFQtI4uVtDdXtdfqVAI7dMHyvEn67us6k1Lc+ zshWA+oEbDatGr9ZPu+xLu5ZpeKqFlh4bSh5JNPhTOYoIzqjUAPDWcyX+2G0ClVLxWhc hpMWC3sSLJ4AA+f9pr5oFbyiGjo5+2Nf4zos4dpT4RcIsxhJZPsOpB4+xUk0mZlwEW98 MMVIEbfQlHBHVo/NbpZ2YWfhzCWoIEU9OC+mcONq3eQj5YCU7lDR2MiMUJb1+y81RmSI 4qyg== X-Gm-Message-State: APjAAAVBSXkH1yxXGdCPYaTy8BPbolHFGFI/j36O/eOXpQfpQ95F1oOA uT+bSI45f8Y0ZJ8/aUbubWm1nw== X-Google-Smtp-Source: APXvYqzbyvSvXC4KIUt2KO2kzgGROo0QY8Fmwq3x8ulH4VJBTtydvOViz6rnhzz4/LfQ4aet+tQNiw== X-Received: by 2002:a0c:f68f:: with SMTP id p15mr2886839qvn.79.1575471296051; Wed, 04 Dec 2019 06:54:56 -0800 (PST) Received: from [192.168.1.153] (pool-71-184-117-43.bstnma.fios.verizon.net. [71.184.117.43]) by smtp.gmail.com with ESMTPSA id y184sm3732454qkd.128.2019.12.04.06.54.54 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 04 Dec 2019 06:54:55 -0800 (PST) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 13.0 \(3601.0.10\)) Subject: Re: [PATCH v15 00/23] Generic page walk and ptdump From: Qian Cai In-Reply-To: <911fac4a-2204-f994-a101-16a60fba12e8@redhat.com> Date: Wed, 4 Dec 2019 09:54:53 -0500 Cc: Steven Price , Andrew Morton , Linux-MM , Mark Rutland , the arch/x86 maintainers , Arnd Bergmann , Ard Biesheuvel , Peter Zijlstra , Catalin Marinas , Dave Hansen , linux-kernel@vger.kernel.org, =?utf-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Ingo Molnar , Borislav Petkov , Andy Lutomirski , "H. Peter Anvin" , James Morse , Thomas Gleixner , Will Deacon , linux-arm-kernel@lists.infradead.org, "Liang, Kan" Content-Transfer-Encoding: quoted-printable Message-Id: <0FA196FD-3FCD-431A-AA3E-21BF00EA07DC@lca.pw> References: <20191101140942.51554-1-steven.price@arm.com> <1572896147.5937.116.camel@lca.pw> <7B040741-EC8A-4CC0-964B-4046AE2E617A@lca.pw> <16da6118-ac4d-a165-6202-0731a776ac72@arm.com> <911fac4a-2204-f994-a101-16a60fba12e8@redhat.com> To: David Hildenbrand X-Mailer: Apple Mail (2.3601.0.10) 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: > On Dec 3, 2019, at 6:02 AM, David Hildenbrand = wrote: >=20 > On 06.11.19 16:05, Steven Price wrote: >> On 06/11/2019 13:31, Qian Cai wrote: >>>=20 >>>=20 >>>> On Nov 4, 2019, at 2:35 PM, Qian Cai wrote: >>>>=20 >>>> On Fri, 2019-11-01 at 14:09 +0000, Steven Price wrote: >> [...] >>>>> Changes since v14: >>>>> = https://lore.kernel.org/lkml/20191028135910.33253-1-steven.price@arm.com/ >>>>> * Switch walk_page_range() into two functions, the existing >>>>> walk_page_range() now still requires VMAs (and treats areas = without a >>>>> VMA as a 'hole'). The new walk_page_range_novma() ignores VMAs = and >>>>> will report the actual page table layout. This fixes the = previous >>>>> breakage of /proc//pagemap >>>>> * New patch at the end of the series which reduces the 'level' = numbers >>>>> by 1 to simplify the code slightly >>>>> * Added tags >>>>=20 >>>> Does this new version also take care of this boot crash seen with = v14? Suppose >>>> it is now breaking CONFIG_EFI_PGT_DUMP=3Dy? The full config is, >>>>=20 >>>> https://raw.githubusercontent.com/cailca/linux-mm/master/x86.config >>>>=20 >>>=20 >>> V15 is indeed DOA here. >>=20 >> Thanks for finding this, it looks like EFI causes issues here. The = below fixes >> this for me (booting in QEMU). >>=20 >> Andrew: do you want me to send out the entire series again for this = fix, or >> can you squash this into mm-pagewalk-allow-walking-without-vma.patch? >>=20 >> Thanks, >>=20 >> Steve >>=20 >> ---8<--- >> diff --git a/mm/pagewalk.c b/mm/pagewalk.c >> index c7529dc4f82b..70dcaa23598f 100644 >> --- a/mm/pagewalk.c >> +++ b/mm/pagewalk.c >> @@ -90,7 +90,7 @@ static int walk_pmd_range(pud_t *pud, unsigned long = addr, unsigned long end, >> split_huge_pmd(walk->vma, pmd, addr); >> if (pmd_trans_unstable(pmd)) >> goto again; >> - } else if (pmd_leaf(*pmd)) { >> + } else if (pmd_leaf(*pmd) || !pmd_present(*pmd)) { >> continue; >> } >>=20 >> @@ -141,7 +141,7 @@ static int walk_pud_range(p4d_t *p4d, unsigned = long addr, unsigned long end, >> split_huge_pud(walk->vma, pud, addr); >> if (pud_none(*pud)) >> goto again; >> - } else if (pud_leaf(*pud)) { >> + } else if (pud_leaf(*pud) || !pud_present(*pud)) { >> continue; >> } >>=20 >>=20 >=20 > Even with this fix, booting for me under QEMU fails. See >=20 > = https://lore.kernel.org/linux-mm/b7ce62f2-9a48-6e48-6685-003431e521aa@redh= at.com/ >=20 Yes, for some reasons, this starts to crash on almost all arches here, = so it might be worth for Andrew to revert those in the meantime while allowing Steven to = rework.