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 04BE4E77180 for ; Tue, 10 Dec 2024 10:10:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 782146B0167; Tue, 10 Dec 2024 05:10:40 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 732496B0168; Tue, 10 Dec 2024 05:10:40 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 584FF6B0169; Tue, 10 Dec 2024 05:10:40 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 31DA86B0167 for ; Tue, 10 Dec 2024 05:10:40 -0500 (EST) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id DBBA0A0620 for ; Tue, 10 Dec 2024 10:10:39 +0000 (UTC) X-FDA: 82878628644.17.89A9AB9 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf27.hostedemail.com (Postfix) with ESMTP id 822FB4001E for ; Tue, 10 Dec 2024 10:10:12 +0000 (UTC) Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="UomKj/Oh"; spf=pass (imf27.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1733825423; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=WHKaqHT8TmPKp+vfFyKZV4r9sjaGCxpUSBkDEyH4Mpw=; b=eDi39evoePHj6lOHN724M+OQVZoq7QxYV5jYENoieXc2zkIFOPH73wbpsYdt1p7NbIEeT2 2gN7SHMZlqAy78AeSo8hYr9iJQhvBPT0t5p/P/EVmrNcsxUxk4KqojzyzFOKrx2LwVwQJi wMsUviLVO32k1n5M6wh42NXj3K48fmQ= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1733825423; a=rsa-sha256; cv=none; b=G4xKy5+elE3eT5/cl8Pkh3S2N5te6DyUzyCnuVt3ic3Uy3lWJLS10NnXLgposfZyAmGO8k SR2Kvjp1fUKKcJ0dA9w0onZw8InDGlc/lv9KqvMtopq82aKmxA6UsGxtMWfZXZ6KIOoQsj F7AgSWoi569t29sAwh1hCtCvTmpQMH8= ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="UomKj/Oh"; spf=pass (imf27.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1733825436; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=WHKaqHT8TmPKp+vfFyKZV4r9sjaGCxpUSBkDEyH4Mpw=; b=UomKj/Oh2j7xLqZFEUIC20ADp38z7b0nIv+JJuIkM2nH/o2500COwXfMY0SiZjPARcVDJ2 vwZtaLsMhUuOQUbgp5+8PhGAkrloM3fXOiPgS3GKtlRMn5oOPWrhxPI3DMCIov8APt8PIN 1S3gPMwGIpzs5fDZoCUpDUJYfAeDgso= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-668-bymxNI-1NiOBKdQ5Vp2cvA-1; Tue, 10 Dec 2024 05:10:35 -0500 X-MC-Unique: bymxNI-1NiOBKdQ5Vp2cvA-1 X-Mimecast-MFC-AGG-ID: bymxNI-1NiOBKdQ5Vp2cvA Received: by mail-wr1-f70.google.com with SMTP id ffacd0b85a97d-385df115300so2981282f8f.2 for ; Tue, 10 Dec 2024 02:10:35 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1733825434; x=1734430234; h=content-transfer-encoding:in-reply-to:organization:autocrypt :content-language:from:references:cc:to:subject:user-agent :mime-version:date:message-id:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to; bh=WHKaqHT8TmPKp+vfFyKZV4r9sjaGCxpUSBkDEyH4Mpw=; b=bQsM1Fsgb+682hT6t9b7pfWQNxjeKr2jcBkJeunBoZEeDhq5ee2MKxF8iZYZfGOQ3r 79nCbTEqbQHqsHHtSbpGf+0hBdKVRGru3Vo9ud1bL4AiTHBf6/2XsqSTGOTwKcJLSE9+ eAoiG/PMwTvEimRVS1HsrQbFLdGT5unJ8t/fJbjNCRex9sCFlKn5P7/wYHrMwBBZKL90 ZlwDgZsVkOLlb6XVMwwJXOUY1JQbRcxuWQ7PqTGGRxV5GI14hXCNRpsUyfEEqe14VkKR 3wjSq3yJleCG+S90Idhh5wvYLuFrnohEOA0rP6Ske6bgXzYsxx8EwXLGnubGutNmgMHW QC2Q== X-Gm-Message-State: AOJu0Yyj5VD2rc1BNsfhaGBVISI0SOXXjmZWhux7GxpcNAlpVK9KOKMN 5OmCJ4iqxwqY7vPrqtLkanZJZe+UID8I9HqQFcEl/uxN5wIPYmeQRAPc7Es2w25YZavRvhJkek6 cjQlYXPKCGMMjxJZLFcKFkDZ5akhzxgaaVvN63vwXBe7sO+4R X-Gm-Gg: ASbGnctPPY3BoiwuJaAtmzvzeJjE0TUVh+ltRrgtbhBGbgaOnX7Ia0D2Slw4XpFnW/F tb8telNYPdXf1KBc9hj/XBaljkdp/oKLM4n+6IDDIxsJ+FmqKIJlmPgigQXJBKJiL6Mg4fQ9Ivy eE1UFbANsJLEUoTt4h9tqkXi1/hSwajH+h3UI0ITRMGSiHd59OXXsDtn7Oc6GWpWAR0yHm0x+ih isbU8kG7JRdytB2oZgURREWHfyozv3nMQAj8hxXa1Tw3bL9b0vU5PF2Zd2qkxTz7/Lq7VO87Jlg nQJBYKV1FJStvUxBKTDdlqgXrf4zZnaq1eOaZ78UcNn0Ludi5McjpMZqSsaDivbQiJZisRSVLDX UZ762fw== X-Received: by 2002:a5d:5f8e:0:b0:386:3803:bbd8 with SMTP id ffacd0b85a97d-3863803bdc1mr8557222f8f.59.1733825434214; Tue, 10 Dec 2024 02:10:34 -0800 (PST) X-Google-Smtp-Source: AGHT+IH+VnuFpTTDtc9IBkNAkw6YO/9HOkWYUVF564g0JrmQz1f6HgbOaLN8ZjLolBzYrdtJsxAHDQ== X-Received: by 2002:a5d:5f8e:0:b0:386:3803:bbd8 with SMTP id ffacd0b85a97d-3863803bdc1mr8557197f8f.59.1733825433837; Tue, 10 Dec 2024 02:10:33 -0800 (PST) Received: from ?IPV6:2003:cb:c723:b800:9a60:4b46:49f9:87f3? (p200300cbc723b8009a604b4649f987f3.dip0.t-ipconnect.de. [2003:cb:c723:b800:9a60:4b46:49f9:87f3]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-434da0d26b0sm190812545e9.9.2024.12.10.02.10.31 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 10 Dec 2024 02:10:32 -0800 (PST) Message-ID: <69d2c332-04f1-43df-950f-931f20ad725e@redhat.com> Date: Tue, 10 Dec 2024 11:10:31 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1] mm/page_alloc: don't call pfn_to_page() on possibly non-existent PFN in split_large_buddy() To: Vlastimil Babka , linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, Andrew Morton , Johannes Weiner , Zi Yan , Yu Zhao , stable@vger.kernel.org References: <20241210093437.174413-1-david@redhat.com> From: David Hildenbrand Autocrypt: addr=david@redhat.com; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW AgMBAh4BAheAAhkBFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl8Ox4kFCRKpKXgACgkQTd4Q 9wD/g1oHcA//a6Tj7SBNjFNM1iNhWUo1lxAja0lpSodSnB2g4FCZ4R61SBR4l/psBL73xktp rDHrx4aSpwkRP6Epu6mLvhlfjmkRG4OynJ5HG1gfv7RJJfnUdUM1z5kdS8JBrOhMJS2c/gPf wv1TGRq2XdMPnfY2o0CxRqpcLkx4vBODvJGl2mQyJF/gPepdDfcT8/PY9BJ7FL6Hrq1gnAo4 3Iv9qV0JiT2wmZciNyYQhmA1V6dyTRiQ4YAc31zOo2IM+xisPzeSHgw3ONY/XhYvfZ9r7W1l pNQdc2G+o4Di9NPFHQQhDw3YTRR1opJaTlRDzxYxzU6ZnUUBghxt9cwUWTpfCktkMZiPSDGd KgQBjnweV2jw9UOTxjb4LXqDjmSNkjDdQUOU69jGMUXgihvo4zhYcMX8F5gWdRtMR7DzW/YE BgVcyxNkMIXoY1aYj6npHYiNQesQlqjU6azjbH70/SXKM5tNRplgW8TNprMDuntdvV9wNkFs 9TyM02V5aWxFfI42+aivc4KEw69SE9KXwC7FSf5wXzuTot97N9Phj/Z3+jx443jo2NR34XgF 89cct7wJMjOF7bBefo0fPPZQuIma0Zym71cP61OP/i11ahNye6HGKfxGCOcs5wW9kRQEk8P9 M/k2wt3mt/fCQnuP/mWutNPt95w9wSsUyATLmtNrwccz63XOwU0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAHCwXwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCXw7HsgUJEqkpoQAKCRBN3hD3AP+DWrrpD/4qS3dyVRxDcDHIlmguXjC1Q5tZTwNB boaBTPHSy/Nksu0eY7x6HfQJ3xajVH32Ms6t1trDQmPx2iP5+7iDsb7OKAb5eOS8h+BEBDeq 3ecsQDv0fFJOA9ag5O3LLNk+3x3q7e0uo06XMaY7UHS341ozXUUI7wC7iKfoUTv03iO9El5f XpNMx/YrIMduZ2+nd9Di7o5+KIwlb2mAB9sTNHdMrXesX8eBL6T9b+MZJk+mZuPxKNVfEQMQ a5SxUEADIPQTPNvBewdeI80yeOCrN+Zzwy/Mrx9EPeu59Y5vSJOx/z6OUImD/GhX7Xvkt3kq Er5KTrJz3++B6SH9pum9PuoE/k+nntJkNMmQpR4MCBaV/J9gIOPGodDKnjdng+mXliF3Ptu6 3oxc2RCyGzTlxyMwuc2U5Q7KtUNTdDe8T0uE+9b8BLMVQDDfJjqY0VVqSUwImzTDLX9S4g/8 kC4HRcclk8hpyhY2jKGluZO0awwTIMgVEzmTyBphDg/Gx7dZU1Xf8HFuE+UZ5UDHDTnwgv7E th6RC9+WrhDNspZ9fJjKWRbveQgUFCpe1sa77LAw+XFrKmBHXp9ZVIe90RMe2tRL06BGiRZr jPrnvUsUUsjRoRNJjKKA/REq+sAnhkNPPZ/NNMjaZ5b8Tovi8C0tmxiCHaQYqj7G2rgnT0kt WNyWQQ== Organization: Red Hat In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: lsd0JOFNO9zeIgEETMnLobIvMQD5XbPjJEmshlijhPw_1733825434 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 822FB4001E X-Stat-Signature: ai614x7yay8m8gtsczcqm9fusbipcrsg X-Rspam-User: X-HE-Tag: 1733825412-949116 X-HE-Meta: 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 qYh+rYyy 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000071, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 10.12.24 10:48, Vlastimil Babka wrote: > On 12/10/24 10:34, David Hildenbrand wrote: >> In split_large_buddy(), we might call pfn_to_page() on a PFN that might >> not exist. In corner cases, such as when freeing the highest pageblock in >> the last memory section, this could result with CONFIG_SPARSEMEM && >> !CONFIG_SPARSEMEM_EXTREME in __pfn_to_section() returning NULL and >> and __section_mem_map_addr() dereferencing that NULL pointer. >> >> Let's fix it, and avoid doing a pfn_to_page() call for the first >> iteration, where we already have the page. >> >> So far this was found by code inspection, but let's just CC stable as >> the fix is easy. >> >> Fixes: fd919a85cd55 ("mm: page_isolation: prepare for hygienic freelists") >> Reported-by: Vlastimil Babka >> Closes: https://lkml.kernel.org/r/e1a898ba-a717-4d20-9144-29df1a6c8813@suse.cz >> Cc: Andrew Morton >> Cc: Johannes Weiner >> Cc: Zi Yan >> Cc: Yu Zhao >> Cc: >> Signed-off-by: David Hildenbrand > > Reviewed-by: Vlastimil Babka BTW, staring at nr_isolate_pageblock accounting, I just stumbled over prep_move_freepages_block(), and I am not sure about the zone_spans_pfn() checks in there. With overlapping zones, these are not reliably, which makes me believe that maybe these checks are not required at all. Or that there is a bug. Or that there is some implication that these checks are only required on systems without overlapping zones :) -- Cheers, David / dhildenb