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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 835BFCA0FE2 for ; Thu, 21 Aug 2025 20:32:47 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CEED98E004D; Thu, 21 Aug 2025 16:32:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CC69B8E0048; Thu, 21 Aug 2025 16:32:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BDC738E004D; Thu, 21 Aug 2025 16:32:46 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id A88298E0048 for ; Thu, 21 Aug 2025 16:32:46 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 5A47E138C2C for ; Thu, 21 Aug 2025 20:32:46 +0000 (UTC) X-FDA: 83801913132.13.3EA56FE Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf19.hostedemail.com (Postfix) with ESMTP id 99E931A0003 for ; Thu, 21 Aug 2025 20:32:44 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=none; spf=pass (imf19.hostedemail.com: domain of "SRS0=upZg=3B=redhat.com=david@kernel.org" designates 172.105.4.254 as permitted sender) smtp.mailfrom="SRS0=upZg=3B=redhat.com=david@kernel.org"; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=redhat.com (policy=quarantine) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1755808364; 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; bh=6cYPmh3HQgcyfvWz/UYplifrNr+DYa+NwnJTcdL0h7M=; b=LhbJk41gfRPdHKAOBt28Y2ZzXToSYjWz39HLbaVObmXFNVx8O989VOcfFOmTTcpApKjm75 /r/ZF0jCBJy1dfucsYft3soYIDg95QQ7XStt4EkZDl/LwM1JNvEKiUkJNzwWMVXImfLwJv cF0fTcmaE+J58Y4QcOiO7v1tFEVg+XU= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=none; spf=pass (imf19.hostedemail.com: domain of "SRS0=upZg=3B=redhat.com=david@kernel.org" designates 172.105.4.254 as permitted sender) smtp.mailfrom="SRS0=upZg=3B=redhat.com=david@kernel.org"; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=redhat.com (policy=quarantine) ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1755808364; a=rsa-sha256; cv=none; b=gLYNCOsKfct5iI6Ewnzly3oObRjfDEizdeA7A7EkHxiTl6IJR73iodfZiz8vbpCWjHxTx/ rFBuY+LBfpj2Gwj/zTLpxw33M8NbDD6c/YmqCkm6ErBXkaIl6KjIZbaLz/zAgDDfYqcTZi zLKfFZPDzWR801JVo2KTFu+tLmXRLUU= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 92481601F8; Thu, 21 Aug 2025 20:32:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9632BC4CEEB; Thu, 21 Aug 2025 20:32:31 +0000 (UTC) Message-ID: <1a13a5cb-4312-4c01-827b-fa8a029df0f1@redhat.com> Date: Thu, 21 Aug 2025 22:32:29 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH RFC 33/35] kfence: drop nth_page() usage To: linux-kernel@vger.kernel.org Cc: Alexander Potapenko , Marco Elver , Dmitry Vyukov , Andrew Morton , Brendan Jackman , Christoph Lameter , Dennis Zhou , dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, iommu@lists.linux.dev, io-uring@vger.kernel.org, Jason Gunthorpe , Jens Axboe , Johannes Weiner , John Hubbard , kasan-dev@googlegroups.com, kvm@vger.kernel.org, "Liam R. Howlett" , Linus Torvalds , linux-arm-kernel@axis.com, linux-arm-kernel@lists.infradead.org, linux-crypto@vger.kernel.org, linux-ide@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mips@vger.kernel.org, linux-mmc@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, Lorenzo Stoakes , Marek Szyprowski , Michal Hocko , Mike Rapoport , Muchun Song , netdev@vger.kernel.org, Oscar Salvador , Peter Xu , Robin Murphy , Suren Baghdasaryan , Tejun Heo , virtualization@lists.linux.dev, Vlastimil Babka , wireguard@lists.zx2c4.com, x86@kernel.org, Zi Yan References: <20250821200701.1329277-1-david@redhat.com> <20250821200701.1329277-34-david@redhat.com> From: David Hildenbrand Content-Language: en-US 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 ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZoEEwEIAEQCGwMCF4ACGQEFCwkIBwICIgIG FQoJCAsCBBYCAwECHgcWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaJzangUJJlgIpAAKCRBN 3hD3AP+DWhAxD/9wcL0A+2rtaAmutaKTfxhTP0b4AAp1r/eLxjrbfbCCmh4pqzBhmSX/4z11 opn2KqcOsueRF1t2ENLOWzQu3Roiny2HOU7DajqB4dm1BVMaXQya5ae2ghzlJN9SIoopTWlR 0Af3hPj5E2PYvQhlcqeoehKlBo9rROJv/rjmr2x0yOM8qeTroH/ZzNlCtJ56AsE6Tvl+r7cW 3x7/Jq5WvWeudKrhFh7/yQ7eRvHCjd9bBrZTlgAfiHmX9AnCCPRPpNGNedV9Yty2Jnxhfmbv Pw37LA/jef8zlCDyUh2KCU1xVEOWqg15o1RtTyGV1nXV2O/mfuQJud5vIgzBvHhypc3p6VZJ lEf8YmT+Ol5P7SfCs5/uGdWUYQEMqOlg6w9R4Pe8d+mk8KGvfE9/zTwGg0nRgKqlQXrWRERv cuEwQbridlPAoQHrFWtwpgYMXx2TaZ3sihcIPo9uU5eBs0rf4mOERY75SK+Ekayv2ucTfjxr Kf014py2aoRJHuvy85ee/zIyLmve5hngZTTe3Wg3TInT9UTFzTPhItam6dZ1xqdTGHZYGU0O otRHcwLGt470grdiob6PfVTXoHlBvkWRadMhSuG4RORCDpq89vu5QralFNIf3EysNohoFy2A LYg2/D53xbU/aa4DDzBb5b1Rkg/udO1gZocVQWrDh6I2K3+cCs7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <20250821200701.1329277-34-david@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 99E931A0003 X-Stat-Signature: fzkq77wnf317g77gj9tywr9eo6yytp4p X-Rspamd-Server: rspam04 X-Rspam-User: X-Rspamd-Pre-Result: action=add header; module=dmarc; Action set by DMARC X-Rspam: Yes X-HE-Tag: 1755808364-858794 X-HE-Meta: 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 5h6YIhkw b7VoqZP/rVRe2cbk2/3jSqI4jCB/XVvB+NZXKSLwzLtVokgOjju9AbTYPPalttdxDygUR2dx//RgXMrr668WR5yHmKM2aqtI3OuRsoyvOb/A8c8tKOuY6++JTYmehY9pPZ7nGSKS4OIQS5pd7ddTNL/m5+mlq02sbQop9VAittZv07r1nuj5WkVsgjG4dt0zl+nse6EDm824PI0jw3Qd5H04sAkIO6P6vrq3wlVzryEVKCO2pV0WgkFcSU+lKlSQ4Xw5Uewyli4P/WkhDYUzSnpvakhkKjAVwTJvbYdBO1ia9RLcpNO/UDlwz4pI4D7+UuivFARRJ/Y3GU4pWHGGTR1y9oT5aWhJ9H8eCLg4OXMUERllXfyaUftYJwii4JCIpXmcaOJ/HpPv8iPm5srdnFHJYG184kzH3zMnqusAXuMuPam5IXBw5Zli456uysi4sMYqE 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: List-Subscribe: List-Unsubscribe: On 21.08.25 22:06, David Hildenbrand wrote: > We want to get rid of nth_page(), and kfence init code is the last user. > > Unfortunately, we might actually walk a PFN range where the pages are > not contiguous, because we might be allocating an area from memblock > that could span memory sections in problematic kernel configs (SPARSEMEM > without SPARSEMEM_VMEMMAP). > > We could check whether the page range is contiguous > using page_range_contiguous() and failing kfence init, or making kfence > incompatible these problemtic kernel configs. > > Let's keep it simple and simply use pfn_to_page() by iterating PFNs. > Fortunately this series is RFC due to lack of detailed testing :P Something gives me a NULL-pointer pointer here (maybe the virt_to_phys()). Will look into that tomorrow. -- Cheers David / dhildenb