From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793359205; b=KgbhG9hLW5xA1VEtSTJHV9JSfsCGEj3wcTeLgQ3vFt4vGWMu9SXObQ7cEbfv2oi5N/7N CouErP0BTFq1wwmxYtJ8MGvvygvZRjUa/za26Famu/uabxV51d5+kup164AW8AGhKoPlq wA0yoAVbEkT/gVjV0M/3Qkpj3zCu/f5cxZGPXU73xA70N/wJLsgyJFdudhAzmfCpT4n2o D9xne6uQBs2bnCprY9SM77XnztoxhgeobRiZymCDcdwRgntbxd7uFAGA+wB6bt+Qk8cge 3QebzBqbD0NmFn7ezbcTarxka3fVevC6SVUKrv1EXxQD2y57WkkfQVDk+fZiWkYYqGA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793359205; h=Received:DKIM-Signature:Message-ID:Date:MIME-Version:User-Agent: Subject:From:To:Cc:References:Content-Language:Autocrypt:In-Reply-To: Content-Type:Content-Transfer-Encoding; bh=euk1MZglVLNri+rYCLQwY1lNbQIirnUyD9xcyB6Byp4=; b=dfS1eZelz0eqRK/n901Rw205U80WYdePoUErA5WYQ2leGXYWPjOylTdBqBtTgDskaXeD Pgc5whLt3FXCNGv5FhIzzxDt4qwRxaJ0H9m62kJyxP5Piy/qoMtCRgPycRxhIFoe71buQ XftW/NkMAuo/cxmmfry7FANVCBYfLZiOeNhbwZC4lk05Eos2V9ep8dyPsUnkJzlgs77tG 2Thr2R7v5D7axgkgXiAII9HeNXx0N5fgvmdO40A1xPk3DnxzYqTZRcrKQ6wYDvtwx6rM9 QSN1JoL+oHSn9za+gEdhEPhQ0fu7FsBAJ93yiZ8jewFJNefmRk0LKWlQMMgzzaDu3mg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=X8DkNBsz; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6E048606A31A; Fri, 30 Oct 2026 11:20:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=X8DkNBsz Received: by smtp.kernel.org (Postfix) with ESMTPSA id C06A81F000C1; Fri, 30 Oct 2026 11:19:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793359205; bh=euk1MZglVLNri+rYCLQwY1lNbQIirnUyD9xcyB6Byp4=; h=Date:Subject:From:To:Cc:References:In-Reply-To; b=X8DkNBszymg7DuZ6+Bhdqn9pMKv5GvRX7MN6A6XfqeofSms7pCCBsQrTGdxenLipv SfBkuCgtqgHo5NAF2TLOVZP4tnKWXJLqwO+f7RPDcBuWWPWHu+PfR17rMsqBFFNV6S lPsQnD4cT7ccl6FS6w1siLPO3V4q/J5fOE8TxFzuhxio7xGSYqO+WWbeCP+mJTlFGn VTwXQGVqR5ftMB6ScKb/G3bIbPgk9qnzJpD5jp+MtS+6lx2FFbv58ZUJDcZ7IwvteO x7JhGdArobuCUeeCxdmxzteC3/LlouaJl+KZfgJJlhmQmbmIdfM/R8yr4p1n+o8BxR 1kO0q/J2vqvrw== Message-ID: <6ac05dd8-321a-4c2e-bce8-bd7ffcac9eac@kernel.org> Date: Fri, 30 Oct 2026 12:19:46 +0100 X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 27/47] mm/mmu_gather: fix flushing ranges with 4 GiB or larger From: "David Hildenbrand (Arm)" To: SJ Park Cc: Johannes Weiner , Michal Hocko , Qi Zheng , Shakeel Butt , Lorenzo Stoakes , Kairui Song , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Baolin Wang , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kees Cook , Peter Zijlstra , Jann Horn , Pedro Falcato , Hugh Dickins , Pasha Tatashin , Pratyush Yadav , "Matthew Wilcox (Oracle)" , Jan Kara , Zi Yan , Lance Yang , Rik van Riel , Harry Yoo , Alistair Popple , Nico Pache , Ryan Roberts , Dev Jain , Usama Arif , Kiryl Shutsemau , Matthew Brost , John Hubbard , Peter Xu , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Oscar Salvador , Minchan Kim , Muchun Song , Xu Xin , Chengming Zhou , Chris Li , Kemeng Shi , Nhat Pham , Youngjun Park , Gregory Price , Joshua Hahn , Rakie Kim , Ying Huang , Jason Gunthorpe , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-cxl@vger.kernel.org, Josef Bacik , stable@vger.kernel.org References: <20261030005726.155279-1-sj@kernel.org> <48a66134-3522-4b81-adca-4e76d52dc391@kernel.org> Content-Language: en-US Autocrypt: addr=david@kernel.org; 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 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+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: <48a66134-3522-4b81-adca-4e76d52dc391@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 10/30/26 12:15, David Hildenbrand (Arm) wrote: > On 10/30/26 01:57, SJ Park wrote: >> On Thu, 29 Oct 2026 21:33:22 +0100 "David Hildenbrand (Arm)" wrote: >> >>> From: Josef Bacik >>> >>> __tlb_adjust_range() takes the size of the range which has to be flushed >>> as an unsigned int. Its callers, tlb_flush_{pte,pmd,pud,p4d}_range(), get >>> and pass an unsigned long. Consequently, a range that is 4 GiB or larger >>> gets truncated, possibly to 0. >>> >>> On arm64 with hugetlb, a 64k kernel can have 16 GiB hugetlb folios >>> mapped contiguously at the PMD level and flush them when unmapping, and a >>> 16k kernel can flush 64 GiB PUDs through tlb_unshare_pmd_ptdesc(). So >>> at least these two scenarios are affected. >>> >>> Fix it by flushing the proper range instead of the truncated one by >>> properly using "unsigned long" for range_size. >> >> Makes sense to me. >> >>> >>> Fix generated by an LLM and sent by Josef Bacik in private. >>> >>> Fixes: b528e4b6405b ("mm/hugetlb: add tlb_remove_hugetlb_entry for handling hugetlb pages") >>> Fixes: 8ce720d5bd91 ("mm/hugetlb: fix excessive IPI broadcasts when unsharing PMD tables using mmu_gather") >>> Cc: stable@vger.kernel.org >>> Signed-off-by: Josef Bacik >>> Acked-by: Lorenzo Stoakes (ARM) >>> [ david: use two-tab indent, simplify description ] >> >> It seems the convention [1] is to put the above modification note right before >> the last S-o-b: of David. Maybe you forgot moving it after adding R-b: and >> T-b: from great reviewers? > > It's "b4 trailers" that apparently messes this up. I don't think it really > matters (some move it above all trailers), but I'll fix this up when applying. Thinking again, I *think* this order is correct. People reviewed and tested with these changes. it would be something different if I modify a patch while applying it. Because then, what people reviewed and tested would be different to the original version. -- Cheers, David