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b=jG3eTvVT5YX9l2V2Cv/KhMbWoHg5K7BayaSKlflwZVrDtyzpOqmr798uMpffHaVkW t+sGh8nF63T53/62Y3WwM5C0wCnJaCCWZK8uyzAedFiuCWpAKXg6CVNC7gJtKMKlqq gdW74oN/TV1drOtNakxMLWHUUhlYkkb/Aex4KXHUwHZbpmmfbtam+qnn1JiFbNJpAg YE1sZ+J7lckqrJfwKKxqhIbMhDX3Tbid0IpiRYfTHahXNzFFDImESMDGSVd2c/zd44 K2hgK9R1iDUCuxrt+OgHRkrOTE97G2DgpB3KSRTVXRr4o7d6JpI8p/UqAziMz69+Lw +slj5QIb/aheA== Message-ID: Date: Mon, 2 Mar 2026 20:08:12 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 2/3] mm/huge_memory: Prevent huge zeropage refcount corruption in PMD move To: Matthew Wilcox Cc: Chris Down , Andrew Morton , kernel-team@fb.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <6147cf80-9d02-4c5c-ab81-8cb9b00044f0@kernel.org> From: "David Hildenbrand (Arm)" 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: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: E3FAD40004 X-Rspamd-Server: rspam07 X-Stat-Signature: zx6ibjc8eg9ygr4ag9srh5u4h7xpwiwf X-Rspam-User: X-HE-Tag: 1772478497-623733 X-HE-Meta: U2FsdGVkX18DEBQ63Yno7SSEStz2QshOcCtwaD3gsJ3LbhiFPgXI5t96/TWcbEyieGxWBpgTOEJH33HFKqJT5qrsULlCb7YmBmS3RAnnMFy+YtxDFsM/cwjMM/HRDeZQIuPR6cy684JSnaOM8gcLIzTDtlRJGzzE9qoYUTGl26BEB0aZzxfENWZZLSi+PF++I3RYmQKme4sEAB6H/ENvSJiC21Jpf0OxTy2ot7QiZjSxSVzEVTY8awOjq/uTfF/SZ7lYAvC+xGqqxhD/Dby+xgVetqyXl+oW59SbG96DHBgMvRGSB9jhVH5U/ehBYVPk4amxjf2gvWyC5M87/MtNOE9e3hwRXOr1P4+kdIwRl7k1Fp5ycCLKVQQDQzCrR5l56rZ3XIJHoPceNqX/6dZIgaoeXVaBT9UPnPbdd/JLKCk+eDNPKpL0fKXMLHfDE+p8GpWsE/6EJHszcRW3DZHKYJIx8vtQy9qEcgBWzjC0csSt1mt67iIjeMlUWv1UAm0GC+CsVlXU+JNMF6mjVLfEHBR6bjHFsDkw2jlb+R1ZDQZPFEKQdZy+Sh3BF37aMGxdFxm2cUI8AcDeIRZGBF54aZr84Ye/0bkzO+h1T2hQayE1ro1Nwg9xkwhOmBuffQYUTWiLaxwzzbl/K3lOOV0VbB3AxVHWuJ7aKyBAVEZejsPObs6kLAhR32/r0Vb/eyjbXc74a0EAqeAxwKCRamwfffYVhhVJZeGcdeawr5Nw3r37+yidO6s+xiMc64QWmxozoccRwqCn7aDfDX5KSosp09ErkAnJkU2uck9kdnsbMJFhYPReNJ5kFqctvs1p0K0TIgqoQAVNRIoUfpd5Ebl8O47R+6tT7FhhOF2OlvmL2Gfjhn2FcNNPm2fQWsV1p4gzjfljhE7Wxy4Vs/zjlMOez/H8OzF0BKO2JZV4+4LrlKQ3Uf4qZaIVwzn23q7JBXGlYjDVdyLYOnRiX6LuJFD qUo/bmsI xVhCbECxNrZhxW94jqFeRUuTK2bjvC73GswJp4qfeZqTZiaUoYy+48SMZSRkGywga6B7Wm3A8pBAgPAlcAWkDQWIm7QnpL6PzRkIq67oCUVNxPoT4uLtskTzK60acOOrq/xlCrELi3lAca0EV0L1LFsq7g5msXGCy4gIuZPRyAYqK5sYnWQN1YJizZwiYAhUvtBqIbssE+ocfM9ue/S/IMLKXKRWxF5T56iuoIfq3VIwfdzdfPLRVg5QO1if3uZUWcX9zo2gM/no46QVP83pANf1DTSZipCUKbutQsEe3IlZMZm0GWPll6yT8PQ== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 3/2/26 18:42, Matthew Wilcox wrote: > On Thu, Feb 26, 2026 at 04:17:31PM +0100, David Hildenbrand (Arm) wrote: >> It doesn't make sense to leave something partially fixed in #1. It's >> been completely broken from the start. folio_mk_pmd() should never have >> been used. > > ... mk_huge_pmd() should never have been used ;-) Heh, yes! You made me grep for it and find some leftovers: arch/powerpc/mm/book3s64/pgtable.c: * pmd_mkhuge() and mk_huge_pmd() when we update all the Anybody fancy sending a cleanup? :) -- Cheers, David