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Peter Anvin" , Alexander Potapenko , Marco Elver , Dmitry Vyukov , Andrew Morton , Kairui Song , Qi Zheng , Shakeel Butt , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Baolin Wang , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kees Cook Cc: Borislav Petkov , linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, Ilya Leoshkevich References: <20261101-kmsan-serie-v2-0-f97f66dc57ef@gmail.com> <20261101-kmsan-serie-v2-3-f97f66dc57ef@gmail.com> 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: <20261101-kmsan-serie-v2-3-f97f66dc57ef@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: D030EA0003 X-Stat-Signature: bnrn6r7maxwbdbjpyehkaitiordd1snu X-Spam-Status: No, score=-12.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=4.0.1 X-Rspam-User: X-Rspamd-Server: rspam09 X-HE-Tag: 1793556193-972243 X-HE-Meta: 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 u24MUX0f BVo5me8nUChBukBdutzEa4X6O2R1Dvmp3icFtAHLJlrQhGmilfWCwfigmJow8wdTsNAuqi06YwtPkgDMr6HQgPQnaB+Oj5azil7fOlcICcly0zhtuhbn9lJt2nTzWU1rdL/LNOiIdB+WedUWHkhxyOjrc8kubKRfYpzcLWWRmiaBhV850rH/AFaseYm/WST86qJIXYFasySrim2wtD8YOYiiw326i70qziEn8V1vyQKoeF14hl0llQkyOY3czEdeMvYjymngo3VIlT1bkWI72ZelvUe5ipNUhSRQIwLfILExDQdSdrhpN33hTLIjdiIgfaN2R9NrlgXNhf5VzlW2fuiQmJsS1xa+PyKX/wx0epnfA/nZ5P8BgdeAB1hgjmk844+AO Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On 11/1/26 18:04, Viorel Cernateanu via B4 Relay wrote: > From: Viorel Cernateanu > > KMSAN needs to validate a PFN during metadata lookup without entering > instrumented code. Calling pfn_valid() also calls > rcu_read_lock_sched(), which can enter instrumented code and recurse > into the metadata lookup. > > Extract the PFN checks into __pfn_valid(), whose caller must already > be in an RCU-sched read-side critical section. Keep pfn_valid() as > the wrapper that acquires and releases that protection. > > This lets KMSAN reuse the existing PFN validation while providing > the required protection without instrumented helpers. > > The wrapper now also holds the RCU-sched read lock during the > initial range checks, which previously ran before acquiring it. > > Suggested-by: Alexander Potapenko > Signed-off-by: Viorel Cernateanu > --- Acked-by: David Hildenbrand (Arm) -- Cheers, David