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[80.187.83.189]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-46fb482b9absm200025705e9.2.2025.10.13.02.54.01 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 13 Oct 2025 02:54:02 -0700 (PDT) Message-ID: Date: Mon, 13 Oct 2025 11:54:00 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4] hugetlbfs: check for shareable lock before calling huge_pmd_unshare() To: Deepanshu Kartikey , muchun.song@linux.dev, osalvador@suse.de, akpm@linux-foundation.org, broonie@kernel.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, syzbot+f26d7c75c26ec19790e7@syzkaller.appspotmail.com References: <20251013093337.4432-1-kartikey406@gmail.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 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: <20251013093337.4432-1-kartikey406@gmail.com> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: SzBDfG20a5-jzNA4ujFu5ulWYeJMuz6w2wduQEZ6oG8_1760349243 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Stat-Signature: eowfynsz6r563ctgbgzqzn61bjb6izbf X-Rspamd-Queue-Id: 96F5CC0009 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1760349246-394229 X-HE-Meta: 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 owUYbaHn 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 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 13.10.25 11:33, Deepanshu Kartikey wrote: > Hi David, > > That makes a lot of sense - moving the assertions after the early return > checks is cleaner since the locks are only needed when actual unsharing > work happens. > > Should I send a v5 with your suggested change? Let's wait if the hugetlb maintainers have any preference. -- Cheers David / dhildenb