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Howlett" , dave.hansen@linux.intel.com, kirill.shutemov@linux.intel.com, Shakeel Butt , SeongJae Park , David Hildenbrand , Lorenzo Stoakes , Vlastimil Babka , Andrew Morton , Jens Axboe , Pavel Begunkov , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Ryan Roberts References: From: Dave Hansen Content-Language: en-US Autocrypt: addr=dave.hansen@intel.com; keydata= xsFNBE6HMP0BEADIMA3XYkQfF3dwHlj58Yjsc4E5y5G67cfbt8dvaUq2fx1lR0K9h1bOI6fC oAiUXvGAOxPDsB/P6UEOISPpLl5IuYsSwAeZGkdQ5g6m1xq7AlDJQZddhr/1DC/nMVa/2BoY 2UnKuZuSBu7lgOE193+7Uks3416N2hTkyKUSNkduyoZ9F5twiBhxPJwPtn/wnch6n5RsoXsb ygOEDxLEsSk/7eyFycjE+btUtAWZtx+HseyaGfqkZK0Z9bT1lsaHecmB203xShwCPT49Blxz VOab8668QpaEOdLGhtvrVYVK7x4skyT3nGWcgDCl5/Vp3TWA4K+IofwvXzX2ON/Mj7aQwf5W iC+3nWC7q0uxKwwsddJ0Nu+dpA/UORQWa1NiAftEoSpk5+nUUi0WE+5DRm0H+TXKBWMGNCFn c6+EKg5zQaa8KqymHcOrSXNPmzJuXvDQ8uj2J8XuzCZfK4uy1+YdIr0yyEMI7mdh4KX50LO1 pmowEqDh7dLShTOif/7UtQYrzYq9cPnjU2ZW4qd5Qz2joSGTG9eCXLz5PRe5SqHxv6ljk8mb ApNuY7bOXO/A7T2j5RwXIlcmssqIjBcxsRRoIbpCwWWGjkYjzYCjgsNFL6rt4OL11OUF37wL QcTl7fbCGv53KfKPdYD5hcbguLKi/aCccJK18ZwNjFhqr4MliQARAQABzUVEYXZpZCBDaHJp c3RvcGhlciBIYW5zZW4gKEludGVsIFdvcmsgQWRkcmVzcykgPGRhdmUuaGFuc2VuQGludGVs LmNvbT7CwXgEEwECACIFAlQ+9J0CGwMGCwkIBwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEGg1 lTBwyZKwLZUP/0dnbhDc229u2u6WtK1s1cSd9WsflGXGagkR6liJ4um3XCfYWDHvIdkHYC1t MNcVHFBwmQkawxsYvgO8kXT3SaFZe4ISfB4K4CL2qp4JO+nJdlFUbZI7cz/Td9z8nHjMcWYF IQuTsWOLs/LBMTs+ANumibtw6UkiGVD3dfHJAOPNApjVr+M0P/lVmTeP8w0uVcd2syiaU5jB aht9CYATn+ytFGWZnBEEQFnqcibIaOrmoBLu2b3fKJEd8Jp7NHDSIdrvrMjYynmc6sZKUqH2 I1qOevaa8jUg7wlLJAWGfIqnu85kkqrVOkbNbk4TPub7VOqA6qG5GCNEIv6ZY7HLYd/vAkVY E8Plzq/NwLAuOWxvGrOl7OPuwVeR4hBDfcrNb990MFPpjGgACzAZyjdmYoMu8j3/MAEW4P0z F5+EYJAOZ+z212y1pchNNauehORXgjrNKsZwxwKpPY9qb84E3O9KYpwfATsqOoQ6tTgr+1BR CCwP712H+E9U5HJ0iibN/CDZFVPL1bRerHziuwuQuvE0qWg0+0SChFe9oq0KAwEkVs6ZDMB2 P16MieEEQ6StQRlvy2YBv80L1TMl3T90Bo1UUn6ARXEpcbFE0/aORH/jEXcRteb+vuik5UGY 5TsyLYdPur3TXm7XDBdmmyQVJjnJKYK9AQxj95KlXLVO38lczsFNBFRjzmoBEACyAxbvUEhd GDGNg0JhDdezyTdN8C9BFsdxyTLnSH31NRiyp1QtuxvcqGZjb2trDVuCbIzRrgMZLVgo3upr MIOx1CXEgmn23Zhh0EpdVHM8IKx9Z7V0r+rrpRWFE8/wQZngKYVi49PGoZj50ZEifEJ5qn/H Nsp2+Y+bTUjDdgWMATg9DiFMyv8fvoqgNsNyrrZTnSgoLzdxr89FGHZCoSoAK8gfgFHuO54B lI8QOfPDG9WDPJ66HCodjTlBEr/Cwq6GruxS5i2Y33YVqxvFvDa1tUtl+iJ2SWKS9kCai2DR 3BwVONJEYSDQaven/EHMlY1q8Vln3lGPsS11vSUK3QcNJjmrgYxH5KsVsf6PNRj9mp8Z1kIG qjRx08+nnyStWC0gZH6NrYyS9rpqH3j+hA2WcI7De51L4Rv9pFwzp161mvtc6eC/GxaiUGuH BNAVP0PY0fqvIC68p3rLIAW3f97uv4ce2RSQ7LbsPsimOeCo/5vgS6YQsj83E+AipPr09Caj 0hloj+hFoqiticNpmsxdWKoOsV0PftcQvBCCYuhKbZV9s5hjt9qn8CE86A5g5KqDf83Fxqm/ vXKgHNFHE5zgXGZnrmaf6resQzbvJHO0Fb0CcIohzrpPaL3YepcLDoCCgElGMGQjdCcSQ+Ci FCRl0Bvyj1YZUql+ZkptgGjikQARAQABwsFfBBgBAgAJBQJUY85qAhsMAAoJEGg1lTBwyZKw l4IQAIKHs/9po4spZDFyfDjunimEhVHqlUt7ggR1Hsl/tkvTSze8pI1P6dGp2XW6AnH1iayn yRcoyT0ZJ+Zmm4xAH1zqKjWplzqdb/dO28qk0bPso8+1oPO8oDhLm1+tY+cOvufXkBTm+whm +AyNTjaCRt6aSMnA/QHVGSJ8grrTJCoACVNhnXg/R0g90g8iV8Q+IBZyDkG0tBThaDdw1B2l asInUTeb9EiVfL/Zjdg5VWiF9LL7iS+9hTeVdR09vThQ/DhVbCNxVk+DtyBHsjOKifrVsYep WpRGBIAu3bK8eXtyvrw1igWTNs2wazJ71+0z2jMzbclKAyRHKU9JdN6Hkkgr2nPb561yjcB8 sIq1pFXKyO+nKy6SZYxOvHxCcjk2fkw6UmPU6/j/nQlj2lfOAgNVKuDLothIxzi8pndB8Jju KktE5HJqUUMXePkAYIxEQ0mMc8Po7tuXdejgPMwgP7x65xtfEqI0RuzbUioFltsp1jUaRwQZ MTsCeQDdjpgHsj+P2ZDeEKCbma4m6Ez/YWs4+zDm1X8uZDkZcfQlD9NldbKDJEXLIjYWo1PH hYepSffIWPyvBMBTW2W5FRjJ4vLRrJSUoEfJuPQ3vW9Y73foyo/qFoURHO48AinGPZ7PC7TF vUaNOTjKedrqHkaOcqB185ahG2had0xnFsDPlx5y In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 24ACA40008 X-Rspam-User: X-Rspamd-Server: rspam07 X-Stat-Signature: boi3r6p87jqkoefidp7q8zsoj9gys8ck X-HE-Tag: 1736885732-820716 X-HE-Meta: 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 LN3+1zSZ U3MEQbUDKmNF2Vczi5V2pZnjiU1GyzqNDSOBV6QZqQk3l90xU9Xg5ItXiy6LI6dIUGyVBd1cXEM/GATt2JvDhAgKRNxr6HTbpgVc0x6p3fFG3aYIny7wKVBPvoW4Vhmk8XQPVfpybaeEYileGwk25Juzk+5shxNcvtNnO3bdVMWcKfE9luof78PZKrGViQ+3Ae8uQmN8aP5fukLo0+ewNzQV7OOB0WQJ6FDsP1LHjJ11/tMmAslYMmpDN2Rfz/sH2JWpvh2oFSCvXzSePTsMzY5cZ26AyRk78XUatsQdh9sSAavGkEuB0AKgAeufvZAvBX0kfXb+/lmTRmjU= 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 1/14/25 11:43, Liam R. Howlett wrote: > Can anyone tell me why the code today is correct? That is, how can we > trust the validation of start/end is still okay after we change the > start/end by untagging the start? Well, let's walk through the start/end validation. First: if (!PAGE_ALIGNED(start)) return -EINVAL; That should stay valid as long as the tag/untag doesn't affect the lower bits. All the tagging is upper bits that are far away from the