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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 10.06.25 15:24, David Hildenbrand wrote: > On 10.06.25 14:07, Lorenzo Stoakes wrote: >> OK so I think the best solution here is to just update check_ops_valid(), which >> was kind of sucky anyway (we check everywhere but walk_page_range_mm() to >> enforce the install pte thing). >> >> Let's do something like: >> >> #define OPS_MAY_INSTALL_PTE (1<<0) >> #define OPS_MAY_AVOID_LOCK (1<<1) >> >> and update check_ops_valid() to take a flags or maybe 'capabilities' field. >> >> Then check based on this e.g.: >> >> if (ops->install_pte && !(capabilities & OPS_MAY_INSTALL_PTE)) >> return false; >> >> if (ops->walk_lock == PGWALK_NOLOCK && !(capabilities & OPS_MAY_AVOID_LOCK)) >> return false; >> > > Hm. I mean, we really only want to allow this lockless check for > walk_kernel_page_table_range(), right? > > Having a walk_kernel_page_table_range_lockeless() might (or might not) > be better, to really only special-case this specific path. Note that I am also not quite happy bout that function name, but I think we should add a proper interface that documents clearly when it is even okay to call that function ... -- Cheers, David / dhildenb