On Mon, Nov 09, 2020 at 09:44:02AM +0100, Thomas Hellström wrote: > static inline bool vma_is_special_huge(const struct vm_area_struct > *vma) > { > return vma_is_dax(vma) || (vma->vm_file && > (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))); > } That is testing a VMA, not a PTE, which doesn't help protect get_user_pages_fast. Sounds like is has opened a big user crashy problem in DRM and the huge page stuff needs to be revereted.. Dan? Jason