On Thu, Apr 15, 2021 at 03:14:18PM -0700, Yu-cheng Yu wrote: > When newer VM flags are being created, such as VM_MTE, it becomes necessary > for mmap/mprotect to verify if certain flags are being applied to an > anonymous VMA. > > To solve this, one approach is adding a VM flag to track that MAP_ANONYMOUS > is specified [1], and then using the flag in arch_validate_flags(). > > Another approach is passing vma_is_anonymous() to arch_validate_flags(). > To prepare the introduction of PROT_SHSTK, which creates a shadow stack > mapping and can only be applied to an anonymous VMA, update arch_validate_ > flags() to include anonymous VMA information. I would rather pass down whole vma. Who knows what else arch_validate_flags() would need to know about the VMA tomorrow: arch_validate_flags(vma, newflags); should do the trick. -- Kirill A. Shutemov
