On 5/25/2021 4:00 AM, Catalin Marinas wrote:
On Fri, May 21, 2021 at 03:12:10PM -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 the VMA to arch_validate_flags(), and check vma_is_anonymous(). To prepare the introduction of PROT_SHADOW_STACK, which creates a shadow stack mapping and can be applied only to an anonymous VMA, update arch_validate_flags() to pass in the VMA. [1] commit 9f3419315f3c ("arm64: mte: Add PROT_MTE support to mmap() and mprotect()"), Signed-off-by: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx>For arm64: Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Thanks!
