[PATCH v19 00/15] arm64: untag user pointers passed to the kernel

[Dave Hansen]

On 7/23/19 10:58 AM, Andrey Konovalov wrote:
> The mmap and mremap (only new_addr) syscalls do not currently accept
> tagged addresses. Architectures may interpret the tag as a background
> colour for the corresponding vma.

What the heck is a "background colour"? :)