Can current macro be accessed from interrupt context?

["Leonidas ." <leonidas137@gmail.com>]

Hello,

Going through UTLK, it says that current macro makes sense only in
case of process context,
in case of interrupt context it is invalid.

But current would still be pointing to interrupted process right? The
pointer would still be valid?
Can I safely assume that whether or not interrupt handlers are
executing on separate stacks or
interrupted threads stack, current macro can be accessed from interrupt context?

My use case is to get process id from any context with CONFIG_4KSTACKS = 0 or 1.

Any pointers will be helpful.
-Leo.