function::uaddr.3stap man page
function::uaddr — User space address of current running task
Returns the address in userspace that the current task was at when the probe occurred. When the current running task isn't a user space thread, or the address cannot be found, zero is returned. Can be used to see where the current task is combined with usymname or usymdata. Often the task will be in the VDSO where it entered the kernel.