function::user_ulong_warn.3stap man page
function::user_ulong_warn — Retrieves an unsigned long value stored in user space
the user space address to retrieve the unsigned long from
Returns the unsigned long value from a given user space address. Returns zero when user space and warns (but does not abort) about the failure. Note that the size of the unsigned long depends on the architecture of the current user space task (for those architectures that support both 64/32 bit compat tasks).