bpf_probe_read can't read user space data

I am writing a script to fetch user function's argument using uprobe. When I use bpf_probe_read_user in high version linux 5.0+, I succeed. But when I use linux 4.19, I find that there is no bpf_probe_read_user existing. Only bpf_probe_read can use. Then I tried this function, it can read kernel space data, but can't read user space data. Error code is -14. Are there any way to read user space data in 4.19 version linux?

Start with the uprobe use of bpf_probe_read_user and bpf_probe_read on Linux 4.19, then compare helper availability and error -14 with Linux 5.0 behavior. Done means establishing a supported 4.19 approach or documenting that this kernel version cannot read the requested user-space data.

Written by the indexing model from the issue text.