[$] Implicit arguments for BPF kfuncs
The kernel's "kfunc" mechanism is a way of exporting kernel functions so that they can be called directly from BPF programs. There are over 300 kfuncs in current kernels, ranging in functionality from string processing (bpf_strnlen()) to custom schedulers (scx_bpf_kick_cpu()) and beyond. Sometimes these kfuncs need access to context information that is not directly available to BPF programs, and which thus cannot be passed in as arguments. The implicit arguments patch set from Ihor Solodrai is the latest attempt to solve this problem.