This document describes the implementation of the SystemTap Runtime. It is intended for developers of the SystemTap Language translator, TapSet authors or kprobes programmers. These functions are not directly available from the SystemTap Language.
The SystemTap Runtime Library consists of all functions and code fragments needed by the compiler/translator to include in building a kernel module using kprobes. It also includes I/O code to transmit its output from the kernel to userspace.
In addition to the library, the runtime includes a SystemTap user-space daemon (staprun). Staprun grabs data sent from the I/O code in the runtime and displays it and/or saves it to files. Staprun will handle other issues like inserting and removing modules.
Staprun and the I/O code makes use of /proc (and optionally relayfs) for communications. For kernels without relayfs builtin, it is provided as a standalone module under the runtime directory.