DESCRIPTION

The uprobes kernel facility introduced in Linux 3.5 aims to supplant the earlier out-of-tree utrace patch to enable user-space probing. There have been some functional limitations in inode-uprobes that preclude some systemtap constructs. Over time, we hope these regressions will be corrected.

function.return probes

process.function().return probes require "return-probes" or "uretprobes" functionality, which was not implemented in the builtin inode-uprobes until kernel 3.10. If you cannot upgrade your kernel, consider using process.statement() probes placed on source line numbers at the function's return statements.

function.statement.absolute probes

In utrace-equipped kernels, systemtap made it possible to address probes by literal addresses in the process virtual memory address space. The new inode-uprobes does not have this capability.