Post Syndicated from corbet original https://lwn.net/Articles/1005662/

A “uretprobe” is a dynamic, user-space tracepoint injected by the kernel
into a running process; this document
tersely describes their use. Among other things, uretprobes are used by
the perf utility to time function calls. The 6.11 kernel saw a
significant change to uretprobes that improved their performance, but that
change is also creating trouble for some users. The best way to solve the
problem is not entirely clear.