Post Syndicated from original https://lwn.net/Articles/917052/

Alison Chaiken provides an
overview of Linux ABI concerns on opensource.com.

Understanding the stable ABI is a bit subtle. Consider that, while
most of sysfs is stable ABI, the debug interfaces are guaranteed to
be unstable since they expose kernel internals to userspace. In
general, Linus Torvalds has pronounced that by “don’t break
userspace,” he means to protect ordinary users who “just want it to
work” rather than system programmers and kernel engineers, who
should be able to read the kernel documentation and source code to
figure out what has changed between releases.