What is KABI or (Kernel ABI) ?

• ABIs are similar to APIs in that they govern the interpretation of commands and exchange of binary data.

• For C programs, the ABI generally comprises the return types and parameter lists of functions, the layout of structs, and the meaning, ordering, and range of enumerated types.

• The functionality of the ABI requires a joint, ongoing effort by :

  • the kernel community, C compilers (such as GCC or clang),

  • the developers who create the userspace C library (most commonly glibc) that implements system calls, and binary applications, which much be laid out in accordance with the Executable and Linking Format (ELF) - All of sysfs (/sys) and procfs (/proc) are guaranteed stable except for /sys/kernel/debug
• Syscall interface is also guaranteed to be stable

Reference : https://opensource.com/article/22/12/linux-abi Linus on ABI Breakage : https://lkml.org/lkml/2018/12/22/232