On Fri, Jul 23, 2021 at 12:54:51AM +0300, Serge Semin wrote: > I always thought that ABI is supposed to be something what is > thoroughly documented and firmly declared to be so. It isn't something > claimed to be on a random nature but defined to be one when it's > more-or-less standardized. Thus the Linux kernel developers decide not > to change something unless it went through the series of iterations like > testing, stable, obsolete, remove. As I see it the rule-of-thumb is > supposed to be as "nothing is ABI unless it's declared as such". Not true at all. Again, if something works in an older kernel version, and you upgrade to a new kernel version and it breaks, that is a regression and must be fixed/reverted. Lack of documentation does not mean an ABI can be changed. greg k-h
