On Fri, Feb 05, 2021 at 03:26:36PM +0100, Greg Kroah-Hartman wrote: > I'm announcing the release of the 4.4.256 kernel. > > This, and the 4.9.256 release are a little bit "different" than normal. > > This contains only 1 patch, just the version bump from .255 to .256 which ends > up causing the userspace-visable LINUX_VERSION_CODE to behave a bit differently > than normal due to the "overflow". > > With this release, KERNEL_VERSION(4, 4, 256) is the same as KERNEL_VERSION(4, 5, 0). > > Nothing in the kernel build itself breaks with this change, but given that this > is a userspace visible change, and some crazy tools (like glibc and gcc) have > logic that checks the kernel version for different reasons, I wanted to do this > release as an "empty" release to ensure that everything still works properly. > > So, this is a YOU MUST UPGRADE requirement of a release. If you rely on the > 4.4.y kernel, please throw this release into your test builds and rebuild the > world and let us know if anything breaks, or if all is well. > > Go forth and do full system rebuilds! Yocto and Gentoo are great for this, as > will systems that use buildroot. > > I'll try to hold off on doing a "real" 4.4.y release for a week to give > everyone a chance to test this out and get back to me. The pending patches in > the 4.4.y queue are pretty serious, so I am loath to wait longer than that, > consider yourself warned... > Thanks a lot for the heads-up. For chromeos-4.4, the version number wrap is indeed fatal: Unfortunately we have lots of vendor code in the tree which uses KERNEL_VERSION(), and all the version comparisons against KERNEL_VERSION(4,5,0) do result in compile errors. The best workaround/hack/kludge to address the problem seems to be the idea to use 4.4.255 as version number for LINUX_VERSION_CODE and KERNEL_VERSION() if SUBLEVEL is larger than 255. Did anyone find a better solution for the problem ? Thanks, Guenter
