On Fri, Feb 05, 2021 at 12:56:58PM -0800, Guenter Roeck wrote: > 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 ? I think Sasha's patch here: https://lore.kernel.org/r/20210205174702.1904681-1-sashal@xxxxxxxxxx is looking like the solution. thanks, greg k-h
