On Thu, Feb 04, 2021 at 08:26:04AM +0100, Jiri Slaby wrote: > On 04. 02. 21, 7:20, Greg Kroah-Hartman wrote: > > On Thu, Feb 04, 2021 at 05:59:42AM +0000, Jari Ruusu wrote: > > > Greg, > > > I hope that your linux kernel release scripts are > > > implemented in a way that understands that PATCHLEVEL= and > > > SUBLEVEL= numbers in top-level linux Makefile are encoded > > > as 8-bit numbers for LINUX_VERSION_CODE and > > > KERNEL_VERSION() macros, and must stay in range 0...255. > > > These 8-bit limits are hardcoded in both kernel source and > > > userspace ABI. > > > > > > After 4.9.255 and 4.4.255, your scripts should be > > > incrementing a number in EXTRAVERSION= in top-level > > > linux Makefile. > > > > Should already be fixed in linux-next, right? > > I assume you mean: > commit 537896fabed11f8d9788886d1aacdb977213c7b3 > Author: Sasha Levin <sashal@xxxxxxxxxx> > Date: Mon Jan 18 14:54:53 2021 -0500 > > kbuild: give the SUBLEVEL more room in KERNEL_VERSION > > That would IMO break userspace as definition of kernel version has changed. > And that one is UAPI/ABI (see include/generated/uapi/linux/version.h) as > Jari writes. For example will glibc still work: > http://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/unix/sysv/linux/configure.ac;h=13abda0a51484c5951ffc6d718aa36b72f3a9429;hb=HEAD#l14 > > ? Or gcc 10 (11 will have this differently): > https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/config/bpf/bpf.c;hb=ee5c3db6c5b2c3332912fb4c9cfa2864569ebd9a#l165 > > and > > https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/config/bpf/bpf-helpers.h;hb=ee5c3db6c5b2c3332912fb4c9cfa2864569ebd9a#l53 Ugh, I thought this was an internal representation, not an external one :( > It might work somewhere, but there are a lot of (X * 65536 + Y * 256 + Z) > assumptions all around the world. So this doesn't look like a good idea. Ok, so what happens if we "wrap"? What will break with that? At first glance, I can't see anything as we keep the padding the same, and our build scripts seem to pick the number up from the Makefile and treat it like a string. It's only the crazy out-of-tree kernel stuff that wants to do minor version checks that might go boom. And frankly, I'm not all that concerned if they have problems :) So, let's leave it alone and just see what happens! greg k-h
