On Wed, Nov 6, 2024 at 10:27 PM Lucas De Marchi <lucas.demarchi@xxxxxxxxx> wrote: > > On Wed, Nov 06, 2024 at 02:19:38PM -0800, Matthew Maurer wrote: > >> > >> > If booted against an old kernel, it will > >> > behave as though there is no modversions information. > >> > >> Huh? This I don't get. If you have the new libkmod and boot > >> an old kernel, that should just not break becauase well, long > >> symbols were not ever supported properly anyway, so no regression. > > > >Specifically, if you set NO_BASIC_MODVERSIONS, build a module, and > > how are you setting NO_BASIC_MODVERSIONS and loading it in a kernel > that still doesn't have that, i.e. before EXTENDED_MODVERSIONS? That action would involve e.g. building a module against a 6.13 series kernel with NO_BASIC_MODVERSIONS and trying insmod it on a 6.12 series kernel. I know it's not supported, I was just trying to describe the full matrix of what would happen differently with the proposed additional config flag. > > Please Cc me on the format change and if possible submit the libkmod > support. It seems awkward to adjust kmod to support a format that still hasn't been accepted to the kernel. I can send kmod patches to support it, but since this patch series hasn't been accepted yet, it seemed a bit premature. I'll explicitly add you to the format change (patch before this in the series) and add you to the whole series in v9 > > thanks > Lucas De Marchi > > >then load said module with a kernel *before* EXTENDED_MODVERSIONS > >existed, it will see no modversion info on the module to check. This > >will be true regardless of symbol length. > > > >> > >> I'm not quite sure I understood your last comment here though, > >> can you clarify what you meant? > >> > >> Anyway, so now that this is all cleared up, the next question I have > >> is, let's compare a NO_BASIC_MODVERSIONS world now, given that the > >> userspace requirements aren't large at all, what actual benefits does > >> using this new extended mod versions have? Why wouldn't a distro end > >> up preferring this for say a future release for all modules? > > > >I think a distro will end up preferring using this for all modules, > >but was intending to put both in for a transitional period until the > >new format was more accepted. > > > >> > >> Luis
