Dne 24.11.2016 v 11:03 Nicholas Piggin napsal(a): > On Thu, 24 Nov 2016 10:32:12 +0100 > Michal Marek <mmarek@xxxxxxxx> wrote: > >> On 2016-11-24 08:53, Nicholas Piggin wrote: >>> On Thu, 24 Nov 2016 08:36:39 +0100 >>> Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: >>> >>>> On Thu, Nov 24, 2016 at 06:20:26PM +1100, Nicholas Piggin wrote: >>>>> But still, modversions is pretty complicated for what it gives us. It sends >>>>> preprocessed C into a C parser that makes CRCs using type definitions of >>>>> exported symbols, then turns those CRCs into a linker script which which is >>>>> used to link the .o file with. What we get in return is a quite limited and >>>>> symbol "versioning" system. >>>>> >>>>> What if we ripped all that out and just attached an explicit version to >>>>> each export, and incompatible changes require an increment? >>>> >>>> How would that work for structures? Would that be required for every >>>> EXPORT_SYMBOL* somehow? >>> >>> Yeah just have EXPORT_SYMBOL take another parameter which attaches a version >>> number and use that as the value for the __crc_ symbol versions rather than >>> a calculated CRC. >> >> The problem is that with every kernel release, the structures change in >> a way that you would have to bump the version of virtually every export. >> >> At which point, there would be little difference between >> CONFIG_MODVERSION on and off (without CONFIG_MODVERSION, we compare the >> kernel version strings when loading modules). > > > I'm not sure about that. If they are truly incompatible changes and > MODVERSIONS does not pick up a different CRC, then it's even worse if > incompatible modules are missed so often. Now I'm confused: Are you suggesting to do this manual symbol versioning for all exports, or only those defined in asm? Thanks, Michal -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
