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). 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
