On Wed, Apr 27, 2022 at 1:40 AM Nick Desaulniers <ndesaulniers@xxxxxxxxxx> wrote: > > On Mon, Apr 25, 2022 at 9:10 PM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote: > > > > On Tue, Apr 26, 2022 at 3:48 AM Nick Desaulniers > > <ndesaulniers@xxxxxxxxxx> wrote: > > > > > > On Sun, Apr 24, 2022 at 12:09 PM Masahiro Yamada <masahiroy@xxxxxxxxxx> wrote: > > > > > > > > This is currently a warning, but I think modpost should stop building > > > > in this case. > > > > > > > > If the same symbol is exported multiple times and we let it keep going, > > > > the sanity check becomes difficult. > > > > > > > > Only the legitimate case is that an external module overrides the > > > > corresponding in-tree module to provide a different implementation > > > > with the same interface. > > > > > > Could the same module export a weak version of a symbol, and a strong one? > > > > No. There is no concept like EXPORT_SYMBOL_WEAK. > > > > I am talking about kmod things. > > You can modprobe an external module instead of the in-kernel one. > > Ok, this patch seems fine to me. > Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > -- > Thanks, > ~Nick Desaulniers Nick, If useful, I can add more commits to the commit description. I know one example in the tree that exploits this feature. $ make allmodconfig all You will get drivers/nvdimm/libnvdimm.ko, then $ make M=tools/testing/nvdimm You will get tools/testing/nvdimm/libnvdimm.ko The latter is a mocked one that exported the same symbols as drivers/nvdimm/libnvdimm.ko -- Best Regards Masahiro Yamada
