Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> writes: > Since commit "modpost: do not set ->preloaded for symbols from > Module.symvers", the modpost always warns about symbols exported > multiple times. > > Generally, I believe it is a good thing to show a warning when the > same symbol name is exported twice. This avoids the accidental symbol > conflict. > > However, in some cases, we build an external module to provide a > different version/variant of the in-kernel module, overriding the > same set of exported symbols. > > At least, there is one use-case in the upstream code; > tools/testing/nvdimm/libnvdimm.ko replaces drivers/nvdimm/libnvdimm.ko > in order to link it against mocked version of core kernel symbols. > > Now, this emits a lots of 'exported twice' warnings: > > https://lkml.org/lkml/2019/10/31/627 > > To suppress those, add a new option KBUILD_DUPLICATED_EXPORTS_NO_WARN. > > If you intentionally override the existing symbols, you can pass it > from the command line: > > make M=tools/testing/nvdimm KBUILD_DUPLICATED_EXPORTS_NO_WARN=1 > > Or, more conveniently, you can add it to the module Makefile, so > you can still do: > > make M=tools/testing/nvdimm > > without sprinkling the warnings. > > Reported-by: Jeff Moyer <jmoyer@xxxxxxxxxx> > Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> > --- > > Jeff Moyer, > Dan Williams, > > Please check if this patch solves the nvdimm build issue. Yep, that fixes it for me. You can add: Tested-by: Jeff Moyer <jmoyer@xxxxxxxxxx> Thanks!
