Re: kbuild problem: ERROR: modpost: missing MODULE_LICENSE() in drivers/iio/afe/iio-rescale.o

[Masahiro Yamada]

On Sat, May 21, 2022 at 11:40 AM Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote:
>
> Hi,
>
> In March I reported that a randconfig build complained:
>
> ERROR: modpost: missing MODULE_LICENSE() in drivers/iio/afe/iio-rescale.o
>
> (https://lore.kernel.org/all/16509fb6-e40c-e31b-2c80-264c44b0beb9@xxxxxxxxxxxxx/)
>
> I am still seeing this problem so I tried to dig into it a bit.
> However, I don't see why get_next_modinfo() and friends don't find the
> MODULE_LICENSE() since it is in the iio-rescale.o file.
>
> (BTW, I see this build error on many different $ARCH [around 15 tested]
> and with 2 different versions of GCC.)
>
> Q1: Is modpost checking both vmlinux and iio-rescale.o for modinfo license
> strings?


MODULE_LICENSE() is no-op for vmlinux.

modpost checks this only for modules.



>
> It looks like it is, because it appears (?) that modpost is looking at
> drivers/iio/test/iio-test-rescale.o (<<<<< a kunit test, which is builtin
> in my .config) and at drivers/iio/afe/iio-rescale.o (which is built as a
> loadable module).
>
> Is this confusing modpost?
> I renamed drivers/iio/afe/iio-rescale.c to afe-rescale.c and changed its
> Makefile entry accordingly and the MODULE_LICENSE error goes away.
>
> Is this a modpost error or is kunit messing things up?
>
> thanks for looking.
> --
> ~Randy



-- 
Best Regards
Masahiro Yamada