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Date:   Fri, 20 May 2022 19:40:26 -0700
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To:     Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
        Masahiro Yamada <masahiroy@kernel.org>
Cc:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        linux-iio@vger.kernel.org, Peter Rosin <peda@axentia.se>,
        "open list:KERNEL SELFTEST FRAMEWORK" 
        <linux-kselftest@vger.kernel.org>,
        KUnit Development <kunit-dev@googlegroups.com>
From:   Randy Dunlap <rdunlap@infradead.org>
Subject: kbuild problem: ERROR: modpost: missing MODULE_LICENSE() in
 drivers/iio/afe/iio-rescale.o
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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@infradead.org/)

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?

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