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References: <202112041334.X44uWZXf-lkp@intel.com>
In-Reply-To: <202112041334.X44uWZXf-lkp@intel.com>
From:   Marco Elver <elver@google.com>
Date:   Sat, 4 Dec 2021 14:02:33 +0100
Message-ID: <CANpmjNOpoYrgk85hsOroh67TqUPtawWCnbk1GwqdUnGEKrOP+w@mail.gmail.com>
Subject: Re: [paulmck-rcu:dev.2021.12.02a 31/43] include/asm-generic/barrier.h:70:30:
 warning: 'kcsan_rmb' is static but used in inline function
 'pte_offset_kernel' which is not static
To:     kernel test robot <lkp@intel.com>
Cc:     kbuild-all@lists.01.org, linux-kernel@vger.kernel.org,
        "Paul E. McKenney" <paulmck@kernel.org>
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On Sat, 4 Dec 2021 at 06:33, kernel test robot <lkp@intel.com> wrote:
[...]
> >> include/asm-generic/barrier.h:70:30: warning: 'kcsan_rmb' is static but used in inline function 'pte_offset_kernel' which is not static
>       70 | #define smp_rmb()       do { kcsan_rmb(); __smp_rmb(); } while (0)
>          |                              ^~~~~~~~~
>    arch/alpha/include/asm/pgtable.h:303:9: note: in expansion of macro 'smp_rmb'
>      303 |         smp_rmb(); /* see above */
>          |         ^~~~~~~
> >> include/asm-generic/barrier.h:70:30: warning: 'kcsan_rmb' is static but used in inline function 'pmd_offset' which is not static
>       70 | #define smp_rmb()       do { kcsan_rmb(); __smp_rmb(); } while (0)
>          |                              ^~~~~~~~~
>    arch/alpha/include/asm/pgtable.h:293:9: note: in expansion of macro 'smp_rmb'
>      293 |         smp_rmb(); /* see above */
>          |         ^~~~~~~

I had been wondering if barriers could be static __always_inline, like
we do for atomic_t operations. Apparently this answers that questions.

This should fix it:
https://lkml.kernel.org/r/20211204125703.3344454-1-elver@google.com

Unrelatedly, I wonder if I can get the test robot to also check some
of my branches:
https://git.kernel.org/pub/scm/linux/kernel/git/melver/linux.git/
That'd be very useful, to catch things like this early, and avoid
disturbing Paul too much. :-)

Thanks,
-- Marco