Re: [PATCH v4 10/14] kbuild: check static EXPORT_SYMBOL* by script instead of modpost

From: Nick Desaulniers <ndesaulniers@google.com>
To: Masahiro Yamada <masahiroy@kernel.org>
Cc: linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
	Nathan Chancellor <nathan@kernel.org>,
	Nicolas Schier <nicolas@fjasle.eu>,
	Peter Zijlstra <peterz@infradead.org>,
	linux-modules@vger.kernel.org, linux-s390@vger.kernel.org,
	linuxppc-dev@lists.ozlabs.org,
	clang-built-linux@googlegroups.com,
	Ard Biesheuvel <ardb@kernel.org>,
	Sami Tolvanen <samitolvanen@google.com>
Subject: Re: [PATCH v4 10/14] kbuild: check static EXPORT_SYMBOL* by script instead of modpost
Date: Mon, 9 May 2022 11:05:38 -0700	[thread overview]
Message-ID: <CAKwvOdkhcJB8Bnrt51siRefWe+ZSvHagCs2G011PzkkrD3cxQw@mail.gmail.com> (raw)
In-Reply-To: <20220508190631.2386038-11-masahiroy@kernel.org>

On Sun, May 8, 2022 at 12:10 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> diff --git a/scripts/check-local-export b/scripts/check-local-export
> new file mode 100755
> index 000000000000..d1721fa63057
> --- /dev/null
> +++ b/scripts/check-local-export
> @@ -0,0 +1,48 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-2.0-only
> +#
> +# Copyright (C) 2022 Masahiro Yamada
> +
> +set -e
> +set -o pipefail
> +
> +declare -A symbol_types
> +declare -a export_symbols
> +
> +exit_code=0
> +
> +while read value type name
> +do
> +       # to avoid error for clang LTO; $name may be empty
> +       if [[ $value = -* && -z $name ]]; then
> +               continue
> +       fi
> +
> +       # The first field (value) may be empty. If so, fix it up.
> +       if [[ -z $name ]]; then
> +          name=${type}
> +          type=${value}
> +       fi

Consider adding examples of output from NM as comments where you're
handling special cases.

Aren't BOTH from LTO?  The first case is:

---------------- T strncpy

while the second is

                 U strncpy

IIUC?

Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
-- 
Thanks,
~Nick Desaulniers