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Date:   Thu, 16 Jun 2022 19:57:59 +0000
Message-Id: <20220616195759.3214538-1-samitolvanen@google.com>
Mime-Version: 1.0
Subject: [PATCH] kbuild: Ignore __this_module in gen_autoksyms.sh
From:   Sami Tolvanen <samitolvanen@google.com>
To:     Masahiro Yamada <masahiroy@kernel.org>
Cc:     Nicolas Schier <nicolas@fjasle.eu>,
        Alexander Lobakin <alobakin@pm.me>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Steve Muckle <smuckle@google.com>,
        linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
        Sami Tolvanen <samitolvanen@google.com>
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Module object files can contain an undefined reference to __this_module,
which isn't resolved until we link the final .ko. The kernel doesn't
export this symbol, so ignore it in gen_autoksyms.sh. This avoids an
unnecessary vmlinux rebuild with UNUSED_KSYMS_WHITELIST when we have a
symbol list that already contains all the module dependencies.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
---
 scripts/gen_autoksyms.sh | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/scripts/gen_autoksyms.sh b/scripts/gen_autoksyms.sh
index faacf7062122..653fadbad302 100755
--- a/scripts/gen_autoksyms.sh
+++ b/scripts/gen_autoksyms.sh
@@ -56,4 +56,7 @@ EOT
 # point addresses.
 sed -e 's/^\.//' |
 sort -u |
+# Ignore __this_module. It's not an exported symbol, and will be resolved
+# when the final .ko's are linked.
+grep -v '^__this_module$' |
 sed -e 's/\(.*\)/#define __KSYM_\1 1/' >> "$output_file"
-- 
2.36.1.476.g0c4daa206d-goog