From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 97E17C433E0 for ; Sat, 23 Jan 2021 15:15:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 632B822AAD for ; Sat, 23 Jan 2021 15:15:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725274AbhAWPPA (ORCPT ); Sat, 23 Jan 2021 10:15:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60476 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725535AbhAWPO5 (ORCPT ); Sat, 23 Jan 2021 10:14:57 -0500 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 756CDC06174A for ; Sat, 23 Jan 2021 07:14:17 -0800 (PST) Received: by mail-pj1-x1030.google.com with SMTP id j12so5625032pjy.5 for ; Sat, 23 Jan 2021 07:14:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=KTy8n+bNEd4gKJ9+t7A4mZcH7giU4TFs0RUo2PYg5Ec=; b=UxxNr3YpD9YBVQbYAyjJjJWFfl+beyLmtL53wnThX2tbCnVaexxDvLKMv6nX97vmJL dPrh7fERj0dUfCbxnppUwbQfCO6Kdh9kDvwP+OXKmSuJ55WDFAylPN/SHjrDemghyf0P kLgnLv5MfpVi+Mi6wQPkEzB4qjcWl0gxTR1ogA3cty2EWv/AwrijGuKHwQLs5YlAkr2m hcmKF1PNzz416Ws9iouT9MsRuMHeHoe4PqeywmqbhTpfTuk7/ilJcRPl3j2XHxNMZAI3 CT6RmsAKG1oZ6xmPlnhZGPCbRoAiS2gtP3c1hncP5z3bhJzq3vIpQN2/SJZNB5lcECvV 04QQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=KTy8n+bNEd4gKJ9+t7A4mZcH7giU4TFs0RUo2PYg5Ec=; b=VELL1nSYFnIyCkoDqh4pLMms/HhjY98PrTtAHDUOnuoZODV0G86HATilOQm0v6hjYH U1i3hveQKNcvgK3p+sP4UvUPQ4CgozUv039u+l0QYCXrvrH1WqoiyWJxnzZipmNT5zFq I6b0jSNgM2OebmZGHgOQMIT+Vgj41IeUNuyXYHQ/xAeuWOBn4E12YfsT/TeDEjosdd84 kNKDXyk7ubIfpr+ire/zotG/qTjOPjeH7ZifnjgdIUg+PboQiKPq4EKQS6+cYo8Olx4S ymbk3oCLa5nWO8ntFqcFyXuirft54/OAXqFeykvJeHXqaoEkKo7AE7Tcfl1Tvhm5sqY3 EJlg== X-Gm-Message-State: AOAM531/iTeb2qYVYL5J1Alx+tEmLm2AgZ8BczfeHl2KPTJhNlIE3nOq IBsdULlIbvS+aW/Tx63hUILqkyjZMYDk9w== X-Google-Smtp-Source: ABdhPJyawreUvgM30jreQ3mbYFF9icNJijFyxamoBHb0+gQwNeZEpJp5E9zZHs0h9YmWiQeItodIrg== X-Received: by 2002:a17:902:7043:b029:df:cabc:cc97 with SMTP id h3-20020a1709027043b02900dfcabccc97mr1429590plt.4.1611414856478; Sat, 23 Jan 2021 07:14:16 -0800 (PST) Received: from localhost.localdomain ([2405:201:600d:a089:8c2b:8940:3286:eb08]) by smtp.googlemail.com with ESMTPSA id 3sm12107301pfw.204.2021.01.23.07.14.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 23 Jan 2021 07:14:15 -0800 (PST) From: Aditya Srivastava To: linux-kernel@vger.kernel.org Cc: yashsri421@gmail.com, lukas.bulwahn@gmail.com, dwaipayanray1@gmail.com, broonie@kernel.org, joe@perches.com, ndesaulniers@google.com, jpoimboe@redhat.com, linux-kernel-mentees@lists.linuxfoundation.org, clang-built-linux@googlegroups.com Subject: [PATCH v2] checkpatch: add warning for avoiding .L prefix symbols in assembly files Date: Sat, 23 Jan 2021 20:44:05 +0530 Message-Id: <20210123151405.26267-1-yashsri421@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org objtool requires that all code must be contained in an ELF symbol. Symbol names that have a '.L' prefix do not emit symbol table entries, as they have special meaning for the assembler. '.L' prefixed symbols can be used within a code region, but should be avoided for denoting a range of code via 'SYM_*_START/END' annotations. Add a new check to emit a warning on finding the usage of '.L' symbols for '.S' files in arch/x86/entry/* and arch/x86/lib/*, if it denotes range of code via SYM_*_START/END annotation pair. Suggested-by: Mark Brown Link: https://groups.google.com/g/clang-built-linux/c/-drkmLgu-cU/m/4staOlf-CgAJ Signed-off-by: Aditya Srivastava --- * Applies perfectly on next-20210122 Changes in v2: - Reduce the check to only SYM_*_START/END lines - Reduce the check for only .S files in arch/x86/entry/* and arch/x86/lib/* as suggested by Josh and Nick - Modify commit message scripts/checkpatch.pl | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 7030c4d6d126..e36cdf96dfe3 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -3590,6 +3590,13 @@ sub process { } } +# check for .L prefix local symbols in .S files + if ($realfile =~ m@^arch/x86/(?:entry|lib)/.*\.S$@ && + $line =~ /^\+\s*SYM_[A-Z]+_(?:START|END)(?:_[A-Z_]+)?\s*\(\s*\.L/) { + WARN("AVOID_L_PREFIX", + "Avoid using '.L' prefixed local symbol names for denoting a range of code via 'SYM_*_START/END' annotations; see Documentation/asm-annotations.rst\n" . $herecurr); + } + # check we are in a valid source file C or perl if not then ignore this hunk next if ($realfile !~ /\.(h|c|pl|dtsi|dts)$/); -- 2.17.1