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=-11.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 66A11C433E7 for ; Tue, 13 Oct 2020 23:48:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2D3D621D7F for ; Tue, 13 Oct 2020 23:48:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602632884; bh=1IE0rXmrIv5WEpxIUQFbF+jl/alNJTZrKr0kJ0mM3ao=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=l5afaX830D7kZu4qWu4ydQw0ZmLKJA8aeLAgTJbkhnUCF/FpPBDBbQK5btEj+/WAl RTKjo1luVKcdeDKiHEr1dWcwu5cS1VJvtaIi3W0Ak6qokRzMhnO7zw9XRgu5JwD7hG Z7zGn/KaJTskyvIMaW28uvi774sCFKpbSNRJrjCo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389127AbgJMXsD (ORCPT ); Tue, 13 Oct 2020 19:48:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:59258 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389017AbgJMXsD (ORCPT ); Tue, 13 Oct 2020 19:48:03 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5DC3C21D7A; Tue, 13 Oct 2020 23:48:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602632882; bh=1IE0rXmrIv5WEpxIUQFbF+jl/alNJTZrKr0kJ0mM3ao=; h=Date:From:To:Subject:In-Reply-To:From; b=JFA016Z7tWF4TmfyvM8J/O17jgETStu9tYsT9jjGrXOLlS2dTcRoFV0SfAmJCON88 KDBAQnw7FXtZsminykfsM2OgPZuSdnvfRoE00o+EJAPChDJBIET6YHvJFiIvbJkvOP f92uN25V4oNdQ1TpiuOmowUyVHR1Olnxiv7JCawk= Date: Tue, 13 Oct 2020 16:48:01 -0700 From: Andrew Morton To: akpm@linux-foundation.org, gregkh@linuxfoundation.org, jeyu@kernel.org, keescook@chromium.org, linux-mm@kvack.org, lkp@intel.com, maennich@google.com, mm-commits@vger.kernel.org, natechancellor@gmail.com, ndesaulniers@google.com, torvalds@linux-foundation.org, will@kernel.org, yamada.masahiro@socionext.com Subject: [patch 009/181] export.h: fix section name for CONFIG_TRIM_UNUSED_KSYMS for Clang Message-ID: <20201013234801.zMU594pMt%akpm@linux-foundation.org> In-Reply-To: <20201013164658.3bfd96cc224d8923e66a9f4e@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Nick Desaulniers Subject: export.h: fix section name for CONFIG_TRIM_UNUSED_KSYMS for Clang When enabling CONFIG_TRIM_UNUSED_KSYMS, the linker will warn about the orphan sections: (".discard.ksym") is being placed in '".discard.ksym"' repeatedly when linking vmlinux. This is because the stringification operator, `#`, in the preprocessor escapes strings. GCC and Clang differ in how they treat section names that contain \". The portable solution is to not use a string literal with the preprocessor stringification operator. Link: https://bugs.llvm.org/show_bug.cgi?id=42950 Link: https://github.com/ClangBuiltLinux/linux/issues/1166 Link: https://lkml.kernel.org/r/20200929190701.398762-1-ndesaulniers@google.com Fixes: commit bbda5ec671d3 ("kbuild: simplify dependency generation for CONFIG_TRIM_UNUSED_KSYMS") Signed-off-by: Nick Desaulniers Reported-by: kbuild test robot Suggested-by: Kees Cook Reviewed-by: Kees Cook Cc: Nathan Chancellor Cc: Masahiro Yamada Cc: Matthias Maennich Cc: Jessica Yu Cc: Greg Kroah-Hartman Cc: Will Deacon Signed-off-by: Andrew Morton --- include/linux/export.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/include/linux/export.h~exporth-fix-section-name-for-config_trim_unused_ksyms-for-clang +++ a/include/linux/export.h @@ -130,7 +130,7 @@ struct kernel_symbol { * discarded in the final link stage. */ #define __ksym_marker(sym) \ - static int __ksym_marker_##sym[0] __section(".discard.ksym") __used + static int __ksym_marker_##sym[0] __section(.discard.ksym) __used #define __EXPORT_SYMBOL(sym, sec, ns) \ __ksym_marker(sym); \ _