From patchwork Sat Nov 28 08:46:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 334408 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=-17.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 BFFFEC64E7C for ; Sat, 28 Nov 2020 18:01:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 84F71246E4 for ; Sat, 28 Nov 2020 18:01:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nifty.com header.i=@nifty.com header.b="SElIFciY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730469AbgK1SA0 (ORCPT ); Sat, 28 Nov 2020 13:00:26 -0500 Received: from condef-03.nifty.com ([202.248.20.68]:63837 "EHLO condef-03.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729846AbgK1R6R (ORCPT ); Sat, 28 Nov 2020 12:58:17 -0500 Received: from conuserg-08.nifty.com ([10.126.8.71])by condef-03.nifty.com with ESMTP id 0AS8lwls020580; Sat, 28 Nov 2020 17:48:24 +0900 Received: from localhost.localdomain (softbank126090211135.bbtec.net [126.90.211.135]) (authenticated) by conuserg-08.nifty.com with ESMTP id 0AS8klCf024281; Sat, 28 Nov 2020 17:46:47 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-08.nifty.com 0AS8klCf024281 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1606553208; bh=3ZxQhTM55h3T1rci5XqtW4G9136NvehcsYvGcG3kcgc=; h=From:To:Cc:Subject:Date:From; b=SElIFciYjQNJuulProNcUJ6g9mjA6O9qq6ZNcU+lGQxM4xJ2H6GbcjQChrwQVdtMy 43+MEC/tZn52+NUzUIE+ZDL1Cw8daDnSbuD+PgRrWJADV7BHkydbLYUfzOWruBqV56 Vhf4Hes+x+8MiHQxt2sU5gyJMHCYXBwmEulcrBlxZaqCA61wi+yO7X9URuIez0xvwu kdGZNqcJ8SGzfFt0E0i9BVkt1t+vMk/FuamGdUGmFlHBuC6fnWAGf7gS1t2qNTF0PH pvten505D/ZiSdoqoEPIG4NNVRLMudKUr6O1qbSoZ4zLx2t8m2rp2X3Ktut9GMNRh3 7sqLNV4Grz0eA== X-Nifty-SrcIP: [126.90.211.135] From: Masahiro Yamada To: Miguel Ojeda Cc: Masahiro Yamada , "Jason A. Donenfeld" , Nathan Chancellor , Nick Desaulniers , Shuah Khan , clang-built-linux@googlegroups.com, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, netdev@vger.kernel.org, wireguard@lists.zx2c4.com Subject: [PATCH v2] Compiler Attributes: remove CONFIG_ENABLE_MUST_CHECK Date: Sat, 28 Nov 2020 17:46:39 +0900 Message-Id: <20201128084639.149153-1-masahiroy@kernel.org> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Revert commit cebc04ba9aeb ("add CONFIG_ENABLE_MUST_CHECK"). A lot of warn_unused_result wearings existed in 2006, but until now they have been fixed thanks to people doing allmodconfig tests. Our goal is to always enable __must_check where appropriate, so this CONFIG option is no longer needed. I see a lot of defconfig (arch/*/configs/*_defconfig) files having: # CONFIG_ENABLE_MUST_CHECK is not set I did not touch them for now since it would be a big churn. If arch maintainers want to clean them up, please go ahead. While I was here, I also moved __must_check to compiler_attributes.h from compiler_types.h Signed-off-by: Masahiro Yamada Acked-by: Jason A. Donenfeld --- Changes in v2: - Move __must_check to compiler_attributes.h include/linux/compiler_attributes.h | 7 +++++++ include/linux/compiler_types.h | 6 ------ lib/Kconfig.debug | 8 -------- tools/testing/selftests/wireguard/qemu/debug.config | 1 - 4 files changed, 7 insertions(+), 15 deletions(-) diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h index b2a3f4f641a7..5f3b7edad1a7 100644 --- a/include/linux/compiler_attributes.h +++ b/include/linux/compiler_attributes.h @@ -171,6 +171,13 @@ */ #define __mode(x) __attribute__((__mode__(x))) +/* + * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-warn_005funused_005fresult-function-attribute + * clang: https://clang.llvm.org/docs/AttributeReference.html#nodiscard-warn-unused-result + * + */ +#define __must_check __attribute__((__warn_unused_result__)) + /* * Optional: only supported since gcc >= 7 * diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index ac3fa37a84f9..7ef20d1a6c28 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -110,12 +110,6 @@ struct ftrace_likely_data { unsigned long constant; }; -#ifdef CONFIG_ENABLE_MUST_CHECK -#define __must_check __attribute__((__warn_unused_result__)) -#else -#define __must_check -#endif - #if defined(CC_USING_HOTPATCH) #define notrace __attribute__((hotpatch(0, 0))) #elif defined(CC_USING_PATCHABLE_FUNCTION_ENTRY) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c789b39ed527..cb8ef4fd0d02 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -286,14 +286,6 @@ config GDB_SCRIPTS endif # DEBUG_INFO -config ENABLE_MUST_CHECK - bool "Enable __must_check logic" - default y - help - Enable the __must_check logic in the kernel build. Disable this to - suppress the "warning: ignoring return value of 'foo', declared with - attribute warn_unused_result" messages. - config FRAME_WARN int "Warn for stack frames larger than" range 0 8192 diff --git a/tools/testing/selftests/wireguard/qemu/debug.config b/tools/testing/selftests/wireguard/qemu/debug.config index b50c2085c1ac..fe07d97df9fa 100644 --- a/tools/testing/selftests/wireguard/qemu/debug.config +++ b/tools/testing/selftests/wireguard/qemu/debug.config @@ -1,5 +1,4 @@ CONFIG_LOCALVERSION="-debug" -CONFIG_ENABLE_MUST_CHECK=y CONFIG_FRAME_POINTER=y CONFIG_STACK_VALIDATION=y CONFIG_DEBUG_KERNEL=y