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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 863F7EC1122 for ; Mon, 23 Feb 2026 19:11:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Cc:To:In-Reply-To:References :Message-Id:Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date: From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=JQMEKXUSkaG7neBfJPWJGw4i7WIIDOqWY1P7BMsbh/o=; b=BhERs85LpUUY90mWiuH+K4b8uB qpk1fA1NKXXfZjmcAm1hdxIrsXHsCDBzctUIS92Ag9ub05CUWsZSAWGCuMdRv1L85+WmAW39j0QyH kZW13aoVwdbjI9/JHofTkPBxchLJjXdg95C38kIpbRkNepR+wEKK46C+5qP60eI5YV+WHhvSUzBr9 k2D6Bez2K+6ZBw4JzkaCiqJbjHob37BNNHH+VUbIz/MdY/9GYsCiczflv9MNeeGj7i456wA2shKdn t9v1Oxy0R4lV3pMpRMVy+vQ0JBcv2xVbgksw/j4pKKh6kkRq9yl2I/CpLTZw7wIMp8OWVpl6X7q3a vXAAL4VA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vubKu-00000000uV3-36DT; Mon, 23 Feb 2026 19:11:16 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vubKr-00000000uUB-3W9y for linux-arm-kernel@lists.infradead.org; Mon, 23 Feb 2026 19:11:16 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 2FFC24052E; Mon, 23 Feb 2026 19:11:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9AEF7C2BCB5; Mon, 23 Feb 2026 19:11:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771873873; bh=HnBXmWSMpA4wuIlOSxrj2rJBVS6hgScD9wUDZt2+qlw=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=Ec7rpLCAzCv/KZRrk93iS8TKBy0dmX0TGeVU6K4v5xX/A3r84WlF1+spB2Ck3L8+F Ly7Wrk5nDJOONGQAATDn57wpDwS2nId7NK4Vw6pPbxqhuUY3hzAD8tHDKWPeYQ16aq CDGEXsS4binEbD98XFg/kkeskjcNzRQjVBeAbf9hU+krUTPdo4EdS3QsbFUpmWqK+x 83fmxFV+JzQ6K58ijzWKw7NoMdRiJVu6YnkQ+ER5K9bPSOKZ9CiQSYDQwcw9L4xCAq zh+5+/I2WpfYgv6lc5TMsUwpiBXIECDLTQU1MmY+kExyurkj5huthCznFvUTJv9pGV pHQjm+oF6bRiA== From: Nathan Chancellor Date: Mon, 23 Feb 2026 12:10:29 -0700 Subject: [PATCH 2/2] kbuild: Use '-fms-anonymous-structs' if it is available MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260223-fms-anonymous-structs-v1-2-8ee406d3c36c@kernel.org> References: <20260223-fms-anonymous-structs-v1-0-8ee406d3c36c@kernel.org> In-Reply-To: <20260223-fms-anonymous-structs-v1-0-8ee406d3c36c@kernel.org> To: Nathan Chancellor , Nicolas Schier Cc: Linus Torvalds , Catalin Marinas , Will Deacon , Huacai Chen , WANG Xuerui , "James E.J. Bottomley" , Helge Deller , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Ard Biesheuvel , Ilias Apalodimas , Nick Desaulniers , Bill Wendling , Justin Stitt , Kees Cook , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-efi@vger.kernel.org, llvm@lists.linux.dev X-Mailer: b4 0.15-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=2260; i=nathan@kernel.org; h=from:subject:message-id; bh=HnBXmWSMpA4wuIlOSxrj2rJBVS6hgScD9wUDZt2+qlw=; b=owGbwMvMwCUmm602sfCA1DTG02pJDJlzllnaL/tzZJ9j+UqRFKP/HVNX104yzPm+PPiz5Fdep pLXR1Z0d5SyMIhxMciKKbJUP1Y9bmg45yzjjVOTYOawMoEMYeDiFICJlJ1h+Gf2bHvS3EU6Cuzv 6lVV6lZmRpcf6jghx2ystVX28+qCK1GMDBd67Cest0lolmS6u+nMHYW1j73/xRXE1p4vP+5/d3u xCTcA X-Developer-Key: i=nathan@kernel.org; a=openpgp; fpr=2437CB76E544CB6AB3D9DFD399739260CB6CB716 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260223_111113_930319_4C990AD4 X-CRM114-Status: GOOD ( 13.52 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Clang recently added '-fms-anonymous-structs' [1] to specifically enable the Microsoft tagged anonymous structure / union extension, for which the kernel added '-fms-extensions' in commit c4781dc3d1cf ("Kbuild: enable -fms-extensions"). Switch to this more narrow option if it is available, which would have helped avoid the issue addressed by commit a6773e6932cb ("jfs: Rename _inline to avoid conflict with clang's '-fms-extensions'"). GCC has talked about adding a similar flag [2] as well but potentially naming it differently. Move the selection of the flag to Kconfig to make it easier to use cc-option (as CC_FLAGS_DIALECT may be used in arch Makefiles, which may be too early for cc-option in Kbuild) and customize based on compiler flag names. Link: https://github.com/llvm/llvm-project/commit/c391efe6fb67329d8e2fd231692cc6b0ea902956 [1] Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123623 [2] Signed-off-by: Nathan Chancellor --- Makefile | 2 +- init/Kconfig | 5 +++++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 06ff3032a6bc..1d5c0ab9ed5c 100644 --- a/Makefile +++ b/Makefile @@ -791,7 +791,7 @@ endif CC_FLAGS_DIALECT := -std=gnu11 # Allow including a tagged struct or union anonymously in another struct/union. -CC_FLAGS_DIALECT += -fms-extensions +CC_FLAGS_DIALECT += $(CONFIG_CC_MS_EXTENSIONS) # Clang enables warnings about GNU and Microsoft extensions by default, disable # them because this is expected with the above options. ifdef CONFIG_CC_IS_CLANG diff --git a/init/Kconfig b/init/Kconfig index c25869cf59c1..c4282d049463 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -960,6 +960,11 @@ config CC_IMPLICIT_FALLTHROUGH default "-Wimplicit-fallthrough=5" if CC_IS_GCC && $(cc-option,-Wimplicit-fallthrough=5) default "-Wimplicit-fallthrough" if CC_IS_CLANG && $(cc-option,-Wunreachable-code-fallthrough) +config CC_MS_EXTENSIONS + string + default "-fms-anonymous-structs" if $(cc-option,-fms-anonymous-structs) + default "-fms-extensions" + # Currently, disable gcc-10+ array-bounds globally. # It's still broken in gcc-13, so no upper bound yet. config GCC10_NO_ARRAY_BOUNDS -- 2.53.0