From patchwork Mon Jul 19 14:51:35 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "gregkh@linuxfoundation.org" X-Patchwork-Id: 480959 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=-25.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING, 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 4A9F4C07E95 for ; Mon, 19 Jul 2021 15:43:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 375E961222 for ; Mon, 19 Jul 2021 15:43:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344669AbhGSPCc (ORCPT ); Mon, 19 Jul 2021 11:02:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:52608 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344321AbhGSO7e (ORCPT ); Mon, 19 Jul 2021 10:59:34 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 94FE76120C; Mon, 19 Jul 2021 15:39:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626709187; bh=lxo5OpBggpjvMAzCMAYvT0FbGUxzwNEToMFBodGRDhg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BDYDAmXyQzagF4e1rCRHrijAG0mrdior3W8KTJofP4a+ft9SNtiExjRhmPLcfyTjo WOLmkaziHlCQls4dsARKkRq6HCzhog7VVOwQTcTH78SQktFW+3egVXmSF9Iq4Yneup 7l8dYwfJWuZtolTp2mcfh05o6IVVV/g/Ri2hoebk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Michael Ellerman Subject: [PATCH 4.19 284/421] powerpc/barrier: Avoid collision with clangs __lwsync macro Date: Mon, 19 Jul 2021 16:51:35 +0200 Message-Id: <20210719144956.189560616@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144946.310399455@linuxfoundation.org> References: <20210719144946.310399455@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Nathan Chancellor commit 015d98149b326e0f1f02e44413112ca8b4330543 upstream. A change in clang 13 results in the __lwsync macro being defined as __builtin_ppc_lwsync, which emits 'lwsync' or 'msync' depending on what the target supports. This breaks the build because of -Werror in arch/powerpc, along with thousands of warnings: In file included from arch/powerpc/kernel/pmc.c:12: In file included from include/linux/bug.h:5: In file included from arch/powerpc/include/asm/bug.h:109: In file included from include/asm-generic/bug.h:20: In file included from include/linux/kernel.h:12: In file included from include/linux/bitops.h:32: In file included from arch/powerpc/include/asm/bitops.h:62: arch/powerpc/include/asm/barrier.h:49:9: error: '__lwsync' macro redefined [-Werror,-Wmacro-redefined] #define __lwsync() __asm__ __volatile__ (stringify_in_c(LWSYNC) : : :"memory") ^ :308:9: note: previous definition is here #define __lwsync __builtin_ppc_lwsync ^ 1 error generated. Undefine this macro so that the runtime patching introduced by commit 2d1b2027626d ("powerpc: Fixup lwsync at runtime") continues to work properly with clang and the build no longer breaks. Cc: stable@vger.kernel.org Signed-off-by: Nathan Chancellor Reviewed-by: Nick Desaulniers Signed-off-by: Michael Ellerman Link: https://github.com/ClangBuiltLinux/linux/issues/1386 Link: https://github.com/llvm/llvm-project/commit/62b5df7fe2b3fda1772befeda15598fbef96a614 Link: https://lore.kernel.org/r/20210528182752.1852002-1-nathan@kernel.org Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/include/asm/barrier.h | 2 ++ 1 file changed, 2 insertions(+) --- a/arch/powerpc/include/asm/barrier.h +++ b/arch/powerpc/include/asm/barrier.h @@ -44,6 +44,8 @@ # define SMPWMB eieio #endif +/* clang defines this macro for a builtin, which will not work with runtime patching */ +#undef __lwsync #define __lwsync() __asm__ __volatile__ (stringify_in_c(LWSYNC) : : :"memory") #define dma_rmb() __lwsync() #define dma_wmb() __asm__ __volatile__ (stringify_in_c(SMPWMB) : : :"memory")