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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 AD218C282CA for ; Wed, 13 Feb 2019 02:34:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7ADE6222CE for ; Wed, 13 Feb 2019 02:34:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550025286; bh=czenjSTG1ljAv4LkUvnKRQP/4xeHqoDp06x9vE3F3hg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Xm3RFhhmKw9U7tSjxVGIMnafYdI6/3kUIYbHJ27YXejYCxunlFoSHV76qnPUeja6h ekJfi+6pH2zQF86uMvsFWhRc5nTngJFr37DNvyYmqTHyujm2/DUTLRCcxcP2oUelwS nB9YRyrsEPI2GdNgWscQRuxPf1u0cB7+XZZEQmS8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387797AbfBMCeo (ORCPT ); Tue, 12 Feb 2019 21:34:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:38210 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730485AbfBMCek (ORCPT ); Tue, 12 Feb 2019 21:34:40 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E5D19206B6; Wed, 13 Feb 2019 02:34:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550025279; bh=czenjSTG1ljAv4LkUvnKRQP/4xeHqoDp06x9vE3F3hg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pGhTuLoBSn4opZMiLninxw5DndfMMOqYncjKCa75d3aeLreg7D8SnZsPKEk0K/Ouj k4X6PdJ5fjaSRHCWN3nC5MKII+yk3fdWGgOflRIwfPXxKsvFw+m+10spxQ2+f7LHqe KLeQbksumaKP0YWsXpJBeksWJdCeFPqr+jTRmWqE= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Michael S. Tsirkin" , Eli Friedman , Joe Perches , Linus Torvalds , Miguel Ojeda , Sasha Levin , linux-sparse@vger.kernel.org Subject: [PATCH AUTOSEL 4.20 041/105] include/linux/compiler*.h: fix OPTIMIZER_HIDE_VAR Date: Tue, 12 Feb 2019 21:32:32 -0500 Message-Id: <20190213023336.19019-41-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190213023336.19019-1-sashal@kernel.org> References: <20190213023336.19019-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Michael S. Tsirkin" [ Upstream commit 3e2ffd655cc6a694608d997738989ff5572a8266 ] Since commit 815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h mutually exclusive") clang no longer reuses the OPTIMIZER_HIDE_VAR macro from compiler-gcc - instead it gets the version in include/linux/compiler.h. Unfortunately that version doesn't actually prevent compiler from optimizing out the variable. Fix up by moving the macro out from compiler-gcc.h to compiler.h. Compilers without incline asm support will keep working since it's protected by an ifdef. Also fix up comments to match reality since we are no longer overriding any macros. Build-tested with gcc and clang. Fixes: 815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h mutually exclusive") Cc: Eli Friedman Cc: Joe Perches Cc: Linus Torvalds Reviewed-by: Nick Desaulniers Signed-off-by: Michael S. Tsirkin Signed-off-by: Miguel Ojeda Signed-off-by: Sasha Levin --- include/linux/compiler-clang.h | 5 ++--- include/linux/compiler-gcc.h | 4 ---- include/linux/compiler-intel.h | 4 +--- include/linux/compiler.h | 4 +++- 4 files changed, 6 insertions(+), 11 deletions(-) diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h index 3e7dafb3ea80..7ddaeb5182e3 100644 --- a/include/linux/compiler-clang.h +++ b/include/linux/compiler-clang.h @@ -3,9 +3,8 @@ #error "Please don't include directly, include instead." #endif -/* Some compiler specific definitions are overwritten here - * for Clang compiler - */ +/* Compiler specific definitions for Clang compiler */ + #define uninitialized_var(x) x = *(&(x)) /* same as gcc, this was present in clang-2.6 so we can assume it works diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index 977ddf2774f9..c61c4bb2bd15 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -58,10 +58,6 @@ (typeof(ptr)) (__ptr + (off)); \ }) -/* Make the optimizer believe the variable can be manipulated arbitrarily. */ -#define OPTIMIZER_HIDE_VAR(var) \ - __asm__ ("" : "=r" (var) : "0" (var)) - /* * A trick to suppress uninitialized variable warning without generating any * code diff --git a/include/linux/compiler-intel.h b/include/linux/compiler-intel.h index 517bd14e1222..b17f3cd18334 100644 --- a/include/linux/compiler-intel.h +++ b/include/linux/compiler-intel.h @@ -5,9 +5,7 @@ #ifdef __ECC -/* Some compiler specific definitions are overwritten here - * for Intel ECC compiler - */ +/* Compiler specific definitions for Intel ECC compiler */ #include diff --git a/include/linux/compiler.h b/include/linux/compiler.h index fc5004a4b07d..445348facea9 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -161,7 +161,9 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, #endif #ifndef OPTIMIZER_HIDE_VAR -#define OPTIMIZER_HIDE_VAR(var) barrier() +/* Make the optimizer believe the variable can be manipulated arbitrarily. */ +#define OPTIMIZER_HIDE_VAR(var) \ + __asm__ ("" : "=r" (var) : "0" (var)) #endif /* Not-quite-unique ID. */ -- 2.19.1