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=-11.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 C6A4AC54E8D for ; Tue, 12 May 2020 14:38:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A4724206F5 for ; Tue, 12 May 2020 14:38:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730328AbgELOhC (ORCPT ); Tue, 12 May 2020 10:37:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39366 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727109AbgELOhA (ORCPT ); Tue, 12 May 2020 10:37:00 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4AE3CC061A0C; Tue, 12 May 2020 07:37:00 -0700 (PDT) Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jYW1f-0005nH-V4; Tue, 12 May 2020 16:36:56 +0200 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id 8D3551C0475; Tue, 12 May 2020 16:36:55 +0200 (CEST) Date: Tue, 12 May 2020 14:36:55 -0000 From: "tip-bot2 for Will Deacon" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: locking/kcsan] locking/barriers: Use '__unqual_scalar_typeof' for load-acquire macros Cc: Will Deacon , Thomas Gleixner , "Peter Zijlstra (Intel)" , Linus Torvalds , Arnd Bergmann , x86 , LKML In-Reply-To: <20200511204150.27858-14-will@kernel.org> References: <20200511204150.27858-14-will@kernel.org> MIME-Version: 1.0 Message-ID: <158929421549.390.12460097997822377133.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the locking/kcsan branch of tip: Commit-ID: 0229d80867ef27b3e41585a784d5f78695a58f95 Gitweb: https://git.kernel.org/tip/0229d80867ef27b3e41585a784d5f78695a58f95 Author: Will Deacon AuthorDate: Mon, 11 May 2020 21:41:45 +01:00 Committer: Thomas Gleixner CommitterDate: Tue, 12 May 2020 11:04:15 +02:00 locking/barriers: Use '__unqual_scalar_typeof' for load-acquire macros Passing volatile-qualified pointers to the asm-generic implementations of the load-acquire macros results in a re-load from the stack due to the temporary result variable inheriting the volatile semantics thanks to the use of 'typeof()'. Define these temporary variables using 'unqual_scalar_typeof' to drop the volatile qualifier in the case that they are scalar types. Signed-off-by: Will Deacon Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Arnd Bergmann Link: https://lkml.kernel.org/r/20200511204150.27858-14-will@kernel.org --- include/asm-generic/barrier.h | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h index 85b28eb..2eacaf7 100644 --- a/include/asm-generic/barrier.h +++ b/include/asm-generic/barrier.h @@ -128,10 +128,10 @@ do { \ #ifndef __smp_load_acquire #define __smp_load_acquire(p) \ ({ \ - typeof(*p) ___p1 = READ_ONCE(*p); \ + __unqual_scalar_typeof(*p) ___p1 = READ_ONCE(*p); \ compiletime_assert_atomic_type(*p); \ __smp_mb(); \ - ___p1; \ + (typeof(*p))___p1; \ }) #endif @@ -183,10 +183,10 @@ do { \ #ifndef smp_load_acquire #define smp_load_acquire(p) \ ({ \ - typeof(*p) ___p1 = READ_ONCE(*p); \ + __unqual_scalar_typeof(*p) ___p1 = READ_ONCE(*p); \ compiletime_assert_atomic_type(*p); \ barrier(); \ - ___p1; \ + (typeof(*p))___p1; \ }) #endif @@ -229,14 +229,14 @@ do { \ #ifndef smp_cond_load_relaxed #define smp_cond_load_relaxed(ptr, cond_expr) ({ \ typeof(ptr) __PTR = (ptr); \ - typeof(*ptr) VAL; \ + __unqual_scalar_typeof(*ptr) VAL; \ for (;;) { \ VAL = READ_ONCE(*__PTR); \ if (cond_expr) \ break; \ cpu_relax(); \ } \ - VAL; \ + (typeof(*ptr))VAL; \ }) #endif @@ -250,10 +250,10 @@ do { \ */ #ifndef smp_cond_load_acquire #define smp_cond_load_acquire(ptr, cond_expr) ({ \ - typeof(*ptr) _val; \ + __unqual_scalar_typeof(*ptr) _val; \ _val = smp_cond_load_relaxed(ptr, cond_expr); \ smp_acquire__after_ctrl_dep(); \ - _val; \ + (typeof(*ptr))_val; \ }) #endif