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 C6ABAC54E8D for ; Tue, 12 May 2020 14:37:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ACD8120643 for ; Tue, 12 May 2020 14:37:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730348AbgELOhE (ORCPT ); Tue, 12 May 2020 10:37:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39368 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730258AbgELOhA (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 72EDEC061A0E; 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-0005mt-IR; Tue, 12 May 2020 16:36:55 +0200 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id 2D7C91C02FC; 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] arm64: barrier: Use '__unqual_scalar_typeof' for acquire/release macros Cc: Will Deacon , Thomas Gleixner , "Peter Zijlstra (Intel)" , Mark Rutland , Linus Torvalds , Arnd Bergmann , x86 , LKML In-Reply-To: <20200511204150.27858-15-will@kernel.org> References: <20200511204150.27858-15-will@kernel.org> MIME-Version: 1.0 Message-ID: <158929421507.390.1894315072790883073.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: a9e777c275422371c86a3bdc8d81f4a21ec2a63c Gitweb: https://git.kernel.org/tip/a9e777c275422371c86a3bdc8d81f4a21ec2a63c Author: Will Deacon AuthorDate: Mon, 11 May 2020 21:41:46 +01:00 Committer: Thomas Gleixner CommitterDate: Tue, 12 May 2020 11:04:16 +02:00 arm64: barrier: Use '__unqual_scalar_typeof' for acquire/release macros Passing volatile-qualified pointers to the arm64 implementations of the load-acquire/store-release macros results in a re-load from the stack and a bunch of associated stack-protector churn 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) Acked-by: Mark Rutland Cc: Linus Torvalds Cc: Arnd Bergmann Link: https://lkml.kernel.org/r/20200511204150.27858-15-will@kernel.org --- arch/arm64/include/asm/barrier.h | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h index 7d9cc5e..fb4c275 100644 --- a/arch/arm64/include/asm/barrier.h +++ b/arch/arm64/include/asm/barrier.h @@ -76,8 +76,8 @@ static inline unsigned long array_index_mask_nospec(unsigned long idx, #define __smp_store_release(p, v) \ do { \ typeof(p) __p = (p); \ - union { typeof(*p) __val; char __c[1]; } __u = \ - { .__val = (__force typeof(*p)) (v) }; \ + union { __unqual_scalar_typeof(*p) __val; char __c[1]; } __u = \ + { .__val = (__force __unqual_scalar_typeof(*p)) (v) }; \ compiletime_assert_atomic_type(*p); \ kasan_check_write(__p, sizeof(*p)); \ switch (sizeof(*p)) { \ @@ -110,7 +110,7 @@ do { \ #define __smp_load_acquire(p) \ ({ \ - union { typeof(*p) __val; char __c[1]; } __u; \ + union { __unqual_scalar_typeof(*p) __val; char __c[1]; } __u; \ typeof(p) __p = (p); \ compiletime_assert_atomic_type(*p); \ kasan_check_read(__p, sizeof(*p)); \ @@ -136,33 +136,33 @@ do { \ : "Q" (*__p) : "memory"); \ break; \ } \ - __u.__val; \ + (typeof(*p))__u.__val; \ }) #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; \ __cmpwait_relaxed(__PTR, VAL); \ } \ - VAL; \ + (typeof(*ptr))VAL; \ }) #define smp_cond_load_acquire(ptr, cond_expr) \ ({ \ typeof(ptr) __PTR = (ptr); \ - typeof(*ptr) VAL; \ + __unqual_scalar_typeof(*ptr) VAL; \ for (;;) { \ VAL = smp_load_acquire(__PTR); \ if (cond_expr) \ break; \ __cmpwait_relaxed(__PTR, VAL); \ } \ - VAL; \ + (typeof(*ptr))VAL; \ }) #include