From nobody Wed Apr 8 06:40:14 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E2174C433FE for ; Sat, 22 Oct 2022 11:49:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230168AbiJVLtd (ORCPT ); Sat, 22 Oct 2022 07:49:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43524 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229945AbiJVLs4 (ORCPT ); Sat, 22 Oct 2022 07:48:56 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D9C9E251D4F for ; Sat, 22 Oct 2022 04:48:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=21hb22ZOLPug1Y7rU1MItuB/yDHg1vIxzPuc1LZH5hI=; b=PdKGQbC12QBugaGBHXI+1OdOwW jIeT7sZU8f/cCzbk9SkQJaFP1b540Ku1IBJuuSIHSLzg9x2w8Wmc8o276uAHPOpXzXLG3d6TZq0tF ufch0SOHGlt6rJ9GjVJv7If3PI2CCLHZEcs/plOsipgGDnY0U9T2MARB4MNF2md4sW8rQWFDyYM2z ftKN36vAn858VDWdBe2+QF71E9pc0xQfcgKilAvXMfbC3SKqEsFNp+XKGyHGw+FG2kU27DviLQ2k2 Zgve+Gbb5vgj55/AffmFiNzVSPKfRJE8lA9PCBRfZ7JGWZYdwkJx6h4LWZv/Y1jswpVYaPfpTSW4b 7CjP2Teg==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1omCzM-005XdH-1s; Sat, 22 Oct 2022 11:48:28 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id BDB8D302D91; Sat, 22 Oct 2022 13:48:26 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 3B49F28B8E516; Sat, 22 Oct 2022 13:48:26 +0200 (CEST) Message-ID: <20221022114425.038102604@infradead.org> User-Agent: quilt/0.66 Date: Sat, 22 Oct 2022 13:14:12 +0200 From: Peter Zijlstra To: x86@kernel.org, willy@infradead.org, torvalds@linux-foundation.org, akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, linux-mm@kvack.org, aarcange@redhat.com, kirill.shutemov@linux.intel.com, jroedel@suse.de, ubizjak@gmail.com Subject: [PATCH 09/13] x86/mm/pae: Use WRITE_ONCE() References: <20221022111403.531902164@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Disallow write-tearing, that would be really unfortunate. Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/include/asm/pgtable-3level.h | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) --- a/arch/x86/include/asm/pgtable-3level.h +++ b/arch/x86/include/asm/pgtable-3level.h @@ -27,9 +27,9 @@ */ static inline void native_set_pte(pte_t *ptep, pte_t pte) { - ptep->pte_high =3D pte.pte_high; + WRITE_ONCE(ptep->pte_high, pte.pte_high); smp_wmb(); - ptep->pte_low =3D pte.pte_low; + WRITE_ONCE(ptep->pte_low, pte.pte_low); } =20 static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte) @@ -58,16 +58,16 @@ static inline void native_set_pud(pud_t static inline void native_pte_clear(struct mm_struct *mm, unsigned long ad= dr, pte_t *ptep) { - ptep->pte_low =3D 0; + WRITE_ONCE(ptep->pte_low, 0); smp_wmb(); - ptep->pte_high =3D 0; + WRITE_ONCE(ptep->pte_high, 0); } =20 static inline void native_pmd_clear(pmd_t *pmdp) { - pmdp->pmd_low =3D 0; + WRITE_ONCE(pmdp->pmd_low, 0); smp_wmb(); - pmdp->pmd_high =3D 0; + WRITE_ONCE(pmdp->pmd_high, 0); } =20 static inline void native_pud_clear(pud_t *pudp)