From patchwork Sun Sep 16 22:00:00 2001 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 1527312 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=112.213.38.117; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org; receiver=) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4H7Pdh1L9Lz9sX3 for ; Mon, 13 Sep 2021 21:39:20 +1000 (AEST) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4H7Pdg73mRz3cMK for ; Mon, 13 Sep 2021 21:39:19 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=csgroup.eu (client-ip=93.17.236.30; helo=pegase1.c-s.fr; envelope-from=christophe.leroy@csgroup.eu; receiver=) Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4H7Pbj1ZcZz2yQD for ; Mon, 13 Sep 2021 21:37:37 +1000 (AEST) Received: from localhost (mailhub3.si.c-s.fr [192.168.12.233]) by localhost (Postfix) with ESMTP id 4H7PbL289tz9s4R; Mon, 13 Sep 2021 13:37:18 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id wasQkE_IzWSp; Mon, 13 Sep 2021 13:37:18 +0200 (CEST) Received: from PO20335.IDSI0.si.c-s.fr (unknown [172.25.230.107]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (Client did not present a certificate) by pegase1.c-s.fr (Postfix) with ESMTPS id 4H7PbK3VLdz9s42; Mon, 13 Sep 2021 13:37:17 +0200 (CEST) Received: from PO20335.IDSI0.si.c-s.fr (localhost [127.0.0.1]) by PO20335.IDSI0.si.c-s.fr (8.16.1/8.16.1) with ESMTPS id 18DBbHJ3143507 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Mon, 13 Sep 2021 13:37:17 +0200 Received: (from chleroy@localhost) by PO20335.IDSI0.si.c-s.fr (8.16.1/8.16.1/Submit) id 18DBbHve143506; Mon, 13 Sep 2021 13:37:17 +0200 Date: Mon, 17 Sep 2001 00:00:00 +0200 X-Authentication-Warning: PO20335.IDSI0.si.c-s.fr: chleroy set sender to christophe.leroy@c-s.fr using -f Message-Id: <9e73ef4ae948d232e344db461829cc7699f43eda.1631532888.git.christophe.leroy@csgroup.eu> In-Reply-To: <1718f38859d5366f82d5bef531f255cedf537b5d.1631532888.git.christophe.leroy@csgroup.eu> References: <1718f38859d5366f82d5bef531f255cedf537b5d.1631532888.git.christophe.leroy@csgroup.eu> From: Christophe Leroy Subject: [PATCH v3 5/6] powerpc/uaccess: Add unsafe_clear_user() To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , ebiederm@xmission.com, hch@infradead.org X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Implement unsafe_clear_user() for powerpc. It's a copy/paste of unsafe_copy_to_user() with value 0 as source. It may be improved in a later patch by using 'dcbz' instruction to zeroize full cache lines at once. Signed-off-by: Christophe Leroy --- arch/powerpc/include/asm/uaccess.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h index 22c79ab40006..962b675485ff 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -467,6 +467,26 @@ do { \ unsafe_put_user(*(u8*)(_src + _i), (u8 __user *)(_dst + _i), e); \ } while (0) +#define unsafe_clear_user(d, l, e) \ +do { \ + u8 __user *_dst = (u8 __user *)(d); \ + size_t _len = (l); \ + int _i; \ + \ + for (_i = 0; _i < (_len & ~(sizeof(u64) - 1)); _i += sizeof(u64)) \ + unsafe_put_user(0, (u64 __user *)(_dst + _i), e); \ + if (_len & 4) { \ + unsafe_put_user(0, (u32 __user *)(_dst + _i), e); \ + _i += 4; \ + } \ + if (_len & 2) { \ + unsafe_put_user(0, (u16 __user *)(_dst + _i), e); \ + _i += 2; \ + } \ + if (_len & 1) \ + unsafe_put_user(0, (u8 __user *)(_dst + _i), e); \ +} while (0) + #define HAVE_GET_KERNEL_NOFAULT #define __get_kernel_nofault(dst, src, type, err_label) \