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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,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 1B01EC433F5 for ; Mon, 13 Sep 2021 15:19:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EFC5160FF2 for ; Mon, 13 Sep 2021 15:19:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230205AbhIMPVD (ORCPT ); Mon, 13 Sep 2021 11:21:03 -0400 Received: from pegase2.c-s.fr ([93.17.235.10]:58489 "EHLO pegase2.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242401AbhIMPUp (ORCPT ); Mon, 13 Sep 2021 11:20:45 -0400 Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4H7VWh46wMz9sVt; Mon, 13 Sep 2021 17:19:28 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase2.c-s.fr ([172.26.127.65]) by localhost (pegase2.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Czid7jzSJVH2; Mon, 13 Sep 2021 17:19:28 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase2.c-s.fr (Postfix) with ESMTP id 4H7VWh3KbNz9sV3; Mon, 13 Sep 2021 17:19:28 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 5ABEE8B779; Mon, 13 Sep 2021 17:19:28 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id qYQffU0wI8o9; Mon, 13 Sep 2021 17:19:28 +0200 (CEST) Received: from PO20335.IDSI0.si.c-s.fr (unknown [172.25.230.107]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 2CF478B774; Mon, 13 Sep 2021 17:19:28 +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 18DFJKIo157776 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Mon, 13 Sep 2021 17:19:20 +0200 Received: (from chleroy@localhost) by PO20335.IDSI0.si.c-s.fr (8.16.1/8.16.1/Submit) id 18DFJKIR157775; Mon, 13 Sep 2021 17:19:20 +0200 X-Authentication-Warning: PO20335.IDSI0.si.c-s.fr: chleroy set sender to christophe.leroy@csgroup.eu using -f From: Christophe Leroy To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , ebiederm@xmission.com, hch@infradead.org Cc: Christophe Leroy , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH RESEND v3 5/6] powerpc/uaccess: Add unsafe_clear_user() Date: Mon, 13 Sep 2021 17:19:09 +0200 Message-Id: <9e73ef4ae948d232e344db461829cc7699f43eda.1631537060.git.christophe.leroy@csgroup.eu> X-Mailer: git-send-email 2.31.1 In-Reply-To: <1718f38859d5366f82d5bef531f255cedf537b5d.1631537060.git.christophe.leroy@csgroup.eu> References: <1718f38859d5366f82d5bef531f255cedf537b5d.1631537060.git.christophe.leroy@csgroup.eu> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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) \ -- 2.31.1