From patchwork Mon May 6 16:30:53 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 10931525 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 45E4914DB for ; Mon, 6 May 2019 16:33:08 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 34C2A286AA for ; Mon, 6 May 2019 16:33:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 27DD728847; Mon, 6 May 2019 16:33:08 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C46EE286AA for ; Mon, 6 May 2019 16:33:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727081AbfEFQba (ORCPT ); Mon, 6 May 2019 12:31:30 -0400 Received: from mail-qt1-f201.google.com ([209.85.160.201]:52443 "EHLO mail-qt1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727053AbfEFQb3 (ORCPT ); Mon, 6 May 2019 12:31:29 -0400 Received: by mail-qt1-f201.google.com with SMTP id f14so8470955qtq.19 for ; Mon, 06 May 2019 09:31:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=TZHV8An4OEXfkqFgrZuDjdlNeU7w3PdkPz1ZU4+cbAs=; b=lVlAxmmY4nFExOi7qcKMHLUyvk1dgMtcIDWsIxNnuOIKi7SENIWoorvqYx22FhFeiH qNv3aCOvVP2Cd8JsXC4f5fwupU4T2PFYzqayLiNCFI9HFlqX4lWPhufSiUZxYZlKJbSP xpayFPpaQpM+egkX1gh0HyRA3qPTTcL2EH50qtn8LLi1pPJilWqtH0/kYJiIyAq+8b8K r7XbnjhrPxJ/+aU0+7xAQJYRuQVqDAYCQIetrAi8pdeAX3hMSEX83RJtSz7KeAzNa4AL TEi4LWr1V919AH8PPG3nTQ8k7FsrBwYY7/UQoSLOaq/gIbNGSmHdWR4W58sdfzeJRSfR CtWg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=TZHV8An4OEXfkqFgrZuDjdlNeU7w3PdkPz1ZU4+cbAs=; b=PAkcDFZxmMRWK7guc2Y5WLnXO8wS3xTrnzUABhRHgbz/WNhQNezb6h8Lu+vb3OJR6e C7AouPapG5tRUIe8c34FHtUTAQnAdsYn48yh0GxZxgs372ERS6fk/GBlzIL1a5N1Msir nbVIs90aU4e3tKTcbOQaIxy4eYRqFsWYNly6yX6u1JYj5uRB4oeagy8L7lU4ohZXJWoA bGblqIDdXlTpBk38YgopVkKDoD7C0/vjWc6EqGDNjXENZ3AoJnKmJTe1xItF3Q1nMXlE eRqWbYBa1LRfAKQMu37U/64oWLiorb0KdVYg0A/WBCUTpMp/R3OAjNdHYitsY8lOJuoo 4NIw== X-Gm-Message-State: APjAAAWdBgNs54eYRUMY8hab9m5nQPx4qtNyfQv/lZdbDhl3Ks2Vtqd7 HwbyM+/E6y5cj2oud+4gnDj8ZWQv13/IM9ha X-Google-Smtp-Source: APXvYqzHIfoRqtGD9gbf6U+p/ZZcVtiOU3rLeCD3rrtZumSW95xfAvgD6n9pasKaBp9DQWdRwfRV+d2riHaf6boR X-Received: by 2002:a0c:d449:: with SMTP id r9mr16625749qvh.223.1557160288557; Mon, 06 May 2019 09:31:28 -0700 (PDT) Date: Mon, 6 May 2019 18:30:53 +0200 In-Reply-To: Message-Id: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.21.0.1020.gf2820cf01a-goog Subject: [PATCH v15 07/17] mm, arm64: untag user pointers in mm/gup.c From: Andrey Konovalov To: linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: Catalin Marinas , Vincenzo Frascino , Will Deacon , Mark Rutland , Andrew Morton , Greg Kroah-Hartman , Kees Cook , Yishai Hadas , Felix Kuehling , Alexander Deucher , Christian Koenig , Mauro Carvalho Chehab , Jens Wiklander , Alex Williamson , Leon Romanovsky , Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Robin Murphy , Luc Van Oostenryck , Dave Martin , Kevin Brodsky , Szabolcs Nagy , Andrey Konovalov Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch is a part of a series that extends arm64 kernel ABI to allow to pass tagged user pointers (with the top byte set to something else other than 0x00) as syscall arguments. mm/gup.c provides a kernel interface that accepts user addresses and manipulates user pages directly (for example get_user_pages, that is used by the futex syscall). Since a user can provided tagged addresses, we need to handle this case. Add untagging to gup.c functions that use user addresses for vma lookups. Signed-off-by: Andrey Konovalov Reviewed-by: Catalin Marinas --- mm/gup.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/gup.c b/mm/gup.c index 91819b8ad9cc..2f477a0a7180 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -696,6 +696,8 @@ static long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, if (!nr_pages) return 0; + start = untagged_addr(start); + VM_BUG_ON(!!pages != !!(gup_flags & FOLL_GET)); /* @@ -858,6 +860,8 @@ int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm, struct vm_area_struct *vma; vm_fault_t ret, major = 0; + address = untagged_addr(address); + if (unlocked) fault_flags |= FAULT_FLAG_ALLOW_RETRY;