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=-16.5 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,T_DKIMWL_WL_MED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 619B2C04A6B for ; Mon, 6 May 2019 16:33:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 32DEA205C9 for ; Mon, 6 May 2019 16:33:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="lVlAxmmY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727063AbfEFQdL (ORCPT ); Mon, 6 May 2019 12:33:11 -0400 Received: from mail-qt1-f201.google.com ([209.85.160.201]:56992 "EHLO mail-qt1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727051AbfEFQb3 (ORCPT ); Mon, 6 May 2019 12:31:29 -0400 Received: by mail-qt1-f201.google.com with SMTP id e7so8722816qtq.23 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=Z+vMyt0nSoJwJOluUW3rfIA8Ek5zMkiuz2lAe9w+QmPoY22/UXqdjIs68ZPjNs34P8 c/VUQus9XIJXWABns+QotnqsBYIZluzEq0Q0RWZMsitHc2UIC2C2ygxdKYsOIjVNIXiI u+8hpBqQsR0VtBifF8UZ4x8dcnILcxQg5dbegh/tHwDvUq2eWQm7g/AAUzayJplOcSq1 nFMqdCOFBw0pmOfTbT4ZxQZpNtG7rTfuRdsrWa9Jg1RefK5ojjjq66JDrgmdUUfgVsl2 pgbMoUBpyv1uqeD5WVozVHg8XDAkNCj4URWVQbITQkDFWyeCvYhMdBWjVGPeekJG6kyh 4yIA== X-Gm-Message-State: APjAAAVKvYEqImeMb9fbToyO2vHS+O8dGONnRjGf/7HlrZY1TyqFARzj IyYrOWLXwTuD7b/esEU1NpEAqER+eaETpSoD 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 Content-Type: text/plain; charset="UTF-8" Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org 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 --- 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; -- 2.21.0.1020.gf2820cf01a-goog