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=-16.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 26150C43613 for ; Mon, 24 Jun 2019 14:34:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F157D208E4 for ; Mon, 24 Jun 2019 14:34:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="icIOyvO3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729171AbfFXOdW (ORCPT ); Mon, 24 Jun 2019 10:33:22 -0400 Received: from mail-vk1-f202.google.com ([209.85.221.202]:56989 "EHLO mail-vk1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729133AbfFXOdU (ORCPT ); Mon, 24 Jun 2019 10:33:20 -0400 Received: by mail-vk1-f202.google.com with SMTP id a4so6416098vki.23 for ; Mon, 24 Jun 2019 07:33:20 -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=WdcdmcPYcZL0TsO1VpqXvB5XTsCD4Aa27drvhQYmelM=; b=icIOyvO3zCCmb1V8FS7xfJSkpaqM0fPXCTMb8P53l/4sddyw376GFk7VntBpgH40Jb dlVT0eEdK1fq5jmQgL2mnnKbFXpBzrZuKvOPspNemignJXsBOcwCLAzIsieht3b/IonX 6zR53XzWDMowl976raMoG4ND2r1RJIjiKAB3ytw9JQwx/injyU+afKGG9i0hRkWS9CDw EATvoJg1LGBCFewFDqj3C9titqpFuwNcjn3ZH++ykTRmRXVgWgXvHOfj+CupsqyAB/Yo cDDXvnZegW7qBTu946VpVm0cbCpkrGmZnjcy3KK2CuBZhA9rQZ6St5/hoz/kt5af2Epi DXZw== 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=WdcdmcPYcZL0TsO1VpqXvB5XTsCD4Aa27drvhQYmelM=; b=FDflPIwScZ0GZWZgP6oXvNU5CuZtVQnIT1yprwq66TVexr6u47u0izvoSv5yDKeoqZ bnQzUeW573Bax5VyZ02+n7REsRuBRj7G05U5/z0aLmpqcNCB96bQos9ybquGhGpvVVj6 7cZROG5OQ2xjirmNoEDxVly3auhis7Wte4JUZqZTHWA7IgTSkqWq2Of+AEALdlNYxHJG TBLm8u2T+pPdi/RCuznDrfxu+DZjL+CRB3YFWjBNJc8RGiL/GV7ZyI7r29OGQjrYgsln kaCbGpGa+nvgAY7/KcN8BFW69eg1hYGT/qoqRSb++YBE7kUWKYQuQeU2NDx6d4IbYsMR ufzQ== X-Gm-Message-State: APjAAAUW3WZwVOBsawXicBltv9vfGICYrDDjN5D4fd3DYGV8zGtjYUGZ pIDpJBCF9kWELSmyokqIjh7dpQdFVDIRY0YK X-Google-Smtp-Source: APXvYqyeP684NrNNIM3KhbFTQXwcDTrmwl6IHcjELxzf0coSdSlRrTjZ+0PmPJg+BCNxcMTgBBiBdQWJwdq50pfN X-Received: by 2002:a1f:ccc4:: with SMTP id c187mr4784377vkg.56.1561386799794; Mon, 24 Jun 2019 07:33:19 -0700 (PDT) Date: Mon, 24 Jun 2019 16:32:50 +0200 In-Reply-To: Message-Id: <3f5c63a871c652369d3cf7741499d1d65413641c.1561386715.git.andreyknvl@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.22.0.410.gd8fdbe21b5-goog Subject: [PATCH v18 05/15] mm: 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 , Luc Van Oostenryck , Dave Martin , Khalid Aziz , enh , Jason Gunthorpe , Christoph Hellwig , Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Robin Murphy , 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 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. Reviewed-by: Khalid Aziz Reviewed-by: Vincenzo Frascino Reviewed-by: Kees Cook Reviewed-by: Catalin Marinas 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 ddde097cf9e4..c37df3d455a2 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -802,6 +802,8 @@ 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)); /* @@ -964,6 +966,8 @@ 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; -- 2.22.0.410.gd8fdbe21b5-goog