From patchwork Wed Mar 20 14:51:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 10861889 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 8BD1D13B5 for ; Wed, 20 Mar 2019 14:52:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 716B429D7E for ; Wed, 20 Mar 2019 14:52:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 64FFC29D83; Wed, 20 Mar 2019 14:52:03 +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 F0CF029D7E for ; Wed, 20 Mar 2019 14:52:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728436AbfCTOwB (ORCPT ); Wed, 20 Mar 2019 10:52:01 -0400 Received: from mail-yw1-f74.google.com ([209.85.161.74]:47133 "EHLO mail-yw1-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728419AbfCTOwA (ORCPT ); Wed, 20 Mar 2019 10:52:00 -0400 Received: by mail-yw1-f74.google.com with SMTP id c188so3391380ywf.14 for ; Wed, 20 Mar 2019 07:52:00 -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=LfpjTjIWpAUqgBuBr+ROlRDq3TWjVWHbA3wqyLv7Gqg=; b=aEInHw6BmCYYrnLC9PZfamaP8mF0QEG6bCjPXX9eR1nz2FAxuz8AakcoBGofdWpDDO ecVj+WVvAcyIM/4jHbYKbWN9FEhIYhxx/aKOkZgY6J++xI42I0q0BxFc8HG1MgmsuX4p FgBukYgteSls5KRVIf9LdhyXrtbiuThjGHXpsr95ebbSY1J3++E89dF2htIPvvI1/DzR SYS+4UXKzfCBY88MgyuqrkPh/UK28DK8ANz0pzTScNriptvjxadnhKInYAl8KyI7hS2W ag76Sj+PtN/agIm/Cl1LRWjUtui4zCqqh5CFVGbEGTMZA2YuLM4VLbRUKwjvD9UBYhzt x9aQ== 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=LfpjTjIWpAUqgBuBr+ROlRDq3TWjVWHbA3wqyLv7Gqg=; b=f+RvGdTS1irx/dAUrYkXEfDhxZlM2zDDV3qSQdU+nrO6KKzla4rWDYUttA+DANmGts jHqBnlvXAcUMEmL6Xx9r+6pjoz0XE/8o3hUJPGXOxZzVgIezjROFg5qT9nUXrkc63wUi NaRTmumYzG2qDUuTlPhmU7x6/U6XZAUjNtQs4mic+/D0arNYcggEX43lSbUhWClsyYRx 1MRe3LSjOLvI4k7ZsFgK4OAj5g4cXMkxkNv0RNV/wYWPodoUV3CSsv4wExlQ+6nMVW6d gzm2ergC73Hzy4AdeRgiQxbfDbhmaJf7mHRrlKfOJc1DFFhlKsJCfnjbMONS7IgNssWe Dx7w== X-Gm-Message-State: APjAAAXODFNvYfMgEsgkjiS3xuifJwbeSMu2gkS2c/4WAbmwuCUxuygX +ccWeIv/Xiw+OrZA7dpEeessTH8i5B7lLFJS X-Google-Smtp-Source: APXvYqxWvfeu7/LSMKKYKhkYxK38R+2YVgnBYPzEJZ3bjv+W/V6SCf9AmAnMy/L0N0KnMLwcoOG80tlOQ6HUd2Ol X-Received: by 2002:a81:994d:: with SMTP id q74mr2209556ywg.18.1553093519515; Wed, 20 Mar 2019 07:51:59 -0700 (PDT) Date: Wed, 20 Mar 2019 15:51:19 +0100 In-Reply-To: Message-Id: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.21.0.225.g810b269d1ac-goog Subject: [PATCH v13 05/20] mm, arm64: untag user pointers in mm/gup.c From: Andrey Konovalov To: Catalin Marinas , Will Deacon , Mark Rutland , Robin Murphy , Kees Cook , Kate Stewart , Greg Kroah-Hartman , Andrew Morton , Ingo Molnar , "Kirill A . Shutemov" , Shuah Khan , Vincenzo Frascino , Eric Dumazet , "David S. Miller" , Alexei Starovoitov , Daniel Borkmann , Steven Rostedt , Ingo Molnar , Peter Zijlstra , Arnaldo Carvalho de Melo , Alex Deucher , " =?utf-8?q?Christian_K=C3=B6nig?= " , "David (ChunMing) Zhou" , Yishai Hadas , Mauro Carvalho Chehab , Jens Wiklander , Alex Williamson , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, netdev@vger.kernel.org, bpf@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, linux-kernel@vger.kernel.org Cc: Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Chintan Pandya , Luc Van Oostenryck , Dave Martin , Kevin Brodsky , Szabolcs Nagy , Andrey Konovalov Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@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 --- mm/gup.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/gup.c b/mm/gup.c index f84e22685aaa..3192741e0b3a 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -686,6 +686,8 @@ 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)); /* @@ -848,6 +850,8 @@ 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;