From patchwork Wed Jun 12 11:43:22 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 10989643 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 583D613AF for ; Wed, 12 Jun 2019 11:45:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 459DE2894D for ; Wed, 12 Jun 2019 11:45:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3926C28A2E; Wed, 12 Jun 2019 11:45:13 +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 D33BC2894D for ; Wed, 12 Jun 2019 11:45:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2438411AbfFLLny (ORCPT ); Wed, 12 Jun 2019 07:43:54 -0400 Received: from mail-qk1-f201.google.com ([209.85.222.201]:39985 "EHLO mail-qk1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2438402AbfFLLnx (ORCPT ); Wed, 12 Jun 2019 07:43:53 -0400 Received: by mail-qk1-f201.google.com with SMTP id n5so13501991qkf.7 for ; Wed, 12 Jun 2019 04:43:53 -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=lneYlz8LHaEiU1JdbWuWSlmR06MpCpkboyQbci6TbSY=; b=ZYQEd649LLsr0eo67tg5mBkc6yqoxRRkUvXmz72kCnd/9DceAYIH632RHTy/L9FYgN XB0cqiUT3202g16B44AOr6KGjUuUQCuOjjfhX/1rdyfTYvOLIoAOYVJQEyUECaYKw2EI wRT/I+bn5+fj2NWK1Uq2bsCtdk4XPg+CFAKbAVJ1PN2JQI+rUil/RmfEGI1P+fH7HVvB bi61I1IZdPLHbF9O0x6GFnVgN1H+PpiOuX7A6ltMyEW2b4fJxpc44OPAWrBW3bGwUHZL UOaZyEvgJIbhkL4J+WjiYsF7XS5CEf84amjDEh8dkaorHVY5qClgPk6YQHyQ5aqjEpT+ PVjA== 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=lneYlz8LHaEiU1JdbWuWSlmR06MpCpkboyQbci6TbSY=; b=RWGudfF85nuKuFzzssIFf7LnHCiTitjC/98kyLKRRfOd0IT8AEXXi4UC8RzSXYXJJo mrA28pSFdvHccwoZiZlPPBsC8unjzJR9ELMWYlmeoR9MaOCd7EoC3uw3w6MrfLoyZbt9 5YYg7L/kkMpqrN5IgiklD3/1qyJdp4Anq7sQHnsM25vNYCOXfpVN8pDEiDsuAdQRq8YF ej1+Leq+Bu2i7nfuzKw4j9P+KMNlVk7iW6OPUP4eF5CiunG5eQj0m+QSDaPRJqozESWH 0fE7ltITyZsV4IWKJ7ydYpDSrVo64WfpWGKxi2/3XhU5SbjvlM5T/yF0g64MRNM2rDP7 iKvA== X-Gm-Message-State: APjAAAUYM167VabWKktY15dcGbDqD99y2H8Vu+4r5koBj5gQXSb06EAC gJT3633UKHILN0LzUO+TLscACK2W8fDAUrgb X-Google-Smtp-Source: APXvYqycBZ/jgN95w1hvszVcRcdW7P9Dg7ub2DyBfBHGpLBHXa9MwJ+9kmDh7H9YZkcwArOGpwiZYJEXckCXcJ6D X-Received: by 2002:a37:a5d5:: with SMTP id o204mr25506301qke.155.1560339832693; Wed, 12 Jun 2019 04:43:52 -0700 (PDT) Date: Wed, 12 Jun 2019 13:43:22 +0200 In-Reply-To: Message-Id: <8f65548bef8544d49980a92d221b74440d544c1e.1560339705.git.andreyknvl@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.22.0.rc2.383.gf4fbbf30c2-goog Subject: [PATCH v17 05/15] 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 , 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 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. Reviewed-by: Kees Cook Reviewed-by: Catalin Marinas Signed-off-by: Andrey Konovalov Reviewed-by: Vincenzo Frascino Reviewed-by: Khalid Aziz --- 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;