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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 7B100C433DB for ; Wed, 17 Feb 2021 10:22:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3FACE64E6B for ; Wed, 17 Feb 2021 10:22:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230389AbhBQKWE (ORCPT ); Wed, 17 Feb 2021 05:22:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51866 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232305AbhBQKV4 (ORCPT ); Wed, 17 Feb 2021 05:21:56 -0500 Received: from mail-ua1-x935.google.com (mail-ua1-x935.google.com [IPv6:2607:f8b0:4864:20::935]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 313E2C061756 for ; Wed, 17 Feb 2021 02:21:16 -0800 (PST) Received: by mail-ua1-x935.google.com with SMTP id 67so4374399uao.1 for ; Wed, 17 Feb 2021 02:21:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=szeredi.hu; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=x7YMLJjk40HzAWELqN5l9m4d4X7by6+aJQrjOvMUw0Q=; b=aBwQ8vyyLXdPiYxmIPMn+u8n+zN5eUz3evKEEiKLz4mVAKmiI3e66LQTfkGf+EtYqd kDoQCHP6JkV0WZmQjMXp/DFk/mneY+9FkiRtxShWfVzgVmy1nU7k4IGY9g4VzYAS1tw6 i4evrmjCbdiZVTlI8LSS19oFCVD42xFpHt/vE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=x7YMLJjk40HzAWELqN5l9m4d4X7by6+aJQrjOvMUw0Q=; b=sa6UxHSfQJc/uSsgQkATgR6UaOD51At8xRZpQE+4JZ9YkKAYDm95rc/PF9NY1GuVpN ThQoc53JqF682eWv89T9BkINmstm4dCpIbbdg8c/VjdROUzU4dcUqz+E1QHibx3WC+nx EPsNEw7zDW62lKiG+xmuGe8jPVBa/oSfY7nkM8gXAXTxZI4R133DS6D9fyOM67DSJIXJ FAtGzu6hgZEaye0RZclT8tBS7kr/SKqBQEXAJXsCudv4SXda+eX5SnLNGvjjf5sh888j /Y0kSg0hjEMU4eBybUfLlRPkagQ35fWEYb+G9fKtYcKNYOwJYj/HUZO5d/GeeKicqDcF KVGw== X-Gm-Message-State: AOAM533ftdjMHSLQ6uvqxFbH8NT9aZjYFnewx98qu10pZOZi4x+lPyvl 2DtRP1fjPepq2JwAKTASopXOEKSoN/iuMHuIDpeB5g== X-Google-Smtp-Source: ABdhPJxdVSmVC0ekPz8wTrSzRpU2MiWtMKZ1ompaYpQbNmbqIQDp0GCUYwVDtImw65OrCd5+hdowI4DEury0KzWA24A= X-Received: by 2002:ab0:5963:: with SMTP id o32mr14151409uad.11.1613557275372; Wed, 17 Feb 2021 02:21:15 -0800 (PST) MIME-Version: 1.0 References: <20210125153057.3623715-1-balsini@android.com> <20210125153057.3623715-3-balsini@android.com> In-Reply-To: <20210125153057.3623715-3-balsini@android.com> From: Miklos Szeredi Date: Wed, 17 Feb 2021 11:21:04 +0100 Message-ID: Subject: Re: [PATCH RESEND V12 2/8] fuse: 32-bit user space ioctl compat for fuse device To: Alessio Balsini Cc: Akilesh Kailash , Amir Goldstein , Antonio SJ Musumeci , David Anderson , Giuseppe Scrivano , Jann Horn , Jens Axboe , Martijn Coenen , Palmer Dabbelt , Paul Lawrence , Peng Tao , Stefano Duo , Zimuzo Ezeozue , wuyan , fuse-devel , kernel-team , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon, Jan 25, 2021 at 4:31 PM Alessio Balsini wrote: > > With a 64-bit kernel build the FUSE device cannot handle ioctl requests > coming from 32-bit user space. > This is due to the ioctl command translation that generates different > command identifiers that thus cannot be used for direct comparisons > without proper manipulation. > > Explicitly extract type and number from the ioctl command to enable > 32-bit user space compatibility on 64-bit kernel builds. > > Signed-off-by: Alessio Balsini > --- > fs/fuse/dev.c | 29 ++++++++++++++++++----------- > include/uapi/linux/fuse.h | 3 ++- > 2 files changed, 20 insertions(+), 12 deletions(-) > > diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c > index 588f8d1240aa..ff9f3b83f879 100644 > --- a/fs/fuse/dev.c > +++ b/fs/fuse/dev.c > @@ -2233,37 +2233,44 @@ static int fuse_device_clone(struct fuse_conn *fc, struct file *new) > static long fuse_dev_ioctl(struct file *file, unsigned int cmd, > unsigned long arg) > { > - int err = -ENOTTY; > + int res; > + int oldfd; > + struct fuse_dev *fud = NULL; > > - if (cmd == FUSE_DEV_IOC_CLONE) { > - int oldfd; > + if (_IOC_TYPE(cmd) != FUSE_DEV_IOC_MAGIC) > + return -EINVAL; Why change ENOTTY to EINVAL? Thanks, MIklos