From patchwork Mon Apr 25 12:20:49 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Schoenebeck X-Patchwork-Id: 12825732 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 10AB0C433F5 for ; Mon, 25 Apr 2022 12:44:06 +0000 (UTC) Received: from localhost ([::1]:34860 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1niy4S-0000kk-Uo for qemu-devel@archiver.kernel.org; Mon, 25 Apr 2022 08:44:04 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37152) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1niy2E-00069W-UD; Mon, 25 Apr 2022 08:41:46 -0400 Received: from lizzy.crudebyte.com ([91.194.90.13]:37153) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1niy2C-0002Ed-G7; Mon, 25 Apr 2022 08:41:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=crudebyte.com; s=lizzy; h=Cc:To:Subject:Date:From:References:In-Reply-To: Message-Id:Content-Type:Content-Transfer-Encoding:MIME-Version:Content-ID: Content-Description; bh=vq90Q4vtQmJgyHCseX/Xdws1yT3xxELHmtULnL9IalE=; b=miduV LNsXIVulmK1RA/BS9fdzWGKzotLPA9J8sgWsY5T7pTLrwiXRzR0uAaxhUoMFXvzdBZwdXoAgRUzxO HLk1SGFgPs2VZXvGY8ZiwnhbU62UAlnPUynR7xj0skI19pGDFkfMgNiKpJAxXHNhw85+Qu9ns9HgY LFkLx8l92EViXpSjkol7Qv2oNQjNkyD1eiy/U8U8HGO+GeUcipgj8HQFwwPF2xskDz3q+UDbqpUvd tDHjHfnSu4jIkhMLZjK4RYNLwJFxqUcmlB9Rd+gVh8kjMk8JdFxgj5s14oPVoRApjzx5mEx62/Awx pQhMf3UUfQ6PWdt1mZBJOruI1/Pzw==; Message-Id: In-Reply-To: References: From: Christian Schoenebeck Date: Mon, 25 Apr 2022 14:20:49 +0200 Subject: [PATCH v3 3/6] 9pfs: fix wrong encoding of rdev field in Rgetattr on macOS To: qemu-devel@nongnu.org Cc: Will Cohen , Greg Kurz , Michael Roitzsch , Keno Fischer , Akihiko Odaki , qemu-stable@nongnu.org Received-SPF: none client-ip=91.194.90.13; envelope-from=e0293bfec97b3ccf350f47903a4e8c8fc65d9826@lizzy.crudebyte.com; helo=lizzy.crudebyte.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_NONE=0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The 'rdev' field in 9p reponse 'Rgetattr' is of type dev_t, which is actually a system dependant type and therefore both the size and encoding of dev_t differ between macOS and Linux. So far we have sent 'rdev' to guest in host's dev_t format as-is, which caused devices to appear with wrong device numbers on guests running on macOS hosts, eventually leading to various misbehaviours on guest in conjunction with device files. This patch fixes this issue by converting the device number from host's dev_t format to Linux dev_t format. As 9p request 'Tgettattr' is exclusive to protocol version 9p2000.L, it should be fair to assume that 'rdev' field is assumed to be in Linux dev_t format by client as well. Signed-off-by: Christian Schoenebeck Link: https://lore.kernel.org/qemu-devel/20220421093056.5ab1e7ed@bahia/ Reviewed-by: Greg Kurz --- hw/9pfs/9p-util.h | 39 +++++++++++++++++++++++++++++++++++++++ hw/9pfs/9p.c | 2 +- 2 files changed, 40 insertions(+), 1 deletion(-) diff --git a/hw/9pfs/9p-util.h b/hw/9pfs/9p-util.h index 97e681e167..2cc9a5dbfb 100644 --- a/hw/9pfs/9p-util.h +++ b/hw/9pfs/9p-util.h @@ -19,6 +19,45 @@ #define O_PATH_9P_UTIL 0 #endif +#if !defined(CONFIG_LINUX) + +/* + * Generates a Linux device number (a.k.a. dev_t) for given device major + * and minor numbers. + * + * To be more precise: it generates a device number in glibc's format + * (MMMM_Mmmm_mmmM_MMmm, 64 bits) actually, which is compatible with + * Linux's format (mmmM_MMmm, 32 bits), as described in . + */ +static inline uint64_t makedev_dotl(uint32_t dev_major, uint32_t dev_minor) +{ + uint64_t dev; + + // from glibc sysmacros.h: + dev = (((uint64_t) (dev_major & 0x00000fffu)) << 8); + dev |= (((uint64_t) (dev_major & 0xfffff000u)) << 32); + dev |= (((uint64_t) (dev_minor & 0x000000ffu)) << 0); + dev |= (((uint64_t) (dev_minor & 0xffffff00u)) << 12); + return dev; +} + +#endif + +/* + * Converts given device number from host's device number format to Linux + * device number format. As both the size of type dev_t and encoding of + * dev_t is system dependant, we have to convert them for Linux guests if + * host is not running Linux. + */ +static inline uint64_t host_dev_to_dotl_dev(dev_t dev) +{ +#ifdef CONFIG_LINUX + return dev; +#else + return makedev_dotl(major(dev), minor(dev)); +#endif +} + #ifdef CONFIG_DARWIN #define qemu_fgetxattr(...) fgetxattr(__VA_ARGS__, 0, 0) #define qemu_lgetxattr(...) getxattr(__VA_ARGS__, 0, XATTR_NOFOLLOW) diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index 225f31fc31..4a296a0b94 100644 --- a/hw/9pfs/9p.c +++ b/hw/9pfs/9p.c @@ -1327,7 +1327,7 @@ static int stat_to_v9stat_dotl(V9fsPDU *pdu, const struct stat *stbuf, v9lstat->st_nlink = stbuf->st_nlink; v9lstat->st_uid = stbuf->st_uid; v9lstat->st_gid = stbuf->st_gid; - v9lstat->st_rdev = stbuf->st_rdev; + v9lstat->st_rdev = host_dev_to_dotl_dev(stbuf->st_rdev); v9lstat->st_size = stbuf->st_size; v9lstat->st_blksize = stat_to_iounit(pdu, stbuf); v9lstat->st_blocks = stbuf->st_blocks;