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 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 0EAA3C433EF for ; Thu, 21 Apr 2022 10:39:53 +0000 (UTC) Received: from localhost ([::1]:57314 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nhUE3-0000v2-Og for qemu-devel@archiver.kernel.org; Thu, 21 Apr 2022 06:39:51 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:43702) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nhU0G-00082t-Bk; Thu, 21 Apr 2022 06:25:37 -0400 Received: from kylie.crudebyte.com ([5.189.157.229]:50803) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nhU0D-0001VW-WE; Thu, 21 Apr 2022 06:25:35 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=crudebyte.com; s=kylie; h=Content-Type:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Content-ID:Content-Description; bh=fQk9GYzgdFeuEoy0SRsQi5ogDYwgQ+a8h1cIuIL075U=; b=AVZ+1+VEfuAhka355B+syp7KS2 KWr9J4A4B/v1ZyoLKW3n0sIbMRV7Y7NciYmKTVkV+W/0zlMTO6l2/SDZz5nMDS4v4n2gySakWpcx9 jBpFKw1SyjZuyTAmCRo/YirtvaIb9wBKawampVD5iaM3GH5Pfr3KTRVEvk2fvS1TpnHYfBFR8H+Fv pbmEOGuLsO7PmPYmn70q0BYbnJpe4+wONJD8AQkdp3si1KCybRTnw/R0ewHdZboyNz+2filNtxyBF +13O/89OLzmctvYww3/JrTOE5WIaIMdaU0p6gusOnWM5oq+MKFeTS+X7i6lmTxK8w+GJX5WuSdskS ct8mmMY/mtwJB/TFkg3pyAeebdDn1CZuuuLZijTd6f+aUnIw8wR00NctDRrd5ft3KUqjB47xHcCBC Fe3+gEOHS4nQoi4e6gTlOOQKW9cstcqrgy0ijjIshz3KYERotQlyR5uE71VwD+MjnXa+jrDNYB9fJ 3YuPxbGbn2DQLOhFcSKsH1bxIGM97arrc4cL329XmweiqJitAuXLBGpp1ZdCotoOK8xunFdWB3jG0 frzlMLEoYrKCtjKziNqhWGDqFLRK2XL9p5nVz/f7/voOuXXxtckMW9CIyXbKVFZoIiT9wwdAAfOvC NyaQHIDA34qRNn4VNu18+lqi1FEDpT7QjUEzEIpwc=; From: Christian Schoenebeck To: qemu-devel@nongnu.org, qemu-stable@nongnu.org Cc: Keno Fischer , Michael Roitzsch , Will Cohen , Akihiko Odaki , Greg Kurz Subject: Re: [PATCH 3/5] 9pfs: fix wrong encoding of rdev field in Rgetattr on macOS Date: Thu, 21 Apr 2022 12:25:23 +0200 Message-ID: <8971800.MWpjzubbLj@silver> In-Reply-To: <20220421093056.5ab1e7ed@bahia> References: <9db9268aac4eb87e1471ab8240109c7c29be3bef.1650370027.git.qemu_oss@crudebyte.com> <20220421093056.5ab1e7ed@bahia> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Received-SPF: pass client-ip=5.189.157.229; envelope-from=qemu_oss@crudebyte.com; helo=kylie.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_PASS=-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" On Donnerstag, 21. April 2022 09:30:56 CEST Greg Kurz wrote: > On Tue, 19 Apr 2022 13:41:15 +0200 > > Christian Schoenebeck wrote: > > 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. > > For the sake of accuracy : this is converting the host's dev_t to glibc's > format (MMMM_Mmmm_mmmM_MMmm, 64 bits) actually, which is compatible with > linux's format (mmmM_MMmm, 32 bits), as described in . You want me to put this to the commit log? > > Signed-off-by: Christian Schoenebeck > > --- > > > > hw/9pfs/9p.c | 37 ++++++++++++++++++++++++++++++++++++- > > 1 file changed, 36 insertions(+), 1 deletion(-) > > > > diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c > > index 225f31fc31..d953035e1c 100644 > > --- a/hw/9pfs/9p.c > > +++ b/hw/9pfs/9p.c > > @@ -1318,6 +1318,41 @@ static int32_t stat_to_iounit(const V9fsPDU *pdu, > > const struct stat *stbuf)> > > return blksize_to_iounit(pdu, stbuf->st_blksize); > > > > } > > > > +#if !defined(CONFIG_LINUX) > > + > > +/* > > + * Generates a Linux device number (a.k.a. dev_t) for given device major > > + * and minor numbers. > > + */ > > +static 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 uint64_t host_dev_to_dotl_dev(dev_t dev) > > +{ > > +#ifdef CONFIG_LINUX > > + return dev; > > +#else > > + return makedev_dotl(major(dev), minor(dev)); > > +#endif > > +} > > + > > It is a bit unfortunate to inflate 9p.c, which is large enough, with > glue code. Even if they are only used here, I'd personally put them > in 9p-util.h. No big deal. Makes sense, I'll move it. > Reviewed-by: Greg Kurz Thanks! > > static int stat_to_v9stat_dotl(V9fsPDU *pdu, const struct stat *stbuf, > > > > V9fsStatDotl *v9lstat) > > > > { > > > > @@ -1327,7 +1362,7 @@ 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;