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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 3AC12C742A8 for ; Fri, 12 Jul 2019 04:34:14 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 050C520863 for ; Fri, 12 Jul 2019 04:34:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="S2+HQhse" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 050C520863 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zeniv.linux.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=5uvwB21YI/t8NsnpVxflk9RGeOwRUHu2EQw0IZMrf4c=; b=S2+HQhse/2C5hn GWElPwoX0QMz+wl5p/fFZWLSMuEqvW+TE9o4cP3+FvkLtxiCabkb9xjfzWWAEVUlS5SaNd1+oV3g9 /G/rXCBcPAVxXFxck1IGn1iZ3yGJakiqx3qDr3WH7GbMoh5CuaYruM9uTt3GdlUqxidwYwjFfPCma gfn8fGnl5zd8k/aLVLJiyryBd1kjnm3To1Pv5r6U/HkGeBQG97YvCfDzxkkn3qp60T+DF+6/wWfps TnIgIPilTi505q/wEUCRRBrugDkSwb3lEgYqQG/4mDrzV8qb3GVLg32MFVdPrQhcHpBUN3Eouocei oCDi9PnicuNSUP4BAFjA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hlnG9-00075v-E5; Fri, 12 Jul 2019 04:34:13 +0000 Received: from zeniv.linux.org.uk ([195.92.253.2]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hlnG6-00074x-7X for linux-arm-kernel@lists.infradead.org; Fri, 12 Jul 2019 04:34:11 +0000 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92 #3 (Red Hat Linux)) id 1hlnFe-0003Rz-Ja; Fri, 12 Jul 2019 04:33:42 +0000 Date: Fri, 12 Jul 2019 05:33:42 +0100 From: Al Viro To: Aleksa Sarai Subject: Re: [PATCH v9 05/10] namei: O_BENEATH-style path resolution flags Message-ID: <20190712043341.GI17978@ZenIV.linux.org.uk> References: <20190706145737.5299-1-cyphar@cyphar.com> <20190706145737.5299-6-cyphar@cyphar.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190706145737.5299-6-cyphar@cyphar.com> User-Agent: Mutt/1.11.3 (2019-02-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190711_213410_270307_3D961444 X-CRM114-Status: GOOD ( 11.22 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, Alexei Starovoitov , linux-kernel@vger.kernel.org, David Howells , linux-kselftest@vger.kernel.org, sparclinux@vger.kernel.org, Shuah Khan , linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, Tycho Andersen , Aleksa Sarai , linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-xtensa@linux-xtensa.org, Kees Cook , Arnd Bergmann , Jann Horn , linuxppc-dev@lists.ozlabs.org, linux-m68k@lists.linux-m68k.org, Andy Lutomirski , Shuah Khan , David Drysdale , Christian Brauner , "J. Bruce Fields" , linux-parisc@vger.kernel.org, linux-api@vger.kernel.org, Chanho Min , Jeff Layton , Oleg Nesterov , Eric Biederman , linux-alpha@vger.kernel.org, linux-fsdevel@vger.kernel.org, Andrew Morton , Linus Torvalds , containers@lists.linux-foundation.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sun, Jul 07, 2019 at 12:57:32AM +1000, Aleksa Sarai wrote: > @@ -1442,8 +1464,11 @@ static int follow_dotdot_rcu(struct nameidata *nd) > struct inode *inode = nd->inode; > > while (1) { > - if (path_equal(&nd->path, &nd->root)) > + if (path_equal(&nd->path, &nd->root)) { > + if (unlikely(nd->flags & LOOKUP_BENEATH)) > + return -EXDEV; > @@ -1468,6 +1493,8 @@ static int follow_dotdot_rcu(struct nameidata *nd) > return -ECHILD; > if (&mparent->mnt == nd->path.mnt) > break; > + if (unlikely(nd->flags & LOOKUP_XDEV)) > + return -EXDEV; > /* we know that mountpoint was pinned */ > nd->path.dentry = mountpoint; > nd->path.mnt = &mparent->mnt; > @@ -1482,6 +1509,8 @@ static int follow_dotdot_rcu(struct nameidata *nd) > return -ECHILD; > if (!mounted) > break; > + if (unlikely(nd->flags & LOOKUP_XDEV)) > + return -EXDEV; Are you sure these failure exits in follow_dotdot_rcu() won't give suprious hard errors? > + if (unlikely(nd->flags & LOOKUP_BENEATH)) { > + error = dirfd_path_init(nd); > + if (unlikely(error)) > + return ERR_PTR(error); > + nd->root = nd->path; > + if (!(nd->flags & LOOKUP_RCU)) > + path_get(&nd->root); > + } > if (*s == '/') { > if (likely(!nd->root.mnt)) > set_root(nd); > @@ -2350,9 +2400,11 @@ static const char *path_init(struct nameidata *nd, unsigned flags) > s = ERR_PTR(error); > return s; > } > - error = dirfd_path_init(nd); > - if (unlikely(error)) > - return ERR_PTR(error); > + if (likely(!nd->path.mnt)) { Is that a weird way of saying "if we hadn't already called dirfd_path_init()"? _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel