From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759572AbXJDRfp (ORCPT ); Thu, 4 Oct 2007 13:35:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756659AbXJDRfi (ORCPT ); Thu, 4 Oct 2007 13:35:38 -0400 Received: from uni20mr.unity.ncsu.edu ([152.1.2.39]:52519 "EHLO uni20mr.unity.ncsu.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756303AbXJDRfh (ORCPT ); Thu, 4 Oct 2007 13:35:37 -0400 Message-ID: <47052458.2090600@ncsu.edu> Date: Thu, 04 Oct 2007 13:35:20 -0400 From: Casey Dahlin User-Agent: Thunderbird 2.0.0.5 (X11/20070727) MIME-Version: 1.0 To: Christoph Hellwig , Casey Dahlin , linux-kernel@vger.kernel.org Subject: Re: [PATCH] Code style fix for open_exec References: <47045299.2000601@ncsu.edu> <20071004070857.GB21481@infradead.org> In-Reply-To: <20071004070857.GB21481@infradead.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-PMX-Version: 5.3.3.310218, Antispam-Engine: 2.5.2.313940, Antispam-Data: 2007.10.4.101133 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Christoph Hellwig wrote: > On Wed, Oct 03, 2007 at 10:40:25PM -0400, Casey Dahlin wrote: > >> From d2a6c5d29dc34cfea892124ab72b4eb55d2f8a80 Mon Sep 17 00:00:00 2001 >> From: Casey Dahlin >> Date: Wed, 3 Oct 2007 22:01:49 -0400 >> Subject: [PATCH] Code style fix for open_exec >> >> Fix a horribly mangled 5 level indent and severe abuse of goto in the >> open_exec >> function. >> > > While the function is not nice your version makes it even worse. > Ouch :) I don't think I did so bad. > Try this one instead which has been in my pending testing tree for a while: > Pretty much all of the stylistic changes were recommended to me already off list by Joe Perches. I have that in my branch now, and was waiting on any further feedback before resubmitting. There's a couple of things here though (particularly the unlikelys) that are worth having. This is the better code. > > > Index: linux-2.6/fs/exec.c > =================================================================== > --- linux-2.6.orig/fs/exec.c 2007-09-16 20:29:01.000000000 +0200 > +++ linux-2.6/fs/exec.c 2007-09-16 20:29:56.000000000 +0200 > @@ -669,41 +669,55 @@ EXPORT_SYMBOL(setup_arg_pages); > > #endif /* CONFIG_MMU */ > > +/** > + * open_exec - open file for execution > + * @name: filename to open > + * > + * Open the file pointed to by @filename in the current namespace > + * for execution. Error out if the file is not a regular file or > + * this mount does not allow executing files on it. > + */ > struct file *open_exec(const char *name) > { > struct nameidata nd; > - int err; > struct file *file; > + int err; > > - err = path_lookup_open(AT_FDCWD, name, LOOKUP_FOLLOW, &nd, FMODE_READ|FMODE_EXEC); > - file = ERR_PTR(err); > + err = path_lookup_open(AT_FDCWD, name, LOOKUP_FOLLOW, &nd, > + FMODE_READ|FMODE_EXEC); > + if (unlikely(err)) > + goto out; > > - if (!err) { > - struct inode *inode = nd.dentry->d_inode; > - file = ERR_PTR(-EACCES); > - if (!(nd.mnt->mnt_flags & MNT_NOEXEC) && > - S_ISREG(inode->i_mode)) { > - int err = vfs_permission(&nd, MAY_EXEC); > - file = ERR_PTR(err); > - if (!err) { > - file = nameidata_to_filp(&nd, O_RDONLY); > - if (!IS_ERR(file)) { > - err = deny_write_access(file); > - if (err) { > - fput(file); > - file = ERR_PTR(err); > - } > - } > -out: > - return file; > - } > - } > - release_open_intent(&nd); > - path_release(&nd); > + err = -EACCES; > + if (unlikely(nd.mnt->mnt_flags & MNT_NOEXEC)) > + goto out_path_release; > + if (unlikely(!S_ISREG(nd.dentry->d_inode->i_mode))) > + goto out_path_release; > + > + err = vfs_permission(&nd, MAY_EXEC); > + if (unlikely(err)) > + goto out_path_release; > + > + file = nameidata_to_filp(&nd, O_RDONLY); > + if (unlikely(IS_ERR(file))) { > + err = PTR_ERR(file); > + goto out; > + } > + > + err = deny_write_access(file); > + if (unlikely(err)) { > + fput(file); > + goto out; > } > - goto out; > -} > > + return file; > + > + out_path_release: > + release_open_intent(&nd); > + path_release(&nd); > + out: > + return ERR_PTR(err); > +} > EXPORT_SYMBOL(open_exec); > > int kernel_read(struct file *file, unsigned long offset, > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >