From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757215AbcHCIba (ORCPT ); Wed, 3 Aug 2016 04:31:30 -0400 Received: from mail-oi0-f52.google.com ([209.85.218.52]:33264 "EHLO mail-oi0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756777AbcHCIbX (ORCPT ); Wed, 3 Aug 2016 04:31:23 -0400 MIME-Version: 1.0 In-Reply-To: References: <20160803004226.GF2356@ZenIV.linux.org.uk> From: Richard Weinberger Date: Wed, 3 Aug 2016 10:30:16 +0200 Message-ID: Subject: Re: Please don't replace numeric parameter like 0444 with macro To: Konstantin Khlebnikov Cc: Al Viro , Linus Torvalds , Greg Kroah-Hartman , Heiko Carstens , Russell King - ARM Linux , Linux Kernel Mailing List , Baole Ni , Pavel Machek , chuansheng.liu@intel.com, "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 3, 2016 at 10:07 AM, Konstantin Khlebnikov wrote: > On Wed, Aug 3, 2016 at 3:42 AM, Al Viro wrote: >> On Tue, Aug 02, 2016 at 04:58:29PM -0400, Linus Torvalds wrote: >>> [ So I answered similarly to another patch, but I'll just re-iterate >>> and change the subject line so that it stands out a bit from the >>> millions of actual patches ] >>> >>> On Tue, Aug 2, 2016 at 1:42 PM, Pavel Machek wrote: >>> > >>> > Everyone knows what 0644 is, but noone can read S_IRUSR | S_IWUSR | >>> > S_IRCRP | S_IROTH (*). Please don't do this. >>> >>> Absolutely. It's *much* easier to parse and understand the octal >>> numbers, while the symbolic macro names are just random line noise and >>> hard as hell to understand. You really have to think about it. >>> >>> So we should rather go the other way: convert existing bad symbolic >>> permission bit macro use to just use the octal numbers. >>> >>> The symbolic names are good for the *other* bits (ie sticky bit, and >>> the inode mode _type_ numbers etc), but for the permission bits, the >>> symbolic names are just insane crap. Nobody sane should ever use them. >>> Not in the kernel, not in user space. >> >> Except that you are inviting the mixes like S_IFDIR | 17 /* oops, should've >> been 017, or do we spell it 0017? */ that way. I certainly agree that this >> patch series had been a huge pile of manure, but "let's convert it in other >> direction" is inviting pretty much the same thing, with lovely potential for >> typos, etc. > > We could add several macro with readable names for really used rwx > combinations, like: > > #define KERN_SECRET_RO 0400 > #define KERN_SECRET_RW 0600 > #define KERN_SECRET_WO 0200 > #define KERN_SECRET_DIR 0500 > > #define KERN_PUBLIC_RO 0444 > #define KERN_PUBLIC_RW 0644 > #define KERN_PUBLIC_DIR 0555 > > #define KERN_UNSAFE_RW 0666 > #define KERN_UNSAFE_WO 0222 > #define KERN_UNSAFE_DIR 0777 Or just keep it as-is, everybody can read them. Why do we have to hide all kind of numbers behind CPP macros? Is this a thing these days? -- Thanks, //richard