From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764881AbZLQQqY (ORCPT ); Thu, 17 Dec 2009 11:46:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1764802AbZLQQqU (ORCPT ); Thu, 17 Dec 2009 11:46:20 -0500 Received: from one.firstfloor.org ([213.235.205.2]:49931 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756652AbZLQQqT (ORCPT ); Thu, 17 Dec 2009 11:46:19 -0500 Date: Thu, 17 Dec 2009 17:46:14 +0100 From: Andi Kleen To: "Eric W. Biederman" Cc: Andi Kleen , akpm@linux-foundation.org, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] SYSCTL: Fix sysctl breakage on systems with older glibc Message-ID: <20091217164614.GI9804@basil.fritz.box> References: <20091216112844.GA31705@basil.fritz.box> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 17, 2009 at 07:07:54AM -0800, Eric W. Biederman wrote: > reaction would be. If it makes logging in and manually using the > machine unbearable on systems with versions of glibc from days of > yore, the level of logging is too high. The reason I was slightly annoyed is because I flagged this during code review and it wasn't addressed before merging. > > > I see this on a SUSE 10.0 system with glibc 2.3.5. > > Don't warn for this common case. > > Perhaps it is just my sample of the world but glibc < 2.5 isn't > common, especially on machines that I am putting new kernels on. > Equally machines with 3+ year old installs are rare. Linux simply cannot abandon older user land. We still (near) fully support a.out executables, even on 64bit. > > > Signed-off-by: Andi Kleen > > > > diff -u linux-2.6.32-git12/kernel/sysctl_binary.c-o linux-2.6.32-git12/kernel/sysctl_binary.c > > --- linux-2.6.32-git12/kernel/sysctl_binary.c-o 2009-12-16 12:15:52.000000000 +0100 > > +++ linux-2.6.32-git12/kernel/sysctl_binary.c 2009-12-16 12:14:58.000000000 +0100 > > @@ -1399,6 +1399,13 @@ > > { > > int i; > > > > + /* > > + * CTL_KERN/KERN_VERSION is used by older glibc and cannot > > + * ever go away. > > + */ > The comment is wrong. Older versions of glibc are perfectly happy > getting -ENOSYS form sys_sysctl. and it fills and fills and fills the kernel log. In practice that's not usable. > > > + if (name[0] == CTL_KERN && name[1] == KERN_VERSION) > > + return; > > If you make it printk_once for this case I think that strikes the right > balance. You won't be spammed to death by messages telling you about > a silly old glibc, but you will be told. It's not a "silly old glibc", it's a "perfectly functional old glibc" -Andi -- ak@linux.intel.com -- Speaking for myself only.