From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bernard Pidoux Subject: Re: [PATCH] ax25.h unsigned long type for ax25 timers Date: Fri, 20 Jun 2008 00:38:23 +0200 Message-ID: <485ADFDF.1070509@free.fr> References: <200806171504.38702.bpidoux@free.fr> <20080617.223050.266166325.davem@davemloft.net> <485A893E.4080405@free.fr> <20080619.144621.120746379.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Cc: ralf@linux-mips.org, linux-hams@vger.kernel.org, netdev@vger.kernel.org To: David Miller Return-path: In-Reply-To: <20080619.144621.120746379.davem@davemloft.net> Sender: linux-hams-owner@vger.kernel.org List-Id: netdev.vger.kernel.org David, Your explanation is perfectly clear and I understand the problem now. Thank you very much for taking the time to explain me that. Bernard Pidoux David Miller wrote: > From: Bernard Pidoux > Date: Thu, 19 Jun 2008 18:28:46 +0200 > >> Unfortunately I don't quite understand exactly why a structure in user >> space cannot be changed. > > Because there are userland binaries already compiled out there using > the current structure layout. If we change the kernel, those binaries > stop using a datastructure that matches what the kernel is using. > Such binaries will break. > > In generic, because of this, you can never change the layout of a > data structure exported to userland as a kernel interface. > >