From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: [PATCH 1/2] iptables 32bit compat layer Date: 20 Feb 2006 22:23:25 +0100 Message-ID: References: <200602201110.39092.dim@openvz.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, netfilter-devel@lists.netfilter.org, rusty@rustcorp.com.au, akpm@osdl.org, devel@openvz.org Return-path: To: Mishin Dmitry In-Reply-To: <200602201110.39092.dim@openvz.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: netfilter-devel.vger.kernel.org Mishin Dmitry writes: > Hello, > > This patch set extends current iptables compatibility layer in order to get > 32bit iptables to work on 64bit kernel. Current layer is insufficient > due to alignment checks both in kernel and user space tools. > > This patch introduces base compatibility interface for other ip_tables modules Nice. But some issues with the implementation +#if defined(CONFIG_X86_64) +#define is_current_32bits() (current_thread_info()->flags & _TIF_IA32) This should be is_compat_task(). And we don't do such ifdefs in generic code. And what you actually need here is a is_compat_task_with_funny_u64_alignment() (better name sought) So I would suggest you add macros for that to the ia64 and x86-64 asm/compat.hs and perhaps a ARCH_HAS_FUNNY_U64_ALIGNMENT #define in there. + ret = 0; + switch (convert) { + case COMPAT_TO_USER: + pt = (struct ipt_entry_target *)target; etc. that looks ugly. why can't you just define different functions for that? We don't really need in kernel ioctl +#ifdef CONFIG_COMPAT + down(&compat_ipt_mutex); +#endif Why does it need an own lock? Overall the implementation looks very complicated. Are you sure it wasn't possible to do this simpler? -Andi