Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761500AbbKUSyr (ORCPT ); Sat, 21 Nov 2015 13:54:47 -0500 Received: from Chamillionaire.breakpoint.cc ([80.244.247.6]:53595 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752787AbbKUSyp (ORCPT ); Sat, 21 Nov 2015 13:54:45 -0500 Date: Sat, 21 Nov 2015 19:54:19 +0100 From: Florian Westphal To: Tejun Heo Cc: Florian Westphal , davem@davemloft.net, pablo@netfilter.org, kaber@trash.net, kadlec@blackhole.kfki.hu, daniel@iogearbox.net, daniel.wagner@bmw-carit.de, nhorman@tuxdriver.co, lizefan@huawei.com, hannes@cmpxchg.org, netdev@vger.kernel.org, netfilter-devel@vger.kernel.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, ninasc@fb.com, Neil Horman , Jan Engelhardt Subject: Re: [PATCH 9/9] netfilter: implement xt_cgroup cgroup2 path match Message-ID: <20151121185419.GD25336@breakpoint.cc> References: <1448122441-9335-1-git-send-email-tj@kernel.org> <1448122441-9335-10-git-send-email-tj@kernel.org> <20151121165605.GC25336@breakpoint.cc> <20151121170425.GD3428@htj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151121170425.GD3428@htj.duckdns.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1312 Lines: 33 Tejun Heo wrote: > On Sat, Nov 21, 2015 at 05:56:06PM +0100, Florian Westphal wrote: > > > +struct xt_cgroup_info_v1 { > > > + __u8 has_path; > > > + __u8 has_classid; > > > + __u8 invert_path; > > > + __u8 invert_classid; > > > + char path[PATH_MAX]; > > > + __u32 classid; > > > + > > > + /* kernel internal data */ > > > + void *priv __attribute__((aligned(8))); > > > +}; > > > > Ahem. Am I reading this right? This struct is > 4k in size? > > If so -- Ugh. Does sizeof(path) really have to be PATH_MAX? > > Hmmm... yeap but would this be an acutual problem? Since rule blob can be allocated via vmalloc i guess "no", its not really a problem unless someone needs realy insane amount of such rules. I don't have any better suggestion, so I guess its necessary evil. The only other question I have is wheter PATH_MAX might be a possible ABI breaker in future. It would have to be guaranteed that this is the same size forever, else you'd get strange errors on rule insertion if the sizes of the kernel and userspace version differs. -- 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/