From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jari Sundell" Subject: Re: [take12 0/3] kevent: Generic event handling mechanism. Date: Wed, 23 Aug 2006 11:49:22 +0200 Message-ID: References: <20060822231129.GA18296@ms2.inr.ac.ru> <20060822.173200.126578369.davem@davemloft.net> <20060823065659.GC24787@2ka.mipt.ru> <20060823083859.GA8936@2ka.mipt.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "David Miller" , kuznet@ms2.inr.ac.ru, nmiell@comcast.net, linux-kernel@vger.kernel.org, drepper@redhat.com, akpm@osdl.org, netdev@vger.kernel.org, zach.brown@oracle.com, hch@infradead.org Return-path: Received: from nz-out-0102.google.com ([64.233.162.203]:29790 "EHLO nz-out-0102.google.com") by vger.kernel.org with ESMTP id S1751512AbWHWJtX (ORCPT ); Wed, 23 Aug 2006 05:49:23 -0400 Received: by nz-out-0102.google.com with SMTP id n1so41428nzf for ; Wed, 23 Aug 2006 02:49:22 -0700 (PDT) To: "Evgeniy Polyakov" In-Reply-To: <20060823083859.GA8936@2ka.mipt.ru> Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 8/23/06, Evgeniy Polyakov wrote: > On Wed, Aug 23, 2006 at 10:22:06AM +0200, Jari Sundell (sundell.software@gmail.com) wrote: > > On 8/23/06, Evgeniy Polyakov wrote: > > >void * in structure exported to userspace is forbidden. > > > > Only void * I'm seeing belongs to the user, (udata) perhaps you are > > talking of something different? > > Yes, exactly about it. > > I put union { > u32 a[2]; > void *b; > } > epcially to eliminate that problem. It's just random data of a known maximum size appended to the struct, I'm sure you can find a clean way to handle it. If you mangle the first variable name in your union, you'll end up with something that should be usable instead of udata. > And I'm not that sure aboit stuff like uptr_t or how they call pointers > in userspace and kernelspace. Well, I can't find any use of pointers in your struct ukevent, nor in any of the kqueue events in my man page. So if this is a deficit it applies to both, I guess? > ukevent is aligned to 8 bytes already (it's size selected to be 40 bytes), > so it should not be a problem. > > > Eric Even if it is so, wouldn't it be better to be explicit about it? Rakshasa