From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Kent Subject: Re: [PATCH] autofs4 - fix comms packet struct size Date: Mon, 20 Feb 2006 09:05:59 +0800 (WST) Message-ID: References: <20060219141517.GA7942@infradead.org> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Andrew Morton , Kernel Mailing List , linux-fsdevel , autofs mailing list Return-path: Received: from wombat.indigo.net.au ([202.0.185.19]:32271 "EHLO wombat.indigo.net.au") by vger.kernel.org with ESMTP id S932491AbWBTBGp (ORCPT ); Sun, 19 Feb 2006 20:06:45 -0500 To: Christoph Hellwig In-Reply-To: <20060219141517.GA7942@infradead.org> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Sun, 19 Feb 2006, Christoph Hellwig wrote: > On Sun, Feb 19, 2006 at 10:11:31PM +0800, Ian Kent wrote: > > > > Set userspace communication struct fields to fixed size. > > > > Signed-off-by: Ian Kent > > > > --- linux-2.6.16-rc3-mm1/include/linux/auto_fs4.h.fix-v5-packet-size 2006-02-17 19:15:49.000000000 +0800 > > +++ linux-2.6.16-rc3-mm1/include/linux/auto_fs4.h 2006-02-17 19:12:09.000000000 +0800 > > @@ -65,10 +65,10 @@ struct autofs_v5_packet { > > autofs_wqt_t wait_queue_token; > > Hiding types in user visible structures behind typedefs is bad. > What type is behind this? If this is not an __u32 you have > a padding issue. This has been an occassion problem for a long time. Since it dates back to way before version 4 I have always been reluctant to change it. I'd rather leave it as is unless you really can't accept it. > > > __u32 dev; > > __u64 ino; > > - uid_t uid; > > - gid_t gid; > > - pid_t pid; > > - pid_t tgid; > > + __u64 uid; > > + __u64 gid; > > + __u64 pid; > > + __u64 tgid; > > These should be 32bit values. OK. But will they be 32 bit for the life of this struct? Once userspace programs are using this it can't ever change. > > > int len; > > this should become a fixed-size type aswell. OK. That shouldn't cause a problem. I'll change that also. > > > char name[NAME_MAX+1]; > > }; > > --- linux-2.6.16-rc3-mm1/fs/autofs4/autofs_i.h.fix-v5-packet-size 2006-02-17 19:17:03.000000000 +0800 > > +++ linux-2.6.16-rc3-mm1/fs/autofs4/autofs_i.h 2006-02-17 19:17:25.000000000 +0800 > > @@ -79,10 +79,10 @@ struct autofs_wait_queue { > > char *name; > > u32 dev; > > u64 ino; > > - uid_t uid; > > - gid_t gid; > > - pid_t pid; > > - pid_t tgid; > > + u64 uid; > > + u64 gid; > > + u64 pid; > > + u64 tgid; > > /* This is for status reporting upon return */ > > int status; > > atomic_t notified; > > This is an in-kernel structure, isn't it? No need to use u64 here. Yes, I was thinking the same thing when I did it. I'll fix that. Thanks Christoph. Ian