To: Albert Cahalan <albert@users.sf.net>
Cc: linux-kernel mailing list <linux-kernel@vger.kernel.org>,
       arjanv@redhat.com, viro@parcelfarce.linux.theplanet.co.uk,
       mst@mellanox.co.il, filia@softhome.net
Subject: Re: f_ops flag to speed up compatible ioctls in linux kernel
References: <1094052981.431.7160.camel@cube>
From: Roland Dreier <roland@topspin.com>
Date: Wed, 01 Sep 2004 08:59:09 -0700
In-Reply-To: <1094052981.431.7160.camel@cube> (Albert Cahalan's message of
 "01 Sep 2004 11:36:21 -0400")
Message-ID: <52vfey0ylu.fsf@topspin.com>
User-Agent: Gnus/5.1006 (Gnus v5.10.6) XEmacs/21.4 (Security Through
 Obscurity, linux)
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 894
Lines: 20

    Albert> Per-command parameters included?

    Albert> People really do want private syscalls. An ioctl is that,
    Albert> in a namespace defined by the file descriptor. So ioctl()
    Albert> provides local scope to something that would otherwise be
    Albert> global.

Yes, this is exactly right.  One issue raised by this thread is that
the ioctl32 compatibility code only allows one compatibility handler
per ioctl number.  It seems that this creates all sorts of
possibilities for mayhem because it makes the ioctl namespace global
in scope in some situations.  Does anyone have any thoughts on if/how
this should be addressed.

 - Roland
-
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/