All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Hans J. Koch" <hjk@hansjkoch.de>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: Benedikt Spranger <b.spranger@linutronix.de>,
	linux-kernel@vger.kernel.org, hjk@hansjkoch.de,
	Alexander.Frank@eberspaecher.com
Subject: Re: [PATCH 2/2] uio: do not expose inode to uio open/release hooks
Date: Wed, 12 Dec 2012 02:42:22 +0100	[thread overview]
Message-ID: <20121212014221.GA2642@local> (raw)
In-Reply-To: <20121211232032.GA24933@kroah.com>

On Tue, Dec 11, 2012 at 03:20:32PM -0800, Greg KH wrote:
> On Wed, Dec 12, 2012 at 12:12:02AM +0100, Benedikt Spranger wrote:
> > The inode parameter is unused by in kernel users of UIO.
> 
> Ok.
> 
> > Also the inode parameter makes it hard to resolve the existing open(),
> > mmap() and close() difficulty.
> 
> I don't understand, what do you mean by this?  What is this parameter
> causing problems with?

The problem is that according to POSIX, it is guaranteed that in userspace
you can do

fd = open("/dev/uio0", ...)
ptr = mmap(...fd...)
close(fd)

with ptr still being valid and useable after that.

Thanks,
Hans

  reply	other threads:[~2012-12-12  1:42 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-12-11 23:12 [PATCH 0/2] uio: open(), mmap(), close() Benedikt Spranger
2012-12-11 23:12 ` [PATCH 1/2] uio: add warning to documentation Benedikt Spranger
2012-12-11 23:18   ` Greg KH
2012-12-12  0:45     ` Benedikt Spranger
2012-12-12  4:49       ` Greg KH
2012-12-12  1:56     ` Hans J. Koch
2012-12-12  4:47       ` Greg KH
2012-12-11 23:12 ` [PATCH 2/2] uio: do not expose inode to uio open/release hooks Benedikt Spranger
2012-12-11 23:20   ` Greg KH
2012-12-12  1:42     ` Hans J. Koch [this message]
2012-12-12  4:46       ` Greg KH
2012-12-12  8:50         ` Hans J. Koch
2012-12-12  8:56           ` Benedikt Spranger
2012-12-12 15:08             ` Greg KH
2012-12-13  0:08               ` Hans J. Koch
2012-12-13  0:15                 ` Greg KH

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20121212014221.GA2642@local \
    --to=hjk@hansjkoch.de \
    --cc=Alexander.Frank@eberspaecher.com \
    --cc=b.spranger@linutronix.de \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.