From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753918Ab2I0R6f (ORCPT ); Thu, 27 Sep 2012 13:58:35 -0400 Received: from mail-bk0-f46.google.com ([209.85.214.46]:52566 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753123Ab2I0R6e (ORCPT ); Thu, 27 Sep 2012 13:58:34 -0400 Date: Thu, 27 Sep 2012 21:58:30 +0400 From: Cyrill Gorcunov To: Jiri Slaby Cc: linux-kernel@vger.kernel.org, alan@lxorguk.ukuu.org.uk, hpa@zytor.com, gregkh@linuxfoundation.org, xemul@parallels.com Subject: Re: [patch 2/2] tty: Add get- ioctls to fetch tty status v2 Message-ID: <20120927175830.GT6618@moon> References: <20120927165958.287690622@openvz.org> <20120927170137.805935065@openvz.org> <506491C1.7060807@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <506491C1.7060807@suse.cz> 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 On Thu, Sep 27, 2012 at 07:49:53PM +0200, Jiri Slaby wrote: > On 09/27/2012 07:00 PM, Cyrill Gorcunov wrote: > > @@ -199,6 +207,25 @@ static int pty_set_pktmode(struct tty_st > > return 0; > > } > > > > +/* Get the packet mode of a pty */ > > +static int pty_get_pktmode(struct tty_struct *tty, int __user *arg) > > +{ > > + unsigned long flags; > > + int pktmode; > > + > > + if (tty->driver->subtype != PTY_TYPE_MASTER) > > + return -ENOTTY; > > The same as for 1/2^UFixed in v3 ;). Already sent update, thanks :-) > > > + spin_lock_irqsave(&tty->ctrl_lock, flags); > > I believe the lock is not the right one. It protects ctrl_status in > TIOCPKT, not the packet. And it very seems that packet is unprotected at > all over the code => the lock does not improve anything and is redundant. Indeed, thanks Jiri! > > > + pktmode = tty->packet; > > + spin_unlock_irqrestore(&tty->ctrl_lock, flags); > > + > > + if (put_user(pktmode, arg)) > > + return -EFAULT; > > + > > + return 0; > > This can be just > return put_user(pktmode, arg); > Right? As far as I see, yeah, put_user_[n] does return -efault as well. > > > +} > > + > ... > > --- tty.git.orig/include/asm-generic/ioctls.h > > +++ tty.git/include/asm-generic/ioctls.h > > @@ -74,6 +74,9 @@ > > #define TCSETXW 0x5435 > > #define TIOCSIG _IOW('T', 0x36, int) /* pty: generate signal */ > > #define TIOCVHANGUP 0x5437 > > +#define TIOCGPKT _IOR('T', 0x38, int) /* Get packet mode state */ > > +#define TIOCGPTLCK _IOR('T', 0x39, int) /* Get Pty lock state */ > > +#define TIOCGEXCL _IOR('T', 0x40, int) /* Get exclusive mode state */ > > This is not enough. Some arches do not include this file in their > ioctls.h. You need to update them all. Crap, for some reason cscope has not indexed them but git grep helped. I'll update. Thanks, Jiri! Cyrill