From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Peter Hurley <peter@hurleysoftware.com>
Cc: Marcel Holtmann <marcel@holtmann.org>,
Gustavo Padovan <gustavo@padovan.org>,
Johan Hedberg <johan.hedberg@gmail.com>,
Gianluca Anzolin <gianluca@sottospazio.it>,
Alexander Holler <holler@ahsoftware.de>,
Andrey Vihrov <andrey.vihrov@gmail.com>,
Sander Eikelenboom <linux@eikelenboom.it>,
linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org,
Jiri Slaby <jslaby@suse.cz>
Subject: Re: [PATCH 04/24] tty: Fix ref counting for port krefs
Date: Thu, 13 Feb 2014 10:36:16 -0800 [thread overview]
Message-ID: <20140213183616.GA13509@kroah.com> (raw)
In-Reply-To: <1391997564-1805-5-git-send-email-peter@hurleysoftware.com>
On Sun, Feb 09, 2014 at 08:59:04PM -0500, Peter Hurley wrote:
> The tty core supports two models for handling tty_port lifetimes;
> the tty_port can use the kref supplied by tty_port (which will
> automatically destruct the tty_port when the ref count drops to
> zero) or it can destruct the tty_port manually.
>
> For tty drivers that choose to use the port kref to manage the
> tty_port lifetime, it is not possible to safely acquire a port
> reference conditionally. If the last reference is released after
> evaluating the condition but before acquiring the reference, a
> bogus reference will be held while the tty_port destruction
> commences.
>
> Rather, only acquire a port reference if the ref count is non-zero
> and allow the caller to distinguish if a reference has successfully
> been acquired.
>
> Cc: Jiri Slaby <jslaby@suse.cz>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
next prev parent reply other threads:[~2014-02-13 18:35 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-10 1:59 [PATCH 00/24] rfcomm fixes Peter Hurley
2014-02-10 1:59 ` [PATCH 01/24] Revert "Bluetooth: Remove rfcomm_carrier_raised()" Peter Hurley
2014-02-10 1:59 ` [PATCH 02/24] Revert "Bluetooth: Always wait for a connection on RFCOMM open()" Peter Hurley
2014-02-10 1:59 ` [PATCH 03/24] Revert "Bluetooth: Move rfcomm_get_device() before rfcomm_dev_activate()" Peter Hurley
2014-02-10 1:59 ` [PATCH 04/24] tty: Fix ref counting for port krefs Peter Hurley
2014-02-13 18:36 ` Greg Kroah-Hartman [this message]
2014-02-10 1:59 ` [PATCH 05/24] Bluetooth: Fix racy acquire of rfcomm_dev reference Peter Hurley
2014-02-10 1:59 ` [PATCH 06/24] Bluetooth: Exclude released devices from RFCOMMGETDEVLIST ioctl Peter Hurley
2014-02-10 1:59 ` [PATCH 07/24] Bluetooth: Release rfcomm_dev only once Peter Hurley
2014-02-10 1:59 ` [PATCH 08/24] Bluetooth: Fix unreleased rfcomm_dev reference Peter Hurley
2014-02-10 1:59 ` [PATCH 09/24] Bluetooth: Fix RFCOMM tty teardown race Peter Hurley
2014-02-10 1:59 ` [PATCH 10/24] Bluetooth: Verify dlci not in use before rfcomm_dev create Peter Hurley
2014-02-10 1:59 ` [PATCH 11/24] Bluetooth: Simplify RFCOMM session state eval Peter Hurley
2014-02-10 1:59 ` [PATCH 12/24] Bluetooth: Refactor deferred setup test in rfcomm_dlc_close() Peter Hurley
2014-02-10 1:59 ` [PATCH 13/24] Bluetooth: Refactor dlc disconnect logic " Peter Hurley
2014-02-10 1:59 ` [PATCH 14/24] Bluetooth: Directly close dlc for not yet started RFCOMM session Peter Hurley
2014-02-10 1:59 ` [PATCH 15/24] Bluetooth: Fix unsafe RFCOMM device parenting Peter Hurley
2014-02-10 1:59 ` [PATCH 16/24] Bluetooth: Fix RFCOMM parent device for reused dlc Peter Hurley
2014-02-10 1:59 ` [PATCH 17/24] Bluetooth: Rename __rfcomm_dev_get() to __rfcomm_dev_lookup() Peter Hurley
2014-02-10 1:59 ` [PATCH 18/24] Bluetooth: Serialize RFCOMMCREATEDEV and RFCOMMRELEASEDEV ioctls Peter Hurley
2014-02-10 1:59 ` [PATCH 19/24] Bluetooth: Refactor rfcomm_dev_add() Peter Hurley
2014-02-10 1:59 ` [PATCH 20/24] Bluetooth: Cleanup RFCOMM device registration error handling Peter Hurley
2014-02-10 1:59 ` [PATCH 21/24] Bluetooth: Force -EIO from tty read/write if .activate() fails Peter Hurley
2014-02-10 1:59 ` [PATCH 22/24] Bluetooth: Don't fail RFCOMM tty writes Peter Hurley
2014-02-10 1:59 ` [PATCH 23/24] Bluetooth: Refactor write_room() calculation Peter Hurley
2014-02-10 1:59 ` [PATCH 24/24] Bluetooth: Fix " Peter Hurley
2014-02-10 22:09 ` [PATCH 00/24] rfcomm fixes Marcel Holtmann
2014-02-10 23:00 ` Peter Hurley
2014-02-12 22:58 ` Marcel Holtmann
2014-02-13 0:38 ` Peter Hurley
2014-02-13 21:48 ` Alexander Holler
2014-02-12 11:06 ` Sander Eikelenboom
2014-03-03 19:38 ` Sander Eikelenboom
2014-03-10 8:38 ` [RC6 Bell Chime] " Sander Eikelenboom
2014-03-10 15:08 ` John W. Linville
2014-03-11 15:14 ` [RC6 Bell Chime] " Marcel Holtmann
2014-03-14 0:49 ` Sander Eikelenboom
2014-03-14 1:28 ` Marcel Holtmann
2014-03-14 1:29 ` Peter Hurley
2014-03-15 13:51 ` Sander Eikelenboom
2014-03-15 17:53 ` Linus Torvalds
2014-03-15 20:45 ` Peter Hurley
2014-03-15 22:20 ` Sander Eikelenboom
2014-03-16 0:16 ` Linus Torvalds
2014-02-13 21:41 ` Alexander Holler
2014-02-14 21:45 ` Marcel Holtmann
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