From patchwork Tue May 7 10:33:19 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 242141 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 80D962C0113 for ; Tue, 7 May 2013 20:34:30 +1000 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UZfE0-0007PA-9Y; Tue, 07 May 2013 10:34:24 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UZfCy-0006ly-Vg for kernel-team@lists.ubuntu.com; Tue, 07 May 2013 10:33:20 +0000 Received: from bl16-161-151.dsl.telepac.pt ([188.81.161.151] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1UZfCy-0008Q7-Jz; Tue, 07 May 2013 10:33:20 +0000 From: Luis Henriques To: Federico Vaga Subject: [ 3.5.y.z extended stable ] Patch "serial_core.c: add put_device() after device_find_child()" has been added to staging queue Date: Tue, 7 May 2013 11:33:19 +0100 Message-Id: <1367922799-24449-1-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 X-Extended-Stable: 3.5 Cc: Greg Kroah-Hartman , kernel-team@lists.ubuntu.com X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com This is a note to let you know that I have just added a patch titled serial_core.c: add put_device() after device_find_child() to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 2cbe34ff5f1d2671da47d5fa4e6e13a503c4f56e Mon Sep 17 00:00:00 2001 From: Federico Vaga Date: Mon, 15 Apr 2013 16:01:07 +0200 Subject: [PATCH] serial_core.c: add put_device() after device_find_child() commit 5a65dcc04cda41f4122aacc37a5a348454645399 upstream. The serial core uses device_find_child() but does not drop the reference to the retrieved child after using it. This patch add the missing put_device(). What I have done to test this issue. I used a machine with an AMBA PL011 serial driver. I tested the patch on next-20120408 because the last branch [next-20120415] does not boot on this board. For test purpose, I added some pr_info() messages to print the refcount after device_find_child() (lines: 1937,2009), and after put_device() (lines: 1947, 2021). Boot the machine *without* put_device(). Then: echo reboot > /sys/power/disk echo disk > /sys/power/state [ 87.058575] uart_suspend_port:1937 refcount 4 [ 87.058582] uart_suspend_port:1947 refcount 4 [ 87.098083] uart_resume_port:2009refcount 5 [ 87.098088] uart_resume_port:2021 refcount 5 echo disk > /sys/power/state [ 103.055574] uart_suspend_port:1937 refcount 6 [ 103.055580] uart_suspend_port:1947 refcount 6 [ 103.095322] uart_resume_port:2009 refcount 7 [ 103.095327] uart_resume_port:2021 refcount 7 echo disk > /sys/power/state [ 252.459580] uart_suspend_port:1937 refcount 8 [ 252.459586] uart_suspend_port:1947 refcount 8 [ 252.499611] uart_resume_port:2009 refcount 9 [ 252.499616] uart_resume_port:2021 refcount 9 The refcount continuously increased. Boot the machine *with* this patch. Then: echo reboot > /sys/power/disk echo disk > /sys/power/state [ 159.333559] uart_suspend_port:1937 refcount 4 [ 159.333566] uart_suspend_port:1947 refcount 3 [ 159.372751] uart_resume_port:2009 refcount 4 [ 159.372755] uart_resume_port:2021 refcount 3 echo disk > /sys/power/state [ 185.713614] uart_suspend_port:1937 refcount 4 [ 185.713621] uart_suspend_port:1947 refcount 3 [ 185.752935] uart_resume_port:2009 refcount 4 [ 185.752940] uart_resume_port:2021 refcount 3 echo disk > /sys/power/state [ 207.458584] uart_suspend_port:1937 refcount 4 [ 207.458591] uart_suspend_port:1947 refcount 3 [ 207.498598] uart_resume_port:2009 refcount 4 [ 207.498605] uart_resume_port:2021 refcount 3 The refcount correctly handled. Signed-off-by: Federico Vaga Signed-off-by: Greg Kroah-Hartman Signed-off-by: Luis Henriques --- drivers/tty/serial/serial_core.c | 4 ++++ 1 file changed, 4 insertions(+) -- 1.8.1.2 diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 246b823..4185cc5 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -1877,6 +1877,8 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport) mutex_unlock(&port->mutex); return 0; } + put_device(tty_dev); + if (console_suspend_enabled || !uart_console(uport)) uport->suspended = 1; @@ -1942,9 +1944,11 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) disable_irq_wake(uport->irq); uport->irq_wake = 0; } + put_device(tty_dev); mutex_unlock(&port->mutex); return 0; } + put_device(tty_dev); uport->suspended = 0; /*