linux-kernel - [PATCH 3/3] ipoctal: get carrier driver to avoid rmmod

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1409671901-4009-4-git-send-email-federico.vaga@cern.ch>
Date:	Tue, 2 Sep 2014 17:31:41 +0200
From:	Federico Vaga <federico.vaga@...n.ch>
To:	Samuel Iglesias Gonsalvez <siglesias@...lia.com>,
	Jens Taprogge <jens.taprogge@...rogge.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
CC:	<industrypack-devel@...ts.sourceforge.net>,
	<linux-kernel@...r.kernel.org>,
	Federico Vaga <federico.vaga@...n.ch>
Subject: [PATCH 3/3] ipoctal: get carrier driver to avoid rmmod

Signed-off-by: Federico Vaga <federico.vaga@...n.ch>
---
 drivers/ipack/devices/ipoctal.c |   30 +++++++++++++++++++++++++++---
 1 file changed, 27 insertions(+), 3 deletions(-)

diff --git a/drivers/ipack/devices/ipoctal.c b/drivers/ipack/devices/ipoctal.c
index e531379..035d544 100644
--- a/drivers/ipack/devices/ipoctal.c
+++ b/drivers/ipack/devices/ipoctal.c
@@ -55,6 +55,12 @@ struct ipoctal {
 	u8 __iomem			*int_space;
 };
 
+static inline struct ipoctal *chan_to_ipoctal(struct ipoctal_channel *chan,
+					      unsigned int index)
+{
+	return container_of(chan, struct ipoctal, channel[index]);
+}
+
 static void ipoctal_reset_channel(struct ipoctal_channel *channel)
 {
 	iowrite8(CR_DISABLE_RX | CR_DISABLE_TX, &channel->regs->w.cr);
@@ -82,12 +88,20 @@ static int ipoctal_port_activate(struct tty_port *port, struct tty_struct *tty)
 
 static int ipoctal_open(struct tty_struct *tty, struct file *file)
 {
-	struct ipoctal_channel *channel;
+	struct ipoctal_channel *channel = dev_get_drvdata(tty->dev);
+	struct ipoctal *ipoctal = chan_to_ipoctal(channel, tty->index);
+	int err;
 
-	channel = dev_get_drvdata(tty->dev);
 	tty->driver_data = channel;
 
-	return tty_port_open(&channel->tty_port, tty, file);
+	if (!ipack_get_carrier(ipoctal->dev))
+		return -EBUSY;
+
+	err = tty_port_open(&channel->tty_port, tty, file);
+	if (err)
+		ipack_put_carrier(ipoctal->dev);
+
+	return err;
 }
 
 static void ipoctal_reset_stats(struct ipoctal_stats *stats)
@@ -631,6 +645,15 @@ static void ipoctal_shutdown(struct tty_struct *tty)
 	clear_bit(ASYNCB_INITIALIZED, &channel->tty_port.flags);
 }
 
+static void ipoctal_cleanup(struct tty_struct *tty)
+{
+	struct ipoctal_channel *channel = tty->driver_data;
+	struct ipoctal *ipoctal = chan_to_ipoctal(channel, tty->index);
+
+	/* release the carrier driver */
+	ipack_put_carrier(ipoctal->dev);
+}
+
 static const struct tty_operations ipoctal_fops = {
 	.ioctl =		NULL,
 	.open =			ipoctal_open,
@@ -642,6 +665,7 @@ static const struct tty_operations ipoctal_fops = {
 	.get_icount =		ipoctal_get_icount,
 	.hangup =		ipoctal_hangup,
 	.shutdown =		ipoctal_shutdown,
+	.cleanup =              ipoctal_cleanup,
 };
 
 static int ipoctal_probe(struct ipack_device *dev)
-- 
1.7.10.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/