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From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
To: Hans de Goede <hdegoede@redhat.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andy Shevchenko <andy@infradead.org>,
	Darren Hart <dvhart@infradead.org>,
	platform-driver-x86@vger.kernel.org, linux-usb@vger.kernel.org,
	stable@vger.kernel.org
Subject: [PATCH v3 01/10] usb: typec: Take care of driver module reference counting
Date: Tue,  4 Sep 2018 14:22:10 +0300	[thread overview]
Message-ID: <20180904112219.89287-2-heikki.krogerus@linux.intel.com> (raw)
In-Reply-To: <20180904112219.89287-1-heikki.krogerus@linux.intel.com>

Functions typec_mux_get() and typec_switch_get() already
make sure that the mux device reference count is
incremented, but the same must be done to the driver module
as well to prevent the drivers from being unloaded in the
middle of operation.

This fixes a potential "BUG: unable to handle kernel paging
request at ..." from happening.

Fixes: 93dd2112c7b2 ("usb: typec: mux: Get the mux identifier from function parameter")
Cc: <stable@vger.kernel.org>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
---
 drivers/usb/typec/mux.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/typec/mux.c b/drivers/usb/typec/mux.c
index ddaac63ecf12..d990aa510fab 100644
--- a/drivers/usb/typec/mux.c
+++ b/drivers/usb/typec/mux.c
@@ -9,6 +9,7 @@
 
 #include <linux/device.h>
 #include <linux/list.h>
+#include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/usb/typec_mux.h>
 
@@ -49,8 +50,10 @@ struct typec_switch *typec_switch_get(struct device *dev)
 	mutex_lock(&switch_lock);
 	sw = device_connection_find_match(dev, "typec-switch", NULL,
 					  typec_switch_match);
-	if (!IS_ERR_OR_NULL(sw))
+	if (!IS_ERR_OR_NULL(sw)) {
+		WARN_ON(!try_module_get(sw->dev->driver->owner));
 		get_device(sw->dev);
+	}
 	mutex_unlock(&switch_lock);
 
 	return sw;
@@ -65,8 +68,10 @@ EXPORT_SYMBOL_GPL(typec_switch_get);
  */
 void typec_switch_put(struct typec_switch *sw)
 {
-	if (!IS_ERR_OR_NULL(sw))
+	if (!IS_ERR_OR_NULL(sw)) {
+		module_put(sw->dev->driver->owner);
 		put_device(sw->dev);
+	}
 }
 EXPORT_SYMBOL_GPL(typec_switch_put);
 
@@ -136,8 +141,10 @@ struct typec_mux *typec_mux_get(struct device *dev, const char *name)
 
 	mutex_lock(&mux_lock);
 	mux = device_connection_find_match(dev, name, NULL, typec_mux_match);
-	if (!IS_ERR_OR_NULL(mux))
+	if (!IS_ERR_OR_NULL(mux)) {
+		WARN_ON(!try_module_get(mux->dev->driver->owner));
 		get_device(mux->dev);
+	}
 	mutex_unlock(&mux_lock);
 
 	return mux;
@@ -152,8 +159,10 @@ EXPORT_SYMBOL_GPL(typec_mux_get);
  */
 void typec_mux_put(struct typec_mux *mux)
 {
-	if (!IS_ERR_OR_NULL(mux))
+	if (!IS_ERR_OR_NULL(mux)) {
+		module_put(mux->dev->driver->owner);
 		put_device(mux->dev);
+	}
 }
 EXPORT_SYMBOL_GPL(typec_mux_put);
 
-- 
2.18.0

WARNING: multiple messages have this Message-ID (diff)
From: Heikki Krogerus <heikki.krogerus@linux.intel.com>
To: Hans de Goede <hdegoede@redhat.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andy Shevchenko <andy@infradead.org>,
	Darren Hart <dvhart@infradead.org>,
	platform-driver-x86@vger.kernel.org, linux-usb@vger.kernel.org,
	stable@vger.kernel.org
Subject: [v3,01/10] usb: typec: Take care of driver module reference counting
Date: Tue,  4 Sep 2018 14:22:10 +0300	[thread overview]
Message-ID: <20180904112219.89287-2-heikki.krogerus@linux.intel.com> (raw)

Functions typec_mux_get() and typec_switch_get() already
make sure that the mux device reference count is
incremented, but the same must be done to the driver module
as well to prevent the drivers from being unloaded in the
middle of operation.

This fixes a potential "BUG: unable to handle kernel paging
request at ..." from happening.

Fixes: 93dd2112c7b2 ("usb: typec: mux: Get the mux identifier from function parameter")
Cc: <stable@vger.kernel.org>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
---
 drivers/usb/typec/mux.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/typec/mux.c b/drivers/usb/typec/mux.c
index ddaac63ecf12..d990aa510fab 100644
--- a/drivers/usb/typec/mux.c
+++ b/drivers/usb/typec/mux.c
@@ -9,6 +9,7 @@
 
 #include <linux/device.h>
 #include <linux/list.h>
+#include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/usb/typec_mux.h>
 
@@ -49,8 +50,10 @@ struct typec_switch *typec_switch_get(struct device *dev)
 	mutex_lock(&switch_lock);
 	sw = device_connection_find_match(dev, "typec-switch", NULL,
 					  typec_switch_match);
-	if (!IS_ERR_OR_NULL(sw))
+	if (!IS_ERR_OR_NULL(sw)) {
+		WARN_ON(!try_module_get(sw->dev->driver->owner));
 		get_device(sw->dev);
+	}
 	mutex_unlock(&switch_lock);
 
 	return sw;
@@ -65,8 +68,10 @@ EXPORT_SYMBOL_GPL(typec_switch_get);
  */
 void typec_switch_put(struct typec_switch *sw)
 {
-	if (!IS_ERR_OR_NULL(sw))
+	if (!IS_ERR_OR_NULL(sw)) {
+		module_put(sw->dev->driver->owner);
 		put_device(sw->dev);
+	}
 }
 EXPORT_SYMBOL_GPL(typec_switch_put);
 
@@ -136,8 +141,10 @@ struct typec_mux *typec_mux_get(struct device *dev, const char *name)
 
 	mutex_lock(&mux_lock);
 	mux = device_connection_find_match(dev, name, NULL, typec_mux_match);
-	if (!IS_ERR_OR_NULL(mux))
+	if (!IS_ERR_OR_NULL(mux)) {
+		WARN_ON(!try_module_get(mux->dev->driver->owner));
 		get_device(mux->dev);
+	}
 	mutex_unlock(&mux_lock);
 
 	return mux;
@@ -152,8 +159,10 @@ EXPORT_SYMBOL_GPL(typec_mux_get);
  */
 void typec_mux_put(struct typec_mux *mux)
 {
-	if (!IS_ERR_OR_NULL(mux))
+	if (!IS_ERR_OR_NULL(mux)) {
+		module_put(mux->dev->driver->owner);
 		put_device(mux->dev);
+	}
 }
 EXPORT_SYMBOL_GPL(typec_mux_put);
 

       reply	other threads:[~2018-09-04 11:22 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20180904112219.89287-1-heikki.krogerus@linux.intel.com>
2018-09-04 11:22 ` Heikki Krogerus [this message]
2018-09-04 11:22   ` [v3,01/10] usb: typec: Take care of driver module reference counting Heikki Krogerus
2018-09-04 11:22 ` [PATCH v3 02/10] usb: roles: Handle driver " Heikki Krogerus
2018-09-04 11:22   ` [v3,02/10] " Heikki Krogerus
2018-09-06 20:59   ` [PATCH v3 02/10] " Hans de Goede
2018-09-06 20:59     ` [v3,02/10] " Hans de Goede
2018-09-07  9:48     ` [PATCH v3 02/10] " Heikki Krogerus
2018-09-07  9:48       ` [v3,02/10] " Heikki Krogerus

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