diff mbox series

[1/2] rpmsg: Fix calling device_lock() on non-initialized device

Message ID 20220429195946.1061725-2-krzysztof.kozlowski@linaro.org (mailing list archive)
State New
Headers show
Series rpmsg: fix after driver_override patchset | expand

Commit Message

Krzysztof Kozlowski April 29, 2022, 7:59 p.m. UTC
driver_set_override() helper uses device_lock() so it should not be
called before rpmsg_register_device() (which calls device_register()).
Effect can be seen with CONFIG_DEBUG_MUTEXES:

  DEBUG_LOCKS_WARN_ON(lock->magic != lock)
  WARNING: CPU: 3 PID: 57 at kernel/locking/mutex.c:582 __mutex_lock+0x1ec/0x430
  ...
  Call trace:
   __mutex_lock+0x1ec/0x430
   mutex_lock_nested+0x44/0x50
   driver_set_override+0x124/0x150
   qcom_glink_native_probe+0x30c/0x3b0
   glink_rpm_probe+0x274/0x350
   platform_probe+0x6c/0xe0
   really_probe+0x17c/0x3d0
   __driver_probe_device+0x114/0x190
   driver_probe_device+0x3c/0xf0
   ...

Refactor the rpmsg_register_device() function to use two-step device
registering (initialization + add) and call driver_set_override() in
proper moment.

This moves the code around, so while at it also NULL-ify the
rpdev->driver_override in error path to be sure it won't be kfree()
second time.

Fixes: 42cd402b8fd4 ("rpmsg: Fix kfree() of static memory on setting driver_override")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

---

Commit SHA from linux-next - Greg's tree.
---
 drivers/rpmsg/rpmsg_core.c     | 33 ++++++++++++++++++++++++++++++---
 drivers/rpmsg/rpmsg_internal.h | 14 +-------------
 drivers/rpmsg/rpmsg_ns.c       | 14 +-------------
 include/linux/rpmsg.h          |  8 ++++++++
 4 files changed, 40 insertions(+), 29 deletions(-)

Comments

Marek Szyprowski April 29, 2022, 9:56 p.m. UTC | #1
On 29.04.2022 21:59, Krzysztof Kozlowski wrote:
> driver_set_override() helper uses device_lock() so it should not be
> called before rpmsg_register_device() (which calls device_register()).
> Effect can be seen with CONFIG_DEBUG_MUTEXES:
>
>    DEBUG_LOCKS_WARN_ON(lock->magic != lock)
>    WARNING: CPU: 3 PID: 57 at kernel/locking/mutex.c:582 __mutex_lock+0x1ec/0x430
>    ...
>    Call trace:
>     __mutex_lock+0x1ec/0x430
>     mutex_lock_nested+0x44/0x50
>     driver_set_override+0x124/0x150
>     qcom_glink_native_probe+0x30c/0x3b0
>     glink_rpm_probe+0x274/0x350
>     platform_probe+0x6c/0xe0
>     really_probe+0x17c/0x3d0
>     __driver_probe_device+0x114/0x190
>     driver_probe_device+0x3c/0xf0
>     ...
>
> Refactor the rpmsg_register_device() function to use two-step device
> registering (initialization + add) and call driver_set_override() in
> proper moment.
>
> This moves the code around, so while at it also NULL-ify the
> rpdev->driver_override in error path to be sure it won't be kfree()
> second time.
>
> Fixes: 42cd402b8fd4 ("rpmsg: Fix kfree() of static memory on setting driver_override")
> Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
>
> Commit SHA from linux-next - Greg's tree.
> ---
>   drivers/rpmsg/rpmsg_core.c     | 33 ++++++++++++++++++++++++++++++---
>   drivers/rpmsg/rpmsg_internal.h | 14 +-------------
>   drivers/rpmsg/rpmsg_ns.c       | 14 +-------------
>   include/linux/rpmsg.h          |  8 ++++++++
>   4 files changed, 40 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
> index 95fc283f6af7..4938fc4eff00 100644
> --- a/drivers/rpmsg/rpmsg_core.c
> +++ b/drivers/rpmsg/rpmsg_core.c
> @@ -593,24 +593,51 @@ static struct bus_type rpmsg_bus = {
>   	.remove		= rpmsg_dev_remove,
>   };
>   
> -int rpmsg_register_device(struct rpmsg_device *rpdev)
> +/*
> + * A helper for registering rpmsg device with driver override and name.
> + * Drivers should not be using it, but instead rpmsg_register_device().
> + */
> +int rpmsg_register_device_override(struct rpmsg_device *rpdev,
> +				   const char *driver_override)
>   {
>   	struct device *dev = &rpdev->dev;
>   	int ret;
>   
> +	if (driver_override)
> +		strcpy(rpdev->id.name, driver_override);
> +
>   	dev_set_name(&rpdev->dev, "%s.%s.%d.%d", dev_name(dev->parent),
>   		     rpdev->id.name, rpdev->src, rpdev->dst);
>   
>   	rpdev->dev.bus = &rpmsg_bus;
>   
> -	ret = device_register(&rpdev->dev);
> +	device_initialize(dev);
> +	if (driver_override) {
> +		ret = driver_set_override(dev, &rpdev->driver_override,
> +					  driver_override,
> +					  strlen(driver_override));
> +		if (ret) {
> +			dev_err(dev, "device_set_override failed: %d\n", ret);
> +			return ret;
> +		}
> +	}
> +
> +	ret = device_add(dev);
>   	if (ret) {
> -		dev_err(dev, "device_register failed: %d\n", ret);
> +		dev_err(dev, "device_add failed: %d\n", ret);
> +		kfree(rpdev->driver_override);
> +		rpdev->driver_override = NULL;
>   		put_device(&rpdev->dev);
>   	}
>   
>   	return ret;
>   }
> +EXPORT_SYMBOL(rpmsg_register_device_override);
> +
> +int rpmsg_register_device(struct rpmsg_device *rpdev)
> +{
> +	return rpmsg_register_device_override(rpdev, NULL);
> +}
>   EXPORT_SYMBOL(rpmsg_register_device);
>   
>   /*
> diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h
> index 3e81642238d2..a22cd4abe7d1 100644
> --- a/drivers/rpmsg/rpmsg_internal.h
> +++ b/drivers/rpmsg/rpmsg_internal.h
> @@ -94,19 +94,7 @@ int rpmsg_release_channel(struct rpmsg_device *rpdev,
>    */
>   static inline int rpmsg_ctrldev_register_device(struct rpmsg_device *rpdev)
>   {
> -	int ret;
> -
> -	strcpy(rpdev->id.name, "rpmsg_ctrl");
> -	ret = driver_set_override(&rpdev->dev, &rpdev->driver_override,
> -				  rpdev->id.name, strlen(rpdev->id.name));
> -	if (ret)
> -		return ret;
> -
> -	ret = rpmsg_register_device(rpdev);
> -	if (ret)
> -		kfree(rpdev->driver_override);
> -
> -	return ret;
> +	return rpmsg_register_device_override(rpdev, "rpmsg_ctrl");
>   }
>   
>   #endif
> diff --git a/drivers/rpmsg/rpmsg_ns.c b/drivers/rpmsg/rpmsg_ns.c
> index 8eb8f328237e..c70ad03ff2e9 100644
> --- a/drivers/rpmsg/rpmsg_ns.c
> +++ b/drivers/rpmsg/rpmsg_ns.c
> @@ -20,22 +20,10 @@
>    */
>   int rpmsg_ns_register_device(struct rpmsg_device *rpdev)
>   {
> -	int ret;
> -
> -	strcpy(rpdev->id.name, "rpmsg_ns");
> -	ret = driver_set_override(&rpdev->dev, &rpdev->driver_override,
> -				  rpdev->id.name, strlen(rpdev->id.name));
> -	if (ret)
> -		return ret;
> -
>   	rpdev->src = RPMSG_NS_ADDR;
>   	rpdev->dst = RPMSG_NS_ADDR;
>   
> -	ret = rpmsg_register_device(rpdev);
> -	if (ret)
> -		kfree(rpdev->driver_override);
> -
> -	return ret;
> +	return rpmsg_register_device_override(rpdev, "rpmsg_ns");
>   }
>   EXPORT_SYMBOL(rpmsg_ns_register_device);
>   
> diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h
> index 20c8cd1cde21..523c98b96cb4 100644
> --- a/include/linux/rpmsg.h
> +++ b/include/linux/rpmsg.h
> @@ -165,6 +165,8 @@ static inline __rpmsg64 cpu_to_rpmsg64(struct rpmsg_device *rpdev, u64 val)
>   
>   #if IS_ENABLED(CONFIG_RPMSG)
>   
> +int rpmsg_register_device_override(struct rpmsg_device *rpdev,
> +				   const char *driver_override);
>   int rpmsg_register_device(struct rpmsg_device *rpdev);
>   int rpmsg_unregister_device(struct device *parent,
>   			    struct rpmsg_channel_info *chinfo);
> @@ -192,6 +194,12 @@ ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept);
>   
>   #else
>   
> +static inline int rpmsg_register_device_override(struct rpmsg_device *rpdev,
> +						 const char *driver_override)
> +{
> +	return -ENXIO;
> +}
> +
>   static inline int rpmsg_register_device(struct rpmsg_device *rpdev)
>   {
>   	return -ENXIO;

Best regards
diff mbox series

Patch

diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
index 95fc283f6af7..4938fc4eff00 100644
--- a/drivers/rpmsg/rpmsg_core.c
+++ b/drivers/rpmsg/rpmsg_core.c
@@ -593,24 +593,51 @@  static struct bus_type rpmsg_bus = {
 	.remove		= rpmsg_dev_remove,
 };
 
-int rpmsg_register_device(struct rpmsg_device *rpdev)
+/*
+ * A helper for registering rpmsg device with driver override and name.
+ * Drivers should not be using it, but instead rpmsg_register_device().
+ */
+int rpmsg_register_device_override(struct rpmsg_device *rpdev,
+				   const char *driver_override)
 {
 	struct device *dev = &rpdev->dev;
 	int ret;
 
+	if (driver_override)
+		strcpy(rpdev->id.name, driver_override);
+
 	dev_set_name(&rpdev->dev, "%s.%s.%d.%d", dev_name(dev->parent),
 		     rpdev->id.name, rpdev->src, rpdev->dst);
 
 	rpdev->dev.bus = &rpmsg_bus;
 
-	ret = device_register(&rpdev->dev);
+	device_initialize(dev);
+	if (driver_override) {
+		ret = driver_set_override(dev, &rpdev->driver_override,
+					  driver_override,
+					  strlen(driver_override));
+		if (ret) {
+			dev_err(dev, "device_set_override failed: %d\n", ret);
+			return ret;
+		}
+	}
+
+	ret = device_add(dev);
 	if (ret) {
-		dev_err(dev, "device_register failed: %d\n", ret);
+		dev_err(dev, "device_add failed: %d\n", ret);
+		kfree(rpdev->driver_override);
+		rpdev->driver_override = NULL;
 		put_device(&rpdev->dev);
 	}
 
 	return ret;
 }
+EXPORT_SYMBOL(rpmsg_register_device_override);
+
+int rpmsg_register_device(struct rpmsg_device *rpdev)
+{
+	return rpmsg_register_device_override(rpdev, NULL);
+}
 EXPORT_SYMBOL(rpmsg_register_device);
 
 /*
diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h
index 3e81642238d2..a22cd4abe7d1 100644
--- a/drivers/rpmsg/rpmsg_internal.h
+++ b/drivers/rpmsg/rpmsg_internal.h
@@ -94,19 +94,7 @@  int rpmsg_release_channel(struct rpmsg_device *rpdev,
  */
 static inline int rpmsg_ctrldev_register_device(struct rpmsg_device *rpdev)
 {
-	int ret;
-
-	strcpy(rpdev->id.name, "rpmsg_ctrl");
-	ret = driver_set_override(&rpdev->dev, &rpdev->driver_override,
-				  rpdev->id.name, strlen(rpdev->id.name));
-	if (ret)
-		return ret;
-
-	ret = rpmsg_register_device(rpdev);
-	if (ret)
-		kfree(rpdev->driver_override);
-
-	return ret;
+	return rpmsg_register_device_override(rpdev, "rpmsg_ctrl");
 }
 
 #endif
diff --git a/drivers/rpmsg/rpmsg_ns.c b/drivers/rpmsg/rpmsg_ns.c
index 8eb8f328237e..c70ad03ff2e9 100644
--- a/drivers/rpmsg/rpmsg_ns.c
+++ b/drivers/rpmsg/rpmsg_ns.c
@@ -20,22 +20,10 @@ 
  */
 int rpmsg_ns_register_device(struct rpmsg_device *rpdev)
 {
-	int ret;
-
-	strcpy(rpdev->id.name, "rpmsg_ns");
-	ret = driver_set_override(&rpdev->dev, &rpdev->driver_override,
-				  rpdev->id.name, strlen(rpdev->id.name));
-	if (ret)
-		return ret;
-
 	rpdev->src = RPMSG_NS_ADDR;
 	rpdev->dst = RPMSG_NS_ADDR;
 
-	ret = rpmsg_register_device(rpdev);
-	if (ret)
-		kfree(rpdev->driver_override);
-
-	return ret;
+	return rpmsg_register_device_override(rpdev, "rpmsg_ns");
 }
 EXPORT_SYMBOL(rpmsg_ns_register_device);
 
diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h
index 20c8cd1cde21..523c98b96cb4 100644
--- a/include/linux/rpmsg.h
+++ b/include/linux/rpmsg.h
@@ -165,6 +165,8 @@  static inline __rpmsg64 cpu_to_rpmsg64(struct rpmsg_device *rpdev, u64 val)
 
 #if IS_ENABLED(CONFIG_RPMSG)
 
+int rpmsg_register_device_override(struct rpmsg_device *rpdev,
+				   const char *driver_override);
 int rpmsg_register_device(struct rpmsg_device *rpdev);
 int rpmsg_unregister_device(struct device *parent,
 			    struct rpmsg_channel_info *chinfo);
@@ -192,6 +194,12 @@  ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept);
 
 #else
 
+static inline int rpmsg_register_device_override(struct rpmsg_device *rpdev,
+						 const char *driver_override)
+{
+	return -ENXIO;
+}
+
 static inline int rpmsg_register_device(struct rpmsg_device *rpdev)
 {
 	return -ENXIO;