IOMMU Fixes for Linux v4.13-rc6

Another fix, this time in common IOMMU sysfs code
 
 	- In the conversion from the old iommu sysfs-code to the
 	  iommu_device_register interface, I missed to update the
 	  release path for the struct device associated with an IOMMU.
 	  It freed the 'struct device', which was a pointer before, but
 	  is now embedded in another struct. Freeing from the middle of
 	  allocated memory had all kinds of nasty side effects when an
 	  IOMMU was unplugged. Unfortunatly nobody unplugged and IOMMU
 	  until now, so this was not discovered earlier.  The fix is to
 	  make the 'struct device' a pointer again.
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Merge tag 'iommu-fixes-v4.13-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

Pull IOMMU fix from Joerg Roedel:
 "Another fix, this time in common IOMMU sysfs code.

  In the conversion from the old iommu sysfs-code to the
  iommu_device_register interface, I missed to update the release path
  for the struct device associated with an IOMMU. It freed the 'struct
  device', which was a pointer before, but is now embedded in another
  struct.

  Freeing from the middle of allocated memory had all kinds of nasty
  side effects when an IOMMU was unplugged. Unfortunatly nobody
  unplugged and IOMMU until now, so this was not discovered earlier. The
  fix is to make the 'struct device' a pointer again"

* tag 'iommu-fixes-v4.13-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu: Fix wrong freeing of iommu_device->dev

drivers/iommu/amd_iommu_types.h

@@ -574,7 +574,9 @@ struct amd_iommu {
 
 static inline struct amd_iommu *dev_to_amd_iommu(struct device *dev)
 {
-	return container_of(dev, struct amd_iommu, iommu.dev);
+	struct iommu_device *iommu = dev_to_iommu_device(dev);
+
+	return container_of(iommu, struct amd_iommu, iommu);
 }
 
 #define ACPIHID_UID_LEN 256

drivers/iommu/intel-iommu.c

@@ -4736,7 +4736,9 @@ static void intel_disable_iommus(void)
 
 static inline struct intel_iommu *dev_to_intel_iommu(struct device *dev)
 {
-	return container_of(dev, struct intel_iommu, iommu.dev);
+	struct iommu_device *iommu_dev = dev_to_iommu_device(dev);
+
+	return container_of(iommu_dev, struct intel_iommu, iommu);
 }
 
 static ssize_t intel_iommu_show_version(struct device *dev,

drivers/iommu/iommu-sysfs.c

@@ -62,32 +62,40 @@ int iommu_device_sysfs_add(struct iommu_device *iommu,
 	va_list vargs;
 	int ret;
 
-	device_initialize(&iommu->dev);
+	iommu->dev = kzalloc(sizeof(*iommu->dev), GFP_KERNEL);
+	if (!iommu->dev)
+		return -ENOMEM;
 
-	iommu->dev.class = &iommu_class;
-	iommu->dev.parent = parent;
-	iommu->dev.groups = groups;
+	device_initialize(iommu->dev);
+
+	iommu->dev->class = &iommu_class;
+	iommu->dev->parent = parent;
+	iommu->dev->groups = groups;
 
 	va_start(vargs, fmt);
-	ret = kobject_set_name_vargs(&iommu->dev.kobj, fmt, vargs);
+	ret = kobject_set_name_vargs(&iommu->dev->kobj, fmt, vargs);
 	va_end(vargs);
 	if (ret)
 		goto error;
 
-	ret = device_add(&iommu->dev);
+	ret = device_add(iommu->dev);
 	if (ret)
 		goto error;
 
+	dev_set_drvdata(iommu->dev, iommu);
+
 	return 0;
 
 error:
-	put_device(&iommu->dev);
+	put_device(iommu->dev);
 	return ret;
 }
 
 void iommu_device_sysfs_remove(struct iommu_device *iommu)
 {
-	device_unregister(&iommu->dev);
+	dev_set_drvdata(iommu->dev, NULL);
+	device_unregister(iommu->dev);
+	iommu->dev = NULL;
 }
 /*
  * IOMMU drivers can indicate a device is managed by a given IOMMU using
@@ -102,14 +110,14 @@ int iommu_device_link(struct iommu_device *iommu, struct device *link)
 	if (!iommu || IS_ERR(iommu))
 		return -ENODEV;
 
-	ret = sysfs_add_link_to_group(&iommu->dev.kobj, "devices",
+	ret = sysfs_add_link_to_group(&iommu->dev->kobj, "devices",
 				      &link->kobj, dev_name(link));
 	if (ret)
 		return ret;
 
-	ret = sysfs_create_link_nowarn(&link->kobj, &iommu->dev.kobj, "iommu");
+	ret = sysfs_create_link_nowarn(&link->kobj, &iommu->dev->kobj, "iommu");
 	if (ret)
-		sysfs_remove_link_from_group(&iommu->dev.kobj, "devices",
+		sysfs_remove_link_from_group(&iommu->dev->kobj, "devices",
 					     dev_name(link));
 
 	return ret;
@@ -121,5 +129,5 @@ void iommu_device_unlink(struct iommu_device *iommu, struct device *link)
 		return;
 
 	sysfs_remove_link(&link->kobj, "iommu");
-	sysfs_remove_link_from_group(&iommu->dev.kobj, "devices", dev_name(link));
+	sysfs_remove_link_from_group(&iommu->dev->kobj, "devices", dev_name(link));
 }

include/linux/iommu.h

@@ -240,7 +240,7 @@ struct iommu_device {
 	struct list_head list;
 	const struct iommu_ops *ops;
 	struct fwnode_handle *fwnode;
-	struct device dev;
+	struct device *dev;
 };
 
 int  iommu_device_register(struct iommu_device *iommu);
@@ -265,6 +265,11 @@ static inline void iommu_device_set_fwnode(struct iommu_device *iommu,
 	iommu->fwnode = fwnode;
 }
 
+static inline struct iommu_device *dev_to_iommu_device(struct device *dev)
+{
+	return (struct iommu_device *)dev_get_drvdata(dev);
+}
+
 #define IOMMU_GROUP_NOTIFY_ADD_DEVICE		1 /* Device added */
 #define IOMMU_GROUP_NOTIFY_DEL_DEVICE		2 /* Pre Device removed */
 #define IOMMU_GROUP_NOTIFY_BIND_DRIVER		3 /* Pre Driver bind */
@@ -589,6 +594,11 @@ static inline void iommu_device_set_fwnode(struct iommu_device *iommu,
 {
 }
 
+static inline struct iommu_device *dev_to_iommu_device(struct device *dev)
+{
+	return NULL;
+}
+
 static inline void iommu_device_unregister(struct iommu_device *iommu)
 {
 }