ses: close potential registration race
The slot and address fields have a small window of instability when
userspace can read them before initialization. Separate
enclosure_component
allocation from registration.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Jens Axboe <axboe@fb.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/drivers/misc/enclosure.c b/drivers/misc/enclosure.c
index 180a544..e18278a 100644
--- a/drivers/misc/enclosure.c
+++ b/drivers/misc/enclosure.c
@@ -273,27 +273,26 @@
static const struct attribute_group *enclosure_component_groups[];
/**
- * enclosure_component_register - add a particular component to an enclosure
+ * enclosure_component_alloc - prepare a new enclosure component
* @edev: the enclosure to add the component
* @num: the device number
* @type: the type of component being added
* @name: an optional name to appear in sysfs (leave NULL if none)
*
- * Registers the component. The name is optional for enclosures that
- * give their components a unique name. If not, leave the field NULL
- * and a name will be assigned.
+ * The name is optional for enclosures that give their components a unique
+ * name. If not, leave the field NULL and a name will be assigned.
*
* Returns a pointer to the enclosure component or an error.
*/
struct enclosure_component *
-enclosure_component_register(struct enclosure_device *edev,
- unsigned int number,
- enum enclosure_component_type type,
- const char *name)
+enclosure_component_alloc(struct enclosure_device *edev,
+ unsigned int number,
+ enum enclosure_component_type type,
+ const char *name)
{
struct enclosure_component *ecomp;
struct device *cdev;
- int err, i;
+ int i;
char newname[COMPONENT_NAME_SIZE];
if (number >= edev->components)
@@ -327,14 +326,30 @@
cdev->release = enclosure_component_release;
cdev->groups = enclosure_component_groups;
+ return ecomp;
+}
+EXPORT_SYMBOL_GPL(enclosure_component_alloc);
+
+/**
+ * enclosure_component_register - publishes an initialized enclosure component
+ * @ecomp: component to add
+ *
+ * Returns 0 on successful registration, releases the component otherwise
+ */
+int enclosure_component_register(struct enclosure_component *ecomp)
+{
+ struct device *cdev;
+ int err;
+
+ cdev = &ecomp->cdev;
err = device_register(cdev);
if (err) {
ecomp->number = -1;
put_device(cdev);
- return ERR_PTR(err);
+ return err;
}
- return ecomp;
+ return 0;
}
EXPORT_SYMBOL_GPL(enclosure_component_register);