[PATCH] driver core: fix device_add error path

Dmitriy Monakhov
2007-03-11T12:36:38Z

Dmitriy Monakhov <dmonakhov@sw.ru> writes:

> Greg Kroah-Hartman <gregkh@suse.de> writes:
>
>> From: James Simmons <jsimmons@infradead.org>
>>
>> When a device fails to register the class symlinks where not cleaned up.
>> This left a symlink in the /sys/class/"device"/ directory that pointed
>> to no where. This caused the sysfs_follow_link Oops I reported earlier.
>> This patch cleanups up the symlink. Please apply. Thank you.
>>
>> Signed-Off: James Simmons <jsimmons@infradead.org>
>> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
>> ---
>> drivers/base/core.c | 31 ++++++++++++++++++++++++++++++-
>> 1 files changed, 30 insertions(+), 1 deletions(-)
>>
>> diff --git a/drivers/base/core.c b/drivers/base/core.c
>> index d04fd33..cf2a398 100644
>> --- a/drivers/base/core.c
>> +++ b/drivers/base/core.c
>> @@ -637,12 +637,41 @@ int device_add(struct device *dev)
>> BUS_NOTIFY_DEL_DEVICE, dev);
>> device_remove_groups(dev);
>> GroupError:
>> - device_remove_attrs(dev);
>> + device_remove_attrs(dev);
>> AttrsError:
>> if (dev->devt_attr) {
>> device_remove_file(dev, dev->devt_attr);
>> kfree(dev->devt_attr);
>> }
>> +
>> + if (dev->class) {
>> + sysfs_remove_link(&dev->kobj, "subsystem");
>> + /* If this is not a "fake" compatible device, remove the
>> + * symlink from the class to the device. */
>> + if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
>> + sysfs_remove_link(&dev->class->subsys.kset.kobj,
>> + dev->bus_id);
>> +#ifdef CONFIG_SYSFS_DEPRECATED
>> + if (parent) {
>> + char *class_name = make_class_name(dev->class->name,
>> + &dev->kobj);
>> + if (class_name)
>> + sysfs_remove_link(&dev->parent->kobj,
>> + class_name);
>> + kfree(class_name);
>> + sysfs_remove_link(&dev->kobj, "device");
>> + }
>> +#endif
>> +
> <<<<< block begin
>> + down(&dev->class->sem);
>> + /* notify any interfaces that the device is now gone */
>> + list_for_each_entry(class_intf, &dev->class->interfaces, node)
>> + if (class_intf->remove_dev)
>> + class_intf->remove_dev(dev, class_intf);
>> + /* remove the device from the class list */
>> + list_del_init(&dev->node);
>> + up(&dev->class->sem);
> <<<<<< block end
> May be i've missed something, but i'm confuesd a litle bit.
> For example if error happens while device_pm_add() we jump to label "PMError"
> and code from block above will be executed (device will be remove from list),
> but this device wasn't added to this list yet!
I've check it one more time, code it really broken!, and i think i understand how
this can happen ....
it look like full code chunck was copy-pasted from device_del(), but in case of
device_add() error path, device was't added to dev->class->devices list yet.
Folowing patch fix this copy-paste error:

[PATCH] driver core: fix device_add error path

- At the moment we jump here device was't added to
dev->class->devices list yet.

Signed-off-by: Monakhov Dmitriy <dmonakhov@openvz.org>
---
drivers/base/core.c | 9 ---------
1 files changed, 0 insertions(+), 9 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 142c222..7d2459b 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -684,15 +684,6 @@ int device_add(struct device *dev)
#endif
sysfs_remove_link(&dev->kobj, "device");
}
-
- down(&dev->class->sem);
- /* notify any interfaces that the device is now gone */
- list_for_each_entry(class_intf, &dev->class->interfaces, node)
- if (class_intf->remove_dev)
- class_intf->remove_dev(dev, class_intf);
- /* remove the device from the class list */
- list_del_init(&dev->node);
- up(&dev->class->sem);
}
ueventattrError:
device_remove_file(dev, &dev->uevent_attr);
--
1.5.0.1