Re: [GIT] HID updates for 2.6.29

[Jiri Kosina]

On Wed, 7 Jan 2009, Oliver Neukum wrote:

> > --- a/drivers/hid/usbhid/hiddev.c
> > +++ b/drivers/hid/usbhid/hiddev.c
> > @@ -885,6 +885,7 @@ int hiddev_connect(struct hid_device *hid, unsigned int force)
> >  	} else {
> >  		hid->minor = usbhid->intf->minor;
> >  		hiddev_table[usbhid->intf->minor - HIDDEV_MINOR_BASE] = hiddev;
> > +		hid->hiddev = hiddev;
> 
> It seems to me that this is still a race condition. What prevents open()
> from being called before this is set?

Right, there indeed is a tiny race window. Gabriel, could you please 
verify with the patch below instead? Thanks.


From: Jiri Kosina <jkosina@xxxxxxx>
Subject: [PATCH] HID: fix hid->hiddev initialization in hiddev_connect()

Commit 079034073fa ("HID: hiddev cleanup -- handle all error conditions
properly") by mistake removed proper initialization of hid->hiddev pointer
in hiddev_connect() in case usb_register_dev() succeeds for the hiddev node.
Put it properly back in place.

Reported-by: Gabriel C <nix.or.die@xxxxxxxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
---
 drivers/hid/usbhid/hiddev.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/hid/usbhid/hiddev.c b/drivers/hid/usbhid/hiddev.c
index 6a98f9f..d73eea3 100644
--- a/drivers/hid/usbhid/hiddev.c
+++ b/drivers/hid/usbhid/hiddev.c
@@ -874,12 +874,14 @@ int hiddev_connect(struct hid_device *hid, unsigned int force)
 	INIT_LIST_HEAD(&hiddev->list);
 	spin_lock_init(&hiddev->list_lock);
 	mutex_init(&hiddev->existancelock);
+	hid->hiddev = hiddev;
 	hiddev->hid = hid;
 	hiddev->exist = 1;
 
 	retval = usb_register_dev(usbhid->intf, &hiddev_class);
 	if (retval) {
 		err_hid("Not able to get a minor for this device.");
+		hid->hiddev = NULL;
 		kfree(hiddev);
 		return -1;
 	} else {
-- 
1.5.6

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