Re: [PATCH] USB: prevent char device open/deregister race
Greg KH <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
On Tue, May 22, 2007 at 11:46:41AM -0400, Alan Stern wrote: > This patch (as908) adds central protection in usbcore for the > prototypical race between opening and unregistering a char device. > The spinlock used to protect the minor-numbers array is replaced with > an rwsem, which can remain locked across a call to a driver's open() > method. This guarantees that open() and deregister() will be mutually > exclusive. Note that you missed some places in the sysvga driver, which I tried to fix up. You might want to check that I did this properly, just removing the lock felt "wrong" somehow :) Anyway, thanks a lot for doing this, it makes writing drivers much easier. Although I really hate rw locks, I'll let it go for now, we can easily change it to a "normal" mutex in the future... thanks, greg k-h ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel