Messages in this thread |  | | | Subject | Re: Flaw in the driver-model implementation of attributes | | From | Jeremy Fitzhardinge <> | | Date | 15 Jun 2003 10:40:45 -0700 |
| |
On Sun, 2003-06-15 at 09:42, Alan Stern wrote: > If you're already aware of this, please forgive the intrusion. > > There's a general problem in the driver model's implementation of > attribute files, in connection with loadable kernel modules. The > sysfs_ops structure stores function pointers with no means for identifying > the module that contains the corresponding code. As a result, it's > possible to call through one of these pointers even after the module has > been unloaded, causing an oops. > > It's not hard to provoke this sort of situation. A user process can > open a sysfs device file, for instance, and delay trying to read it until > the module containing the device driver has been removed. When the read > does occur, it runs into trouble.
I've seen this oops when a program has its cwd in a /sys directory corresponding to a removed (or replaced) module. I think active references to a part of the /sys namespace corresponding to a module should just pin the module. But I haven't looked into it really.
J
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |