Re: [PATCH]: Fix deadlock in USBIP driver (staging), linux-2.6.34-rc5

[Greg KH <gregkh@suse.de>]

On Thu, Apr 22, 2010 at 06:54:02PM +0200, Eric Lescouet wrote:
> Hi,
> When detaching a port from the client side (usbip --detach 0),
> the event thread, on the server side, is going to deadlock.
> The "eh" server thread is getting USBIP_EH_RESET event and calls:
>  -> stub_device_reset() -> usb_reset_device()
> the USB framework is then calling back _in the same "eh" thread_ :
>  -> stub_disconnect() -> usbip_stop_eh() -> wait_for_completion()
> the "eh" thread is being asleep forever, waiting for its own completion.
> The patch checks if "eh" is the current thread, in usbip_stop_eh().

Ok, but does the lock_kernel() call you just made actually prevent this
from happening?  Isn't there some other lock you can use instead?

> Please Cc me in reply, I'm not in the list.

Also, to have patches that we can apply, we need a "Signed-off-by:"
line.  See the file, Documentation/SubmittingPatches for what this
means.
> 
> b.r.
> 
> ------------------
> 
> diff -Nur linux-2.6.34-rc5/drivers/staging/usbip/usbip_event.c
> linux-2.6.34-rc5.new/drivers/staging/usbip/usbip_event.c
> --- linux-2.6.34-rc5/drivers/staging/usbip/usbip_event.c
> 2010-04-20 01:29:56.000000000 +0200

Your email client wrapped the patch and made it unappliable :(

thanks,

greg k-h