USB: complain if userspace resets an active endpoint (f080a51b) · Commits · 戴 / test

It is an error for a driver to call usb_clear_halt() or usb_reset_endpoint() while there are URBs queued for the endpoint, because the end result is not well defined. At the time the endpoint gets reset, it may or may not be actively running. As far as I know, no kernel drivers do this. But some userspace drivers do, and it seems like a good idea to bring this error to their attention. This patch adds a warning to the kernel log whenever a program invokes the USBDEVFS_CLEAR_HALT or USBDEVFS_RESETEP ioctls at an inappropriate time, and includes the name of the program. This will make it clear that any subsequent errors are not due to the misbehavior of a kernel driver. Signed-off-by:

Alan Stern <stern@rowland.harvard.edu> Suggested-by:

Bjørn Mork <bjorn@mork.no> CC: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/devio.c

+16 −0

Original line number	Diff line number	Diff line
		@@ -1043,6 +1043,20 @@ static int proc_bulk(struct dev_state ps, void __user arg)
		return ret;
		}

		static void check_reset_of_active_ep(struct usb_device *udev,
		unsigned int epnum, char *ioctl_name)
		{
		struct usb_host_endpoint **eps;
		struct usb_host_endpoint *ep;

		eps = (epnum & USB_DIR_IN) ? udev->ep_in : udev->ep_out;
		ep = eps[epnum & 0x0f];
		if (ep && !list_empty(&ep->urb_list))
		dev_warn(&udev->dev, "Process %d (%s) called USBDEVFS_%s for active endpoint 0x%02x\n",
		task_pid_nr(current), current->comm,
		ioctl_name, epnum);
		}

		static int proc_resetep(struct dev_state ps, void __user arg)
		{
		unsigned int ep;
		@@ -1056,6 +1070,7 @@ static int proc_resetep(struct dev_state ps, void __user arg)
		ret = checkintf(ps, ret);
		if (ret)
		return ret;
		check_reset_of_active_ep(ps->dev, ep, "RESETEP");
		usb_reset_endpoint(ps->dev, ep);
		return 0;
		}
		@@ -1074,6 +1089,7 @@ static int proc_clearhalt(struct dev_state ps, void __user arg)
		ret = checkintf(ps, ret);
		if (ret)
		return ret;
		check_reset_of_active_ep(ps->dev, ep, "CLEAR_HALT");
		if (ep & USB_DIR_IN)
		pipe = usb_rcvbulkpipe(ps->dev, ep & 0x7f);
		else

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