Merge tag 'char-misc-6.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char / misc fixes from Greg KH:
 "Here are some small char/misc fixes for 6.11-rc4 to resolve reported
  problems. Included in here are:

   - fastrpc revert of a change that broke userspace

   - xillybus fixes for reported issues

  Half of these have been in linux-next this week with no reported
  problems, I don't know if the last bit of xillybus driver changes made
  it in, but they are 'obviously correct' so will be safe :)"

* tag 'char-misc-6.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  char: xillybus: Check USB endpoints when probing device
  char: xillybus: Refine workqueue handling
  Revert "misc: fastrpc: Restrict untrusted app to attach to privileged PD"
  char: xillybus: Don't destroy workqueue from work item running on it

Author: torvalds

drivers/char/xillybus/xillyusb.c

@@ -50,6 +50,7 @@ MODULE_LICENSE("GPL v2");
 static const char xillyname[] = "xillyusb";
 
 static unsigned int fifo_buf_order;
+static struct workqueue_struct *wakeup_wq;
 
 #define USB_VENDOR_ID_XILINX		0x03fd
 #define USB_VENDOR_ID_ALTERA		0x09fb
@@ -569,10 +570,6 @@ static void cleanup_dev(struct kref *kref)
  * errors if executed. The mechanism relies on that xdev->error is assigned
  * a non-zero value by report_io_error() prior to queueing wakeup_all(),
  * which prevents bulk_in_work() from calling process_bulk_in().
- *
- * The fact that wakeup_all() and bulk_in_work() are queued on the same
- * workqueue makes their concurrent execution very unlikely, however the
- * kernel's API doesn't seem to ensure this strictly.
  */
 
 static void wakeup_all(struct work_struct *work)
@@ -627,7 +624,7 @@ static void report_io_error(struct xillyusb_dev *xdev,
 
 	if (do_once) {
 		kref_get(&xdev->kref); /* xdev is used by work item */
-		queue_work(xdev->workq, &xdev->wakeup_workitem);
+		queue_work(wakeup_wq, &xdev->wakeup_workitem);
 	}
 }
 
@@ -1906,6 +1903,13 @@ static const struct file_operations xillyusb_fops = {
 
 static int xillyusb_setup_base_eps(struct xillyusb_dev *xdev)
 {
+	struct usb_device *udev = xdev->udev;
+
+	/* Verify that device has the two fundamental bulk in/out endpoints */
+	if (usb_pipe_type_check(udev, usb_sndbulkpipe(udev, MSG_EP_NUM)) ||
+	    usb_pipe_type_check(udev, usb_rcvbulkpipe(udev, IN_EP_NUM)))
+		return -ENODEV;
+
 	xdev->msg_ep = endpoint_alloc(xdev, MSG_EP_NUM | USB_DIR_OUT,
 				      bulk_out_work, 1, 2);
 	if (!xdev->msg_ep)
@@ -1935,14 +1939,15 @@ static int setup_channels(struct xillyusb_dev *xdev,
 			  __le16 *chandesc,
 			  int num_channels)
 {
-	struct xillyusb_channel *chan;
+	struct usb_device *udev = xdev->udev;
+	struct xillyusb_channel *chan, *new_channels;
 	int i;
 
 	chan = kcalloc(num_channels, sizeof(*chan), GFP_KERNEL);
 	if (!chan)
 		return -ENOMEM;
 
-	xdev->channels = chan;
+	new_channels = chan;
 
 	for (i = 0; i < num_channels; i++, chan++) {
 		unsigned int in_desc = le16_to_cpu(*chandesc++);
@@ -1971,6 +1976,15 @@ static int setup_channels(struct xillyusb_dev *xdev,
 		 */
 
 		if ((out_desc & 0x80) && i < 14) { /* Entry is valid */
+			if (usb_pipe_type_check(udev,
+						usb_sndbulkpipe(udev, i + 2))) {
+				dev_err(xdev->dev,
+					"Missing BULK OUT endpoint %d\n",
+					i + 2);
+				kfree(new_channels);
+				return -ENODEV;
+			}
+
 			chan->writable = 1;
 			chan->out_synchronous = !!(out_desc & 0x40);
 			chan->out_seekable = !!(out_desc & 0x20);
@@ -1980,6 +1994,7 @@ static int setup_channels(struct xillyusb_dev *xdev,
 		}
 	}
 
+	xdev->channels = new_channels;
 	return 0;
 }
 
@@ -2096,9 +2111,11 @@ static int xillyusb_discovery(struct usb_interface *interface)
 	 * just after responding with the IDT, there is no reason for any
 	 * work item to be running now. To be sure that xdev->channels
 	 * is updated on anything that might run in parallel, flush the
-	 * workqueue, which rarely does anything.
+	 * device's workqueue and the wakeup work item. This rarely
+	 * does anything.
 	 */
 	flush_workqueue(xdev->workq);
+	flush_work(&xdev->wakeup_workitem);
 
 	xdev->num_channels = num_channels;
 
@@ -2258,19 +2275,28 @@ static int __init xillyusb_init(void)
 {
 	int rc = 0;
 
+	wakeup_wq = alloc_workqueue(xillyname, 0, 0);
+	if (!wakeup_wq)
+		return -ENOMEM;
+
 	if (LOG2_INITIAL_FIFO_BUF_SIZE > PAGE_SHIFT)
 		fifo_buf_order = LOG2_INITIAL_FIFO_BUF_SIZE - PAGE_SHIFT;
 	else
 		fifo_buf_order = 0;
 
 	rc = usb_register(&xillyusb_driver);
 
+	if (rc)
+		destroy_workqueue(wakeup_wq);
+
 	return rc;
 }
 
 static void __exit xillyusb_exit(void)
 {
 	usb_deregister(&xillyusb_driver);
+
+	destroy_workqueue(wakeup_wq);
 }
 
 module_init(xillyusb_init);

drivers/misc/fastrpc.c

@@ -2085,16 +2085,6 @@ static int fastrpc_req_mem_map(struct fastrpc_user *fl, char __user *argp)
 	return err;
 }
 
-static int is_attach_rejected(struct fastrpc_user *fl)
-{
-	/* Check if the device node is non-secure */
-	if (!fl->is_secure_dev) {
-		dev_dbg(&fl->cctx->rpdev->dev, "untrusted app trying to attach to privileged DSP PD\n");
-		return -EACCES;
-	}
-	return 0;
-}
-
 static long fastrpc_device_ioctl(struct file *file, unsigned int cmd,
 				 unsigned long arg)
 {
@@ -2107,19 +2097,13 @@ static long fastrpc_device_ioctl(struct file *file, unsigned int cmd,
 		err = fastrpc_invoke(fl, argp);
 		break;
 	case FASTRPC_IOCTL_INIT_ATTACH:
-		err = is_attach_rejected(fl);
-		if (!err)
-			err = fastrpc_init_attach(fl, ROOT_PD);
+		err = fastrpc_init_attach(fl, ROOT_PD);
 		break;
 	case FASTRPC_IOCTL_INIT_ATTACH_SNS:
-		err = is_attach_rejected(fl);
-		if (!err)
-			err = fastrpc_init_attach(fl, SENSORS_PD);
+		err = fastrpc_init_attach(fl, SENSORS_PD);
 		break;
 	case FASTRPC_IOCTL_INIT_CREATE_STATIC:
-		err = is_attach_rejected(fl);
-		if (!err)
-			err = fastrpc_init_create_static_process(fl, argp);
+		err = fastrpc_init_create_static_process(fl, argp);
 		break;
 	case FASTRPC_IOCTL_INIT_CREATE:
 		err = fastrpc_init_create_process(fl, argp);

include/uapi/misc/fastrpc.h

@@ -8,14 +8,11 @@
 #define FASTRPC_IOCTL_ALLOC_DMA_BUFF	_IOWR('R', 1, struct fastrpc_alloc_dma_buf)
 #define FASTRPC_IOCTL_FREE_DMA_BUFF	_IOWR('R', 2, __u32)
 #define FASTRPC_IOCTL_INVOKE		_IOWR('R', 3, struct fastrpc_invoke)
-/* This ioctl is only supported with secure device nodes */
 #define FASTRPC_IOCTL_INIT_ATTACH	_IO('R', 4)
 #define FASTRPC_IOCTL_INIT_CREATE	_IOWR('R', 5, struct fastrpc_init_create)
 #define FASTRPC_IOCTL_MMAP		_IOWR('R', 6, struct fastrpc_req_mmap)
 #define FASTRPC_IOCTL_MUNMAP		_IOWR('R', 7, struct fastrpc_req_munmap)
-/* This ioctl is only supported with secure device nodes */
 #define FASTRPC_IOCTL_INIT_ATTACH_SNS	_IO('R', 8)
-/* This ioctl is only supported with secure device nodes */
 #define FASTRPC_IOCTL_INIT_CREATE_STATIC _IOWR('R', 9, struct fastrpc_init_create_static)
 #define FASTRPC_IOCTL_MEM_MAP		_IOWR('R', 10, struct fastrpc_mem_map)
 #define FASTRPC_IOCTL_MEM_UNMAP		_IOWR('R', 11, struct fastrpc_mem_unmap)