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authorHans Petter Selasky <hselasky@FreeBSD.org>2016-06-03 08:58:26 +0000
committerHans Petter Selasky <hselasky@FreeBSD.org>2016-06-03 08:58:26 +0000
commit22523b3a7a371a8d11499d99b83decd8123eda76 (patch)
tree165bbd0299060a00730720db76809ea84f8d3bb8
parent6fbb70afb8f487935f6f2fbd0f97c22761538e71 (diff)
downloadsrc-22523b3a7a371a8d11499d99b83decd8123eda76.tar.gz
src-22523b3a7a371a8d11499d99b83decd8123eda76.zip
MFC r300667:
Check for signals when locking the USB enumeration thread from userspace, so that USB applications can be killed if an enumeration thread should be stuck for various reasons.
Notes
Notes: svn path=/stable/8/; revision=301255
-rw-r--r--sys/dev/usb/usb_dev.c8
-rw-r--r--sys/dev/usb/usb_device.c23
-rw-r--r--sys/dev/usb/usb_device.h3
3 files changed, 32 insertions, 2 deletions
diff --git a/sys/dev/usb/usb_dev.c b/sys/dev/usb/usb_dev.c
index ed7f468eb150..376d1546b569 100644
--- a/sys/dev/usb/usb_dev.c
+++ b/sys/dev/usb/usb_dev.c
@@ -223,7 +223,7 @@ usb_ref_device(struct usb_cdev_privdata *cpd,
* We need to grab the enumeration SX-lock before
* grabbing the FIFO refs to avoid deadlock at detach!
*/
- crd->do_unlock = usbd_enum_lock(cpd->udev);
+ crd->do_unlock = usbd_enum_lock_sig(cpd->udev);
mtx_lock(&usb_ref_lock);
@@ -231,6 +231,12 @@ usb_ref_device(struct usb_cdev_privdata *cpd,
* Set "is_uref" after grabbing the default SX lock
*/
crd->is_uref = 1;
+
+ /* check for signal */
+ if (crd->do_unlock > 1) {
+ crd->do_unlock = 0;
+ goto error;
+ }
}
/* check if we are doing an open */
diff --git a/sys/dev/usb/usb_device.c b/sys/dev/usb/usb_device.c
index 20321fdda86e..638aef41c9ea 100644
--- a/sys/dev/usb/usb_device.c
+++ b/sys/dev/usb/usb_device.c
@@ -2768,7 +2768,7 @@ usbd_device_attached(struct usb_device *udev)
/*
* The following function locks enumerating the given USB device. If
* the lock is already grabbed this function returns zero. Else a
- * non-zero value is returned.
+ * a value of one is returned.
*/
uint8_t
usbd_enum_lock(struct usb_device *udev)
@@ -2787,6 +2787,27 @@ usbd_enum_lock(struct usb_device *udev)
return (1);
}
+#if USB_HAVE_UGEN
+/*
+ * This function is the same like usbd_enum_lock() except a value of
+ * 255 is returned when a signal is pending:
+ */
+uint8_t
+usbd_enum_lock_sig(struct usb_device *udev)
+{
+ if (sx_xlocked(&udev->enum_sx))
+ return (0);
+ if (sx_xlock_sig(&udev->enum_sx))
+ return (255);
+ if (sx_xlock_sig(&udev->sr_sx)) {
+ sx_xunlock(&udev->enum_sx);
+ return (255);
+ }
+ mtx_lock(&Giant);
+ return (1);
+}
+#endif
+
/* The following function unlocks enumerating the given USB device. */
void
diff --git a/sys/dev/usb/usb_device.h b/sys/dev/usb/usb_device.h
index 172023254acc..b4ff58f225ff 100644
--- a/sys/dev/usb/usb_device.h
+++ b/sys/dev/usb/usb_device.h
@@ -303,6 +303,9 @@ void usb_set_device_state(struct usb_device *, enum usb_dev_state);
enum usb_dev_state usb_get_device_state(struct usb_device *);
uint8_t usbd_enum_lock(struct usb_device *);
+#if USB_HAVE_UGEN
+uint8_t usbd_enum_lock_sig(struct usb_device *);
+#endif
void usbd_enum_unlock(struct usb_device *);
void usbd_sr_lock(struct usb_device *);
void usbd_sr_unlock(struct usb_device *);