4.9-stable review patch. If anyone has any objections, please let me know.
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From: Shuah Khan (Samsung OSG) shuah@kernel.org
commit 7510df3f29d44685bab7b1918b61a8ccd57126a9 upstream.
After removing usbip_host module, devices it releases are left without a driver. For example, when a keyboard or a mass storage device are bound to usbip_host when it is removed, these devices are no longer bound to any driver.
Fix it to run device_attach() from the module exit routine to restore the devices to their original drivers. This includes cleanup changes and moving device_attach() code to a common routine to be called from rebind_store() and usbip_host_exit().
Signed-off-by: Shuah Khan (Samsung OSG) shuah@kernel.org Cc: stable stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/usb/usbip/stub_dev.c | 6 ---- drivers/usb/usbip/stub_main.c | 60 +++++++++++++++++++++++++++++++++++------- 2 files changed, 52 insertions(+), 14 deletions(-)
--- a/drivers/usb/usbip/stub_dev.c +++ b/drivers/usb/usbip/stub_dev.c @@ -462,12 +462,8 @@ static void stub_disconnect(struct usb_d busid_priv->sdev = NULL; stub_device_free(sdev);
- if (busid_priv->status == STUB_BUSID_ALLOC) { + if (busid_priv->status == STUB_BUSID_ALLOC) busid_priv->status = STUB_BUSID_ADDED; - } else { - busid_priv->status = STUB_BUSID_OTHER; - del_match_busid((char *)udev_busid); - } }
#ifdef CONFIG_PM --- a/drivers/usb/usbip/stub_main.c +++ b/drivers/usb/usbip/stub_main.c @@ -28,6 +28,7 @@ #define DRIVER_DESC "USB/IP Host Driver"
struct kmem_cache *stub_priv_cache; + /* * busid_tables defines matching busids that usbip can grab. A user can change * dynamically what device is locally used and what device is exported to a @@ -184,6 +185,51 @@ static ssize_t store_match_busid(struct static DRIVER_ATTR(match_busid, S_IRUSR | S_IWUSR, show_match_busid, store_match_busid);
+static int do_rebind(char *busid, struct bus_id_priv *busid_priv) +{ + int ret; + + /* device_attach() callers should hold parent lock for USB */ + if (busid_priv->udev->dev.parent) + device_lock(busid_priv->udev->dev.parent); + ret = device_attach(&busid_priv->udev->dev); + if (busid_priv->udev->dev.parent) + device_unlock(busid_priv->udev->dev.parent); + if (ret < 0) { + dev_err(&busid_priv->udev->dev, "rebind failed\n"); + return ret; + } + return 0; +} + +static void stub_device_rebind(void) +{ +#if IS_MODULE(CONFIG_USBIP_HOST) + struct bus_id_priv *busid_priv; + int i; + + /* update status to STUB_BUSID_OTHER so probe ignores the device */ + spin_lock(&busid_table_lock); + for (i = 0; i < MAX_BUSID; i++) { + if (busid_table[i].name[0] && + busid_table[i].shutdown_busid) { + busid_priv = &(busid_table[i]); + busid_priv->status = STUB_BUSID_OTHER; + } + } + spin_unlock(&busid_table_lock); + + /* now run rebind */ + for (i = 0; i < MAX_BUSID; i++) { + if (busid_table[i].name[0] && + busid_table[i].shutdown_busid) { + busid_priv = &(busid_table[i]); + do_rebind(busid_table[i].name, busid_priv); + } + } +#endif +} + static ssize_t rebind_store(struct device_driver *dev, const char *buf, size_t count) { @@ -204,16 +250,9 @@ static ssize_t rebind_store(struct devic /* mark the device for deletion so probe ignores it during rescan */ bid->status = STUB_BUSID_OTHER;
- /* device_attach() callers should hold parent lock for USB */ - if (bid->udev->dev.parent) - device_lock(bid->udev->dev.parent); - ret = device_attach(&bid->udev->dev); - if (bid->udev->dev.parent) - device_unlock(bid->udev->dev.parent); - if (ret < 0) { - dev_err(&bid->udev->dev, "rebind failed\n"); + ret = do_rebind((char *) buf, bid); + if (ret < 0) return ret; - }
/* delete device from busid_table */ del_match_busid((char *) buf); @@ -339,6 +378,9 @@ static void __exit usbip_host_exit(void) */ usb_deregister_device_driver(&stub_driver);
+ /* initiate scan to attach devices */ + stub_device_rebind(); + kmem_cache_destroy(stub_priv_cache); }