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author | Alan Stern <stern@rowland.harvard.edu> | 2008-03-03 15:16:04 -0500 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-04-24 21:16:33 -0700 |
commit | eb764c4be1e5db3ee34df5745e98cf2f148c7320 (patch) | |
tree | f434cf49540ab6ea2c7fae6490a693916c2e5501 /drivers/usb/core/hub.c | |
parent | feccc30d90155bcbc937f87643182a43d25873eb (diff) | |
download | op-kernel-dev-eb764c4be1e5db3ee34df5745e98cf2f148c7320.zip op-kernel-dev-eb764c4be1e5db3ee34df5745e98cf2f148c7320.tar.gz |
USB: check serial-number string after device reset
This patch (as1048) extends the descriptor checking after a device is
reset. Now the SerialNumber string descriptor is compared to its old
value, in addition to the device and configuration descriptors.
As a consequence, the kmalloc() call in usb_string() is now on the
error-handling pathway for usb-storage. Hence its allocation type is
changed to GFO_NOIO.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/core/hub.c')
-rw-r--r-- | drivers/usb/core/hub.c | 65 |
1 files changed, 50 insertions, 15 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 6dc5899..9fc5179 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -3010,16 +3010,36 @@ void usb_hub_cleanup(void) usb_deregister(&hub_driver); } /* usb_hub_cleanup() */ -static int config_descriptors_changed(struct usb_device *udev) -{ - unsigned index; - unsigned len = 0; - struct usb_config_descriptor *buf; +static int descriptors_changed(struct usb_device *udev, + struct usb_device_descriptor *old_device_descriptor) +{ + int changed = 0; + unsigned index; + unsigned serial_len = 0; + unsigned len; + unsigned old_length; + int length; + char *buf; + + if (memcmp(&udev->descriptor, old_device_descriptor, + sizeof(*old_device_descriptor)) != 0) + return 1; + + /* Since the idVendor, idProduct, and bcdDevice values in the + * device descriptor haven't changed, we will assume the + * Manufacturer and Product strings haven't changed either. + * But the SerialNumber string could be different (e.g., a + * different flash card of the same brand). + */ + if (udev->serial) + serial_len = strlen(udev->serial) + 1; + len = serial_len; for (index = 0; index < udev->descriptor.bNumConfigurations; index++) { - if (len < le16_to_cpu(udev->config[index].desc.wTotalLength)) - len = le16_to_cpu(udev->config[index].desc.wTotalLength); + old_length = le16_to_cpu(udev->config[index].desc.wTotalLength); + len = max(len, old_length); } + buf = kmalloc(len, GFP_NOIO); if (buf == NULL) { dev_err(&udev->dev, "no mem to re-read configs after reset\n"); @@ -3027,25 +3047,41 @@ static int config_descriptors_changed(struct usb_device *udev) return 1; } for (index = 0; index < udev->descriptor.bNumConfigurations; index++) { - int length; - int old_length = le16_to_cpu(udev->config[index].desc.wTotalLength); - + old_length = le16_to_cpu(udev->config[index].desc.wTotalLength); length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf, old_length); - if (length < old_length) { + if (length != old_length) { dev_dbg(&udev->dev, "config index %d, error %d\n", index, length); + changed = 1; break; } if (memcmp (buf, udev->rawdescriptors[index], old_length) != 0) { dev_dbg(&udev->dev, "config index %d changed (#%d)\n", - index, buf->bConfigurationValue); + index, + ((struct usb_config_descriptor *) buf)-> + bConfigurationValue); + changed = 1; break; } } + + if (!changed && serial_len) { + length = usb_string(udev, udev->descriptor.iSerialNumber, + buf, serial_len); + if (length + 1 != serial_len) { + dev_dbg(&udev->dev, "serial string error %d\n", + length); + changed = 1; + } else if (memcmp(buf, udev->serial, length) != 0) { + dev_dbg(&udev->dev, "serial string changed\n"); + changed = 1; + } + } + kfree(buf); - return index != udev->descriptor.bNumConfigurations; + return changed; } /** @@ -3118,8 +3154,7 @@ int usb_reset_device(struct usb_device *udev) goto re_enumerate; /* Device might have changed firmware (DFU or similar) */ - if (memcmp(&udev->descriptor, &descriptor, sizeof descriptor) - || config_descriptors_changed (udev)) { + if (descriptors_changed(udev, &descriptor)) { dev_info(&udev->dev, "device firmware changed\n"); udev->descriptor = descriptor; /* for disconnect() calls */ goto re_enumerate; |