usb: gadget: Move kstrtox() out of lock

The kstrtox() calls operate on local (to the function) variables and do
not need to be serialized. We may call them out of the lock.
Reviewed-by: John Keeping <john@metanate.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230120182434.24245-1-andriy.shevchenko@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/configfs.c

@@ -808,15 +808,15 @@ static ssize_t webusb_use_store(struct config_item *item, const char *page,
 	int ret;
 	bool use;
 
-	mutex_lock(&gi->lock);
 	ret = kstrtobool(page, &use);
-	if (!ret) {
+	if (ret)
+		return ret;
+
+	mutex_lock(&gi->lock);
 	gi->use_webusb = use;
-		ret = len;
-	}
 	mutex_unlock(&gi->lock);
 
-	return ret;
+	return len;
 }
 
 static ssize_t webusb_bcdVersion_show(struct config_item *item, char *page)
@@ -832,10 +832,12 @@ static ssize_t webusb_bcdVersion_store(struct config_item *item,
 	u16 bcdVersion;
 	int ret;
 
-	mutex_lock(&gi->lock);
 	ret = kstrtou16(page, 0, &bcdVersion);
 	if (ret)
-		goto out;
+		return ret;
+
+	mutex_lock(&gi->lock);
+
 	ret = is_valid_bcd(bcdVersion);
 	if (ret)
 		goto out;
@@ -862,15 +864,15 @@ static ssize_t webusb_bVendorCode_store(struct config_item *item,
 	int ret;
 	u8 b_vendor_code;
 
-	mutex_lock(&gi->lock);
 	ret = kstrtou8(page, 0, &b_vendor_code);
-	if (!ret) {
+	if (ret)
+		return ret;
+
+	mutex_lock(&gi->lock);
 	gi->b_webusb_vendor_code = b_vendor_code;
-		ret = len;
-	}
 	mutex_unlock(&gi->lock);
 
-	return ret;
+	return len;
 }
 
 static ssize_t webusb_landingPage_show(struct config_item *item, char *page)
@@ -956,15 +958,15 @@ static ssize_t os_desc_use_store(struct config_item *item, const char *page,
 	int ret;
 	bool use;
 
-	mutex_lock(&gi->lock);
 	ret = kstrtobool(page, &use);
-	if (!ret) {
+	if (ret)
+		return ret;
+
+	mutex_lock(&gi->lock);
 	gi->use_os_desc = use;
-		ret = len;
-	}
 	mutex_unlock(&gi->lock);
 
-	return ret;
+	return len;
 }
 
 static ssize_t os_desc_b_vendor_code_show(struct config_item *item, char *page)
@@ -980,15 +982,15 @@ static ssize_t os_desc_b_vendor_code_store(struct config_item *item,
 	int ret;
 	u8 b_vendor_code;
 
-	mutex_lock(&gi->lock);
 	ret = kstrtou8(page, 0, &b_vendor_code);
-	if (!ret) {
+	if (ret)
+		return ret;
+
+	mutex_lock(&gi->lock);
 	gi->b_vendor_code = b_vendor_code;
-		ret = len;
-	}
 	mutex_unlock(&gi->lock);
 
-	return ret;
+	return len;
 }
 
 static ssize_t os_desc_qw_sign_show(struct config_item *item, char *page)
@@ -1113,15 +1115,15 @@ static ssize_t ext_prop_type_store(struct config_item *item,
 	u8 type;
 	int ret;
 
-	if (desc->opts_mutex)
-		mutex_lock(desc->opts_mutex);
 	ret = kstrtou8(page, 0, &type);
 	if (ret)
-		goto end;
-	if (type < USB_EXT_PROP_UNICODE || type > USB_EXT_PROP_UNICODE_MULTI) {
-		ret = -EINVAL;
-		goto end;
-	}
+		return ret;
+
+	if (type < USB_EXT_PROP_UNICODE || type > USB_EXT_PROP_UNICODE_MULTI)
+		return -EINVAL;
+
+	if (desc->opts_mutex)
+		mutex_lock(desc->opts_mutex);
 
 	if ((ext_prop->type == USB_EXT_PROP_BINARY ||
 	    ext_prop->type == USB_EXT_PROP_LE32 ||
@@ -1138,12 +1140,10 @@ static ssize_t ext_prop_type_store(struct config_item *item,
 		   type == USB_EXT_PROP_BE32))
 		ext_prop->data_len >>= 1;
 	ext_prop->type = type;
-	ret = len;
 
-end:
 	if (desc->opts_mutex)
 		mutex_unlock(desc->opts_mutex);
-	return ret;
+	return len;
 }
 
 static ssize_t ext_prop_data_show(struct config_item *item, char *page)