platform/x86/intel/vsec: Use mutex for ida_alloc() and ida_free()

ID alloc and free functions don't have in built protection for parallel
invocation of ida_alloc() and ida_free(). With the current flow in the
vsec driver, there is no such scenario. But add mutex protection for
potential future changes.

Suggested-by: Hans de Goede <[email protected]>
Signed-off-by: Srinivas Pandruvada <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Hans de Goede <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>

Author: spandruvada

drivers/platform/x86/intel/vsec.c

@@ -129,11 +129,16 @@ static void intel_vsec_remove_aux(void *data)
 	auxiliary_device_uninit(data);
 }
 
+static DEFINE_MUTEX(vsec_ida_lock);
+
 static void intel_vsec_dev_release(struct device *dev)
 {
 	struct intel_vsec_device *intel_vsec_dev = dev_to_ivdev(dev);
 
+	mutex_lock(&vsec_ida_lock);
 	ida_free(intel_vsec_dev->ida, intel_vsec_dev->auxdev.id);
+	mutex_unlock(&vsec_ida_lock);
+
 	kfree(intel_vsec_dev->resource);
 	kfree(intel_vsec_dev);
 }
@@ -145,7 +150,9 @@ int intel_vsec_add_aux(struct pci_dev *pdev, struct device *parent,
 	struct auxiliary_device *auxdev = &intel_vsec_dev->auxdev;
 	int ret, id;
 
+	mutex_lock(&vsec_ida_lock);
 	ret = ida_alloc(intel_vsec_dev->ida, GFP_KERNEL);
+	mutex_unlock(&vsec_ida_lock);
 	if (ret < 0) {
 		kfree(intel_vsec_dev);
 		return ret;
@@ -161,7 +168,9 @@ int intel_vsec_add_aux(struct pci_dev *pdev, struct device *parent,
 
 	ret = auxiliary_device_init(auxdev);
 	if (ret < 0) {
+		mutex_lock(&vsec_ida_lock);
 		ida_free(intel_vsec_dev->ida, auxdev->id);
+		mutex_unlock(&vsec_ida_lock);
 		kfree(intel_vsec_dev->resource);
 		kfree(intel_vsec_dev);
 		return ret;