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 <hdegoede@redhat.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Link: https://lore.kernel.org/r/20230207125821.3837799-1-srinivas.pandruvada@linux.intel.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/drivers/platform/x86/intel/vsec.c b/drivers/platform/x86/intel/vsec.c
index b936fc5..f1680b7 100644 (file)
--- a/drivers/platform/x86/intel/vsec.c
+++ b/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;