virtio_vop: don't kfree device on register failure

As mentioned at drivers/base/core.c:
/*
 * NOTE: _Never_ directly free @dev after calling this function, even
 * if it returned an error! Always use put_device() to give up the
 * reference initialized in this function instead.
 */
so we don't free vdev until vdev->vdev.dev.release be called.

Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 13 insertions, 7 deletions

diff --git a/drivers/misc/mic/vop/vop_main.c b/drivers/misc/mic/vop/vop_main.c
index a341938c7e2c..3633202e18f4 100644
--- a/drivers/misc/mic/vop/vop_main.c
+++ b/drivers/misc/mic/vop/vop_main.c
@@ -452,10 +452,12 @@ static irqreturn_t vop_virtio_intr_handler(int irq, void *data)
 
 static void vop_virtio_release_dev(struct device *_d)
 {
-        /*
-         * No need for a release method similar to virtio PCI.
-         * Provide an empty one to avoid getting a warning from core.
-         */
+        struct virtio_device *vdev =
+                        container_of(_d, struct virtio_device, dev);
+        struct _vop_vdev *vop_vdev =
+                        container_of(vdev, struct _vop_vdev, vdev);
+
+        kfree(vop_vdev);
 }
 
 /*
@@ -466,7 +468,7 @@ static int _vop_add_device(struct mic_device_desc __iomem *d,
                            unsigned int offset, struct vop_device *vpdev,
                            int dnode)
 {
-        struct _vop_vdev *vdev;
+        struct _vop_vdev *vdev, *reg_dev = NULL;
         int ret;
         u8 type = ioread8(&d->type);
 
@@ -497,6 +499,7 @@ static int _vop_add_device(struct mic_device_desc __iomem *d,
         vdev->c2h_vdev_db = ioread8(&vdev->dc->c2h_vdev_db);
 
         ret = register_virtio_device(&vdev->vdev);
+        reg_dev = vdev;
         if (ret) {
                 dev_err(_vop_dev(vdev),
                         "Failed to register vop device %u type %u\n",
@@ -512,7 +515,10 @@ static int _vop_add_device(struct mic_device_desc __iomem *d,
 free_irq:
         vpdev->hw_ops->free_irq(vpdev, vdev->virtio_cookie, vdev);
 kfree:
-        kfree(vdev);
+        if (reg_dev)
+                put_device(&vdev->vdev.dev);
+        else
+                kfree(vdev);
         return ret;
 }
 
@@ -568,7 +574,7 @@ static int _vop_remove_device(struct mic_device_desc __iomem *d,
                 iowrite8(-1, &dc->h2c_vdev_db);
                 if (status & VIRTIO_CONFIG_S_DRIVER_OK)
                         wait_for_completion(&vdev->reset_done);
-                kfree(vdev);
+                put_device(&vdev->vdev.dev);
                 iowrite8(1, &dc->guest_ack);
                 dev_dbg(&vpdev->dev, "%s %d guest_ack %d\n",
                         __func__, __LINE__, ioread8(&dc->guest_ack));