Netvsc: Call hv_unmap_memory() in the netvsc_device_remove()

netvsc_device_remove() calls vunmap() inside which should not be
called in the interrupt context. Current code calls hv_unmap_memory()
in the free_netvsc_device() which is rcu callback and maybe called
in the interrupt context. This will trigger BUG_ON(in_interrupt())
in the vunmap(). Fix it via moving hv_unmap_memory() to netvsc_device_
remove().

Fixes: 846da38de0e8 ("net: netvsc: Add Isolation VM support for netvsc driver")
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index afa81a9480ccd88e045dfc31d90ee947e116d48f..e675d1016c3c8346d31a63bd1d055eda7de2d2a8 100644 (file)
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -154,19 +154,15 @@ static void free_netvsc_device(struct rcu_head *head)
 
        kfree(nvdev->extension);
 
-       if (nvdev->recv_original_buf) {
-               hv_unmap_memory(nvdev->recv_buf);
+       if (nvdev->recv_original_buf)
                vfree(nvdev->recv_original_buf);
-       } else {
+       else
                vfree(nvdev->recv_buf);
-       }
 
-       if (nvdev->send_original_buf) {
-               hv_unmap_memory(nvdev->send_buf);
+       if (nvdev->send_original_buf)
                vfree(nvdev->send_original_buf);
-       } else {
+       else
                vfree(nvdev->send_buf);
-       }
 
        bitmap_free(nvdev->send_section_map);
 
@@ -765,6 +761,12 @@ void netvsc_device_remove(struct hv_device *device)
                netvsc_teardown_send_gpadl(device, net_device, ndev);
        }
 
+       if (net_device->recv_original_buf)
+               hv_unmap_memory(net_device->recv_buf);
+
+       if (net_device->send_original_buf)
+               hv_unmap_memory(net_device->send_buf);
+
        /* Release all resources */
        free_netvsc_device_rcu(net_device);
 }
@@ -1821,6 +1823,12 @@ cleanup:
        netif_napi_del(&net_device->chan_table[0].napi);
 
 cleanup2:
+       if (net_device->recv_original_buf)
+               hv_unmap_memory(net_device->recv_buf);
+
+       if (net_device->send_original_buf)
+               hv_unmap_memory(net_device->send_buf);
+
        free_netvsc_device(&net_device->rcu);
 
        return ERR_PTR(ret);