[PATCH] vsock/virtio: annotate 'the_virtio_vsock' RCU pointer

From: Stefano Garzarella
Date: Fri Jul 10 2020 - 08:12:58 EST


Commit 0deab087b16a ("vsock/virtio: use RCU to avoid use-after-free
on the_virtio_vsock") starts to use RCU to protect 'the_virtio_vsock'
pointer, but we forgot to annotate it.

This patch adds the annotation to fix the following sparse errors:

net/vmw_vsock/virtio_transport.c:73:17: error: incompatible types in comparison expression (different address spaces):
net/vmw_vsock/virtio_transport.c:73:17: struct virtio_vsock [noderef] __rcu *
net/vmw_vsock/virtio_transport.c:73:17: struct virtio_vsock *
net/vmw_vsock/virtio_transport.c:171:17: error: incompatible types in comparison expression (different address spaces):
net/vmw_vsock/virtio_transport.c:171:17: struct virtio_vsock [noderef] __rcu *
net/vmw_vsock/virtio_transport.c:171:17: struct virtio_vsock *
net/vmw_vsock/virtio_transport.c:207:17: error: incompatible types in comparison expression (different address spaces):
net/vmw_vsock/virtio_transport.c:207:17: struct virtio_vsock [noderef] __rcu *
net/vmw_vsock/virtio_transport.c:207:17: struct virtio_vsock *
net/vmw_vsock/virtio_transport.c:561:13: error: incompatible types in comparison expression (different address spaces):
net/vmw_vsock/virtio_transport.c:561:13: struct virtio_vsock [noderef] __rcu *
net/vmw_vsock/virtio_transport.c:561:13: struct virtio_vsock *
net/vmw_vsock/virtio_transport.c:612:9: error: incompatible types in comparison expression (different address spaces):
net/vmw_vsock/virtio_transport.c:612:9: struct virtio_vsock [noderef] __rcu *
net/vmw_vsock/virtio_transport.c:612:9: struct virtio_vsock *
net/vmw_vsock/virtio_transport.c:631:9: error: incompatible types in comparison expression (different address spaces):
net/vmw_vsock/virtio_transport.c:631:9: struct virtio_vsock [noderef] __rcu *
net/vmw_vsock/virtio_transport.c:631:9: struct virtio_vsock *

Fixes: 0deab087b16a ("vsock/virtio: use RCU to avoid use-after-free on the_virtio_vsock")
Reported-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
---
net/vmw_vsock/virtio_transport.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index dfbaf6bd8b1c..2700a63ab095 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -22,7 +22,7 @@
#include <net/af_vsock.h>

static struct workqueue_struct *virtio_vsock_workqueue;
-static struct virtio_vsock *the_virtio_vsock;
+static struct virtio_vsock __rcu *the_virtio_vsock;
static DEFINE_MUTEX(the_virtio_vsock_mutex); /* protects the_virtio_vsock */

struct virtio_vsock {
--
2.26.2