[dpdk-dev] [PATCH] vhost: fix crash on unregistering in client mode

[dpdk-dev] [PATCH] vhost: fix crash on unregistering in client mode

[Qiang Zhou]

when rte_vhost_driver_unregister delete the connection fd,
the fd lock will prevent the vsocket to be freed. But when vhost_user_msg_handler
return error, it will delete vsocket conn_list. And then the fd lock will become
invalid. So the vsocket will be freed in rte_vhost_drivere_unregister and the
vhost_user_read_cb will reconnect.

To fix this:
move delete vsocket conn after reconnect

Cc: stable@dpdk.org

Signed-off-by: Qiang Zhou <zhouqiang2633@gmail.com>
---
 lib/librte_vhost/socket.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
index d63031747..43da1c51b 100644
--- a/lib/librte_vhost/socket.c
+++ b/lib/librte_vhost/socket.c
@@ -293,16 +293,16 @@ vhost_user_read_cb(int connfd, void *dat, int *remove)
 		if (vsocket->notify_ops->destroy_connection)
 			vsocket->notify_ops->destroy_connection(conn->vid);
 
+		if (vsocket->reconnect) {
+			create_unix_socket(vsocket);
+			vhost_user_start_client(vsocket);
+		}
+
 		pthread_mutex_lock(&vsocket->conn_mutex);
 		TAILQ_REMOVE(&vsocket->conn_list, conn, next);
 		pthread_mutex_unlock(&vsocket->conn_mutex);
 
 		free(conn);
-
-		if (vsocket->reconnect) {
-			create_unix_socket(vsocket);
-			vhost_user_start_client(vsocket);
-		}
 	}
 }
 
-- 
2.14.3 (Apple Git-98)

[dpdk-dev] [PATCH] vhost: fix crash on unregistering in client mode

[Qiang Zhou]

when rte_vhost_driver_unregister delete the connection fd,
the fd lock will prevent the vsocket to be freed. But when
vhost_user_msg_handler return error, it will delete vsocket
conn_list. And then the fd lock will become invalid. So the
vsocket will be freed in rte_vhost_drivere_unregister and
the vhost_user_read_cb will reconnect.

To fix this:
move delete vsocket conn after reconnect

Cc: stable@dpdk.org

Signed-off-by: Qiang Zhou <zhouqiang2633@gmail.com>
---
 lib/librte_vhost/socket.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
index d63031747..43da1c51b 100644
--- a/lib/librte_vhost/socket.c
+++ b/lib/librte_vhost/socket.c
@@ -293,16 +293,16 @@ vhost_user_read_cb(int connfd, void *dat, int *remove)
 		if (vsocket->notify_ops->destroy_connection)
 			vsocket->notify_ops->destroy_connection(conn->vid);
 
+		if (vsocket->reconnect) {
+			create_unix_socket(vsocket);
+			vhost_user_start_client(vsocket);
+		}
+
 		pthread_mutex_lock(&vsocket->conn_mutex);
 		TAILQ_REMOVE(&vsocket->conn_list, conn, next);
 		pthread_mutex_unlock(&vsocket->conn_mutex);
 
 		free(conn);
-
-		if (vsocket->reconnect) {
-			create_unix_socket(vsocket);
-			vhost_user_start_client(vsocket);
-		}
 	}
 }
 
-- 
2.14.3 (Apple Git-98)

Re: [dpdk-dev] [PATCH] vhost: fix crash on unregistering in client mode

[Maxime Coquelin]

Hi Qiang,

On 09/07/2018 02:53 AM, Qiang Zhou wrote:
> when rte_vhost_driver_unregister delete the connection fd,
> the fd lock will prevent the vsocket to be freed. But when
> vhost_user_msg_handler return error, it will delete vsocket
> conn_list. And then the fd lock will become invalid. So the
> vsocket will be freed in rte_vhost_drivere_unregister and
> the vhost_user_read_cb will reconnect.

I am not sure to understand the problem, could you please
elaborate?

> 
> To fix this:
> move delete vsocket conn after reconnect
> 
> Cc: stable@dpdk.org
> 
> Signed-off-by: Qiang Zhou <zhouqiang2633@gmail.com>
> ---
>   lib/librte_vhost/socket.c | 10 +++++-----
>   1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
> index d63031747..43da1c51b 100644
> --- a/lib/librte_vhost/socket.c
> +++ b/lib/librte_vhost/socket.c
> @@ -293,16 +293,16 @@ vhost_user_read_cb(int connfd, void *dat, int *remove)
>   		if (vsocket->notify_ops->destroy_connection)
>   			vsocket->notify_ops->destroy_connection(conn->vid);
>   
> +		if (vsocket->reconnect) {
> +			create_unix_socket(vsocket);
> +			vhost_user_start_client(vsocket);
> +		}
> +
>   		pthread_mutex_lock(&vsocket->conn_mutex);
>   		TAILQ_REMOVE(&vsocket->conn_list, conn, next);
>   		pthread_mutex_unlock(&vsocket->conn_mutex);
>   
>   		free(conn);
> -
> -		if (vsocket->reconnect) {
> -			create_unix_socket(vsocket);
> -			vhost_user_start_client(vsocket);
> -		}
>   	}
>   }
>   
>