[PATCH net-next 3/9] rxrpc: The client call state must be changed before attachment to conn

From: David Howells
Date: Sun Sep 04 2016 - 17:13:56 EST


We must set the client call state to RXRPC_CALL_CLIENT_SEND_REQUEST before
attaching the call to the connection struct, not after, as it's liable to
receive errors and conn aborts as soon as the assignment is made - and
these will cause its state to be changed outside of the initiating thread's
control.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

net/rxrpc/call_object.c | 2 --
net/rxrpc/conn_client.c | 4 ++++
2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c
index 57e00fc9cff2..65691742199b 100644
--- a/net/rxrpc/call_object.c
+++ b/net/rxrpc/call_object.c
@@ -197,8 +197,6 @@ static int rxrpc_begin_client_call(struct rxrpc_call *call,
if (ret < 0)
return ret;

- call->state = RXRPC_CALL_CLIENT_SEND_REQUEST;
-
spin_lock(&call->conn->params.peer->lock);
hlist_add_head(&call->error_link, &call->conn->params.peer->error_targets);
spin_unlock(&call->conn->params.peer->lock);
diff --git a/net/rxrpc/conn_client.c b/net/rxrpc/conn_client.c
index 4b213bc0f554..e19804dd6c8d 100644
--- a/net/rxrpc/conn_client.c
+++ b/net/rxrpc/conn_client.c
@@ -537,6 +537,10 @@ static void rxrpc_activate_one_channel(struct rxrpc_connection *conn,
struct rxrpc_call, chan_wait_link);
u32 call_id = chan->call_counter + 1;

+ write_lock_bh(&call->state_lock);
+ call->state = RXRPC_CALL_CLIENT_SEND_REQUEST;
+ write_unlock_bh(&call->state_lock);
+
rxrpc_see_call(call);
list_del_init(&call->chan_wait_link);
conn->active_chans |= 1 << channel;