IB/cma: Make the code easier to verify
Static source code analysis tools like smatch cannot handle functions
that lock or not lock a mutex depending on the value of the arguments.
Hence inline the function cma_disable_callback(). Additionally, this
patch realizes a small performance optimization by reducing the number of
mutex_lock() and mutex_unlock() calls in the modified functions. With
this patch applied smatch no longer complains about source file cma.c.
Without this patch smatch reports the following for this source file:
drivers/infiniband/core/cma.c:1959: cma_req_handler() warn: inconsistent returns 'mutex:&listen_id->handler_mutex'.
Locked on: line 1880
line 1959
Unlocked on: line 1941
drivers/infiniband/core/cma.c:2112: iw_conn_req_handler() warn: inconsistent returns 'mutex:&listen_id->handler_mutex'.
Locked on: line 2048
Unlocked on: line 2112
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Steve Wise <swise@opengridcomputing.com>
Cc: Leon Romanovsky <leonro@mellanox.com>
Acked-by: Sean Hefty <sean.hefty@intel.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index f0c91ba..c58ee77 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -708,17 +708,6 @@
complete(&id_priv->comp);
}
-static int cma_disable_callback(struct rdma_id_private *id_priv,
- enum rdma_cm_state state)
-{
- mutex_lock(&id_priv->handler_mutex);
- if (id_priv->state != state) {
- mutex_unlock(&id_priv->handler_mutex);
- return -EINVAL;
- }
- return 0;
-}
-
struct rdma_cm_id *rdma_create_id(struct net *net,
rdma_cm_event_handler event_handler,
void *context, enum rdma_port_space ps,
@@ -1671,11 +1660,12 @@
struct rdma_cm_event event;
int ret = 0;
+ mutex_lock(&id_priv->handler_mutex);
if ((ib_event->event != IB_CM_TIMEWAIT_EXIT &&
- cma_disable_callback(id_priv, RDMA_CM_CONNECT)) ||
+ id_priv->state != RDMA_CM_CONNECT) ||
(ib_event->event == IB_CM_TIMEWAIT_EXIT &&
- cma_disable_callback(id_priv, RDMA_CM_DISCONNECT)))
- return 0;
+ id_priv->state != RDMA_CM_DISCONNECT))
+ goto out;
memset(&event, 0, sizeof event);
switch (ib_event->event) {
@@ -1870,7 +1860,7 @@
static int cma_req_handler(struct ib_cm_id *cm_id, struct ib_cm_event *ib_event)
{
- struct rdma_id_private *listen_id, *conn_id;
+ struct rdma_id_private *listen_id, *conn_id = NULL;
struct rdma_cm_event event;
struct net_device *net_dev;
int offset, ret;
@@ -1884,9 +1874,10 @@
goto net_dev_put;
}
- if (cma_disable_callback(listen_id, RDMA_CM_LISTEN)) {
+ mutex_lock(&listen_id->handler_mutex);
+ if (listen_id->state != RDMA_CM_LISTEN) {
ret = -ECONNABORTED;
- goto net_dev_put;
+ goto err1;
}
memset(&event, 0, sizeof event);
@@ -1976,8 +1967,9 @@
struct sockaddr *laddr = (struct sockaddr *)&iw_event->local_addr;
struct sockaddr *raddr = (struct sockaddr *)&iw_event->remote_addr;
- if (cma_disable_callback(id_priv, RDMA_CM_CONNECT))
- return 0;
+ mutex_lock(&id_priv->handler_mutex);
+ if (id_priv->state != RDMA_CM_CONNECT)
+ goto out;
memset(&event, 0, sizeof event);
switch (iw_event->event) {
@@ -2029,6 +2021,7 @@
return ret;
}
+out:
mutex_unlock(&id_priv->handler_mutex);
return ret;
}
@@ -2039,13 +2032,15 @@
struct rdma_cm_id *new_cm_id;
struct rdma_id_private *listen_id, *conn_id;
struct rdma_cm_event event;
- int ret;
+ int ret = -ECONNABORTED;
struct sockaddr *laddr = (struct sockaddr *)&iw_event->local_addr;
struct sockaddr *raddr = (struct sockaddr *)&iw_event->remote_addr;
listen_id = cm_id->context;
- if (cma_disable_callback(listen_id, RDMA_CM_LISTEN))
- return -ECONNABORTED;
+
+ mutex_lock(&listen_id->handler_mutex);
+ if (listen_id->state != RDMA_CM_LISTEN)
+ goto out;
/* Create a new RDMA id for the new IW CM ID */
new_cm_id = rdma_create_id(listen_id->id.route.addr.dev_addr.net,
@@ -3216,8 +3211,9 @@
struct ib_cm_sidr_rep_event_param *rep = &ib_event->param.sidr_rep_rcvd;
int ret = 0;
- if (cma_disable_callback(id_priv, RDMA_CM_CONNECT))
- return 0;
+ mutex_lock(&id_priv->handler_mutex);
+ if (id_priv->state != RDMA_CM_CONNECT)
+ goto out;
memset(&event, 0, sizeof event);
switch (ib_event->event) {
@@ -3673,12 +3669,13 @@
struct rdma_id_private *id_priv;
struct cma_multicast *mc = multicast->context;
struct rdma_cm_event event;
- int ret;
+ int ret = 0;
id_priv = mc->id_priv;
- if (cma_disable_callback(id_priv, RDMA_CM_ADDR_BOUND) &&
- cma_disable_callback(id_priv, RDMA_CM_ADDR_RESOLVED))
- return 0;
+ mutex_lock(&id_priv->handler_mutex);
+ if (id_priv->state != RDMA_CM_ADDR_BOUND &&
+ id_priv->state != RDMA_CM_ADDR_RESOLVED)
+ goto out;
if (!status)
status = cma_set_qkey(id_priv, be32_to_cpu(multicast->rec.qkey));
@@ -3720,6 +3717,7 @@
return 0;
}
+out:
mutex_unlock(&id_priv->handler_mutex);
return 0;
}