Commit 37e07cda authored by Bart Van Assche's avatar Bart Van Assche Committed by Doug Ledford
Browse files

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: default avatarBart 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: default avatarSean Hefty <sean.hefty@intel.com>
Reviewed-by: default avatarSteve Wise <swise@opengridcomputing.com>
Reviewed-by: default avatarLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
parent 8c5122e4

drivers/infiniband/core/cma.c

+26 −28
Original line number Diff line number Diff line
@@ -708,17 +708,6 @@ static void cma_deref_id(struct rdma_id_private *id_priv) 
		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 @@ static int cma_ib_handler(struct ib_cm_id *cm_id, struct ib_cm_event *ib_event) 
	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_check_req_qp_type(struct rdma_cm_id *id, struct ib_cm_event *ib_e 


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 @@ static int cma_req_handler(struct ib_cm_id *cm_id, struct ib_cm_event *ib_event) 
		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 @@ static int cma_iw_handler(struct iw_cm_id *iw_id, struct iw_cm_event *iw_event) 
	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 @@ static int cma_iw_handler(struct iw_cm_id *iw_id, struct iw_cm_event *iw_event) 
		return ret;

	}



out:

	mutex_unlock(&id_priv->handler_mutex);

	return ret;

}
@@ -2039,13 +2032,15 @@ static int iw_conn_req_handler(struct iw_cm_id *cm_id, 
	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 @@ static int cma_sidr_rep_handler(struct ib_cm_id *cm_id, 
	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 @@ static int cma_ib_mc_handler(int status, struct ib_sa_multicast *multicast) 
	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 @@ static int cma_ib_mc_handler(int status, struct ib_sa_multicast *multicast) 
		return 0;

	}



out:

	mutex_unlock(&id_priv->handler_mutex);

	return 0;

}

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