diff mbox series

[for-next,2/2] RDMA/cma: Protect RMW with qp_mutex

Message ID 1624368030-23214-3-git-send-email-haakon.bugge@oracle.com (mailing list archive)
State Superseded
Headers show
Series Fix RMW to bit-fields and remove one superfluous ib_modify_qp | expand

Commit Message

Haakon Bugge June 22, 2021, 1:20 p.m. UTC 
The struct rdma_id_private contains three bit-fields, tos_set,
timeout_set, and min_rnr_timer_set. These are set by accessor
functions without any synchronization. If two or all accessor
functions are invoked in close proximity in time, there will be
Read-Modify-Write from several contexts to the same variable, and the
result will be intermittent.

Fixed by protecting the bit-fields by the qp_mutex in the accessor
functions.

The consumer of timeout_set and min_rnr_timer_set is in
rdma_init_qp_attr(), which is called with qp_mutex held for connected
QPs. Explicit locking is added for the consumers of tos and tos_set.

This commit depends on ("RDMA/cma: Remove unnecessary INIT->INIT
transition"), since the call to rdma_init_qp_attr() from
cma_init_conn_qp() does not hold the qp_mutex.

Fixes: 2c1619edef61 ("IB/cma: Define option to set ack timeout and pack tos_set")
Fixes: 3aeffc46afde ("IB/cma: Introduce rdma_set_min_rnr_timer()")
Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
---
 drivers/infiniband/core/cma.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

Comments

Haakon Bugge June 22, 2021, 1:30 p.m. UTC | #1 
> On 22 Jun 2021, at 15:20, Håkon Bugge <haakon.bugge@oracle.com> wrote:
> 
> The struct rdma_id_private contains three bit-fields, tos_set,
> timeout_set, and min_rnr_timer_set. These are set by accessor
> functions without any synchronization. If two or all accessor
> functions are invoked in close proximity in time, there will be
> Read-Modify-Write from several contexts to the same variable, and the
> result will be intermittent.
> 
> Fixed by protecting the bit-fields by the qp_mutex in the accessor
> functions.
> 
> The consumer of timeout_set and min_rnr_timer_set is in
> rdma_init_qp_attr(), which is called with qp_mutex held for connected
> QPs. Explicit locking is added for the consumers of tos and tos_set.
> 
> This commit depends on ("RDMA/cma: Remove unnecessary INIT->INIT
> transition"), since the call to rdma_init_qp_attr() from
> cma_init_conn_qp() does not hold the qp_mutex.
> 
> Fixes: 2c1619edef61 ("IB/cma: Define option to set ack timeout and pack tos_set")
> Fixes: 3aeffc46afde ("IB/cma: Introduce rdma_set_min_rnr_timer()")
> Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>

Sorry, not my day. Overlooked the access to timeout_set/timeout in  cma_resolve_iboe_route().

Have to send a v2.



Håkon

> ---
> drivers/infiniband/core/cma.c | 18 +++++++++++++++++-
> 1 file changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
> index e3f52c5..6b41527 100644
> --- a/drivers/infiniband/core/cma.c
> +++ b/drivers/infiniband/core/cma.c
> @@ -2457,8 +2457,10 @@ static int cma_iw_listen(struct rdma_id_private *id_priv, int backlog)
> 	if (IS_ERR(id))
> 		return PTR_ERR(id);
> 
> +	mutex_lock(&id_priv->qp_mutex);
> 	id->tos = id_priv->tos;
> 	id->tos_set = id_priv->tos_set;
> +	mutex_unlock(&id_priv->qp_mutex);
> 	id->afonly = id_priv->afonly;
> 	id_priv->cm_id.iw = id;
> 
> @@ -2519,8 +2521,10 @@ static int cma_listen_on_dev(struct rdma_id_private *id_priv,
> 	cma_id_get(id_priv);
> 	dev_id_priv->internal_id = 1;
> 	dev_id_priv->afonly = id_priv->afonly;
> +	mutex_lock(&id_priv->qp_mutex);
> 	dev_id_priv->tos_set = id_priv->tos_set;
> 	dev_id_priv->tos = id_priv->tos;
> +	mutex_unlock(&id_priv->qp_mutex);
> 
> 	ret = rdma_listen(&dev_id_priv->id, id_priv->backlog);
> 	if (ret)
> @@ -2567,8 +2571,10 @@ void rdma_set_service_type(struct rdma_cm_id *id, int tos)
> 	struct rdma_id_private *id_priv;
> 
> 	id_priv = container_of(id, struct rdma_id_private, id);
> +	mutex_lock(&id_priv->qp_mutex);
> 	id_priv->tos = (u8) tos;
> 	id_priv->tos_set = true;
> +	mutex_unlock(&id_priv->qp_mutex);
> }
> EXPORT_SYMBOL(rdma_set_service_type);
> 
> @@ -2595,8 +2601,10 @@ int rdma_set_ack_timeout(struct rdma_cm_id *id, u8 timeout)
> 		return -EINVAL;
> 
> 	id_priv = container_of(id, struct rdma_id_private, id);
> +	mutex_lock(&id_priv->qp_mutex);
> 	id_priv->timeout = timeout;
> 	id_priv->timeout_set = true;
> +	mutex_unlock(&id_priv->qp_mutex);
> 
> 	return 0;
> }
> @@ -2632,8 +2640,10 @@ int rdma_set_min_rnr_timer(struct rdma_cm_id *id, u8 min_rnr_timer)
> 		return -EINVAL;
> 
> 	id_priv = container_of(id, struct rdma_id_private, id);
> +	mutex_lock(&id_priv->qp_mutex);
> 	id_priv->min_rnr_timer = min_rnr_timer;
> 	id_priv->min_rnr_timer_set = true;
> +	mutex_unlock(&id_priv->qp_mutex);
> 
> 	return 0;
> }
> @@ -3019,8 +3029,11 @@ static int cma_resolve_iboe_route(struct rdma_id_private *id_priv)
> 
> 	u8 default_roce_tos = id_priv->cma_dev->default_roce_tos[id_priv->id.port_num -
> 					rdma_start_port(id_priv->cma_dev->device)];
> -	u8 tos = id_priv->tos_set ? id_priv->tos : default_roce_tos;
> +	u8 tos;
> 
> +	mutex_lock(&id_priv->qp_mutex);
> +	tos = id_priv->tos_set ? id_priv->tos : default_roce_tos;
> +	mutex_unlock(&id_priv->qp_mutex);
> 
> 	work = kzalloc(sizeof *work, GFP_KERNEL);
> 	if (!work)
> @@ -4092,8 +4105,11 @@ static int cma_connect_iw(struct rdma_id_private *id_priv,
> 	if (IS_ERR(cm_id))
> 		return PTR_ERR(cm_id);
> 
> +	mutex_lock(&id_priv->qp_mutex);
> 	cm_id->tos = id_priv->tos;
> 	cm_id->tos_set = id_priv->tos_set;
> +	mutex_unlock(&id_priv->qp_mutex);
> +
> 	id_priv->cm_id.iw = cm_id;
> 
> 	memcpy(&cm_id->local_addr, cma_src_addr(id_priv),
> -- 
> 1.8.3.1
>
diff mbox series

Patch

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index e3f52c5..6b41527 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -2457,8 +2457,10 @@  static int cma_iw_listen(struct rdma_id_private *id_priv, int backlog)
 	if (IS_ERR(id))
 		return PTR_ERR(id);
 
+	mutex_lock(&id_priv->qp_mutex);
 	id->tos = id_priv->tos;
 	id->tos_set = id_priv->tos_set;
+	mutex_unlock(&id_priv->qp_mutex);
 	id->afonly = id_priv->afonly;
 	id_priv->cm_id.iw = id;
 
@@ -2519,8 +2521,10 @@  static int cma_listen_on_dev(struct rdma_id_private *id_priv,
 	cma_id_get(id_priv);
 	dev_id_priv->internal_id = 1;
 	dev_id_priv->afonly = id_priv->afonly;
+	mutex_lock(&id_priv->qp_mutex);
 	dev_id_priv->tos_set = id_priv->tos_set;
 	dev_id_priv->tos = id_priv->tos;
+	mutex_unlock(&id_priv->qp_mutex);
 
 	ret = rdma_listen(&dev_id_priv->id, id_priv->backlog);
 	if (ret)
@@ -2567,8 +2571,10 @@  void rdma_set_service_type(struct rdma_cm_id *id, int tos)
 	struct rdma_id_private *id_priv;
 
 	id_priv = container_of(id, struct rdma_id_private, id);
+	mutex_lock(&id_priv->qp_mutex);
 	id_priv->tos = (u8) tos;
 	id_priv->tos_set = true;
+	mutex_unlock(&id_priv->qp_mutex);
 }
 EXPORT_SYMBOL(rdma_set_service_type);
 
@@ -2595,8 +2601,10 @@  int rdma_set_ack_timeout(struct rdma_cm_id *id, u8 timeout)
 		return -EINVAL;
 
 	id_priv = container_of(id, struct rdma_id_private, id);
+	mutex_lock(&id_priv->qp_mutex);
 	id_priv->timeout = timeout;
 	id_priv->timeout_set = true;
+	mutex_unlock(&id_priv->qp_mutex);
 
 	return 0;
 }
@@ -2632,8 +2640,10 @@  int rdma_set_min_rnr_timer(struct rdma_cm_id *id, u8 min_rnr_timer)
 		return -EINVAL;
 
 	id_priv = container_of(id, struct rdma_id_private, id);
+	mutex_lock(&id_priv->qp_mutex);
 	id_priv->min_rnr_timer = min_rnr_timer;
 	id_priv->min_rnr_timer_set = true;
+	mutex_unlock(&id_priv->qp_mutex);
 
 	return 0;
 }
@@ -3019,8 +3029,11 @@  static int cma_resolve_iboe_route(struct rdma_id_private *id_priv)
 
 	u8 default_roce_tos = id_priv->cma_dev->default_roce_tos[id_priv->id.port_num -
 					rdma_start_port(id_priv->cma_dev->device)];
-	u8 tos = id_priv->tos_set ? id_priv->tos : default_roce_tos;
+	u8 tos;
 
+	mutex_lock(&id_priv->qp_mutex);
+	tos = id_priv->tos_set ? id_priv->tos : default_roce_tos;
+	mutex_unlock(&id_priv->qp_mutex);
 
 	work = kzalloc(sizeof *work, GFP_KERNEL);
 	if (!work)
@@ -4092,8 +4105,11 @@  static int cma_connect_iw(struct rdma_id_private *id_priv,
 	if (IS_ERR(cm_id))
 		return PTR_ERR(cm_id);
 
+	mutex_lock(&id_priv->qp_mutex);
 	cm_id->tos = id_priv->tos;
 	cm_id->tos_set = id_priv->tos_set;
+	mutex_unlock(&id_priv->qp_mutex);
+
 	id_priv->cm_id.iw = cm_id;
 
 	memcpy(&cm_id->local_addr, cma_src_addr(id_priv),