From ca0c448d2b9f43e3175835d536853854ef544e22 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?H=C3=A5kon=20Bugge?= Date: Tue, 22 Jun 2021 15:39:57 +0200 Subject: [PATCH] RDMA/cma: Protect RMW with qp_mutex MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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()") Link: https://lore.kernel.org/r/1624369197-24578-3-git-send-email-haakon.bugge@oracle.com Signed-off-by: Håkon Bugge Signed-off-by: Jason Gunthorpe --- drivers/infiniband/core/cma.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index e3f52c516094..6b6fa82e7943 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) @@ -3067,8 +3080,10 @@ static int cma_resolve_iboe_route(struct rdma_id_private *id_priv) * PacketLifeTime = local ACK timeout/2 * as a reasonable approximation for RoCE networks. */ + mutex_lock(&id_priv->qp_mutex); route->path_rec->packet_life_time = id_priv->timeout_set ? id_priv->timeout - 1 : CMA_IBOE_PACKET_LIFETIME; + mutex_unlock(&id_priv->qp_mutex); if (!route->path_rec->mtu) { ret = -EINVAL; @@ -4092,8 +4107,11 @@ 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),