[PATCH RE-RESEND V2 for-next 4/5] IB/core: Make sure that the PSN does not overflow

Or Gerlitz
2015-02-05T11:53:51Z

From: Majd Dibbiny <majd-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>

The rq/sq->psn is 24 bits as defined in the IB spec, therefore ULPs and User
space applications shouldn't use the 8 most significant bits in the 32 bits
variables to avoid overflow in modify_qp.

Fixed the PSN generation by the RDMA-CM to mask out the 8 most significant bits,
also mask out these bits in uverbs for attributes provided by user-space.

Signed-off-by: Majd Dibbiny <majd-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Signed-off-by: Or Gerlitz <ogerlitz-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
---
drivers/infiniband/core/cma.c | 1 +
drivers/infiniband/core/uverbs_cmd.c | 4 ++--
2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index d570030..fab0ee5 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -512,6 +512,7 @@ struct rdma_cm_id *rdma_create_id(rdma_cm_event_handler event_handler,
INIT_LIST_HEAD(&id_priv->listen_list);
INIT_LIST_HEAD(&id_priv->mc_list);
get_random_bytes(&id_priv->seq_num, sizeof id_priv->seq_num);
+ id_priv->seq_num &= 0xffffff;

return &id_priv->id;
}
diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index 532d8eb..ecb6430 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -2053,8 +2053,8 @@ ssize_t ib_uverbs_modify_qp(struct ib_uverbs_file *file,
attr->path_mtu = cmd.path_mtu;
attr->path_mig_state = cmd.path_mig_state;
attr->qkey = cmd.qkey;
- attr->rq_psn = cmd.rq_psn;
- attr->sq_psn = cmd.sq_psn;
+ attr->rq_psn = cmd.rq_psn & 0xffffff;
+ attr->sq_psn = cmd.sq_psn & 0xffffff;
attr->dest_qp_num = cmd.dest_qp_num;
attr->qp_access_flags = cmd.qp_access_flags;
attr->pkey_index = cmd.pkey_index;
--
1.7.1