[PATCH rdma-next 3/3] RDMA/cma: Let cma_resolve_ib_dev() continue search even after empty entry

[Leon Romanovsky]

From: Avihai Horon <avihaih@xxxxxxxxxx>

Currently, when cma_resolve_ib_dev() searches for a matching GID it will
stop searching after encountering the first empty GID table entry. This
behavior is wrong since neither IB nor RoCE spec enforce tightly packed
GID tables.

For example, when the matching valid GID entry exists at index N, and if
a GID entry is empty at index N-1, cma_resolve_ib_dev() will fail to
find the matching valid entry.

Fix it by making cma_resolve_ib_dev() continue searching even after
encountering missing entries.

Fixes: f17df3b0dede ("RDMA/cma: Add support for AF_IB to rdma_resolve_addr()")
Signed-off-by: Avihai Horon <avihaih@xxxxxxxxxx>
Reviewed-by: Mark Zhang <markzhang@xxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
---
 drivers/infiniband/core/cma.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 835ac54d4a24..b669002c9255 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -766,6 +766,7 @@ static int cma_resolve_ib_dev(struct rdma_id_private *id_priv)
 	unsigned int p;
 	u16 pkey, index;
 	enum ib_port_state port_state;
+	int ret;
 	int i;
 
 	cma_dev = NULL;
@@ -784,9 +785,16 @@ static int cma_resolve_ib_dev(struct rdma_id_private *id_priv)
 
 			if (ib_get_cached_port_state(cur_dev->device, p, &port_state))
 				continue;
-			for (i = 0; !rdma_query_gid(cur_dev->device,
-						    p, i, &gid);
-			     i++) {
+
+			for (i = 0; i < cur_dev->device->port_data[p].immutable.gid_tbl_len;
+			     ++i) {
+				ret = rdma_query_gid(cur_dev->device, p, i,
+						     &gid);
+				if (ret == -ENOENT)
+					continue;
+				if (ret)
+					break;
+
 				if (!memcmp(&gid, dgid, sizeof(gid))) {
 					cma_dev = cur_dev;
 					sgid = gid;
-- 
2.33.1