From: Leon Romanovsky <leonro@mellanox.com>
Date: Mon, 4 May 2020 16:25:41 +0300
Subject: RDMA/ucma: Return stable IB device index as identifier
Patch-mainline: v5.8-rc1
Git-commit: 17793833f81ceb319be599ec09498ec0136d9acf
References: jsc#SLE-15176

The librdmacm uses node_guid as identifier to correlate between IB devices
and CMA devices. However FW resets cause to such "connection" to be lost
and require from the user to restart its application.

Extend UCMA to return IB device index, which is stable identifier.

Link: https://lore.kernel.org/r/20200504132541.355710-1-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/core/ucma.c   |   16 +++++++++-------
 include/uapi/rdma/rdma_user_cm.h |    4 ++++
 2 files changed, 13 insertions(+), 7 deletions(-)

--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -845,7 +845,7 @@ static ssize_t ucma_query_route(struct u
 	struct sockaddr *addr;
 	int ret = 0;
 
-	if (out_len < sizeof(resp))
+	if (out_len < offsetof(struct rdma_ucm_query_route_resp, ibdev_index))
 		return -ENOSPC;
 
 	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
@@ -869,6 +869,7 @@ static ssize_t ucma_query_route(struct u
 		goto out;
 
 	resp.node_guid = (__force __u64) ctx->cm_id->device->node_guid;
+	resp.ibdev_index = ctx->cm_id->device->index;
 	resp.port_num = ctx->cm_id->port_num;
 
 	if (rdma_cap_ib_sa(ctx->cm_id->device, ctx->cm_id->port_num))
@@ -880,8 +881,8 @@ static ssize_t ucma_query_route(struct u
 
 out:
 	mutex_unlock(&ctx->mutex);
-	if (copy_to_user(u64_to_user_ptr(cmd.response),
-			 &resp, sizeof(resp)))
+	if (copy_to_user(u64_to_user_ptr(cmd.response), &resp,
+			 min_t(size_t, out_len, sizeof(resp))))
 		ret = -EFAULT;
 
 	ucma_put_ctx(ctx);
@@ -895,6 +896,7 @@ static void ucma_query_device_addr(struc
 		return;
 
 	resp->node_guid = (__force __u64) cm_id->device->node_guid;
+	resp->ibdev_index = cm_id->device->index;
 	resp->port_num = cm_id->port_num;
 	resp->pkey = (__force __u16) cpu_to_be16(
 		     ib_addr_get_pkey(&cm_id->route.addr.dev_addr));
@@ -907,7 +909,7 @@ static ssize_t ucma_query_addr(struct uc
 	struct sockaddr *addr;
 	int ret = 0;
 
-	if (out_len < sizeof(resp))
+	if (out_len < offsetof(struct rdma_ucm_query_addr_resp, ibdev_index))
 		return -ENOSPC;
 
 	memset(&resp, 0, sizeof resp);
@@ -922,7 +924,7 @@ static ssize_t ucma_query_addr(struct uc
 
 	ucma_query_device_addr(ctx->cm_id, &resp);
 
-	if (copy_to_user(response, &resp, sizeof(resp)))
+	if (copy_to_user(response, &resp, min_t(size_t, out_len, sizeof(resp))))
 		ret = -EFAULT;
 
 	return ret;
@@ -974,7 +976,7 @@ static ssize_t ucma_query_gid(struct ucm
 	struct sockaddr_ib *addr;
 	int ret = 0;
 
-	if (out_len < sizeof(resp))
+	if (out_len < offsetof(struct rdma_ucm_query_addr_resp, ibdev_index))
 		return -ENOSPC;
 
 	memset(&resp, 0, sizeof resp);
@@ -1007,7 +1009,7 @@ static ssize_t ucma_query_gid(struct ucm
 						    &ctx->cm_id->route.addr.dst_addr);
 	}
 
-	if (copy_to_user(response, &resp, sizeof(resp)))
+	if (copy_to_user(response, &resp, min_t(size_t, out_len, sizeof(resp))))
 		ret = -EFAULT;
 
 	return ret;
--- a/include/uapi/rdma/rdma_user_cm.h
+++ b/include/uapi/rdma/rdma_user_cm.h
@@ -164,6 +164,8 @@ struct rdma_ucm_query_route_resp {
 	__u32 num_paths;
 	__u8 port_num;
 	__u8 reserved[3];
+	__u32 ibdev_index;
+	__u32 reserved1;
 };
 
 struct rdma_ucm_query_addr_resp {
@@ -175,6 +177,8 @@ struct rdma_ucm_query_addr_resp {
 	__u16 dst_size;
 	struct __kernel_sockaddr_storage src_addr;
 	struct __kernel_sockaddr_storage dst_addr;
+	__u32 ibdev_index;
+	__u32 reserved1;
 };
 
 struct rdma_ucm_query_path_resp {