RDMA/core: Do not invoke init_port on compat devices

The driver interface cannot manipulate the sysfs of the compat device,
only of the full device so we must avoid calling the driver sysfs APIs on
compat devices.

This prevents an oops:

 Call Trace:
 dump_stack+0x5a/0x73
 kobject_init+0x74/0x80
 kobject_init_and_add+0x35/0xb0
 hfi1_create_port_files+0x6e/0x3c0 [hfi1]
 ib_setup_port_attrs+0x43b/0x560 [ib_core]
 add_one_compat_dev+0x16a/0x230 [ib_core]
 rdma_dev_init_net+0x110/0x160 [ib_core]
 ops_init+0x38/0xf0
 setup_net+0xcf/0x1e0
 copy_net_ns+0xb7/0x130
 create_new_namespaces+0x11a/0x1b0
 unshare_nsproxy_namespaces+0x55/0xa0
 ksys_unshare+0x1a7/0x340
 __x64_sys_unshare+0xe/0x20
 do_syscall_64+0x5b/0x180
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 5417783e ("RDMA/core: Support core port attributes in non init_net")
Reported-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Tested-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/core/core_priv.h

@@ -341,8 +341,7 @@ int roce_resolve_route_from_path(struct sa_path_rec *rec,
 struct net_device *rdma_read_gid_attr_ndev_rcu(const struct ib_gid_attr *attr);
 
 void ib_free_port_attrs(struct ib_core_device *coredev);
-int ib_setup_port_attrs(struct ib_core_device *coredev,
-			bool alloc_hw_stats);
+int ib_setup_port_attrs(struct ib_core_device *coredev);
 
 int rdma_compatdev_set(u8 enable);
 

drivers/infiniband/core/device.c

@@ -870,7 +870,7 @@ static int add_one_compat_dev(struct ib_device *device,
 	ret = device_add(&cdev->dev);
 	if (ret)
 		goto add_err;
-	ret = ib_setup_port_attrs(cdev, false);
+	ret = ib_setup_port_attrs(cdev);
 	if (ret)
 		goto port_err;
 

drivers/infiniband/core/sysfs.c

@@ -1015,10 +1015,10 @@ static void setup_hw_stats(struct ib_device *device, struct ib_port *port,
 	return;
 }
 
-static int add_port(struct ib_core_device *coredev,
-		    int port_num, bool alloc_stats)
+static int add_port(struct ib_core_device *coredev, int port_num)
 {
 	struct ib_device *device = rdma_device_to_ibdev(&coredev->dev);
+	bool is_full_dev = &device->coredev == coredev;
 	struct ib_port *p;
 	struct ib_port_attr attr;
 	int i;
@@ -1057,7 +1057,7 @@ static int add_port(struct ib_core_device *coredev,
 		goto err_put;
 	}
 
-	if (device->ops.process_mad && alloc_stats) {
+	if (device->ops.process_mad && is_full_dev) {
 		p->pma_table = get_counter_table(device, port_num);
 		ret = sysfs_create_group(&p->kobj, p->pma_table);
 		if (ret)
@@ -1113,7 +1113,7 @@ static int add_port(struct ib_core_device *coredev,
 	if (ret)
 		goto err_free_pkey;
 
-	if (device->ops.init_port) {
+	if (device->ops.init_port && is_full_dev) {
 		ret = device->ops.init_port(device, port_num, &p->kobj);
 		if (ret)
 			goto err_remove_pkey;
@@ -1124,7 +1124,7 @@ static int add_port(struct ib_core_device *coredev,
 	 * port, so holder should be device. Therefore skip per port conunter
 	 * initialization.
 	 */
-	if (device->ops.alloc_hw_stats && port_num && alloc_stats)
+	if (device->ops.alloc_hw_stats && port_num && is_full_dev)
 		setup_hw_stats(device, p, port_num);
 
 	list_add_tail(&p->kobj.entry, &coredev->port_list);
@@ -1308,7 +1308,7 @@ void ib_free_port_attrs(struct ib_core_device *coredev)
 	kobject_put(coredev->ports_kobj);
 }
 
-int ib_setup_port_attrs(struct ib_core_device *coredev, bool alloc_stats)
+int ib_setup_port_attrs(struct ib_core_device *coredev)
 {
 	struct ib_device *device = rdma_device_to_ibdev(&coredev->dev);
 	unsigned int port;
@@ -1320,7 +1320,7 @@ int ib_setup_port_attrs(struct ib_core_device *coredev, bool alloc_stats)
 		return -ENOMEM;
 
 	rdma_for_each_port (device, port) {
-		ret = add_port(coredev, port, alloc_stats);
+		ret = add_port(coredev, port);
 		if (ret)
 			goto err_put;
 	}
@@ -1336,7 +1336,7 @@ int ib_device_register_sysfs(struct ib_device *device)
 {
 	int ret;
 
-	ret = ib_setup_port_attrs(&device->coredev, true);
+	ret = ib_setup_port_attrs(&device->coredev);
 	if (ret)
 		return ret;