RDMA: Provide safe ib_alloc_device() function

All callers to ib_alloc_device() provide a larger size than struct
ib_device and rely on the fact that struct ib_device is embedded in their
driver specific structure as the first member.

Provide a safer variant of ib_alloc_device() that checks and enforces this
approach to make sure the drivers are using it right.
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/core/device.c

@@ -268,7 +268,7 @@ static struct class ib_class = {
 };
 
 /**
- * ib_alloc_device - allocate an IB device struct
+ * _ib_alloc_device - allocate an IB device struct
  * @size:size of structure to allocate
  *
  * Low-level drivers should use ib_alloc_device() to allocate &struct
@@ -277,7 +277,7 @@ static struct class ib_class = {
  * ib_dealloc_device() must be used to free structures allocated with
  * ib_alloc_device().
  */
-struct ib_device *ib_alloc_device(size_t size)
+struct ib_device *_ib_alloc_device(size_t size)
 {
 	struct ib_device *device;
 
@@ -303,7 +303,7 @@ struct ib_device *ib_alloc_device(size_t size)
 
 	return device;
 }
-EXPORT_SYMBOL(ib_alloc_device);
+EXPORT_SYMBOL(_ib_alloc_device);
 
 /**
  * ib_dealloc_device - free an IB device struct

drivers/infiniband/hw/bnxt_re/main.c

@@ -688,7 +688,7 @@ static struct bnxt_re_dev *bnxt_re_dev_add(struct net_device *netdev,
 	struct bnxt_re_dev *rdev;
 
 	/* Allocate bnxt_re_dev instance here */
-	rdev = (struct bnxt_re_dev *)ib_alloc_device(sizeof(*rdev));
+	rdev = ib_alloc_device(bnxt_re_dev, ibdev);
 	if (!rdev) {
 		dev_err(NULL, "%s: bnxt_re_dev allocation failure!",
 			ROCE_DRV_MODULE_NAME);

drivers/infiniband/hw/cxgb3/iwch.c

@@ -146,7 +146,7 @@ static void open_rnic_dev(struct t3cdev *tdev)
 
 	pr_debug("%s t3cdev %p\n", __func__,  tdev);
 	pr_info_once("Chelsio T3 RDMA Driver - version %s\n", DRV_VERSION);
-	rnicp = (struct iwch_dev *)ib_alloc_device(sizeof(*rnicp));
+	rnicp = ib_alloc_device(iwch_dev, ibdev);
 	if (!rnicp) {
 		pr_err("Cannot allocate ib device\n");
 		return;

drivers/infiniband/hw/cxgb4/device.c

@@ -966,7 +966,7 @@ static struct c4iw_dev *c4iw_alloc(const struct cxgb4_lld_info *infop)
 		pr_info("%s: On-Chip Queues not supported on this device\n",
 			pci_name(infop->pdev));
 
-	devp = (struct c4iw_dev *)ib_alloc_device(sizeof(*devp));
+	devp = ib_alloc_device(c4iw_dev, ibdev);
 	if (!devp) {
 		pr_err("Cannot allocate ib device\n");
 		return ERR_PTR(-ENOMEM);

drivers/infiniband/hw/hns/hns_roce_hw_v1.c

@@ -5002,7 +5002,7 @@ static int hns_roce_probe(struct platform_device *pdev)
 	struct hns_roce_dev *hr_dev;
 	struct device *dev = &pdev->dev;
 
-	hr_dev = (struct hns_roce_dev *)ib_alloc_device(sizeof(*hr_dev));
+	hr_dev = ib_alloc_device(hns_roce_dev, ib_dev);
 	if (!hr_dev)
 		return -ENOMEM;
 

drivers/infiniband/hw/hns/hns_roce_hw_v2.c

@@ -6059,7 +6059,7 @@ static int hns_roce_hw_v2_init_instance(struct hnae3_handle *handle)
 	struct hns_roce_dev *hr_dev;
 	int ret;
 
-	hr_dev = (struct hns_roce_dev *)ib_alloc_device(sizeof(*hr_dev));
+	hr_dev = ib_alloc_device(hns_roce_dev, ib_dev);
 	if (!hr_dev)
 		return -ENOMEM;
 

drivers/infiniband/hw/i40iw/i40iw_verbs.c

@@ -2762,7 +2762,7 @@ static struct i40iw_ib_device *i40iw_init_rdma_device(struct i40iw_device *iwdev
 	struct net_device *netdev = iwdev->netdev;
 	struct pci_dev *pcidev = (struct pci_dev *)iwdev->hw.dev_context;
 
-	iwibdev = (struct i40iw_ib_device *)ib_alloc_device(sizeof(*iwibdev));
+	iwibdev = ib_alloc_device(i40iw_ib_device, ibdev);
 	if (!iwibdev) {
 		i40iw_pr_err("iwdev == NULL\n");
 		return NULL;

drivers/infiniband/hw/mlx4/main.c

@@ -2635,7 +2635,7 @@ static void *mlx4_ib_add(struct mlx4_dev *dev)
 	if (num_ports == 0)
 		return NULL;
 
-	ibdev = (struct mlx4_ib_dev *) ib_alloc_device(sizeof *ibdev);
+	ibdev = ib_alloc_device(mlx4_ib_dev, ib_dev);
 	if (!ibdev) {
 		dev_err(&dev->persist->pdev->dev,
 			"Device struct alloc failed\n");

drivers/infiniband/hw/mlx5/ib_rep.c

@@ -70,7 +70,7 @@ mlx5_ib_vport_rep_load(struct mlx5_core_dev *dev, struct mlx5_eswitch_rep *rep)
 {
 	struct mlx5_ib_dev *ibdev;
 
-	ibdev = (struct mlx5_ib_dev *)ib_alloc_device(sizeof(*ibdev));
+	ibdev = ib_alloc_device(mlx5_ib_dev, ib_dev);
 	if (!ibdev)
 		return -ENOMEM;
 

drivers/infiniband/hw/mlx5/main.c

@@ -6508,7 +6508,7 @@ static void *mlx5_ib_add(struct mlx5_core_dev *mdev)
 	if (mlx5_core_is_mp_slave(mdev) && ll == IB_LINK_LAYER_ETHERNET)
 		return mlx5_ib_add_slave_port(mdev);
 
-	dev = (struct mlx5_ib_dev *)ib_alloc_device(sizeof(*dev));
+	dev = ib_alloc_device(mlx5_ib_dev, ib_dev);
 	if (!dev)
 		return NULL;
 

drivers/infiniband/hw/mthca/mthca_main.c

@@ -961,7 +961,7 @@ static int __mthca_init_one(struct pci_dev *pdev, int hca_type)
 	/* We can handle large RDMA requests, so allow larger segments. */
 	dma_set_max_seg_size(&pdev->dev, 1024 * 1024 * 1024);
 
-	mdev = (struct mthca_dev *) ib_alloc_device(sizeof *mdev);
+	mdev = ib_alloc_device(mthca_dev, ib_dev);
 	if (!mdev) {
 		dev_err(&pdev->dev, "Device struct alloc failed, "
 			"aborting.\n");

drivers/infiniband/hw/nes/nes_verbs.c

@@ -3669,7 +3669,7 @@ struct nes_ib_device *nes_init_ofa_device(struct net_device *netdev)
 	struct nes_vnic *nesvnic = netdev_priv(netdev);
 	struct nes_device *nesdev = nesvnic->nesdev;
 
-	nesibdev = (struct nes_ib_device *)ib_alloc_device(sizeof(struct nes_ib_device));
+	nesibdev = ib_alloc_device(nes_ib_device, ibdev);
 	if (nesibdev == NULL) {
 		return NULL;
 	}

drivers/infiniband/hw/ocrdma/ocrdma_main.c

@@ -297,7 +297,7 @@ static struct ocrdma_dev *ocrdma_add(struct be_dev_info *dev_info)
 	u8 lstate = 0;
 	struct ocrdma_dev *dev;
 
-	dev = (struct ocrdma_dev *)ib_alloc_device(sizeof(struct ocrdma_dev));
+	dev = ib_alloc_device(ocrdma_dev, ibdev);
 	if (!dev) {
 		pr_err("Unable to allocate ib device\n");
 		return NULL;

drivers/infiniband/hw/qedr/main.c

@@ -853,7 +853,7 @@ static struct qedr_dev *qedr_add(struct qed_dev *cdev, struct pci_dev *pdev,
 	struct qedr_dev *dev;
 	int rc = 0;
 
-	dev = (struct qedr_dev *)ib_alloc_device(sizeof(*dev));
+	dev = ib_alloc_device(qedr_dev, ibdev);
 	if (!dev) {
 		pr_err("Unable to allocate ib device\n");
 		return NULL;

drivers/infiniband/hw/usnic/usnic_ib_main.c

@@ -372,7 +372,7 @@ static void *usnic_ib_device_add(struct pci_dev *dev)
 	usnic_dbg("\n");
 	netdev = pci_get_drvdata(dev);
 
-	us_ibdev = (struct usnic_ib_dev *)ib_alloc_device(sizeof(*us_ibdev));
+	us_ibdev = ib_alloc_device(usnic_ib_dev, ib_dev);
 	if (!us_ibdev) {
 		usnic_err("Device %s context alloc failed\n",
 				netdev_name(pci_get_drvdata(dev)));

drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c

@@ -795,7 +795,7 @@ static int pvrdma_pci_probe(struct pci_dev *pdev,
 	dev_dbg(&pdev->dev, "initializing driver %s\n", pci_name(pdev));
 
 	/* Allocate zero-out device */
-	dev = (struct pvrdma_dev *)ib_alloc_device(sizeof(*dev));
+	dev = ib_alloc_device(pvrdma_dev, ib_dev);
 	if (!dev) {
 		dev_err(&pdev->dev, "failed to allocate IB device\n");
 		return -ENOMEM;

drivers/infiniband/sw/rdmavt/vt.c

@@ -91,7 +91,7 @@ struct rvt_dev_info *rvt_alloc_device(size_t size, int nports)
 {
 	struct rvt_dev_info *rdi;
 
-	rdi = (struct rvt_dev_info *)ib_alloc_device(size);
+	rdi = container_of(_ib_alloc_device(size), struct rvt_dev_info, ibdev);
 	if (!rdi)
 		return rdi;
 

drivers/infiniband/sw/rxe/rxe_net.c

@@ -555,7 +555,7 @@ struct rxe_dev *rxe_net_add(struct net_device *ndev)
 	int err;
 	struct rxe_dev *rxe = NULL;
 
-	rxe = (struct rxe_dev *)ib_alloc_device(sizeof(*rxe));
+	rxe = ib_alloc_device(rxe_dev, ib_dev);
 	if (!rxe)
 		return NULL;
 

include/rdma/ib_verbs.h

@@ -2621,7 +2621,13 @@ struct ib_client {
 	struct list_head list;
 };
 
-struct ib_device *ib_alloc_device(size_t size);
+struct ib_device *_ib_alloc_device(size_t size);
+#define ib_alloc_device(drv_struct, member)                                    \
+	container_of(_ib_alloc_device(sizeof(struct drv_struct) +              \
+				      BUILD_BUG_ON_ZERO(offsetof(              \
+					      struct drv_struct, member))),    \
+		     struct drv_struct, member)
+
 void ib_dealloc_device(struct ib_device *device);
 
 void ib_get_device_fw_str(struct ib_device *device, char *str);