RDMA/erdma: use vmalloc_array and vcalloc

Use vmalloc_array and vcalloc to protect against
multiplication overflows.

The changes were done using the following Coccinelle
semantic patch:

// <smpl>
@initialize:ocaml@
@@

let rename alloc =
  match alloc with
    "vmalloc" -> "vmalloc_array"
  | "vzalloc" -> "vcalloc"
  | _ -> failwith "unknown"

@@
    size_t e1,e2;
    constant C1, C2;
    expression E1, E2, COUNT, x1, x2, x3;
    typedef u8;
    typedef __u8;
    type t = {u8,__u8,char,unsigned char};
    identifier alloc = {vmalloc,vzalloc};
    fresh identifier realloc = script:ocaml(alloc) { rename alloc };
@@

(
      alloc(x1*x2*x3)
|
      alloc(C1 * C2)
|
      alloc((sizeof(t)) * (COUNT), ...)
|
-     alloc((e1) * (e2))
+     realloc(e1, e2)
|
-     alloc((e1) * (COUNT))
+     realloc(COUNT, e1)
|
-     alloc((E1) * (E2))
+     realloc(E1, E2)
)
// </smpl>

Link: https://lore.kernel.org/r/20230627144339.144478-6-Julia.Lawall@inria.fr
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/erdma/erdma_verbs.c

@@ -481,8 +481,8 @@ static int init_kernel_qp(struct erdma_dev *dev, struct erdma_qp *qp,
 		dev->func_bar + (ERDMA_SDB_SHARED_PAGE_INDEX << PAGE_SHIFT);
 	kqp->hw_rq_db = dev->func_bar + ERDMA_BAR_RQDB_SPACE_OFFSET;
 
-	kqp->swr_tbl = vmalloc(qp->attrs.sq_size * sizeof(u64));
-	kqp->rwr_tbl = vmalloc(qp->attrs.rq_size * sizeof(u64));
+	kqp->swr_tbl = vmalloc_array(qp->attrs.sq_size, sizeof(u64));
+	kqp->rwr_tbl = vmalloc_array(qp->attrs.rq_size, sizeof(u64));
 	if (!kqp->swr_tbl || !kqp->rwr_tbl)
 		goto err_out;