xen: use struct_size() helper in kzalloc()

struct privcmd_buf_vma_private has a zero-sized array at the end
(pages), use the new struct_size() helper to determine the proper
allocation size and avoid potential type mistakes.

Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

diff --git a/drivers/xen/privcmd-buf.c b/drivers/xen/privcmd-buf.c
index de01a6d0059dc4adcb98a24197750f72b0b4ceaf..a1c61e351d3f7ee5cb8e82ba4a391559e6a8aef2 100644 (file)
--- a/drivers/xen/privcmd-buf.c
+++ b/drivers/xen/privcmd-buf.c
@@ -140,8 +140,7 @@ static int privcmd_buf_mmap(struct file *file, struct vm_area_struct *vma)
        if (!(vma->vm_flags & VM_SHARED))
                return -EINVAL;
 
-       vma_priv = kzalloc(sizeof(*vma_priv) + count * sizeof(void *),
-                          GFP_KERNEL);
+       vma_priv = kzalloc(struct_size(vma_priv, pages, count), GFP_KERNEL);
        if (!vma_priv)
                return -ENOMEM;