static int ovl_mmap(struct file *file, struct vm_area_struct *vma)
{
struct file *realfile = file->private_data;
const struct cred *old_cred;
int ret;
if (!realfile->f_op->mmap)
return -ENODEV;
if (WARN_ON(file != vma->vm_file))
return -EIO;
vma->vm_file = get_file(realfile);
old_cred = ovl_override_creds(file_inode(file)->i_sb);
ret = call_mmap(vma->vm_file, vma);
revert_creds(old_cred);
if (ret) {
/* Drop reference count from new vm_file value */
fput(realfile);
} else {
/* Drop reference count from previous vm_file value */
fput(file);
}
ovl_file_accessed(file);
return ret;
}
static int vgem_prime_mmap(struct drm_gem_object *obj,
struct vm_area_struct *vma)
{
int ret;
if (obj->size < vma->vm_end - vma->vm_start)
return -EINVAL;
if (!obj->filp)
return -ENODEV;
ret = call_mmap(obj->filp, vma);
if (ret)
return ret;
fput(vma->vm_file);
vma->vm_file = get_file(obj->filp);
vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
return 0;
}
