(void __user *)arg这是什么意思?
static int nvme_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
unsigned long arg)
{
struct nvme_ns *ns = bdev->bd_disk->private_data;
switch (cmd) {
case NVME_IOCTL_ID:
return ns->ns_id;
case NVME_IOCTL_ADMIN_CMD:
return nvme_user_admin_cmd(ns, (void __user *)arg);
case NVME_IOCTL_SUBMIT_IO:
return nvme_submit_io(ns, (void __user *)arg);
default:
return -ENOTTY;
}
}
疑问:在上面的这个Linux块驱动ioctl代码中,(void __user *)arg是什么结构啊?_user是什么意思?没看明白,谢了!