naota / abuse-kmod Goto Github PK

Hi naota!

This project is originated from ABUSE and later updated by you to use mq. Great work.

I tried to understand the code but I can't see how this module transfers write data to the userland.

In write, the user firstly GET request from the req_list. The write data has to be copied at this moment but there is no code in abuse_get_req to copy the bv_page from the internal request.

Somehow, the code exists in abuse_put_req but this function should be called when caller returns the result of write after doing some work in the userland.

		if (rq_data_dir(req->rq) != WRITE)
			ret = copy_from_user(kaddr + bvec.bv_offset,
					     (void __user *)ab->ab_xfer[i].ab_address,
					     bvec.bv_len);
		else // what does this branch mean?
			ret = copy_to_user((void __user *)ab->ab_xfer[i].ab_address,
					   kaddr + bvec.bv_offset, bvec.bv_len)