On Tue, Sep 19, 2017 at 12:15:57PM -0400, Meng Xu wrote:

Hi Christoph,

By saying not copying the byte twice, did you mean
copy_from_user(req->cmd, sic->data + sizeof(opcode), cmdlen -
sizeof(opcode)) ?

Does it affect the how req->cmd will be used later?
If no, I'll submit another patch as instructed.

No, do something like:

	req->cmd[0] = opcode;
   	if (copy_from_user(req->cmd + 1, sic->data, cmdlen - 1))
   		goto error;