Re: [bug report] RDMA/erdma: Add verbs implementation

[Cheng Xu <chengyou@linux.alibaba.com>]

On 6/8/22 8:56 PM, Dan Carpenter wrote:
> Hello Cheng Xu,
> 
> The patch c4612e83c14b: "RDMA/erdma: Add verbs implementation" from
> May 23, 2022, leads to the following Smatch static checker warning:
> 
> 	drivers/infiniband/hw/erdma/erdma_verbs.c:111 create_qp_cmd()
> 	error: uninitialized symbol 'resp0'.
> 
> drivers/infiniband/hw/erdma/erdma_verbs.c
>      100                 req.sq_buf_addr = user_qp->sq_mtt.mtt_entry[0];
>      101                 req.rq_buf_addr = user_qp->rq_mtt.mtt_entry[0];
>      102
>      103                 req.sq_db_info_dma_addr = user_qp->sq_db_info_dma_addr;
>      104                 req.rq_db_info_dma_addr = user_qp->rq_db_info_dma_addr;
>      105         }
>      106
>      107         err = erdma_post_cmd_wait(&dev->cmdq, (u64 *)&req, sizeof(req), &resp0,
>      108                                   &resp1);
> 
> The erdma_post_cmd_wait() function does not initialize erdma_post_cmd_wait()
> on the error paths.

Oh, I knew this before: since erdma_post_cmd_wait returns error, the qp
's resource will destroy soon, the uninitialized value of resp0 will
influence nothing. So here I reduce a condition judgement.

Anyway, I will fix it to eliminate the static checker warning.


> Also it returns comp_wait->comp_status which is a u8.  I guess that's
> some kind of custom error code.  Mixing kernel and custom error codes
> is dangerous.  I think it's a bug in this case.
> 

I will fix it in the next version of our patches.

Thanks,
Cheng Xu