Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <f05347d1-854c-4aa5-c937-71e7b36f234f@fujitsu.com>
Date:   Wed, 31 Aug 2022 11:02:35 +0800
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.11.0
Subject: Re: [PATCH] RDMA/srp: Set scmnd->result only when scmnd is not NULL
Content-Language: en-US
To:     =?UTF-8?B?WWFuZywgWGlhby/mnagg5pmT?= <yangx.jy@fujitsu.com>,
        "bvanassche@acm.org" <bvanassche@acm.org>,
        "jgg@nvidia.com" <jgg@nvidia.com>,
        "leon@kernel.org" <leon@kernel.org>
CC:     "linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
References: <20220831014730.17566-1-yangx.jy@fujitsu.com>
 <a66af10e-dea5-a9ec-5eeb-641b1d7ebeec@fujitsu.com>
 <e3488129-6681-55a7-3d1c-99a965a5c884@fujitsu.com>
From:   Li Zhijian <lizhijian@fujitsu.com>
In-Reply-To: <e3488129-6681-55a7-3d1c-99a965a5c884@fujitsu.com>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk


On 31/08/2022 10:31, Yang, Xiao/杨 晓 wrote:
> On 2022/8/31 9:59, Li Zhijian wrote:
>> What i can see is that we have other places to de-reference scmnd and
>>
>> scmnd = srp_claim_req(ch, req, NULL, scmnd) is possible to return a NULL
>> to scmnd
> Hi,
>
> Thanks for your review.
>
> Yes, it seems better to just check scmnd before setting scmnd->result,
> like this:
> diff --git a/drivers/infiniband/ulp/srp/ib_srp.c
> b/drivers/infiniband/ulp/srp/ib_srp.c
> index 7720ea270ed8..99f5e7f852b3 100644
> --- a/drivers/infiniband/ulp/srp/ib_srp.c
> +++ b/drivers/infiniband/ulp/srp/ib_srp.c
> @@ -1972,7 +1972,9 @@ static void srp_process_rsp(struct srp_rdma_ch
> *ch, struct srp_rsp *rsp)
>
>                           return;
>                   }
> -               scmnd->result = rsp->status;
> +
> +               if (scmnd)
> +                       scmnd->result = rsp->status;
Not really, i think you may need to return directly if !scmnd


>
> Best Regards,
> Xiao Yang