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From:   Coiby Xu <coiby.xu@gmail.com>
Date:   Sat, 5 Sep 2020 00:03:08 +0800
To:     Benjamin Poirier <benjamin.poirier@gmail.com>
Cc:     devel@driverdev.osuosl.org, Manish Chopra <manishc@marvell.com>,
        "supporter:QLOGIC QLGE 10Gb ETHERNET DRIVER" 
        <GR-Linux-NIC-Dev@marvell.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Dan Carpenter <dan.carpenter@oracle.com>,
        "open list:QLOGIC QLGE 10Gb ETHERNET DRIVER" <netdev@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3] staging: qlge: fix build breakage with dumping enabled
Message-ID: <20200904160308.vpflvqfob7h7hz4v@Rk>
References: <20200902140031.203374-1-coiby.xu@gmail.com>
 <20200903034918.GA227281@f3>
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On Thu, Sep 03, 2020 at 12:49:18PM +0900, Benjamin Poirier wrote:
>On 2020-09-02 22:00 +0800, Coiby Xu wrote:
>> This fixes commit 0107635e15ac
>> ("staging: qlge: replace pr_err with netdev_err") which introduced an
>> build breakage of missing `struct ql_adapter *qdev` for some functions
>> and a warning of type mismatch with dumping enabled, i.e.,
>>
>> $ make CFLAGS_MODULE="QL_ALL_DUMP=1 QL_OB_DUMP=1 QL_CB_DUMP=1 \
>>   QL_IB_DUMP=1 QL_REG_DUMP=1 QL_DEV_DUMP=1" M=drivers/staging/qlge
>>
>> qlge_dbg.c: In function ‘ql_dump_ob_mac_rsp’:
>> qlge_dbg.c:2051:13: error: ‘qdev’ undeclared (first use in this function); did you mean ‘cdev’?
>>  2051 |  netdev_err(qdev->ndev, "%s\n", __func__);
>>       |             ^~~~
>> qlge_dbg.c: In function ‘ql_dump_routing_entries’:
>> qlge_dbg.c:1435:10: warning: format ‘%s’ expects argument of type ‘char *’, but argument 3 has type ‘int’ [-Wformat=]
>>  1435 |        "%s: Routing Mask %d = 0x%.08x\n",
>>       |         ~^
>>       |          |
>>       |          char *
>>       |         %d
>>  1436 |        i, value);
>>       |        ~
>>       |        |
>>       |        int
>> qlge_dbg.c:1435:37: warning: format ‘%x’ expects a matching ‘unsigned int’ argument [-Wformat=]
>>  1435 |        "%s: Routing Mask %d = 0x%.08x\n",
>>       |                                 ~~~~^
>>       |                                     |
>>       |                                     unsigned int
>>
>> Fixes: 0107635e15ac ("staging: qlge: replace pr_err with netdev_err")
>> Reported-by: Benjamin Poirier <benjamin.poirier@gmail.com>
>> Suggested-by: Benjamin Poirier <benjamin.poirier@gmail.com>
>> Signed-off-by: Coiby Xu <coiby.xu@gmail.com>
>> ---
>
>Thanks for following up on this issue.
>
>[...]
>> @@ -1632,8 +1635,8 @@ void ql_dump_wqicb(struct wqicb *wqicb)
>>
>>  void ql_dump_tx_ring(struct tx_ring *tx_ring)
>>  {
>> -	if (!tx_ring)
>> -		return;
>> +	struct ql_adapter *qdev = tx_ring->qdev;
>> +
>>  	netdev_err(qdev->ndev, "===================== Dumping tx_ring %d ===============\n",
>>  		   tx_ring->wq_id);
>>  	netdev_err(qdev->ndev, "tx_ring->base = %p\n", tx_ring->wq_base);
>
>Did you actually check to confirm that the test can be removed?

Thank you for the reminding! For the current code, when ql_dump_tx_ring
is called, tx_ring would never be null.

>
>This is something that you should mention in the changelog at the very
>least since that change is not directly about fixing the build breakage
>and if it's wrong, it can lead to null pointer deref.

I thought it is common practice in C that the caller makes sure
the passed parameter isn't a null pointer because a QEMU developer
also gave me the same advice after reviewing one of my patches for
QEMU a few weeks ago. I'll mention this in the commit message. Thank
you for the suggestion!


--
Best regards,
Coiby