[dpdk-dev] [PATCH] net/szedata2: fix incorrect device memory access

[Matej Vido]

On 24.01.2017 16:11, Ferruh Yigit wrote:
> On 1/24/2017 2:02 PM, Matej Vido wrote:
>> On 24.01.2017 12:58, Ferruh Yigit wrote:
>>> On 1/24/2017 10:49 AM, Matej Vido wrote:
>>>> Fixes: 8acba705b119 ("net/szedata2: localize handling of PCI resources")
>>>>
>>>> Signed-off-by: Matej Vido <vido at cesnet.cz>
>>> Unrelated from this patch, in maintainers file, you have your other mail
>>> address: "Matej Vido <matejvido at gmail.com>", do you want to update it?
>> Hi Ferruh,
>>
>> yes, I will send the patch.
>>>> ---
>>>>    drivers/net/szedata2/rte_eth_szedata2.h | 2 +-
>>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/net/szedata2/rte_eth_szedata2.h b/drivers/net/szedata2/rte_eth_szedata2.h
>>>> index b58adb6..afe8a38 100644
>>>> --- a/drivers/net/szedata2/rte_eth_szedata2.h
>>>> +++ b/drivers/net/szedata2/rte_eth_szedata2.h
>>>> @@ -192,7 +192,7 @@ struct szedata {
>>>>    }
>>>>    
>>>>    #define SZEDATA2_PCI_RESOURCE_PTR(rsc, offset, type) \
>>>> -	((type)((uint8_t *)(rsc)->addr) + (offset))
>>>> +	((type)(((uint8_t *)(rsc)->addr) + (offset)))
>>> Although output will be same, (in all uses, type is a pointer),
> Of course won't be same, please forget about it J, I am confused.
>
> So these two differs a lot, taking into account that offset numbers used
> are big numbers (0x8000..), it should be accessing very unrelated addresses.
>
> So how this was working before?

The macro was fine before the patch [1]. It hasn't been working since 
the acceptance of that patch, but I didn't manage to test the 
functionality until now.

[1] http://dpdk.org/ml/archives/dev/2016-December/053241.html

Regards,
Matej

>
>> this
>>> seems the intention, so:
>>>
>>> Reviewed-by: Ferruh Yigit <ferruh.yigit at intel.com>
>>>
>>> btw, following will do same, right, not sure if it is better:
>>> ((type)(rsc)->addr + (offset))
>> This is also wrong. The intention of the macro is to add an offset to
>> the base address and typecast the result.
>>
>> Regards,
>> Matej
>>>>    
>>>>    enum szedata2_link_speed {
>>>>    	SZEDATA2_LINK_SPEED_DEFAULT = 0,
>>>>