On 06/05/2016 07:54 PM, Sudip Mukherjee wrote: > On Friday 03 June 2016 09:29 AM, Krzysztof Opasiak wrote: >> >> >> On 06/02/2016 03:22 PM, Sudip Mukherjee wrote: >>> We have been dereferencing udc before checking it. Lets use it after it >>> has been checked. >>> >> >> To be honest I have mixed feelings about this patch. >> >> On one hand it prevents us from dereferencing potential NULL ptr what is >> generally good. But on the other hand it seems to be a little bit >> pointless overhead. This function is called only in one place, it's >> internal function of vudc driver and in addition generally it is >> currently impossible that this function will get NULL ptr as parameter >> as it's value is taken from container_of(). Not to mention that if this >> is NULL or garbage we will end up in NULL ptr dereference much earlier >> before calling this function. >> >> So if there is something that you would like to fix with this patch and >> you have a real problem with this function could you please provide us >> some more details (for example stack trace)? If this patch is just to >> prevent us from something that will never happen then I would rather to >> not submit this. In my opinion if we get a NULL in this function this >> means that we have some serious problem in UDC core and this check will >> just mask this error. > > Yes, I should have seen earlier that the only caller has already > dereferenced udc. So maybe the following will be appropriate in this > situation. > Your patch does exactly what Alan suggested and I agree with it;) Could you please resend this properly so Greg can easily pick it up? Best regards, -- Krzysztof Opasiak Samsung R&D Institute Poland Samsung Electronics -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
