Re: usb/net/rt2x00: warning in rt2800_eeprom_word_index

From: Dmitry Vyukov
Date: Mon Oct 16 2017 - 08:17:20 EST


On Mon, Oct 16, 2017 at 12:27 PM, Kalle Valo <kvalo@xxxxxxxxxxxxxx> wrote:
> Dmitry Vyukov <dvyukov@xxxxxxxxxx> writes:
>
>> On Thu, Oct 12, 2017 at 9:25 AM, Stanislaw Gruszka <sgruszka@xxxxxxxxxx> wrote:
>>> Hi
>>>
>>> On Mon, Oct 09, 2017 at 07:50:53PM +0200, Andrey Konovalov wrote:
>>>> I've got the following report while fuzzing the kernel with syzkaller.
>>>>
>>>> On commit 8a5776a5f49812d29fe4b2d0a2d71675c3facf3f (4.14-rc4).
>>>>
>>>> I'm not sure whether this is a bug in the driver, or just a way to
>>>> report misbehaving device. In the latter case this shouldn't be a
>>>> WARN() call, since WARN() means bug in the kernel.
>>>
>>> This is about wrong EEPROM, which reported 3 tx streams on
>>> non 3 antenna device. I think WARN() is justified and thanks
>>> to the call trace I was actually able to to understand what
>>> happened.
>>>
>>> In general I do not think WARN() only means a kernel bug, it
>>> can be F/W or H/W bug too.
>>
>> Hi Stanislaw,
>>
>> Printing messages is fine. Printing stacks is fine. Just please make
>> them distinguishable from kernel bugs and don't kill the whole
>> possibility of automated Linux kernel testing. That's an important
>> capability.
>
> Not really following you. Are you saying that using WARN() prevents
> automated Linux kernel testing?


Absence of a way to understand when there is something wrong with
kernel (something to notify kernel developers about) is the problem.