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Subject: Re: [PATCH RFC v2 0/6] staging: r8188eu: avoid uninit value bugs
To:     Larry.Finger@lwfinger.net, phil@philpotter.co.uk,
        gregkh@linuxfoundation.org, straube.linux@gmail.com,
        fmdefrancesco@gmail.com
Cc:     linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org
References: <6182ed46-d79d-7f66-c7c0-096486410b4d@gmail.com>
 <cover.1629642658.git.paskripkin@gmail.com>
From:   Pavel Skripkin <paskripkin@gmail.com>
Message-ID: <44fc34ec-6bbe-9cd0-0c51-78836bad7e0c@gmail.com>
Date:   Sun, 22 Aug 2021 18:30:09 +0300
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On 8/22/21 5:35 PM, Pavel Skripkin wrote:
> Hi, Greg, Larry and Phillip!
> 
> I noticed, that new staging driver was added like 3 weeks ago and I decided
> to look at the code, because drivers in staging directory are always buggy.
> 
> The first thing I noticed is *no one* was checking read operations result, but
> it can fail and driver may start writing random stack values into registers. It
> can cause driver misbehavior or device misbehavior.
> 
> To avoid this type of bugs, i've changed rtw_read* API. Now all rtw_read
> funtions return an error, when something went wrong with usb transfer.
> 
> It helps callers to break/return earlier and don't write random values to
> registers or to rely on random values.
> 
> Why is this pacth series RFC?
>    1. I don't have this device and I cannot test these changes.
>    2. I don't know how to handle errors in each particular case. For now, function
>       just returns or returns an error. That's all. I hope, driver maintainers will
>       help with these bits.
>    3. I guess, I handled not all uninit value bugs here. I hope, I fixed
>       at least half of them
> 
> 
> v1 -> v2:
>    1. Make rtw_read*() return an error instead of initializing pointer to error
>    2. Split one huge patch to smaller ones for each rtw_read{8,16,32} function
>       changes
>    3. Add new macro for printing register values (It helps to not copy-paste error
>       handling)
>    4. Removed {read,write}_macreg (Suggested by Phillip)
>    5. Rebased on top of staging-next
>    6. Cleaned checkpatch errors and warnings
> 
> Only build-tested, since I don't have device with r8118eu chip
> 

BTW, can you recommend any devices with this chip except for ASUS 
USB-N10 Nano? I didn't find any of them with delivery/reasonable 
delivery price to Russia.

I want to help with testing and moving this driver out of staging 
directory :)


With regards,
Pavel Skripkin