Subject: Re: [PATCH] staging: unisys: use common return path
To: Dan Carpenter <dan.carpenter@oracle.com>
References: <1448950555-8846-1-git-send-email-sudipm.mukherjee@gmail.com>
 <20151201080045.GE18797@mwanda> <565DB4BA.80208@unisys.com>
 <20151201155724.GG18797@mwanda>
CC: Sudip Mukherjee <sudipm.mukherjee@gmail.com>, <devel@driverdev.osuosl.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        <sparmaintainer@unisys.com>, <linux-kernel@vger.kernel.org>
From: Ben Romer <benjamin.romer@unisys.com>
Message-ID: <565DC7D0.3000307@unisys.com>
Date: Tue, 1 Dec 2015 11:16:16 -0500
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On 12/01/2015 10:57 AM, Dan Carpenter wrote:
> What I meant was that I'm generally opposed to "common exit paths".
> Mixing all the exit paths together often makes the code more complicated
> and leads to errors.  That makes sense from a common sense perspective
> that doing many things is more difficult than doing one thing?  Anyway
> it's easy enough to verify empirically that this style is bug prone.
>
> On the other hand there are times where all exit paths need to unlock or
> to free a variable and in those cases using a common exit path makes
> sense.  Just don't standardize on "Every function should only have a
> single return".
>

That works for me. Mainly my issue with it is that I've spent a lot of 
time trying to eliminate "goto Away" code from the drivers, so I'd 
rather not put any back if possible.

>>
>> If we *have* to change it
>
> I don't think we have to change it at all.  Using direct returns makes
> finding locking bugs easier for static checkers.
>

That's true, and I think the code is fine as it is.

>> 		spin_unlock_irqrestore(&devdata->priv_lock, flags);
>
> This is a bug.
>

Indeed, but I'd rather not have any of these changes made anyway. This 
function isn't broken so it doesn't need to be fixed.

-- Ben
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