From: Dan Carpenter <dan.carpenter@oracle.com>
To: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Cc: Ian Cowan <ian@linux.cowan.aero>,
mripard@kernel.org, mchehab@kernel.org,
gregkh@linuxfoundation.org, wens@csie.org,
jernej.skrabec@gmail.com, samuel@sholland.org,
linux-media@vger.kernel.org, linux-staging@lists.linux.dev,
linux-arm-kernel@lists.infradead.org,
linux-sunxi@lists.linux.dev
Subject: Re: [PATCH] staging: sunxi: cedrus: centralize cedrus_open exit
Date: Thu, 28 Apr 2022 13:26:08 +0300 [thread overview]
Message-ID: <20220428102608.GU2462@kadam> (raw)
In-Reply-To: <Ymehl27gmW41a3FY@aptenodytes>
On Tue, Apr 26, 2022 at 09:39:03AM +0200, Paul Kocialkowski wrote:
>
> > Do-everything gotos are the most bug prone style of error handling.
> > Imagine the function is trying to do three things. It fails part way
> > through. Now you're trying to undo the second thing which was never
> > done. Just moments ago I was just looking at one of these do-everything
> > bugs where it was using uninitialized memory.
>
> So by that you mean having just one label for all error handling instead
> of labels for each undo step?
>
Yes. Don't do that. If you try to free everything, half the stuff is
not allocated so you will undo things which have not been done and it
leads to a bug.
> I've also seen conditionals used in error labels to undo stuff.
>
I don't understand what you're describing?
> Would you recommend duplicating error cleanup in each error condition?
> It feels like another set of issue on its own, besides the obvious downside
> of duplication.
Let me write a blog about it:
https://staticthinking.wordpress.com/2022/04/28/free-the-last-thing-style/
regards,
dan carpenter
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next prev parent reply other threads:[~2022-04-28 10:28 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-23 18:01 [PATCH] staging: sunxi: cedrus: centralize cedrus_open exit Ian Cowan
2022-04-25 9:20 ` Dan Carpenter
2022-04-25 9:29 ` Paul Kocialkowski
2022-04-25 10:00 ` Dan Carpenter
2022-04-26 7:39 ` Paul Kocialkowski
2022-04-28 10:26 ` Dan Carpenter [this message]
2022-04-28 11:56 ` Paul Kocialkowski
2022-04-25 9:36 ` Dan Carpenter
2022-04-25 15:52 ` Jernej Škrabec
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