Re: Coccinelle: semantic patch for missing of_node_put

From: Markus Elfring <Markus.Elfring@web.de>
To: Wen Yang <wen.yang99@zte.com.cn>, cocci@systeme.lip6.fr
Cc: linux-kernel@vger.kernel.org,
	Gilles Muller <Gilles.Muller@lip6.fr>,
	Julia Lawall <julia.lawall@lip6.fr>,
	Masahiro Yamada <yamada.masahiro@socionext.com>,
	Michal Marek <michal.lkml@markovi.net>,
	Nicolas Palix <nicolas.palix@imag.fr>,
	Yi Wang <wang.yi59@zte.com.cn>
Subject: Re: Coccinelle: semantic patch for missing of_node_put
Date: Thu, 9 May 2019 10:10:46 +0200	[thread overview]
Message-ID: <141163ed-a78b-6d89-e6cd-3442adda7073@web.de> (raw)
In-Reply-To: <201905090947015772925@zte.com.cn>

> It's interesting to get the function list automatically.

I occasionally imported code data into list variables
or even database tables.

> I'll try to parse the drivers/of/base.c file based on comments like this
> "* Returns a node pointer with refcount incremented, use
> * of_node_put() on it when done."
> to automatically get the name of the function that needs to be checked.

Will feature requests like the following become more interesting?

* Advanced data processing for source code comments
  https://github.com/coccinelle/coccinelle/issues/57

* Add a metavariable for the handling of source code
  https://github.com/coccinelle/coccinelle/issues/140

> We will continue to analyze the code of coccinelle

How will the understanding evolve for the OCaml source code
of this software?

> to confirm whether this false positive is a bug in coccinelle.

I am also curious on how the corresponding clarification will be continued.

By the way:
Yesterday I stumbled on another questionable software behaviour
while trying to apply an update suggestion from our development discussion
on the topic “[v6] coccinelle: semantic code search for missing put_device()”.
https://lore.kernel.org/cocci/201902191014156680299@zte.com.cn/
https://systeme.lip6.fr/pipermail/cocci/2019-February/005620.html

> But this statement is currently needed here.

Will the need be reconsidered?

I got another development concern here:
You propose to use a SmPL conjunction in the rule “r1”.
How does it fit to the previous exclusion specification “when != of_node_put(x)”?

Regards,
Markus