Coccinelle Archive on lore.kernel.org
 help / color / Atom feed
From: Markus Elfring <Markus.Elfring@web.de>
To: Wen Yang <yellowriver2010@hotmail.com>,
	Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Michal Marek <michal.lkml@markovi.net>,
	kernel-janitors@vger.kernel.org,
	Nicolas Palix <nicolas.palix@imag.fr>,
	LKML <linux-kernel@vger.kernel.org>,
	Coccinelle <cocci@systeme.lip6.fr>,
	Cheng Shengyu <cheng.shengyu@zte.com.cn>,
	Wen Yang <wen.yang99@zte.com.cn>
Subject: Re: [Cocci] [PATCH v6] coccinelle: semantic code search for missing put_device()
Date: Sun, 17 Feb 2019 10:50:05 +0100
Message-ID: <8e7ba7c0-b7fe-a1f0-d28b-0c716ecbcfdb@web.de> (raw)
In-Reply-To: <HK0PR02MB36344E2B29CEB195892F6420B2610@HK0PR02MB3634.apcprd02.prod.outlook.com>

> +@search exists@
> +local idexpression id;
> +expression x,e,e1;
> +position p1,p2;
> +type T,T1,T2;
> +@@
> +
> +id = of_find_device_by_node@p1(x)
> +... when != e = id

I suggest to increase your software development attention also for
another implementation detail.
Source code analysis triggers challenges for safe data flow handling.
the semantic patch language supports search specifications for
the exclusion of specific assignments.

Does this SmPL code contain a questionable order for the source
and target metavariables?
Can the following variant be more appropriate?

+ ... when != id = e


> +if (id == NULL || ...) { ... return ...; }
> +... when != put_device(&id->dev)
> +    when != platform_device_put(id)
> +    when != of_dev_put(id)
> +    when != if (id) { ... put_device(&id->dev) ... }
> +    when != e1 = (T)id

Would you like to avoid that the return value from the shown function call
gets overwritten in the variable before it was used once at least
(when a bit of extra C code is tolerated before a null pointer check)?

Regards,
Markus
_______________________________________________
Cocci mailing list
Cocci@systeme.lip6.fr
https://systeme.lip6.fr/mailman/listinfo/cocci

  parent reply index

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-16 16:05 Wen Yang
2019-02-16 16:33 ` Julia Lawall
2019-02-16 18:39 ` [Cocci] [v6] " Markus Elfring
2019-02-17  2:32   ` [Cocci] 答复: " Wen Yang
2019-02-17  7:42     ` Markus Elfring
2019-02-17  9:50 ` Markus Elfring [this message]
2019-02-17 11:37   ` [Cocci] [PATCH v6] " Julia Lawall
2019-02-17 11:42     ` Markus Elfring
2019-02-17 11:48       ` Julia Lawall
2019-02-17 12:00         ` [Cocci] [v6] " Markus Elfring
2019-02-17 12:05           ` Julia Lawall
2019-02-17 12:20             ` Markus Elfring
2019-02-17 12:52               ` Julia Lawall
2019-02-17 13:14                 ` Markus Elfring
2019-02-18  3:22                   ` wen.yang99
2019-02-18  6:43                     ` Julia Lawall
2019-02-18  8:19                       ` Markus Elfring
2019-02-19  2:14                         ` wen.yang99
2019-02-19  7:04                           ` Julia Lawall
2019-02-19  8:12                             ` Markus Elfring
2019-02-19  8:29                           ` Markus Elfring
2019-02-19  9:09                             ` wen.yang99
2019-02-19  9:30                               ` Markus Elfring
2019-03-06 11:18                           ` Markus Elfring
2019-02-18 21:40                     ` Markus Elfring

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=8e7ba7c0-b7fe-a1f0-d28b-0c716ecbcfdb@web.de \
    --to=markus.elfring@web.de \
    --cc=Julia.Lawall@lip6.fr \
    --cc=cheng.shengyu@zte.com.cn \
    --cc=cocci@systeme.lip6.fr \
    --cc=kernel-janitors@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=michal.lkml@markovi.net \
    --cc=nicolas.palix@imag.fr \
    --cc=wen.yang99@zte.com.cn \
    --cc=yellowriver2010@hotmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Coccinelle Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/cocci/0 cocci/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 cocci cocci/ https://lore.kernel.org/cocci \
		cocci@systeme.lip6.fr
	public-inbox-index cocci

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/fr.lip6.systeme.cocci


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git