mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Julia Lawall <julia@diku.dk>
To: Oliver Neukum <oliver@neukum.org>
Cc: zaitcev@redhat.com, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [PATCH retry] drivers/usb/class/usblp.c: adjust error handling code
Date: Wed, 16 Jul 2008 18:00:42 +0200 (CEST)	[thread overview]
Message-ID: <Pine.LNX.4.64.0807161758520.28783@ask.diku.dk> (raw)
In-Reply-To: <200807161744.59137.oliver@neukum.org>

From: Julia Lawall <julia@diku.dk>

In this code, it is possible to tell statically whether usblp will be NULL
in the error handling code.

Oliver Neukum suggested to make a goto to the final return rather than 
return directly.

The semantic match that finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
identifier f,err,l,l1;
type T;
expression x,E;
statement S;
@@

x = NULL
... when != goto l1;
* x = f(...)
... when != x
err = E;
goto l;
...
* if (x != NULL)
  S
return err;
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>

---
diff -u -p a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c
--- a/drivers/usb/class/usblp.c
+++ b/drivers/usb/class/usblp.c
@@ -1076,15 +1076,16 @@ static int usblp_probe(struct usb_interf
 		       const struct usb_device_id *id)
 {
 	struct usb_device *dev = interface_to_usbdev (intf);
-	struct usblp *usblp = NULL;
+	struct usblp *usblp;
 	int protocol;
 	int retval;
 
 	/* Malloc and start initializing usblp structure so we can use it
 	 * directly. */
-	if (!(usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL))) {
+	usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL);
+	if (!usblp) {
 		retval = -ENOMEM;
-		goto abort;
+		goto abort_ret;
 	}
 	usblp->dev = dev;
 	mutex_init(&usblp->wmut);
@@ -1179,12 +1180,11 @@ abort_intfdata:
 	usb_set_intfdata (intf, NULL);
 	device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
 abort:
-	if (usblp) {
-		kfree(usblp->readbuf);
-		kfree(usblp->statusbuf);
-		kfree(usblp->device_id_string);
-		kfree(usblp);
-	}
+	kfree(usblp->readbuf);
+	kfree(usblp->statusbuf);
+	kfree(usblp->device_id_string);
+	kfree(usblp);
+abort_ret:
 	return retval;
 }
 

  reply	other threads:[~2008-07-16 16:00 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-07-16 15:17 [PATCH] " Julia Lawall
2008-07-16 15:44 ` Oliver Neukum
2008-07-16 16:00   ` Julia Lawall [this message]
2008-07-16 16:44 ` Pete Zaitcev

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=Pine.LNX.4.64.0807161758520.28783@ask.diku.dk \
    --to=julia@diku.dk \
    --cc=kernel-janitors@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=oliver@neukum.org \
    --cc=zaitcev@redhat.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
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®