linux-kernel - [PATCH] Remove pointless NULL pointer check in drivers/usb/storage/shuttle

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Message-Id: <1189118009.19079.22.camel@odie.local>
Date:	Fri, 07 Sep 2007 00:33:29 +0200
From:	Simon Holm Thøgersen <odie@...aau.dk>
To:	Jens Axboe <jens.axboe@...cle.com>
Cc:	Micah Gruber <micah.gruber@...il.com>,
	linux-kernel@...r.kernel.org,
	linux-usb-devel@...ts.sourceforge.net, gregkh@...e.de
Subject: [PATCH] Remove pointless NULL pointer check in
	drivers/usb/storage/shuttle_usbat.c.

tir, 04 09 2007 kl. 23:06 +0200, skrev Jens Axboe:
> On Tue, Sep 04 2007, Simon Holm Thøgersen wrote:
> > tir, 04 09 2007 kl. 13:06 +0200, skrev Jens Axboe:
> > > On Tue, Sep 04 2007, Micah Gruber wrote:
> > > > This patch fixes a potential null dereference bug where we dereference us before a null check. This patch simply moves the dereferencing after the null check.
> > > > 
> > > > Signed-off-by: Micah Gruber <micah.gruber@...il.com>
> > > 
> > > Be careful with stuff like that, if you actually look at the code, a us
> > > == NULL doesn't seem to be possible (or usbat_flash_transport() would
> > > have oopsed before).
> > > 
> > If that is true, then
> >         if (!us)
> >                 return USB_STOR_TRANSPORT_ERROR;
> > is utterly pointless.
> 
> Well that was the point I was trying to make, that test and return
> should be deleted instead.
> 
I guess we agree that we want the following then.


If us would ever be NULL, the function would have oopsed already before
the check.

Signed-off-by: Simon Holm Thøgersen <odie@...aau.dk>
---

--- a/drivers/usb/storage/shuttle_usbat.c
+++ b/drivers/usb/storage/shuttle_usbat.c
@@ -190,9 +190,6 @@ static int usbat_check_status(struct us_data *us)
 	unsigned char *reply = us->iobuf;
 	int rc;
 
-	if (!us)
-		return USB_STOR_TRANSPORT_ERROR;
-
 	rc = usbat_get_status(us, reply);
 	if (rc != USB_STOR_XFER_GOOD)
 		return USB_STOR_TRANSPORT_FAILED;


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