From mboxrd@z Thu Jan  1 00:00:00 1970
From: walter harms <wharms@bfs.de>
Date: Fri, 14 Sep 2012 14:44:25 +0000
Subject: Re: [PATCH v2 5/9] drivers/staging/gdm72xx/gdm_sdio.c: Remove useless kfree
Message-Id: <505342C9.30609@bfs.de>
List-Id: <kernel-janitors.vger.kernel.org>
References: <1347610518-3099-1-git-send-email-peter.senna@gmail.com>
In-Reply-To: <1347610518-3099-1-git-send-email-peter.senna@gmail.com>
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To: Peter Senna Tschudin <peter.senna@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, kernel-janitors@vger.kernel.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org



Am 14.09.2012 10:15, schrieb Peter Senna Tschudin:
> From: Peter Senna Tschudin <peter.senna@gmail.com>
> 
> Remove useless kfree() and clean up code related to the removal.
> 
> The semantic patch that finds this problem is as follows:
> (http://coccinelle.lip6.fr/)
> 
> // <smpl>
> @r exists@
> position p1,p2;
> expression x;
> @@
> 
> if (x@p1 = NULL) { ... kfree@p2(x); ... return ...; }
> 
> @unchanged exists@
> position r.p1,r.p2;
> expression e <= r.x,x,e1;
> iterator I;
> statement S;
> @@
> 
> if (x@p1 = NULL) { ... when != I(x,...) S
>                         when != e = e1
>                         when != e += e1
>                         when != e -= e1
>                         when != ++e
>                         when != --e
>                         when != e++
>                         when != e--
>                         when != &e
>    kfree@p2(x); ... return ...; }
> 
> @ok depends on unchanged exists@
> position any r.p1;
> position r.p2;
> expression x;
> @@
> 
> ... when != true x@p1 = NULL
> kfree@p2(x);
> 
> @depends on !ok && unchanged@
> position r.p2;
> expression x;
> @@
> 
> *kfree@p2(x);
> // </smpl>
> 
> Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
> 
> ---
>  drivers/staging/gdm72xx/gdm_sdio.c |   11 +++--------
>  1 file changed, 3 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/staging/gdm72xx/gdm_sdio.c b/drivers/staging/gdm72xx/gdm_sdio.c
> index f824290..f13dcbf 100644
> --- a/drivers/staging/gdm72xx/gdm_sdio.c
> +++ b/drivers/staging/gdm72xx/gdm_sdio.c
> @@ -93,18 +93,13 @@ static struct sdio_rx *alloc_rx_struct(struct rx_cxt *rx)
>  {
>  	struct sdio_rx *r = NULL;
>  
This is nice but just one thing:
you can also remove this = NULL  here.

re,
 wh


> -	r = kmalloc(sizeof(*r), GFP_ATOMIC);
> -	if (r = NULL)
> -		goto out;
> -
> -	memset(r, 0, sizeof(*r));
> +	r = kzalloc(sizeof(*r), GFP_ATOMIC);
> +	if (!r)
> +		return NULL;
>  
>  	r->rx_cxt = rx;
>  
>  	return r;
> -out:
> -	kfree(r);
> -	return NULL;
>  }
>  
>  static void free_rx_struct(struct sdio_rx *r)
> 
> 
>