[PATCH] SLIP: simplify sl_free_bufs

[PATCH] SLIP: simplify sl_free_bufs

[Jesper Juhl]

We can avoid assignments to the local variable 'tmp' and 
actually get rid of tmp alltogether in sl_free_bufs(). This patch does 
that.  This is safe since both kfree() and slhc_free() handles NULL 
pointers gracefully.

A related question: Why the use of NULLSLCOMPR & NULLSLSTATE instead of 
plain NULL for struct slcompress and its members?
They are defined as 
	#define NULLSLCOMPR     (struct slcompress *)0
	#define NULLSLSTATE     (struct cstate *)0
Seems to me that plain NULL might as well be used (and if so I have a few 
more potential cleanups in the queue).


Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
---

 drivers/net/slip.c |   14 ++++----------
 1 files changed, 4 insertions(+), 10 deletions(-)

--- linux-2.6.12-rc6-orig/drivers/net/slip.c	2005-06-07 00:07:22.000000000 +0200
+++ linux-2.6.12-rc6-mm1/drivers/net/slip.c	2005-06-15 21:39:39.000000000 +0200
@@ -198,18 +198,12 @@ err_exit:
 static void
 sl_free_bufs(struct slip *sl)
 {
-	void * tmp;
-
 	/* Free all SLIP frame buffers. */
-	tmp = xchg(&sl->rbuff, NULL);
-	kfree(tmp);
-	tmp = xchg(&sl->xbuff, NULL);
-	kfree(tmp);
+	kfree(xchg(&sl->rbuff, NULL));
+	kfree(xchg(&sl->xbuff, NULL));
 #ifdef SL_INCLUDE_CSLIP
-	tmp = xchg(&sl->cbuff, NULL);
-	kfree(tmp);
-	if ((tmp = xchg(&sl->slcomp, NULL)) != NULL)
-		slhc_free(tmp);
+	kfree(xchg(&sl->cbuff, NULL));
+	slhc_free(xchg(&sl->slcomp, NULL));
 #endif
 }
 



Please CC me on replies.

-- 
Jesper Juhl

Re: [PATCH] SLIP: simplify sl_free_bufs

[Jesper Juhl]

The patch below still applies cleanly to 2.6.12 - any chance this might 
get applied? or any good reasons not to apply it?

-- Jesper


On Wed, 15 Jun 2005, Jesper Juhl wrote:

> We can avoid assignments to the local variable 'tmp' and 
> actually get rid of tmp alltogether in sl_free_bufs(). This patch does 
> that.  This is safe since both kfree() and slhc_free() handles NULL 
> pointers gracefully.
> 
> A related question: Why the use of NULLSLCOMPR & NULLSLSTATE instead of 
> plain NULL for struct slcompress and its members?
> They are defined as 
> 	#define NULLSLCOMPR     (struct slcompress *)0
> 	#define NULLSLSTATE     (struct cstate *)0
> Seems to me that plain NULL might as well be used (and if so I have a few 
> more potential cleanups in the queue).
> 
> 
> Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
> ---
> 
>  drivers/net/slip.c |   14 ++++----------
>  1 files changed, 4 insertions(+), 10 deletions(-)
> 
> --- linux-2.6.12-rc6-orig/drivers/net/slip.c	2005-06-07 00:07:22.000000000 +0200
> +++ linux-2.6.12-rc6-mm1/drivers/net/slip.c	2005-06-15 21:39:39.000000000 +0200
> @@ -198,18 +198,12 @@ err_exit:
>  static void
>  sl_free_bufs(struct slip *sl)
>  {
> -	void * tmp;
> -
>  	/* Free all SLIP frame buffers. */
> -	tmp = xchg(&sl->rbuff, NULL);
> -	kfree(tmp);
> -	tmp = xchg(&sl->xbuff, NULL);
> -	kfree(tmp);
> +	kfree(xchg(&sl->rbuff, NULL));
> +	kfree(xchg(&sl->xbuff, NULL));
>  #ifdef SL_INCLUDE_CSLIP
> -	tmp = xchg(&sl->cbuff, NULL);
> -	kfree(tmp);
> -	if ((tmp = xchg(&sl->slcomp, NULL)) != NULL)
> -		slhc_free(tmp);
> +	kfree(xchg(&sl->cbuff, NULL));
> +	slhc_free(xchg(&sl->slcomp, NULL));
>  #endif
>  }
>  
> 
> 
> 
> Please CC me on replies.
> 
> -- 
> Jesper Juhl
> 

Re: [PATCH] SLIP: simplify sl_free_bufs

[David S. Miller]

From: Jesper Juhl <juhl-lkml@dif.dk>
Date: Thu, 23 Jun 2005 22:46:06 +0200 (CEST)

> The patch below still applies cleanly to 2.6.12 - any chance this might 
> get applied? or any good reasons not to apply it?

I'll put it in my tree, give me a day or so.

Re: [PATCH] SLIP: simplify sl_free_bufs

[Jesper Juhl]

On 6/23/05, David S. Miller <davem@davemloft.net> wrote:
> From: Jesper Juhl <juhl-lkml@dif.dk>
> Date: Thu, 23 Jun 2005 22:46:06 +0200 (CEST)
> 
> > The patch below still applies cleanly to 2.6.12 - any chance this might
> > get applied? or any good reasons not to apply it?
> 
> I'll put it in my tree, 

Thanks.

>give me a day or so.
> 
No problem. :)


-- 
Jesper Juhl <jesper.juhl@gmail.com>
Don't top-post  http://www.catb.org/~esr/jargon/html/T/top-post.html
Plain text mails only, please      http://www.expita.com/nomime.html

Re: [PATCH] SLIP: simplify sl_free_bufs

[David S. Miller]

From: Jesper Juhl <juhl-lkml@dif.dk>
Date: Thu, 23 Jun 2005 22:46:06 +0200 (CEST)

> The patch below still applies cleanly to 2.6.12 - any chance this might 
> get applied? or any good reasons not to apply it?

Patch applied, thanks Jesper.