[PATCH] mt7601u: check memory allocation failure

[PATCH] mt7601u: check memory allocation failure

[Christophe JAILLET]

Check memory allocation failure and return -ENOMEM in such a case, as
already done a few lines below

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
 drivers/net/wireless/mediatek/mt7601u/dma.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/wireless/mediatek/mt7601u/dma.c b/drivers/net/wireless/mediatek/mt7601u/dma.c
index 660267b359e4..fa0173579d32 100644
--- a/drivers/net/wireless/mediatek/mt7601u/dma.c
+++ b/drivers/net/wireless/mediatek/mt7601u/dma.c
@@ -484,6 +484,8 @@ static int mt7601u_alloc_tx(struct mt7601u_dev *dev)
 
 	dev->tx_q = devm_kcalloc(dev->dev, __MT_EP_OUT_MAX,
 				 sizeof(*dev->tx_q), GFP_KERNEL);
+	if (!dev->tx_q)
+		return -ENOMEM;
 
 	for (i = 0; i < __MT_EP_OUT_MAX; i++)
 		if (mt7601u_alloc_tx_queue(dev, &dev->tx_q[i]))
-- 
2.11.0

Re: [PATCH] mt7601u: check memory allocation failure

[Jakub Kicinski]

On Mon, 21 Aug 2017 22:59:56 +0200, Christophe JAILLET wrote:
> Check memory allocation failure and return -ENOMEM in such a case, as
> already done a few lines below
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

Acked-by: Jakub Kicinski <kubakici@wp.pl>

Thanks!

Re: [PATCH] mt7601u: check memory allocation failure

[Jakub Kicinski]

On Mon, 21 Aug 2017 14:34:30 -0700, Jakub Kicinski wrote:
> On Mon, 21 Aug 2017 22:59:56 +0200, Christophe JAILLET wrote:
> > Check memory allocation failure and return -ENOMEM in such a case, as
> > already done a few lines below
> > 
> > Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>  
> 
> Acked-by: Jakub Kicinski <kubakici@wp.pl>

Wait, I take that back.  This code is a bit weird.  We would return an
error, then mt7601u_dma_init() will call mt7601u_free_tx_queue() which
doesn't check for tx_q = NULL condition.

Looks like mt7601u_free_tx() has to check for dev->tx_q = NULL and
return early if that's the case.  Or mt7601u_alloc_tx() should really
clean things up on it's own on failure.  Ugh.

Re: [PATCH] mt7601u: check memory allocation failure

[Christophe JAILLET]

Le 21/08/2017 à 23:41, Jakub Kicinski a écrit :
> On Mon, 21 Aug 2017 14:34:30 -0700, Jakub Kicinski wrote:
>> On Mon, 21 Aug 2017 22:59:56 +0200, Christophe JAILLET wrote:
>>> Check memory allocation failure and return -ENOMEM in such a case, as
>>> already done a few lines below
>>>
>>> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
>> Acked-by: Jakub Kicinski <kubakici@wp.pl>
> Wait, I take that back.  This code is a bit weird.  We would return an
> error, then mt7601u_dma_init() will call mt7601u_free_tx_queue() which
> doesn't check for tx_q = NULL condition.
>
> Looks like mt7601u_free_tx() has to check for dev->tx_q = NULL and
> return early if that's the case.  Or mt7601u_alloc_tx() should really
> clean things up on it's own on failure.  Ugh.
>
You are right. Thanks for the review.

I've sent a v2 which updates 'mt7601u_free_tx()'.
Doing so sounds more in line with the spirit of this code.

CJ