2017-08-21 21:00:06

by Christophe JAILLET

Subject: [PATCH] mt7601u: check memory allocation failure

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

Signed-off-by: Christophe JAILLET <[email protected]>
---
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

2017-08-21 21:41:43

by Jakub Kicinski

Subject: Re: [PATCH] mt7601u: check memory allocation failure

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 <[email protected]>
>
> Acked-by: Jakub Kicinski <[email protected]>

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.

2017-08-21 22:08:58

by Christophe JAILLET

Subject: Re: [PATCH] mt7601u: check memory allocation failure

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 <[email protected]>
>> Acked-by: Jakub Kicinski <[email protected]>
> 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

2017-08-21 21:41:17

by Jakub Kicinski

Subject: Re: [PATCH] mt7601u: check memory allocation failure

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 <[email protected]>

Acked-by: Jakub Kicinski <[email protected]>

Thanks!