2017-04-23 10:01:40

by Pan Bian

Subject: [PATCH 1/1] net: bcmgenet: fix incorrect return value checks

From: Pan Bian <[email protected]>

Function platform_get_irq() will return a negative value on errors.
However, in function bcmgenet_probe(), 0 is considered as a flag of
error. This patch fixes the bug by checking whether the return value of
platform_get_irq() is less than 0.

Signed-off-by: Pan Bian <[email protected]>
---
drivers/net/ethernet/broadcom/genet/bcmgenet.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index 365895e..0bccf2b 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -3329,7 +3329,7 @@ static int bcmgenet_probe(struct platform_device *pdev)
priv->irq0 = platform_get_irq(pdev, 0);
priv->irq1 = platform_get_irq(pdev, 1);
priv->wol_irq = platform_get_irq(pdev, 2);
- if (!priv->irq0 || !priv->irq1) {
+ if (priv->irq0 < 0 || priv->irq1 < 0) {
dev_err(&pdev->dev, "can't find IRQs\n");
err = -EINVAL;
goto err;
--
1.9.1

2017-04-24 19:48:20

by David Miller

Subject: Re: [PATCH 1/1] net: bcmgenet: fix incorrect return value checks

From: Pan Bian <[email protected]>
Date: Sun, 23 Apr 2017 18:01:05 +0800

> From: Pan Bian <[email protected]>
>
> Function platform_get_irq() will return a negative value on errors.
> However, in function bcmgenet_probe(), 0 is considered as a flag of
> error. This patch fixes the bug by checking whether the return value of
> platform_get_irq() is less than 0.
>
> Signed-off-by: Pan Bian <[email protected]>

I'm definitely not confident enough to apply this.

On some platform zero IRQs are invalid.

There are also lots of pieces of code that check the return value ">
0" as success.

2017-04-24 19:52:30

by Florian Fainelli

Subject: Re: [PATCH 1/1] net: bcmgenet: fix incorrect return value checks

On 04/24/2017 12:48 PM, David Miller wrote:
> From: Pan Bian <[email protected]>
> Date: Sun, 23 Apr 2017 18:01:05 +0800
>
>> From: Pan Bian <[email protected]>
>>
>> Function platform_get_irq() will return a negative value on errors.
>> However, in function bcmgenet_probe(), 0 is considered as a flag of
>> error. This patch fixes the bug by checking whether the return value of
>> platform_get_irq() is less than 0.
>>
>> Signed-off-by: Pan Bian <[email protected]>
>
> I'm definitely not confident enough to apply this.
>
> On some platform zero IRQs are invalid.
>
> There are also lots of pieces of code that check the return value ">
> 0" as success.
>

I don't think we are fixing any real issue by applying this patch, but I
will do a check on ARM, ARM64 and MIPS where this driver is used to see
if it is even remotely possible to have a 0 IRQ.
--
Florian