[PATCH net-next] net/fsl: xgmac_mdio: fix return value check in xgmac_mdio_probe()

[PATCH net-next] net/fsl: xgmac_mdio: fix return value check in xgmac_mdio_probe()

[Wei Yongjun]

In case of error, the function devm_ioremap() returns NULL pointer
not ERR_PTR(). The IS_ERR() test in the return value check should
be replaced with NULL test.

Fixes: 1d14eb15dc2c ("net/fsl: xgmac_mdio: Use managed device resources")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
---
 drivers/net/ethernet/freescale/xgmac_mdio.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/freescale/xgmac_mdio.c b/drivers/net/ethernet/freescale/xgmac_mdio.c
index d38d0c372585..264162049c6d 100644
--- a/drivers/net/ethernet/freescale/xgmac_mdio.c
+++ b/drivers/net/ethernet/freescale/xgmac_mdio.c
@@ -335,8 +335,8 @@ static int xgmac_mdio_probe(struct platform_device *pdev)
 	priv = bus->priv;
 	priv->mdio_base = devm_ioremap(&pdev->dev, res->start,
 				       resource_size(res));
-	if (IS_ERR(priv->mdio_base))
-		return PTR_ERR(priv->mdio_base);
+	if (!priv->mdio_base)
+		return -ENOMEM;
 
 	/* For both ACPI and DT cases, endianness of MDIO controller
 	 * needs to be specified using "little-endian" property.

Re: [PATCH net-next] net/fsl: xgmac_mdio: fix return value check in xgmac_mdio_probe()

[Tobias Waldekranz]

On Sat, Jan 29, 2022 at 01:27, Wei Yongjun <weiyongjun1@huawei.com> wrote:
> In case of error, the function devm_ioremap() returns NULL pointer
> not ERR_PTR(). The IS_ERR() test in the return value check should
> be replaced with NULL test.
>
> Fixes: 1d14eb15dc2c ("net/fsl: xgmac_mdio: Use managed device resources")
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>

Reviewed-by: Tobias Waldekranz <tobias@waldekranz.com>

Sorry about that. I started out by using devm_ioremap_resource, which
uses the in-band error signaling, and forgot to match the guard when I
changed it.

I see that this was reported by your CI, do you mind me asking what it
is running in the back-end? At least my version of sparse does not seem
to catch this.

Re: [PATCH net-next] net/fsl: xgmac_mdio: fix return value check in xgmac_mdio_probe()

[weiyongjun (A)]

> On Sat, Jan 29, 2022 at 01:27, Wei Yongjun <weiyongjun1@huawei.com> wrote:
>> In case of error, the function devm_ioremap() returns NULL pointer
>> not ERR_PTR(). The IS_ERR() test in the return value check should
>> be replaced with NULL test.
>>
>> Fixes: 1d14eb15dc2c ("net/fsl: xgmac_mdio: Use managed device resources")
>> Reported-by: Hulk Robot <hulkci@huawei.com>
>> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
> Reviewed-by: Tobias Waldekranz <tobias@waldekranz.com>
>
> Sorry about that. I started out by using devm_ioremap_resource, which
> uses the in-band error signaling, and forgot to match the guard when I
> changed it.
>
> I see that this was reported by your CI, do you mind me asking what it
> is running in the back-end? At least my version of sparse does not seem
> to catch this.


It was reported by coccinelle with follow script:


@@
expression ret, E;
@@
ret = \(devm_ioport_map\|
devm_ioremap\|
devm_ioremap_wc\|
devm_irq_alloc_generic_chip\|
devm_kasprintf\|
devm_kcalloc\|
devm_kmalloc\|
devm_kmalloc_array\|
devm_kmemdup\|
devm_kstrdup\|
devm_kzalloc\|
\)(...);
... when != ret = E
(
- IS_ERR(ret)
+ !ret
|
- !IS_ERR(ret)
+ ret
|
- PTR_ERR(ret)
+ -ENOMEM
)



It seems smatch also can report this.


Regards,

Wei Yongjun

Re: [PATCH net-next] net/fsl: xgmac_mdio: fix return value check in xgmac_mdio_probe()

[Dan Carpenter]

On Sun, Jan 30, 2022 at 08:58:55AM +0800, weiyongjun (A) wrote:
> 
> > On Sat, Jan 29, 2022 at 01:27, Wei Yongjun <weiyongjun1@huawei.com> wrote:
> > > In case of error, the function devm_ioremap() returns NULL pointer
> > > not ERR_PTR(). The IS_ERR() test in the return value check should
> > > be replaced with NULL test.
> > > 
> > > Fixes: 1d14eb15dc2c ("net/fsl: xgmac_mdio: Use managed device resources")
> > > Reported-by: Hulk Robot <hulkci@huawei.com>
> > > Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
> > Reviewed-by: Tobias Waldekranz <tobias@waldekranz.com>
> > 
> > Sorry about that. I started out by using devm_ioremap_resource, which
> > uses the in-band error signaling, and forgot to match the guard when I
> > changed it.
> > 
> > I see that this was reported by your CI, do you mind me asking what it
> > is running in the back-end? At least my version of sparse does not seem
> > to catch this.
> 
> 
> It was reported by coccinelle with follow script:
> 
> 
> @@
> expression ret, E;
> @@
> ret = \(devm_ioport_map\|
> devm_ioremap\|
> devm_ioremap_wc\|
> devm_irq_alloc_generic_chip\|
> devm_kasprintf\|
> devm_kcalloc\|
> devm_kmalloc\|
> devm_kmalloc_array\|
> devm_kmemdup\|
> devm_kstrdup\|
> devm_kzalloc\|
> \)(...);
> ... when != ret = E
> (
> - IS_ERR(ret)
> + !ret
> |
> - !IS_ERR(ret)
> + ret
> |
> - PTR_ERR(ret)
> + -ENOMEM
> )
> 
> 
> 
> It seems smatch also can report this.

Yeah.  I had this patch in my postponed messages but you beat me to
sending it.

The Smatch check for this requires you to have the cross function
database built.  I should update it to remove that requirement for
at least the common functions that you have listed.

regards,
dan carpenter

Re: [PATCH net-next] net/fsl: xgmac_mdio: fix return value check in xgmac_mdio_probe()

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (master)
by David S. Miller <davem@davemloft.net>:

On Sat, 29 Jan 2022 01:27:02 +0000 you wrote:
> In case of error, the function devm_ioremap() returns NULL pointer
> not ERR_PTR(). The IS_ERR() test in the return value check should
> be replaced with NULL test.
> 
> Fixes: 1d14eb15dc2c ("net/fsl: xgmac_mdio: Use managed device resources")
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
> 
> [...]

Here is the summary with links:
  - [net-next] net/fsl: xgmac_mdio: fix return value check in xgmac_mdio_probe()
    https://git.kernel.org/netdev/net-next/c/cc4598cf179f

You are awesome, thank you!
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