2016-12-19 06:19:57

by Christophe JAILLET

Subject: [RFC] Question about freeing of resource in 'atlas7_pinmux_probe()', in file 'drivers/pinctrl/sirf/pinctrl-atlas7.c'

Hi,

while playing with coccinelle, a missing 'of_node_put()' triggered in
'atlas7_pinmux_probe()', in file 'drivers/pinctrl/sirf/pinctrl-atlas7.c'.

/* The sd3 and sd9 shared all pins, and the function select by
* SYS2PCI_SDIO9SEL register
*/
sys2pci_np = of_find_node_by_name(NULL, "sys2pci");
if (!sys2pci_np)
return -EINVAL;
ret = of_address_to_resource(sys2pci_np, 0, &res);
if (ret) <------------- missing of_node_put(sys2pci_np);
return ret;
pmx->sys2pci_base = devm_ioremap_resource(&pdev->dev, &res);
if (IS_ERR(pmx->sys2pci_base)) {
of_node_put(sys2pci_np); <------------- added by commit
151b8c5ba1eb
return -ENOMEM;
}

Looking at the history of this file, I found a recent commit that added
another missing of_node_put (see above).


Adding missing 'of_node_put()' in error handling paths is fine, but in
this particular case, I was wondering if one was not also missing in the
normal path?


In such a case, I would revert 151b8c5ba1eb and propose something like:
/* The sd3 and sd9 shared all pins, and the function select by
* SYS2PCI_SDIO9SEL register
*/
sys2pci_np = of_find_node_by_name(NULL, "sys2pci");
if (!sys2pci_np)
return -EINVAL;
ret = of_address_to_resource(sys2pci_np, 0, &res);
if (ret) {
of_node_put(sys2pci_np);
return ret;
}
of_node_put(sys2pci_np);

pmx->sys2pci_base = devm_ioremap_resource(&pdev->dev, &res);
if (IS_ERR(pmx->sys2pci_base))
return -ENOMEM;

Thanks for your comment,

best regards,

CJ

2016-12-19 13:54:32

by Vladimir Zapolskiy

Subject: Re: [RFC] Question about freeing of resource in 'atlas7_pinmux_probe()', in file 'drivers/pinctrl/sirf/pinctrl-atlas7.c'

Hi,

On 12/19/2016 08:19 AM, Marion & Christophe JAILLET wrote:
> Hi,
>
> while playing with coccinelle, a missing 'of_node_put()' triggered in
> 'atlas7_pinmux_probe()', in file 'drivers/pinctrl/sirf/pinctrl-atlas7.c'.
>
> /* The sd3 and sd9 shared all pins, and the function select by
> * SYS2PCI_SDIO9SEL register
> */
> sys2pci_np = of_find_node_by_name(NULL, "sys2pci");
> if (!sys2pci_np)
> return -EINVAL;
> ret = of_address_to_resource(sys2pci_np, 0, &res);
> if (ret) <------------- missing of_node_put(sys2pci_np);
> return ret;
> pmx->sys2pci_base = devm_ioremap_resource(&pdev->dev, &res);
> if (IS_ERR(pmx->sys2pci_base)) {
> of_node_put(sys2pci_np); <------------- added by commit
> 151b8c5ba1eb
> return -ENOMEM;
> }
>
> Looking at the history of this file, I found a recent commit that added
> another missing of_node_put (see above).
>
>
> Adding missing 'of_node_put()' in error handling paths is fine, but in
> this particular case, I was wondering if one was not also missing in the
> normal path?

Right, in this particular case 'of_node_put()' should be both on error
and normal paths.

>
> In such a case, I would revert 151b8c5ba1eb and propose something like:
> /* The sd3 and sd9 shared all pins, and the function select by
> * SYS2PCI_SDIO9SEL register
> */
> sys2pci_np = of_find_node_by_name(NULL, "sys2pci");
> if (!sys2pci_np)
> return -EINVAL;
> ret = of_address_to_resource(sys2pci_np, 0, &res);
> if (ret) {
> of_node_put(sys2pci_np);
> return ret;
> }
> of_node_put(sys2pci_np);

Functionally it looks good, I have two comments though.

1) you don't need to revert 151b8c5ba1eb, the commit is a proper fix
per se but incomplete, please add your change on top of it,

2) minimizing the lines of code by removing duplicates is always good,
so here a better and complete fix will be like the following one:

sys2pci_np = of_find_node_by_name(NULL, "sys2pci");
if (!sys2pci_np)
return -EINVAL;

ret = of_address_to_resource(sys2pci_np, 0, &res);
of_node_put(sys2pci_np);
if (ret)
return ret;

pmx->sys2pci_base = devm_ioremap_resource(&pdev->dev, &res);
if (IS_ERR(pmx->sys2pci_base))
return -ENOMEM;

>
> pmx->sys2pci_base = devm_ioremap_resource(&pdev->dev, &res);
> if (IS_ERR(pmx->sys2pci_base))
> return -ENOMEM;

--
With best wishes,
Vladimir

2016-12-20 05:44:15

by Christophe JAILLET

Subject: Re: [RFC] Question about freeing of resource in 'atlas7_pinmux_probe()', in file 'drivers/pinctrl/sirf/pinctrl-atlas7.c'

Le 19/12/2016 à 14:54, Vladimir Zapolskiy a écrit :
> Functionally it looks good, I have two comments though.
> 1) you don't need to revert 151b8c5ba1eb, the commit is a proper fix
> per se but incomplete, please add your change on top of it,
>
> 2) minimizing the lines of code by removing duplicates is always good,
> so here a better and complete fix will be like the following one:
>
Hi,

thanks for the feedback and comments.
Patch submitted.

CJ