The of_find_device_by_node() takes a reference to the underlying device
structure, we should release that reference.
Signed-off-by: Huang Zijiang <[email protected]>
---
drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c
index 14d7ec7..697d929 100644
--- a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c
+++ b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c
@@ -3081,6 +3081,7 @@ int hns_dsaf_roce_reset(struct fwnode_handle *dsaf_fwnode, bool dereset)
dsaf_dev = dev_get_drvdata(&pdev->dev);
if (!dsaf_dev) {
dev_err(&pdev->dev, "dsaf_dev is NULL\n");
+ put_device(&pdev->dev);
return -ENODEV;
}
@@ -3088,6 +3089,7 @@ int hns_dsaf_roce_reset(struct fwnode_handle *dsaf_fwnode, bool dereset)
if (AE_IS_VER1(dsaf_dev->dsaf_ver)) {
dev_err(dsaf_dev->dev, "%s v1 chip doesn't support RoCE!\n",
dsaf_dev->ae_dev.name);
+ put_device(&pdev->dev);
return -ENODEV;
}
--
1.8.3.1
From: Huang Zijiang <[email protected]>
Date: Thu, 14 Feb 2019 14:41:45 +0800
> The of_find_device_by_node() takes a reference to the underlying device
> structure, we should release that reference.
>
> Signed-off-by: Huang Zijiang <[email protected]>
Applied, thank you.
On 14/02/2019 06:41, Huang Zijiang wrote:
> The of_find_device_by_node() takes a reference to the underlying device
> structure, we should release that reference.
of_find_device_by_node() is not called for every path, so is this change
proper:
/* find the platform device corresponding to fwnode */
if (is_of_node(dsaf_fwnode)) {
pdev = of_find_device_by_node(to_of_node(dsaf_fwnode));
} else if (is_acpi_device_node(dsaf_fwnode)) {
pdev = hns_dsaf_find_platform_device(dsaf_fwnode);
} else {
pr_err("fwnode is neither OF or ACPI type\n");
return -EINVAL;
}
/* check if we were a success in fetching pdev */
if (!pdev) {
pr_err("couldn't find platform device for node\n");
return -ENODEV;
}
/* retrieve the dsaf_device from the driver data */
dsaf_dev = dev_get_drvdata(&pdev->dev);
if (!dsaf_dev) {
dev_err(&pdev->dev, "dsaf_dev is NULL\n");
return -ENODEV;
}
John
>
> Signed-off-by: Huang Zijiang <[email protected]>
> ---
> drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c
> index 14d7ec7..697d929 100644
> --- a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c
> +++ b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c
> @@ -3081,6 +3081,7 @@ int hns_dsaf_roce_reset(struct fwnode_handle *dsaf_fwnode, bool dereset)
> dsaf_dev = dev_get_drvdata(&pdev->dev);
> if (!dsaf_dev) {
> dev_err(&pdev->dev, "dsaf_dev is NULL\n");
> + put_device(&pdev->dev);
> return -ENODEV;
> }
>
> @@ -3088,6 +3089,7 @@ int hns_dsaf_roce_reset(struct fwnode_handle *dsaf_fwnode, bool dereset)
> if (AE_IS_VER1(dsaf_dev->dsaf_ver)) {
> dev_err(dsaf_dev->dev, "%s v1 chip doesn't support RoCE!\n",
> dsaf_dev->ae_dev.name);
> + put_device(&pdev->dev);
> return -ENODEV;
> }
>
>
> From: John Garry
> Sent: Friday, February 15, 2019 10:52 AM
>
> On 14/02/2019 06:41, Huang Zijiang wrote:
> > The of_find_device_by_node() takes a reference to the underlying device
> > structure, we should release that reference.
>
> of_find_device_by_node() is not called for every path, so is this change proper:
It looks okay to me and with the suggested device reference is being
released from every possible error leg in the function. Could you be
more specific which error path is not being addressed?
> /* find the platform device corresponding to fwnode */
> if (is_of_node(dsaf_fwnode)) {
> pdev = of_find_device_by_node(to_of_node(dsaf_fwnode));
This will get the reference to the device, which needs to be
released later.
> } else if (is_acpi_device_node(dsaf_fwnode)) {
> pdev = hns_dsaf_find_platform_device(dsaf_fwnode);
This will also get the reference to the device when bus_find_device()
gets called and returns the 'device'. Therefore, this needs to be
released as well using put_device()
> } else {
> pr_err("fwnode is neither OF or ACPI type\n");
> return -EINVAL;
> }
>
> /* check if we were a success in fetching pdev */
> if (!pdev) {
> pr_err("couldn't find platform device for node\n");
> return -ENODEV;
> }
>
> /* retrieve the dsaf_device from the driver data */
> dsaf_dev = dev_get_drvdata(&pdev->dev);
> if (!dsaf_dev) {
> dev_err(&pdev->dev, "dsaf_dev is NULL\n");
> return -ENODEV;
> }
>
> John
[...]
> > --- a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c
> > +++ b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c
> > @@ -3081,6 +3081,7 @@ int hns_dsaf_roce_reset(struct fwnode_handle *dsaf_fwnode, bool dereset)
> > dsaf_dev = dev_get_drvdata(&pdev->dev);
> > if (!dsaf_dev) {
> > dev_err(&pdev->dev, "dsaf_dev is NULL\n");
> > + put_device(&pdev->dev);
This looks okay.
> > return -ENODEV;
> > }
> >
> > @@ -3088,6 +3089,7 @@ int hns_dsaf_roce_reset(struct fwnode_handle *dsaf_fwnode, bool dereset)
> > if (AE_IS_VER1(dsaf_dev->dsaf_ver)) {
> > dev_err(dsaf_dev->dev, "%s v1 chip doesn't support RoCE!\n",
> > dsaf_dev->ae_dev.name);
> > + put_device(&pdev->dev);
This looks okay.
Salil.
On 15/02/2019 11:25, Salil Mehta wrote:
>> From: John Garry
>> Sent: Friday, February 15, 2019 10:52 AM
>>
>> On 14/02/2019 06:41, Huang Zijiang wrote:
>>> The of_find_device_by_node() takes a reference to the underlying device
>>> structure, we should release that reference.
>>
>> of_find_device_by_node() is not called for every path, so is this change proper:
>
>
> It looks okay to me and with the suggested device reference is being
> released from every possible error leg in the function. Could you be
> more specific which error path is not being addressed?
>
>
>
>> /* find the platform device corresponding to fwnode */
>> if (is_of_node(dsaf_fwnode)) {
>> pdev = of_find_device_by_node(to_of_node(dsaf_fwnode));
>
>
> This will get the reference to the device, which needs to be
> released later.
>
>
>> } else if (is_acpi_device_node(dsaf_fwnode)) {
>> pdev = hns_dsaf_find_platform_device(dsaf_fwnode);
>
>
> This will also get the reference to the device when bus_find_device()
> gets called and returns the 'device'. Therefore, this needs to be
> released as well using put_device()
OK, I see. That's non-obvious.
And so the commit message was simply incomplete.
>
So who finally drops this reference? This patch only seems to release on
error path. I checked the callers and they don't seem to.
John
>
>
>> } else {
>> pr_err("fwnode is neither OF or ACPI type\n");
>> return -EINVAL;
>> }
>>
>> /* check if we were a success in fetching pdev */
>> if (!pdev) {
>> pr_err("couldn't find platform device for node\n");
>> return -ENODEV;
>> }
>>
>> /* retrieve the dsaf_device from the driver data */
>> dsaf_dev = dev_get_drvdata(&pdev->dev);
>> if (!dsaf_dev) {
>> dev_err(&pdev->dev, "dsaf_dev is NULL\n");
>> return -ENODEV;
>> }
>>
>> John
>
>
> [...]
>
>>> --- a/drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c
>>> +++ b/drivers/net/ethernet/hisilicon/hns/hns_dsaf_main.c
>>> @@ -3081,6 +3081,7 @@ int hns_dsaf_roce_reset(struct fwnode_handle *dsaf_fwnode, bool dereset)
>>> dsaf_dev = dev_get_drvdata(&pdev->dev);
>>> if (!dsaf_dev) {
>>> dev_err(&pdev->dev, "dsaf_dev is NULL\n");
>>> + put_device(&pdev->dev);
>
>
> This looks okay.
>
>
>>> return -ENODEV;
>>> }
>>>
>>> @@ -3088,6 +3089,7 @@ int hns_dsaf_roce_reset(struct fwnode_handle *dsaf_fwnode, bool dereset)
>>> if (AE_IS_VER1(dsaf_dev->dsaf_ver)) {
>>> dev_err(dsaf_dev->dev, "%s v1 chip doesn't support RoCE!\n",
>>> dsaf_dev->ae_dev.name);
>>> + put_device(&pdev->dev);
>
>
> This looks okay.
>
>
> Salil.
>
> .
>
> From: John Garry
> Sent: Friday, February 15, 2019 12:00 PM
>
> On 15/02/2019 11:25, Salil Mehta wrote:
> >> From: John Garry
> >> Sent: Friday, February 15, 2019 10:52 AM
> >>
> >> On 14/02/2019 06:41, Huang Zijiang wrote:
> >>> The of_find_device_by_node() takes a reference to the underlying device
> >>> structure, we should release that reference.
> >>
> >> of_find_device_by_node() is not called for every path, so is this change proper:
> >
> >
> > It looks okay to me and with the suggested device reference is being
> > released from every possible error leg in the function. Could you be
> > more specific which error path is not being addressed?
> >
> >> /* find the platform device corresponding to fwnode */
> >> if (is_of_node(dsaf_fwnode)) {
> >> pdev = of_find_device_by_node(to_of_node(dsaf_fwnode));
> >
> >
> > This will get the reference to the device, which needs to be
> > released later.
> >
> >
> >> } else if (is_acpi_device_node(dsaf_fwnode)) {
> >> pdev = hns_dsaf_find_platform_device(dsaf_fwnode);
> >
> >
> > This will also get the reference to the device when bus_find_device()
> > gets called and returns the 'device'. Therefore, this needs to be
> > released as well using put_device()
>
> OK, I see. That's non-obvious.
>
> And so the commit message was simply incomplete.
>
> So who finally drops this reference? This patch only seems to release on
> error path. I checked the callers and they don't seem to.
Yes, in the positive leg the put_device() was missing. Thanks for identifying!
I have floated the patch to fix it https://www.lkml.org/lkml/2019/2/18/1161
Salil.