[-next] PCI: dra7xx: Add missing of_node_put() in dra7xx_pcie_init_irq_domain()
diff mbox

Message ID 1476716077-30379-1-git-send-email-weiyj.lk@gmail.com
State New
Headers show

Commit Message

Wei Yongjun Oct. 17, 2016, 2:54 p.m. UTC
From: Wei Yongjun <weiyongjun1@huawei.com>

This node pointer is returned by of_get_next_child() with refcount
incremented in this function. of_node_put() on it before exitting
this function on error.

This is detected by Coccinelle semantic patch.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
---
 drivers/pci/host/pci-dra7xx.c | 1 +
 1 file changed, 1 insertion(+)

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Comments

Bjorn Helgaas Nov. 11, 2016, 9:38 p.m. UTC | #1
On Mon, Oct 17, 2016 at 02:54:37PM +0000, Wei Yongjun wrote:
> From: Wei Yongjun <weiyongjun1@huawei.com>
> 
> This node pointer is returned by of_get_next_child() with refcount
> incremented in this function. of_node_put() on it before exitting
> this function on error.
> 
> This is detected by Coccinelle semantic patch.
> 
> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>

Kishon, this looks correct to me, so I applied it to pci/host-dra7xx for
v4.10.  Let me know if you have any issue with it.

> ---
>  drivers/pci/host/pci-dra7xx.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/pci/host/pci-dra7xx.c b/drivers/pci/host/pci-dra7xx.c
> index 9595fad..79297e9 100644
> --- a/drivers/pci/host/pci-dra7xx.c
> +++ b/drivers/pci/host/pci-dra7xx.c
> @@ -177,6 +177,7 @@ static int dra7xx_pcie_init_irq_domain(struct pcie_port *pp)
>  					       &intx_domain_ops, pp);
>  	if (!pp->irq_domain) {
>  		dev_err(dev, "Failed to get a INTx IRQ domain\n");
> +		of_node_put(pcie_intc_node);
>  		return -ENODEV;
>  	}
> 
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Kishon Vijay Abraham I Nov. 12, 2016, 7:09 a.m. UTC | #2
Hi,

On Saturday 12 November 2016 03:08 AM, Bjorn Helgaas wrote:
> On Mon, Oct 17, 2016 at 02:54:37PM +0000, Wei Yongjun wrote:
>> From: Wei Yongjun <weiyongjun1@huawei.com>
>>
>> This node pointer is returned by of_get_next_child() with refcount
>> incremented in this function. of_node_put() on it before exitting
>> this function on error.
>>
>> This is detected by Coccinelle semantic patch.
>>
>> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
> 
> Kishon, this looks correct to me, so I applied it to pci/host-dra7xx for
> v4.10.  Let me know if you have any issue with it.
> 
>> ---
>>  drivers/pci/host/pci-dra7xx.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/pci/host/pci-dra7xx.c b/drivers/pci/host/pci-dra7xx.c
>> index 9595fad..79297e9 100644
>> --- a/drivers/pci/host/pci-dra7xx.c
>> +++ b/drivers/pci/host/pci-dra7xx.c
>> @@ -177,6 +177,7 @@ static int dra7xx_pcie_init_irq_domain(struct pcie_port *pp)
>>  					       &intx_domain_ops, pp);
>>  	if (!pp->irq_domain) {
>>  		dev_err(dev, "Failed to get a INTx IRQ domain\n");
>> +		of_node_put(pcie_intc_node);

I think of_node_put should be used for both the error case and non-error case.

Thanks
Kishon
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Bjorn Helgaas Nov. 14, 2016, 9:19 p.m. UTC | #3
[+cc Shawn, Heiko, Michal, Soren, Bharat, Rob H, Frank, devicetree@vger]

On Sat, Nov 12, 2016 at 12:39:01PM +0530, Kishon Vijay Abraham I wrote:
> Hi,
> 
> On Saturday 12 November 2016 03:08 AM, Bjorn Helgaas wrote:
> > On Mon, Oct 17, 2016 at 02:54:37PM +0000, Wei Yongjun wrote:
> >> From: Wei Yongjun <weiyongjun1@huawei.com>
> >>
> >> This node pointer is returned by of_get_next_child() with refcount
> >> incremented in this function. of_node_put() on it before exitting
> >> this function on error.
> >>
> >> This is detected by Coccinelle semantic patch.
> >>
> >> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
> > 
> > Kishon, this looks correct to me, so I applied it to pci/host-dra7xx for
> > v4.10.  Let me know if you have any issue with it.
> > 
> >> ---
> >>  drivers/pci/host/pci-dra7xx.c | 1 +
> >>  1 file changed, 1 insertion(+)
> >>
> >> diff --git a/drivers/pci/host/pci-dra7xx.c b/drivers/pci/host/pci-dra7xx.c
> >> index 9595fad..79297e9 100644
> >> --- a/drivers/pci/host/pci-dra7xx.c
> >> +++ b/drivers/pci/host/pci-dra7xx.c
> >> @@ -177,6 +177,7 @@ static int dra7xx_pcie_init_irq_domain(struct pcie_port *pp)
> >>  					       &intx_domain_ops, pp);
> >>  	if (!pp->irq_domain) {
> >>  		dev_err(dev, "Failed to get a INTx IRQ domain\n");
> >> +		of_node_put(pcie_intc_node);
> 
> I think of_node_put should be used for both the error case and non-error case.

Hmm, OK.  I don't know what the rules are.  Certainly if we made these
drivers modular, I don't think we'd want to leak these references
every time we unload/reload the module.  Should we do the put
immediately here, or in the module remove path, or ...?

Adding other driver and DT folks for comment.

I dropped these patches for now (dra7xx, rockchip, xilinx-nwl,
xilinx).
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Heiko Stübner Nov. 14, 2016, 9:37 p.m. UTC | #4
Am Montag, 14. November 2016, 15:19:28 CET schrieb Bjorn Helgaas:
> [+cc Shawn, Heiko, Michal, Soren, Bharat, Rob H, Frank, devicetree@vger]
> 
> On Sat, Nov 12, 2016 at 12:39:01PM +0530, Kishon Vijay Abraham I wrote:
> > Hi,
> > 
> > On Saturday 12 November 2016 03:08 AM, Bjorn Helgaas wrote:
> > > On Mon, Oct 17, 2016 at 02:54:37PM +0000, Wei Yongjun wrote:
> > >> From: Wei Yongjun <weiyongjun1@huawei.com>
> > >> 
> > >> This node pointer is returned by of_get_next_child() with refcount
> > >> incremented in this function. of_node_put() on it before exitting
> > >> this function on error.
> > >> 
> > >> This is detected by Coccinelle semantic patch.
> > >> 
> > >> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
> > > 
> > > Kishon, this looks correct to me, so I applied it to pci/host-dra7xx for
> > > v4.10.  Let me know if you have any issue with it.
> > > 
> > >> ---
> > >> 
> > >>  drivers/pci/host/pci-dra7xx.c | 1 +
> > >>  1 file changed, 1 insertion(+)
> > >> 
> > >> diff --git a/drivers/pci/host/pci-dra7xx.c
> > >> b/drivers/pci/host/pci-dra7xx.c
> > >> index 9595fad..79297e9 100644
> > >> --- a/drivers/pci/host/pci-dra7xx.c
> > >> +++ b/drivers/pci/host/pci-dra7xx.c
> > >> @@ -177,6 +177,7 @@ static int dra7xx_pcie_init_irq_domain(struct
> > >> pcie_port *pp)> >> 
> > >>  					       &intx_domain_ops, pp);
> > >>  	
> > >>  	if (!pp->irq_domain) {
> > >>  	
> > >>  		dev_err(dev, "Failed to get a INTx IRQ domain\n");
> > >> 
> > >> +		of_node_put(pcie_intc_node);
> > 
> > I think of_node_put should be used for both the error case and non-error
> > case.
> Hmm, OK.  I don't know what the rules are.  Certainly if we made these
> drivers modular, I don't think we'd want to leak these references
> every time we unload/reload the module.  Should we do the put
> immediately here, or in the module remove path, or ...?
> 
> Adding other driver and DT folks for comment.

I think the function above (dra7xx_pcie_init_irq_domain) can do the 
of_node_put at its end in all cases as suggested by Kishon.

of_get_next_child() will increment the refcount
	irq_domain_add_linear()
		__irq_domain_add() also increments the refcount


irq_domain_remove() will decrement the refcount

So it should be safe to decrement the refcount in 
dra7xx_pcie_init_irq_domain() in all cases as the irq-domain internals will 
always keep it above 1 as long as the node is used.


Heiko


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Patch
diff mbox

diff --git a/drivers/pci/host/pci-dra7xx.c b/drivers/pci/host/pci-dra7xx.c
index 9595fad..79297e9 100644
--- a/drivers/pci/host/pci-dra7xx.c
+++ b/drivers/pci/host/pci-dra7xx.c
@@ -177,6 +177,7 @@  static int dra7xx_pcie_init_irq_domain(struct pcie_port *pp)
 					       &intx_domain_ops, pp);
 	if (!pp->irq_domain) {
 		dev_err(dev, "Failed to get a INTx IRQ domain\n");
+		of_node_put(pcie_intc_node);
 		return -ENODEV;
 	}