* [PATCH] pci/hotplug/pnv-php: Remove probable double put
@ 2021-09-07 8:59 Xu Wang
2021-09-07 11:24 ` Bjorn Helgaas
2021-09-07 22:01 ` Tyrel Datwyler
0 siblings, 2 replies; 4+ messages in thread
From: Xu Wang @ 2021-09-07 8:59 UTC (permalink / raw)
To: mpe, benh, paulus, bhelgaas; +Cc: linux-pci, linuxppc-dev, linux-kernel
Device node iterators put the previous value of the index variable,
so an explicit put causes a double put.
Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
---
drivers/pci/hotplug/pnv_php.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c
index 04565162a449..ed4d1a2c3f22 100644
--- a/drivers/pci/hotplug/pnv_php.c
+++ b/drivers/pci/hotplug/pnv_php.c
@@ -158,7 +158,6 @@ static void pnv_php_detach_device_nodes(struct device_node *parent)
for_each_child_of_node(parent, dn) {
pnv_php_detach_device_nodes(dn);
- of_node_put(dn);
of_detach_node(dn);
}
}
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] pci/hotplug/pnv-php: Remove probable double put
2021-09-07 8:59 [PATCH] pci/hotplug/pnv-php: Remove probable double put Xu Wang
@ 2021-09-07 11:24 ` Bjorn Helgaas
2021-09-07 22:01 ` Tyrel Datwyler
1 sibling, 0 replies; 4+ messages in thread
From: Bjorn Helgaas @ 2021-09-07 11:24 UTC (permalink / raw)
To: Xu Wang; +Cc: linux-kernel, paulus, linux-pci, bhelgaas, linuxppc-dev
Make your subject line follow the previous convention.
Figure out if this is a "probable" or a real double put. If it's a
real double put, we should fix it. If it's only "probable," that
means we don't understand the problem yet.
On Tue, Sep 07, 2021 at 08:59:46AM +0000, Xu Wang wrote:
> Device node iterators put the previous value of the index variable,
> so an explicit put causes a double put.
>
> Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
> ---
> drivers/pci/hotplug/pnv_php.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c
> index 04565162a449..ed4d1a2c3f22 100644
> --- a/drivers/pci/hotplug/pnv_php.c
> +++ b/drivers/pci/hotplug/pnv_php.c
> @@ -158,7 +158,6 @@ static void pnv_php_detach_device_nodes(struct device_node *parent)
> for_each_child_of_node(parent, dn) {
> pnv_php_detach_device_nodes(dn);
>
> - of_node_put(dn);
> of_detach_node(dn);
> }
> }
> --
> 2.17.1
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] pci/hotplug/pnv-php: Remove probable double put
2021-09-07 8:59 [PATCH] pci/hotplug/pnv-php: Remove probable double put Xu Wang
2021-09-07 11:24 ` Bjorn Helgaas
@ 2021-09-07 22:01 ` Tyrel Datwyler
2021-09-07 23:17 ` Oliver O'Halloran
1 sibling, 1 reply; 4+ messages in thread
From: Tyrel Datwyler @ 2021-09-07 22:01 UTC (permalink / raw)
To: Xu Wang, mpe, benh, paulus, bhelgaas
Cc: linux-pci, linuxppc-dev, linux-kernel
On 9/7/21 1:59 AM, Xu Wang wrote:
> Device node iterators put the previous value of the index variable,
> so an explicit put causes a double put.
>
> Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
> ---
> drivers/pci/hotplug/pnv_php.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c
> index 04565162a449..ed4d1a2c3f22 100644
> --- a/drivers/pci/hotplug/pnv_php.c
> +++ b/drivers/pci/hotplug/pnv_php.c
> @@ -158,7 +158,6 @@ static void pnv_php_detach_device_nodes(struct device_node *parent)
> for_each_child_of_node(parent, dn) {
> pnv_php_detach_device_nodes(dn);
>
> - of_node_put(dn);
> of_detach_node(dn);
Are you sure this is a double put? This looks to me like its meant to drive tear
down of the device by putting a long term reference and not the short term get
that is part of the iterator.
-Tyrel
> }
> }
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] pci/hotplug/pnv-php: Remove probable double put
2021-09-07 22:01 ` Tyrel Datwyler
@ 2021-09-07 23:17 ` Oliver O'Halloran
0 siblings, 0 replies; 4+ messages in thread
From: Oliver O'Halloran @ 2021-09-07 23:17 UTC (permalink / raw)
To: Tyrel Datwyler
Cc: Linux Kernel Mailing List, Paul Mackerras, Xu Wang, linux-pci,
Bjorn Helgaas, linuxppc-dev
On Wed, Sep 8, 2021 at 8:02 AM Tyrel Datwyler <tyreld@linux.ibm.com> wrote:
>
> On 9/7/21 1:59 AM, Xu Wang wrote:
> > Device node iterators put the previous value of the index variable,
> > so an explicit put causes a double put.
> >
> > Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
> > ---
> > drivers/pci/hotplug/pnv_php.c | 1 -
> > 1 file changed, 1 deletion(-)
> >
> > diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c
> > index 04565162a449..ed4d1a2c3f22 100644
> > --- a/drivers/pci/hotplug/pnv_php.c
> > +++ b/drivers/pci/hotplug/pnv_php.c
> > @@ -158,7 +158,6 @@ static void pnv_php_detach_device_nodes(struct device_node *parent)
> > for_each_child_of_node(parent, dn) {
> > pnv_php_detach_device_nodes(dn);
> >
> > - of_node_put(dn);
> > of_detach_node(dn);
>
> Are you sure this is a double put? This looks to me like its meant to drive tear
> down of the device by putting a long term reference and not the short term get
> that is part of the iterator.
Yeah, the put is there is to drop the initial ref so the node can be
released. It might be worth adding a comment.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2021-09-07 8:59 [PATCH] pci/hotplug/pnv-php: Remove probable double put Xu Wang
2021-09-07 11:24 ` Bjorn Helgaas
2021-09-07 22:01 ` Tyrel Datwyler
2021-09-07 23:17 ` Oliver O'Halloran
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