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| Started by | Amitoj Kaur Chawla <amitoj1606@gmail.com> |
|---|---|
| First post | 2016-01-22 19:10 +0100 |
| Last post | 2016-01-25 14:00 +0100 |
| Articles | 4 — 3 participants |
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[PATCH] bus: vexpress-config: Add missing of_node_put Amitoj Kaur Chawla <amitoj1606@gmail.com> - 2016-01-22 19:10 +0100
Re: [PATCH] bus: vexpress-config: Add missing of_node_put liviu.dudau@arm.com - 2016-01-25 13:20 +0100
Re: [PATCH] bus: vexpress-config: Add missing of_node_put Julia Lawall <julia.lawall@lip6.fr> - 2016-01-25 13:30 +0100
Re: [PATCH] bus: vexpress-config: Add missing of_node_put liviu.dudau@arm.com - 2016-01-25 14:00 +0100
| From | Amitoj Kaur Chawla <amitoj1606@gmail.com> |
|---|---|
| Date | 2016-01-22 19:10 +0100 |
| Subject | [PATCH] bus: vexpress-config: Add missing of_node_put |
| Message-ID | <qTOjM-7K8-19@gated-at.bofh.it> |
for_each_compatible_node performs an of_node_get on each iteration, so
to break out of the loop an of_node_put is required.
Found using Coccinelle. The semantic patch used for this is as follows:
// <smpl>
@@
expression e;
local idexpression n;
@@
for_each_compatible_node(n, ...) {
... when != of_node_put(n)
when != e = n
(
return n;
+ of_node_put(n);
? return ...;
)
...
}
// </smpl>
Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
---
drivers/bus/vexpress-config.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/bus/vexpress-config.c b/drivers/bus/vexpress-config.c
index 6575c0f..c3cb76b 100644
--- a/drivers/bus/vexpress-config.c
+++ b/drivers/bus/vexpress-config.c
@@ -192,8 +192,10 @@ static int __init vexpress_config_init(void)
/* Need the config devices early, before the "normal" devices... */
for_each_compatible_node(node, NULL, "arm,vexpress,config-bus") {
err = vexpress_config_populate(node);
- if (err)
+ if (err) {
+ of_node_put(node);
break;
+ }
}
return err;
--
1.9.1
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| From | liviu.dudau@arm.com |
|---|---|
| Date | 2016-01-25 13:20 +0100 |
| Message-ID | <qUOhH-3K1-1@gated-at.bofh.it> |
| In reply to | #1315182 |
On Fri, Jan 22, 2016 at 11:38:38PM +0530, Amitoj Kaur Chawla wrote:
> for_each_compatible_node performs an of_node_get on each iteration, so
> to break out of the loop an of_node_put is required.
>
> Found using Coccinelle. The semantic patch used for this is as follows:
>
> // <smpl>
> @@
> expression e;
> local idexpression n;
> @@
>
> for_each_compatible_node(n, ...) {
> ... when != of_node_put(n)
> when != e = n
> (
> return n;
> + of_node_put(n);
> ? return ...;
> )
> ...
> }
> // </smpl>
>
> Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Hi Amitoj,
> ---
> drivers/bus/vexpress-config.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/bus/vexpress-config.c b/drivers/bus/vexpress-config.c
> index 6575c0f..c3cb76b 100644
> --- a/drivers/bus/vexpress-config.c
> +++ b/drivers/bus/vexpress-config.c
> @@ -192,8 +192,10 @@ static int __init vexpress_config_init(void)
> /* Need the config devices early, before the "normal" devices... */
> for_each_compatible_node(node, NULL, "arm,vexpress,config-bus") {
> err = vexpress_config_populate(node);
> - if (err)
> + if (err) {
> + of_node_put(node);
> break;
> + }
This automatically generated patch only solves half of the problem (for the error
path).
> }
>
> return err;
> --
> 1.9.1
>
I feel that a better patch would be the following, where the node is released
regardless of the result of vexpress_config_populate().
--8<--------------------------------------------------------------------------
diff --git a/drivers/bus/vexpress-config.c b/drivers/bus/vexpress-config.c
index 6575c0f..c57453d 100644
--- a/drivers/bus/vexpress-config.c
+++ b/drivers/bus/vexpress-config.c
@@ -192,6 +192,7 @@ static int __init vexpress_config_init(void)
/* Need the config devices early, before the "normal" devices... */
for_each_compatible_node(node, NULL, "arm,vexpress,config-bus") {
err = vexpress_config_populate(node);
+ of_node_put(node);
if (err)
break;
}
-->8--------------------------------------------------------------------------
Best regards,
Liviu
--
====================
| I would like to |
| fix the world, |
| but they're not |
| giving me the |
\ source code! /
---------------
¯\_(ツ)_/¯
[toc] | [prev] | [next] | [standalone]
| From | Julia Lawall <julia.lawall@lip6.fr> |
|---|---|
| Date | 2016-01-25 13:30 +0100 |
| Message-ID | <qUOrn-3Og-9@gated-at.bofh.it> |
| In reply to | #1316604 |
[Multipart message — attachments visible in raw view] — view raw
On Mon, 25 Jan 2016, liviu.dudau@arm.com wrote:
> On Fri, Jan 22, 2016 at 11:38:38PM +0530, Amitoj Kaur Chawla wrote:
> > for_each_compatible_node performs an of_node_get on each iteration, so
> > to break out of the loop an of_node_put is required.
> >
> > Found using Coccinelle. The semantic patch used for this is as follows:
> >
> > // <smpl>
> > @@
> > expression e;
> > local idexpression n;
> > @@
> >
> > for_each_compatible_node(n, ...) {
> > ... when != of_node_put(n)
> > when != e = n
> > (
> > return n;
> > + of_node_put(n);
> > ? return ...;
> > )
> > ...
> > }
> > // </smpl>
> >
> > Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
>
> Hi Amitoj,
>
> > ---
> > drivers/bus/vexpress-config.c | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/bus/vexpress-config.c b/drivers/bus/vexpress-config.c
> > index 6575c0f..c3cb76b 100644
> > --- a/drivers/bus/vexpress-config.c
> > +++ b/drivers/bus/vexpress-config.c
> > @@ -192,8 +192,10 @@ static int __init vexpress_config_init(void)
> > /* Need the config devices early, before the "normal" devices... */
> > for_each_compatible_node(node, NULL, "arm,vexpress,config-bus") {
> > err = vexpress_config_populate(node);
> > - if (err)
> > + if (err) {
> > + of_node_put(node);
> > break;
> > + }
>
> This automatically generated patch only solves half of the problem (for the error
> path).
>
> > }
> >
> > return err;
> > --
> > 1.9.1
> >
>
> I feel that a better patch would be the following, where the node is released
> regardless of the result of vexpress_config_populate().
>
> --8<--------------------------------------------------------------------------
> diff --git a/drivers/bus/vexpress-config.c b/drivers/bus/vexpress-config.c
> index 6575c0f..c57453d 100644
> --- a/drivers/bus/vexpress-config.c
> +++ b/drivers/bus/vexpress-config.c
> @@ -192,6 +192,7 @@ static int __init vexpress_config_init(void)
> /* Need the config devices early, before the "normal" devices... */
> for_each_compatible_node(node, NULL, "arm,vexpress,config-bus") {
> err = vexpress_config_populate(node);
> + of_node_put(node);
This is not correct. for_each_compatible_node will do the free if you go
around the loop. This change would lead to a double free in the non error
case.
julia
> if (err)
> break;
> }
> -->8--------------------------------------------------------------------------
>
> Best regards,
> Liviu
>
> --
> ====================
> | I would like to |
> | fix the world, |
> | but they're not |
> | giving me the |
> \ source code! /
> ---------------
> ¯\_(ツ)_/¯
>
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| From | liviu.dudau@arm.com |
|---|---|
| Date | 2016-01-25 14:00 +0100 |
| Message-ID | <qUOUp-40h-1@gated-at.bofh.it> |
| In reply to | #1316617 |
On Mon, Jan 25, 2016 at 01:24:44PM +0100, Julia Lawall wrote:
>
>
> On Mon, 25 Jan 2016, liviu.dudau@arm.com wrote:
>
> > On Fri, Jan 22, 2016 at 11:38:38PM +0530, Amitoj Kaur Chawla wrote:
> > > for_each_compatible_node performs an of_node_get on each iteration, so
> > > to break out of the loop an of_node_put is required.
> > >
> > > Found using Coccinelle. The semantic patch used for this is as follows:
> > >
> > > // <smpl>
> > > @@
> > > expression e;
> > > local idexpression n;
> > > @@
> > >
> > > for_each_compatible_node(n, ...) {
> > > ... when != of_node_put(n)
> > > when != e = n
> > > (
> > > return n;
> > > + of_node_put(n);
> > > ? return ...;
> > > )
> > > ...
> > > }
> > > // </smpl>
> > >
> > > Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
> >
> > Hi Amitoj,
> >
> > > ---
> > > drivers/bus/vexpress-config.c | 4 +++-
> > > 1 file changed, 3 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/bus/vexpress-config.c b/drivers/bus/vexpress-config.c
> > > index 6575c0f..c3cb76b 100644
> > > --- a/drivers/bus/vexpress-config.c
> > > +++ b/drivers/bus/vexpress-config.c
> > > @@ -192,8 +192,10 @@ static int __init vexpress_config_init(void)
> > > /* Need the config devices early, before the "normal" devices... */
> > > for_each_compatible_node(node, NULL, "arm,vexpress,config-bus") {
> > > err = vexpress_config_populate(node);
> > > - if (err)
> > > + if (err) {
> > > + of_node_put(node);
> > > break;
> > > + }
> >
> > This automatically generated patch only solves half of the problem (for the error
> > path).
> >
> > > }
> > >
> > > return err;
> > > --
> > > 1.9.1
> > >
> >
> > I feel that a better patch would be the following, where the node is released
> > regardless of the result of vexpress_config_populate().
> >
> > --8<--------------------------------------------------------------------------
> > diff --git a/drivers/bus/vexpress-config.c b/drivers/bus/vexpress-config.c
> > index 6575c0f..c57453d 100644
> > --- a/drivers/bus/vexpress-config.c
> > +++ b/drivers/bus/vexpress-config.c
> > @@ -192,6 +192,7 @@ static int __init vexpress_config_init(void)
> > /* Need the config devices early, before the "normal" devices... */
> > for_each_compatible_node(node, NULL, "arm,vexpress,config-bus") {
> > err = vexpress_config_populate(node);
> > + of_node_put(node);
>
> This is not correct. for_each_compatible_node will do the free if you go
> around the loop. This change would lead to a double free in the non error
> case.
You are correct and I withdraw my patch.
For the original patch:
Acked-by: Liviu Dudau <Liviu.Dudau@arm.com>
Best regards,
Liviu
>
> julia
>
> > if (err)
> > break;
> > }
> > -->8--------------------------------------------------------------------------
--
====================
| I would like to |
| fix the world, |
| but they're not |
| giving me the |
\ source code! /
---------------
¯\_(ツ)_/¯
[toc] | [prev] | [standalone]
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