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* [PATCH] bus: vexpress-config: Add missing of_node_put
@ 2016-01-22 18:08 ` Amitoj Kaur Chawla
  0 siblings, 0 replies; 8+ messages in thread
From: Amitoj Kaur Chawla @ 2016-01-22 18:08 UTC (permalink / raw)
  To: liviu.dudau, sudeep.holla, lorenzo.pieralisi, linux-kernel,
	linux-arm-kernel
  Cc: julia.lawall

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

^ permalink raw reply related	[flat|nested] 8+ messages in thread
* [PATCH] bus: vexpress-config: Add missing of_node_put
@ 2016-01-22 18:08 ` Amitoj Kaur Chawla
  0 siblings, 0 replies; 8+ messages in thread
From: Amitoj Kaur Chawla @ 2016-01-22 18:08 UTC (permalink / raw)
  To: linux-arm-kernel

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

^ permalink raw reply related	[flat|nested] 8+ messages in thread
* Re: [PATCH] bus: vexpress-config: Add missing of_node_put
  2016-01-22 18:08 ` Amitoj Kaur Chawla
@ 2016-01-25 12:17   ` liviu.dudau at arm.com
  -1 siblings, 0 replies; 8+ messages in thread
From: liviu.dudau @ 2016-01-25 12:17 UTC (permalink / raw)
  To: Amitoj Kaur Chawla
  Cc: sudeep.holla, lorenzo.pieralisi, linux-kernel, linux-arm-kernel,
	julia.lawall

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)_/¯

^ permalink raw reply related	[flat|nested] 8+ messages in thread
* [PATCH] bus: vexpress-config: Add missing of_node_put
@ 2016-01-25 12:17   ` liviu.dudau at arm.com
  0 siblings, 0 replies; 8+ messages in thread
From: liviu.dudau at arm.com @ 2016-01-25 12:17 UTC (permalink / raw)
  To: linux-arm-kernel

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!  /
  ---------------
    ?\_(?)_/?

^ permalink raw reply related	[flat|nested] 8+ messages in thread
* Re: [PATCH] bus: vexpress-config: Add missing of_node_put
  2016-01-25 12:17   ` liviu.dudau at arm.com
@ 2016-01-25 12:24     ` Julia Lawall
  -1 siblings, 0 replies; 8+ messages in thread
From: Julia Lawall @ 2016-01-25 12:24 UTC (permalink / raw)
  To: liviu.dudau
  Cc: Amitoj Kaur Chawla, sudeep.holla, lorenzo.pieralisi,
	linux-kernel, linux-arm-kernel

[-- Attachment #1: Type: TEXT/PLAIN, Size: 2661 bytes --]



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)_/¯
>

^ permalink raw reply	[flat|nested] 8+ messages in thread
* [PATCH] bus: vexpress-config: Add missing of_node_put
@ 2016-01-25 12:24     ` Julia Lawall
  0 siblings, 0 replies; 8+ messages in thread
From: Julia Lawall @ 2016-01-25 12:24 UTC (permalink / raw)
  To: linux-arm-kernel



On Mon, 25 Jan 2016, liviu.dudau at 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!  /
>   ---------------
>     ?\_(?)_/?
>

^ permalink raw reply	[flat|nested] 8+ messages in thread
* Re: [PATCH] bus: vexpress-config: Add missing of_node_put
  2016-01-25 12:24     ` Julia Lawall
@ 2016-01-25 12:51       ` liviu.dudau at arm.com
  -1 siblings, 0 replies; 8+ messages in thread
From: liviu.dudau @ 2016-01-25 12:51 UTC (permalink / raw)
  To: Julia Lawall
  Cc: Amitoj Kaur Chawla, sudeep.holla, lorenzo.pieralisi,
	linux-kernel, linux-arm-kernel

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)_/¯

^ permalink raw reply	[flat|nested] 8+ messages in thread
* [PATCH] bus: vexpress-config: Add missing of_node_put
@ 2016-01-25 12:51       ` liviu.dudau at arm.com
  0 siblings, 0 replies; 8+ messages in thread
From: liviu.dudau at arm.com @ 2016-01-25 12:51 UTC (permalink / raw)
  To: linux-arm-kernel

On Mon, Jan 25, 2016 at 01:24:44PM +0100, Julia Lawall wrote:
> 
> 
> On Mon, 25 Jan 2016, liviu.dudau at 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!  /
  ---------------
    ?\_(?)_/?

^ permalink raw reply	[flat|nested] 8+ messages in thread
end of thread, other threads:[~2016-01-25 12:51 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-01-22 18:08 [PATCH] bus: vexpress-config: Add missing of_node_put Amitoj Kaur Chawla
2016-01-22 18:08 ` Amitoj Kaur Chawla
2016-01-25 12:17 ` liviu.dudau
2016-01-25 12:17   ` liviu.dudau at arm.com
2016-01-25 12:24   ` Julia Lawall
2016-01-25 12:24     ` Julia Lawall
2016-01-25 12:51     ` liviu.dudau
2016-01-25 12:51       ` liviu.dudau at arm.com

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