[PATCH] isa: put_device after failing to device_register

[PATCH] isa: put_device after failing to device_register

[Zhi Song]

device_register() is used to register a device with the system.

We cannot directly free dev after calling this function,
even if it returns an error.

We should use put_device() to give up the reference
initialized in this function instead.

Signed-off-by: Zhi Song <zhi.song@bytedance.com>
---
 drivers/base/isa.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/base/isa.c b/drivers/base/isa.c
index 55e3ee2da98f..cf88f3d77b7d 100644
--- a/drivers/base/isa.c
+++ b/drivers/base/isa.c
@@ -173,8 +173,10 @@ static int __init isa_bus_init(void)
 	error = bus_register(&isa_bus_type);
 	if (!error) {
 		error = device_register(&isa_bus);
-		if (error)
+		if (error) {
+			put_device(&isa_bus);
 			bus_unregister(&isa_bus_type);
+		}
 	}
 	return error;
 }
-- 
2.30.2

Re: [PATCH] isa: put_device after failing to device_register

[Greg KH]

On Tue, Jun 14, 2022 at 10:57:57PM +0800, Zhi Song wrote:
> device_register() is used to register a device with the system.
> 
> We cannot directly free dev after calling this function,
> even if it returns an error.
> 
> We should use put_device() to give up the reference
> initialized in this function instead.

Same comments on this one as my last review.

greg k-h

[PATCH] isa: put_device after failing to device_register

[Zhi Song]

device_register() is used to register a device with the system.
We need to call put_device() to give up the reference initialized
in device_register() when it returns an error and this will clean
up correctly.

Signed-off-by: Zhi Song <zhi.song@bytedance.com>
---
 drivers/base/isa.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/base/isa.c b/drivers/base/isa.c
index 55e3ee2da98f..cf88f3d77b7d 100644
--- a/drivers/base/isa.c
+++ b/drivers/base/isa.c
@@ -173,8 +173,10 @@ static int __init isa_bus_init(void)
 	error = bus_register(&isa_bus_type);
 	if (!error) {
 		error = device_register(&isa_bus);
-		if (error)
+		if (error) {
+			put_device(&isa_bus);
 			bus_unregister(&isa_bus_type);
+		}
 	}
 	return error;
 }
-- 
2.30.2

Re: [PATCH] isa: put_device after failing to device_register

[Greg KH]

On Wed, Jun 15, 2022 at 12:01:26AM +0800, Zhi Song wrote:
> device_register() is used to register a device with the system.
> We need to call put_device() to give up the reference initialized
> in device_register() when it returns an error and this will clean
> up correctly.
> 
> Signed-off-by: Zhi Song <zhi.song@bytedance.com>
> ---
>  drivers/base/isa.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/base/isa.c b/drivers/base/isa.c
> index 55e3ee2da98f..cf88f3d77b7d 100644
> --- a/drivers/base/isa.c
> +++ b/drivers/base/isa.c
> @@ -173,8 +173,10 @@ static int __init isa_bus_init(void)
>  	error = bus_register(&isa_bus_type);
>  	if (!error) {
>  		error = device_register(&isa_bus);
> -		if (error)
> +		if (error) {
> +			put_device(&isa_bus);
>  			bus_unregister(&isa_bus_type);
> +		}
>  	}
>  	return error;
>  }
> -- 
> 2.30.2
> 

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
as indicated below:

- This looks like a new version of a previously submitted patch, but you
  did not list below the --- line any changes from the previous version.
  Please read the section entitled "The canonical patch format" in the
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If you wish to discuss this problem further, or you have questions about
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thanks,

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