[v1] usb: hub: Simplify error and success path in port_over_current_notify

[PATCH] usb: hub: Simplify error and success path in port_over_current_notify

Posted by Eugeniu Rosca 3 years, 12 months ago

From: Bhuvanesh Surachari <Bhuvanesh_Surachari@mentor.com>

kasprintf() returns NULL or valid pointer. Since kfree() can handle
NULL pointer condition, simplify error and success paths in function
port_over_current_notify() by removing multiple error path labels.

Signed-off-by: Bhuvanesh Surachari <Bhuvanesh_Surachari@mentor.com>
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
---
 drivers/usb/core/hub.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 1460857026e0..9ab8abf14790 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -5511,7 +5511,7 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
 /* Handle notifying userspace about hub over-current events */
 static void port_over_current_notify(struct usb_port *port_dev)
 {
-	char *envp[3];
+	char *envp[3] = { NULL, NULL, NULL };
 	struct device *hub_dev;
 	char *port_dev_path;
 
@@ -5533,15 +5533,13 @@ static void port_over_current_notify(struct usb_port *port_dev)
 	envp[1] = kasprintf(GFP_KERNEL, "OVER_CURRENT_COUNT=%u",
 			port_dev->over_current_count);
 	if (!envp[1])
-		goto exit;
+		goto exit_path;
 
-	envp[2] = NULL;
 	kobject_uevent_env(&hub_dev->kobj, KOBJ_CHANGE, envp);
 
+exit_path:
 	kfree(envp[1]);
-exit:
 	kfree(envp[0]);
-exit_path:
 	kfree(port_dev_path);
 }
 
-- 
2.36.0

Re: [PATCH] usb: hub: Simplify error and success path in port_over_current_notify

Posted by Greg Kroah-Hartman 3 years, 12 months ago

On Thu, May 12, 2022 at 01:15:27PM +0200, Eugeniu Rosca wrote:
> From: Bhuvanesh Surachari <Bhuvanesh_Surachari@mentor.com>
> 
> kasprintf() returns NULL or valid pointer. Since kfree() can handle
> NULL pointer condition, simplify error and success paths in function
> port_over_current_notify() by removing multiple error path labels.
> 
> Signed-off-by: Bhuvanesh Surachari <Bhuvanesh_Surachari@mentor.com>
> Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
> ---
>  drivers/usb/core/hub.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index 1460857026e0..9ab8abf14790 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -5511,7 +5511,7 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1,
>  /* Handle notifying userspace about hub over-current events */
>  static void port_over_current_notify(struct usb_port *port_dev)
>  {
> -	char *envp[3];
> +	char *envp[3] = { NULL, NULL, NULL };
>  	struct device *hub_dev;
>  	char *port_dev_path;
>  
> @@ -5533,15 +5533,13 @@ static void port_over_current_notify(struct usb_port *port_dev)
>  	envp[1] = kasprintf(GFP_KERNEL, "OVER_CURRENT_COUNT=%u",
>  			port_dev->over_current_count);
>  	if (!envp[1])
> -		goto exit;
> +		goto exit_path;

No need to rename this, right?

>  
> -	envp[2] = NULL;
>  	kobject_uevent_env(&hub_dev->kobj, KOBJ_CHANGE, envp);
>  
> +exit_path:
>  	kfree(envp[1]);
> -exit:

Move this up one line?

thanks,

greg k-h

Re: [PATCH] usb: hub: Simplify error and success path in port_over_current_notify

Posted by Eugeniu Rosca 3 years, 12 months ago

Dear Greg,

On Do, Mai 12, 2022 at 01:38:36 +0200, Greg Kroah-Hartman wrote:
> On Thu, May 12, 2022 at 01:15:27PM +0200, Eugeniu Rosca wrote:
> > From: Bhuvanesh Surachari <Bhuvanesh_Surachari@mentor.com>

[..]

> >  	if (!envp[1])
> > -		goto exit;
> > +		goto exit_path;
> 
> No need to rename this, right?
> 
> >  
> > -	envp[2] = NULL;
> >  	kobject_uevent_env(&hub_dev->kobj, KOBJ_CHANGE, envp);
> >  
> > +exit_path:
> >  	kfree(envp[1]);
> > -exit:
> 
> Move this up one line?

Thank you for your comments. Much appreciated.

Please, find the updated version at:
https://lore.kernel.org/linux-usb/1652369834-4480-1-git-send-email-erosca@de.adit-jv.com

Best regards,
Eugeniu