2022-05-12 23:07:06

by Eugeniu Rosca

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

From: Bhuvanesh Surachari <[email protected]>

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 <[email protected]>
Signed-off-by: Eugeniu Rosca <[email protected]>
---
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

2022-05-14 03:06:18

by Greg Kroah-Hartman

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

On Thu, May 12, 2022 at 01:15:27PM +0200, Eugeniu Rosca wrote:
> From: Bhuvanesh Surachari <[email protected]>
>
> 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 <[email protected]>
> Signed-off-by: Eugeniu Rosca <[email protected]>
> ---
> 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

2022-05-14 03:51:00

by Eugeniu Rosca

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

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 <[email protected]>

[..]

> > 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/[email protected]

Best regards,
Eugeniu