Re: [PATCH 9/9] drivers/acpi: correct error-handling code

[Zhang Rui <rui.zhang@intel.com>]

On Tue, 2009-07-28 at 23:56 +0800, Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
> 
> backlight_device_register may return an ERR_PTR value rather than a valid
> pointer.
> 
> A simplified version of the semantic match that finds this problem is as
> follows: (http://coccinelle.lip6.fr/)

> Signed-off-by: Julia Lawall <julia@diku.dk>
> 
> ---
>  drivers/acpi/video.c                |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
> index 8851315..29788db 100644
> --- a/drivers/acpi/video.c
> +++ b/drivers/acpi/video.c
> @@ -982,6 +982,8 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
>  		sprintf(name, "acpi_video%d", count++);
>  		device->backlight = backlight_device_register(name,
>  			NULL, device, &acpi_backlight_ops);
> +		if (IS_ERR(device->backlight))
> +			return;

we should kfree(name) here.

>  		device->backlight->props.max_brightness = device->brightness->count-3;
>  		kfree(name);

how about this one?

backlight_device_register may return an ERR_PTR value rather than a valid
pointer.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
---
 drivers/acpi/video.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Index: linux-2.6/drivers/acpi/video.c
===================================================================
--- linux-2.6.orig/drivers/acpi/video.c
+++ linux-2.6/drivers/acpi/video.c
@@ -982,8 +982,10 @@ static void acpi_video_device_find_cap(s
 		sprintf(name, "acpi_video%d", count++);
 		device->backlight = backlight_device_register(name,
 			NULL, device, &acpi_backlight_ops);
-		device->backlight->props.max_brightness = device->brightness->count-3;
 		kfree(name);
+		if (IS_ERR(device->backlight))
+			return;
+		device->backlight->props.max_brightness = device->brightness->count-3;
 
 		result = sysfs_create_link(&device->backlight->dev.kobj,
 					   &device->dev->dev.kobj, "device");



 

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