linux-kernel - Re: [PATCH v2] acpi_system_write_wakeup_device(): fix error check for unsigned variable.

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Message-ID: <27097726.Soe6qubrSj@vostro.rjw.lan>
Date:	Thu, 22 Nov 2012 23:40:26 +0100
From:	"Rafael J. Wysocki" <rjw@...k.pl>
To:	Cyril Roelandt <tipecaml@...il.com>
Cc:	linux-kernel@...r.kernel.org, linux-acpi@...r.kernel.org,
	lenb@...nel.org, kernel-janitors@...r.kernel.org
Subject: Re: [PATCH v2] acpi_system_write_wakeup_device(): fix error check for unsigned variable.

On Thursday, November 22, 2012 01:34:55 AM Cyril Roelandt wrote:
> The LEN variable is unsigned, therefore checking whether it is less than 0 is
> useless. Also drop the LEN variable, since the COUNT parameter can be used
> instead.

Applied (under a different subject).

Thanks,
Rafael


> Signed-off-by: Cyril Roelandt <tipecaml@...il.com>
> ---
>  drivers/acpi/proc.c |   11 ++++-------
>  1 file changed, 4 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/acpi/proc.c b/drivers/acpi/proc.c
> index 27adb09..ef98796 100644
> --- a/drivers/acpi/proc.c
> +++ b/drivers/acpi/proc.c
> @@ -362,16 +362,13 @@ acpi_system_write_wakeup_device(struct file *file,
>  	struct list_head *node, *next;
>  	char strbuf[5];
>  	char str[5] = "";
> -	unsigned int len = count;
>  
> -	if (len > 4)
> -		len = 4;
> -	if (len < 0)
> -		return -EFAULT;
> +	if (count > 4)
> +		count = 4;
>  
> -	if (copy_from_user(strbuf, buffer, len))
> +	if (copy_from_user(strbuf, buffer, count))
>  		return -EFAULT;
> -	strbuf[len] = '\0';
> +	strbuf[count] = '\0';
>  	sscanf(strbuf, "%s", str);
>  
>  	mutex_lock(&acpi_device_lock);
> 
-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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