Re: [PATCH] ASoC: Check list debugfs files for PAGE_SIZE overflow

[Liam Girdwood <lrg@slimlogic.co.uk>]

On Wed, 2010-10-13 at 10:46 +0100, Mark Brown wrote:
> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
> ---
>  sound/soc/soc-core.c |   51 ++++++++++++++++++++++++++++++++++---------------
>  1 files changed, 35 insertions(+), 16 deletions(-)
> 
> diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
> index dc1c567..4cbfe46 100644
> --- a/sound/soc/soc-core.c
> +++ b/sound/soc/soc-core.c
> @@ -275,15 +275,22 @@ static ssize_t codec_list_read_file(struct file *file, char __user *user_buf,
>  				    size_t count, loff_t *ppos)
>  {
>  	char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
> -	ssize_t ret = 0;
> +	ssize_t len, ret = 0;
>  	struct snd_soc_codec *codec;
>  
>  	if (!buf)
>  		return -ENOMEM;
>  
> -	list_for_each_entry(codec, &codec_list, list)
> -		ret += snprintf(buf + ret, PAGE_SIZE - ret, "%s\n",
> -				codec->name);
> +	list_for_each_entry(codec, &codec_list, list) {
> +		len = snprintf(buf + ret, PAGE_SIZE - ret, "%s\n",
> +			       codec->name);
> +		if (len >= 0)
> +			ret += len;
> +		if (ret > PAGE_SIZE) {
> +			ret = PAGE_SIZE;
> +			break;
> +		}
> +	}
>  
>  	if (ret >= 0)
>  		ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
> @@ -302,17 +309,23 @@ static ssize_t dai_list_read_file(struct file *file, char __user *user_buf,
>  				  size_t count, loff_t *ppos)
>  {
>  	char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
> -	ssize_t ret = 0;
> +	ssize_t len, ret = 0;
>  	struct snd_soc_dai *dai;
>  
>  	if (!buf)
>  		return -ENOMEM;
>  
> -	list_for_each_entry(dai, &dai_list, list)
> -		ret += snprintf(buf + ret, PAGE_SIZE - ret, "%s\n", dai->name);
> +	list_for_each_entry(dai, &dai_list, list) {
> +		len = snprintf(buf + ret, PAGE_SIZE - ret, "%s\n", dai->name);
> +		if (len >= 0)
> +			ret += len;
> +		if (ret > PAGE_SIZE) {
> +			ret = PAGE_SIZE;
> +			break;
> +		}
> +	}
>  
> -	if (ret >= 0)
> -		ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
> +	ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
>  
>  	kfree(buf);
>  
> @@ -329,18 +342,24 @@ static ssize_t platform_list_read_file(struct file *file,
>  				       size_t count, loff_t *ppos)
>  {
>  	char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
> -	ssize_t ret = 0;
> +	ssize_t len, ret = 0;
>  	struct snd_soc_platform *platform;
>  
>  	if (!buf)
>  		return -ENOMEM;
>  
> -	list_for_each_entry(platform, &platform_list, list)
> -		ret += snprintf(buf + ret, PAGE_SIZE - ret, "%s\n",
> -				platform->name);
> +	list_for_each_entry(platform, &platform_list, list) {
> +		len = snprintf(buf + ret, PAGE_SIZE - ret, "%s\n",
> +			       platform->name);
> +		if (len >= 0)
> +			ret += len;
> +		if (ret > PAGE_SIZE) {
> +			ret = PAGE_SIZE;
> +			break;
> +		}
> +	}
>  
> -	if (ret >= 0)
> -		ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
> +	ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
>  
>  	kfree(buf);
>  
> @@ -3015,11 +3034,11 @@ int snd_soc_register_dais(struct device *dev,
>  		}
>  
>  		dai->dev = dev;
> +		dai->driver = &dai_drv[i];
>  		if (dai->driver->id)
>  			dai->id = dai->driver->id;
>  		else
>  			dai->id = i;
> -		dai->driver = &dai_drv[i];
>  		if (!dai->driver->ops)
>  			dai->driver->ops = &null_dai_ops;
>  

Looks like you have the DAI id fix in here too. I assume this is mean to
be a separate patch ?

Liam
-- 
Freelance Developer, SlimLogic Ltd
ASoC and Voltage Regulator Maintainer.
http://www.slimlogic.co.uk