[PATCH] watchdog: Use sysfs_emit() and sysfs_emit_at() in "show" functions

[Guenter Roeck]

On 5/10/21 11:18 PM, Juerg Haefliger wrote:
> Convert sprintf() in sysfs "show" functions to sysfs_emit() and
> sysfs_emit_at() in order to check for buffer overruns in sysfs outputs.
> 
> Signed-off-by: Juerg Haefliger <juergh at canonical.com>

Reviewed-by: Guenter Roeck <linux at roeck-us.net>

> ---
>   drivers/watchdog/aspeed_wdt.c          |  4 ++--
>   drivers/watchdog/watchdog_dev.c        | 19 ++++++++++---------
>   drivers/watchdog/watchdog_pretimeout.c |  4 ++--
>   drivers/watchdog/ziirave_wdt.c         | 12 +++++++-----
>   4 files changed, 21 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c
> index 7e00960651fa..933998e5a9de 100644
> --- a/drivers/watchdog/aspeed_wdt.c
> +++ b/drivers/watchdog/aspeed_wdt.c
> @@ -175,8 +175,8 @@ static ssize_t access_cs0_show(struct device *dev,
>   	struct aspeed_wdt *wdt = dev_get_drvdata(dev);
>   	u32 status = readl(wdt->base + WDT_TIMEOUT_STATUS);
>   
> -	return sprintf(buf, "%u\n",
> -		      !(status & WDT_TIMEOUT_STATUS_BOOT_SECONDARY));
> +	return sysfs_emit(buf, "%u\n",
> +			  !(status & WDT_TIMEOUT_STATUS_BOOT_SECONDARY));
>   }
>   
>   static ssize_t access_cs0_store(struct device *dev,
> diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
> index 2946f3a63110..fe68a97973a5 100644
> --- a/drivers/watchdog/watchdog_dev.c
> +++ b/drivers/watchdog/watchdog_dev.c
> @@ -451,7 +451,8 @@ static ssize_t nowayout_show(struct device *dev, struct device_attribute *attr,
>   {
>   	struct watchdog_device *wdd = dev_get_drvdata(dev);
>   
> -	return sprintf(buf, "%d\n", !!test_bit(WDOG_NO_WAY_OUT, &wdd->status));
> +	return sysfs_emit(buf, "%d\n", !!test_bit(WDOG_NO_WAY_OUT,
> +						  &wdd->status));
>   }
>   
>   static ssize_t nowayout_store(struct device *dev, struct device_attribute *attr,
> @@ -485,7 +486,7 @@ static ssize_t status_show(struct device *dev, struct device_attribute *attr,
>   	status = watchdog_get_status(wdd);
>   	mutex_unlock(&wd_data->lock);
>   
> -	return sprintf(buf, "0x%x\n", status);
> +	return sysfs_emit(buf, "0x%x\n", status);
>   }
>   static DEVICE_ATTR_RO(status);
>   
> @@ -494,7 +495,7 @@ static ssize_t bootstatus_show(struct device *dev,
>   {
>   	struct watchdog_device *wdd = dev_get_drvdata(dev);
>   
> -	return sprintf(buf, "%u\n", wdd->bootstatus);
> +	return sysfs_emit(buf, "%u\n", wdd->bootstatus);
>   }
>   static DEVICE_ATTR_RO(bootstatus);
>   
> @@ -510,7 +511,7 @@ static ssize_t timeleft_show(struct device *dev, struct device_attribute *attr,
>   	status = watchdog_get_timeleft(wdd, &val);
>   	mutex_unlock(&wd_data->lock);
>   	if (!status)
> -		status = sprintf(buf, "%u\n", val);
> +		status = sysfs_emit(buf, "%u\n", val);
>   
>   	return status;
>   }
> @@ -521,7 +522,7 @@ static ssize_t timeout_show(struct device *dev, struct device_attribute *attr,
>   {
>   	struct watchdog_device *wdd = dev_get_drvdata(dev);
>   
> -	return sprintf(buf, "%u\n", wdd->timeout);
> +	return sysfs_emit(buf, "%u\n", wdd->timeout);
>   }
>   static DEVICE_ATTR_RO(timeout);
>   
> @@ -530,7 +531,7 @@ static ssize_t pretimeout_show(struct device *dev,
>   {
>   	struct watchdog_device *wdd = dev_get_drvdata(dev);
>   
> -	return sprintf(buf, "%u\n", wdd->pretimeout);
> +	return sysfs_emit(buf, "%u\n", wdd->pretimeout);
>   }
>   static DEVICE_ATTR_RO(pretimeout);
>   
> @@ -539,7 +540,7 @@ static ssize_t identity_show(struct device *dev, struct device_attribute *attr,
>   {
>   	struct watchdog_device *wdd = dev_get_drvdata(dev);
>   
> -	return sprintf(buf, "%s\n", wdd->info->identity);
> +	return sysfs_emit(buf, "%s\n", wdd->info->identity);
>   }
>   static DEVICE_ATTR_RO(identity);
>   
> @@ -549,9 +550,9 @@ static ssize_t state_show(struct device *dev, struct device_attribute *attr,
>   	struct watchdog_device *wdd = dev_get_drvdata(dev);
>   
>   	if (watchdog_active(wdd))
> -		return sprintf(buf, "active\n");
> +		return sysfs_emit(buf, "active\n");
>   
> -	return sprintf(buf, "inactive\n");
> +	return sysfs_emit(buf, "inactive\n");
>   }
>   static DEVICE_ATTR_RO(state);
>   
> diff --git a/drivers/watchdog/watchdog_pretimeout.c b/drivers/watchdog/watchdog_pretimeout.c
> index 01ca84be240f..7f257c3485cd 100644
> --- a/drivers/watchdog/watchdog_pretimeout.c
> +++ b/drivers/watchdog/watchdog_pretimeout.c
> @@ -55,7 +55,7 @@ int watchdog_pretimeout_available_governors_get(char *buf)
>   	mutex_lock(&governor_lock);
>   
>   	list_for_each_entry(priv, &governor_list, entry)
> -		count += sprintf(buf + count, "%s\n", priv->gov->name);
> +		count += sysfs_emit_at(buf, count, "%s\n", priv->gov->name);
>   
>   	mutex_unlock(&governor_lock);
>   
> @@ -68,7 +68,7 @@ int watchdog_pretimeout_governor_get(struct watchdog_device *wdd, char *buf)
>   
>   	spin_lock_irq(&pretimeout_lock);
>   	if (wdd->gov)
> -		count = sprintf(buf, "%s\n", wdd->gov->name);
> +		count = sysfs_emit(buf, "%s\n", wdd->gov->name);
>   	spin_unlock_irq(&pretimeout_lock);
>   
>   	return count;
> diff --git a/drivers/watchdog/ziirave_wdt.c b/drivers/watchdog/ziirave_wdt.c
> index 4297280807ca..6c9414d09684 100644
> --- a/drivers/watchdog/ziirave_wdt.c
> +++ b/drivers/watchdog/ziirave_wdt.c
> @@ -445,8 +445,9 @@ static ssize_t ziirave_wdt_sysfs_show_firm(struct device *dev,
>   	if (ret)
>   		return ret;
>   
> -	ret = sprintf(buf, ZIIRAVE_FW_VERSION_FMT, w_priv->firmware_rev.major,
> -		      w_priv->firmware_rev.minor);
> +	ret = sysfs_emit(buf, ZIIRAVE_FW_VERSION_FMT,
> +			 w_priv->firmware_rev.major,
> +			 w_priv->firmware_rev.minor);
>   
>   	mutex_unlock(&w_priv->sysfs_mutex);
>   
> @@ -468,8 +469,9 @@ static ssize_t ziirave_wdt_sysfs_show_boot(struct device *dev,
>   	if (ret)
>   		return ret;
>   
> -	ret = sprintf(buf, ZIIRAVE_BL_VERSION_FMT, w_priv->bootloader_rev.major,
> -		      w_priv->bootloader_rev.minor);
> +	ret = sysfs_emit(buf, ZIIRAVE_BL_VERSION_FMT,
> +			 w_priv->bootloader_rev.major,
> +			 w_priv->bootloader_rev.minor);
>   
>   	mutex_unlock(&w_priv->sysfs_mutex);
>   
> @@ -491,7 +493,7 @@ static ssize_t ziirave_wdt_sysfs_show_reason(struct device *dev,
>   	if (ret)
>   		return ret;
>   
> -	ret = sprintf(buf, "%s", ziirave_reasons[w_priv->reset_reason]);
> +	ret = sysfs_emit(buf, "%s", ziirave_reasons[w_priv->reset_reason]);
>   
>   	mutex_unlock(&w_priv->sysfs_mutex);
>   
>