[PATCH] staging: greybus: loopback: use sysfs_emit in sysfs show functions

[PATCH] staging: greybus: loopback: use sysfs_emit in sysfs show functions

[Luis Soza Rodriguez]

As per the kernel's documentation, sysfs_emit() is the preferred way
to format strings for sysfs attributes. It handles buffer overruns
safely. Replace sprintf calls with sysfs_emit across all loopback
sysfs show macros.

Signed-off-by: Luis Soza Rodriguez <contact@sluisr.com>
---
 drivers/staging/greybus/loopback.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c
index aa9c73cb0..3a502d89d 100644
--- a/drivers/staging/greybus/loopback.c
+++ b/drivers/staging/greybus/loopback.c
@@ -125,7 +125,7 @@ static ssize_t field##_show(struct device *dev,			\
 			    char *buf)					\
 {									\
 	struct gb_loopback *gb = dev_get_drvdata(dev);			\
-	return sprintf(buf, "%u\n", gb->field);			\
+	return sysfs_emit(buf, "%u\n", gb->field);			\
 }									\
 static DEVICE_ATTR_RO(field)
 
@@ -137,8 +137,8 @@ static ssize_t name##_##field##_show(struct device *dev,	\
 	struct gb_loopback *gb = dev_get_drvdata(dev);			\
 	/* Report 0 for min and max if no transfer succeeded */		\
 	if (!gb->requests_completed)					\
-		return sprintf(buf, "0\n");				\
-	return sprintf(buf, "%" #type "\n", gb->name.field);		\
+		return sysfs_emit(buf, "0\n");				\
+	return sysfs_emit(buf, "%" #type "\n", gb->name.field);		\
 }									\
 static DEVICE_ATTR_RO(name##_##field)
 
@@ -158,7 +158,7 @@ static ssize_t name##_avg_show(struct device *dev,		\
 	rem = do_div(avg, count);					\
 	rem *= 1000000;							\
 	do_div(rem, count);						\
-	return sprintf(buf, "%llu.%06u\n", avg, (u32)rem);		\
+	return sysfs_emit(buf, "%llu.%06u\n", avg, (u32)rem);		\
 }									\
 static DEVICE_ATTR_RO(name##_avg)
 
@@ -173,7 +173,7 @@ static ssize_t field##_show(struct device *dev,				\
 			    char *buf)					\
 {									\
 	struct gb_loopback *gb = dev_get_drvdata(dev);			\
-	return sprintf(buf, "%" #type "\n", gb->field);			\
+	return sysfs_emit(buf, "%" #type "\n", gb->field);			\
 }									\
 static ssize_t field##_store(struct device *dev,			\
 			    struct device_attribute *attr,		\
@@ -199,7 +199,7 @@ static ssize_t field##_show(struct device *dev,		\
 			    char *buf)					\
 {									\
 	struct gb_loopback *gb = dev_get_drvdata(dev);			\
-	return sprintf(buf, "%u\n", gb->field);				\
+	return sysfs_emit(buf, "%u\n", gb->field);				\
 }									\
 static DEVICE_ATTR_RO(field)
 
@@ -209,7 +209,7 @@ static ssize_t field##_show(struct device *dev,				\
 			    char *buf)					\
 {									\
 	struct gb_loopback *gb = dev_get_drvdata(dev);			\
-	return sprintf(buf, "%" #type "\n", gb->field);			\
+	return sysfs_emit(buf, "%" #type "\n", gb->field);			\
 }									\
 static ssize_t field##_store(struct device *dev,			\
 			    struct device_attribute *attr,		\
-- 
2.53.0

Re: [PATCH] staging: greybus: loopback: use sysfs_emit in sysfs show functions

[Dan Carpenter]

On Mon, Mar 09, 2026 at 10:55:22AM -0600, Luis Soza Rodriguez wrote:
> As per the kernel's documentation, sysfs_emit() is the preferred way
> to format strings for sysfs attributes. It handles buffer overruns
> safely. Replace sprintf calls with sysfs_emit across all loopback
> sysfs show macros.
> 
> Signed-off-by: Luis Soza Rodriguez <contact@sluisr.com>
> ---
>  drivers/staging/greybus/loopback.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c
> index aa9c73cb0..3a502d89d 100644
> --- a/drivers/staging/greybus/loopback.c
> +++ b/drivers/staging/greybus/loopback.c
> @@ -125,7 +125,7 @@ static ssize_t field##_show(struct device *dev,			\
>  			    char *buf)					\
>  {									\
>  	struct gb_loopback *gb = dev_get_drvdata(dev);			\
> -	return sprintf(buf, "%u\n", gb->field);			\
> +	return sysfs_emit(buf, "%u\n", gb->field);			\
>  }									\
>  static DEVICE_ATTR_RO(field)
>  
> @@ -137,8 +137,8 @@ static ssize_t name##_##field##_show(struct device *dev,	\
>  	struct gb_loopback *gb = dev_get_drvdata(dev);			\
>  	/* Report 0 for min and max if no transfer succeeded */		\
>  	if (!gb->requests_completed)					\
> -		return sprintf(buf, "0\n");				\
> -	return sprintf(buf, "%" #type "\n", gb->name.field);		\
> +		return sysfs_emit(buf, "0\n");				\
> +	return sysfs_emit(buf, "%" #type "\n", gb->name.field);		\
>  }									\
>  static DEVICE_ATTR_RO(name##_##field)
>  
> @@ -158,7 +158,7 @@ static ssize_t name##_avg_show(struct device *dev,		\
>  	rem = do_div(avg, count);					\
>  	rem *= 1000000;							\
>  	do_div(rem, count);						\
> -	return sprintf(buf, "%llu.%06u\n", avg, (u32)rem);		\
> +	return sysfs_emit(buf, "%llu.%06u\n", avg, (u32)rem);		\
>  }									\
>  static DEVICE_ATTR_RO(name##_avg)
>  
> @@ -173,7 +173,7 @@ static ssize_t field##_show(struct device *dev,				\
>  			    char *buf)					\
>  {									\
>  	struct gb_loopback *gb = dev_get_drvdata(dev);			\
> -	return sprintf(buf, "%" #type "\n", gb->field);			\
> +	return sysfs_emit(buf, "%" #type "\n", gb->field);			\

Please, keep the \ characters aligned properly.

>  }									\
>  static ssize_t field##_store(struct device *dev,			\
>  			    struct device_attribute *attr,		\
> @@ -199,7 +199,7 @@ static ssize_t field##_show(struct device *dev,		\
>  			    char *buf)					\
>  {									\
>  	struct gb_loopback *gb = dev_get_drvdata(dev);			\
> -	return sprintf(buf, "%u\n", gb->field);				\
> +	return sysfs_emit(buf, "%u\n", gb->field);				\

Same.

>  }									\
>  static DEVICE_ATTR_RO(field)
>  
> @@ -209,7 +209,7 @@ static ssize_t field##_show(struct device *dev,				\
>  			    char *buf)					\
>  {									\
>  	struct gb_loopback *gb = dev_get_drvdata(dev);			\
> -	return sprintf(buf, "%" #type "\n", gb->field);			\
> +	return sysfs_emit(buf, "%" #type "\n", gb->field);			\

Same.

regards,
dan carpenter

>  }									\
>  static ssize_t field##_store(struct device *dev,			\
>  			    struct device_attribute *attr,		\