[PATCH] s390/cio: Convert sprintf/snprintf to sysfs_emit

[PATCH] s390/cio: Convert sprintf/snprintf to sysfs_emit

[Li Zhijian]

Per filesystems/sysfs.rst, show() should only use sysfs_emit()
or sysfs_emit_at() when formatting the value to be returned to user space.

coccinelle complains that there are still a couple of functions that use
snprintf(). Convert them to sysfs_emit().

sprintf() will be converted as weel if they have.

Generally, this patch is generated by
make coccicheck M=<path/to/file> MODE=patch \
COCCI=scripts/coccinelle/api/device_attr_show.cocci

No functional change intended

CC: Vineeth Vijayan <vneethv@linux.ibm.com>
CC: Peter Oberparleiter <oberpar@linux.ibm.com>
CC: Heiko Carstens <hca@linux.ibm.com>
CC: Vasily Gorbik <gor@linux.ibm.com>
CC: Alexander Gordeev <agordeev@linux.ibm.com>
CC: Christian Borntraeger <borntraeger@linux.ibm.com>
CC: Sven Schnelle <svens@linux.ibm.com>
CC: linux-s390@vger.kernel.org
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
---
This is a part of the work "Fix coccicheck device_attr_show warnings"[1]
Split them per subsystem so that the maintainer can review it easily
[1] https://lore.kernel.org/lkml/20240116041129.3937800-1-lizhijian@fujitsu.com/
---
 drivers/s390/cio/css.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 094431a62ad5..4fec251ec35d 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -309,7 +309,7 @@ static ssize_t type_show(struct device *dev, struct device_attribute *attr,
 {
 	struct subchannel *sch = to_subchannel(dev);
 
-	return sprintf(buf, "%01x\n", sch->st);
+	return sysfs_emit(buf, "%01x\n", sch->st);
 }
 
 static DEVICE_ATTR_RO(type);
@@ -319,7 +319,7 @@ static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 {
 	struct subchannel *sch = to_subchannel(dev);
 
-	return sprintf(buf, "css:t%01X\n", sch->st);
+	return sysfs_emit(buf, "css:t%01X\n", sch->st);
 }
 
 static DEVICE_ATTR_RO(modalias);
@@ -345,7 +345,7 @@ static ssize_t driver_override_show(struct device *dev,
 	ssize_t len;
 
 	device_lock(dev);
-	len = snprintf(buf, PAGE_SIZE, "%s\n", sch->driver_override);
+	len = sysfs_emit(buf, "%s\n", sch->driver_override);
 	device_unlock(dev);
 	return len;
 }
@@ -396,7 +396,7 @@ static ssize_t pimpampom_show(struct device *dev,
 	struct subchannel *sch = to_subchannel(dev);
 	struct pmcw *pmcw = &sch->schib.pmcw;
 
-	return sprintf(buf, "%02x %02x %02x\n",
+	return sysfs_emit(buf, "%02x %02x %02x\n",
 		       pmcw->pim, pmcw->pam, pmcw->pom);
 }
 static DEVICE_ATTR_RO(pimpampom);
@@ -881,7 +881,7 @@ static ssize_t real_cssid_show(struct device *dev, struct device_attribute *a,
 	if (!css->id_valid)
 		return -EINVAL;
 
-	return sprintf(buf, "%x\n", css->cssid);
+	return sysfs_emit(buf, "%x\n", css->cssid);
 }
 static DEVICE_ATTR_RO(real_cssid);
 
@@ -904,7 +904,7 @@ static ssize_t cm_enable_show(struct device *dev, struct device_attribute *a,
 	int ret;
 
 	mutex_lock(&css->mutex);
-	ret = sprintf(buf, "%x\n", css->cm_enabled);
+	ret = sysfs_emit(buf, "%x\n", css->cm_enabled);
 	mutex_unlock(&css->mutex);
 	return ret;
 }
-- 
2.29.2

Re: [PATCH] s390/cio: Convert sprintf/snprintf to sysfs_emit

[Heiko Carstens]

On Thu, Mar 14, 2024 at 05:52:09PM +0800, Li Zhijian wrote:
> Per filesystems/sysfs.rst, show() should only use sysfs_emit()
> or sysfs_emit_at() when formatting the value to be returned to user space.
> 
> coccinelle complains that there are still a couple of functions that use
> snprintf(). Convert them to sysfs_emit().
> 
> sprintf() will be converted as weel if they have.
> 
> Generally, this patch is generated by
> make coccicheck M=<path/to/file> MODE=patch \
> COCCI=scripts/coccinelle/api/device_attr_show.cocci
> 
> No functional change intended
> 
> CC: Vineeth Vijayan <vneethv@linux.ibm.com>
> CC: Peter Oberparleiter <oberpar@linux.ibm.com>
> CC: Heiko Carstens <hca@linux.ibm.com>
> CC: Vasily Gorbik <gor@linux.ibm.com>
> CC: Alexander Gordeev <agordeev@linux.ibm.com>
> CC: Christian Borntraeger <borntraeger@linux.ibm.com>
> CC: Sven Schnelle <svens@linux.ibm.com>
> CC: linux-s390@vger.kernel.org
> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
> ---
> This is a part of the work "Fix coccicheck device_attr_show warnings"[1]
> Split them per subsystem so that the maintainer can review it easily
> [1] https://lore.kernel.org/lkml/20240116041129.3937800-1-lizhijian@fujitsu.com/
> ---
>  drivers/s390/cio/css.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)

Applied, but...

> @@ -396,7 +396,7 @@ static ssize_t pimpampom_show(struct device *dev,
>  	struct subchannel *sch = to_subchannel(dev);
>  	struct pmcw *pmcw = &sch->schib.pmcw;
>  
> -	return sprintf(buf, "%02x %02x %02x\n",
> +	return sysfs_emit(buf, "%02x %02x %02x\n",
>  		       pmcw->pim, pmcw->pam, pmcw->pom);

...please make sure to fix such whitespace / indentation errors if you
plan to provide more patches. I fixed it this time.

Thanks!