diff mbox series

[2/7] scsi: Convert snprintf() to scnprintf()

Message ID YzHyC191CIXZSfc5@fedora
State New
Headers show
Series None | expand

Commit Message

Jules Irenge Sept. 26, 2022, 6:40 p.m. UTC 
Coccinnelle reports a warning
Warning: Use scnprintf or sprintf
Adding to that, there has been a slow migration from snprintf to scnprintf.
This LWN article explains the rationale for this change
https: //lwn.net/Articles/69419/
Ie. snprintf() returns what *would* be the resulting length,
while scnprintf() returns the actual length.

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
---
 drivers/scsi/scsi_sysfs.c | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

Comments

Jules Irenge Sept. 28, 2022, 1:37 p.m. UTC | #1 
On Mon, Sep 26, 2022 at 12:14:05PM -0700, Bart Van Assche wrote:
> On 9/26/22 11:40, Jules Irenge wrote:
> > Coccinnelle reports a warning
> > Warning: Use scnprintf or sprintf
> > Adding to that, there has been a slow migration from snprintf to scnprintf.
> > This LWN article explains the rationale for this change
> > https: //lwn.net/Articles/69419/
> > Ie. snprintf() returns what *would* be the resulting length,
> > while scnprintf() returns the actual length.
> 
> Isn't using snprintf() or scnprintf() inside sysfs show callbacks considered
> deprecated?
> 
You are right.

sysfs_emit() is preferred here.
If I have the blessing of the maintainer, I will go ahead and send a
second version with those changes.

Thanks,
Jules
Martin K. Petersen Oct. 1, 2022, 9:44 a.m. UTC | #2 
Jules,

> sysfs_emit() is preferred here.  If I have the blessing of the
> maintainer, I will go ahead and send a second version with those
> changes.

I'll consider a sysfs_emit() patch. However, I truly wish the code
checkers would limit their warnings to places were overflows are
actually possible.
diff mbox series

Patch

diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 5d61f58399dc..b1bfb8af0760 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -228,7 +228,7 @@  show_shost_state(struct device *dev, struct device_attribute *attr, char *buf)
 	if (!name)
 		return -EINVAL;
 
-	return snprintf(buf, 20, "%s\n", name);
+	return scnprintf(buf, 20, "%s\n", name);
 }
 
 /* DEVICE_ATTR(state) clashes with dev_attr_state for sdev */
@@ -274,7 +274,7 @@  show_shost_active_mode(struct device *dev,
 	struct Scsi_Host *shost = class_to_shost(dev);
 
 	if (shost->active_mode == MODE_UNKNOWN)
-		return snprintf(buf, 20, "unknown\n");
+		return scnprintf(buf, 20, "unknown\n");
 	else
 		return show_shost_mode(shost->active_mode, buf);
 }
@@ -324,7 +324,7 @@  show_shost_eh_deadline(struct device *dev,
 	struct Scsi_Host *shost = class_to_shost(dev);
 
 	if (shost->eh_deadline == -1)
-		return snprintf(buf, strlen("off") + 2, "off\n");
+		return scnprintf(buf, strlen("off") + 2, "off\n");
 	return sprintf(buf, "%u\n", shost->eh_deadline / HZ);
 }
 
@@ -382,7 +382,7 @@  static ssize_t
 show_host_busy(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct Scsi_Host *shost = class_to_shost(dev);
-	return snprintf(buf, 20, "%d\n", scsi_host_busy(shost));
+	return scnprintf(buf, 20, "%d\n", scsi_host_busy(shost));
 }
 static DEVICE_ATTR(host_busy, S_IRUGO, show_host_busy, NULL);
 
@@ -399,7 +399,7 @@  show_nr_hw_queues(struct device *dev, struct device_attribute *attr, char *buf)
 	struct Scsi_Host *shost = class_to_shost(dev);
 	struct blk_mq_tag_set *tag_set = &shost->tag_set;
 
-	return snprintf(buf, 20, "%d\n", tag_set->nr_hw_queues);
+	return scnprintf(buf, 20, "%d\n", tag_set->nr_hw_queues);
 }
 static DEVICE_ATTR(nr_hw_queues, S_IRUGO, show_nr_hw_queues, NULL);
 
@@ -692,7 +692,7 @@  sdev_show_device_busy(struct device *dev, struct device_attribute *attr,
 		char *buf)
 {
 	struct scsi_device *sdev = to_scsi_device(dev);
-	return snprintf(buf, 20, "%d\n", scsi_device_busy(sdev));
+	return scnprintf(buf, 20, "%d\n", scsi_device_busy(sdev));
 }
 static DEVICE_ATTR(device_busy, S_IRUGO, sdev_show_device_busy, NULL);
 
@@ -701,7 +701,7 @@  sdev_show_device_blocked(struct device *dev, struct device_attribute *attr,
 		char *buf)
 {
 	struct scsi_device *sdev = to_scsi_device(dev);
-	return snprintf(buf, 20, "%d\n", atomic_read(&sdev->device_blocked));
+	return scnprintf(buf, 20, "%d\n", atomic_read(&sdev->device_blocked));
 }
 static DEVICE_ATTR(device_blocked, S_IRUGO, sdev_show_device_blocked, NULL);
 
@@ -713,7 +713,7 @@  sdev_show_timeout (struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct scsi_device *sdev;
 	sdev = to_scsi_device(dev);
-	return snprintf(buf, 20, "%d\n", sdev->request_queue->rq_timeout / HZ);
+	return scnprintf(buf, 20, "%d\n", sdev->request_queue->rq_timeout / HZ);
 }
 
 static ssize_t
@@ -734,7 +734,7 @@  sdev_show_eh_timeout(struct device *dev, struct device_attribute *attr, char *bu
 {
 	struct scsi_device *sdev;
 	sdev = to_scsi_device(dev);
-	return snprintf(buf, 20, "%u\n", sdev->eh_timeout / HZ);
+	return scnprintf(buf, 20, "%u\n", sdev->eh_timeout / HZ);
 }
 
 static ssize_t
@@ -862,7 +862,7 @@  show_state_field(struct device *dev, struct device_attribute *attr, char *buf)
 	if (!name)
 		return -EINVAL;
 
-	return snprintf(buf, 20, "%s\n", name);
+	return scnprintf(buf, 20, "%s\n", name);
 }
 
 static DEVICE_ATTR(state, S_IRUGO | S_IWUSR, show_state_field, store_state_field);
@@ -877,7 +877,7 @@  show_queue_type_field(struct device *dev, struct device_attribute *attr,
 	if (sdev->simple_tags)
 		name = "simple";
 
-	return snprintf(buf, 20, "%s\n", name);
+	return scnprintf(buf, 20, "%s\n", name);
 }
 
 static ssize_t
@@ -957,7 +957,7 @@  static ssize_t
 show_iostat_counterbits(struct device *dev, struct device_attribute *attr,
 			char *buf)
 {
-	return snprintf(buf, 20, "%d\n", (int)sizeof(atomic_t) * 8);
+	return scnprintf(buf, 20, "%d\n", (int)sizeof(atomic_t) * 8);
 }
 
 static DEVICE_ATTR(iocounterbits, S_IRUGO, show_iostat_counterbits, NULL);
@@ -982,7 +982,7 @@  sdev_show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct scsi_device *sdev;
 	sdev = to_scsi_device(dev);
-	return snprintf (buf, 20, SCSI_DEVICE_MODALIAS_FMT "\n", sdev->type);
+	return scnprintf (buf, 20, SCSI_DEVICE_MODALIAS_FMT "\n", sdev->type);
 }
 static DEVICE_ATTR(modalias, S_IRUGO, sdev_show_modalias, NULL);
 
@@ -1115,7 +1115,7 @@  sdev_show_dh_state(struct device *dev, struct device_attribute *attr,
 	struct scsi_device *sdev = to_scsi_device(dev);
 
 	if (!sdev->handler)
-		return snprintf(buf, 20, "detached\n");
+		return scnprintf(buf, 20, "detached\n");
 
 	return snprintf(buf, 20, "%s\n", sdev->handler->name);
 }
@@ -1205,7 +1205,7 @@  sdev_show_queue_ramp_up_period(struct device *dev,
 {
 	struct scsi_device *sdev;
 	sdev = to_scsi_device(dev);
-	return snprintf(buf, 20, "%u\n",
+	return scnprintf(buf, 20, "%u\n",
 			jiffies_to_msecs(sdev->queue_ramp_up_period));
 }