PM: hibernate: Use sysfs_emit() and sysfs_emit_at() in "show" functions

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

No functional change intended.

Signed-off-by: Xueqin Luo <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Rafael J. Wysocki <[email protected]>

Author: Xueqin Luo

kernel/power/hibernate.c

@@ -1123,11 +1123,11 @@ static const char * const hibernation_modes[] = {
 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
 			 char *buf)
 {
+	ssize_t count = 0;
 	int i;
-	char *start = buf;
 
 	if (!hibernation_available())
-		return sprintf(buf, "[disabled]\n");
+		return sysfs_emit(buf, "[disabled]\n");
 
 	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 		if (!hibernation_modes[i])
@@ -1147,12 +1147,16 @@ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
 			continue;
 		}
 		if (i == hibernation_mode)
-			buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
+			count += sysfs_emit_at(buf, count, "[%s] ", hibernation_modes[i]);
 		else
-			buf += sprintf(buf, "%s ", hibernation_modes[i]);
+			count += sysfs_emit_at(buf, count, "%s ", hibernation_modes[i]);
 	}
-	buf += sprintf(buf, "\n");
-	return buf-start;
+
+	/* Convert the last space to a newline if needed. */
+	if (count > 0)
+		buf[count - 1] = '\n';
+
+	return count;
 }
 
 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
@@ -1210,8 +1214,8 @@ power_attr(disk);
 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
 			   char *buf)
 {
-	return sprintf(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
-		       MINOR(swsusp_resume_device));
+	return sysfs_emit(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
+			  MINOR(swsusp_resume_device));
 }
 
 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
@@ -1270,7 +1274,7 @@ power_attr(resume);
 static ssize_t resume_offset_show(struct kobject *kobj,
 				  struct kobj_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
+	return sysfs_emit(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
 }
 
 static ssize_t resume_offset_store(struct kobject *kobj,
@@ -1293,7 +1297,7 @@ power_attr(resume_offset);
 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
 			       char *buf)
 {
-	return sprintf(buf, "%lu\n", image_size);
+	return sysfs_emit(buf, "%lu\n", image_size);
 }
 
 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
@@ -1314,7 +1318,7 @@ power_attr(image_size);
 static ssize_t reserved_size_show(struct kobject *kobj,
 				  struct kobj_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%lu\n", reserved_size);
+	return sysfs_emit(buf, "%lu\n", reserved_size);
 }
 
 static ssize_t reserved_size_store(struct kobject *kobj,