drivers core: Use sysfs_emit and sysfs_emit_at for show(device *...) functions

Convert the various sprintf fmaily calls in sysfs device show functions
to sysfs_emit and sysfs_emit_at for PAGE_SIZE buffer safety.

Done with:

$ spatch -sp-file sysfs_emit_dev.cocci --in-place --max-width=80 .

And cocci script:

$ cat sysfs_emit_dev.cocci
@@
identifier d_show;
identifier dev, attr, buf;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	<...
	return
-	sprintf(buf,
+	sysfs_emit(buf,
	...);
	...>
}

@@
identifier d_show;
identifier dev, attr, buf;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	<...
	return
-	snprintf(buf, PAGE_SIZE,
+	sysfs_emit(buf,
	...);
	...>
}

@@
identifier d_show;
identifier dev, attr, buf;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	<...
	return
-	scnprintf(buf, PAGE_SIZE,
+	sysfs_emit(buf,
	...);
	...>
}

@@
identifier d_show;
identifier dev, attr, buf;
expression chr;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	<...
	return
-	strcpy(buf, chr);
+	sysfs_emit(buf, chr);
	...>
}

@@
identifier d_show;
identifier dev, attr, buf;
identifier len;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	<...
	len =
-	sprintf(buf,
+	sysfs_emit(buf,
	...);
	...>
	return len;
}

@@
identifier d_show;
identifier dev, attr, buf;
identifier len;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	<...
	len =
-	snprintf(buf, PAGE_SIZE,
+	sysfs_emit(buf,
	...);
	...>
	return len;
}

@@
identifier d_show;
identifier dev, attr, buf;
identifier len;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	<...
	len =
-	scnprintf(buf, PAGE_SIZE,
+	sysfs_emit(buf,
	...);
	...>
	return len;
}

@@
identifier d_show;
identifier dev, attr, buf;
identifier len;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	<...
-	len += scnprintf(buf + len, PAGE_SIZE - len,
+	len += sysfs_emit_at(buf, len,
	...);
	...>
	return len;
}

@@
identifier d_show;
identifier dev, attr, buf;
expression chr;
@@

ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	...
-	strcpy(buf, chr);
-	return strlen(buf);
+	return sysfs_emit(buf, chr);
}

Signed-off-by: Joe Perches <joe@perches.com>
Link: https://lore.kernel.org/r/3d033c33056d88bbe34d4ddb62afd05ee166ab9a.1600285923.git.joe@perches.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/core.c

@@ -260,7 +260,7 @@ static ssize_t status_show(struct device *dev,
 	default:
 		status = "unknown"; break;
 	}
-	return sprintf(buf, "%s\n", status);
+	return sysfs_emit(buf, "%s\n", status);
 }
 static DEVICE_ATTR_RO(status);
 
@@ -277,7 +277,7 @@ static ssize_t auto_remove_on_show(struct device *dev,
 	else
 		str = "never";
 
-	return sprintf(buf, "%s\n", str);
+	return sysfs_emit(buf, "%s\n", str);
 }
 static DEVICE_ATTR_RO(auto_remove_on);
 
@@ -286,7 +286,7 @@ static ssize_t runtime_pm_show(struct device *dev,
 {
 	struct device_link *link = to_devlink(dev);
 
-	return sprintf(buf, "%d\n", !!(link->flags & DL_FLAG_PM_RUNTIME));
+	return sysfs_emit(buf, "%d\n", !!(link->flags & DL_FLAG_PM_RUNTIME));
 }
 static DEVICE_ATTR_RO(runtime_pm);
 
@@ -295,7 +295,8 @@ static ssize_t sync_state_only_show(struct device *dev,
 {
 	struct device_link *link = to_devlink(dev);
 
-	return sprintf(buf, "%d\n", !!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
+	return sysfs_emit(buf, "%d\n",
+			  !!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
 }
 static DEVICE_ATTR_RO(sync_state_only);
 
@@ -1060,7 +1061,7 @@ static ssize_t waiting_for_supplier_show(struct device *dev,
 	      && dev->links.need_for_probe;
 	mutex_unlock(&wfs_lock);
 	device_unlock(dev);
-	return sprintf(buf, "%u\n", val);
+	return sysfs_emit(buf, "%u\n", val);
 }
 static DEVICE_ATTR_RO(waiting_for_supplier);
 
@@ -1710,7 +1711,7 @@ ssize_t device_show_ulong(struct device *dev,
 			  char *buf)
 {
 	struct dev_ext_attribute *ea = to_ext_attr(attr);
-	return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
+	return sysfs_emit(buf, "%lx\n", *(unsigned long *)(ea->var));
 }
 EXPORT_SYMBOL_GPL(device_show_ulong);
 
@@ -1740,7 +1741,7 @@ ssize_t device_show_int(struct device *dev,
 {
 	struct dev_ext_attribute *ea = to_ext_attr(attr);
 
-	return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
+	return sysfs_emit(buf, "%d\n", *(int *)(ea->var));
 }
 EXPORT_SYMBOL_GPL(device_show_int);
 
@@ -1761,7 +1762,7 @@ ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
 {
 	struct dev_ext_attribute *ea = to_ext_attr(attr);
 
-	return snprintf(buf, PAGE_SIZE, "%d\n", *(bool *)(ea->var));
+	return sysfs_emit(buf, "%d\n", *(bool *)(ea->var));
 }
 EXPORT_SYMBOL_GPL(device_show_bool);
 
@@ -1993,7 +1994,7 @@ static ssize_t online_show(struct device *dev, struct device_attribute *attr,
 	device_lock(dev);
 	val = !dev->offline;
 	device_unlock(dev);
-	return sprintf(buf, "%u\n", val);
+	return sysfs_emit(buf, "%u\n", val);
 }
 
 static ssize_t online_store(struct device *dev, struct device_attribute *attr,