--- zzzz-none-000/linux-3.10.107/drivers/tty/hvc/hvc_iucv.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/tty/hvc/hvc_iucv.c	2021-02-04 17:41:59.000000000 +0000
@@ -1,10 +1,10 @@
 /*
- * hvc_iucv.c - z/VM IUCV hypervisor console (HVC) device driver
+ * z/VM IUCV hypervisor console (HVC) device driver
  *
  * This HVC device driver provides terminal access using
  * z/VM IUCV communication paths.
  *
- * Copyright IBM Corp. 2008, 2009
+ * Copyright IBM Corp. 2008, 2013
  *
  * Author(s):	Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
  */
@@ -77,6 +77,7 @@
 	struct list_head	tty_outqueue;	/* outgoing IUCV messages */
 	struct list_head	tty_inqueue;	/* incoming IUCV messages */
 	struct device		*dev;		/* device structure */
+	u8			info_path[16];	/* IUCV path info (dev attr) */
 };
 
 struct iucv_tty_buffer {
@@ -87,8 +88,8 @@
 };
 
 /* IUCV callback handler */
-static	int hvc_iucv_path_pending(struct iucv_path *, u8[8], u8[16]);
-static void hvc_iucv_path_severed(struct iucv_path *, u8[16]);
+static	int hvc_iucv_path_pending(struct iucv_path *, u8 *, u8 *);
+static void hvc_iucv_path_severed(struct iucv_path *, u8 *);
 static void hvc_iucv_msg_pending(struct iucv_path *, struct iucv_message *);
 static void hvc_iucv_msg_complete(struct iucv_path *, struct iucv_message *);
 
@@ -101,6 +102,7 @@
 #define IUCV_HVC_CON_IDX	(0)
 /* List of z/VM user ID filter entries (struct iucv_vmid_filter) */
 #define MAX_VMID_FILTER		(500)
+#define FILTER_WILDCARD_CHAR	'*'
 static size_t hvc_iucv_filter_size;
 static void *hvc_iucv_filter;
 static const char *hvc_iucv_filter_string;
@@ -126,7 +128,7 @@
  * This function returns the struct hvc_iucv_private instance that corresponds
  * to the HVC virtual terminal number specified as parameter @num.
  */
-struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num)
+static struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num)
 {
 	if ((num < HVC_IUCV_MAGIC) || (num - HVC_IUCV_MAGIC > hvc_iucv_devices))
 		return NULL;
@@ -656,21 +658,64 @@
 }
 
 /**
+ * hvc_iucv_dtr_rts() - HVC notifier for handling DTR/RTS
+ * @hp:		Pointer the HVC device (struct hvc_struct)
+ * @raise:	Non-zero to raise or zero to lower DTR/RTS lines
+ *
+ * This routine notifies the HVC back-end to raise or lower DTR/RTS
+ * lines.  Raising DTR/RTS is ignored.  Lowering DTR/RTS indicates to
+ * drop the IUCV connection (similar to hang up the modem).
+ */
+static void hvc_iucv_dtr_rts(struct hvc_struct *hp, int raise)
+{
+	struct hvc_iucv_private *priv;
+	struct iucv_path        *path;
+
+	/* Raising the DTR/RTS is ignored as IUCV connections can be
+	 * established at any times.
+	 */
+	if (raise)
+		return;
+
+	priv = hvc_iucv_get_private(hp->vtermno);
+	if (!priv)
+		return;
+
+	/* Lowering the DTR/RTS lines disconnects an established IUCV
+	 * connection.
+	 */
+	flush_sndbuf_sync(priv);
+
+	spin_lock_bh(&priv->lock);
+	path = priv->path;		/* save reference to IUCV path */
+	priv->path = NULL;
+	priv->iucv_state = IUCV_DISCONN;
+	spin_unlock_bh(&priv->lock);
+
+	/* Sever IUCV path outside of priv->lock due to lock ordering of:
+	 * priv->lock <--> iucv_table_lock */
+	if (path) {
+		iucv_path_sever(path, NULL);
+		iucv_path_free(path);
+	}
+}
+
+/**
  * hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time.
  * @hp:		Pointer to the HVC device (struct hvc_struct)
  * @id:		Additional data (originally passed to hvc_alloc):
  *		the index of an struct hvc_iucv_private instance.
  *
  * This routine notifies the HVC back-end that the last tty device fd has been
- * closed.  The function calls hvc_iucv_cleanup() to clean up the struct
- * hvc_iucv_private instance.
+ * closed.  The function cleans up tty resources.  The clean-up of the IUCV
+ * connection is done in hvc_iucv_dtr_rts() and depends on the HUPCL termios
+ * control setting.
  *
  * Locking:	struct hvc_iucv_private->lock
  */
 static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id)
 {
 	struct hvc_iucv_private *priv;
-	struct iucv_path	*path;
 
 	priv = hvc_iucv_get_private(id);
 	if (!priv)
@@ -679,37 +724,42 @@
 	flush_sndbuf_sync(priv);
 
 	spin_lock_bh(&priv->lock);
-	path = priv->path;		/* save reference to IUCV path */
-	priv->path = NULL;
-	hvc_iucv_cleanup(priv);
+	destroy_tty_buffer_list(&priv->tty_outqueue);
+	destroy_tty_buffer_list(&priv->tty_inqueue);
+	priv->tty_state = TTY_CLOSED;
+	priv->sndbuf_len = 0;
 	spin_unlock_bh(&priv->lock);
-
-	/* sever IUCV path outside of priv->lock due to lock ordering of:
-	 * priv->lock <--> iucv_table_lock */
-	if (path) {
-		iucv_path_sever(path, NULL);
-		iucv_path_free(path);
-	}
 }
 
 /**
  * hvc_iucv_filter_connreq() - Filter connection request based on z/VM user ID
  * @ipvmid:	Originating z/VM user ID (right padded with blanks)
  *
- * Returns 0 if the z/VM user ID @ipvmid is allowed to connection, otherwise
- * non-zero.
+ * Returns 0 if the z/VM user ID that is specified with @ipvmid is permitted to
+ * connect, otherwise non-zero.
  */
 static int hvc_iucv_filter_connreq(u8 ipvmid[8])
 {
-	size_t i;
+	const char *wildcard, *filter_entry;
+	size_t i, len;
 
 	/* Note: default policy is ACCEPT if no filter is set */
 	if (!hvc_iucv_filter_size)
 		return 0;
 
-	for (i = 0; i < hvc_iucv_filter_size; i++)
-		if (0 == memcmp(ipvmid, hvc_iucv_filter + (8 * i), 8))
+	for (i = 0; i < hvc_iucv_filter_size; i++) {
+		filter_entry = hvc_iucv_filter + (8 * i);
+
+		/* If a filter entry contains the filter wildcard character,
+		 * reduce the length to match the leading portion of the user
+		 * ID only (wildcard match).  Characters following the wildcard
+		 * are ignored.
+		 */
+		wildcard = strnchr(filter_entry, 8, FILTER_WILDCARD_CHAR);
+		len = (wildcard) ? wildcard - filter_entry : 8;
+		if (0 == memcmp(ipvmid, filter_entry, len))
 			return 0;
+	}
 	return 1;
 }
 
@@ -732,21 +782,40 @@
  *
  * Locking:	struct hvc_iucv_private->lock
  */
-static	int hvc_iucv_path_pending(struct iucv_path *path,
-				  u8 ipvmid[8], u8 ipuser[16])
+static	int hvc_iucv_path_pending(struct iucv_path *path, u8 *ipvmid,
+				  u8 *ipuser)
 {
-	struct hvc_iucv_private *priv;
+	struct hvc_iucv_private *priv, *tmp;
+	u8 wildcard[9] = "lnxhvc  ";
+	int i, rc, find_unused;
 	u8 nuser_data[16];
 	u8 vm_user_id[9];
-	int i, rc;
 
+	ASCEBC(wildcard, sizeof(wildcard));
+	find_unused = !memcmp(wildcard, ipuser, 8);
+
+	/* First, check if the pending path request is managed by this
+	 * IUCV handler:
+	 * - find a disconnected device if ipuser contains the wildcard
+	 * - find the device that matches the terminal ID in ipuser
+	 */
 	priv = NULL;
-	for (i = 0; i < hvc_iucv_devices; i++)
-		if (hvc_iucv_table[i] &&
-		    (0 == memcmp(hvc_iucv_table[i]->srv_name, ipuser, 8))) {
-			priv = hvc_iucv_table[i];
+	for (i = 0; i < hvc_iucv_devices; i++) {
+		tmp = hvc_iucv_table[i];
+		if (!tmp)
+			continue;
+
+		if (find_unused) {
+			spin_lock(&tmp->lock);
+			if (tmp->iucv_state == IUCV_DISCONN)
+				priv = tmp;
+			spin_unlock(&tmp->lock);
+
+		} else if (!memcmp(tmp->srv_name, ipuser, 8))
+				priv = tmp;
+		if (priv)
 			break;
-		}
+	}
 	if (!priv)
 		return -ENODEV;
 
@@ -789,6 +858,10 @@
 	priv->path = path;
 	priv->iucv_state = IUCV_CONNECTED;
 
+	/* store path information */
+	memcpy(priv->info_path, ipvmid, 8);
+	memcpy(priv->info_path + 8, ipuser + 8, 8);
+
 	/* flush buffered output data... */
 	schedule_delayed_work(&priv->sndbuf_work, 5);
 
@@ -808,7 +881,7 @@
  *
  * Locking:	struct hvc_iucv_private->lock
  */
-static void hvc_iucv_path_severed(struct iucv_path *path, u8 ipuser[16])
+static void hvc_iucv_path_severed(struct iucv_path *path, u8 *ipuser)
 {
 	struct hvc_iucv_private *priv = path->private;
 
@@ -923,6 +996,49 @@
 	return 0;
 }
 
+static ssize_t hvc_iucv_dev_termid_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct hvc_iucv_private *priv = dev_get_drvdata(dev);
+	size_t len;
+
+	len = sizeof(priv->srv_name);
+	memcpy(buf, priv->srv_name, len);
+	EBCASC(buf, len);
+	buf[len++] = '\n';
+	return len;
+}
+
+static ssize_t hvc_iucv_dev_state_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct hvc_iucv_private *priv = dev_get_drvdata(dev);
+	return sprintf(buf, "%u:%u\n", priv->iucv_state, priv->tty_state);
+}
+
+static ssize_t hvc_iucv_dev_peer_show(struct device *dev,
+				      struct device_attribute *attr,
+				      char *buf)
+{
+	struct hvc_iucv_private *priv = dev_get_drvdata(dev);
+	char vmid[9], ipuser[9];
+
+	memset(vmid, 0, sizeof(vmid));
+	memset(ipuser, 0, sizeof(ipuser));
+
+	spin_lock_bh(&priv->lock);
+	if (priv->iucv_state == IUCV_CONNECTED) {
+		memcpy(vmid, priv->info_path, 8);
+		memcpy(ipuser, priv->info_path + 8, 8);
+	}
+	spin_unlock_bh(&priv->lock);
+	EBCASC(ipuser, 8);
+
+	return sprintf(buf, "%s:%s\n", vmid, ipuser);
+}
+
 
 /* HVC operations */
 static const struct hv_ops hvc_iucv_ops = {
@@ -931,6 +1047,7 @@
 	.notifier_add = hvc_iucv_notifier_add,
 	.notifier_del = hvc_iucv_notifier_del,
 	.notifier_hangup = hvc_iucv_notifier_hangup,
+	.dtr_rts = hvc_iucv_dtr_rts,
 };
 
 /* Suspend / resume device operations */
@@ -947,6 +1064,25 @@
 	.pm   = &hvc_iucv_pm_ops,
 };
 
+/* IUCV HVC device attributes */
+static DEVICE_ATTR(termid, 0640, hvc_iucv_dev_termid_show, NULL);
+static DEVICE_ATTR(state, 0640, hvc_iucv_dev_state_show, NULL);
+static DEVICE_ATTR(peer, 0640, hvc_iucv_dev_peer_show, NULL);
+static struct attribute *hvc_iucv_dev_attrs[] = {
+	&dev_attr_termid.attr,
+	&dev_attr_state.attr,
+	&dev_attr_peer.attr,
+	NULL,
+};
+static struct attribute_group hvc_iucv_dev_attr_group = {
+	.attrs = hvc_iucv_dev_attrs,
+};
+static const struct attribute_group *hvc_iucv_dev_attr_groups[] = {
+	&hvc_iucv_dev_attr_group,
+	NULL,
+};
+
+
 /**
  * hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance
  * @id:			hvc_iucv_table index
@@ -1008,6 +1144,7 @@
 	priv->dev->bus = &iucv_bus;
 	priv->dev->parent = iucv_root;
 	priv->dev->driver = &hvc_iucv_driver;
+	priv->dev->groups = hvc_iucv_dev_attr_groups;
 	priv->dev->release = (void (*)(struct device *)) kfree;
 	rc = device_register(priv->dev);
 	if (rc) {
@@ -1041,6 +1178,7 @@
 /**
  * hvc_iucv_parse_filter() - Parse filter for a single z/VM user ID
  * @filter:	String containing a comma-separated list of z/VM user IDs
+ * @dest:	Location where to store the parsed z/VM user ID
  */
 static const char *hvc_iucv_parse_filter(const char *filter, char *dest)
 {
@@ -1063,6 +1201,10 @@
 	if (filter[len - 1] == '\n')
 		len--;
 
+	/* prohibit filter entries containing the wildcard character only */
+	if (len == 1 && *filter == FILTER_WILDCARD_CHAR)
+		return ERR_PTR(-EINVAL);
+
 	if (len > 8)
 		return ERR_PTR(-EINVAL);
 
@@ -1203,7 +1345,7 @@
 
 #define param_check_vmidfilter(name, p) __param_check(name, p, void)
 
-static struct kernel_param_ops param_ops_vmidfilter = {
+static const struct kernel_param_ops param_ops_vmidfilter = {
 	.set = param_set_vmidfilter,
 	.get = param_get_vmidfilter,
 };
@@ -1316,8 +1458,7 @@
 	mempool_destroy(hvc_iucv_mempool);
 	kmem_cache_destroy(hvc_iucv_buffer_cache);
 out_error:
-	if (hvc_iucv_filter)
-		kfree(hvc_iucv_filter);
+	kfree(hvc_iucv_filter);
 	hvc_iucv_devices = 0; /* ensure that we do not provide any device */
 	return rc;
 }
@@ -1328,7 +1469,7 @@
  */
 static	int __init hvc_iucv_config(char *val)
 {
-	 return strict_strtoul(val, 10, &hvc_iucv_devices);
+	 return kstrtoul(val, 10, &hvc_iucv_devices);
 }