Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

2 files changed, 465 insertions, 0 deletions

diff --git a/include/net/iucv/af_iucv.h b/include/net/iucv/af_iucv.h
new file mode 100644
index 000000000..df85d19fb
--- /dev/null
+++ b/include/net/iucv/af_iucv.h
@@ -0,0 +1,164 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2006 IBM Corporation
+ * IUCV protocol stack for Linux on zSeries
+ * Version 1.0
+ * Author(s): Jennifer Hunt <jenhunt@us.ibm.com>
+ *
+ */
+
+#ifndef __AFIUCV_H
+#define __AFIUCV_H
+
+#include <asm/types.h>
+#include <asm/byteorder.h>
+#include <linux/list.h>
+#include <linux/poll.h>
+#include <linux/socket.h>
+#include <net/iucv/iucv.h>
+
+#ifndef AF_IUCV
+#define AF_IUCV		32
+#define PF_IUCV		AF_IUCV
+#endif
+
+/* Connection and socket states */
+enum {
+	IUCV_CONNECTED = 1,
+	IUCV_OPEN,
+	IUCV_BOUND,
+	IUCV_LISTEN,
+	IUCV_DISCONN,
+	IUCV_CLOSING,
+	IUCV_CLOSED
+};
+
+#define IUCV_QUEUELEN_DEFAULT	65535
+#define IUCV_HIPER_MSGLIM_DEFAULT	128
+#define IUCV_CONN_TIMEOUT	(HZ * 40)
+#define IUCV_DISCONN_TIMEOUT	(HZ * 2)
+#define IUCV_CONN_IDLE_TIMEOUT	(HZ * 60)
+#define IUCV_BUFSIZE_DEFAULT	32768
+
+/* IUCV socket address */
+struct sockaddr_iucv {
+	sa_family_t	siucv_family;
+	unsigned short	siucv_port;		/* Reserved */
+	unsigned int	siucv_addr;		/* Reserved */
+	char		siucv_nodeid[8];	/* Reserved */
+	char		siucv_user_id[8];	/* Guest User Id */
+	char		siucv_name[8];		/* Application Name */
+};
+
+
+/* Common socket structures and functions */
+struct sock_msg_q {
+	struct iucv_path	*path;
+	struct iucv_message	msg;
+	struct list_head	list;
+	spinlock_t		lock;
+};
+
+#define AF_IUCV_FLAG_ACK 0x1
+#define AF_IUCV_FLAG_SYN 0x2
+#define AF_IUCV_FLAG_FIN 0x4
+#define AF_IUCV_FLAG_WIN 0x8
+#define AF_IUCV_FLAG_SHT 0x10
+
+struct af_iucv_trans_hdr {
+	u16 magic;
+	u8 version;
+	u8 flags;
+	u16 window;
+	char destNodeID[8];
+	char destUserID[8];
+	char destAppName[16];
+	char srcNodeID[8];
+	char srcUserID[8];
+	char srcAppName[16];             /* => 70 bytes */
+	struct iucv_message iucv_hdr;    /* => 33 bytes */
+	u8 pad;                          /* total 104 bytes */
+} __packed;
+
+static inline struct af_iucv_trans_hdr *iucv_trans_hdr(struct sk_buff *skb)
+{
+	return (struct af_iucv_trans_hdr *)skb_network_header(skb);
+}
+
+enum iucv_tx_notify {
+	/* transmission of skb is completed and was successful */
+	TX_NOTIFY_OK = 0,
+	/* target is unreachable */
+	TX_NOTIFY_UNREACHABLE = 1,
+	/* transfer pending queue full */
+	TX_NOTIFY_TPQFULL = 2,
+	/* general error */
+	TX_NOTIFY_GENERALERROR = 3,
+	/* transmission of skb is pending - may interleave
+	 * with TX_NOTIFY_DELAYED_* */
+	TX_NOTIFY_PENDING = 4,
+	/* transmission of skb was done successfully (delayed) */
+	TX_NOTIFY_DELAYED_OK = 5,
+	/* target unreachable (detected delayed) */
+	TX_NOTIFY_DELAYED_UNREACHABLE = 6,
+	/* general error (detected delayed) */
+	TX_NOTIFY_DELAYED_GENERALERROR = 7,
+};
+
+#define iucv_sk(__sk) ((struct iucv_sock *) __sk)
+
+#define AF_IUCV_TRANS_IUCV 0
+#define AF_IUCV_TRANS_HIPER 1
+
+struct iucv_sock {
+	struct sock		sk;
+	struct_group(init,
+		char		src_user_id[8];
+		char		src_name[8];
+		char		dst_user_id[8];
+		char		dst_name[8];
+	);
+	struct list_head	accept_q;
+	spinlock_t		accept_q_lock;
+	struct sock		*parent;
+	struct iucv_path	*path;
+	struct net_device	*hs_dev;
+	struct sk_buff_head	send_skb_q;
+	struct sk_buff_head	backlog_skb_q;
+	struct sock_msg_q	message_q;
+	unsigned int		send_tag;
+	u8			flags;
+	u16			msglimit;
+	u16			msglimit_peer;
+	atomic_t		skbs_in_xmit;
+	atomic_t		msg_sent;
+	atomic_t		msg_recv;
+	atomic_t		pendings;
+	int			transport;
+	void			(*sk_txnotify)(struct sock *sk,
+					       enum iucv_tx_notify n);
+};
+
+struct iucv_skb_cb {
+	u32	class;		/* target class of message */
+	u32	tag;		/* tag associated with message */
+	u32	offset;		/* offset for skb receival */
+};
+
+#define IUCV_SKB_CB(__skb)	((struct iucv_skb_cb *)&((__skb)->cb[0]))
+
+/* iucv socket options (SOL_IUCV) */
+#define SO_IPRMDATA_MSG	0x0080		/* send/recv IPRM_DATA msgs */
+#define SO_MSGLIMIT	0x1000		/* get/set IUCV MSGLIMIT */
+#define SO_MSGSIZE	0x0800		/* get maximum msgsize */
+
+/* iucv related control messages (scm) */
+#define SCM_IUCV_TRGCLS	0x0001		/* target class control message */
+
+struct iucv_sock_list {
+	struct hlist_head head;
+	rwlock_t	  lock;
+	atomic_t	  autobind_name;
+};
+
+#endif /* __IUCV_H */
diff --git a/include/net/iucv/iucv.h b/include/net/iucv/iucv.h
new file mode 100644
index 000000000..18f511da9
--- /dev/null
+++ b/include/net/iucv/iucv.h
@@ -0,0 +1,301 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  drivers/s390/net/iucv.h
+ *    IUCV base support.
+ *
+ *  S390 version
+ *    Copyright 2000, 2006 IBM Corporation
+ *    Author(s):Alan Altmark (Alan_Altmark@us.ibm.com)
+ *		Xenia Tkatschow (xenia@us.ibm.com)
+ *    Rewritten for af_iucv:
+ *	Martin Schwidefsky <schwidefsky@de.ibm.com>
+ *
+ *
+ * Functionality:
+ * To explore any of the IUCV functions, one must first register their
+ * program using iucv_register(). Once your program has successfully
+ * completed a register, it can exploit the other functions.
+ * For further reference on all IUCV functionality, refer to the
+ * CP Programming Services book, also available on the web thru
+ * www.vm.ibm.com/pubs, manual # SC24-6084
+ *
+ * Definition of Return Codes
+ * - All positive return codes including zero are reflected back
+ *   from CP. The definition of each return code can be found in
+ *   CP Programming Services book.
+ * - Return Code of:
+ *   -EINVAL: Invalid value
+ *   -ENOMEM: storage allocation failed
+ */
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <asm/dma-types.h>
+#include <asm/debug.h>
+
+/*
+ * IUCV option flags usable by device drivers:
+ *
+ * IUCV_IPRMDATA  Indicates that your program can handle a message in the
+ *		  parameter list / a message is sent in the parameter list.
+ *		  Used for iucv_path_accept, iucv_path_connect,
+ *		  iucv_message_reply, iucv_message_send, iucv_message_send2way.
+ * IUCV_IPQUSCE	  Indicates that you do not want to receive messages on this
+ *		  path until an iucv_path_resume is issued.
+ *		  Used for iucv_path_accept, iucv_path_connect.
+ * IUCV_IPBUFLST  Indicates that an address list is used for the message data.
+ *		  Used for iucv_message_receive, iucv_message_send,
+ *		  iucv_message_send2way.
+ * IUCV_IPPRTY	  Specifies that you want to send priority messages.
+ *		  Used for iucv_path_accept, iucv_path_connect,
+ *		  iucv_message_reply, iucv_message_send, iucv_message_send2way.
+ * IUCV_IPSYNC	  Indicates a synchronous send request.
+ *		  Used for iucv_message_send, iucv_message_send2way.
+ * IUCV_IPANSLST  Indicates that an address list is used for the reply data.
+ *		  Used for iucv_message_reply, iucv_message_send2way.
+ * IUCV_IPLOCAL	  Specifies that the communication partner has to be on the
+ *		  local system. If local is specified no target class can be
+ *		  specified.
+ *		  Used for iucv_path_connect.
+ *
+ * All flags are defined in the input field IPFLAGS1 of each function
+ * and can be found in CP Programming Services.
+ */
+#define IUCV_IPRMDATA	0x80
+#define IUCV_IPQUSCE	0x40
+#define IUCV_IPBUFLST	0x40
+#define IUCV_IPPRTY	0x20
+#define IUCV_IPANSLST	0x08
+#define IUCV_IPSYNC	0x04
+#define IUCV_IPLOCAL	0x01
+
+/*
+ * iucv_array : Defines buffer array.
+ * Inside the array may be 31- bit addresses and 31-bit lengths.
+ * Use a pointer to an iucv_array as the buffer, reply or answer
+ * parameter on iucv_message_send, iucv_message_send2way, iucv_message_receive
+ * and iucv_message_reply if IUCV_IPBUFLST or IUCV_IPANSLST are used.
+ */
+struct iucv_array {
+	dma32_t address;
+	u32 length;
+} __attribute__ ((aligned (8)));
+
+extern const struct bus_type iucv_bus;
+
+struct device_driver;
+
+struct device *iucv_alloc_device(const struct attribute_group **attrs,
+				 struct device_driver *driver, void *priv,
+				 const char *fmt, ...) __printf(4, 5);
+
+/*
+ * struct iucv_path
+ * pathid: 16 bit path identification
+ * msglim: 16 bit message limit
+ * flags: properties of the path: IPRMDATA, IPQUSCE, IPPRTY
+ * handler:  address of iucv handler structure
+ * private: private information of the handler associated with the path
+ * list: list_head for the iucv_handler path list.
+ */
+struct iucv_path {
+	u16 pathid;
+	u16 msglim;
+	u8  flags;
+	void *private;
+	struct iucv_handler *handler;
+	struct list_head list;
+};
+
+/*
+ * struct iucv_message
+ * id: 32 bit message id
+ * audit: 32 bit error information of purged or replied messages
+ * class: 32 bit target class of a message (source class for replies)
+ * tag: 32 bit tag to be associated with the message
+ * length: 32 bit length of the message / reply
+ * reply_size: 32 bit maximum allowed length of the reply
+ * rmmsg: 8 byte inline message
+ * flags: message properties (IUCV_IPPRTY)
+ */
+struct iucv_message {
+	u32 id;
+	u32 audit;
+	u32 class;
+	u32 tag;
+	u32 length;
+	u32 reply_size;
+	u8  rmmsg[8];
+	u8  flags;
+} __packed;
+
+/*
+ * struct iucv_handler
+ *
+ * A vector of functions that handle IUCV interrupts. Each functions gets
+ * a parameter area as defined by the CP Programming Services and private
+ * pointer that is provided by the user of the interface.
+ */
+struct iucv_handler {
+	 /*
+	  * The path_pending function is called after an iucv interrupt
+	  * type 0x01 has been received. The base code allocates a path
+	  * structure and "asks" the handler if this path belongs to the
+	  * handler. To accept the path the path_pending function needs
+	  * to call iucv_path_accept and return 0. If the callback returns
+	  * a value != 0 the iucv base code will continue with the next
+	  * handler. The order in which the path_pending functions are
+	  * called is the order of the registration of the iucv handlers
+	  * to the base code.
+	  */
+	int  (*path_pending)(struct iucv_path *, u8 *ipvmid, u8 *ipuser);
+	/*
+	 * The path_complete function is called after an iucv interrupt
+	 * type 0x02 has been received for a path that has been established
+	 * for this handler with iucv_path_connect and got accepted by the
+	 * peer with iucv_path_accept.
+	 */
+	void (*path_complete)(struct iucv_path *, u8 *ipuser);
+	 /*
+	  * The path_severed function is called after an iucv interrupt
+	  * type 0x03 has been received. The communication peer shutdown
+	  * his end of the communication path. The path still exists and
+	  * remaining messages can be received until a iucv_path_sever
+	  * shuts down the other end of the path as well.
+	  */
+	void (*path_severed)(struct iucv_path *, u8 *ipuser);
+	/*
+	 * The path_quiesced function is called after an icuv interrupt
+	 * type 0x04 has been received. The communication peer has quiesced
+	 * the path. Delivery of messages is stopped until iucv_path_resume
+	 * has been called.
+	 */
+	void (*path_quiesced)(struct iucv_path *, u8 *ipuser);
+	/*
+	 * The path_resumed function is called after an icuv interrupt
+	 * type 0x05 has been received. The communication peer has resumed
+	 * the path.
+	 */
+	void (*path_resumed)(struct iucv_path *, u8 *ipuser);
+	/*
+	 * The message_pending function is called after an icuv interrupt
+	 * type 0x06 or type 0x07 has been received. A new message is
+	 * available and can be received with iucv_message_receive.
+	 */
+	void (*message_pending)(struct iucv_path *, struct iucv_message *);
+	/*
+	 * The message_complete function is called after an icuv interrupt
+	 * type 0x08 or type 0x09 has been received. A message send with
+	 * iucv_message_send2way has been replied to. The reply can be
+	 * received with iucv_message_receive.
+	 */
+	void (*message_complete)(struct iucv_path *, struct iucv_message *);
+
+	struct list_head list;
+	struct list_head paths;
+};
+
+int iucv_register(struct iucv_handler *handler, int smp);
+void iucv_unregister(struct iucv_handler *handler, int smp);
+
+/**
+ * iucv_path_alloc - Allocate a new path structure for use with iucv_connect.
+ * @msglim: initial message limit
+ * @flags: initial flags
+ * @gfp: kmalloc allocation flag
+ *
+ * Returns: NULL if the memory allocation failed or a pointer to the
+ * path structure.
+ */
+static inline struct iucv_path *iucv_path_alloc(u16 msglim, u8 flags, gfp_t gfp)
+{
+	struct iucv_path *path;
+
+	path = kzalloc_obj(struct iucv_path, gfp);
+	if (path) {
+		path->msglim = msglim;
+		path->flags = flags;
+	}
+	return path;
+}
+
+/**
+ * iucv_path_free - Frees a path structure.
+ * @path: address of iucv path structure
+ */
+static inline void iucv_path_free(struct iucv_path *path)
+{
+	kfree(path);
+}
+
+int iucv_path_accept(struct iucv_path *path, struct iucv_handler *handler,
+		     u8 *userdata, void *private);
+
+int iucv_path_connect(struct iucv_path *path, struct iucv_handler *handler,
+		      u8 *userid, u8 *system, u8 *userdata,
+		      void *private);
+
+int iucv_path_quiesce(struct iucv_path *path, u8 *userdata);
+
+int iucv_path_resume(struct iucv_path *path, u8 *userdata);
+
+int iucv_path_sever(struct iucv_path *path, u8 *userdata);
+
+int iucv_message_purge(struct iucv_path *path, struct iucv_message *msg,
+		       u32 srccls);
+
+int iucv_message_receive(struct iucv_path *path, struct iucv_message *msg,
+			 u8 flags, void *buffer, size_t size, size_t *residual);
+
+int __iucv_message_receive(struct iucv_path *path, struct iucv_message *msg,
+			   u8 flags, void *buffer, size_t size,
+			   size_t *residual);
+
+int iucv_message_reject(struct iucv_path *path, struct iucv_message *msg);
+
+int iucv_message_reply(struct iucv_path *path, struct iucv_message *msg,
+		       u8 flags, void *reply, size_t size);
+
+int iucv_message_send(struct iucv_path *path, struct iucv_message *msg,
+		      u8 flags, u32 srccls, void *buffer, size_t size);
+
+int __iucv_message_send(struct iucv_path *path, struct iucv_message *msg,
+			u8 flags, u32 srccls, void *buffer, size_t size);
+
+int iucv_message_send2way(struct iucv_path *path, struct iucv_message *msg,
+			  u8 flags, u32 srccls, void *buffer, size_t size,
+			  void *answer, size_t asize, size_t *residual);
+
+struct iucv_interface {
+	int (*message_receive)(struct iucv_path *path, struct iucv_message *msg,
+		u8 flags, void *buffer, size_t size, size_t *residual);
+	int (*__message_receive)(struct iucv_path *path,
+		struct iucv_message *msg, u8 flags, void *buffer, size_t size,
+		size_t *residual);
+	int (*message_reply)(struct iucv_path *path, struct iucv_message *msg,
+		u8 flags, void *reply, size_t size);
+	int (*message_reject)(struct iucv_path *path, struct iucv_message *msg);
+	int (*message_send)(struct iucv_path *path, struct iucv_message *msg,
+		u8 flags, u32 srccls, void *buffer, size_t size);
+	int (*__message_send)(struct iucv_path *path, struct iucv_message *msg,
+		u8 flags, u32 srccls, void *buffer, size_t size);
+	int (*message_send2way)(struct iucv_path *path,
+		struct iucv_message *msg, u8 flags, u32 srccls, void *buffer,
+		size_t size, void *answer, size_t asize, size_t *residual);
+	int (*message_purge)(struct iucv_path *path, struct iucv_message *msg,
+		u32 srccls);
+	int (*path_accept)(struct iucv_path *path, struct iucv_handler *handler,
+		u8 userdata[16], void *private);
+	int (*path_connect)(struct iucv_path *path,
+		struct iucv_handler *handler,
+		u8 userid[8], u8 system[8], u8 userdata[16], void *private);
+	int (*path_quiesce)(struct iucv_path *path, u8 userdata[16]);
+	int (*path_resume)(struct iucv_path *path, u8 userdata[16]);
+	int (*path_sever)(struct iucv_path *path, u8 userdata[16]);
+	int (*iucv_register)(struct iucv_handler *handler, int smp);
+	void (*iucv_unregister)(struct iucv_handler *handler, int smp);
+	const struct bus_type *bus;
+	struct device *root;
+};
+
+extern struct iucv_interface iucv_if;