[lttng-modules.git] / lttng-statedump-impl.c

/*
 * lttng-statedump.c
 *
 * Linux Trace Toolkit Next Generation Kernel State Dump
 *
 * Copyright 2005 Jean-Hugues Deschenes <jean-hugues.deschenes@polymtl.ca>
 * Copyright 2006-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; only
 * version 2.1 of the License.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * Changes:
 *	Eric Clement:                   Add listing of network IP interface
 *	2006, 2007 Mathieu Desnoyers	Fix kernel threads
 *	                                Various updates
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/netlink.h>
#include <linux/inet.h>
#include <linux/ip.h>
#include <linux/kthread.h>
#include <linux/proc_fs.h>
#include <linux/file.h>
#include <linux/interrupt.h>
#include <linux/irqnr.h>
#include <linux/cpu.h>
#include <linux/netdevice.h>
#include <linux/inetdevice.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/fdtable.h>
#include <linux/swap.h>
#include <linux/wait.h>
#include <linux/mutex.h>

#include "lttng-events.h"
#include "wrapper/irqdesc.h"

#ifdef CONFIG_GENERIC_HARDIRQS
#include <linux/irq.h>
#endif

/* Define the tracepoints, but do not build the probes */
#define CREATE_TRACE_POINTS
#define TRACE_INCLUDE_PATH ../instrumentation/events/lttng-module
#define TRACE_INCLUDE_FILE lttng-statedump
#include "instrumentation/events/lttng-module/lttng-statedump.h"

/*
 * Protected by the trace lock.
 */
static struct delayed_work cpu_work[NR_CPUS];
static DECLARE_WAIT_QUEUE_HEAD(statedump_wq);
static atomic_t kernel_threads_to_run;

enum lttng_thread_type {
	LTTNG_USER_THREAD = 0,
	LTTNG_KERNEL_THREAD = 1,
};

enum lttng_execution_mode {
	LTTNG_USER_MODE = 0,
	LTTNG_SYSCALL = 1,
	LTTNG_TRAP = 2,
	LTTNG_IRQ = 3,
	LTTNG_SOFTIRQ = 4,
	LTTNG_MODE_UNKNOWN = 5,
};

enum lttng_execution_submode {
	LTTNG_NONE = 0,
	LTTNG_UNKNOWN = 1,
};

enum lttng_process_status {
	LTTNG_UNNAMED = 0,
	LTTNG_WAIT_FORK = 1,
	LTTNG_WAIT_CPU = 2,
	LTTNG_EXIT = 3,
	LTTNG_ZOMBIE = 4,
	LTTNG_WAIT = 5,
	LTTNG_RUN = 6,
	LTTNG_DEAD = 7,
};

#ifdef CONFIG_INET
static
void lttng_enumerate_device(struct lttng_session *session,
		struct net_device *dev)
{
	struct in_device *in_dev;
	struct in_ifaddr *ifa;

	if (dev->flags & IFF_UP) {
		in_dev = in_dev_get(dev);
		if (in_dev) {
			for (ifa = in_dev->ifa_list; ifa != NULL;
			     ifa = ifa->ifa_next) {
				trace_lttng_statedump_network_interface(
					session, dev, ifa);
			}
			in_dev_put(in_dev);
		}
	} else {
		trace_lttng_statedump_network_interface(
			session, dev, NULL);
	}
}

static
int lttng_enumerate_network_ip_interface(struct lttng_session *session)
{
	struct net_device *dev;

	read_lock(&dev_base_lock);
	for_each_netdev(&init_net, dev)
		lttng_enumerate_device(session, dev);
	read_unlock(&dev_base_lock);

	return 0;
}
#else /* CONFIG_INET */
static inline
int lttng_enumerate_network_ip_interface(struct lttng_session *session)
{
	return 0;
}
#endif /* CONFIG_INET */


static
void lttng_enumerate_task_fd(struct lttng_session *session,
		struct task_struct *p, char *tmp)
{
	struct fdtable *fdt;
	struct file *filp;
	unsigned int i;
	const unsigned char *path;

	task_lock(p);
	if (!p->files)
		goto unlock_task;
	spin_lock(&p->files->file_lock);
	fdt = files_fdtable(p->files);
	for (i = 0; i < fdt->max_fds; i++) {
		filp = fcheck_files(p->files, i);
		if (!filp)
			continue;
		path = d_path(&filp->f_path, tmp, PAGE_SIZE);
		/* Make sure we give at least some info */
		trace_lttng_statedump_file_descriptor(session, p, i,
			IS_ERR(path) ?
				filp->f_dentry->d_name.name :
				path);
	}
	spin_unlock(&p->files->file_lock);
unlock_task:
	task_unlock(p);
}

static
int lttng_enumerate_file_descriptors(struct lttng_session *session)
{
	struct task_struct *p;
	char *tmp = (char *) __get_free_page(GFP_KERNEL);

	/* Enumerate active file descriptors */
	rcu_read_lock();
	for_each_process(p)
		lttng_enumerate_task_fd(session, p, tmp);
	rcu_read_unlock();
	free_page((unsigned long) tmp);
	return 0;
}

static
void lttng_enumerate_task_vm_maps(struct lttng_session *session,
		struct task_struct *p)
{
	struct mm_struct *mm;
	struct vm_area_struct *map;
	unsigned long ino;

	/* get_task_mm does a task_lock... */
	mm = get_task_mm(p);
	if (!mm)
		return;

	map = mm->mmap;
	if (map) {
		down_read(&mm->mmap_sem);
		while (map) {
			if (map->vm_file)
				ino = map->vm_file->f_dentry->d_inode->i_ino;
			else
				ino = 0;
			trace_lttng_statedump_vm_map(session, p, map, ino);
			map = map->vm_next;
		}
		up_read(&mm->mmap_sem);
	}
	mmput(mm);
}

static
int lttng_enumerate_vm_maps(struct lttng_session *session)
{
	struct task_struct *p;

	rcu_read_lock();
	for_each_process(p)
		lttng_enumerate_task_vm_maps(session, p);
	rcu_read_unlock();
	return 0;
}

#ifdef CONFIG_GENERIC_HARDIRQS

#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,39))
#define irq_desc_get_chip(desc) get_irq_desc_chip(desc)
#endif

static
void lttng_list_interrupts(struct lttng_session *session)
{
	unsigned int irq;
	unsigned long flags = 0;
	struct irq_desc *desc;

#define irq_to_desc	wrapper_irq_to_desc
	/* needs irq_desc */
	for_each_irq_desc(irq, desc) {
		struct irqaction *action;
		const char *irq_chip_name =
			irq_desc_get_chip(desc)->name ? : "unnamed_irq_chip";

		local_irq_save(flags);
		raw_spin_lock(&desc->lock);
		for (action = desc->action; action; action = action->next) {
			trace_lttng_statedump_interrupt(session,
				irq, irq_chip_name, action);
		}
		raw_spin_unlock(&desc->lock);
		local_irq_restore(flags);
	}
#undef irq_to_desc
}
#else
static inline
void list_interrupts(struct lttng_session *session)
{
}
#endif

static
int lttng_enumerate_process_states(struct lttng_session *session)
{
	struct task_struct *g, *p;

	rcu_read_lock();
	for_each_process(g) {
		p = g;
		do {
			enum lttng_execution_mode mode =
				LTTNG_MODE_UNKNOWN;
			enum lttng_execution_submode submode =
				LTTNG_UNKNOWN;
			enum lttng_process_status status;
			enum lttng_thread_type type;

			task_lock(p);
			if (p->exit_state == EXIT_ZOMBIE)
				status = LTTNG_ZOMBIE;
			else if (p->exit_state == EXIT_DEAD)
				status = LTTNG_DEAD;
			else if (p->state == TASK_RUNNING) {
				/* Is this a forked child that has not run yet? */
				if (list_empty(&p->rt.run_list))
					status = LTTNG_WAIT_FORK;
				else
					/*
					 * All tasks are considered as wait_cpu;
					 * the viewer will sort out if the task
					 * was really running at this time.
					 */
					status = LTTNG_WAIT_CPU;
			} else if (p->state &
				(TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)) {
				/* Task is waiting for something to complete */
				status = LTTNG_WAIT;
			} else
				status = LTTNG_UNNAMED;
			submode = LTTNG_NONE;

			/*
			 * Verification of t->mm is to filter out kernel
			 * threads; Viewer will further filter out if a
			 * user-space thread was in syscall mode or not.
			 */
			if (p->mm)
				type = LTTNG_USER_THREAD;
			else
				type = LTTNG_KERNEL_THREAD;
			trace_lttng_statedump_process_state(session,
				p, type, mode, submode, status);
			task_unlock(p);
		} while_each_thread(g, p);
	}
	rcu_read_unlock();

	return 0;
}

static
void lttng_statedump_work_func(struct work_struct *work)
{
	if (atomic_dec_and_test(&kernel_threads_to_run))
		/* If we are the last thread, wake up do_lttng_statedump */
		wake_up(&statedump_wq);
}

static
int do_lttng_statedump(struct lttng_session *session)
{
	int cpu;

	printk(KERN_DEBUG "LTT state dump thread start\n");
	trace_lttng_statedump_start(session);
	lttng_enumerate_process_states(session);
	lttng_enumerate_file_descriptors(session);
	lttng_enumerate_vm_maps(session);
	lttng_list_interrupts(session);
	lttng_enumerate_network_ip_interface(session);

	/* TODO lttng_dump_idt_table(session); */
	/* TODO lttng_dump_softirq_vec(session); */
	/* TODO lttng_list_modules(session); */
	/* TODO lttng_dump_swap_files(session); */

	/*
	 * Fire off a work queue on each CPU. Their sole purpose in life
	 * is to guarantee that each CPU has been in a state where is was in
	 * syscall mode (i.e. not in a trap, an IRQ or a soft IRQ).
	 */
	get_online_cpus();
	atomic_set(&kernel_threads_to_run, num_online_cpus());
	for_each_online_cpu(cpu) {
		INIT_DELAYED_WORK(&cpu_work[cpu], lttng_statedump_work_func);
		schedule_delayed_work_on(cpu, &cpu_work[cpu], 0);
	}
	/* Wait for all threads to run */
	__wait_event(statedump_wq, (atomic_read(&kernel_threads_to_run) != 0));
	put_online_cpus();
	/* Our work is done */
	printk(KERN_DEBUG "LTT state dump end\n");
	trace_lttng_statedump_end(session);
	return 0;
}

/*
 * Called with session mutex held.
 */
int lttng_statedump_start(struct lttng_session *session)
{
	printk(KERN_DEBUG "LTTng: state dump begin\n");
	return do_lttng_statedump(session);
}
EXPORT_SYMBOL_GPL(lttng_statedump_start);

MODULE_LICENSE("GPL and additional rights");
MODULE_AUTHOR("Jean-Hugues Deschenes");
MODULE_DESCRIPTION("Linux Trace Toolkit Next Generation Statedump");
Commit	Line	Data
c337ddc2	1	/*
886d51a3 MD	2	* lttng-statedump.c
886d51a3 MD	3	*
c337ddc2 MD	4	* Linux Trace Toolkit Next Generation Kernel State Dump
	5	*
	6	* Copyright 2005 Jean-Hugues Deschenes <jean-hugues.deschenes@polymtl.ca>
	7	* Copyright 2006-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	8	*
886d51a3 MD	9	* This library is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU Lesser General Public
	11	* License as published by the Free Software Foundation; only
	12	* version 2.1 of the License.
	13	*
	14	* This library is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	17	* Lesser General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU Lesser General Public
	20	* License along with this library; if not, write to the Free Software
	21	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	22	*
c337ddc2 MD	23	* Changes:
	24	* Eric Clement: Add listing of network IP interface
	25	* 2006, 2007 Mathieu Desnoyers Fix kernel threads
	26	* Various updates
c337ddc2 MD	27	*/
	28
	29	#include <linux/init.h>
	30	#include <linux/module.h>
	31	#include <linux/netlink.h>
	32	#include <linux/inet.h>
	33	#include <linux/ip.h>
	34	#include <linux/kthread.h>
	35	#include <linux/proc_fs.h>
	36	#include <linux/file.h>
	37	#include <linux/interrupt.h>
	38	#include <linux/irqnr.h>
	39	#include <linux/cpu.h>
	40	#include <linux/netdevice.h>
	41	#include <linux/inetdevice.h>
	42	#include <linux/sched.h>
	43	#include <linux/mm.h>
	44	#include <linux/fdtable.h>
	45	#include <linux/swap.h>
	46	#include <linux/wait.h>
	47	#include <linux/mutex.h>
	48
	49	#include "lttng-events.h"
	50	#include "wrapper/irqdesc.h"
	51
	52	#ifdef CONFIG_GENERIC_HARDIRQS
	53	#include <linux/irq.h>
	54	#endif
	55
	56	/* Define the tracepoints, but do not build the probes */
	57	#define CREATE_TRACE_POINTS
	58	#define TRACE_INCLUDE_PATH ../instrumentation/events/lttng-module
	59	#define TRACE_INCLUDE_FILE lttng-statedump
	60	#include "instrumentation/events/lttng-module/lttng-statedump.h"
	61
	62	/*
	63	* Protected by the trace lock.
	64	*/
	65	static struct delayed_work cpu_work[NR_CPUS];
	66	static DECLARE_WAIT_QUEUE_HEAD(statedump_wq);
	67	static atomic_t kernel_threads_to_run;
	68
	69	enum lttng_thread_type {
	70	LTTNG_USER_THREAD = 0,
	71	LTTNG_KERNEL_THREAD = 1,
	72	};
	73
	74	enum lttng_execution_mode {
	75	LTTNG_USER_MODE = 0,
	76	LTTNG_SYSCALL = 1,
	77	LTTNG_TRAP = 2,
	78	LTTNG_IRQ = 3,
	79	LTTNG_SOFTIRQ = 4,
	80	LTTNG_MODE_UNKNOWN = 5,
	81	};
	82
	83	enum lttng_execution_submode {
	84	LTTNG_NONE = 0,
	85	LTTNG_UNKNOWN = 1,
	86	};
	87
	88	enum lttng_process_status {
	89	LTTNG_UNNAMED = 0,
	90	LTTNG_WAIT_FORK = 1,
91	LTTNG_WAIT_CPU = 2,
92	LTTNG_EXIT = 3,
93	LTTNG_ZOMBIE = 4,
94	LTTNG_WAIT = 5,
95	LTTNG_RUN = 6,
96	LTTNG_DEAD = 7,
97	};
98
99	#ifdef CONFIG_INET
100	static
101	void lttng_enumerate_device(struct lttng_session *session,
102	struct net_device *dev)
103	{
104	struct in_device *in_dev;
105	struct in_ifaddr *ifa;
106
107	if (dev->flags & IFF_UP) {
108	in_dev = in_dev_get(dev);
109	if (in_dev) {
110	for (ifa = in_dev->ifa_list; ifa != NULL;
111	ifa = ifa->ifa_next) {
112	trace_lttng_statedump_network_interface(
113	session, dev, ifa);
114	}
115	in_dev_put(in_dev);
116	}
117	} else {
118	trace_lttng_statedump_network_interface(
119	session, dev, NULL);
120	}
121	}
122
123	static
124	int lttng_enumerate_network_ip_interface(struct lttng_session *session)
125	{
126	struct net_device *dev;
127
128	read_lock(&dev_base_lock);
129	for_each_netdev(&init_net, dev)
130	lttng_enumerate_device(session, dev);
131	read_unlock(&dev_base_lock);
132
133	return 0;
134	}
135	#else /* CONFIG_INET */
136	static inline
137	int lttng_enumerate_network_ip_interface(struct lttng_session *session)
138	{
139	return 0;
140	}
141	#endif /* CONFIG_INET */
142
143
144	static
145	void lttng_enumerate_task_fd(struct lttng_session *session,
146	struct task_struct p, char tmp)
147	{
148	struct fdtable *fdt;
149	struct file *filp;
150	unsigned int i;
151	const unsigned char *path;
152
153	task_lock(p);
154	if (!p->files)
155	goto unlock_task;
156	spin_lock(&p->files->file_lock);
157	fdt = files_fdtable(p->files);
158	for (i = 0; i < fdt->max_fds; i++) {
159	filp = fcheck_files(p->files, i);
160	if (!filp)
161	continue;
162	path = d_path(&filp->f_path, tmp, PAGE_SIZE);
163	/* Make sure we give at least some info */
164	trace_lttng_statedump_file_descriptor(session, p, i,
165	IS_ERR(path) ?
166	filp->f_dentry->d_name.name :
167	path);
168	}
169	spin_unlock(&p->files->file_lock);
170	unlock_task:
171	task_unlock(p);
172	}
173
174	static
175	int lttng_enumerate_file_descriptors(struct lttng_session *session)
176	{
177	struct task_struct *p;
178	char tmp = (char ) __get_free_page(GFP_KERNEL);
179
180	/* Enumerate active file descriptors */
181	rcu_read_lock();
182	for_each_process(p)
183	lttng_enumerate_task_fd(session, p, tmp);
184	rcu_read_unlock();
185	free_page((unsigned long) tmp);
186	return 0;
187	}
188
189	static
190	void lttng_enumerate_task_vm_maps(struct lttng_session *session,
191	struct task_struct *p)
192	{
193	struct mm_struct *mm;
194	struct vm_area_struct *map;
195	unsigned long ino;
196
197	/* get_task_mm does a task_lock... */
198	mm = get_task_mm(p);
199	if (!mm)
200	return;
201
202	map = mm->mmap;
203	if (map) {
204	down_read(&mm->mmap_sem);
205	while (map) {
206	if (map->vm_file)
207	ino = map->vm_file->f_dentry->d_inode->i_ino;
208	else
209	ino = 0;
210	trace_lttng_statedump_vm_map(session, p, map, ino);
211	map = map->vm_next;
212	}
213	up_read(&mm->mmap_sem);
214	}
215	mmput(mm);
216	}
217
218	static
219	int lttng_enumerate_vm_maps(struct lttng_session *session)
220	{
221	struct task_struct *p;
222
223	rcu_read_lock();
224	for_each_process(p)
225	lttng_enumerate_task_vm_maps(session, p);
226	rcu_read_unlock();
227	return 0;
228	}
229
230	#ifdef CONFIG_GENERIC_HARDIRQS
47faec4b JN	231
	232	#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,39))
	233	#define irq_desc_get_chip(desc) get_irq_desc_chip(desc)
	234	#endif
	235
c337ddc2 MD	236	static
	237	void lttng_list_interrupts(struct lttng_session *session)
	238	{
	239	unsigned int irq;
	240	unsigned long flags = 0;
	241	struct irq_desc *desc;
	242
	243	#define irq_to_desc wrapper_irq_to_desc
	244	/* needs irq_desc */
	245	for_each_irq_desc(irq, desc) {
	246	struct irqaction *action;
	247	const char *irq_chip_name =
	248	irq_desc_get_chip(desc)->name ? : "unnamed_irq_chip";
	249
	250	local_irq_save(flags);
	251	raw_spin_lock(&desc->lock);
	252	for (action = desc->action; action; action = action->next) {
	253	trace_lttng_statedump_interrupt(session,
	254	irq, irq_chip_name, action);
	255	}
	256	raw_spin_unlock(&desc->lock);
	257	local_irq_restore(flags);
	258	}
	259	#undef irq_to_desc
	260	}
	261	#else
	262	static inline
	263	void list_interrupts(struct lttng_session *session)
	264	{
	265	}
	266	#endif
	267
	268	static
	269	int lttng_enumerate_process_states(struct lttng_session *session)
	270	{
	271	struct task_struct g, p;
	272
	273	rcu_read_lock();
	274	for_each_process(g) {
	275	p = g;
	276	do {
	277	enum lttng_execution_mode mode =
	278	LTTNG_MODE_UNKNOWN;
	279	enum lttng_execution_submode submode =
	280	LTTNG_UNKNOWN;
	281	enum lttng_process_status status;
	282	enum lttng_thread_type type;
	283
	284	task_lock(p);
	285	if (p->exit_state == EXIT_ZOMBIE)
	286	status = LTTNG_ZOMBIE;
	287	else if (p->exit_state == EXIT_DEAD)
	288	status = LTTNG_DEAD;
	289	else if (p->state == TASK_RUNNING) {
	290	/* Is this a forked child that has not run yet? */
	291	if (list_empty(&p->rt.run_list))
	292	status = LTTNG_WAIT_FORK;
	293	else
	294	/*
	295	* All tasks are considered as wait_cpu;
	296	* the viewer will sort out if the task
	297	* was really running at this time.
	298	*/
	299	status = LTTNG_WAIT_CPU;
300	} else if (p->state &
301	(TASK_INTERRUPTIBLE \| TASK_UNINTERRUPTIBLE)) {
302	/* Task is waiting for something to complete */
303	status = LTTNG_WAIT;
304	} else
305	status = LTTNG_UNNAMED;
306	submode = LTTNG_NONE;
307
308	/*
309	* Verification of t->mm is to filter out kernel
310	* threads; Viewer will further filter out if a
311	* user-space thread was in syscall mode or not.
312	*/
313	if (p->mm)
314	type = LTTNG_USER_THREAD;
315	else
316	type = LTTNG_KERNEL_THREAD;
317	trace_lttng_statedump_process_state(session,
318	p, type, mode, submode, status);
319	task_unlock(p);
320	} while_each_thread(g, p);
321	}
322	rcu_read_unlock();
323
324	return 0;
325	}
326
327	static
328	void lttng_statedump_work_func(struct work_struct *work)
329	{
330	if (atomic_dec_and_test(&kernel_threads_to_run))
331	/* If we are the last thread, wake up do_lttng_statedump */
332	wake_up(&statedump_wq);
333	}
334
335	static
336	int do_lttng_statedump(struct lttng_session *session)
337	{
338	int cpu;
339
340	printk(KERN_DEBUG "LTT state dump thread start\n");
341	trace_lttng_statedump_start(session);
342	lttng_enumerate_process_states(session);
343	lttng_enumerate_file_descriptors(session);
344	lttng_enumerate_vm_maps(session);
345	lttng_list_interrupts(session);
346	lttng_enumerate_network_ip_interface(session);
347
348	/* TODO lttng_dump_idt_table(session); */
349	/* TODO lttng_dump_softirq_vec(session); */
350	/* TODO lttng_list_modules(session); */
351	/* TODO lttng_dump_swap_files(session); */
352
353	/*
354	* Fire off a work queue on each CPU. Their sole purpose in life
355	* is to guarantee that each CPU has been in a state where is was in
356	* syscall mode (i.e. not in a trap, an IRQ or a soft IRQ).
357	*/
358	get_online_cpus();
359	atomic_set(&kernel_threads_to_run, num_online_cpus());
360	for_each_online_cpu(cpu) {
361	INIT_DELAYED_WORK(&cpu_work[cpu], lttng_statedump_work_func);
362	schedule_delayed_work_on(cpu, &cpu_work[cpu], 0);
363	}
364	/* Wait for all threads to run */
365	__wait_event(statedump_wq, (atomic_read(&kernel_threads_to_run) != 0));
366	put_online_cpus();
367	/* Our work is done */
368	printk(KERN_DEBUG "LTT state dump end\n");
369	trace_lttng_statedump_end(session);
370	return 0;
371	}
372
373	/*
374	* Called with session mutex held.
375	*/
376	int lttng_statedump_start(struct lttng_session *session)
377	{
378	printk(KERN_DEBUG "LTTng: state dump begin\n");
379	return do_lttng_statedump(session);
380	}
381	EXPORT_SYMBOL_GPL(lttng_statedump_start);
382
383	MODULE_LICENSE("GPL and additional rights");
384	MODULE_AUTHOR("Jean-Hugues Deschenes");
385	MODULE_DESCRIPTION("Linux Trace Toolkit Next Generation Statedump");