[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"
#include "wrapper/spinlock.h"
#include "wrapper/fdtable.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"

struct lttng_fd_ctx {
	char *page;
	struct lttng_session *session;
	struct task_struct *p;
};

/*
 * 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
int lttng_dump_one_fd(const void *p, struct file *file, unsigned int fd)
{
	const struct lttng_fd_ctx *ctx = p;
	const char *s = d_path(&file->f_path, ctx->page, PAGE_SIZE);

	if (IS_ERR(s)) {
		struct dentry *dentry = file->f_path.dentry;

		/* Make sure we give at least some info */
		spin_lock(&dentry->d_lock);
		trace_lttng_statedump_file_descriptor(ctx->session, ctx->p, fd,
			dentry->d_name.name);
		spin_unlock(&dentry->d_lock);
		goto end;
	}
	trace_lttng_statedump_file_descriptor(ctx->session, ctx->p, fd, s);
end:
	return 0;
}

static
void lttng_enumerate_task_fd(struct lttng_session *session,
		struct task_struct *p, char *tmp)
{
	struct lttng_fd_ctx ctx = { .page = tmp, .session = session, .p = p };

	task_lock(p);
	lttng_iterate_fd(p->files, 0, lttng_dump_one_fd, &ctx);
	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;
}

#if 0
/*
 * FIXME: we cannot take a mmap_sem while in a RCU read-side critical section
 * (scheduling in atomic). Normally, the tasklist lock protects this kind of
 * iteration, but it is not exported to modules.
 */
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;
}
#endif

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

static
void lttng_statedump_process_ns(struct lttng_session *session,
		struct task_struct *p,
		enum lttng_thread_type type,
		enum lttng_execution_mode mode,
		enum lttng_execution_submode submode,
		enum lttng_process_status status)
{
	struct nsproxy *proxy;
	struct pid_namespace *pid_ns;

	rcu_read_lock();
	proxy = task_nsproxy(p);
	if (proxy) {
		pid_ns = proxy->pid_ns;
		do {
			trace_lttng_statedump_process_state(session,
				p, type, mode, submode, status, pid_ns);
			pid_ns = pid_ns->parent;
		} while (pid_ns);
	} else {
		trace_lttng_statedump_process_state(session,
			p, type, mode, submode, status, NULL);
	}
	rcu_read_unlock();
}

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;
			lttng_statedump_process_ns(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);
	/* FIXME 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"
3a523f5b	51	#include "wrapper/spinlock.h"
361c023a	52	#include "wrapper/fdtable.h"
c337ddc2 MD	53
	54	#ifdef CONFIG_GENERIC_HARDIRQS
	55	#include <linux/irq.h>
	56	#endif
	57
	58	/* Define the tracepoints, but do not build the probes */
	59	#define CREATE_TRACE_POINTS
	60	#define TRACE_INCLUDE_PATH ../instrumentation/events/lttng-module
	61	#define TRACE_INCLUDE_FILE lttng-statedump
	62	#include "instrumentation/events/lttng-module/lttng-statedump.h"
	63
361c023a MD	64	struct lttng_fd_ctx {
	65	char *page;
	66	struct lttng_session *session;
	67	struct task_struct *p;
	68	};
	69
c337ddc2 MD	70	/*
	71	* Protected by the trace lock.
	72	*/
	73	static struct delayed_work cpu_work[NR_CPUS];
	74	static DECLARE_WAIT_QUEUE_HEAD(statedump_wq);
	75	static atomic_t kernel_threads_to_run;
	76
	77	enum lttng_thread_type {
	78	LTTNG_USER_THREAD = 0,
	79	LTTNG_KERNEL_THREAD = 1,
	80	};
	81
	82	enum lttng_execution_mode {
	83	LTTNG_USER_MODE = 0,
	84	LTTNG_SYSCALL = 1,
	85	LTTNG_TRAP = 2,
	86	LTTNG_IRQ = 3,
	87	LTTNG_SOFTIRQ = 4,
	88	LTTNG_MODE_UNKNOWN = 5,
	89	};
	90
	91	enum lttng_execution_submode {
	92	LTTNG_NONE = 0,
	93	LTTNG_UNKNOWN = 1,
	94	};
	95
	96	enum lttng_process_status {
	97	LTTNG_UNNAMED = 0,
	98	LTTNG_WAIT_FORK = 1,
	99	LTTNG_WAIT_CPU = 2,
	100	LTTNG_EXIT = 3,
	101	LTTNG_ZOMBIE = 4,
	102	LTTNG_WAIT = 5,
	103	LTTNG_RUN = 6,
	104	LTTNG_DEAD = 7,
	105	};
	106
	107	#ifdef CONFIG_INET
	108	static
	109	void lttng_enumerate_device(struct lttng_session *session,
	110	struct net_device *dev)
	111	{
	112	struct in_device *in_dev;
	113	struct in_ifaddr *ifa;
	114
	115	if (dev->flags & IFF_UP) {
	116	in_dev = in_dev_get(dev);
	117	if (in_dev) {
	118	for (ifa = in_dev->ifa_list; ifa != NULL;
	119	ifa = ifa->ifa_next) {
	120	trace_lttng_statedump_network_interface(
	121	session, dev, ifa);
	122	}
	123	in_dev_put(in_dev);
	124	}
	125	} else {
	126	trace_lttng_statedump_network_interface(
	127	session, dev, NULL);
	128	}
	129	}
	130
	131	static
	132	int lttng_enumerate_network_ip_interface(struct lttng_session *session)
	133	{
134	struct net_device *dev;
135
136	read_lock(&dev_base_lock);
137	for_each_netdev(&init_net, dev)
138	lttng_enumerate_device(session, dev);
139	read_unlock(&dev_base_lock);
140
141	return 0;
142	}
143	#else /* CONFIG_INET */
144	static inline
145	int lttng_enumerate_network_ip_interface(struct lttng_session *session)
146	{
147	return 0;
148	}
149	#endif /* CONFIG_INET */
150
361c023a MD	151	static
	152	int lttng_dump_one_fd(const void p, struct file file, unsigned int fd)
	153	{
	154	const struct lttng_fd_ctx *ctx = p;
	155	const char *s = d_path(&file->f_path, ctx->page, PAGE_SIZE);
	156
	157	if (IS_ERR(s)) {
	158	struct dentry *dentry = file->f_path.dentry;
	159
	160	/* Make sure we give at least some info */
	161	spin_lock(&dentry->d_lock);
	162	trace_lttng_statedump_file_descriptor(ctx->session, ctx->p, fd,
	163	dentry->d_name.name);
	164	spin_unlock(&dentry->d_lock);
	165	goto end;
	166	}
	167	trace_lttng_statedump_file_descriptor(ctx->session, ctx->p, fd, s);
	168	end:
	169	return 0;
	170	}
c337ddc2 MD	171
	172	static
	173	void lttng_enumerate_task_fd(struct lttng_session *session,
	174	struct task_struct p, char tmp)
	175	{
361c023a	176	struct lttng_fd_ctx ctx = { .page = tmp, .session = session, .p = p };
c337ddc2 MD	177
c337ddc2 MD	178	task_lock(p);
361c023a	179	lttng_iterate_fd(p->files, 0, lttng_dump_one_fd, &ctx);
c337ddc2 MD	180	task_unlock(p);
	181	}
	182
	183	static
	184	int lttng_enumerate_file_descriptors(struct lttng_session *session)
	185	{
	186	struct task_struct *p;
	187	char tmp = (char ) __get_free_page(GFP_KERNEL);
	188
	189	/* Enumerate active file descriptors */
	190	rcu_read_lock();
	191	for_each_process(p)
	192	lttng_enumerate_task_fd(session, p, tmp);
	193	rcu_read_unlock();
	194	free_page((unsigned long) tmp);
	195	return 0;
	196	}
	197
0658bdda MD	198	#if 0
	199	/*
	200	* FIXME: we cannot take a mmap_sem while in a RCU read-side critical section
	201	* (scheduling in atomic). Normally, the tasklist lock protects this kind of
	202	* iteration, but it is not exported to modules.
	203	*/
c337ddc2 MD	204	static
	205	void lttng_enumerate_task_vm_maps(struct lttng_session *session,
	206	struct task_struct *p)
	207	{
	208	struct mm_struct *mm;
	209	struct vm_area_struct *map;
	210	unsigned long ino;
	211
	212	/* get_task_mm does a task_lock... */
	213	mm = get_task_mm(p);
	214	if (!mm)
	215	return;
	216
	217	map = mm->mmap;
	218	if (map) {
	219	down_read(&mm->mmap_sem);
	220	while (map) {
	221	if (map->vm_file)
	222	ino = map->vm_file->f_dentry->d_inode->i_ino;
	223	else
	224	ino = 0;
	225	trace_lttng_statedump_vm_map(session, p, map, ino);
	226	map = map->vm_next;
	227	}
	228	up_read(&mm->mmap_sem);
	229	}
	230	mmput(mm);
	231	}
	232
	233	static
	234	int lttng_enumerate_vm_maps(struct lttng_session *session)
	235	{
	236	struct task_struct *p;
	237
	238	rcu_read_lock();
	239	for_each_process(p)
	240	lttng_enumerate_task_vm_maps(session, p);
	241	rcu_read_unlock();
	242	return 0;
	243	}
0658bdda	244	#endif
c337ddc2 MD	245
c337ddc2 MD	246	#ifdef CONFIG_GENERIC_HARDIRQS
47faec4b JN	247
	248	#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,39))
	249	#define irq_desc_get_chip(desc) get_irq_desc_chip(desc)
	250	#endif
	251
c337ddc2 MD	252	static
	253	void lttng_list_interrupts(struct lttng_session *session)
	254	{
	255	unsigned int irq;
	256	unsigned long flags = 0;
	257	struct irq_desc *desc;
	258
	259	#define irq_to_desc wrapper_irq_to_desc
	260	/* needs irq_desc */
	261	for_each_irq_desc(irq, desc) {
	262	struct irqaction *action;
	263	const char *irq_chip_name =
	264	irq_desc_get_chip(desc)->name ? : "unnamed_irq_chip";
	265
	266	local_irq_save(flags);
3a523f5b	267	wrapper_desc_spin_lock(&desc->lock);
c337ddc2 MD	268	for (action = desc->action; action; action = action->next) {
	269	trace_lttng_statedump_interrupt(session,
	270	irq, irq_chip_name, action);
	271	}
3a523f5b	272	wrapper_desc_spin_unlock(&desc->lock);
c337ddc2 MD	273	local_irq_restore(flags);
	274	}
	275	#undef irq_to_desc
	276	}
	277	#else
	278	static inline
	279	void list_interrupts(struct lttng_session *session)
	280	{
	281	}
	282	#endif
	283
73e8ba37 JD	284	static
	285	void lttng_statedump_process_ns(struct lttng_session *session,
	286	struct task_struct *p,
	287	enum lttng_thread_type type,
	288	enum lttng_execution_mode mode,
	289	enum lttng_execution_submode submode,
	290	enum lttng_process_status status)
	291	{
	292	struct nsproxy *proxy;
	293	struct pid_namespace *pid_ns;
	294
	295	rcu_read_lock();
	296	proxy = task_nsproxy(p);
	297	if (proxy) {
	298	pid_ns = proxy->pid_ns;
	299	do {
	300	trace_lttng_statedump_process_state(session,
	301	p, type, mode, submode, status, pid_ns);
af73f727	302	pid_ns = pid_ns->parent;
73e8ba37 JD	303	} while (pid_ns);
	304	} else {
	305	trace_lttng_statedump_process_state(session,
	306	p, type, mode, submode, status, NULL);
	307	}
	308	rcu_read_unlock();
	309	}
	310
c337ddc2 MD	311	static
	312	int lttng_enumerate_process_states(struct lttng_session *session)
	313	{
	314	struct task_struct g, p;
	315
	316	rcu_read_lock();
	317	for_each_process(g) {
	318	p = g;
	319	do {
	320	enum lttng_execution_mode mode =
	321	LTTNG_MODE_UNKNOWN;
	322	enum lttng_execution_submode submode =
	323	LTTNG_UNKNOWN;
	324	enum lttng_process_status status;
	325	enum lttng_thread_type type;
	326
	327	task_lock(p);
	328	if (p->exit_state == EXIT_ZOMBIE)
	329	status = LTTNG_ZOMBIE;
	330	else if (p->exit_state == EXIT_DEAD)
	331	status = LTTNG_DEAD;
	332	else if (p->state == TASK_RUNNING) {
	333	/* Is this a forked child that has not run yet? */
	334	if (list_empty(&p->rt.run_list))
	335	status = LTTNG_WAIT_FORK;
	336	else
	337	/*
	338	* All tasks are considered as wait_cpu;
	339	* the viewer will sort out if the task
	340	* was really running at this time.
	341	*/
	342	status = LTTNG_WAIT_CPU;
	343	} else if (p->state &
	344	(TASK_INTERRUPTIBLE \| TASK_UNINTERRUPTIBLE)) {
	345	/* Task is waiting for something to complete */
	346	status = LTTNG_WAIT;
	347	} else
	348	status = LTTNG_UNNAMED;
	349	submode = LTTNG_NONE;
	350
	351	/*
	352	* Verification of t->mm is to filter out kernel
	353	* threads; Viewer will further filter out if a
	354	* user-space thread was in syscall mode or not.
	355	*/
	356	if (p->mm)
	357	type = LTTNG_USER_THREAD;
	358	else
	359	type = LTTNG_KERNEL_THREAD;
73e8ba37	360	lttng_statedump_process_ns(session,
c337ddc2 MD	361	p, type, mode, submode, status);
	362	task_unlock(p);
	363	} while_each_thread(g, p);
	364	}
	365	rcu_read_unlock();
	366
	367	return 0;
	368	}
	369
	370	static
	371	void lttng_statedump_work_func(struct work_struct *work)
	372	{
	373	if (atomic_dec_and_test(&kernel_threads_to_run))
	374	/* If we are the last thread, wake up do_lttng_statedump */
	375	wake_up(&statedump_wq);
	376	}
	377
	378	static
	379	int do_lttng_statedump(struct lttng_session *session)
	380	{
	381	int cpu;
	382
	383	printk(KERN_DEBUG "LTT state dump thread start\n");
	384	trace_lttng_statedump_start(session);
	385	lttng_enumerate_process_states(session);
	386	lttng_enumerate_file_descriptors(session);
0658bdda	387	/* FIXME lttng_enumerate_vm_maps(session); */
c337ddc2 MD	388	lttng_list_interrupts(session);
	389	lttng_enumerate_network_ip_interface(session);
	390
	391	/* TODO lttng_dump_idt_table(session); */
	392	/* TODO lttng_dump_softirq_vec(session); */
	393	/* TODO lttng_list_modules(session); */
	394	/* TODO lttng_dump_swap_files(session); */
	395
	396	/*
	397	* Fire off a work queue on each CPU. Their sole purpose in life
	398	* is to guarantee that each CPU has been in a state where is was in
	399	* syscall mode (i.e. not in a trap, an IRQ or a soft IRQ).
	400	*/
	401	get_online_cpus();
	402	atomic_set(&kernel_threads_to_run, num_online_cpus());
	403	for_each_online_cpu(cpu) {
	404	INIT_DELAYED_WORK(&cpu_work[cpu], lttng_statedump_work_func);
	405	schedule_delayed_work_on(cpu, &cpu_work[cpu], 0);
	406	}
	407	/* Wait for all threads to run */
7a7128e0	408	__wait_event(statedump_wq, (atomic_read(&kernel_threads_to_run) == 0));
c337ddc2 MD	409	put_online_cpus();
	410	/* Our work is done */
	411	printk(KERN_DEBUG "LTT state dump end\n");
	412	trace_lttng_statedump_end(session);
	413	return 0;
	414	}
	415
	416	/*
	417	* Called with session mutex held.
	418	*/
	419	int lttng_statedump_start(struct lttng_session *session)
	420	{
	421	printk(KERN_DEBUG "LTTng: state dump begin\n");
	422	return do_lttng_statedump(session);
	423	}
	424	EXPORT_SYMBOL_GPL(lttng_statedump_start);
	425
	426	MODULE_LICENSE("GPL and additional rights");
	427	MODULE_AUTHOR("Jean-Hugues Deschenes");
	428	MODULE_DESCRIPTION("Linux Trace Toolkit Next Generation Statedump");