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

/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
 *
 * 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>
 *
 * 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 <linux/device.h>

#include <lttng-events.h>
#include <lttng-tracer.h>
#include <wrapper/irqdesc.h>
#include <wrapper/spinlock.h>
#include <wrapper/fdtable.h>
#include <wrapper/irq.h>
#include <wrapper/tracepoint.h>
#include <wrapper/genhd.h>
#include <wrapper/file.h>
#include <wrapper/time.h>

#ifdef CONFIG_LTTNG_HAS_LIST_IRQ
#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
#define LTTNG_INSTRUMENTATION
#include <instrumentation/events/lttng-module/lttng-statedump.h>

DEFINE_TRACE(lttng_statedump_block_device);
DEFINE_TRACE(lttng_statedump_end);
DEFINE_TRACE(lttng_statedump_interrupt);
DEFINE_TRACE(lttng_statedump_file_descriptor);
DEFINE_TRACE(lttng_statedump_start);
DEFINE_TRACE(lttng_statedump_process_state);
DEFINE_TRACE(lttng_statedump_network_interface);

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

/*
 * 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,
};

static
int lttng_enumerate_block_devices(struct lttng_session *session)
{
	struct class *ptr_block_class;
	struct device_type *ptr_disk_type;
	struct class_dev_iter iter;
	struct device *dev;

	ptr_block_class = wrapper_get_block_class();
	if (!ptr_block_class)
		return -ENOSYS;
	ptr_disk_type = wrapper_get_disk_type();
	if (!ptr_disk_type) {
		return -ENOSYS;
	}
	class_dev_iter_init(&iter, ptr_block_class, NULL, ptr_disk_type);
	while ((dev = class_dev_iter_next(&iter))) {
		struct disk_part_iter piter;
		struct gendisk *disk = dev_to_disk(dev);
		struct hd_struct *part;

		/*
		 * Don't show empty devices or things that have been
		 * suppressed
		 */
		if (get_capacity(disk) == 0 ||
		    (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
			continue;

		disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
		while ((part = disk_part_iter_next(&piter))) {
			char name_buf[BDEVNAME_SIZE];
			char *p;

			p = wrapper_disk_name(disk, part->partno, name_buf);
			if (!p) {
				disk_part_iter_exit(&piter);
				class_dev_iter_exit(&iter);
				return -ENOSYS;
			}
			trace_lttng_statedump_block_device(session,
					part_devt(part), name_buf);
		}
		disk_part_iter_exit(&piter);
	}
	class_dev_iter_exit(&iter);
	return 0;
}

#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);
	unsigned int flags = file->f_flags;
	struct fdtable *fdt;

	/*
	 * We don't expose kernel internal flags, only userspace-visible
	 * flags.
	 */
	flags &= ~FMODE_NONOTIFY;
	fdt = files_fdtable(ctx->files);
	/*
	 * We need to check here again whether fd is within the fdt
	 * max_fds range, because we might be seeing a different
	 * files_fdtable() than iterate_fd(), assuming only RCU is
	 * protecting the read. In reality, iterate_fd() holds
	 * file_lock, which should ensure the fdt does not change while
	 * the lock is taken, but we are not aware whether this is
	 * guaranteed or not, so play safe.
	 */
	if (fd < fdt->max_fds && lttng_close_on_exec(fd, fdt))
		flags |= O_CLOEXEC;
	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, flags, file->f_mode);
		spin_unlock(&dentry->d_lock);
		goto end;
	}
	trace_lttng_statedump_file_descriptor(ctx->session, ctx->p, fd, s,
		flags, file->f_mode);
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 };
	struct files_struct *files;

	task_lock(p);
	files = p->files;
	if (!files)
		goto end;
	ctx.files = files;
	lttng_iterate_fd(files, 0, lttng_dump_one_fd, &ctx);
end:
	task_unlock(p);
}

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

	tmp = (char *) __get_free_page(GFP_KERNEL);
	if (!tmp)
		return -ENOMEM;

	/* 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->lttng_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_LTTNG_HAS_LIST_IRQ

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

static
int 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);
	}
	return 0;
#undef irq_to_desc
}
#else
static inline
int lttng_list_interrupts(struct lttng_session *session)
{
	return 0;
}
#endif

/*
 * Called with task lock held.
 */
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 pid_namespace *pid_ns;

	pid_ns = task_active_pid_ns(p);
	do {
		trace_lttng_statedump_process_state(session,
			p, type, mode, submode, status, pid_ns);
		pid_ns = pid_ns ? pid_ns->parent : NULL;
	} while (pid_ns);
}

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, ret;

	trace_lttng_statedump_start(session);
	ret = lttng_enumerate_process_states(session);
	if (ret)
		return ret;
	ret = lttng_enumerate_file_descriptors(session);
	if (ret)
		return ret;
	/*
	 * FIXME
	 * ret = lttng_enumerate_vm_maps(session);
	 * if (ret)
	 * 	return ret;
	 */
	ret = lttng_list_interrupts(session);
	if (ret)
		return ret;
	ret = lttng_enumerate_network_ip_interface(session);
	if (ret)
		return ret;
	ret = lttng_enumerate_block_devices(session);
	switch (ret) {
	case 0:
		break;
	case -ENOSYS:
		printk(KERN_WARNING "LTTng: block device enumeration is not supported by kernel\n");
		break;
	default:
		return ret;
	}

	/* 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 */
	trace_lttng_statedump_end(session);
	return 0;
}

/*
 * Called with session mutex held.
 */
int lttng_statedump_start(struct lttng_session *session)
{
	return do_lttng_statedump(session);
}
EXPORT_SYMBOL_GPL(lttng_statedump_start);

static
int __init lttng_statedump_init(void)
{
	/*
	 * Allow module to load even if the fixup cannot be done. This
	 * will allow seemless transition when the underlying issue fix
	 * is merged into the Linux kernel, and when tracepoint.c
	 * "tracepoint_module_notify" is turned into a static function.
	 */
	(void) wrapper_lttng_fixup_sig(THIS_MODULE);
	return 0;
}

module_init(lttng_statedump_init);

static
void __exit lttng_statedump_exit(void)
{
}

module_exit(lttng_statedump_exit);

MODULE_LICENSE("GPL and additional rights");
MODULE_AUTHOR("Jean-Hugues Deschenes");
MODULE_DESCRIPTION("LTTng statedump provider");
MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
	__stringify(LTTNG_MODULES_MINOR_VERSION) "."
	__stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
	LTTNG_MODULES_EXTRAVERSION);
Commit	Line	Data
9f36eaed MJ	1	/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
9f36eaed MJ	2	*
886d51a3 MD	3	* lttng-statedump.c
886d51a3 MD	4	*
c337ddc2 MD	5	* Linux Trace Toolkit Next Generation Kernel State Dump
	6	*
	7	* Copyright 2005 Jean-Hugues Deschenes <jean-hugues.deschenes@polymtl.ca>
	8	* Copyright 2006-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	9	*
	10	* Changes:
	11	* Eric Clement: Add listing of network IP interface
	12	* 2006, 2007 Mathieu Desnoyers Fix kernel threads
	13	* Various updates
c337ddc2 MD	14	*/
	15
	16	#include <linux/init.h>
	17	#include <linux/module.h>
	18	#include <linux/netlink.h>
	19	#include <linux/inet.h>
	20	#include <linux/ip.h>
	21	#include <linux/kthread.h>
	22	#include <linux/proc_fs.h>
	23	#include <linux/file.h>
	24	#include <linux/interrupt.h>
	25	#include <linux/irqnr.h>
	26	#include <linux/cpu.h>
	27	#include <linux/netdevice.h>
	28	#include <linux/inetdevice.h>
	29	#include <linux/sched.h>
	30	#include <linux/mm.h>
	31	#include <linux/fdtable.h>
	32	#include <linux/swap.h>
	33	#include <linux/wait.h>
	34	#include <linux/mutex.h>
f0dbdefb	35	#include <linux/device.h>
c337ddc2	36
241ae9a8 MD	37	#include <lttng-events.h>
	38	#include <lttng-tracer.h>
	39	#include <wrapper/irqdesc.h>
	40	#include <wrapper/spinlock.h>
	41	#include <wrapper/fdtable.h>
241ae9a8 MD	42	#include <wrapper/irq.h>
	43	#include <wrapper/tracepoint.h>
	44	#include <wrapper/genhd.h>
	45	#include <wrapper/file.h>
	46	#include <wrapper/time.h>
c337ddc2	47
29784493	48	#ifdef CONFIG_LTTNG_HAS_LIST_IRQ
c337ddc2 MD	49	#include <linux/irq.h>
	50	#endif
	51
	52	/* Define the tracepoints, but do not build the probes */
	53	#define CREATE_TRACE_POINTS
241ae9a8	54	#define TRACE_INCLUDE_PATH instrumentation/events/lttng-module
c337ddc2	55	#define TRACE_INCLUDE_FILE lttng-statedump
3bc29f0a	56	#define LTTNG_INSTRUMENTATION
241ae9a8	57	#include <instrumentation/events/lttng-module/lttng-statedump.h>
c337ddc2	58
f0dbdefb	59	DEFINE_TRACE(lttng_statedump_block_device);
20591cf7 MD	60	DEFINE_TRACE(lttng_statedump_end);
	61	DEFINE_TRACE(lttng_statedump_interrupt);
	62	DEFINE_TRACE(lttng_statedump_file_descriptor);
	63	DEFINE_TRACE(lttng_statedump_start);
	64	DEFINE_TRACE(lttng_statedump_process_state);
	65	DEFINE_TRACE(lttng_statedump_network_interface);
	66
361c023a MD	67	struct lttng_fd_ctx {
	68	char *page;
	69	struct lttng_session *session;
	70	struct task_struct *p;
d561ecfb	71	struct files_struct *files;
361c023a MD	72	};
361c023a MD	73
c337ddc2 MD	74	/*
	75	* Protected by the trace lock.
	76	*/
	77	static struct delayed_work cpu_work[NR_CPUS];
	78	static DECLARE_WAIT_QUEUE_HEAD(statedump_wq);
	79	static atomic_t kernel_threads_to_run;
	80
	81	enum lttng_thread_type {
	82	LTTNG_USER_THREAD = 0,
	83	LTTNG_KERNEL_THREAD = 1,
	84	};
	85
	86	enum lttng_execution_mode {
	87	LTTNG_USER_MODE = 0,
	88	LTTNG_SYSCALL = 1,
	89	LTTNG_TRAP = 2,
	90	LTTNG_IRQ = 3,
	91	LTTNG_SOFTIRQ = 4,
	92	LTTNG_MODE_UNKNOWN = 5,
	93	};
	94
	95	enum lttng_execution_submode {
	96	LTTNG_NONE = 0,
	97	LTTNG_UNKNOWN = 1,
	98	};
	99
	100	enum lttng_process_status {
	101	LTTNG_UNNAMED = 0,
	102	LTTNG_WAIT_FORK = 1,
	103	LTTNG_WAIT_CPU = 2,
	104	LTTNG_EXIT = 3,
	105	LTTNG_ZOMBIE = 4,
	106	LTTNG_WAIT = 5,
	107	LTTNG_RUN = 6,
	108	LTTNG_DEAD = 7,
	109	};
	110
f0dbdefb HD	111	static
	112	int lttng_enumerate_block_devices(struct lttng_session *session)
	113	{
	114	struct class *ptr_block_class;
	115	struct device_type *ptr_disk_type;
	116	struct class_dev_iter iter;
	117	struct device *dev;
	118
	119	ptr_block_class = wrapper_get_block_class();
	120	if (!ptr_block_class)
	121	return -ENOSYS;
	122	ptr_disk_type = wrapper_get_disk_type();
	123	if (!ptr_disk_type) {
	124	return -ENOSYS;
	125	}
	126	class_dev_iter_init(&iter, ptr_block_class, NULL, ptr_disk_type);
	127	while ((dev = class_dev_iter_next(&iter))) {
	128	struct disk_part_iter piter;
	129	struct gendisk *disk = dev_to_disk(dev);
	130	struct hd_struct *part;
	131
5a91f3df MD	132	/*
	133	* Don't show empty devices or things that have been
	134	* suppressed
	135	*/
	136	if (get_capacity(disk) == 0 \|\|
	137	(disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
	138	continue;
	139
f0dbdefb HD	140	disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
	141	while ((part = disk_part_iter_next(&piter))) {
	142	char name_buf[BDEVNAME_SIZE];
	143	char *p;
	144
	145	p = wrapper_disk_name(disk, part->partno, name_buf);
	146	if (!p) {
	147	disk_part_iter_exit(&piter);
	148	class_dev_iter_exit(&iter);
	149	return -ENOSYS;
	150	}
	151	trace_lttng_statedump_block_device(session,
	152	part_devt(part), name_buf);
	153	}
	154	disk_part_iter_exit(&piter);
	155	}
	156	class_dev_iter_exit(&iter);
	157	return 0;
	158	}
	159
c337ddc2	160	#ifdef CONFIG_INET
f0dbdefb	161
c337ddc2 MD	162	static
	163	void lttng_enumerate_device(struct lttng_session *session,
	164	struct net_device *dev)
	165	{
	166	struct in_device *in_dev;
	167	struct in_ifaddr *ifa;
	168
	169	if (dev->flags & IFF_UP) {
	170	in_dev = in_dev_get(dev);
	171	if (in_dev) {
	172	for (ifa = in_dev->ifa_list; ifa != NULL;
	173	ifa = ifa->ifa_next) {
	174	trace_lttng_statedump_network_interface(
	175	session, dev, ifa);
	176	}
	177	in_dev_put(in_dev);
	178	}
	179	} else {
	180	trace_lttng_statedump_network_interface(
	181	session, dev, NULL);
	182	}
	183	}
	184
	185	static
	186	int lttng_enumerate_network_ip_interface(struct lttng_session *session)
	187	{
	188	struct net_device *dev;
	189
	190	read_lock(&dev_base_lock);
	191	for_each_netdev(&init_net, dev)
	192	lttng_enumerate_device(session, dev);
	193	read_unlock(&dev_base_lock);
	194
	195	return 0;
	196	}
	197	#else /* CONFIG_INET */
	198	static inline
	199	int lttng_enumerate_network_ip_interface(struct lttng_session *session)
	200	{
	201	return 0;
	202	}
	203	#endif /* CONFIG_INET */
	204
361c023a MD	205	static
	206	int lttng_dump_one_fd(const void p, struct file file, unsigned int fd)
	207	{
	208	const struct lttng_fd_ctx *ctx = p;
	209	const char *s = d_path(&file->f_path, ctx->page, PAGE_SIZE);
29021503	210	unsigned int flags = file->f_flags;
d561ecfb	211	struct fdtable *fdt;
361c023a	212
29021503 MD	213	/*
	214	* We don't expose kernel internal flags, only userspace-visible
	215	* flags.
	216	*/
	217	flags &= ~FMODE_NONOTIFY;
d561ecfb MD	218	fdt = files_fdtable(ctx->files);
	219	/*
	220	* We need to check here again whether fd is within the fdt
	221	* max_fds range, because we might be seeing a different
	222	* files_fdtable() than iterate_fd(), assuming only RCU is
	223	* protecting the read. In reality, iterate_fd() holds
	224	* file_lock, which should ensure the fdt does not change while
	225	* the lock is taken, but we are not aware whether this is
	226	* guaranteed or not, so play safe.
	227	*/
aa29f2d3	228	if (fd < fdt->max_fds && lttng_close_on_exec(fd, fdt))
29021503	229	flags \|= O_CLOEXEC;
361c023a MD	230	if (IS_ERR(s)) {
	231	struct dentry *dentry = file->f_path.dentry;
	232
	233	/* Make sure we give at least some info */
	234	spin_lock(&dentry->d_lock);
	235	trace_lttng_statedump_file_descriptor(ctx->session, ctx->p, fd,
29021503	236	dentry->d_name.name, flags, file->f_mode);
361c023a MD	237	spin_unlock(&dentry->d_lock);
	238	goto end;
	239	}
29021503 MD	240	trace_lttng_statedump_file_descriptor(ctx->session, ctx->p, fd, s,
29021503 MD	241	flags, file->f_mode);
361c023a MD	242	end:
	243	return 0;
	244	}
c337ddc2 MD	245
	246	static
	247	void lttng_enumerate_task_fd(struct lttng_session *session,
	248	struct task_struct p, char tmp)
	249	{
361c023a	250	struct lttng_fd_ctx ctx = { .page = tmp, .session = session, .p = p };
d561ecfb	251	struct files_struct *files;
c337ddc2 MD	252
c337ddc2 MD	253	task_lock(p);
d561ecfb MD	254	files = p->files;
	255	if (!files)
	256	goto end;
	257	ctx.files = files;
	258	lttng_iterate_fd(files, 0, lttng_dump_one_fd, &ctx);
	259	end:
c337ddc2 MD	260	task_unlock(p);
	261	}
	262
	263	static
	264	int lttng_enumerate_file_descriptors(struct lttng_session *session)
	265	{
	266	struct task_struct *p;
cfcee1c7 MD	267	char *tmp;
	268
	269	tmp = (char *) __get_free_page(GFP_KERNEL);
	270	if (!tmp)
	271	return -ENOMEM;
c337ddc2 MD	272
	273	/* Enumerate active file descriptors */
	274	rcu_read_lock();
	275	for_each_process(p)
	276	lttng_enumerate_task_fd(session, p, tmp);
	277	rcu_read_unlock();
	278	free_page((unsigned long) tmp);
	279	return 0;
	280	}
	281
0658bdda MD	282	#if 0
	283	/*
	284	* FIXME: we cannot take a mmap_sem while in a RCU read-side critical section
	285	* (scheduling in atomic). Normally, the tasklist lock protects this kind of
	286	* iteration, but it is not exported to modules.
	287	*/
c337ddc2 MD	288	static
	289	void lttng_enumerate_task_vm_maps(struct lttng_session *session,
	290	struct task_struct *p)
	291	{
	292	struct mm_struct *mm;
	293	struct vm_area_struct *map;
	294	unsigned long ino;
	295
	296	/* get_task_mm does a task_lock... */
	297	mm = get_task_mm(p);
	298	if (!mm)
	299	return;
	300
	301	map = mm->mmap;
	302	if (map) {
	303	down_read(&mm->mmap_sem);
	304	while (map) {
	305	if (map->vm_file)
b06ed645	306	ino = map->vm_file->lttng_f_dentry->d_inode->i_ino;
c337ddc2 MD	307	else
	308	ino = 0;
	309	trace_lttng_statedump_vm_map(session, p, map, ino);
	310	map = map->vm_next;
	311	}
	312	up_read(&mm->mmap_sem);
	313	}
	314	mmput(mm);
	315	}
	316
	317	static
	318	int lttng_enumerate_vm_maps(struct lttng_session *session)
	319	{
	320	struct task_struct *p;
	321
	322	rcu_read_lock();
	323	for_each_process(p)
	324	lttng_enumerate_task_vm_maps(session, p);
	325	rcu_read_unlock();
	326	return 0;
	327	}
0658bdda	328	#endif
c337ddc2	329
29784493	330	#ifdef CONFIG_LTTNG_HAS_LIST_IRQ
47faec4b JN	331
	332	#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,39))
	333	#define irq_desc_get_chip(desc) get_irq_desc_chip(desc)
	334	#endif
	335
c337ddc2	336	static
cfcee1c7	337	int lttng_list_interrupts(struct lttng_session *session)
c337ddc2 MD	338	{
	339	unsigned int irq;
	340	unsigned long flags = 0;
	341	struct irq_desc *desc;
	342
	343	#define irq_to_desc wrapper_irq_to_desc
	344	/* needs irq_desc */
	345	for_each_irq_desc(irq, desc) {
	346	struct irqaction *action;
	347	const char *irq_chip_name =
	348	irq_desc_get_chip(desc)->name ? : "unnamed_irq_chip";
	349
	350	local_irq_save(flags);
3a523f5b	351	wrapper_desc_spin_lock(&desc->lock);
c337ddc2 MD	352	for (action = desc->action; action; action = action->next) {
	353	trace_lttng_statedump_interrupt(session,
	354	irq, irq_chip_name, action);
	355	}
3a523f5b	356	wrapper_desc_spin_unlock(&desc->lock);
c337ddc2 MD	357	local_irq_restore(flags);
c337ddc2 MD	358	}
cfcee1c7	359	return 0;
c337ddc2 MD	360	#undef irq_to_desc
	361	}
	362	#else
	363	static inline
cfcee1c7	364	int lttng_list_interrupts(struct lttng_session *session)
c337ddc2	365	{
cfcee1c7	366	return 0;
c337ddc2 MD	367	}
	368	#endif
	369
4ba1f53c MD	370	/*
	371	* Called with task lock held.
	372	*/
73e8ba37 JD	373	static
	374	void lttng_statedump_process_ns(struct lttng_session *session,
	375	struct task_struct *p,
	376	enum lttng_thread_type type,
	377	enum lttng_execution_mode mode,
	378	enum lttng_execution_submode submode,
	379	enum lttng_process_status status)
	380	{
73e8ba37 JD	381	struct pid_namespace *pid_ns;
73e8ba37 JD	382
887bcdac MJ	383	pid_ns = task_active_pid_ns(p);
887bcdac MJ	384	do {
73e8ba37	385	trace_lttng_statedump_process_state(session,
887bcdac	386	p, type, mode, submode, status, pid_ns);
d16203a5	387	pid_ns = pid_ns ? pid_ns->parent : NULL;
887bcdac	388	} while (pid_ns);
73e8ba37 JD	389	}
73e8ba37 JD	390
c337ddc2 MD	391	static
	392	int lttng_enumerate_process_states(struct lttng_session *session)
	393	{
	394	struct task_struct g, p;
	395
	396	rcu_read_lock();
	397	for_each_process(g) {
	398	p = g;
	399	do {
	400	enum lttng_execution_mode mode =
	401	LTTNG_MODE_UNKNOWN;
	402	enum lttng_execution_submode submode =
	403	LTTNG_UNKNOWN;
	404	enum lttng_process_status status;
	405	enum lttng_thread_type type;
	406
	407	task_lock(p);
	408	if (p->exit_state == EXIT_ZOMBIE)
	409	status = LTTNG_ZOMBIE;
	410	else if (p->exit_state == EXIT_DEAD)
	411	status = LTTNG_DEAD;
	412	else if (p->state == TASK_RUNNING) {
	413	/* Is this a forked child that has not run yet? */
	414	if (list_empty(&p->rt.run_list))
	415	status = LTTNG_WAIT_FORK;
	416	else
	417	/*
	418	* All tasks are considered as wait_cpu;
	419	* the viewer will sort out if the task
	420	* was really running at this time.
	421	*/
	422	status = LTTNG_WAIT_CPU;
	423	} else if (p->state &
	424	(TASK_INTERRUPTIBLE \| TASK_UNINTERRUPTIBLE)) {
	425	/* Task is waiting for something to complete */
	426	status = LTTNG_WAIT;
	427	} else
	428	status = LTTNG_UNNAMED;
	429	submode = LTTNG_NONE;
	430
	431	/*
	432	* Verification of t->mm is to filter out kernel
	433	* threads; Viewer will further filter out if a
	434	* user-space thread was in syscall mode or not.
	435	*/
	436	if (p->mm)
	437	type = LTTNG_USER_THREAD;
	438	else
	439	type = LTTNG_KERNEL_THREAD;
73e8ba37	440	lttng_statedump_process_ns(session,
c337ddc2 MD	441	p, type, mode, submode, status);
	442	task_unlock(p);
	443	} while_each_thread(g, p);
	444	}
	445	rcu_read_unlock();
	446
	447	return 0;
	448	}
	449
	450	static
	451	void lttng_statedump_work_func(struct work_struct *work)
	452	{
	453	if (atomic_dec_and_test(&kernel_threads_to_run))
	454	/* If we are the last thread, wake up do_lttng_statedump */
	455	wake_up(&statedump_wq);
	456	}
	457
	458	static
	459	int do_lttng_statedump(struct lttng_session *session)
	460	{
cfcee1c7	461	int cpu, ret;
c337ddc2	462
c337ddc2	463	trace_lttng_statedump_start(session);
cfcee1c7 MD	464	ret = lttng_enumerate_process_states(session);
	465	if (ret)
	466	return ret;
	467	ret = lttng_enumerate_file_descriptors(session);
	468	if (ret)
	469	return ret;
	470	/*
	471	* FIXME
	472	* ret = lttng_enumerate_vm_maps(session);
	473	* if (ret)
	474	* return ret;
	475	*/
	476	ret = lttng_list_interrupts(session);
	477	if (ret)
	478	return ret;
	479	ret = lttng_enumerate_network_ip_interface(session);
	480	if (ret)
	481	return ret;
	482	ret = lttng_enumerate_block_devices(session);
	483	switch (ret) {
84c7055e MD	484	case 0:
84c7055e MD	485	break;
cfcee1c7 MD	486	case -ENOSYS:
	487	printk(KERN_WARNING "LTTng: block device enumeration is not supported by kernel\n");
	488	break;
	489	default:
	490	return ret;
	491	}
c337ddc2 MD	492
	493	/* TODO lttng_dump_idt_table(session); */
	494	/* TODO lttng_dump_softirq_vec(session); */
	495	/* TODO lttng_list_modules(session); */
	496	/* TODO lttng_dump_swap_files(session); */
	497
	498	/*
	499	* Fire off a work queue on each CPU. Their sole purpose in life
	500	* is to guarantee that each CPU has been in a state where is was in
	501	* syscall mode (i.e. not in a trap, an IRQ or a soft IRQ).
	502	*/
	503	get_online_cpus();
	504	atomic_set(&kernel_threads_to_run, num_online_cpus());
	505	for_each_online_cpu(cpu) {
	506	INIT_DELAYED_WORK(&cpu_work[cpu], lttng_statedump_work_func);
	507	schedule_delayed_work_on(cpu, &cpu_work[cpu], 0);
	508	}
	509	/* Wait for all threads to run */
7a7128e0	510	__wait_event(statedump_wq, (atomic_read(&kernel_threads_to_run) == 0));
c337ddc2 MD	511	put_online_cpus();
c337ddc2 MD	512	/* Our work is done */
c337ddc2 MD	513	trace_lttng_statedump_end(session);
	514	return 0;
	515	}
	516
	517	/*
	518	* Called with session mutex held.
	519	*/
	520	int lttng_statedump_start(struct lttng_session *session)
	521	{
c337ddc2 MD	522	return do_lttng_statedump(session);
	523	}
	524	EXPORT_SYMBOL_GPL(lttng_statedump_start);
	525
dd8d5afb MD	526	static
	527	int __init lttng_statedump_init(void)
	528	{
d16aa9c9 MD	529	/*
	530	* Allow module to load even if the fixup cannot be done. This
	531	* will allow seemless transition when the underlying issue fix
	532	* is merged into the Linux kernel, and when tracepoint.c
	533	* "tracepoint_module_notify" is turned into a static function.
	534	*/
	535	(void) wrapper_lttng_fixup_sig(THIS_MODULE);
	536	return 0;
dd8d5afb MD	537	}
	538
	539	module_init(lttng_statedump_init);
	540
461277e7 MD	541	static
	542	void __exit lttng_statedump_exit(void)
	543	{
	544	}
	545
	546	module_exit(lttng_statedump_exit);
	547
c337ddc2 MD	548	MODULE_LICENSE("GPL and additional rights");
c337ddc2 MD	549	MODULE_AUTHOR("Jean-Hugues Deschenes");
1c124020	550	MODULE_DESCRIPTION("LTTng statedump provider");
13ab8b0a MD	551	MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
	552	__stringify(LTTNG_MODULES_MINOR_VERSION) "."
	553	__stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
	554	LTTNG_MODULES_EXTRAVERSION);