[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/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/fdtable.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>

LTTNG_DEFINE_TRACE(lttng_statedump_block_device,
	TP_PROTO(struct lttng_session *session,
		dev_t dev, const char *diskname),
	TP_ARGS(session, dev, diskname));

LTTNG_DEFINE_TRACE(lttng_statedump_end,
	TP_PROTO(struct lttng_session *session),
	TP_ARGS(session));

LTTNG_DEFINE_TRACE(lttng_statedump_interrupt,
	TP_PROTO(struct lttng_session *session,
		unsigned int irq, const char *chip_name,
		struct irqaction *action),
	TP_ARGS(session, irq, chip_name, action));

LTTNG_DEFINE_TRACE(lttng_statedump_file_descriptor,
	TP_PROTO(struct lttng_session *session,
		struct files_struct *files,
		int fd, const char *filename,
		unsigned int flags, fmode_t fmode),
	TP_ARGS(session, files, fd, filename, flags, fmode));

LTTNG_DEFINE_TRACE(lttng_statedump_start,
	TP_PROTO(struct lttng_session *session),
	TP_ARGS(session));

LTTNG_DEFINE_TRACE(lttng_statedump_process_state,
	TP_PROTO(struct lttng_session *session,
		struct task_struct *p,
		int type, int mode, int submode, int status,
		struct files_struct *files),
	TP_ARGS(session, p, type, mode, submode, status, files));

LTTNG_DEFINE_TRACE(lttng_statedump_network_interface,
	TP_PROTO(struct lttng_session *session,
		struct net_device *dev, struct in_ifaddr *ifa),
	TP_ARGS(session, dev, ifa));

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))) {
			struct block_device bdev;
			char name_buf[BDEVNAME_SIZE];
			const char *p;

			/*
			 * Create a partial 'struct blockdevice' to use
			 * 'bdevname()' which is a simple wrapper over
			 * 'disk_name()' but has the honor to be EXPORT_SYMBOL.
			 */
			bdev.bd_disk = disk;
			bdev.bd_part = part;

			p = bdevname(&bdev, 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>
c337ddc2 MD	31	#include <linux/swap.h>
	32	#include <linux/wait.h>
	33	#include <linux/mutex.h>
f0dbdefb	34	#include <linux/device.h>
c337ddc2	35
241ae9a8 MD	36	#include <lttng-events.h>
	37	#include <lttng-tracer.h>
	38	#include <wrapper/irqdesc.h>
	39	#include <wrapper/spinlock.h>
	40	#include <wrapper/fdtable.h>
241ae9a8 MD	41	#include <wrapper/irq.h>
	42	#include <wrapper/tracepoint.h>
	43	#include <wrapper/genhd.h>
	44	#include <wrapper/file.h>
a117385f	45	#include <wrapper/fdtable.h>
c337ddc2	46
29784493	47	#ifdef CONFIG_LTTNG_HAS_LIST_IRQ
c337ddc2 MD	48	#include <linux/irq.h>
	49	#endif
	50
	51	/* Define the tracepoints, but do not build the probes */
	52	#define CREATE_TRACE_POINTS
241ae9a8	53	#define TRACE_INCLUDE_PATH instrumentation/events/lttng-module
c337ddc2	54	#define TRACE_INCLUDE_FILE lttng-statedump
3bc29f0a	55	#define LTTNG_INSTRUMENTATION
241ae9a8	56	#include <instrumentation/events/lttng-module/lttng-statedump.h>
c337ddc2	57
c6b31b34 MJ	58	LTTNG_DEFINE_TRACE(lttng_statedump_block_device,
	59	TP_PROTO(struct lttng_session *session,
	60	dev_t dev, const char *diskname),
	61	TP_ARGS(session, dev, diskname));
	62
	63	LTTNG_DEFINE_TRACE(lttng_statedump_end,
	64	TP_PROTO(struct lttng_session *session),
	65	TP_ARGS(session));
	66
	67	LTTNG_DEFINE_TRACE(lttng_statedump_interrupt,
	68	TP_PROTO(struct lttng_session *session,
	69	unsigned int irq, const char *chip_name,
	70	struct irqaction *action),
	71	TP_ARGS(session, irq, chip_name, action));
	72
	73	LTTNG_DEFINE_TRACE(lttng_statedump_file_descriptor,
	74	TP_PROTO(struct lttng_session *session,
	75	struct files_struct *files,
	76	int fd, const char *filename,
	77	unsigned int flags, fmode_t fmode),
	78	TP_ARGS(session, files, fd, filename, flags, fmode));
	79
	80	LTTNG_DEFINE_TRACE(lttng_statedump_start,
	81	TP_PROTO(struct lttng_session *session),
	82	TP_ARGS(session));
	83
	84	LTTNG_DEFINE_TRACE(lttng_statedump_process_state,
	85	TP_PROTO(struct lttng_session *session,
	86	struct task_struct *p,
	87	int type, int mode, int submode, int status,
	88	struct files_struct *files),
	89	TP_ARGS(session, p, type, mode, submode, status, files));
	90
	91	LTTNG_DEFINE_TRACE(lttng_statedump_network_interface,
	92	TP_PROTO(struct lttng_session *session,
	93	struct net_device dev, struct in_ifaddr ifa),
	94	TP_ARGS(session, dev, ifa));
20591cf7	95
361c023a MD	96	struct lttng_fd_ctx {
	97	char *page;
	98	struct lttng_session *session;
	99	struct task_struct *p;
d561ecfb	100	struct files_struct *files;
361c023a MD	101	};
361c023a MD	102
c337ddc2 MD	103	/*
	104	* Protected by the trace lock.
	105	*/
	106	static struct delayed_work cpu_work[NR_CPUS];
	107	static DECLARE_WAIT_QUEUE_HEAD(statedump_wq);
	108	static atomic_t kernel_threads_to_run;
	109
	110	enum lttng_thread_type {
	111	LTTNG_USER_THREAD = 0,
	112	LTTNG_KERNEL_THREAD = 1,
	113	};
	114
	115	enum lttng_execution_mode {
	116	LTTNG_USER_MODE = 0,
	117	LTTNG_SYSCALL = 1,
	118	LTTNG_TRAP = 2,
	119	LTTNG_IRQ = 3,
	120	LTTNG_SOFTIRQ = 4,
	121	LTTNG_MODE_UNKNOWN = 5,
	122	};
	123
	124	enum lttng_execution_submode {
	125	LTTNG_NONE = 0,
	126	LTTNG_UNKNOWN = 1,
	127	};
	128
	129	enum lttng_process_status {
	130	LTTNG_UNNAMED = 0,
	131	LTTNG_WAIT_FORK = 1,
	132	LTTNG_WAIT_CPU = 2,
	133	LTTNG_EXIT = 3,
	134	LTTNG_ZOMBIE = 4,
	135	LTTNG_WAIT = 5,
	136	LTTNG_RUN = 6,
	137	LTTNG_DEAD = 7,
	138	};
	139
f0dbdefb HD	140	static
	141	int lttng_enumerate_block_devices(struct lttng_session *session)
	142	{
	143	struct class *ptr_block_class;
	144	struct device_type *ptr_disk_type;
	145	struct class_dev_iter iter;
	146	struct device *dev;
	147
	148	ptr_block_class = wrapper_get_block_class();
	149	if (!ptr_block_class)
	150	return -ENOSYS;
	151	ptr_disk_type = wrapper_get_disk_type();
	152	if (!ptr_disk_type) {
	153	return -ENOSYS;
	154	}
	155	class_dev_iter_init(&iter, ptr_block_class, NULL, ptr_disk_type);
	156	while ((dev = class_dev_iter_next(&iter))) {
	157	struct disk_part_iter piter;
	158	struct gendisk *disk = dev_to_disk(dev);
	159	struct hd_struct *part;
	160
5a91f3df MD	161	/*
	162	* Don't show empty devices or things that have been
	163	* suppressed
	164	*/
	165	if (get_capacity(disk) == 0 \|\|
	166	(disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
	167	continue;
	168
f0dbdefb HD	169	disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
f0dbdefb HD	170	while ((part = disk_part_iter_next(&piter))) {
bf5a011d	171	struct block_device bdev;
f0dbdefb	172	char name_buf[BDEVNAME_SIZE];
bf5a011d	173	const char *p;
f0dbdefb	174
bf5a011d MJ	175	/*
	176	* Create a partial 'struct blockdevice' to use
	177	* 'bdevname()' which is a simple wrapper over
	178	* 'disk_name()' but has the honor to be EXPORT_SYMBOL.
	179	*/
	180	bdev.bd_disk = disk;
	181	bdev.bd_part = part;
	182
	183	p = bdevname(&bdev, name_buf);
f0dbdefb HD	184	if (!p) {
	185	disk_part_iter_exit(&piter);
	186	class_dev_iter_exit(&iter);
	187	return -ENOSYS;
	188	}
	189	trace_lttng_statedump_block_device(session,
	190	part_devt(part), name_buf);
	191	}
	192	disk_part_iter_exit(&piter);
	193	}
	194	class_dev_iter_exit(&iter);
	195	return 0;
	196	}
	197
c337ddc2	198	#ifdef CONFIG_INET
f0dbdefb	199
c337ddc2 MD	200	static
	201	void lttng_enumerate_device(struct lttng_session *session,
	202	struct net_device *dev)
	203	{
	204	struct in_device *in_dev;
	205	struct in_ifaddr *ifa;
	206
	207	if (dev->flags & IFF_UP) {
	208	in_dev = in_dev_get(dev);
	209	if (in_dev) {
	210	for (ifa = in_dev->ifa_list; ifa != NULL;
	211	ifa = ifa->ifa_next) {
	212	trace_lttng_statedump_network_interface(
	213	session, dev, ifa);
	214	}
	215	in_dev_put(in_dev);
	216	}
	217	} else {
	218	trace_lttng_statedump_network_interface(
	219	session, dev, NULL);
	220	}
	221	}
	222
	223	static
	224	int lttng_enumerate_network_ip_interface(struct lttng_session *session)
	225	{
	226	struct net_device *dev;
	227
	228	read_lock(&dev_base_lock);
	229	for_each_netdev(&init_net, dev)
	230	lttng_enumerate_device(session, dev);
	231	read_unlock(&dev_base_lock);
	232
	233	return 0;
	234	}
	235	#else /* CONFIG_INET */
	236	static inline
	237	int lttng_enumerate_network_ip_interface(struct lttng_session *session)
	238	{
	239	return 0;
	240	}
	241	#endif /* CONFIG_INET */
	242
361c023a MD	243	static
	244	int lttng_dump_one_fd(const void p, struct file file, unsigned int fd)
	245	{
	246	const struct lttng_fd_ctx *ctx = p;
	247	const char *s = d_path(&file->f_path, ctx->page, PAGE_SIZE);
29021503	248	unsigned int flags = file->f_flags;
d561ecfb	249	struct fdtable *fdt;
361c023a	250
29021503 MD	251	/*
	252	* We don't expose kernel internal flags, only userspace-visible
	253	* flags.
	254	*/
	255	flags &= ~FMODE_NONOTIFY;
d561ecfb MD	256	fdt = files_fdtable(ctx->files);
	257	/*
	258	* We need to check here again whether fd is within the fdt
	259	* max_fds range, because we might be seeing a different
	260	* files_fdtable() than iterate_fd(), assuming only RCU is
	261	* protecting the read. In reality, iterate_fd() holds
	262	* file_lock, which should ensure the fdt does not change while
	263	* the lock is taken, but we are not aware whether this is
	264	* guaranteed or not, so play safe.
	265	*/
aa29f2d3	266	if (fd < fdt->max_fds && lttng_close_on_exec(fd, fdt))
29021503	267	flags \|= O_CLOEXEC;
361c023a MD	268	if (IS_ERR(s)) {
	269	struct dentry *dentry = file->f_path.dentry;
	270
	271	/* Make sure we give at least some info */
	272	spin_lock(&dentry->d_lock);
	273	trace_lttng_statedump_file_descriptor(ctx->session, ctx->p, fd,
29021503	274	dentry->d_name.name, flags, file->f_mode);
361c023a MD	275	spin_unlock(&dentry->d_lock);
	276	goto end;
	277	}
29021503 MD	278	trace_lttng_statedump_file_descriptor(ctx->session, ctx->p, fd, s,
29021503 MD	279	flags, file->f_mode);
361c023a MD	280	end:
	281	return 0;
	282	}
c337ddc2 MD	283
	284	static
	285	void lttng_enumerate_task_fd(struct lttng_session *session,
	286	struct task_struct p, char tmp)
	287	{
361c023a	288	struct lttng_fd_ctx ctx = { .page = tmp, .session = session, .p = p };
d561ecfb	289	struct files_struct *files;
c337ddc2 MD	290
c337ddc2 MD	291	task_lock(p);
d561ecfb MD	292	files = p->files;
	293	if (!files)
	294	goto end;
	295	ctx.files = files;
	296	lttng_iterate_fd(files, 0, lttng_dump_one_fd, &ctx);
	297	end:
c337ddc2 MD	298	task_unlock(p);
	299	}
	300
	301	static
	302	int lttng_enumerate_file_descriptors(struct lttng_session *session)
	303	{
	304	struct task_struct *p;
cfcee1c7 MD	305	char *tmp;
	306
	307	tmp = (char *) __get_free_page(GFP_KERNEL);
	308	if (!tmp)
	309	return -ENOMEM;
c337ddc2 MD	310
	311	/* Enumerate active file descriptors */
	312	rcu_read_lock();
	313	for_each_process(p)
	314	lttng_enumerate_task_fd(session, p, tmp);
	315	rcu_read_unlock();
	316	free_page((unsigned long) tmp);
	317	return 0;
	318	}
	319
0658bdda MD	320	#if 0
	321	/*
	322	* FIXME: we cannot take a mmap_sem while in a RCU read-side critical section
	323	* (scheduling in atomic). Normally, the tasklist lock protects this kind of
	324	* iteration, but it is not exported to modules.
	325	*/
c337ddc2 MD	326	static
	327	void lttng_enumerate_task_vm_maps(struct lttng_session *session,
	328	struct task_struct *p)
	329	{
	330	struct mm_struct *mm;
	331	struct vm_area_struct *map;
	332	unsigned long ino;
	333
	334	/* get_task_mm does a task_lock... */
	335	mm = get_task_mm(p);
	336	if (!mm)
	337	return;
	338
	339	map = mm->mmap;
	340	if (map) {
	341	down_read(&mm->mmap_sem);
	342	while (map) {
	343	if (map->vm_file)
b06ed645	344	ino = map->vm_file->lttng_f_dentry->d_inode->i_ino;
c337ddc2 MD	345	else
	346	ino = 0;
	347	trace_lttng_statedump_vm_map(session, p, map, ino);
	348	map = map->vm_next;
	349	}
	350	up_read(&mm->mmap_sem);
	351	}
	352	mmput(mm);
	353	}
	354
	355	static
	356	int lttng_enumerate_vm_maps(struct lttng_session *session)
	357	{
	358	struct task_struct *p;
	359
	360	rcu_read_lock();
	361	for_each_process(p)
	362	lttng_enumerate_task_vm_maps(session, p);
	363	rcu_read_unlock();
	364	return 0;
	365	}
0658bdda	366	#endif
c337ddc2	367
29784493	368	#ifdef CONFIG_LTTNG_HAS_LIST_IRQ
47faec4b JN	369
	370	#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,39))
	371	#define irq_desc_get_chip(desc) get_irq_desc_chip(desc)
	372	#endif
	373
c337ddc2	374	static
cfcee1c7	375	int lttng_list_interrupts(struct lttng_session *session)
c337ddc2 MD	376	{
	377	unsigned int irq;
	378	unsigned long flags = 0;
	379	struct irq_desc *desc;
	380
	381	#define irq_to_desc wrapper_irq_to_desc
	382	/* needs irq_desc */
	383	for_each_irq_desc(irq, desc) {
	384	struct irqaction *action;
	385	const char *irq_chip_name =
	386	irq_desc_get_chip(desc)->name ? : "unnamed_irq_chip";
	387
	388	local_irq_save(flags);
3a523f5b	389	wrapper_desc_spin_lock(&desc->lock);
c337ddc2 MD	390	for (action = desc->action; action; action = action->next) {
	391	trace_lttng_statedump_interrupt(session,
	392	irq, irq_chip_name, action);
	393	}
3a523f5b	394	wrapper_desc_spin_unlock(&desc->lock);
c337ddc2 MD	395	local_irq_restore(flags);
c337ddc2 MD	396	}
cfcee1c7	397	return 0;
c337ddc2 MD	398	#undef irq_to_desc
	399	}
	400	#else
	401	static inline
cfcee1c7	402	int lttng_list_interrupts(struct lttng_session *session)
c337ddc2	403	{
cfcee1c7	404	return 0;
c337ddc2 MD	405	}
	406	#endif
	407
4ba1f53c MD	408	/*
	409	* Called with task lock held.
	410	*/
73e8ba37 JD	411	static
	412	void lttng_statedump_process_ns(struct lttng_session *session,
	413	struct task_struct *p,
	414	enum lttng_thread_type type,
	415	enum lttng_execution_mode mode,
	416	enum lttng_execution_submode submode,
	417	enum lttng_process_status status)
	418	{
73e8ba37 JD	419	struct pid_namespace *pid_ns;
73e8ba37 JD	420
887bcdac MJ	421	pid_ns = task_active_pid_ns(p);
887bcdac MJ	422	do {
73e8ba37	423	trace_lttng_statedump_process_state(session,
887bcdac	424	p, type, mode, submode, status, pid_ns);
d16203a5	425	pid_ns = pid_ns ? pid_ns->parent : NULL;
887bcdac	426	} while (pid_ns);
73e8ba37 JD	427	}
73e8ba37 JD	428
c337ddc2 MD	429	static
	430	int lttng_enumerate_process_states(struct lttng_session *session)
	431	{
	432	struct task_struct g, p;
	433
	434	rcu_read_lock();
	435	for_each_process(g) {
	436	p = g;
	437	do {
	438	enum lttng_execution_mode mode =
	439	LTTNG_MODE_UNKNOWN;
	440	enum lttng_execution_submode submode =
	441	LTTNG_UNKNOWN;
	442	enum lttng_process_status status;
	443	enum lttng_thread_type type;
	444
	445	task_lock(p);
	446	if (p->exit_state == EXIT_ZOMBIE)
	447	status = LTTNG_ZOMBIE;
	448	else if (p->exit_state == EXIT_DEAD)
	449	status = LTTNG_DEAD;
	450	else if (p->state == TASK_RUNNING) {
	451	/* Is this a forked child that has not run yet? */
	452	if (list_empty(&p->rt.run_list))
	453	status = LTTNG_WAIT_FORK;
	454	else
	455	/*
	456	* All tasks are considered as wait_cpu;
	457	* the viewer will sort out if the task
	458	* was really running at this time.
	459	*/
	460	status = LTTNG_WAIT_CPU;
	461	} else if (p->state &
	462	(TASK_INTERRUPTIBLE \| TASK_UNINTERRUPTIBLE)) {
	463	/* Task is waiting for something to complete */
	464	status = LTTNG_WAIT;
	465	} else
	466	status = LTTNG_UNNAMED;
	467	submode = LTTNG_NONE;
	468
	469	/*
	470	* Verification of t->mm is to filter out kernel
	471	* threads; Viewer will further filter out if a
	472	* user-space thread was in syscall mode or not.
	473	*/
	474	if (p->mm)
	475	type = LTTNG_USER_THREAD;
	476	else
	477	type = LTTNG_KERNEL_THREAD;
73e8ba37	478	lttng_statedump_process_ns(session,
c337ddc2 MD	479	p, type, mode, submode, status);
	480	task_unlock(p);
	481	} while_each_thread(g, p);
	482	}
	483	rcu_read_unlock();
	484
	485	return 0;
	486	}
	487
	488	static
	489	void lttng_statedump_work_func(struct work_struct *work)
	490	{
	491	if (atomic_dec_and_test(&kernel_threads_to_run))
	492	/* If we are the last thread, wake up do_lttng_statedump */
	493	wake_up(&statedump_wq);
	494	}
	495
	496	static
	497	int do_lttng_statedump(struct lttng_session *session)
	498	{
cfcee1c7	499	int cpu, ret;
c337ddc2	500
c337ddc2	501	trace_lttng_statedump_start(session);
cfcee1c7 MD	502	ret = lttng_enumerate_process_states(session);
	503	if (ret)
	504	return ret;
	505	ret = lttng_enumerate_file_descriptors(session);
	506	if (ret)
	507	return ret;
	508	/*
	509	* FIXME
	510	* ret = lttng_enumerate_vm_maps(session);
	511	* if (ret)
	512	* return ret;
	513	*/
	514	ret = lttng_list_interrupts(session);
	515	if (ret)
	516	return ret;
	517	ret = lttng_enumerate_network_ip_interface(session);
	518	if (ret)
	519	return ret;
	520	ret = lttng_enumerate_block_devices(session);
	521	switch (ret) {
84c7055e MD	522	case 0:
84c7055e MD	523	break;
cfcee1c7 MD	524	case -ENOSYS:
	525	printk(KERN_WARNING "LTTng: block device enumeration is not supported by kernel\n");
	526	break;
	527	default:
	528	return ret;
	529	}
c337ddc2 MD	530
	531	/* TODO lttng_dump_idt_table(session); */
	532	/* TODO lttng_dump_softirq_vec(session); */
	533	/* TODO lttng_list_modules(session); */
	534	/* TODO lttng_dump_swap_files(session); */
	535
	536	/*
	537	* Fire off a work queue on each CPU. Their sole purpose in life
	538	* is to guarantee that each CPU has been in a state where is was in
	539	* syscall mode (i.e. not in a trap, an IRQ or a soft IRQ).
	540	*/
	541	get_online_cpus();
	542	atomic_set(&kernel_threads_to_run, num_online_cpus());
	543	for_each_online_cpu(cpu) {
	544	INIT_DELAYED_WORK(&cpu_work[cpu], lttng_statedump_work_func);
	545	schedule_delayed_work_on(cpu, &cpu_work[cpu], 0);
	546	}
	547	/* Wait for all threads to run */
7a7128e0	548	__wait_event(statedump_wq, (atomic_read(&kernel_threads_to_run) == 0));
c337ddc2 MD	549	put_online_cpus();
c337ddc2 MD	550	/* Our work is done */
c337ddc2 MD	551	trace_lttng_statedump_end(session);
	552	return 0;
	553	}
	554
	555	/*
	556	* Called with session mutex held.
	557	*/
	558	int lttng_statedump_start(struct lttng_session *session)
	559	{
c337ddc2 MD	560	return do_lttng_statedump(session);
	561	}
	562	EXPORT_SYMBOL_GPL(lttng_statedump_start);
	563
dd8d5afb MD	564	static
	565	int __init lttng_statedump_init(void)
	566	{
d16aa9c9 MD	567	/*
	568	* Allow module to load even if the fixup cannot be done. This
	569	* will allow seemless transition when the underlying issue fix
	570	* is merged into the Linux kernel, and when tracepoint.c
	571	* "tracepoint_module_notify" is turned into a static function.
	572	*/
	573	(void) wrapper_lttng_fixup_sig(THIS_MODULE);
	574	return 0;
dd8d5afb MD	575	}
	576
	577	module_init(lttng_statedump_init);
	578
461277e7 MD	579	static
	580	void __exit lttng_statedump_exit(void)
	581	{
	582	}
	583
	584	module_exit(lttng_statedump_exit);
	585
c337ddc2 MD	586	MODULE_LICENSE("GPL and additional rights");
c337ddc2 MD	587	MODULE_AUTHOR("Jean-Hugues Deschenes");
1c124020	588	MODULE_DESCRIPTION("LTTng statedump provider");
13ab8b0a MD	589	MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
	590	__stringify(LTTNG_MODULES_MINOR_VERSION) "."
	591	__stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
	592	LTTNG_MODULES_EXTRAVERSION);