[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 task_struct *p, int fd, const char *filename,
		unsigned int flags, fmode_t fmode),
	TP_ARGS(session, p, 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 pid_namespace *pid_ns),
	TP_ARGS(session, p, type, mode, submode, status, pid_ns));

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,
};


#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,11,0))

#define LTTNG_PART_STRUCT_TYPE struct block_device

static
int lttng_get_part_name(struct gendisk *disk, struct block_device *part, char *name_buf)
{
	const char *p;

	p = bdevname(part, name_buf);
	if (!p)
		return -ENOSYS;

	return 0;
}

static
dev_t lttng_get_part_devt(struct block_device *part)
{
	return part->bd_dev;
}

#else

#define LTTNG_PART_STRUCT_TYPE struct hd_struct

static
int lttng_get_part_name(struct gendisk *disk, struct hd_struct *part, char *name_buf)
{
	const char *p;
	struct block_device bdev;

	/*
	 * 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)
		return -ENOSYS;

	return 0;
}

static
dev_t lttng_get_part_devt(struct hd_struct *part)
{
	return part_devt(part);
}
#endif

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;
	int ret = 0;

	ptr_block_class = wrapper_get_block_class();
	if (!ptr_block_class) {
		ret = -ENOSYS;
		goto end;
	}
	ptr_disk_type = wrapper_get_disk_type();
	if (!ptr_disk_type) {
		ret = -ENOSYS;
		goto end;
	}
	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);
		LTTNG_PART_STRUCT_TYPE *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;

		/*
		 * The original 'disk_part_iter_init' returns void, but our
		 * wrapper can fail to lookup the original symbol.
		 */
		if (wrapper_disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0) < 0) {
			ret = -ENOSYS;
			goto iter_exit;
		}

		while ((part = wrapper_disk_part_iter_next(&piter))) {
			char name_buf[BDEVNAME_SIZE];

			if (lttng_get_part_name(disk, part, name_buf) == -ENOSYS) {
				wrapper_disk_part_iter_exit(&piter);
				ret = -ENOSYS;
				goto iter_exit;
			}
			trace_lttng_statedump_block_device(session,
					lttng_get_part_devt(part), name_buf);
		}
		wrapper_disk_part_iter_exit(&piter);
	}
iter_exit:
	class_dev_iter_exit(&iter);
end:
	return ret;
}

#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 (LTTNG_LINUX_VERSION_CODE < LTTNG_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,
f8922333	75	struct task_struct p, int fd, const char filename,
c6b31b34	76	unsigned int flags, fmode_t fmode),
f8922333	77	TP_ARGS(session, p, fd, filename, flags, fmode));
c6b31b34 MJ	78
	79	LTTNG_DEFINE_TRACE(lttng_statedump_start,
	80	TP_PROTO(struct lttng_session *session),
	81	TP_ARGS(session));
	82
	83	LTTNG_DEFINE_TRACE(lttng_statedump_process_state,
	84	TP_PROTO(struct lttng_session *session,
	85	struct task_struct *p,
	86	int type, int mode, int submode, int status,
f8922333 MJ	87	struct pid_namespace *pid_ns),
f8922333 MJ	88	TP_ARGS(session, p, type, mode, submode, status, pid_ns));
c6b31b34 MJ	89
	90	LTTNG_DEFINE_TRACE(lttng_statedump_network_interface,
	91	TP_PROTO(struct lttng_session *session,
	92	struct net_device dev, struct in_ifaddr ifa),
	93	TP_ARGS(session, dev, ifa));
20591cf7	94
361c023a MD	95	struct lttng_fd_ctx {
	96	char *page;
	97	struct lttng_session *session;
	98	struct task_struct *p;
d561ecfb	99	struct files_struct *files;
361c023a MD	100	};
361c023a MD	101
c337ddc2 MD	102	/*
	103	* Protected by the trace lock.
	104	*/
	105	static struct delayed_work cpu_work[NR_CPUS];
	106	static DECLARE_WAIT_QUEUE_HEAD(statedump_wq);
	107	static atomic_t kernel_threads_to_run;
	108
	109	enum lttng_thread_type {
	110	LTTNG_USER_THREAD = 0,
	111	LTTNG_KERNEL_THREAD = 1,
	112	};
	113
	114	enum lttng_execution_mode {
	115	LTTNG_USER_MODE = 0,
	116	LTTNG_SYSCALL = 1,
	117	LTTNG_TRAP = 2,
	118	LTTNG_IRQ = 3,
	119	LTTNG_SOFTIRQ = 4,
	120	LTTNG_MODE_UNKNOWN = 5,
	121	};
	122
	123	enum lttng_execution_submode {
	124	LTTNG_NONE = 0,
	125	LTTNG_UNKNOWN = 1,
	126	};
	127
	128	enum lttng_process_status {
	129	LTTNG_UNNAMED = 0,
	130	LTTNG_WAIT_FORK = 1,
	131	LTTNG_WAIT_CPU = 2,
	132	LTTNG_EXIT = 3,
	133	LTTNG_ZOMBIE = 4,
	134	LTTNG_WAIT = 5,
	135	LTTNG_RUN = 6,
	136	LTTNG_DEAD = 7,
	137	};
	138
6bcf4dc1	139
b78104db	140	#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,11,0))
6bcf4dc1 MJ	141
	142	#define LTTNG_PART_STRUCT_TYPE struct block_device
	143
	144	static
	145	int lttng_get_part_name(struct gendisk disk, struct block_device part, char *name_buf)
	146	{
	147	const char *p;
	148
	149	p = bdevname(part, name_buf);
	150	if (!p)
	151	return -ENOSYS;
	152
	153	return 0;
	154	}
	155
	156	static
	157	dev_t lttng_get_part_devt(struct block_device *part)
	158	{
	159	return part->bd_dev;
	160	}
	161
	162	#else
	163
	164	#define LTTNG_PART_STRUCT_TYPE struct hd_struct
	165
	166	static
	167	int lttng_get_part_name(struct gendisk disk, struct hd_struct part, char *name_buf)
	168	{
	169	const char *p;
	170	struct block_device bdev;
	171
	172	/*
	173	* Create a partial 'struct blockdevice' to use
	174	* 'bdevname()' which is a simple wrapper over
	175	* 'disk_name()' but has the honor to be EXPORT_SYMBOL.
	176	*/
	177	bdev.bd_disk = disk;
	178	bdev.bd_part = part;
	179
	180	p = bdevname(&bdev, name_buf);
	181	if (!p)
	182	return -ENOSYS;
	183
	184	return 0;
	185	}
	186
	187	static
	188	dev_t lttng_get_part_devt(struct hd_struct *part)
	189	{
	190	return part_devt(part);
	191	}
	192	#endif
	193
f0dbdefb HD	194	static
	195	int lttng_enumerate_block_devices(struct lttng_session *session)
	196	{
	197	struct class *ptr_block_class;
	198	struct device_type *ptr_disk_type;
	199	struct class_dev_iter iter;
	200	struct device *dev;
aeb71057	201	int ret = 0;
f0dbdefb HD	202
f0dbdefb HD	203	ptr_block_class = wrapper_get_block_class();
aeb71057 MJ	204	if (!ptr_block_class) {
	205	ret = -ENOSYS;
	206	goto end;
	207	}
f0dbdefb HD	208	ptr_disk_type = wrapper_get_disk_type();
f0dbdefb HD	209	if (!ptr_disk_type) {
aeb71057 MJ	210	ret = -ENOSYS;
aeb71057 MJ	211	goto end;
f0dbdefb HD	212	}
	213	class_dev_iter_init(&iter, ptr_block_class, NULL, ptr_disk_type);
	214	while ((dev = class_dev_iter_next(&iter))) {
	215	struct disk_part_iter piter;
	216	struct gendisk *disk = dev_to_disk(dev);
6bcf4dc1	217	LTTNG_PART_STRUCT_TYPE *part;
f0dbdefb	218
5a91f3df MD	219	/*
	220	* Don't show empty devices or things that have been
	221	* suppressed
	222	*/
	223	if (get_capacity(disk) == 0 \|\|
	224	(disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
	225	continue;
	226
aeb71057 MJ	227	/*
	228	* The original 'disk_part_iter_init' returns void, but our
	229	* wrapper can fail to lookup the original symbol.
	230	*/
	231	if (wrapper_disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0) < 0) {
	232	ret = -ENOSYS;
	233	goto iter_exit;
	234	}
	235
	236	while ((part = wrapper_disk_part_iter_next(&piter))) {
f0dbdefb	237	char name_buf[BDEVNAME_SIZE];
6bcf4dc1 MJ	238
6bcf4dc1 MJ	239	if (lttng_get_part_name(disk, part, name_buf) == -ENOSYS) {
aeb71057 MJ	240	wrapper_disk_part_iter_exit(&piter);
	241	ret = -ENOSYS;
	242	goto iter_exit;
f0dbdefb HD	243	}
f0dbdefb HD	244	trace_lttng_statedump_block_device(session,
6bcf4dc1	245	lttng_get_part_devt(part), name_buf);
f0dbdefb	246	}
aeb71057	247	wrapper_disk_part_iter_exit(&piter);
f0dbdefb	248	}
aeb71057	249	iter_exit:
f0dbdefb	250	class_dev_iter_exit(&iter);
aeb71057 MJ	251	end:
aeb71057 MJ	252	return ret;
f0dbdefb HD	253	}
f0dbdefb HD	254
c337ddc2	255	#ifdef CONFIG_INET
f0dbdefb	256
c337ddc2 MD	257	static
	258	void lttng_enumerate_device(struct lttng_session *session,
	259	struct net_device *dev)
	260	{
	261	struct in_device *in_dev;
	262	struct in_ifaddr *ifa;
	263
	264	if (dev->flags & IFF_UP) {
	265	in_dev = in_dev_get(dev);
	266	if (in_dev) {
	267	for (ifa = in_dev->ifa_list; ifa != NULL;
	268	ifa = ifa->ifa_next) {
	269	trace_lttng_statedump_network_interface(
	270	session, dev, ifa);
	271	}
	272	in_dev_put(in_dev);
	273	}
	274	} else {
	275	trace_lttng_statedump_network_interface(
	276	session, dev, NULL);
	277	}
	278	}
	279
	280	static
	281	int lttng_enumerate_network_ip_interface(struct lttng_session *session)
	282	{
	283	struct net_device *dev;
	284
	285	read_lock(&dev_base_lock);
	286	for_each_netdev(&init_net, dev)
	287	lttng_enumerate_device(session, dev);
	288	read_unlock(&dev_base_lock);
	289
	290	return 0;
	291	}
	292	#else /* CONFIG_INET */
	293	static inline
	294	int lttng_enumerate_network_ip_interface(struct lttng_session *session)
	295	{
	296	return 0;
	297	}
	298	#endif /* CONFIG_INET */
	299
361c023a MD	300	static
	301	int lttng_dump_one_fd(const void p, struct file file, unsigned int fd)
	302	{
	303	const struct lttng_fd_ctx *ctx = p;
	304	const char *s = d_path(&file->f_path, ctx->page, PAGE_SIZE);
29021503	305	unsigned int flags = file->f_flags;
d561ecfb	306	struct fdtable *fdt;
361c023a	307
29021503 MD	308	/*
	309	* We don't expose kernel internal flags, only userspace-visible
	310	* flags.
	311	*/
	312	flags &= ~FMODE_NONOTIFY;
d561ecfb MD	313	fdt = files_fdtable(ctx->files);
	314	/*
	315	* We need to check here again whether fd is within the fdt
	316	* max_fds range, because we might be seeing a different
	317	* files_fdtable() than iterate_fd(), assuming only RCU is
	318	* protecting the read. In reality, iterate_fd() holds
	319	* file_lock, which should ensure the fdt does not change while
	320	* the lock is taken, but we are not aware whether this is
	321	* guaranteed or not, so play safe.
	322	*/
aa29f2d3	323	if (fd < fdt->max_fds && lttng_close_on_exec(fd, fdt))
29021503	324	flags \|= O_CLOEXEC;
361c023a MD	325	if (IS_ERR(s)) {
	326	struct dentry *dentry = file->f_path.dentry;
	327
	328	/* Make sure we give at least some info */
	329	spin_lock(&dentry->d_lock);
	330	trace_lttng_statedump_file_descriptor(ctx->session, ctx->p, fd,
29021503	331	dentry->d_name.name, flags, file->f_mode);
361c023a MD	332	spin_unlock(&dentry->d_lock);
	333	goto end;
	334	}
29021503 MD	335	trace_lttng_statedump_file_descriptor(ctx->session, ctx->p, fd, s,
29021503 MD	336	flags, file->f_mode);
361c023a MD	337	end:
	338	return 0;
	339	}
c337ddc2 MD	340
	341	static
	342	void lttng_enumerate_task_fd(struct lttng_session *session,
	343	struct task_struct p, char tmp)
	344	{
361c023a	345	struct lttng_fd_ctx ctx = { .page = tmp, .session = session, .p = p };
d561ecfb	346	struct files_struct *files;
c337ddc2 MD	347
c337ddc2 MD	348	task_lock(p);
d561ecfb MD	349	files = p->files;
	350	if (!files)
	351	goto end;
	352	ctx.files = files;
	353	lttng_iterate_fd(files, 0, lttng_dump_one_fd, &ctx);
	354	end:
c337ddc2 MD	355	task_unlock(p);
	356	}
	357
	358	static
	359	int lttng_enumerate_file_descriptors(struct lttng_session *session)
	360	{
	361	struct task_struct *p;
cfcee1c7 MD	362	char *tmp;
	363
	364	tmp = (char *) __get_free_page(GFP_KERNEL);
	365	if (!tmp)
	366	return -ENOMEM;
c337ddc2 MD	367
	368	/* Enumerate active file descriptors */
	369	rcu_read_lock();
	370	for_each_process(p)
	371	lttng_enumerate_task_fd(session, p, tmp);
	372	rcu_read_unlock();
	373	free_page((unsigned long) tmp);
	374	return 0;
	375	}
	376
0658bdda MD	377	#if 0
	378	/*
	379	* FIXME: we cannot take a mmap_sem while in a RCU read-side critical section
	380	* (scheduling in atomic). Normally, the tasklist lock protects this kind of
	381	* iteration, but it is not exported to modules.
	382	*/
c337ddc2 MD	383	static
	384	void lttng_enumerate_task_vm_maps(struct lttng_session *session,
	385	struct task_struct *p)
	386	{
	387	struct mm_struct *mm;
	388	struct vm_area_struct *map;
	389	unsigned long ino;
	390
	391	/* get_task_mm does a task_lock... */
	392	mm = get_task_mm(p);
	393	if (!mm)
	394	return;
	395
	396	map = mm->mmap;
	397	if (map) {
	398	down_read(&mm->mmap_sem);
	399	while (map) {
	400	if (map->vm_file)
b06ed645	401	ino = map->vm_file->lttng_f_dentry->d_inode->i_ino;
c337ddc2 MD	402	else
	403	ino = 0;
	404	trace_lttng_statedump_vm_map(session, p, map, ino);
	405	map = map->vm_next;
	406	}
	407	up_read(&mm->mmap_sem);
	408	}
	409	mmput(mm);
	410	}
	411
	412	static
	413	int lttng_enumerate_vm_maps(struct lttng_session *session)
	414	{
	415	struct task_struct *p;
	416
	417	rcu_read_lock();
	418	for_each_process(p)
	419	lttng_enumerate_task_vm_maps(session, p);
	420	rcu_read_unlock();
	421	return 0;
	422	}
0658bdda	423	#endif
c337ddc2	424
29784493	425	#ifdef CONFIG_LTTNG_HAS_LIST_IRQ
47faec4b	426
b78104db	427	#if (LTTNG_LINUX_VERSION_CODE < LTTNG_KERNEL_VERSION(2,6,39))
47faec4b JN	428	#define irq_desc_get_chip(desc) get_irq_desc_chip(desc)
	429	#endif
	430
c337ddc2	431	static
cfcee1c7	432	int lttng_list_interrupts(struct lttng_session *session)
c337ddc2 MD	433	{
	434	unsigned int irq;
	435	unsigned long flags = 0;
	436	struct irq_desc *desc;
	437
	438	#define irq_to_desc wrapper_irq_to_desc
	439	/* needs irq_desc */
	440	for_each_irq_desc(irq, desc) {
	441	struct irqaction *action;
	442	const char *irq_chip_name =
	443	irq_desc_get_chip(desc)->name ? : "unnamed_irq_chip";
	444
	445	local_irq_save(flags);
3a523f5b	446	wrapper_desc_spin_lock(&desc->lock);
c337ddc2 MD	447	for (action = desc->action; action; action = action->next) {
	448	trace_lttng_statedump_interrupt(session,
	449	irq, irq_chip_name, action);
	450	}
3a523f5b	451	wrapper_desc_spin_unlock(&desc->lock);
c337ddc2 MD	452	local_irq_restore(flags);
c337ddc2 MD	453	}
cfcee1c7	454	return 0;
c337ddc2 MD	455	#undef irq_to_desc
	456	}
	457	#else
	458	static inline
cfcee1c7	459	int lttng_list_interrupts(struct lttng_session *session)
c337ddc2	460	{
cfcee1c7	461	return 0;
c337ddc2 MD	462	}
	463	#endif
	464
4ba1f53c MD	465	/*
	466	* Called with task lock held.
	467	*/
73e8ba37 JD	468	static
	469	void lttng_statedump_process_ns(struct lttng_session *session,
	470	struct task_struct *p,
	471	enum lttng_thread_type type,
	472	enum lttng_execution_mode mode,
	473	enum lttng_execution_submode submode,
	474	enum lttng_process_status status)
	475	{
73e8ba37 JD	476	struct pid_namespace *pid_ns;
73e8ba37 JD	477
887bcdac MJ	478	pid_ns = task_active_pid_ns(p);
887bcdac MJ	479	do {
73e8ba37	480	trace_lttng_statedump_process_state(session,
887bcdac	481	p, type, mode, submode, status, pid_ns);
d16203a5	482	pid_ns = pid_ns ? pid_ns->parent : NULL;
887bcdac	483	} while (pid_ns);
73e8ba37 JD	484	}
73e8ba37 JD	485
c337ddc2 MD	486	static
	487	int lttng_enumerate_process_states(struct lttng_session *session)
	488	{
	489	struct task_struct g, p;
	490
	491	rcu_read_lock();
	492	for_each_process(g) {
	493	p = g;
	494	do {
	495	enum lttng_execution_mode mode =
	496	LTTNG_MODE_UNKNOWN;
	497	enum lttng_execution_submode submode =
	498	LTTNG_UNKNOWN;
	499	enum lttng_process_status status;
	500	enum lttng_thread_type type;
	501
	502	task_lock(p);
	503	if (p->exit_state == EXIT_ZOMBIE)
	504	status = LTTNG_ZOMBIE;
	505	else if (p->exit_state == EXIT_DEAD)
	506	status = LTTNG_DEAD;
	507	else if (p->state == TASK_RUNNING) {
	508	/* Is this a forked child that has not run yet? */
	509	if (list_empty(&p->rt.run_list))
	510	status = LTTNG_WAIT_FORK;
	511	else
	512	/*
	513	* All tasks are considered as wait_cpu;
	514	* the viewer will sort out if the task
	515	* was really running at this time.
	516	*/
	517	status = LTTNG_WAIT_CPU;
	518	} else if (p->state &
	519	(TASK_INTERRUPTIBLE \| TASK_UNINTERRUPTIBLE)) {
	520	/* Task is waiting for something to complete */
	521	status = LTTNG_WAIT;
	522	} else
	523	status = LTTNG_UNNAMED;
	524	submode = LTTNG_NONE;
	525
	526	/*
	527	* Verification of t->mm is to filter out kernel
	528	* threads; Viewer will further filter out if a
	529	* user-space thread was in syscall mode or not.
	530	*/
	531	if (p->mm)
	532	type = LTTNG_USER_THREAD;
	533	else
	534	type = LTTNG_KERNEL_THREAD;
73e8ba37	535	lttng_statedump_process_ns(session,
c337ddc2 MD	536	p, type, mode, submode, status);
	537	task_unlock(p);
	538	} while_each_thread(g, p);
	539	}
	540	rcu_read_unlock();
	541
	542	return 0;
	543	}
	544
	545	static
	546	void lttng_statedump_work_func(struct work_struct *work)
	547	{
	548	if (atomic_dec_and_test(&kernel_threads_to_run))
	549	/* If we are the last thread, wake up do_lttng_statedump */
	550	wake_up(&statedump_wq);
	551	}
	552
	553	static
	554	int do_lttng_statedump(struct lttng_session *session)
	555	{
cfcee1c7	556	int cpu, ret;
c337ddc2	557
c337ddc2	558	trace_lttng_statedump_start(session);
cfcee1c7 MD	559	ret = lttng_enumerate_process_states(session);
	560	if (ret)
	561	return ret;
	562	ret = lttng_enumerate_file_descriptors(session);
	563	if (ret)
	564	return ret;
	565	/*
	566	* FIXME
	567	* ret = lttng_enumerate_vm_maps(session);
	568	* if (ret)
	569	* return ret;
	570	*/
	571	ret = lttng_list_interrupts(session);
	572	if (ret)
	573	return ret;
	574	ret = lttng_enumerate_network_ip_interface(session);
	575	if (ret)
	576	return ret;
	577	ret = lttng_enumerate_block_devices(session);
	578	switch (ret) {
84c7055e MD	579	case 0:
84c7055e MD	580	break;
cfcee1c7 MD	581	case -ENOSYS:
	582	printk(KERN_WARNING "LTTng: block device enumeration is not supported by kernel\n");
	583	break;
	584	default:
	585	return ret;
	586	}
c337ddc2 MD	587
	588	/* TODO lttng_dump_idt_table(session); */
	589	/* TODO lttng_dump_softirq_vec(session); */
	590	/* TODO lttng_list_modules(session); */
	591	/* TODO lttng_dump_swap_files(session); */
	592
	593	/*
	594	* Fire off a work queue on each CPU. Their sole purpose in life
	595	* is to guarantee that each CPU has been in a state where is was in
	596	* syscall mode (i.e. not in a trap, an IRQ or a soft IRQ).
	597	*/
	598	get_online_cpus();
	599	atomic_set(&kernel_threads_to_run, num_online_cpus());
	600	for_each_online_cpu(cpu) {
	601	INIT_DELAYED_WORK(&cpu_work[cpu], lttng_statedump_work_func);
	602	schedule_delayed_work_on(cpu, &cpu_work[cpu], 0);
	603	}
	604	/* Wait for all threads to run */
7a7128e0	605	__wait_event(statedump_wq, (atomic_read(&kernel_threads_to_run) == 0));
c337ddc2 MD	606	put_online_cpus();
c337ddc2 MD	607	/* Our work is done */
c337ddc2 MD	608	trace_lttng_statedump_end(session);
	609	return 0;
	610	}
	611
	612	/*
	613	* Called with session mutex held.
	614	*/
	615	int lttng_statedump_start(struct lttng_session *session)
	616	{
c337ddc2 MD	617	return do_lttng_statedump(session);
	618	}
	619	EXPORT_SYMBOL_GPL(lttng_statedump_start);
	620
dd8d5afb MD	621	static
	622	int __init lttng_statedump_init(void)
	623	{
d16aa9c9 MD	624	/*
	625	* Allow module to load even if the fixup cannot be done. This
	626	* will allow seemless transition when the underlying issue fix
	627	* is merged into the Linux kernel, and when tracepoint.c
	628	* "tracepoint_module_notify" is turned into a static function.
	629	*/
	630	(void) wrapper_lttng_fixup_sig(THIS_MODULE);
	631	return 0;
dd8d5afb MD	632	}
	633
	634	module_init(lttng_statedump_init);
	635
461277e7 MD	636	static
	637	void __exit lttng_statedump_exit(void)
	638	{
	639	}
	640
	641	module_exit(lttng_statedump_exit);
	642
c337ddc2 MD	643	MODULE_LICENSE("GPL and additional rights");
c337ddc2 MD	644	MODULE_AUTHOR("Jean-Hugues Deschenes");
1c124020	645	MODULE_DESCRIPTION("LTTng statedump provider");
13ab8b0a MD	646	MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
	647	__stringify(LTTNG_MODULES_MINOR_VERSION) "."
	648	__stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
	649	LTTNG_MODULES_EXTRAVERSION);