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

/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
 *
 * 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 <linux/fdtable.h>
#include <linux/irq.h>
#include <linux/genhd.h>

#include <lttng/lttng-events.h>
#include <lttng/lttng-tracer.h>

/* 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_process_pid_ns);
DEFINE_TRACE(lttng_statedump_process_cgroup_ns);
DEFINE_TRACE(lttng_statedump_process_ipc_ns);
#ifndef LTTNG_MNT_NS_MISSING_HEADER
DEFINE_TRACE(lttng_statedump_process_mnt_ns);
#endif
DEFINE_TRACE(lttng_statedump_process_net_ns);
DEFINE_TRACE(lttng_statedump_process_user_ns);
DEFINE_TRACE(lttng_statedump_process_uts_ns);
DEFINE_TRACE(lttng_statedump_network_interface);
#ifdef LTTNG_HAVE_STATEDUMP_CPU_TOPOLOGY
DEFINE_TRACE(lttng_statedump_cpu_topology);
#endif

struct lttng_fd_ctx {
	char *page;
	struct lttng_session *session;
	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_dev_iter iter;
	struct device *dev;

	class_dev_iter_init(&iter, gendisk_block_class(), NULL,
			    gendisk_device_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 = gendisk_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 && 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->files, fd, dentry->d_name.name, flags,
			file->f_mode);
		spin_unlock(&dentry->d_lock);
		goto end;
	}
	trace_lttng_statedump_file_descriptor(ctx->session,
		ctx->files, fd, s, flags, file->f_mode);
end:
	return 0;
}

/* Called with task lock held. */
static
void lttng_enumerate_files(struct lttng_session *session,
		struct files_struct *files,
		char *tmp)
{
	struct lttng_fd_ctx ctx = { .page = tmp, .session = session, .files = files, };

	iterate_fd(files, 0, lttng_dump_one_fd, &ctx);
}

#ifdef LTTNG_HAVE_STATEDUMP_CPU_TOPOLOGY
static
int lttng_enumerate_cpu_topology(struct lttng_session *session)
{
	int cpu;
	const cpumask_t *cpumask = cpu_possible_mask;

	for (cpu = cpumask_first(cpumask); cpu < nr_cpu_ids;
			cpu = cpumask_next(cpu, cpumask)) {
		trace_lttng_statedump_cpu_topology(session, &cpu_data(cpu));
	}

	return 0;
}
#else
static
int lttng_enumerate_cpu_topology(struct lttng_session *session)
{
	return 0;
}
#endif

#if 0
/*
 * FIXME: we cannot take a mmap_sem while in a RCU read-side critical section
 * (scheduling in atomic). Normally, the tasklist lock protects this kind of
 * iteration, but it is not exported to modules.
 */
static
void lttng_enumerate_task_vm_maps(struct lttng_session *session,
		struct task_struct *p)
{
	struct mm_struct *mm;
	struct vm_area_struct *map;
	unsigned long ino;

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

	map = mm->mmap;
	if (map) {
		down_read(&mm->mmap_sem);
		while (map) {
			if (map->vm_file)
				ino = map->vm_file->f_path.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

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

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

		local_irq_save(flags);
		raw_spin_lock(&desc->lock);
		for (action = desc->action; action; action = action->next) {
			trace_lttng_statedump_interrupt(session,
				irq, irq_chip_name, action);
		}
		raw_spin_unlock(&desc->lock);
		local_irq_restore(flags);
	}
	return 0;
}

/*
 * Statedump the task's namespaces using the proc filesystem inode number as
 * the unique identifier. The user and pid ns are nested and will be dumped
 * recursively.
 *
 * 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 nsproxy *proxy;
	struct pid_namespace *pid_ns;
	struct user_namespace *user_ns;

	/*
	 * The pid and user namespaces are special, they are nested and
	 * accessed with specific functions instead of the nsproxy struct
	 * like the other namespaces.
	 */
	pid_ns = task_active_pid_ns(p);
	do {
		trace_lttng_statedump_process_pid_ns(session, p, pid_ns);
		pid_ns = pid_ns ? pid_ns->parent : NULL;
	} while (pid_ns);


	user_ns = task_cred_xxx(p, user_ns);
	do {
		trace_lttng_statedump_process_user_ns(session, p, user_ns);
		/*
		 * trace_lttng_statedump_process_user_ns() internally
		 * checks whether user_ns is NULL. While this does not
		 * appear to be a possible return value for
		 * task_cred_xxx(), err on the safe side and check
		 * for NULL here as well to be consistent with the
		 * paranoid behavior of
		 * trace_lttng_statedump_process_user_ns().
		 */
		user_ns = user_ns ? user_ns->parent : NULL;
	} while (user_ns);

	/*
	 * Back and forth on locking strategy within Linux upstream for nsproxy.
	 * See Linux upstream commit 728dba3a39c66b3d8ac889ddbe38b5b1c264aec3
	 * "namespaces: Use task_lock and not rcu to protect nsproxy"
	 * for details.
	 */
	proxy = p->nsproxy;
	if (proxy) {
		trace_lttng_statedump_process_cgroup_ns(session, p, proxy->cgroup_ns);
		trace_lttng_statedump_process_ipc_ns(session, p, proxy->ipc_ns);
#ifndef LTTNG_MNT_NS_MISSING_HEADER
		trace_lttng_statedump_process_mnt_ns(session, p, proxy->mnt_ns);
#endif
		trace_lttng_statedump_process_net_ns(session, p, proxy->net_ns);
		trace_lttng_statedump_process_uts_ns(session, p, proxy->uts_ns);
	}
}

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

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

	rcu_read_lock();
	for_each_process(g) {
		struct files_struct *prev_files = NULL;

		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;
			struct files_struct *files;

			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;
			files = p->files;

			trace_lttng_statedump_process_state(session,
				p, type, mode, submode, status, files);
			lttng_statedump_process_ns(session,
				p, type, mode, submode, status);
			/*
			 * As an optimisation for the common case, do not
			 * repeat information for the same files_struct in
			 * two consecutive threads. This is the common case
			 * for threads sharing the same fd table. RCU guarantees
			 * that the same files_struct pointer is not re-used
			 * throughout processes/threads iteration.
			 */
			if (files && files != prev_files) {
				lttng_enumerate_files(session, files, tmp);
				prev_files = files;
			}
			task_unlock(p);
		} while_each_thread(g, p);
	}
	rcu_read_unlock();

	free_page((unsigned long) tmp);

	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;
	/*
	 * 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;
	}
	ret = lttng_enumerate_cpu_topology(session);
	if (ret)
		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)
{
	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
b7cdc182	1	/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
9f36eaed	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>
997eff5e	35	#include <linux/fdtable.h>
88eb3d8e	36	#include <linux/irq.h>
6afd444b	37	#include <linux/genhd.h>
c337ddc2	38
b5304713 MD	39	#include <lttng/lttng-events.h>
b5304713 MD	40	#include <lttng/lttng-tracer.h>
c337ddc2	41
c337ddc2 MD	42	/* Define the tracepoints, but do not build the probes */
c337ddc2 MD	43	#define CREATE_TRACE_POINTS
241ae9a8	44	#define TRACE_INCLUDE_PATH instrumentation/events/lttng-module
c337ddc2	45	#define TRACE_INCLUDE_FILE lttng-statedump
3bc29f0a	46	#define LTTNG_INSTRUMENTATION
241ae9a8	47	#include <instrumentation/events/lttng-module/lttng-statedump.h>
c337ddc2	48
f0dbdefb	49	DEFINE_TRACE(lttng_statedump_block_device);
20591cf7 MD	50	DEFINE_TRACE(lttng_statedump_end);
	51	DEFINE_TRACE(lttng_statedump_interrupt);
	52	DEFINE_TRACE(lttng_statedump_file_descriptor);
	53	DEFINE_TRACE(lttng_statedump_start);
	54	DEFINE_TRACE(lttng_statedump_process_state);
1965e6b4	55	DEFINE_TRACE(lttng_statedump_process_pid_ns);
1965e6b4	56	DEFINE_TRACE(lttng_statedump_process_cgroup_ns);
1965e6b4 MJ	57	DEFINE_TRACE(lttng_statedump_process_ipc_ns);
	58	#ifndef LTTNG_MNT_NS_MISSING_HEADER
	59	DEFINE_TRACE(lttng_statedump_process_mnt_ns);
	60	#endif
	61	DEFINE_TRACE(lttng_statedump_process_net_ns);
	62	DEFINE_TRACE(lttng_statedump_process_user_ns);
	63	DEFINE_TRACE(lttng_statedump_process_uts_ns);
20591cf7	64	DEFINE_TRACE(lttng_statedump_network_interface);
d0b55e4c	65	#ifdef LTTNG_HAVE_STATEDUMP_CPU_TOPOLOGY
502e4132 JD	66	DEFINE_TRACE(lttng_statedump_cpu_topology);
502e4132 JD	67	#endif
20591cf7	68
361c023a MD	69	struct lttng_fd_ctx {
	70	char *page;
	71	struct lttng_session *session;
d561ecfb	72	struct files_struct *files;
361c023a MD	73	};
361c023a MD	74
c337ddc2 MD	75	/*
	76	* Protected by the trace lock.
	77	*/
	78	static struct delayed_work cpu_work[NR_CPUS];
	79	static DECLARE_WAIT_QUEUE_HEAD(statedump_wq);
	80	static atomic_t kernel_threads_to_run;
	81
	82	enum lttng_thread_type {
	83	LTTNG_USER_THREAD = 0,
	84	LTTNG_KERNEL_THREAD = 1,
	85	};
	86
	87	enum lttng_execution_mode {
	88	LTTNG_USER_MODE = 0,
	89	LTTNG_SYSCALL = 1,
	90	LTTNG_TRAP = 2,
	91	LTTNG_IRQ = 3,
	92	LTTNG_SOFTIRQ = 4,
	93	LTTNG_MODE_UNKNOWN = 5,
	94	};
	95
	96	enum lttng_execution_submode {
	97	LTTNG_NONE = 0,
	98	LTTNG_UNKNOWN = 1,
	99	};
	100
	101	enum lttng_process_status {
	102	LTTNG_UNNAMED = 0,
	103	LTTNG_WAIT_FORK = 1,
	104	LTTNG_WAIT_CPU = 2,
	105	LTTNG_EXIT = 3,
	106	LTTNG_ZOMBIE = 4,
	107	LTTNG_WAIT = 5,
	108	LTTNG_RUN = 6,
	109	LTTNG_DEAD = 7,
	110	};
	111
f0dbdefb HD	112	static
	113	int lttng_enumerate_block_devices(struct lttng_session *session)
	114	{
f0dbdefb HD	115	struct class_dev_iter iter;
	116	struct device *dev;
	117
6afd444b MD	118	class_dev_iter_init(&iter, gendisk_block_class(), NULL,
6afd444b MD	119	gendisk_device_type());
f0dbdefb HD	120	while ((dev = class_dev_iter_next(&iter))) {
	121	struct disk_part_iter piter;
	122	struct gendisk *disk = dev_to_disk(dev);
	123	struct hd_struct *part;
	124
5a91f3df MD	125	/*
	126	* Don't show empty devices or things that have been
	127	* suppressed
	128	*/
	129	if (get_capacity(disk) == 0 \|\|
	130	(disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
	131	continue;
	132
f0dbdefb HD	133	disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
	134	while ((part = disk_part_iter_next(&piter))) {
	135	char name_buf[BDEVNAME_SIZE];
	136	char *p;
	137
6afd444b	138	p = gendisk_name(disk, part->partno, name_buf);
f0dbdefb HD	139	if (!p) {
	140	disk_part_iter_exit(&piter);
	141	class_dev_iter_exit(&iter);
	142	return -ENOSYS;
	143	}
	144	trace_lttng_statedump_block_device(session,
	145	part_devt(part), name_buf);
	146	}
	147	disk_part_iter_exit(&piter);
	148	}
	149	class_dev_iter_exit(&iter);
	150	return 0;
	151	}
	152
c337ddc2	153	#ifdef CONFIG_INET
f0dbdefb	154
c337ddc2 MD	155	static
	156	void lttng_enumerate_device(struct lttng_session *session,
	157	struct net_device *dev)
	158	{
	159	struct in_device *in_dev;
	160	struct in_ifaddr *ifa;
	161
	162	if (dev->flags & IFF_UP) {
	163	in_dev = in_dev_get(dev);
	164	if (in_dev) {
	165	for (ifa = in_dev->ifa_list; ifa != NULL;
	166	ifa = ifa->ifa_next) {
	167	trace_lttng_statedump_network_interface(
	168	session, dev, ifa);
	169	}
	170	in_dev_put(in_dev);
	171	}
	172	} else {
	173	trace_lttng_statedump_network_interface(
	174	session, dev, NULL);
	175	}
	176	}
	177
	178	static
	179	int lttng_enumerate_network_ip_interface(struct lttng_session *session)
	180	{
	181	struct net_device *dev;
	182
	183	read_lock(&dev_base_lock);
	184	for_each_netdev(&init_net, dev)
	185	lttng_enumerate_device(session, dev);
	186	read_unlock(&dev_base_lock);
	187
	188	return 0;
	189	}
	190	#else /* CONFIG_INET */
	191	static inline
	192	int lttng_enumerate_network_ip_interface(struct lttng_session *session)
	193	{
	194	return 0;
	195	}
	196	#endif /* CONFIG_INET */
	197
361c023a MD	198	static
	199	int lttng_dump_one_fd(const void p, struct file file, unsigned int fd)
	200	{
	201	const struct lttng_fd_ctx *ctx = p;
	202	const char *s = d_path(&file->f_path, ctx->page, PAGE_SIZE);
29021503	203	unsigned int flags = file->f_flags;
d561ecfb	204	struct fdtable *fdt;
361c023a	205
29021503 MD	206	/*
	207	* We don't expose kernel internal flags, only userspace-visible
	208	* flags.
	209	*/
	210	flags &= ~FMODE_NONOTIFY;
d561ecfb MD	211	fdt = files_fdtable(ctx->files);
	212	/*
	213	* We need to check here again whether fd is within the fdt
	214	* max_fds range, because we might be seeing a different
	215	* files_fdtable() than iterate_fd(), assuming only RCU is
	216	* protecting the read. In reality, iterate_fd() holds
	217	* file_lock, which should ensure the fdt does not change while
	218	* the lock is taken, but we are not aware whether this is
	219	* guaranteed or not, so play safe.
	220	*/
997eff5e	221	if (fd < fdt->max_fds && close_on_exec(fd, fdt))
29021503	222	flags \|= O_CLOEXEC;
361c023a MD	223	if (IS_ERR(s)) {
	224	struct dentry *dentry = file->f_path.dentry;
	225
	226	/* Make sure we give at least some info */
	227	spin_lock(&dentry->d_lock);
e7a0ca72 MD	228	trace_lttng_statedump_file_descriptor(ctx->session,
	229	ctx->files, fd, dentry->d_name.name, flags,
	230	file->f_mode);
361c023a MD	231	spin_unlock(&dentry->d_lock);
	232	goto end;
	233	}
e7a0ca72 MD	234	trace_lttng_statedump_file_descriptor(ctx->session,
e7a0ca72 MD	235	ctx->files, fd, s, flags, file->f_mode);
361c023a MD	236	end:
	237	return 0;
	238	}
c337ddc2	239
e7a0ca72	240	/* Called with task lock held. */
c337ddc2	241	static
e7a0ca72 MD	242	void lttng_enumerate_files(struct lttng_session *session,
	243	struct files_struct *files,
	244	char *tmp)
c337ddc2	245	{
e7a0ca72	246	struct lttng_fd_ctx ctx = { .page = tmp, .session = session, .files = files, };
c337ddc2	247
997eff5e	248	iterate_fd(files, 0, lttng_dump_one_fd, &ctx);
c337ddc2 MD	249	}
c337ddc2 MD	250
d0b55e4c	251	#ifdef LTTNG_HAVE_STATEDUMP_CPU_TOPOLOGY
502e4132 JD	252	static
	253	int lttng_enumerate_cpu_topology(struct lttng_session *session)
	254	{
	255	int cpu;
	256	const cpumask_t *cpumask = cpu_possible_mask;
	257
	258	for (cpu = cpumask_first(cpumask); cpu < nr_cpu_ids;
	259	cpu = cpumask_next(cpu, cpumask)) {
	260	trace_lttng_statedump_cpu_topology(session, &cpu_data(cpu));
	261	}
	262
	263	return 0;
	264	}
	265	#else
	266	static
	267	int lttng_enumerate_cpu_topology(struct lttng_session *session)
	268	{
	269	return 0;
	270	}
	271	#endif
	272
0658bdda MD	273	#if 0
	274	/*
	275	* FIXME: we cannot take a mmap_sem while in a RCU read-side critical section
	276	* (scheduling in atomic). Normally, the tasklist lock protects this kind of
	277	* iteration, but it is not exported to modules.
	278	*/
c337ddc2 MD	279	static
	280	void lttng_enumerate_task_vm_maps(struct lttng_session *session,
	281	struct task_struct *p)
	282	{
	283	struct mm_struct *mm;
	284	struct vm_area_struct *map;
	285	unsigned long ino;
	286
	287	/* get_task_mm does a task_lock... */
	288	mm = get_task_mm(p);
	289	if (!mm)
	290	return;
	291
	292	map = mm->mmap;
	293	if (map) {
	294	down_read(&mm->mmap_sem);
	295	while (map) {
	296	if (map->vm_file)
34522739	297	ino = map->vm_file->f_path.dentry->d_inode->i_ino;
c337ddc2 MD	298	else
	299	ino = 0;
	300	trace_lttng_statedump_vm_map(session, p, map, ino);
	301	map = map->vm_next;
	302	}
	303	up_read(&mm->mmap_sem);
	304	}
	305	mmput(mm);
	306	}
	307
	308	static
	309	int lttng_enumerate_vm_maps(struct lttng_session *session)
	310	{
	311	struct task_struct *p;
	312
	313	rcu_read_lock();
	314	for_each_process(p)
	315	lttng_enumerate_task_vm_maps(session, p);
	316	rcu_read_unlock();
	317	return 0;
	318	}
0658bdda	319	#endif
c337ddc2	320
c337ddc2	321	static
cfcee1c7	322	int lttng_list_interrupts(struct lttng_session *session)
c337ddc2 MD	323	{
	324	unsigned int irq;
	325	unsigned long flags = 0;
	326	struct irq_desc *desc;
	327
c337ddc2 MD	328	/* needs irq_desc */
	329	for_each_irq_desc(irq, desc) {
	330	struct irqaction *action;
	331	const char *irq_chip_name =
	332	irq_desc_get_chip(desc)->name ? : "unnamed_irq_chip";
	333
	334	local_irq_save(flags);
fc94c945	335	raw_spin_lock(&desc->lock);
c337ddc2 MD	336	for (action = desc->action; action; action = action->next) {
	337	trace_lttng_statedump_interrupt(session,
	338	irq, irq_chip_name, action);
	339	}
fc94c945	340	raw_spin_unlock(&desc->lock);
c337ddc2 MD	341	local_irq_restore(flags);
c337ddc2 MD	342	}
cfcee1c7	343	return 0;
c337ddc2	344	}
c337ddc2	345
4ba1f53c	346	/*
1965e6b4 MJ	347	* Statedump the task's namespaces using the proc filesystem inode number as
	348	* the unique identifier. The user and pid ns are nested and will be dumped
	349	* recursively.
	350	*
4ba1f53c MD	351	* Called with task lock held.
4ba1f53c MD	352	*/
73e8ba37 JD	353	static
	354	void lttng_statedump_process_ns(struct lttng_session *session,
	355	struct task_struct *p,
	356	enum lttng_thread_type type,
	357	enum lttng_execution_mode mode,
	358	enum lttng_execution_submode submode,
	359	enum lttng_process_status status)
	360	{
1965e6b4	361	struct nsproxy *proxy;
73e8ba37	362	struct pid_namespace *pid_ns;
1965e6b4	363	struct user_namespace *user_ns;
73e8ba37	364
1965e6b4 MJ	365	/*
	366	* The pid and user namespaces are special, they are nested and
	367	* accessed with specific functions instead of the nsproxy struct
	368	* like the other namespaces.
	369	*/
887bcdac MJ	370	pid_ns = task_active_pid_ns(p);
887bcdac MJ	371	do {
1965e6b4	372	trace_lttng_statedump_process_pid_ns(session, p, pid_ns);
adcc8b5e	373	pid_ns = pid_ns ? pid_ns->parent : NULL;
887bcdac	374	} while (pid_ns);
1965e6b4 MJ	375
	376
	377	user_ns = task_cred_xxx(p, user_ns);
	378	do {
	379	trace_lttng_statedump_process_user_ns(session, p, user_ns);
1964cccb MD	380	/*
	381	* trace_lttng_statedump_process_user_ns() internally
	382	* checks whether user_ns is NULL. While this does not
	383	* appear to be a possible return value for
	384	* task_cred_xxx(), err on the safe side and check
	385	* for NULL here as well to be consistent with the
	386	* paranoid behavior of
	387	* trace_lttng_statedump_process_user_ns().
	388	*/
6388029c	389	user_ns = user_ns ? user_ns->parent : NULL;
1965e6b4 MJ	390	} while (user_ns);
	391
	392	/*
	393	* Back and forth on locking strategy within Linux upstream for nsproxy.
	394	* See Linux upstream commit 728dba3a39c66b3d8ac889ddbe38b5b1c264aec3
	395	* "namespaces: Use task_lock and not rcu to protect nsproxy"
	396	* for details.
	397	*/
1965e6b4	398	proxy = p->nsproxy;
1965e6b4	399	if (proxy) {
1965e6b4	400	trace_lttng_statedump_process_cgroup_ns(session, p, proxy->cgroup_ns);
1965e6b4 MJ	401	trace_lttng_statedump_process_ipc_ns(session, p, proxy->ipc_ns);
	402	#ifndef LTTNG_MNT_NS_MISSING_HEADER
	403	trace_lttng_statedump_process_mnt_ns(session, p, proxy->mnt_ns);
	404	#endif
	405	trace_lttng_statedump_process_net_ns(session, p, proxy->net_ns);
	406	trace_lttng_statedump_process_uts_ns(session, p, proxy->uts_ns);
	407	}
73e8ba37 JD	408	}
73e8ba37 JD	409
c337ddc2 MD	410	static
	411	int lttng_enumerate_process_states(struct lttng_session *session)
	412	{
	413	struct task_struct g, p;
e7a0ca72 MD	414	char *tmp;
	415
	416	tmp = (char *) __get_free_page(GFP_KERNEL);
	417	if (!tmp)
	418	return -ENOMEM;
c337ddc2 MD	419
	420	rcu_read_lock();
	421	for_each_process(g) {
e7a0ca72 MD	422	struct files_struct *prev_files = NULL;
e7a0ca72 MD	423
c337ddc2 MD	424	p = g;
	425	do {
	426	enum lttng_execution_mode mode =
	427	LTTNG_MODE_UNKNOWN;
	428	enum lttng_execution_submode submode =
	429	LTTNG_UNKNOWN;
	430	enum lttng_process_status status;
	431	enum lttng_thread_type type;
e7a0ca72	432	struct files_struct *files;
c337ddc2 MD	433
	434	task_lock(p);
	435	if (p->exit_state == EXIT_ZOMBIE)
	436	status = LTTNG_ZOMBIE;
	437	else if (p->exit_state == EXIT_DEAD)
	438	status = LTTNG_DEAD;
	439	else if (p->state == TASK_RUNNING) {
	440	/* Is this a forked child that has not run yet? */
	441	if (list_empty(&p->rt.run_list))
	442	status = LTTNG_WAIT_FORK;
	443	else
	444	/*
	445	* All tasks are considered as wait_cpu;
	446	* the viewer will sort out if the task
	447	* was really running at this time.
	448	*/
	449	status = LTTNG_WAIT_CPU;
	450	} else if (p->state &
	451	(TASK_INTERRUPTIBLE \| TASK_UNINTERRUPTIBLE)) {
	452	/* Task is waiting for something to complete */
	453	status = LTTNG_WAIT;
	454	} else
	455	status = LTTNG_UNNAMED;
	456	submode = LTTNG_NONE;
	457
	458	/*
	459	* Verification of t->mm is to filter out kernel
	460	* threads; Viewer will further filter out if a
	461	* user-space thread was in syscall mode or not.
	462	*/
	463	if (p->mm)
	464	type = LTTNG_USER_THREAD;
	465	else
	466	type = LTTNG_KERNEL_THREAD;
e7a0ca72	467	files = p->files;
d2a927ac MJ	468
d2a927ac MJ	469	trace_lttng_statedump_process_state(session,
e7a0ca72	470	p, type, mode, submode, status, files);
73e8ba37	471	lttng_statedump_process_ns(session,
c337ddc2	472	p, type, mode, submode, status);
e7a0ca72 MD	473	/*
	474	* As an optimisation for the common case, do not
	475	* repeat information for the same files_struct in
	476	* two consecutive threads. This is the common case
	477	* for threads sharing the same fd table. RCU guarantees
	478	* that the same files_struct pointer is not re-used
	479	* throughout processes/threads iteration.
	480	*/
	481	if (files && files != prev_files) {
	482	lttng_enumerate_files(session, files, tmp);
	483	prev_files = files;
	484	}
c337ddc2 MD	485	task_unlock(p);
	486	} while_each_thread(g, p);
	487	}
	488	rcu_read_unlock();
	489
e7a0ca72 MD	490	free_page((unsigned long) tmp);
e7a0ca72 MD	491
c337ddc2 MD	492	return 0;
	493	}
	494
	495	static
	496	void lttng_statedump_work_func(struct work_struct *work)
	497	{
	498	if (atomic_dec_and_test(&kernel_threads_to_run))
	499	/* If we are the last thread, wake up do_lttng_statedump */
	500	wake_up(&statedump_wq);
	501	}
	502
	503	static
	504	int do_lttng_statedump(struct lttng_session *session)
	505	{
cfcee1c7	506	int cpu, ret;
c337ddc2	507
c337ddc2	508	trace_lttng_statedump_start(session);
cfcee1c7	509	ret = lttng_enumerate_process_states(session);
cfcee1c7 MD	510	if (ret)
	511	return ret;
	512	/*
	513	* FIXME
	514	* ret = lttng_enumerate_vm_maps(session);
	515	* if (ret)
	516	* return ret;
	517	*/
	518	ret = lttng_list_interrupts(session);
	519	if (ret)
	520	return ret;
	521	ret = lttng_enumerate_network_ip_interface(session);
	522	if (ret)
	523	return ret;
	524	ret = lttng_enumerate_block_devices(session);
	525	switch (ret) {
84c7055e MD	526	case 0:
84c7055e MD	527	break;
cfcee1c7 MD	528	case -ENOSYS:
	529	printk(KERN_WARNING "LTTng: block device enumeration is not supported by kernel\n");
	530	break;
	531	default:
	532	return ret;
	533	}
502e4132 JD	534	ret = lttng_enumerate_cpu_topology(session);
	535	if (ret)
	536	return ret;
c337ddc2 MD	537
	538	/* TODO lttng_dump_idt_table(session); */
	539	/* TODO lttng_dump_softirq_vec(session); */
	540	/* TODO lttng_list_modules(session); */
	541	/* TODO lttng_dump_swap_files(session); */
	542
	543	/*
	544	* Fire off a work queue on each CPU. Their sole purpose in life
	545	* is to guarantee that each CPU has been in a state where is was in
	546	* syscall mode (i.e. not in a trap, an IRQ or a soft IRQ).
	547	*/
	548	get_online_cpus();
	549	atomic_set(&kernel_threads_to_run, num_online_cpus());
	550	for_each_online_cpu(cpu) {
	551	INIT_DELAYED_WORK(&cpu_work[cpu], lttng_statedump_work_func);
	552	schedule_delayed_work_on(cpu, &cpu_work[cpu], 0);
	553	}
	554	/* Wait for all threads to run */
7a7128e0	555	__wait_event(statedump_wq, (atomic_read(&kernel_threads_to_run) == 0));
c337ddc2 MD	556	put_online_cpus();
c337ddc2 MD	557	/* Our work is done */
c337ddc2 MD	558	trace_lttng_statedump_end(session);
	559	return 0;
	560	}
	561
	562	/*
	563	* Called with session mutex held.
	564	*/
	565	int lttng_statedump_start(struct lttng_session *session)
	566	{
c337ddc2 MD	567	return do_lttng_statedump(session);
	568	}
	569	EXPORT_SYMBOL_GPL(lttng_statedump_start);
	570
dd8d5afb MD	571	static
	572	int __init lttng_statedump_init(void)
	573	{
d16aa9c9	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);