lttng-statedump-impl.c

   1 /* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
   2  *
   3  * lttng-statedump.c
   4  *
   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
  14  */
  15
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/netlink.h>
  19 #include <linux/inet.h>
  20 #include <linux/ip.h>
  21 #include <linux/kthread.h>
  22 #include <linux/proc_fs.h>
  23 #include <linux/file.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/irqnr.h>
  26 #include <linux/cpu.h>
  27 #include <linux/netdevice.h>
  28 #include <linux/inetdevice.h>
  29 #include <linux/sched.h>
  30 #include <linux/mm.h>
  31 #include <linux/swap.h>
  32 #include <linux/wait.h>
  33 #include <linux/mutex.h>
  34 #include <linux/device.h>
  35
  36 #include <lttng-events.h>
  37 #include <lttng-tracer.h>
  38 #include <wrapper/irqdesc.h>
  39 #include <wrapper/fdtable.h>
  40 #include <wrapper/namespace.h>
  41 #include <wrapper/irq.h>
  42 #include <wrapper/tracepoint.h>
  43 #include <wrapper/genhd.h>
  44 #include <wrapper/file.h>
  45 #include <wrapper/fdtable.h>
  46
  47 #ifdef CONFIG_LTTNG_HAS_LIST_IRQ
  48 #include <linux/irq.h>
  49 #endif
  50
  51 /* Define the tracepoints, but do not build the probes */
  52 #define CREATE_TRACE_POINTS
  53 #define TRACE_INCLUDE_PATH instrumentation/events/lttng-module
  54 #define TRACE_INCLUDE_FILE lttng-statedump
  55 #define LTTNG_INSTRUMENTATION
  56 #include <instrumentation/events/lttng-module/lttng-statedump.h>
  57
  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_process_pid_ns,
  92         TP_PROTO(struct lttng_session *session,
  93                 struct task_struct *p,
  94                 struct pid_namespace *pid_ns),
  95         TP_ARGS(session, p, pid_ns));
  96
  97 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,6,0))
  98 LTTNG_DEFINE_TRACE(lttng_statedump_process_cgroup_ns,
  99         TP_PROTO(struct lttng_session *session,
 100                 struct task_struct *p,
 101                 struct cgroup_namespace *cgroup_ns),
 102         TP_ARGS(session, p, cgroup_ns));
 103 #endif
 104
 105 LTTNG_DEFINE_TRACE(lttng_statedump_process_ipc_ns,
 106         TP_PROTO(struct lttng_session *session,
 107                 struct task_struct *p,
 108                 struct ipc_namespace *ipc_ns),
 109         TP_ARGS(session, p, ipc_ns));
 110
 111 #ifndef LTTNG_MNT_NS_MISSING_HEADER
 112 LTTNG_DEFINE_TRACE(lttng_statedump_process_mnt_ns,
 113         TP_PROTO(struct lttng_session *session,
 114                 struct task_struct *p,
 115                 struct mnt_namespace *mnt_ns),
 116         TP_ARGS(session, p, mnt_ns));
 117 #endif
 118
 119 LTTNG_DEFINE_TRACE(lttng_statedump_process_net_ns,
 120         TP_PROTO(struct lttng_session *session,
 121                 struct task_struct *p,
 122                 struct net *net_ns),
 123         TP_ARGS(session, p, net_ns));
 124
 125 LTTNG_DEFINE_TRACE(lttng_statedump_process_user_ns,
 126         TP_PROTO(struct lttng_session *session,
 127                 struct task_struct *p,
 128                 struct user_namespace *user_ns),
 129         TP_ARGS(session, p, user_ns));
 130
 131 LTTNG_DEFINE_TRACE(lttng_statedump_process_uts_ns,
 132         TP_PROTO(struct lttng_session *session,
 133                 struct task_struct *p,
 134                 struct uts_namespace *uts_ns),
 135         TP_ARGS(session, p, uts_ns));
 136
 137 LTTNG_DEFINE_TRACE(lttng_statedump_network_interface,
 138         TP_PROTO(struct lttng_session *session,
 139                 struct net_device *dev, struct in_ifaddr *ifa),
 140         TP_ARGS(session, dev, ifa));
 141
 142 #ifdef LTTNG_HAVE_STATEDUMP_CPU_TOPOLOGY
 143 LTTNG_DEFINE_TRACE(lttng_statedump_cpu_topology,
 144         TP_PROTO(struct lttng_session *session, struct cpuinfo_x86 *c),
 145         TP_ARGS(session, c));
 146 #endif
 147
 148 struct lttng_fd_ctx {
 149         char *page;
 150         struct lttng_session *session;
 151         struct files_struct *files;
 152 };
 153
 154 /*
 155  * Protected by the trace lock.
 156  */
 157 static struct delayed_work cpu_work[NR_CPUS];
 158 static DECLARE_WAIT_QUEUE_HEAD(statedump_wq);
 159 static atomic_t kernel_threads_to_run;
 160
 161 enum lttng_thread_type {
 162         LTTNG_USER_THREAD = 0,
 163         LTTNG_KERNEL_THREAD = 1,
 164 };
 165
 166 enum lttng_execution_mode {
 167         LTTNG_USER_MODE = 0,
 168         LTTNG_SYSCALL = 1,
 169         LTTNG_TRAP = 2,
 170         LTTNG_IRQ = 3,
 171         LTTNG_SOFTIRQ = 4,
 172         LTTNG_MODE_UNKNOWN = 5,
 173 };
 174
 175 enum lttng_execution_submode {
 176         LTTNG_NONE = 0,
 177         LTTNG_UNKNOWN = 1,
 178 };
 179
 180 enum lttng_process_status {
 181         LTTNG_UNNAMED = 0,
 182         LTTNG_WAIT_FORK = 1,
 183         LTTNG_WAIT_CPU = 2,
 184         LTTNG_EXIT = 3,
 185         LTTNG_ZOMBIE = 4,
 186         LTTNG_WAIT = 5,
 187         LTTNG_RUN = 6,
 188         LTTNG_DEAD = 7,
 189 };
 190
 191 static
 192 int lttng_enumerate_block_devices(struct lttng_session *session)
 193 {
 194         struct class *ptr_block_class;
 195         struct device_type *ptr_disk_type;
 196         struct class_dev_iter iter;
 197         struct device *dev;
 198
 199         ptr_block_class = wrapper_get_block_class();
 200         if (!ptr_block_class)
 201                 return -ENOSYS;
 202         ptr_disk_type = wrapper_get_disk_type();
 203         if (!ptr_disk_type) {
 204                 return -ENOSYS;
 205         }
 206         class_dev_iter_init(&iter, ptr_block_class, NULL, ptr_disk_type);
 207         while ((dev = class_dev_iter_next(&iter))) {
 208                 struct disk_part_iter piter;
 209                 struct gendisk *disk = dev_to_disk(dev);
 210                 struct hd_struct *part;
 211
 212                 /*
 213                  * Don't show empty devices or things that have been
 214                  * suppressed
 215                  */
 216                 if (get_capacity(disk) == 0 ||
 217                     (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
 218                         continue;
 219
 220                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 221                 while ((part = disk_part_iter_next(&piter))) {
 222                         struct block_device bdev;
 223                         char name_buf[BDEVNAME_SIZE];
 224                         const char *p;
 225
 226                         /*
 227                          * Create a partial 'struct blockdevice' to use
 228                          * 'bdevname()' which is a simple wrapper over
 229                          * 'disk_name()' but has the honor to be EXPORT_SYMBOL.
 230                          */
 231                         bdev.bd_disk = disk;
 232                         bdev.bd_part = part;
 233
 234                         p = bdevname(&bdev, name_buf);
 235                         if (!p) {
 236                                 disk_part_iter_exit(&piter);
 237                                 class_dev_iter_exit(&iter);
 238                                 return -ENOSYS;
 239                         }
 240                         trace_lttng_statedump_block_device(session,
 241                                         part_devt(part), name_buf);
 242                 }
 243                 disk_part_iter_exit(&piter);
 244         }
 245         class_dev_iter_exit(&iter);
 246         return 0;
 247 }
 248
 249 #ifdef CONFIG_INET
 250
 251 static
 252 void lttng_enumerate_device(struct lttng_session *session,
 253                 struct net_device *dev)
 254 {
 255         struct in_device *in_dev;
 256         struct in_ifaddr *ifa;
 257
 258         if (dev->flags & IFF_UP) {
 259                 in_dev = in_dev_get(dev);
 260                 if (in_dev) {
 261                         for (ifa = in_dev->ifa_list; ifa != NULL;
 262                              ifa = ifa->ifa_next) {
 263                                 trace_lttng_statedump_network_interface(
 264                                         session, dev, ifa);
 265                         }
 266                         in_dev_put(in_dev);
 267                 }
 268         } else {
 269                 trace_lttng_statedump_network_interface(
 270                         session, dev, NULL);
 271         }
 272 }
 273
 274 static
 275 int lttng_enumerate_network_ip_interface(struct lttng_session *session)
 276 {
 277         struct net_device *dev;
 278
 279         read_lock(&dev_base_lock);
 280         for_each_netdev(&init_net, dev)
 281                 lttng_enumerate_device(session, dev);
 282         read_unlock(&dev_base_lock);
 283
 284         return 0;
 285 }
 286 #else /* CONFIG_INET */
 287 static inline
 288 int lttng_enumerate_network_ip_interface(struct lttng_session *session)
 289 {
 290         return 0;
 291 }
 292 #endif /* CONFIG_INET */
 293
 294 static
 295 int lttng_dump_one_fd(const void *p, struct file *file, unsigned int fd)
 296 {
 297         const struct lttng_fd_ctx *ctx = p;
 298         const char *s = d_path(&file->f_path, ctx->page, PAGE_SIZE);
 299         unsigned int flags = file->f_flags;
 300         struct fdtable *fdt;
 301
 302         /*
 303          * We don't expose kernel internal flags, only userspace-visible
 304          * flags.
 305          */
 306         flags &= ~FMODE_NONOTIFY;
 307         fdt = files_fdtable(ctx->files);
 308         /*
 309          * We need to check here again whether fd is within the fdt
 310          * max_fds range, because we might be seeing a different
 311          * files_fdtable() than iterate_fd(), assuming only RCU is
 312          * protecting the read. In reality, iterate_fd() holds
 313          * file_lock, which should ensure the fdt does not change while
 314          * the lock is taken, but we are not aware whether this is
 315          * guaranteed or not, so play safe.
 316          */
 317         if (fd < fdt->max_fds && lttng_close_on_exec(fd, fdt))
 318                 flags |= O_CLOEXEC;
 319         if (IS_ERR(s)) {
 320                 struct dentry *dentry = file->f_path.dentry;
 321
 322                 /* Make sure we give at least some info */
 323                 spin_lock(&dentry->d_lock);
 324                 trace_lttng_statedump_file_descriptor(ctx->session,
 325                         ctx->files, fd, dentry->d_name.name, flags,
 326                         file->f_mode);
 327                 spin_unlock(&dentry->d_lock);
 328                 goto end;
 329         }
 330         trace_lttng_statedump_file_descriptor(ctx->session,
 331                 ctx->files, fd, s, flags, file->f_mode);
 332 end:
 333         return 0;
 334 }
 335
 336 /* Called with task lock held. */
 337 static
 338 void lttng_enumerate_files(struct lttng_session *session,
 339                 struct files_struct *files,
 340                 char *tmp)
 341 {
 342         struct lttng_fd_ctx ctx = { .page = tmp, .session = session, .files = files, };
 343
 344         lttng_iterate_fd(files, 0, lttng_dump_one_fd, &ctx);
 345 }
 346
 347 #ifdef LTTNG_HAVE_STATEDUMP_CPU_TOPOLOGY
 348 static
 349 int lttng_enumerate_cpu_topology(struct lttng_session *session)
 350 {
 351         int cpu;
 352         const cpumask_t *cpumask = cpu_possible_mask;
 353
 354         for (cpu = cpumask_first(cpumask); cpu < nr_cpu_ids;
 355                         cpu = cpumask_next(cpu, cpumask)) {
 356                 trace_lttng_statedump_cpu_topology(session, &cpu_data(cpu));
 357         }
 358
 359         return 0;
 360 }
 361 #else
 362 static
 363 int lttng_enumerate_cpu_topology(struct lttng_session *session)
 364 {
 365         return 0;
 366 }
 367 #endif
 368
 369 #if 0
 370 /*
 371  * FIXME: we cannot take a mmap_sem while in a RCU read-side critical section
 372  * (scheduling in atomic). Normally, the tasklist lock protects this kind of
 373  * iteration, but it is not exported to modules.
 374  */
 375 static
 376 void lttng_enumerate_task_vm_maps(struct lttng_session *session,
 377                 struct task_struct *p)
 378 {
 379         struct mm_struct *mm;
 380         struct vm_area_struct *map;
 381         unsigned long ino;
 382
 383         /* get_task_mm does a task_lock... */
 384         mm = get_task_mm(p);
 385         if (!mm)
 386                 return;
 387
 388         map = mm->mmap;
 389         if (map) {
 390                 down_read(&mm->mmap_sem);
 391                 while (map) {
 392                         if (map->vm_file)
 393                                 ino = map->vm_file->lttng_f_dentry->d_inode->i_ino;
 394                         else
 395                                 ino = 0;
 396                         trace_lttng_statedump_vm_map(session, p, map, ino);
 397                         map = map->vm_next;
 398                 }
 399                 up_read(&mm->mmap_sem);
 400         }
 401         mmput(mm);
 402 }
 403
 404 static
 405 int lttng_enumerate_vm_maps(struct lttng_session *session)
 406 {
 407         struct task_struct *p;
 408
 409         rcu_read_lock();
 410         for_each_process(p)
 411                 lttng_enumerate_task_vm_maps(session, p);
 412         rcu_read_unlock();
 413         return 0;
 414 }
 415 #endif
 416
 417 #ifdef CONFIG_LTTNG_HAS_LIST_IRQ
 418
 419 static
 420 int lttng_list_interrupts(struct lttng_session *session)
 421 {
 422         unsigned int irq;
 423         unsigned long flags = 0;
 424         struct irq_desc *desc;
 425
 426 #define irq_to_desc     wrapper_irq_to_desc
 427         /* needs irq_desc */
 428         for_each_irq_desc(irq, desc) {
 429                 struct irqaction *action;
 430                 const char *irq_chip_name =
 431                         irq_desc_get_chip(desc)->name ? : "unnamed_irq_chip";
 432
 433                 local_irq_save(flags);
 434                 raw_spin_lock(&desc->lock);
 435                 for (action = desc->action; action; action = action->next) {
 436                         trace_lttng_statedump_interrupt(session,
 437                                 irq, irq_chip_name, action);
 438                 }
 439                 raw_spin_unlock(&desc->lock);
 440                 local_irq_restore(flags);
 441         }
 442         return 0;
 443 #undef irq_to_desc
 444 }
 445 #else
 446 static inline
 447 int lttng_list_interrupts(struct lttng_session *session)
 448 {
 449         return 0;
 450 }
 451 #endif
 452
 453 /*
 454  * Statedump the task's namespaces using the proc filesystem inode number as
 455  * the unique identifier. The user and pid ns are nested and will be dumped
 456  * recursively.
 457  *
 458  * Called with task lock held.
 459  */
 460 static
 461 void lttng_statedump_process_ns(struct lttng_session *session,
 462                 struct task_struct *p,
 463                 enum lttng_thread_type type,
 464                 enum lttng_execution_mode mode,
 465                 enum lttng_execution_submode submode,
 466                 enum lttng_process_status status)
 467 {
 468         struct nsproxy *proxy;
 469         struct pid_namespace *pid_ns;
 470         struct user_namespace *user_ns;
 471
 472         /*
 473          * The pid and user namespaces are special, they are nested and
 474          * accessed with specific functions instead of the nsproxy struct
 475          * like the other namespaces.
 476          */
 477         pid_ns = task_active_pid_ns(p);
 478         do {
 479                 trace_lttng_statedump_process_pid_ns(session, p, pid_ns);
 480                 pid_ns = pid_ns ? pid_ns->parent : NULL;
 481         } while (pid_ns);
 482
 483
 484         user_ns = task_cred_xxx(p, user_ns);
 485         do {
 486                 trace_lttng_statedump_process_user_ns(session, p, user_ns);
 487                 /*
 488                  * trace_lttng_statedump_process_user_ns() internally
 489                  * checks whether user_ns is NULL. While this does not
 490                  * appear to be a possible return value for
 491                  * task_cred_xxx(), err on the safe side and check
 492                  * for NULL here as well to be consistent with the
 493                  * paranoid behavior of
 494                  * trace_lttng_statedump_process_user_ns().
 495                  */
 496                 user_ns = user_ns ? user_ns->lttng_user_ns_parent : NULL;
 497         } while (user_ns);
 498
 499         /*
 500          * Back and forth on locking strategy within Linux upstream for nsproxy.
 501          * See Linux upstream commit 728dba3a39c66b3d8ac889ddbe38b5b1c264aec3
 502          * "namespaces: Use task_lock and not rcu to protect nsproxy"
 503          * for details.
 504          */
 505 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0) || \
 506                 LTTNG_UBUNTU_KERNEL_RANGE(3,13,11,36, 3,14,0,0) || \
 507                 LTTNG_UBUNTU_KERNEL_RANGE(3,16,1,11, 3,17,0,0) || \
 508                 LTTNG_RHEL_KERNEL_RANGE(3,10,0,229,13,0, 3,11,0,0,0,0))
 509         proxy = p->nsproxy;
 510 #else
 511         rcu_read_lock();
 512         proxy = task_nsproxy(p);
 513 #endif
 514         if (proxy) {
 515 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,6,0))
 516                 trace_lttng_statedump_process_cgroup_ns(session, p, proxy->cgroup_ns);
 517 #endif
 518                 trace_lttng_statedump_process_ipc_ns(session, p, proxy->ipc_ns);
 519 #ifndef LTTNG_MNT_NS_MISSING_HEADER
 520                 trace_lttng_statedump_process_mnt_ns(session, p, proxy->mnt_ns);
 521 #endif
 522                 trace_lttng_statedump_process_net_ns(session, p, proxy->net_ns);
 523                 trace_lttng_statedump_process_uts_ns(session, p, proxy->uts_ns);
 524         }
 525 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0) || \
 526                 LTTNG_UBUNTU_KERNEL_RANGE(3,13,11,36, 3,14,0,0) || \
 527                 LTTNG_UBUNTU_KERNEL_RANGE(3,16,1,11, 3,17,0,0) || \
 528                 LTTNG_RHEL_KERNEL_RANGE(3,10,0,229,13,0, 3,11,0,0,0,0))
 529         /* (nothing) */
 530 #else
 531         rcu_read_unlock();
 532 #endif
 533 }
 534
 535 static
 536 int lttng_enumerate_process_states(struct lttng_session *session)
 537 {
 538         struct task_struct *g, *p;
 539         char *tmp;
 540
 541         tmp = (char *) __get_free_page(GFP_KERNEL);
 542         if (!tmp)
 543                 return -ENOMEM;
 544
 545         rcu_read_lock();
 546         for_each_process(g) {
 547                 struct files_struct *prev_files = NULL;
 548
 549                 p = g;
 550                 do {
 551                         enum lttng_execution_mode mode =
 552                                 LTTNG_MODE_UNKNOWN;
 553                         enum lttng_execution_submode submode =
 554                                 LTTNG_UNKNOWN;
 555                         enum lttng_process_status status;
 556                         enum lttng_thread_type type;
 557                         struct files_struct *files;
 558
 559                         task_lock(p);
 560                         if (p->exit_state == EXIT_ZOMBIE)
 561                                 status = LTTNG_ZOMBIE;
 562                         else if (p->exit_state == EXIT_DEAD)
 563                                 status = LTTNG_DEAD;
 564                         else if (p->state == TASK_RUNNING) {
 565                                 /* Is this a forked child that has not run yet? */
 566                                 if (list_empty(&p->rt.run_list))
 567                                         status = LTTNG_WAIT_FORK;
 568                                 else
 569                                         /*
 570                                          * All tasks are considered as wait_cpu;
 571                                          * the viewer will sort out if the task
 572                                          * was really running at this time.
 573                                          */
 574                                         status = LTTNG_WAIT_CPU;
 575                         } else if (p->state &
 576                                 (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)) {
 577                                 /* Task is waiting for something to complete */
 578                                 status = LTTNG_WAIT;
 579                         } else
 580                                 status = LTTNG_UNNAMED;
 581                         submode = LTTNG_NONE;
 582
 583                         /*
 584                          * Verification of t->mm is to filter out kernel
 585                          * threads; Viewer will further filter out if a
 586                          * user-space thread was in syscall mode or not.
 587                          */
 588                         if (p->mm)
 589                                 type = LTTNG_USER_THREAD;
 590                         else
 591                                 type = LTTNG_KERNEL_THREAD;
 592                         files = p->files;
 593
 594                         trace_lttng_statedump_process_state(session,
 595                                 p, type, mode, submode, status, files);
 596                         lttng_statedump_process_ns(session,
 597                                 p, type, mode, submode, status);
 598                         /*
 599                          * As an optimisation for the common case, do not
 600                          * repeat information for the same files_struct in
 601                          * two consecutive threads. This is the common case
 602                          * for threads sharing the same fd table. RCU guarantees
 603                          * that the same files_struct pointer is not re-used
 604                          * throughout processes/threads iteration.
 605                          */
 606                         if (files && files != prev_files) {
 607                                 lttng_enumerate_files(session, files, tmp);
 608                                 prev_files = files;
 609                         }
 610                         task_unlock(p);
 611                 } while_each_thread(g, p);
 612         }
 613         rcu_read_unlock();
 614
 615         free_page((unsigned long) tmp);
 616
 617         return 0;
 618 }
 619
 620 static
 621 void lttng_statedump_work_func(struct work_struct *work)
 622 {
 623         if (atomic_dec_and_test(&kernel_threads_to_run))
 624                 /* If we are the last thread, wake up do_lttng_statedump */
 625                 wake_up(&statedump_wq);
 626 }
 627
 628 static
 629 int do_lttng_statedump(struct lttng_session *session)
 630 {
 631         int cpu, ret;
 632
 633         trace_lttng_statedump_start(session);
 634         ret = lttng_enumerate_process_states(session);
 635         if (ret)
 636                 return ret;
 637         /*
 638          * FIXME
 639          * ret = lttng_enumerate_vm_maps(session);
 640          * if (ret)
 641          *      return ret;
 642          */
 643         ret = lttng_list_interrupts(session);
 644         if (ret)
 645                 return ret;
 646         ret = lttng_enumerate_network_ip_interface(session);
 647         if (ret)
 648                 return ret;
 649         ret = lttng_enumerate_block_devices(session);
 650         switch (ret) {
 651         case 0:
 652                 break;
 653         case -ENOSYS:
 654                 printk(KERN_WARNING "LTTng: block device enumeration is not supported by kernel\n");
 655                 break;
 656         default:
 657                 return ret;
 658         }
 659         ret = lttng_enumerate_cpu_topology(session);
 660         if (ret)
 661                 return ret;
 662
 663         /* TODO lttng_dump_idt_table(session); */
 664         /* TODO lttng_dump_softirq_vec(session); */
 665         /* TODO lttng_list_modules(session); */
 666         /* TODO lttng_dump_swap_files(session); */
 667
 668         /*
 669          * Fire off a work queue on each CPU. Their sole purpose in life
 670          * is to guarantee that each CPU has been in a state where is was in
 671          * syscall mode (i.e. not in a trap, an IRQ or a soft IRQ).
 672          */
 673         get_online_cpus();
 674         atomic_set(&kernel_threads_to_run, num_online_cpus());
 675         for_each_online_cpu(cpu) {
 676                 INIT_DELAYED_WORK(&cpu_work[cpu], lttng_statedump_work_func);
 677                 schedule_delayed_work_on(cpu, &cpu_work[cpu], 0);
 678         }
 679         /* Wait for all threads to run */
 680         __wait_event(statedump_wq, (atomic_read(&kernel_threads_to_run) == 0));
 681         put_online_cpus();
 682         /* Our work is done */
 683         trace_lttng_statedump_end(session);
 684         return 0;
 685 }
 686
 687 /*
 688  * Called with session mutex held.
 689  */
 690 int lttng_statedump_start(struct lttng_session *session)
 691 {
 692         return do_lttng_statedump(session);
 693 }
 694 EXPORT_SYMBOL_GPL(lttng_statedump_start);
 695
 696 static
 697 int __init lttng_statedump_init(void)
 698 {
 699         /*
 700          * Allow module to load even if the fixup cannot be done. This
 701          * will allow seemless transition when the underlying issue fix
 702          * is merged into the Linux kernel, and when tracepoint.c
 703          * "tracepoint_module_notify" is turned into a static function.
 704          */
 705         (void) wrapper_lttng_fixup_sig(THIS_MODULE);
 706         return 0;
 707 }
 708
 709 module_init(lttng_statedump_init);
 710
 711 static
 712 void __exit lttng_statedump_exit(void)
 713 {
 714 }
 715
 716 module_exit(lttng_statedump_exit);
 717
 718 MODULE_LICENSE("GPL and additional rights");
 719 MODULE_AUTHOR("Jean-Hugues Deschenes");
 720 MODULE_DESCRIPTION("LTTng statedump provider");
 721 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
 722         __stringify(LTTNG_MODULES_MINOR_VERSION) "."
 723         __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
 724         LTTNG_MODULES_EXTRAVERSION);