lttng-statedump-impl.c

   1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
   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
  54 #define TRACE_INCLUDE_FILE lttng-statedump
  55 #define LTTNG_INSTRUMENTATION
  56 #include <instrumentation/events/lttng-statedump.h>
  57
  58 DEFINE_TRACE(lttng_statedump_block_device);
  59 DEFINE_TRACE(lttng_statedump_end);
  60 DEFINE_TRACE(lttng_statedump_interrupt);
  61 DEFINE_TRACE(lttng_statedump_file_descriptor);
  62 DEFINE_TRACE(lttng_statedump_start);
  63 DEFINE_TRACE(lttng_statedump_process_state);
  64 DEFINE_TRACE(lttng_statedump_process_pid_ns);
  65 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,6,0))
  66 DEFINE_TRACE(lttng_statedump_process_cgroup_ns);
  67 #endif
  68 DEFINE_TRACE(lttng_statedump_process_ipc_ns);
  69 #ifndef LTTNG_MNT_NS_MISSING_HEADER
  70 DEFINE_TRACE(lttng_statedump_process_mnt_ns);
  71 #endif
  72 DEFINE_TRACE(lttng_statedump_process_net_ns);
  73 DEFINE_TRACE(lttng_statedump_process_user_ns);
  74 DEFINE_TRACE(lttng_statedump_process_uts_ns);
  75 DEFINE_TRACE(lttng_statedump_network_interface);
  76 #ifdef LTTNG_HAVE_STATEDUMP_CPU_TOPOLOGY
  77 DEFINE_TRACE(lttng_statedump_cpu_topology);
  78 #endif
  79
  80 struct lttng_fd_ctx {
  81         char *page;
  82         struct lttng_session *session;
  83         struct files_struct *files;
  84 };
  85
  86 /*
  87  * Protected by the trace lock.
  88  */
  89 static struct delayed_work cpu_work[NR_CPUS];
  90 static DECLARE_WAIT_QUEUE_HEAD(statedump_wq);
  91 static atomic_t kernel_threads_to_run;
  92
  93 enum lttng_thread_type {
  94         LTTNG_USER_THREAD = 0,
  95         LTTNG_KERNEL_THREAD = 1,
  96 };
  97
  98 enum lttng_execution_mode {
  99         LTTNG_USER_MODE = 0,
 100         LTTNG_SYSCALL = 1,
 101         LTTNG_TRAP = 2,
 102         LTTNG_IRQ = 3,
 103         LTTNG_SOFTIRQ = 4,
 104         LTTNG_MODE_UNKNOWN = 5,
 105 };
 106
 107 enum lttng_execution_submode {
 108         LTTNG_NONE = 0,
 109         LTTNG_UNKNOWN = 1,
 110 };
 111
 112 enum lttng_process_status {
 113         LTTNG_UNNAMED = 0,
 114         LTTNG_WAIT_FORK = 1,
 115         LTTNG_WAIT_CPU = 2,
 116         LTTNG_EXIT = 3,
 117         LTTNG_ZOMBIE = 4,
 118         LTTNG_WAIT = 5,
 119         LTTNG_RUN = 6,
 120         LTTNG_DEAD = 7,
 121 };
 122
 123 static
 124 int lttng_enumerate_block_devices(struct lttng_session *session)
 125 {
 126         struct class *ptr_block_class;
 127         struct device_type *ptr_disk_type;
 128         struct class_dev_iter iter;
 129         struct device *dev;
 130
 131         ptr_block_class = wrapper_get_block_class();
 132         if (!ptr_block_class)
 133                 return -ENOSYS;
 134         ptr_disk_type = wrapper_get_disk_type();
 135         if (!ptr_disk_type) {
 136                 return -ENOSYS;
 137         }
 138         class_dev_iter_init(&iter, ptr_block_class, NULL, ptr_disk_type);
 139         while ((dev = class_dev_iter_next(&iter))) {
 140                 struct disk_part_iter piter;
 141                 struct gendisk *disk = dev_to_disk(dev);
 142                 struct hd_struct *part;
 143
 144                 /*
 145                  * Don't show empty devices or things that have been
 146                  * suppressed
 147                  */
 148                 if (get_capacity(disk) == 0 ||
 149                     (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
 150                         continue;
 151
 152                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 153                 while ((part = disk_part_iter_next(&piter))) {
 154                         char name_buf[BDEVNAME_SIZE];
 155                         char *p;
 156
 157                         p = wrapper_disk_name(disk, part->partno, name_buf);
 158                         if (!p) {
 159                                 disk_part_iter_exit(&piter);
 160                                 class_dev_iter_exit(&iter);
 161                                 return -ENOSYS;
 162                         }
 163                         trace_lttng_statedump_block_device(session,
 164                                         part_devt(part), name_buf);
 165                 }
 166                 disk_part_iter_exit(&piter);
 167         }
 168         class_dev_iter_exit(&iter);
 169         return 0;
 170 }
 171
 172 #ifdef CONFIG_INET
 173
 174 static
 175 void lttng_enumerate_device(struct lttng_session *session,
 176                 struct net_device *dev)
 177 {
 178         struct in_device *in_dev;
 179         struct in_ifaddr *ifa;
 180
 181         if (dev->flags & IFF_UP) {
 182                 in_dev = in_dev_get(dev);
 183                 if (in_dev) {
 184                         for (ifa = in_dev->ifa_list; ifa != NULL;
 185                              ifa = ifa->ifa_next) {
 186                                 trace_lttng_statedump_network_interface(
 187                                         session, dev, ifa);
 188                         }
 189                         in_dev_put(in_dev);
 190                 }
 191         } else {
 192                 trace_lttng_statedump_network_interface(
 193                         session, dev, NULL);
 194         }
 195 }
 196
 197 static
 198 int lttng_enumerate_network_ip_interface(struct lttng_session *session)
 199 {
 200         struct net_device *dev;
 201
 202         read_lock(&dev_base_lock);
 203         for_each_netdev(&init_net, dev)
 204                 lttng_enumerate_device(session, dev);
 205         read_unlock(&dev_base_lock);
 206
 207         return 0;
 208 }
 209 #else /* CONFIG_INET */
 210 static inline
 211 int lttng_enumerate_network_ip_interface(struct lttng_session *session)
 212 {
 213         return 0;
 214 }
 215 #endif /* CONFIG_INET */
 216
 217 static
 218 int lttng_dump_one_fd(const void *p, struct file *file, unsigned int fd)
 219 {
 220         const struct lttng_fd_ctx *ctx = p;
 221         const char *s = d_path(&file->f_path, ctx->page, PAGE_SIZE);
 222         unsigned int flags = file->f_flags;
 223         struct fdtable *fdt;
 224
 225         /*
 226          * We don't expose kernel internal flags, only userspace-visible
 227          * flags.
 228          */
 229         flags &= ~FMODE_NONOTIFY;
 230         fdt = files_fdtable(ctx->files);
 231         /*
 232          * We need to check here again whether fd is within the fdt
 233          * max_fds range, because we might be seeing a different
 234          * files_fdtable() than iterate_fd(), assuming only RCU is
 235          * protecting the read. In reality, iterate_fd() holds
 236          * file_lock, which should ensure the fdt does not change while
 237          * the lock is taken, but we are not aware whether this is
 238          * guaranteed or not, so play safe.
 239          */
 240         if (fd < fdt->max_fds && lttng_close_on_exec(fd, fdt))
 241                 flags |= O_CLOEXEC;
 242         if (IS_ERR(s)) {
 243                 struct dentry *dentry = file->f_path.dentry;
 244
 245                 /* Make sure we give at least some info */
 246                 spin_lock(&dentry->d_lock);
 247                 trace_lttng_statedump_file_descriptor(ctx->session,
 248                         ctx->files, fd, dentry->d_name.name, flags,
 249                         file->f_mode);
 250                 spin_unlock(&dentry->d_lock);
 251                 goto end;
 252         }
 253         trace_lttng_statedump_file_descriptor(ctx->session,
 254                 ctx->files, fd, s, flags, file->f_mode);
 255 end:
 256         return 0;
 257 }
 258
 259 /* Called with task lock held. */
 260 static
 261 void lttng_enumerate_files(struct lttng_session *session,
 262                 struct files_struct *files,
 263                 char *tmp)
 264 {
 265         struct lttng_fd_ctx ctx = { .page = tmp, .session = session, .files = files, };
 266
 267         lttng_iterate_fd(files, 0, lttng_dump_one_fd, &ctx);
 268 }
 269
 270 #ifdef LTTNG_HAVE_STATEDUMP_CPU_TOPOLOGY
 271 static
 272 int lttng_enumerate_cpu_topology(struct lttng_session *session)
 273 {
 274         int cpu;
 275         const cpumask_t *cpumask = cpu_possible_mask;
 276
 277         for (cpu = cpumask_first(cpumask); cpu < nr_cpu_ids;
 278                         cpu = cpumask_next(cpu, cpumask)) {
 279                 trace_lttng_statedump_cpu_topology(session, &cpu_data(cpu));
 280         }
 281
 282         return 0;
 283 }
 284 #else
 285 static
 286 int lttng_enumerate_cpu_topology(struct lttng_session *session)
 287 {
 288         return 0;
 289 }
 290 #endif
 291
 292 #if 0
 293 /*
 294  * FIXME: we cannot take a mmap_sem while in a RCU read-side critical section
 295  * (scheduling in atomic). Normally, the tasklist lock protects this kind of
 296  * iteration, but it is not exported to modules.
 297  */
 298 static
 299 void lttng_enumerate_task_vm_maps(struct lttng_session *session,
 300                 struct task_struct *p)
 301 {
 302         struct mm_struct *mm;
 303         struct vm_area_struct *map;
 304         unsigned long ino;
 305
 306         /* get_task_mm does a task_lock... */
 307         mm = get_task_mm(p);
 308         if (!mm)
 309                 return;
 310
 311         map = mm->mmap;
 312         if (map) {
 313                 down_read(&mm->mmap_sem);
 314                 while (map) {
 315                         if (map->vm_file)
 316                                 ino = map->vm_file->lttng_f_dentry->d_inode->i_ino;
 317                         else
 318                                 ino = 0;
 319                         trace_lttng_statedump_vm_map(session, p, map, ino);
 320                         map = map->vm_next;
 321                 }
 322                 up_read(&mm->mmap_sem);
 323         }
 324         mmput(mm);
 325 }
 326
 327 static
 328 int lttng_enumerate_vm_maps(struct lttng_session *session)
 329 {
 330         struct task_struct *p;
 331
 332         rcu_read_lock();
 333         for_each_process(p)
 334                 lttng_enumerate_task_vm_maps(session, p);
 335         rcu_read_unlock();
 336         return 0;
 337 }
 338 #endif
 339
 340 #ifdef CONFIG_LTTNG_HAS_LIST_IRQ
 341
 342 static
 343 int lttng_list_interrupts(struct lttng_session *session)
 344 {
 345         unsigned int irq;
 346         unsigned long flags = 0;
 347         struct irq_desc *desc;
 348
 349 #define irq_to_desc     wrapper_irq_to_desc
 350         /* needs irq_desc */
 351         for_each_irq_desc(irq, desc) {
 352                 struct irqaction *action;
 353                 const char *irq_chip_name =
 354                         irq_desc_get_chip(desc)->name ? : "unnamed_irq_chip";
 355
 356                 local_irq_save(flags);
 357                 raw_spin_lock(&desc->lock);
 358                 for (action = desc->action; action; action = action->next) {
 359                         trace_lttng_statedump_interrupt(session,
 360                                 irq, irq_chip_name, action);
 361                 }
 362                 raw_spin_unlock(&desc->lock);
 363                 local_irq_restore(flags);
 364         }
 365         return 0;
 366 #undef irq_to_desc
 367 }
 368 #else
 369 static inline
 370 int lttng_list_interrupts(struct lttng_session *session)
 371 {
 372         return 0;
 373 }
 374 #endif
 375
 376 /*
 377  * Statedump the task's namespaces using the proc filesystem inode number as
 378  * the unique identifier. The user and pid ns are nested and will be dumped
 379  * recursively.
 380  *
 381  * Called with task lock held.
 382  */
 383 static
 384 void lttng_statedump_process_ns(struct lttng_session *session,
 385                 struct task_struct *p,
 386                 enum lttng_thread_type type,
 387                 enum lttng_execution_mode mode,
 388                 enum lttng_execution_submode submode,
 389                 enum lttng_process_status status)
 390 {
 391         struct nsproxy *proxy;
 392         struct pid_namespace *pid_ns;
 393         struct user_namespace *user_ns;
 394
 395         /*
 396          * The pid and user namespaces are special, they are nested and
 397          * accessed with specific functions instead of the nsproxy struct
 398          * like the other namespaces.
 399          */
 400         pid_ns = task_active_pid_ns(p);
 401         do {
 402                 trace_lttng_statedump_process_pid_ns(session, p, pid_ns);
 403                 pid_ns = pid_ns ? pid_ns->parent : NULL;
 404         } while (pid_ns);
 405
 406
 407         user_ns = task_cred_xxx(p, user_ns);
 408         do {
 409                 trace_lttng_statedump_process_user_ns(session, p, user_ns);
 410                 /*
 411                  * trace_lttng_statedump_process_user_ns() internally
 412                  * checks whether user_ns is NULL. While this does not
 413                  * appear to be a possible return value for
 414                  * task_cred_xxx(), err on the safe side and check
 415                  * for NULL here as well to be consistent with the
 416                  * paranoid behavior of
 417                  * trace_lttng_statedump_process_user_ns().
 418                  */
 419                 user_ns = user_ns ? user_ns->lttng_user_ns_parent : NULL;
 420         } while (user_ns);
 421
 422         /*
 423          * Back and forth on locking strategy within Linux upstream for nsproxy.
 424          * See Linux upstream commit 728dba3a39c66b3d8ac889ddbe38b5b1c264aec3
 425          * "namespaces: Use task_lock and not rcu to protect nsproxy"
 426          * for details.
 427          */
 428 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0) || \
 429                 LTTNG_UBUNTU_KERNEL_RANGE(3,13,11,36, 3,14,0,0) || \
 430                 LTTNG_UBUNTU_KERNEL_RANGE(3,16,1,11, 3,17,0,0) || \
 431                 LTTNG_RHEL_KERNEL_RANGE(3,10,0,229,13,0, 3,11,0,0,0,0))
 432         proxy = p->nsproxy;
 433 #else
 434         rcu_read_lock();
 435         proxy = task_nsproxy(p);
 436 #endif
 437         if (proxy) {
 438 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,6,0))
 439                 trace_lttng_statedump_process_cgroup_ns(session, p, proxy->cgroup_ns);
 440 #endif
 441                 trace_lttng_statedump_process_ipc_ns(session, p, proxy->ipc_ns);
 442 #ifndef LTTNG_MNT_NS_MISSING_HEADER
 443                 trace_lttng_statedump_process_mnt_ns(session, p, proxy->mnt_ns);
 444 #endif
 445                 trace_lttng_statedump_process_net_ns(session, p, proxy->net_ns);
 446                 trace_lttng_statedump_process_uts_ns(session, p, proxy->uts_ns);
 447         }
 448 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0) || \
 449                 LTTNG_UBUNTU_KERNEL_RANGE(3,13,11,36, 3,14,0,0) || \
 450                 LTTNG_UBUNTU_KERNEL_RANGE(3,16,1,11, 3,17,0,0) || \
 451                 LTTNG_RHEL_KERNEL_RANGE(3,10,0,229,13,0, 3,11,0,0,0,0))
 452         /* (nothing) */
 453 #else
 454         rcu_read_unlock();
 455 #endif
 456 }
 457
 458 static
 459 int lttng_enumerate_process_states(struct lttng_session *session)
 460 {
 461         struct task_struct *g, *p;
 462         char *tmp;
 463
 464         tmp = (char *) __get_free_page(GFP_KERNEL);
 465         if (!tmp)
 466                 return -ENOMEM;
 467
 468         rcu_read_lock();
 469         for_each_process(g) {
 470                 struct files_struct *prev_files = NULL;
 471
 472                 p = g;
 473                 do {
 474                         enum lttng_execution_mode mode =
 475                                 LTTNG_MODE_UNKNOWN;
 476                         enum lttng_execution_submode submode =
 477                                 LTTNG_UNKNOWN;
 478                         enum lttng_process_status status;
 479                         enum lttng_thread_type type;
 480                         struct files_struct *files;
 481
 482                         task_lock(p);
 483                         if (p->exit_state == EXIT_ZOMBIE)
 484                                 status = LTTNG_ZOMBIE;
 485                         else if (p->exit_state == EXIT_DEAD)
 486                                 status = LTTNG_DEAD;
 487                         else if (p->state == TASK_RUNNING) {
 488                                 /* Is this a forked child that has not run yet? */
 489                                 if (list_empty(&p->rt.run_list))
 490                                         status = LTTNG_WAIT_FORK;
 491                                 else
 492                                         /*
 493                                          * All tasks are considered as wait_cpu;
 494                                          * the viewer will sort out if the task
 495                                          * was really running at this time.
 496                                          */
 497                                         status = LTTNG_WAIT_CPU;
 498                         } else if (p->state &
 499                                 (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)) {
 500                                 /* Task is waiting for something to complete */
 501                                 status = LTTNG_WAIT;
 502                         } else
 503                                 status = LTTNG_UNNAMED;
 504                         submode = LTTNG_NONE;
 505
 506                         /*
 507                          * Verification of t->mm is to filter out kernel
 508                          * threads; Viewer will further filter out if a
 509                          * user-space thread was in syscall mode or not.
 510                          */
 511                         if (p->mm)
 512                                 type = LTTNG_USER_THREAD;
 513                         else
 514                                 type = LTTNG_KERNEL_THREAD;
 515                         files = p->files;
 516
 517                         trace_lttng_statedump_process_state(session,
 518                                 p, type, mode, submode, status, files);
 519                         lttng_statedump_process_ns(session,
 520                                 p, type, mode, submode, status);
 521                         /*
 522                          * As an optimisation for the common case, do not
 523                          * repeat information for the same files_struct in
 524                          * two consecutive threads. This is the common case
 525                          * for threads sharing the same fd table. RCU guarantees
 526                          * that the same files_struct pointer is not re-used
 527                          * throughout processes/threads iteration.
 528                          */
 529                         if (files && files != prev_files) {
 530                                 lttng_enumerate_files(session, files, tmp);
 531                                 prev_files = files;
 532                         }
 533                         task_unlock(p);
 534                 } while_each_thread(g, p);
 535         }
 536         rcu_read_unlock();
 537
 538         free_page((unsigned long) tmp);
 539
 540         return 0;
 541 }
 542
 543 static
 544 void lttng_statedump_work_func(struct work_struct *work)
 545 {
 546         if (atomic_dec_and_test(&kernel_threads_to_run))
 547                 /* If we are the last thread, wake up do_lttng_statedump */
 548                 wake_up(&statedump_wq);
 549 }
 550
 551 static
 552 int do_lttng_statedump(struct lttng_session *session)
 553 {
 554         int cpu, ret;
 555
 556         trace_lttng_statedump_start(session);
 557         ret = lttng_enumerate_process_states(session);
 558         if (ret)
 559                 return ret;
 560         /*
 561          * FIXME
 562          * ret = lttng_enumerate_vm_maps(session);
 563          * if (ret)
 564          *      return ret;
 565          */
 566         ret = lttng_list_interrupts(session);
 567         if (ret)
 568                 return ret;
 569         ret = lttng_enumerate_network_ip_interface(session);
 570         if (ret)
 571                 return ret;
 572         ret = lttng_enumerate_block_devices(session);
 573         switch (ret) {
 574         case 0:
 575                 break;
 576         case -ENOSYS:
 577                 printk(KERN_WARNING "LTTng: block device enumeration is not supported by kernel\n");
 578                 break;
 579         default:
 580                 return ret;
 581         }
 582         ret = lttng_enumerate_cpu_topology(session);
 583         if (ret)
 584                 return ret;
 585
 586         /* TODO lttng_dump_idt_table(session); */
 587         /* TODO lttng_dump_softirq_vec(session); */
 588         /* TODO lttng_list_modules(session); */
 589         /* TODO lttng_dump_swap_files(session); */
 590
 591         /*
 592          * Fire off a work queue on each CPU. Their sole purpose in life
 593          * is to guarantee that each CPU has been in a state where is was in
 594          * syscall mode (i.e. not in a trap, an IRQ or a soft IRQ).
 595          */
 596         get_online_cpus();
 597         atomic_set(&kernel_threads_to_run, num_online_cpus());
 598         for_each_online_cpu(cpu) {
 599                 INIT_DELAYED_WORK(&cpu_work[cpu], lttng_statedump_work_func);
 600                 schedule_delayed_work_on(cpu, &cpu_work[cpu], 0);
 601         }
 602         /* Wait for all threads to run */
 603         __wait_event(statedump_wq, (atomic_read(&kernel_threads_to_run) == 0));
 604         put_online_cpus();
 605         /* Our work is done */
 606         trace_lttng_statedump_end(session);
 607         return 0;
 608 }
 609
 610 /*
 611  * Called with session mutex held.
 612  */
 613 int lttng_statedump_start(struct lttng_session *session)
 614 {
 615         return do_lttng_statedump(session);
 616 }
 617 EXPORT_SYMBOL_GPL(lttng_statedump_start);
 618
 619 static
 620 int __init lttng_statedump_init(void)
 621 {
 622         /*
 623          * Allow module to load even if the fixup cannot be done. This
 624          * will allow seemless transition when the underlying issue fix
 625          * is merged into the Linux kernel, and when tracepoint.c
 626          * "tracepoint_module_notify" is turned into a static function.
 627          */
 628         (void) wrapper_lttng_fixup_sig(THIS_MODULE);
 629         return 0;
 630 }
 631
 632 module_init(lttng_statedump_init);
 633
 634 static
 635 void __exit lttng_statedump_exit(void)
 636 {
 637 }
 638
 639 module_exit(lttng_statedump_exit);
 640
 641 MODULE_LICENSE("GPL and additional rights");
 642 MODULE_AUTHOR("Jean-Hugues Deschenes");
 643 MODULE_DESCRIPTION("LTTng statedump provider");
 644 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
 645         __stringify(LTTNG_MODULES_MINOR_VERSION) "."
 646         __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
 647         LTTNG_MODULES_EXTRAVERSION);