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 #include <linux/fdtable.h>
  36
  37 #include <lttng-events.h>
  38 #include <lttng-tracer.h>
  39 #include <wrapper/namespace.h>
  40 #include <wrapper/irq.h>
  41 #include <wrapper/tracepoint.h>
  42 #include <wrapper/genhd.h>
  43 #include <wrapper/file.h>
  44
  45 #ifdef CONFIG_LTTNG_HAS_LIST_IRQ
  46 #include <linux/irq.h>
  47 #endif
  48
  49 /* Define the tracepoints, but do not build the probes */
  50 #define CREATE_TRACE_POINTS
  51 #define TRACE_INCLUDE_PATH instrumentation/events/lttng-module
  52 #define TRACE_INCLUDE_FILE lttng-statedump
  53 #define LTTNG_INSTRUMENTATION
  54 #include <instrumentation/events/lttng-module/lttng-statedump.h>
  55
  56 DEFINE_TRACE(lttng_statedump_block_device);
  57 DEFINE_TRACE(lttng_statedump_end);
  58 DEFINE_TRACE(lttng_statedump_interrupt);
  59 DEFINE_TRACE(lttng_statedump_file_descriptor);
  60 DEFINE_TRACE(lttng_statedump_start);
  61 DEFINE_TRACE(lttng_statedump_process_state);
  62 DEFINE_TRACE(lttng_statedump_process_pid_ns);
  63 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,6,0))
  64 DEFINE_TRACE(lttng_statedump_process_cgroup_ns);
  65 #endif
  66 DEFINE_TRACE(lttng_statedump_process_ipc_ns);
  67 #ifndef LTTNG_MNT_NS_MISSING_HEADER
  68 DEFINE_TRACE(lttng_statedump_process_mnt_ns);
  69 #endif
  70 DEFINE_TRACE(lttng_statedump_process_net_ns);
  71 DEFINE_TRACE(lttng_statedump_process_user_ns);
  72 DEFINE_TRACE(lttng_statedump_process_uts_ns);
  73 DEFINE_TRACE(lttng_statedump_network_interface);
  74 #ifdef LTTNG_HAVE_STATEDUMP_CPU_TOPOLOGY
  75 DEFINE_TRACE(lttng_statedump_cpu_topology);
  76 #endif
  77
  78 struct lttng_fd_ctx {
  79         char *page;
  80         struct lttng_session *session;
  81         struct files_struct *files;
  82 };
  83
  84 /*
  85  * Protected by the trace lock.
  86  */
  87 static struct delayed_work cpu_work[NR_CPUS];
  88 static DECLARE_WAIT_QUEUE_HEAD(statedump_wq);
  89 static atomic_t kernel_threads_to_run;
  90
  91 enum lttng_thread_type {
  92         LTTNG_USER_THREAD = 0,
  93         LTTNG_KERNEL_THREAD = 1,
  94 };
  95
  96 enum lttng_execution_mode {
  97         LTTNG_USER_MODE = 0,
  98         LTTNG_SYSCALL = 1,
  99         LTTNG_TRAP = 2,
 100         LTTNG_IRQ = 3,
 101         LTTNG_SOFTIRQ = 4,
 102         LTTNG_MODE_UNKNOWN = 5,
 103 };
 104
 105 enum lttng_execution_submode {
 106         LTTNG_NONE = 0,
 107         LTTNG_UNKNOWN = 1,
 108 };
 109
 110 enum lttng_process_status {
 111         LTTNG_UNNAMED = 0,
 112         LTTNG_WAIT_FORK = 1,
 113         LTTNG_WAIT_CPU = 2,
 114         LTTNG_EXIT = 3,
 115         LTTNG_ZOMBIE = 4,
 116         LTTNG_WAIT = 5,
 117         LTTNG_RUN = 6,
 118         LTTNG_DEAD = 7,
 119 };
 120
 121 static
 122 int lttng_enumerate_block_devices(struct lttng_session *session)
 123 {
 124         struct class *ptr_block_class;
 125         struct device_type *ptr_disk_type;
 126         struct class_dev_iter iter;
 127         struct device *dev;
 128
 129         ptr_block_class = wrapper_get_block_class();
 130         if (!ptr_block_class)
 131                 return -ENOSYS;
 132         ptr_disk_type = wrapper_get_disk_type();
 133         if (!ptr_disk_type) {
 134                 return -ENOSYS;
 135         }
 136         class_dev_iter_init(&iter, ptr_block_class, NULL, ptr_disk_type);
 137         while ((dev = class_dev_iter_next(&iter))) {
 138                 struct disk_part_iter piter;
 139                 struct gendisk *disk = dev_to_disk(dev);
 140                 struct hd_struct *part;
 141
 142                 /*
 143                  * Don't show empty devices or things that have been
 144                  * suppressed
 145                  */
 146                 if (get_capacity(disk) == 0 ||
 147                     (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
 148                         continue;
 149
 150                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 151                 while ((part = disk_part_iter_next(&piter))) {
 152                         char name_buf[BDEVNAME_SIZE];
 153                         char *p;
 154
 155                         p = wrapper_disk_name(disk, part->partno, name_buf);
 156                         if (!p) {
 157                                 disk_part_iter_exit(&piter);
 158                                 class_dev_iter_exit(&iter);
 159                                 return -ENOSYS;
 160                         }
 161                         trace_lttng_statedump_block_device(session,
 162                                         part_devt(part), name_buf);
 163                 }
 164                 disk_part_iter_exit(&piter);
 165         }
 166         class_dev_iter_exit(&iter);
 167         return 0;
 168 }
 169
 170 #ifdef CONFIG_INET
 171
 172 static
 173 void lttng_enumerate_device(struct lttng_session *session,
 174                 struct net_device *dev)
 175 {
 176         struct in_device *in_dev;
 177         struct in_ifaddr *ifa;
 178
 179         if (dev->flags & IFF_UP) {
 180                 in_dev = in_dev_get(dev);
 181                 if (in_dev) {
 182                         for (ifa = in_dev->ifa_list; ifa != NULL;
 183                              ifa = ifa->ifa_next) {
 184                                 trace_lttng_statedump_network_interface(
 185                                         session, dev, ifa);
 186                         }
 187                         in_dev_put(in_dev);
 188                 }
 189         } else {
 190                 trace_lttng_statedump_network_interface(
 191                         session, dev, NULL);
 192         }
 193 }
 194
 195 static
 196 int lttng_enumerate_network_ip_interface(struct lttng_session *session)
 197 {
 198         struct net_device *dev;
 199
 200         read_lock(&dev_base_lock);
 201         for_each_netdev(&init_net, dev)
 202                 lttng_enumerate_device(session, dev);
 203         read_unlock(&dev_base_lock);
 204
 205         return 0;
 206 }
 207 #else /* CONFIG_INET */
 208 static inline
 209 int lttng_enumerate_network_ip_interface(struct lttng_session *session)
 210 {
 211         return 0;
 212 }
 213 #endif /* CONFIG_INET */
 214
 215 static
 216 int lttng_dump_one_fd(const void *p, struct file *file, unsigned int fd)
 217 {
 218         const struct lttng_fd_ctx *ctx = p;
 219         const char *s = d_path(&file->f_path, ctx->page, PAGE_SIZE);
 220         unsigned int flags = file->f_flags;
 221         struct fdtable *fdt;
 222
 223         /*
 224          * We don't expose kernel internal flags, only userspace-visible
 225          * flags.
 226          */
 227         flags &= ~FMODE_NONOTIFY;
 228         fdt = files_fdtable(ctx->files);
 229         /*
 230          * We need to check here again whether fd is within the fdt
 231          * max_fds range, because we might be seeing a different
 232          * files_fdtable() than iterate_fd(), assuming only RCU is
 233          * protecting the read. In reality, iterate_fd() holds
 234          * file_lock, which should ensure the fdt does not change while
 235          * the lock is taken, but we are not aware whether this is
 236          * guaranteed or not, so play safe.
 237          */
 238         if (fd < fdt->max_fds && close_on_exec(fd, fdt))
 239                 flags |= O_CLOEXEC;
 240         if (IS_ERR(s)) {
 241                 struct dentry *dentry = file->f_path.dentry;
 242
 243                 /* Make sure we give at least some info */
 244                 spin_lock(&dentry->d_lock);
 245                 trace_lttng_statedump_file_descriptor(ctx->session,
 246                         ctx->files, fd, dentry->d_name.name, flags,
 247                         file->f_mode);
 248                 spin_unlock(&dentry->d_lock);
 249                 goto end;
 250         }
 251         trace_lttng_statedump_file_descriptor(ctx->session,
 252                 ctx->files, fd, s, flags, file->f_mode);
 253 end:
 254         return 0;
 255 }
 256
 257 /* Called with task lock held. */
 258 static
 259 void lttng_enumerate_files(struct lttng_session *session,
 260                 struct files_struct *files,
 261                 char *tmp)
 262 {
 263         struct lttng_fd_ctx ctx = { .page = tmp, .session = session, .files = files, };
 264
 265         iterate_fd(files, 0, lttng_dump_one_fd, &ctx);
 266 }
 267
 268 #ifdef LTTNG_HAVE_STATEDUMP_CPU_TOPOLOGY
 269 static
 270 int lttng_enumerate_cpu_topology(struct lttng_session *session)
 271 {
 272         int cpu;
 273         const cpumask_t *cpumask = cpu_possible_mask;
 274
 275         for (cpu = cpumask_first(cpumask); cpu < nr_cpu_ids;
 276                         cpu = cpumask_next(cpu, cpumask)) {
 277                 trace_lttng_statedump_cpu_topology(session, &cpu_data(cpu));
 278         }
 279
 280         return 0;
 281 }
 282 #else
 283 static
 284 int lttng_enumerate_cpu_topology(struct lttng_session *session)
 285 {
 286         return 0;
 287 }
 288 #endif
 289
 290 #if 0
 291 /*
 292  * FIXME: we cannot take a mmap_sem while in a RCU read-side critical section
 293  * (scheduling in atomic). Normally, the tasklist lock protects this kind of
 294  * iteration, but it is not exported to modules.
 295  */
 296 static
 297 void lttng_enumerate_task_vm_maps(struct lttng_session *session,
 298                 struct task_struct *p)
 299 {
 300         struct mm_struct *mm;
 301         struct vm_area_struct *map;
 302         unsigned long ino;
 303
 304         /* get_task_mm does a task_lock... */
 305         mm = get_task_mm(p);
 306         if (!mm)
 307                 return;
 308
 309         map = mm->mmap;
 310         if (map) {
 311                 down_read(&mm->mmap_sem);
 312                 while (map) {
 313                         if (map->vm_file)
 314                                 ino = map->vm_file->lttng_f_dentry->d_inode->i_ino;
 315                         else
 316                                 ino = 0;
 317                         trace_lttng_statedump_vm_map(session, p, map, ino);
 318                         map = map->vm_next;
 319                 }
 320                 up_read(&mm->mmap_sem);
 321         }
 322         mmput(mm);
 323 }
 324
 325 static
 326 int lttng_enumerate_vm_maps(struct lttng_session *session)
 327 {
 328         struct task_struct *p;
 329
 330         rcu_read_lock();
 331         for_each_process(p)
 332                 lttng_enumerate_task_vm_maps(session, p);
 333         rcu_read_unlock();
 334         return 0;
 335 }
 336 #endif
 337
 338 #ifdef CONFIG_LTTNG_HAS_LIST_IRQ
 339
 340 static
 341 int lttng_list_interrupts(struct lttng_session *session)
 342 {
 343         unsigned int irq;
 344         unsigned long flags = 0;
 345         struct irq_desc *desc;
 346
 347         /* needs irq_desc */
 348         for_each_irq_desc(irq, desc) {
 349                 struct irqaction *action;
 350                 const char *irq_chip_name =
 351                         irq_desc_get_chip(desc)->name ? : "unnamed_irq_chip";
 352
 353                 local_irq_save(flags);
 354                 raw_spin_lock(&desc->lock);
 355                 for (action = desc->action; action; action = action->next) {
 356                         trace_lttng_statedump_interrupt(session,
 357                                 irq, irq_chip_name, action);
 358                 }
 359                 raw_spin_unlock(&desc->lock);
 360                 local_irq_restore(flags);
 361         }
 362         return 0;
 363 }
 364 #else
 365 static inline
 366 int lttng_list_interrupts(struct lttng_session *session)
 367 {
 368         return 0;
 369 }
 370 #endif
 371
 372 /*
 373  * Statedump the task's namespaces using the proc filesystem inode number as
 374  * the unique identifier. The user and pid ns are nested and will be dumped
 375  * recursively.
 376  *
 377  * Called with task lock held.
 378  */
 379 static
 380 void lttng_statedump_process_ns(struct lttng_session *session,
 381                 struct task_struct *p,
 382                 enum lttng_thread_type type,
 383                 enum lttng_execution_mode mode,
 384                 enum lttng_execution_submode submode,
 385                 enum lttng_process_status status)
 386 {
 387         struct nsproxy *proxy;
 388         struct pid_namespace *pid_ns;
 389         struct user_namespace *user_ns;
 390
 391         /*
 392          * The pid and user namespaces are special, they are nested and
 393          * accessed with specific functions instead of the nsproxy struct
 394          * like the other namespaces.
 395          */
 396         pid_ns = task_active_pid_ns(p);
 397         do {
 398                 trace_lttng_statedump_process_pid_ns(session, p, pid_ns);
 399                 pid_ns = pid_ns ? pid_ns->parent : NULL;
 400         } while (pid_ns);
 401
 402
 403         user_ns = task_cred_xxx(p, user_ns);
 404         do {
 405                 trace_lttng_statedump_process_user_ns(session, p, user_ns);
 406                 /*
 407                  * trace_lttng_statedump_process_user_ns() internally
 408                  * checks whether user_ns is NULL. While this does not
 409                  * appear to be a possible return value for
 410                  * task_cred_xxx(), err on the safe side and check
 411                  * for NULL here as well to be consistent with the
 412                  * paranoid behavior of
 413                  * trace_lttng_statedump_process_user_ns().
 414                  */
 415                 user_ns = user_ns ? user_ns->lttng_user_ns_parent : NULL;
 416         } while (user_ns);
 417
 418         /*
 419          * Back and forth on locking strategy within Linux upstream for nsproxy.
 420          * See Linux upstream commit 728dba3a39c66b3d8ac889ddbe38b5b1c264aec3
 421          * "namespaces: Use task_lock and not rcu to protect nsproxy"
 422          * for details.
 423          */
 424 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0) || \
 425                 LTTNG_UBUNTU_KERNEL_RANGE(3,13,11,36, 3,14,0,0) || \
 426                 LTTNG_UBUNTU_KERNEL_RANGE(3,16,1,11, 3,17,0,0) || \
 427                 LTTNG_RHEL_KERNEL_RANGE(3,10,0,229,13,0, 3,11,0,0,0,0))
 428         proxy = p->nsproxy;
 429 #else
 430         rcu_read_lock();
 431         proxy = task_nsproxy(p);
 432 #endif
 433         if (proxy) {
 434 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,6,0))
 435                 trace_lttng_statedump_process_cgroup_ns(session, p, proxy->cgroup_ns);
 436 #endif
 437                 trace_lttng_statedump_process_ipc_ns(session, p, proxy->ipc_ns);
 438 #ifndef LTTNG_MNT_NS_MISSING_HEADER
 439                 trace_lttng_statedump_process_mnt_ns(session, p, proxy->mnt_ns);
 440 #endif
 441                 trace_lttng_statedump_process_net_ns(session, p, proxy->net_ns);
 442                 trace_lttng_statedump_process_uts_ns(session, p, proxy->uts_ns);
 443         }
 444 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0) || \
 445                 LTTNG_UBUNTU_KERNEL_RANGE(3,13,11,36, 3,14,0,0) || \
 446                 LTTNG_UBUNTU_KERNEL_RANGE(3,16,1,11, 3,17,0,0) || \
 447                 LTTNG_RHEL_KERNEL_RANGE(3,10,0,229,13,0, 3,11,0,0,0,0))
 448         /* (nothing) */
 449 #else
 450         rcu_read_unlock();
 451 #endif
 452 }
 453
 454 static
 455 int lttng_enumerate_process_states(struct lttng_session *session)
 456 {
 457         struct task_struct *g, *p;
 458         char *tmp;
 459
 460         tmp = (char *) __get_free_page(GFP_KERNEL);
 461         if (!tmp)
 462                 return -ENOMEM;
 463
 464         rcu_read_lock();
 465         for_each_process(g) {
 466                 struct files_struct *prev_files = NULL;
 467
 468                 p = g;
 469                 do {
 470                         enum lttng_execution_mode mode =
 471                                 LTTNG_MODE_UNKNOWN;
 472                         enum lttng_execution_submode submode =
 473                                 LTTNG_UNKNOWN;
 474                         enum lttng_process_status status;
 475                         enum lttng_thread_type type;
 476                         struct files_struct *files;
 477
 478                         task_lock(p);
 479                         if (p->exit_state == EXIT_ZOMBIE)
 480                                 status = LTTNG_ZOMBIE;
 481                         else if (p->exit_state == EXIT_DEAD)
 482                                 status = LTTNG_DEAD;
 483                         else if (p->state == TASK_RUNNING) {
 484                                 /* Is this a forked child that has not run yet? */
 485                                 if (list_empty(&p->rt.run_list))
 486                                         status = LTTNG_WAIT_FORK;
 487                                 else
 488                                         /*
 489                                          * All tasks are considered as wait_cpu;
 490                                          * the viewer will sort out if the task
 491                                          * was really running at this time.
 492                                          */
 493                                         status = LTTNG_WAIT_CPU;
 494                         } else if (p->state &
 495                                 (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)) {
 496                                 /* Task is waiting for something to complete */
 497                                 status = LTTNG_WAIT;
 498                         } else
 499                                 status = LTTNG_UNNAMED;
 500                         submode = LTTNG_NONE;
 501
 502                         /*
 503                          * Verification of t->mm is to filter out kernel
 504                          * threads; Viewer will further filter out if a
 505                          * user-space thread was in syscall mode or not.
 506                          */
 507                         if (p->mm)
 508                                 type = LTTNG_USER_THREAD;
 509                         else
 510                                 type = LTTNG_KERNEL_THREAD;
 511                         files = p->files;
 512
 513                         trace_lttng_statedump_process_state(session,
 514                                 p, type, mode, submode, status, files);
 515                         lttng_statedump_process_ns(session,
 516                                 p, type, mode, submode, status);
 517                         /*
 518                          * As an optimisation for the common case, do not
 519                          * repeat information for the same files_struct in
 520                          * two consecutive threads. This is the common case
 521                          * for threads sharing the same fd table. RCU guarantees
 522                          * that the same files_struct pointer is not re-used
 523                          * throughout processes/threads iteration.
 524                          */
 525                         if (files && files != prev_files) {
 526                                 lttng_enumerate_files(session, files, tmp);
 527                                 prev_files = files;
 528                         }
 529                         task_unlock(p);
 530                 } while_each_thread(g, p);
 531         }
 532         rcu_read_unlock();
 533
 534         free_page((unsigned long) tmp);
 535
 536         return 0;
 537 }
 538
 539 static
 540 void lttng_statedump_work_func(struct work_struct *work)
 541 {
 542         if (atomic_dec_and_test(&kernel_threads_to_run))
 543                 /* If we are the last thread, wake up do_lttng_statedump */
 544                 wake_up(&statedump_wq);
 545 }
 546
 547 static
 548 int do_lttng_statedump(struct lttng_session *session)
 549 {
 550         int cpu, ret;
 551
 552         trace_lttng_statedump_start(session);
 553         ret = lttng_enumerate_process_states(session);
 554         if (ret)
 555                 return ret;
 556         /*
 557          * FIXME
 558          * ret = lttng_enumerate_vm_maps(session);
 559          * if (ret)
 560          *      return ret;
 561          */
 562         ret = lttng_list_interrupts(session);
 563         if (ret)
 564                 return ret;
 565         ret = lttng_enumerate_network_ip_interface(session);
 566         if (ret)
 567                 return ret;
 568         ret = lttng_enumerate_block_devices(session);
 569         switch (ret) {
 570         case 0:
 571                 break;
 572         case -ENOSYS:
 573                 printk(KERN_WARNING "LTTng: block device enumeration is not supported by kernel\n");
 574                 break;
 575         default:
 576                 return ret;
 577         }
 578         ret = lttng_enumerate_cpu_topology(session);
 579         if (ret)
 580                 return ret;
 581
 582         /* TODO lttng_dump_idt_table(session); */
 583         /* TODO lttng_dump_softirq_vec(session); */
 584         /* TODO lttng_list_modules(session); */
 585         /* TODO lttng_dump_swap_files(session); */
 586
 587         /*
 588          * Fire off a work queue on each CPU. Their sole purpose in life
 589          * is to guarantee that each CPU has been in a state where is was in
 590          * syscall mode (i.e. not in a trap, an IRQ or a soft IRQ).
 591          */
 592         get_online_cpus();
 593         atomic_set(&kernel_threads_to_run, num_online_cpus());
 594         for_each_online_cpu(cpu) {
 595                 INIT_DELAYED_WORK(&cpu_work[cpu], lttng_statedump_work_func);
 596                 schedule_delayed_work_on(cpu, &cpu_work[cpu], 0);
 597         }
 598         /* Wait for all threads to run */
 599         __wait_event(statedump_wq, (atomic_read(&kernel_threads_to_run) == 0));
 600         put_online_cpus();
 601         /* Our work is done */
 602         trace_lttng_statedump_end(session);
 603         return 0;
 604 }
 605
 606 /*
 607  * Called with session mutex held.
 608  */
 609 int lttng_statedump_start(struct lttng_session *session)
 610 {
 611         return do_lttng_statedump(session);
 612 }
 613 EXPORT_SYMBOL_GPL(lttng_statedump_start);
 614
 615 static
 616 int __init lttng_statedump_init(void)
 617 {
 618         /*
 619          * Allow module to load even if the fixup cannot be done. This
 620          * will allow seemless transition when the underlying issue fix
 621          * is merged into the Linux kernel, and when tracepoint.c
 622          * "tracepoint_module_notify" is turned into a static function.
 623          */
 624         (void) wrapper_lttng_fixup_sig(THIS_MODULE);
 625         return 0;
 626 }
 627
 628 module_init(lttng_statedump_init);
 629
 630 static
 631 void __exit lttng_statedump_exit(void)
 632 {
 633 }
 634
 635 module_exit(lttng_statedump_exit);
 636
 637 MODULE_LICENSE("GPL and additional rights");
 638 MODULE_AUTHOR("Jean-Hugues Deschenes");
 639 MODULE_DESCRIPTION("LTTng statedump provider");
 640 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
 641         __stringify(LTTNG_MODULES_MINOR_VERSION) "."
 642         __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
 643         LTTNG_MODULES_EXTRAVERSION);