src/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/netdevice.h>
  27 #include <linux/inetdevice.h>
  28 #include <linux/mm.h>
  29 #include <linux/swap.h>
  30 #include <linux/wait.h>
  31 #include <linux/mutex.h>
  32 #include <linux/device.h>
  33
  34 #include <linux/blkdev.h>
  35
  36 #include <lttng/events.h>
  37 #include <lttng/tracer.h>
  38 #include <wrapper/cpu.h>
  39 #include <wrapper/irqdesc.h>
  40 #include <wrapper/fdtable.h>
  41 #include <wrapper/namespace.h>
  42 #include <wrapper/irq.h>
  43 #include <wrapper/tracepoint.h>
  44 #include <wrapper/blkdev.h>
  45 #include <wrapper/file.h>
  46 #include <wrapper/fdtable.h>
  47 #include <wrapper/sched.h>
  48
  49 #ifdef CONFIG_LTTNG_HAS_LIST_IRQ
  50 #include <linux/irq.h>
  51 #endif
  52
  53 /* Define the tracepoints, but do not build the probes */
  54 #define CREATE_TRACE_POINTS
  55 #define TRACE_INCLUDE_PATH instrumentation/events
  56 #define TRACE_INCLUDE_FILE lttng-statedump
  57 #define LTTNG_INSTRUMENTATION
  58 #include <instrumentation/events/lttng-statedump.h>
  59
  60 LTTNG_DEFINE_TRACE(lttng_statedump_block_device,
  61         TP_PROTO(struct lttng_kernel_session *session,
  62                 dev_t dev, const char *diskname),
  63         TP_ARGS(session, dev, diskname));
  64
  65 LTTNG_DEFINE_TRACE(lttng_statedump_end,
  66         TP_PROTO(struct lttng_kernel_session *session),
  67         TP_ARGS(session));
  68
  69 LTTNG_DEFINE_TRACE(lttng_statedump_interrupt,
  70         TP_PROTO(struct lttng_kernel_session *session,
  71                 unsigned int irq, const char *chip_name,
  72                 struct irqaction *action),
  73         TP_ARGS(session, irq, chip_name, action));
  74
  75 LTTNG_DEFINE_TRACE(lttng_statedump_file_descriptor,
  76         TP_PROTO(struct lttng_kernel_session *session,
  77                 struct files_struct *files,
  78                 int fd, const char *filename,
  79                 unsigned int flags, fmode_t fmode),
  80         TP_ARGS(session, files, fd, filename, flags, fmode));
  81
  82 LTTNG_DEFINE_TRACE(lttng_statedump_start,
  83         TP_PROTO(struct lttng_kernel_session *session),
  84         TP_ARGS(session));
  85
  86 LTTNG_DEFINE_TRACE(lttng_statedump_process_state,
  87         TP_PROTO(struct lttng_kernel_session *session,
  88                 struct task_struct *p,
  89                 int type, int mode, int submode, int status,
  90                 struct files_struct *files),
  91         TP_ARGS(session, p, type, mode, submode, status, files));
  92
  93 LTTNG_DEFINE_TRACE(lttng_statedump_process_pid_ns,
  94         TP_PROTO(struct lttng_kernel_session *session,
  95                 struct task_struct *p,
  96                 struct pid_namespace *pid_ns),
  97         TP_ARGS(session, p, pid_ns));
  98
  99 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,6,0))
 100 LTTNG_DEFINE_TRACE(lttng_statedump_process_cgroup_ns,
 101         TP_PROTO(struct lttng_kernel_session *session,
 102                 struct task_struct *p,
 103                 struct cgroup_namespace *cgroup_ns),
 104         TP_ARGS(session, p, cgroup_ns));
 105 #endif
 106
 107 LTTNG_DEFINE_TRACE(lttng_statedump_process_ipc_ns,
 108         TP_PROTO(struct lttng_kernel_session *session,
 109                 struct task_struct *p,
 110                 struct ipc_namespace *ipc_ns),
 111         TP_ARGS(session, p, ipc_ns));
 112
 113 #ifndef LTTNG_MNT_NS_MISSING_HEADER
 114 LTTNG_DEFINE_TRACE(lttng_statedump_process_mnt_ns,
 115         TP_PROTO(struct lttng_kernel_session *session,
 116                 struct task_struct *p,
 117                 struct mnt_namespace *mnt_ns),
 118         TP_ARGS(session, p, mnt_ns));
 119 #endif
 120
 121 LTTNG_DEFINE_TRACE(lttng_statedump_process_net_ns,
 122         TP_PROTO(struct lttng_kernel_session *session,
 123                 struct task_struct *p,
 124                 struct net *net_ns),
 125         TP_ARGS(session, p, net_ns));
 126
 127 LTTNG_DEFINE_TRACE(lttng_statedump_process_user_ns,
 128         TP_PROTO(struct lttng_kernel_session *session,
 129                 struct task_struct *p,
 130                 struct user_namespace *user_ns),
 131         TP_ARGS(session, p, user_ns));
 132
 133 LTTNG_DEFINE_TRACE(lttng_statedump_process_uts_ns,
 134         TP_PROTO(struct lttng_kernel_session *session,
 135                 struct task_struct *p,
 136                 struct uts_namespace *uts_ns),
 137         TP_ARGS(session, p, uts_ns));
 138
 139 LTTNG_DEFINE_TRACE(lttng_statedump_process_time_ns,
 140         TP_PROTO(struct lttng_kernel_session *session,
 141                 struct task_struct *p,
 142                 struct time_namespace *time_ns),
 143         TP_ARGS(session, p, time_ns));
 144
 145 LTTNG_DEFINE_TRACE(lttng_statedump_network_interface,
 146         TP_PROTO(struct lttng_kernel_session *session,
 147                 struct net_device *dev, struct in_ifaddr *ifa),
 148         TP_ARGS(session, dev, ifa));
 149
 150 #ifdef LTTNG_HAVE_STATEDUMP_CPU_TOPOLOGY
 151 LTTNG_DEFINE_TRACE(lttng_statedump_cpu_topology,
 152         TP_PROTO(struct lttng_kernel_session *session, struct cpuinfo_x86 *c),
 153         TP_ARGS(session, c));
 154 #endif
 155
 156 struct lttng_fd_ctx {
 157         char *page;
 158         struct lttng_kernel_session *session;
 159         struct files_struct *files;
 160 };
 161
 162 /*
 163  * Protected by the trace lock.
 164  */
 165 static struct delayed_work cpu_work[NR_CPUS];
 166 static DECLARE_WAIT_QUEUE_HEAD(statedump_wq);
 167 static atomic_t kernel_threads_to_run;
 168
 169 enum lttng_thread_type {
 170         LTTNG_USER_THREAD = 0,
 171         LTTNG_KERNEL_THREAD = 1,
 172 };
 173
 174 enum lttng_execution_mode {
 175         LTTNG_USER_MODE = 0,
 176         LTTNG_SYSCALL = 1,
 177         LTTNG_TRAP = 2,
 178         LTTNG_IRQ = 3,
 179         LTTNG_SOFTIRQ = 4,
 180         LTTNG_MODE_UNKNOWN = 5,
 181 };
 182
 183 enum lttng_execution_submode {
 184         LTTNG_NONE = 0,
 185         LTTNG_UNKNOWN = 1,
 186 };
 187
 188 enum lttng_process_status {
 189         LTTNG_UNNAMED = 0,
 190         LTTNG_WAIT_FORK = 1,
 191         LTTNG_WAIT_CPU = 2,
 192         LTTNG_EXIT = 3,
 193         LTTNG_ZOMBIE = 4,
 194         LTTNG_WAIT = 5,
 195         LTTNG_RUN = 6,
 196         LTTNG_DEAD = 7,
 197 };
 198
 199
 200 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(6,0,0))
 201
 202 #define LTTNG_PART_STRUCT_TYPE struct block_device
 203
 204 static
 205 int lttng_get_part_name(struct gendisk *disk, struct block_device *part, char *name_buf)
 206 {
 207         int ret;
 208
 209         ret = snprintf(name_buf, BDEVNAME_SIZE, "%pg", part);
 210         if (ret < 0 || ret >= BDEVNAME_SIZE)
 211                 return -ENOSYS;
 212
 213         return 0;
 214 }
 215
 216 static
 217 dev_t lttng_get_part_devt(struct block_device *part)
 218 {
 219         return part->bd_dev;
 220 }
 221
 222 #elif (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,11,0))
 223
 224 #define LTTNG_PART_STRUCT_TYPE struct block_device
 225
 226 static
 227 int lttng_get_part_name(struct gendisk *disk, struct block_device *part, char *name_buf)
 228 {
 229         const char *p;
 230
 231         p = bdevname(part, name_buf);
 232         if (!p)
 233                 return -ENOSYS;
 234
 235         return 0;
 236 }
 237
 238 static
 239 dev_t lttng_get_part_devt(struct block_device *part)
 240 {
 241         return part->bd_dev;
 242 }
 243
 244 #else
 245
 246 #define LTTNG_PART_STRUCT_TYPE struct hd_struct
 247
 248 static
 249 int lttng_get_part_name(struct gendisk *disk, struct hd_struct *part, char *name_buf)
 250 {
 251         const char *p;
 252         struct block_device bdev;
 253
 254         /*
 255          * Create a partial 'struct blockdevice' to use
 256          * 'bdevname()' which is a simple wrapper over
 257          * 'disk_name()' but has the honor to be EXPORT_SYMBOL.
 258          */
 259         bdev.bd_disk = disk;
 260         bdev.bd_part = part;
 261
 262         p = bdevname(&bdev, name_buf);
 263         if (!p)
 264                 return -ENOSYS;
 265
 266         return 0;
 267 }
 268
 269 static
 270 dev_t lttng_get_part_devt(struct hd_struct *part)
 271 {
 272         return part_devt(part);
 273 }
 274 #endif
 275
 276 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,12,0))
 277 static
 278 int lttng_statedump_each_block_device(struct lttng_kernel_session *session, struct gendisk *disk)
 279 {
 280         struct block_device *part;
 281         unsigned long idx;
 282         int ret = 0;
 283
 284         /* Include partition 0 */
 285         idx = 0;
 286
 287         rcu_read_lock();
 288         xa_for_each(&disk->part_tbl, idx, part) {
 289                 char name_buf[BDEVNAME_SIZE];
 290
 291                 /* Exclude non-partitions bdev and empty partitions. */
 292                 if (bdev_is_partition(part) && !bdev_nr_sectors(part))
 293                         continue;
 294
 295                 if (lttng_get_part_name(disk, part, name_buf) == -ENOSYS) {
 296                         ret = -ENOSYS;
 297                         goto end;
 298                 }
 299                 trace_lttng_statedump_block_device(session, lttng_get_part_devt(part),
 300                                 name_buf);
 301         }
 302 end:
 303         rcu_read_unlock();
 304         return ret;
 305 }
 306 #else
 307 static
 308 int lttng_statedump_each_block_device(struct lttng_kernel_session *session, struct gendisk *disk)
 309 {
 310         struct disk_part_iter piter;
 311         LTTNG_PART_STRUCT_TYPE *part;
 312
 313         disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 314
 315         while ((part = disk_part_iter_next(&piter))) {
 316                 char name_buf[BDEVNAME_SIZE];
 317
 318                 if (lttng_get_part_name(disk, part, name_buf) == -ENOSYS) {
 319                         disk_part_iter_exit(&piter);
 320                         return -ENOSYS;
 321                 }
 322                 trace_lttng_statedump_block_device(session, lttng_get_part_devt(part),
 323                                 name_buf);
 324         }
 325         disk_part_iter_exit(&piter);
 326
 327         return 0;
 328 }
 329 #endif
 330
 331 static
 332 int lttng_enumerate_block_devices(struct lttng_kernel_session *session)
 333 {
 334         struct class *ptr_block_class;
 335         struct device_type *ptr_disk_type;
 336         struct class_dev_iter iter;
 337         struct device *dev;
 338         int ret = 0;
 339
 340         ptr_block_class = wrapper_get_block_class();
 341         if (!ptr_block_class) {
 342                 ret = -ENOSYS;
 343                 goto end;
 344         }
 345         ptr_disk_type = wrapper_get_disk_type();
 346         if (!ptr_disk_type) {
 347                 ret = -ENOSYS;
 348                 goto end;
 349         }
 350         class_dev_iter_init(&iter, ptr_block_class, NULL, ptr_disk_type);
 351         while ((dev = class_dev_iter_next(&iter))) {
 352                 struct gendisk *disk = dev_to_disk(dev);
 353
 354                 /*
 355                  * Don't show empty devices or things that have been
 356                  * suppressed
 357                  */
 358                 if (get_capacity(disk) == 0 ||
 359                     (disk->flags & LTTNG_GENHD_FL_HIDDEN))
 360                         continue;
 361
 362                 ret = lttng_statedump_each_block_device(session, disk);
 363         }
 364         class_dev_iter_exit(&iter);
 365 end:
 366         return ret;
 367 }
 368
 369 #ifdef CONFIG_INET
 370
 371 static
 372 void lttng_enumerate_device(struct lttng_kernel_session *session,
 373                 struct net_device *dev)
 374 {
 375         struct in_device *in_dev;
 376         struct in_ifaddr *ifa;
 377
 378         if (dev->flags & IFF_UP) {
 379                 in_dev = in_dev_get(dev);
 380                 if (in_dev) {
 381                         for (ifa = in_dev->ifa_list; ifa != NULL;
 382                              ifa = ifa->ifa_next) {
 383                                 trace_lttng_statedump_network_interface(
 384                                         session, dev, ifa);
 385                         }
 386                         in_dev_put(in_dev);
 387                 }
 388         } else {
 389                 trace_lttng_statedump_network_interface(
 390                         session, dev, NULL);
 391         }
 392 }
 393
 394 static
 395 int lttng_enumerate_network_ip_interface(struct lttng_kernel_session *session)
 396 {
 397         struct net_device *dev;
 398
 399         read_lock(&dev_base_lock);
 400         for_each_netdev(&init_net, dev)
 401                 lttng_enumerate_device(session, dev);
 402         read_unlock(&dev_base_lock);
 403
 404         return 0;
 405 }
 406 #else /* CONFIG_INET */
 407 static inline
 408 int lttng_enumerate_network_ip_interface(struct lttng_kernel_session *session)
 409 {
 410         return 0;
 411 }
 412 #endif /* CONFIG_INET */
 413
 414 static
 415 int lttng_dump_one_fd(const void *p, struct file *file, unsigned int fd)
 416 {
 417         const struct lttng_fd_ctx *ctx = p;
 418         const char *s = d_path(&file->f_path, ctx->page, PAGE_SIZE);
 419         unsigned int flags = file->f_flags;
 420         struct fdtable *fdt;
 421
 422         /*
 423          * We don't expose kernel internal flags, only userspace-visible
 424          * flags.
 425          */
 426         flags &= ~FMODE_NONOTIFY;
 427         fdt = files_fdtable(ctx->files);
 428         /*
 429          * We need to check here again whether fd is within the fdt
 430          * max_fds range, because we might be seeing a different
 431          * files_fdtable() than iterate_fd(), assuming only RCU is
 432          * protecting the read. In reality, iterate_fd() holds
 433          * file_lock, which should ensure the fdt does not change while
 434          * the lock is taken, but we are not aware whether this is
 435          * guaranteed or not, so play safe.
 436          */
 437         if (fd < fdt->max_fds && lttng_close_on_exec(fd, fdt))
 438                 flags |= O_CLOEXEC;
 439         if (IS_ERR(s)) {
 440                 struct dentry *dentry = file->f_path.dentry;
 441
 442                 /* Make sure we give at least some info */
 443                 spin_lock(&dentry->d_lock);
 444                 trace_lttng_statedump_file_descriptor(ctx->session,
 445                         ctx->files, fd, dentry->d_name.name, flags,
 446                         file->f_mode);
 447                 spin_unlock(&dentry->d_lock);
 448                 goto end;
 449         }
 450         trace_lttng_statedump_file_descriptor(ctx->session,
 451                 ctx->files, fd, s, flags, file->f_mode);
 452 end:
 453         return 0;
 454 }
 455
 456 /* Called with task lock held. */
 457 static
 458 void lttng_enumerate_files(struct lttng_kernel_session *session,
 459                 struct files_struct *files,
 460                 char *tmp)
 461 {
 462         struct lttng_fd_ctx ctx = { .page = tmp, .session = session, .files = files, };
 463
 464         lttng_iterate_fd(files, 0, lttng_dump_one_fd, &ctx);
 465 }
 466
 467 #ifdef LTTNG_HAVE_STATEDUMP_CPU_TOPOLOGY
 468 static
 469 int lttng_enumerate_cpu_topology(struct lttng_kernel_session *session)
 470 {
 471         int cpu;
 472         const cpumask_t *cpumask = cpu_possible_mask;
 473
 474         for (cpu = cpumask_first(cpumask); cpu < nr_cpu_ids;
 475                         cpu = cpumask_next(cpu, cpumask)) {
 476                 trace_lttng_statedump_cpu_topology(session, &cpu_data(cpu));
 477         }
 478
 479         return 0;
 480 }
 481 #else
 482 static
 483 int lttng_enumerate_cpu_topology(struct lttng_kernel_session *session)
 484 {
 485         return 0;
 486 }
 487 #endif
 488
 489 #if 0
 490 /*
 491  * FIXME: we cannot take a mmap_sem while in a RCU read-side critical section
 492  * (scheduling in atomic). Normally, the tasklist lock protects this kind of
 493  * iteration, but it is not exported to modules.
 494  */
 495 static
 496 void lttng_enumerate_task_vm_maps(struct lttng_kernel_session *session,
 497                 struct task_struct *p)
 498 {
 499         struct mm_struct *mm;
 500         struct vm_area_struct *map;
 501         unsigned long ino;
 502
 503         /* get_task_mm does a task_lock... */
 504         mm = get_task_mm(p);
 505         if (!mm)
 506                 return;
 507
 508         map = mm->mmap;
 509         if (map) {
 510                 down_read(&mm->mmap_sem);
 511                 while (map) {
 512                         if (map->vm_file)
 513                                 ino = map->vm_file->lttng_f_dentry->d_inode->i_ino;
 514                         else
 515                                 ino = 0;
 516                         trace_lttng_statedump_vm_map(session, p, map, ino);
 517                         map = map->vm_next;
 518                 }
 519                 up_read(&mm->mmap_sem);
 520         }
 521         mmput(mm);
 522 }
 523
 524 static
 525 int lttng_enumerate_vm_maps(struct lttng_kernel_session *session)
 526 {
 527         struct task_struct *p;
 528
 529         rcu_read_lock();
 530         for_each_process(p)
 531                 lttng_enumerate_task_vm_maps(session, p);
 532         rcu_read_unlock();
 533         return 0;
 534 }
 535 #endif
 536
 537 #ifdef CONFIG_LTTNG_HAS_LIST_IRQ
 538
 539 static
 540 int lttng_list_interrupts(struct lttng_kernel_session *session)
 541 {
 542         unsigned int irq;
 543         unsigned long flags = 0;
 544         struct irq_desc *desc;
 545
 546 #define irq_to_desc     wrapper_irq_to_desc
 547         /* needs irq_desc */
 548         for_each_irq_desc(irq, desc) {
 549                 struct irqaction *action;
 550                 const char *irq_chip_name =
 551                         irq_desc_get_chip(desc)->name ? : "unnamed_irq_chip";
 552
 553                 local_irq_save(flags);
 554                 raw_spin_lock(&desc->lock);
 555                 for (action = desc->action; action; action = action->next) {
 556                         trace_lttng_statedump_interrupt(session,
 557                                 irq, irq_chip_name, action);
 558                 }
 559                 raw_spin_unlock(&desc->lock);
 560                 local_irq_restore(flags);
 561         }
 562         return 0;
 563 #undef irq_to_desc
 564 }
 565 #else
 566 static inline
 567 int lttng_list_interrupts(struct lttng_kernel_session *session)
 568 {
 569         return 0;
 570 }
 571 #endif
 572
 573 /*
 574  * Statedump the task's namespaces using the proc filesystem inode number as
 575  * the unique identifier. The user and pid ns are nested and will be dumped
 576  * recursively.
 577  *
 578  * Called with task lock held.
 579  */
 580 static
 581 void lttng_statedump_process_ns(struct lttng_kernel_session *session,
 582                 struct task_struct *p,
 583                 enum lttng_thread_type type,
 584                 enum lttng_execution_mode mode,
 585                 enum lttng_execution_submode submode,
 586                 enum lttng_process_status status)
 587 {
 588         struct nsproxy *proxy;
 589         struct pid_namespace *pid_ns;
 590         struct user_namespace *user_ns;
 591
 592         /*
 593          * The pid and user namespaces are special, they are nested and
 594          * accessed with specific functions instead of the nsproxy struct
 595          * like the other namespaces.
 596          */
 597         pid_ns = task_active_pid_ns(p);
 598         do {
 599                 trace_lttng_statedump_process_pid_ns(session, p, pid_ns);
 600                 pid_ns = pid_ns ? pid_ns->parent : NULL;
 601         } while (pid_ns);
 602
 603
 604         user_ns = task_cred_xxx(p, user_ns);
 605         do {
 606                 trace_lttng_statedump_process_user_ns(session, p, user_ns);
 607                 /*
 608                  * trace_lttng_statedump_process_user_ns() internally
 609                  * checks whether user_ns is NULL. While this does not
 610                  * appear to be a possible return value for
 611                  * task_cred_xxx(), err on the safe side and check
 612                  * for NULL here as well to be consistent with the
 613                  * paranoid behavior of
 614                  * trace_lttng_statedump_process_user_ns().
 615                  */
 616                 user_ns = user_ns ? user_ns->lttng_user_ns_parent : NULL;
 617         } while (user_ns);
 618
 619         /*
 620          * Back and forth on locking strategy within Linux upstream for nsproxy.
 621          * See Linux upstream commit 728dba3a39c66b3d8ac889ddbe38b5b1c264aec3
 622          * "namespaces: Use task_lock and not rcu to protect nsproxy"
 623          * for details.
 624          */
 625 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,17,0) || \
 626                 LTTNG_UBUNTU_KERNEL_RANGE(3,13,11,36, 3,14,0,0) || \
 627                 LTTNG_UBUNTU_KERNEL_RANGE(3,16,1,11, 3,17,0,0) || \
 628                 LTTNG_RHEL_KERNEL_RANGE(3,10,0,229,13,0, 3,11,0,0,0,0))
 629         proxy = p->nsproxy;
 630 #else
 631         rcu_read_lock();
 632         proxy = task_nsproxy(p);
 633 #endif
 634         if (proxy) {
 635 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,6,0))
 636                 trace_lttng_statedump_process_cgroup_ns(session, p, proxy->cgroup_ns);
 637 #endif
 638                 trace_lttng_statedump_process_ipc_ns(session, p, proxy->ipc_ns);
 639 #ifndef LTTNG_MNT_NS_MISSING_HEADER
 640                 trace_lttng_statedump_process_mnt_ns(session, p, proxy->mnt_ns);
 641 #endif
 642                 trace_lttng_statedump_process_net_ns(session, p, proxy->net_ns);
 643                 trace_lttng_statedump_process_uts_ns(session, p, proxy->uts_ns);
 644 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0) || \
 645         LTTNG_RHEL_KERNEL_RANGE(4,18,0,305,0,0, 4,19,0,0,0,0))
 646                 trace_lttng_statedump_process_time_ns(session, p, proxy->time_ns);
 647 #endif
 648         }
 649 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,17,0) || \
 650                 LTTNG_UBUNTU_KERNEL_RANGE(3,13,11,36, 3,14,0,0) || \
 651                 LTTNG_UBUNTU_KERNEL_RANGE(3,16,1,11, 3,17,0,0) || \
 652                 LTTNG_RHEL_KERNEL_RANGE(3,10,0,229,13,0, 3,11,0,0,0,0))
 653         /* (nothing) */
 654 #else
 655         rcu_read_unlock();
 656 #endif
 657 }
 658
 659 static
 660 int lttng_enumerate_process_states(struct lttng_kernel_session *session)
 661 {
 662         struct task_struct *g, *p;
 663         char *tmp;
 664
 665         tmp = (char *) __get_free_page(GFP_KERNEL);
 666         if (!tmp)
 667                 return -ENOMEM;
 668
 669         rcu_read_lock();
 670         for_each_process(g) {
 671                 struct files_struct *prev_files = NULL;
 672
 673                 p = g;
 674                 do {
 675                         enum lttng_execution_mode mode =
 676                                 LTTNG_MODE_UNKNOWN;
 677                         enum lttng_execution_submode submode =
 678                                 LTTNG_UNKNOWN;
 679                         enum lttng_process_status status;
 680                         enum lttng_thread_type type;
 681                         struct files_struct *files;
 682
 683                         task_lock(p);
 684                         if (p->exit_state == EXIT_ZOMBIE)
 685                                 status = LTTNG_ZOMBIE;
 686                         else if (p->exit_state == EXIT_DEAD)
 687                                 status = LTTNG_DEAD;
 688                         else if (lttng_task_is_running(p)) {
 689                                 /* Is this a forked child that has not run yet? */
 690                                 if (list_empty(&p->rt.run_list))
 691                                         status = LTTNG_WAIT_FORK;
 692                                 else
 693                                         /*
 694                                          * All tasks are considered as wait_cpu;
 695                                          * the viewer will sort out if the task
 696                                          * was really running at this time.
 697                                          */
 698                                         status = LTTNG_WAIT_CPU;
 699                         } else if (lttng_get_task_state(p) &
 700                                 (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)) {
 701                                 /* Task is waiting for something to complete */
 702                                 status = LTTNG_WAIT;
 703                         } else
 704                                 status = LTTNG_UNNAMED;
 705                         submode = LTTNG_NONE;
 706
 707                         /*
 708                          * Verification of t->mm is to filter out kernel
 709                          * threads; Viewer will further filter out if a
 710                          * user-space thread was in syscall mode or not.
 711                          */
 712                         if (p->mm)
 713                                 type = LTTNG_USER_THREAD;
 714                         else
 715                                 type = LTTNG_KERNEL_THREAD;
 716                         files = p->files;
 717
 718                         trace_lttng_statedump_process_state(session,
 719                                 p, type, mode, submode, status, files);
 720                         lttng_statedump_process_ns(session,
 721                                 p, type, mode, submode, status);
 722                         /*
 723                          * As an optimisation for the common case, do not
 724                          * repeat information for the same files_struct in
 725                          * two consecutive threads. This is the common case
 726                          * for threads sharing the same fd table. RCU guarantees
 727                          * that the same files_struct pointer is not re-used
 728                          * throughout processes/threads iteration.
 729                          */
 730                         if (files && files != prev_files) {
 731                                 lttng_enumerate_files(session, files, tmp);
 732                                 prev_files = files;
 733                         }
 734                         task_unlock(p);
 735                 } while_each_thread(g, p);
 736         }
 737         rcu_read_unlock();
 738
 739         free_page((unsigned long) tmp);
 740
 741         return 0;
 742 }
 743
 744 static
 745 void lttng_statedump_work_func(struct work_struct *work)
 746 {
 747         if (atomic_dec_and_test(&kernel_threads_to_run))
 748                 /* If we are the last thread, wake up do_lttng_statedump */
 749                 wake_up(&statedump_wq);
 750 }
 751
 752 static
 753 int do_lttng_statedump(struct lttng_kernel_session *session)
 754 {
 755         int cpu, ret;
 756
 757         trace_lttng_statedump_start(session);
 758         ret = lttng_enumerate_process_states(session);
 759         if (ret)
 760                 return ret;
 761         /*
 762          * FIXME
 763          * ret = lttng_enumerate_vm_maps(session);
 764          * if (ret)
 765          *      return ret;
 766          */
 767         ret = lttng_list_interrupts(session);
 768         if (ret)
 769                 return ret;
 770         ret = lttng_enumerate_network_ip_interface(session);
 771         if (ret)
 772                 return ret;
 773         ret = lttng_enumerate_block_devices(session);
 774         switch (ret) {
 775         case 0:
 776                 break;
 777         case -ENOSYS:
 778                 printk(KERN_WARNING "LTTng: block device enumeration is not supported by kernel\n");
 779                 break;
 780         default:
 781                 return ret;
 782         }
 783         ret = lttng_enumerate_cpu_topology(session);
 784         if (ret)
 785                 return ret;
 786
 787         /* TODO lttng_dump_idt_table(session); */
 788         /* TODO lttng_dump_softirq_vec(session); */
 789         /* TODO lttng_list_modules(session); */
 790         /* TODO lttng_dump_swap_files(session); */
 791
 792         /*
 793          * Fire off a work queue on each CPU. Their sole purpose in life
 794          * is to guarantee that each CPU has been in a state where is was in
 795          * syscall mode (i.e. not in a trap, an IRQ or a soft IRQ).
 796          */
 797         lttng_cpus_read_lock();
 798         atomic_set(&kernel_threads_to_run, num_online_cpus());
 799         for_each_online_cpu(cpu) {
 800                 INIT_DELAYED_WORK(&cpu_work[cpu], lttng_statedump_work_func);
 801                 schedule_delayed_work_on(cpu, &cpu_work[cpu], 0);
 802         }
 803         /* Wait for all threads to run */
 804         __wait_event(statedump_wq, (atomic_read(&kernel_threads_to_run) == 0));
 805         lttng_cpus_read_unlock();
 806         /* Our work is done */
 807         trace_lttng_statedump_end(session);
 808         return 0;
 809 }
 810
 811 /*
 812  * Called with session mutex held.
 813  */
 814 int lttng_statedump_start(struct lttng_kernel_session *session)
 815 {
 816         return do_lttng_statedump(session);
 817 }
 818 EXPORT_SYMBOL_GPL(lttng_statedump_start);
 819
 820 static
 821 int __init lttng_statedump_init(void)
 822 {
 823         /*
 824          * Allow module to load even if the fixup cannot be done. This
 825          * will allow seemless transition when the underlying issue fix
 826          * is merged into the Linux kernel, and when tracepoint.c
 827          * "tracepoint_module_notify" is turned into a static function.
 828          */
 829         (void) wrapper_lttng_fixup_sig(THIS_MODULE);
 830         return 0;
 831 }
 832
 833 module_init(lttng_statedump_init);
 834
 835 static
 836 void __exit lttng_statedump_exit(void)
 837 {
 838 }
 839
 840 module_exit(lttng_statedump_exit);
 841
 842 MODULE_LICENSE("GPL and additional rights");
 843 MODULE_AUTHOR("Jean-Hugues Deschenes");
 844 MODULE_DESCRIPTION("LTTng statedump provider");
 845 MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
 846         __stringify(LTTNG_MODULES_MINOR_VERSION) "."
 847         __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
 848         LTTNG_MODULES_EXTRAVERSION);