src/lttng-syscalls.c

   1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
   2  *
   3  * lttng-syscalls.c
   4  *
   5  * LTTng syscall probes.
   6  *
   7  * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/slab.h>
  12 #include <linux/compat.h>
  13 #include <linux/err.h>
  14 #include <linux/bitmap.h>
  15 #include <linux/in.h>
  16 #include <linux/in6.h>
  17 #include <linux/seq_file.h>
  18 #include <linux/stringify.h>
  19 #include <linux/file.h>
  20 #include <linux/anon_inodes.h>
  21 #include <linux/fcntl.h>
  22 #include <linux/mman.h>
  23 #include <asm/ptrace.h>
  24 #include <asm/syscall.h>
  25
  26 #include <lttng/bitfield.h>
  27 #include <wrapper/tracepoint.h>
  28 #include <wrapper/file.h>
  29 #include <wrapper/rcu.h>
  30 #include <wrapper/syscall.h>
  31 #include <lttng/events.h>
  32 #include <lttng/events-internal.h>
  33 #include <lttng/utils.h>
  34
  35 #include "lttng-syscalls.h"
  36
  37 #ifndef CONFIG_COMPAT
  38 # ifndef is_compat_task
  39 #  define is_compat_task()      (0)
  40 # endif
  41 #endif
  42
  43 /* in_compat_syscall appears in kernel 4.6. */
  44 #ifndef in_compat_syscall
  45  #define in_compat_syscall()    is_compat_task()
  46 #endif
  47
  48 enum sc_type {
  49         SC_TYPE_ENTRY,
  50         SC_TYPE_EXIT,
  51         SC_TYPE_COMPAT_ENTRY,
  52         SC_TYPE_COMPAT_EXIT,
  53 };
  54
  55 #define SYSCALL_ENTRY_TOK               syscall_entry_
  56 #define COMPAT_SYSCALL_ENTRY_TOK        compat_syscall_entry_
  57 #define SYSCALL_EXIT_TOK                syscall_exit_
  58 #define COMPAT_SYSCALL_EXIT_TOK         compat_syscall_exit_
  59
  60 #define SYSCALL_ENTRY_STR               __stringify(SYSCALL_ENTRY_TOK)
  61 #define COMPAT_SYSCALL_ENTRY_STR        __stringify(COMPAT_SYSCALL_ENTRY_TOK)
  62 #define SYSCALL_EXIT_STR                __stringify(SYSCALL_EXIT_TOK)
  63 #define COMPAT_SYSCALL_EXIT_STR         __stringify(COMPAT_SYSCALL_EXIT_TOK)
  64
  65 void syscall_entry_event_probe(void *__data, struct pt_regs *regs, long id);
  66 void syscall_exit_event_probe(void *__data, struct pt_regs *regs, long ret);
  67
  68 /*
  69  * Forward declarations for old kernels.
  70  */
  71 struct mmsghdr;
  72 struct rlimit64;
  73 struct oldold_utsname;
  74 struct old_utsname;
  75 struct sel_arg_struct;
  76 struct mmap_arg_struct;
  77 struct file_handle;
  78 struct user_msghdr;
  79
  80 /*
  81  * Forward declaration for kernels >= 5.6
  82  */
  83 struct timex;
  84 struct timeval;
  85 struct itimerval;
  86 struct itimerspec;
  87
  88 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0))
  89 typedef __kernel_old_time_t time_t;
  90 #endif
  91
  92 #ifdef IA32_NR_syscalls
  93 #define NR_compat_syscalls IA32_NR_syscalls
  94 #else
  95 #define NR_compat_syscalls NR_syscalls
  96 #endif
  97
  98 /*
  99  * Create LTTng tracepoint probes.
 100  */
 101 #define LTTNG_PACKAGE_BUILD
 102 #define CREATE_TRACE_POINTS
 103 #define TP_MODULE_NOINIT
 104 #define TRACE_INCLUDE_PATH instrumentation/syscalls/headers
 105
 106 #define PARAMS(args...) args
 107
 108 /* Handle unknown syscalls */
 109 #undef TRACE_SYSTEM
 110 #define TRACE_SYSTEM syscalls_unknown
 111 #include <instrumentation/syscalls/headers/syscalls_unknown.h>
 112 #undef TRACE_SYSTEM
 113
 114 #undef TP_PROBE_CB
 115
 116 extern const struct trace_syscall_table sc_table;
 117 extern const struct trace_syscall_table compat_sc_table;
 118
 119 /* Event syscall exit table */
 120 extern const struct trace_syscall_table sc_exit_table;
 121 extern const struct trace_syscall_table compat_sc_exit_table;
 122
 123
 124 #undef SC_EXIT
 125
 126 #undef CREATE_SYSCALL_TABLE
 127
 128 struct lttng_syscall_filter {
 129         DECLARE_BITMAP(sc_entry, NR_syscalls);
 130         DECLARE_BITMAP(sc_exit, NR_syscalls);
 131         DECLARE_BITMAP(sc_compat_entry, NR_compat_syscalls);
 132         DECLARE_BITMAP(sc_compat_exit, NR_compat_syscalls);
 133 };
 134
 135 static void syscall_entry_event_unknown(struct hlist_head *unknown_action_list_head,
 136         struct pt_regs *regs, long id)
 137 {
 138         unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 139         struct lttng_kernel_event_common_private *event_priv;
 140
 141         lttng_syscall_get_arguments(current, regs, args);
 142         lttng_hlist_for_each_entry_rcu(event_priv, unknown_action_list_head, u.syscall.node) {
 143                 if (unlikely(in_compat_syscall()))
 144                         __event_probe__compat_syscall_entry_unknown(event_priv->pub, id, args);
 145                 else
 146                         __event_probe__syscall_entry_unknown(event_priv->pub, id, args);
 147         }
 148 }
 149
 150 static __always_inline
 151 void syscall_entry_event_call_func(struct hlist_head *action_list,
 152                 void *func, unsigned int nrargs,
 153                 struct pt_regs *regs)
 154 {
 155         struct lttng_kernel_event_common_private *event_priv;
 156
 157         switch (nrargs) {
 158         case 0:
 159         {
 160                 void (*fptr)(void *__data) = func;
 161
 162                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 163                         fptr(event_priv->pub);
 164                 break;
 165         }
 166         case 1:
 167         {
 168                 void (*fptr)(void *__data, unsigned long arg0) = func;
 169                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 170
 171                 lttng_syscall_get_arguments(current, regs, args);
 172                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 173                         fptr(event_priv->pub, args[0]);
 174                 break;
 175         }
 176         case 2:
 177         {
 178                 void (*fptr)(void *__data,
 179                         unsigned long arg0,
 180                         unsigned long arg1) = func;
 181                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 182
 183                 lttng_syscall_get_arguments(current, regs, args);
 184                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 185                         fptr(event_priv->pub, args[0], args[1]);
 186                 break;
 187         }
 188         case 3:
 189         {
 190                 void (*fptr)(void *__data,
 191                         unsigned long arg0,
 192                         unsigned long arg1,
 193                         unsigned long arg2) = func;
 194                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 195
 196                 lttng_syscall_get_arguments(current, regs, args);
 197                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 198                         fptr(event_priv->pub, args[0], args[1], args[2]);
 199                 break;
 200         }
 201         case 4:
 202         {
 203                 void (*fptr)(void *__data,
 204                         unsigned long arg0,
 205                         unsigned long arg1,
 206                         unsigned long arg2,
 207                         unsigned long arg3) = func;
 208                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 209
 210                 lttng_syscall_get_arguments(current, regs, args);
 211                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 212                         fptr(event_priv->pub, args[0], args[1], args[2], args[3]);
 213                 break;
 214         }
 215         case 5:
 216         {
 217                 void (*fptr)(void *__data,
 218                         unsigned long arg0,
 219                         unsigned long arg1,
 220                         unsigned long arg2,
 221                         unsigned long arg3,
 222                         unsigned long arg4) = func;
 223                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 224
 225                 lttng_syscall_get_arguments(current, regs, args);
 226                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 227                         fptr(event_priv->pub, args[0], args[1], args[2], args[3], args[4]);
 228                 break;
 229         }
 230         case 6:
 231         {
 232                 void (*fptr)(void *__data,
 233                         unsigned long arg0,
 234                         unsigned long arg1,
 235                         unsigned long arg2,
 236                         unsigned long arg3,
 237                         unsigned long arg4,
 238                         unsigned long arg5) = func;
 239                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 240
 241                 lttng_syscall_get_arguments(current, regs, args);
 242                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 243                         fptr(event_priv->pub, args[0], args[1], args[2],
 244                              args[3], args[4], args[5]);
 245                 break;
 246         }
 247         default:
 248                 break;
 249         }
 250 }
 251
 252 void syscall_entry_event_probe(void *__data, struct pt_regs *regs, long id)
 253 {
 254         struct lttng_kernel_syscall_table *syscall_table = __data;
 255         struct hlist_head *action_list, *unknown_action_list;
 256         const struct trace_syscall_entry *table, *entry;
 257         size_t table_len;
 258
 259         if (unlikely(in_compat_syscall())) {
 260                 struct lttng_syscall_filter *filter = syscall_table->sc_filter;
 261
 262                 if (id < 0 || id >= NR_compat_syscalls
 263                         || (!READ_ONCE(syscall_table->syscall_all_entry) && !test_bit(id, filter->sc_compat_entry))) {
 264                         /* System call filtered out. */
 265                         return;
 266                 }
 267                 table = compat_sc_table.table;
 268                 table_len = compat_sc_table.len;
 269                 unknown_action_list = &syscall_table->compat_unknown_syscall_dispatch;
 270         } else {
 271                 struct lttng_syscall_filter *filter = syscall_table->sc_filter;
 272
 273                 if (id < 0 || id >= NR_syscalls
 274                         || (!READ_ONCE(syscall_table->syscall_all_entry) && !test_bit(id, filter->sc_entry))) {
 275                         /* System call filtered out. */
 276                         return;
 277                 }
 278                 table = sc_table.table;
 279                 table_len = sc_table.len;
 280                 unknown_action_list = &syscall_table->unknown_syscall_dispatch;
 281         }
 282         if (unlikely(id < 0 || id >= table_len)) {
 283                 syscall_entry_event_unknown(unknown_action_list, regs, id);
 284                 return;
 285         }
 286
 287         entry = &table[id];
 288         if (!entry->event_func) {
 289                 syscall_entry_event_unknown(unknown_action_list, regs, id);
 290                 return;
 291         }
 292
 293         if (unlikely(in_compat_syscall())) {
 294                 action_list = &syscall_table->compat_syscall_dispatch[id];
 295         } else {
 296                 action_list = &syscall_table->syscall_dispatch[id];
 297         }
 298         if (unlikely(hlist_empty(action_list)))
 299                 return;
 300
 301         syscall_entry_event_call_func(action_list, entry->event_func, entry->nrargs, regs);
 302 }
 303
 304 static void syscall_exit_event_unknown(struct hlist_head *unknown_action_list_head,
 305         struct pt_regs *regs, long id, long ret)
 306 {
 307         unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 308         struct lttng_kernel_event_common_private *event_priv;
 309
 310         lttng_syscall_get_arguments(current, regs, args);
 311         lttng_hlist_for_each_entry_rcu(event_priv, unknown_action_list_head, u.syscall.node) {
 312                 if (unlikely(in_compat_syscall()))
 313                         __event_probe__compat_syscall_exit_unknown(event_priv->pub, id, ret,
 314                                 args);
 315                 else
 316                         __event_probe__syscall_exit_unknown(event_priv->pub, id, ret, args);
 317         }
 318 }
 319
 320 static __always_inline
 321 void syscall_exit_event_call_func(struct hlist_head *action_list,
 322                 void *func, unsigned int nrargs,
 323                 struct pt_regs *regs, long ret)
 324 {
 325         struct lttng_kernel_event_common_private *event_priv;
 326
 327         switch (nrargs) {
 328         case 0:
 329         {
 330                 void (*fptr)(void *__data, long ret) = func;
 331
 332                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 333                         fptr(event_priv->pub, ret);
 334                 break;
 335         }
 336         case 1:
 337         {
 338                 void (*fptr)(void *__data,
 339                         long ret,
 340                         unsigned long arg0) = func;
 341                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 342
 343                 lttng_syscall_get_arguments(current, regs, args);
 344                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 345                         fptr(event_priv->pub, ret, args[0]);
 346                 break;
 347         }
 348         case 2:
 349         {
 350                 void (*fptr)(void *__data,
 351                         long ret,
 352                         unsigned long arg0,
 353                         unsigned long arg1) = func;
 354                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 355
 356                 lttng_syscall_get_arguments(current, regs, args);
 357                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 358                         fptr(event_priv->pub, ret, args[0], args[1]);
 359                 break;
 360         }
 361         case 3:
 362         {
 363                 void (*fptr)(void *__data,
 364                         long ret,
 365                         unsigned long arg0,
 366                         unsigned long arg1,
 367                         unsigned long arg2) = func;
 368                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 369
 370                 lttng_syscall_get_arguments(current, regs, args);
 371                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 372                         fptr(event_priv->pub, ret, args[0], args[1], args[2]);
 373                 break;
 374         }
 375         case 4:
 376         {
 377                 void (*fptr)(void *__data,
 378                         long ret,
 379                         unsigned long arg0,
 380                         unsigned long arg1,
 381                         unsigned long arg2,
 382                         unsigned long arg3) = func;
 383                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 384
 385                 lttng_syscall_get_arguments(current, regs, args);
 386                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 387                         fptr(event_priv->pub, ret, args[0], args[1], args[2], args[3]);
 388                 break;
 389         }
 390         case 5:
 391         {
 392                 void (*fptr)(void *__data,
 393                         long ret,
 394                         unsigned long arg0,
 395                         unsigned long arg1,
 396                         unsigned long arg2,
 397                         unsigned long arg3,
 398                         unsigned long arg4) = func;
 399                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 400
 401                 lttng_syscall_get_arguments(current, regs, args);
 402                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 403                         fptr(event_priv->pub, ret, args[0], args[1], args[2], args[3], args[4]);
 404                 break;
 405         }
 406         case 6:
 407         {
 408                 void (*fptr)(void *__data,
 409                         long ret,
 410                         unsigned long arg0,
 411                         unsigned long arg1,
 412                         unsigned long arg2,
 413                         unsigned long arg3,
 414                         unsigned long arg4,
 415                         unsigned long arg5) = func;
 416                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 417
 418                 lttng_syscall_get_arguments(current, regs, args);
 419                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 420                         fptr(event_priv->pub, ret, args[0], args[1], args[2],
 421                              args[3], args[4], args[5]);
 422                 break;
 423         }
 424         default:
 425                 break;
 426         }
 427 }
 428
 429 void syscall_exit_event_probe(void *__data, struct pt_regs *regs, long ret)
 430 {
 431         struct lttng_kernel_syscall_table *syscall_table = __data;
 432         struct hlist_head *action_list, *unknown_action_list;
 433         const struct trace_syscall_entry *table, *entry;
 434         size_t table_len;
 435         long id;
 436
 437         id = syscall_get_nr(current, regs);
 438
 439         if (unlikely(in_compat_syscall())) {
 440                 struct lttng_syscall_filter *filter = syscall_table->sc_filter;
 441
 442                 if (id < 0 || id >= NR_compat_syscalls
 443                         || (!READ_ONCE(syscall_table->syscall_all_exit) && !test_bit(id, filter->sc_compat_exit))) {
 444                         /* System call filtered out. */
 445                         return;
 446                 }
 447                 table = compat_sc_exit_table.table;
 448                 table_len = compat_sc_exit_table.len;
 449                 unknown_action_list = &syscall_table->compat_unknown_syscall_exit_dispatch;
 450         } else {
 451                 struct lttng_syscall_filter *filter = syscall_table->sc_filter;
 452
 453                 if (id < 0 || id >= NR_syscalls
 454                         || (!READ_ONCE(syscall_table->syscall_all_exit) && !test_bit(id, filter->sc_exit))) {
 455                         /* System call filtered out. */
 456                         return;
 457                 }
 458                 table = sc_exit_table.table;
 459                 table_len = sc_exit_table.len;
 460                 unknown_action_list = &syscall_table->unknown_syscall_exit_dispatch;
 461         }
 462         if (unlikely(id < 0 || id >= table_len)) {
 463                 syscall_exit_event_unknown(unknown_action_list, regs, id, ret);
 464                 return;
 465         }
 466
 467         entry = &table[id];
 468         if (!entry->event_func) {
 469                 syscall_exit_event_unknown(unknown_action_list, regs, id, ret);
 470                 return;
 471         }
 472
 473         if (unlikely(in_compat_syscall())) {
 474                 action_list = &syscall_table->compat_syscall_exit_dispatch[id];
 475         } else {
 476                 action_list = &syscall_table->syscall_exit_dispatch[id];
 477         }
 478         if (unlikely(hlist_empty(action_list)))
 479                 return;
 480
 481         syscall_exit_event_call_func(action_list, entry->event_func, entry->nrargs,
 482                                regs, ret);
 483 }
 484
 485 static
 486 struct lttng_kernel_syscall_table *get_syscall_table_from_enabler(struct lttng_event_enabler_common *event_enabler)
 487 {
 488         switch (event_enabler->enabler_type) {
 489         case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
 490         {
 491                 struct lttng_event_recorder_enabler *event_recorder_enabler =
 492                         container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
 493                 return &event_recorder_enabler->chan->priv->parent.syscall_table;
 494         }
 495         case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
 496         {
 497                 struct lttng_event_notifier_enabler *event_notifier_enabler =
 498                         container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
 499                 return &event_notifier_enabler->group->syscall_table;
 500         }
 501         default:
 502                 return NULL;
 503         }
 504 }
 505
 506 static
 507 struct lttng_kernel_syscall_table *get_syscall_table_from_event(struct lttng_kernel_event_common *event)
 508 {
 509         switch (event->type) {
 510         case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
 511         {
 512                 struct lttng_kernel_event_recorder *event_recorder =
 513                         container_of(event, struct lttng_kernel_event_recorder, parent);
 514                 return &event_recorder->chan->priv->parent.syscall_table;
 515         }
 516         case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
 517         {
 518                 struct lttng_kernel_event_notifier *event_notifier =
 519                         container_of(event, struct lttng_kernel_event_notifier, parent);
 520                 return &event_notifier->priv->group->syscall_table;
 521         }
 522         default:
 523                 return NULL;
 524         }
 525 }
 526
 527 /*
 528  * noinline to diminish caller stack size.
 529  * Should be called with sessions lock held.
 530  */
 531 static
 532 int lttng_create_syscall_event_if_missing(const struct trace_syscall_entry *table, size_t table_len,
 533         struct hlist_head *chan_table, struct lttng_event_recorder_enabler *syscall_event_enabler,
 534         enum sc_type type)
 535 {
 536         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(&syscall_event_enabler->parent);
 537         struct lttng_kernel_channel_buffer *chan = syscall_event_enabler->chan;
 538         struct lttng_kernel_session *session = chan->parent.session;
 539         unsigned int i;
 540
 541         /* Allocate events for each syscall matching enabler, insert into table */
 542         for (i = 0; i < table_len; i++) {
 543                 const struct lttng_kernel_event_desc *desc = table[i].desc;
 544                 struct lttng_event_recorder_enabler *event_enabler;
 545                 struct lttng_kernel_abi_event ev;
 546                 struct lttng_kernel_event_recorder_private *event_recorder_priv;
 547                 struct lttng_kernel_event_recorder *event_recorder;
 548                 struct hlist_head *head;
 549                 bool found = false;
 550
 551                 if (!desc) {
 552                         /* Unknown syscall */
 553                         continue;
 554                 }
 555                 if (lttng_desc_match_enabler(desc,
 556                                 lttng_event_recorder_enabler_as_enabler(syscall_event_enabler)) <= 0)
 557                         continue;
 558                 /*
 559                  * Check if already created.
 560                  */
 561                 head = utils_borrow_hash_table_bucket(
 562                         session->priv->events_ht.table, LTTNG_EVENT_HT_SIZE,
 563                         desc->event_name);
 564                 lttng_hlist_for_each_entry(event_recorder_priv, head, hlist) {
 565                         if (event_recorder_priv->parent.desc == desc
 566                                 && get_syscall_table_from_event(event_recorder_priv->parent.pub) == syscall_table)
 567                                 found = true;
 568                 }
 569                 if (found)
 570                         continue;
 571
 572                 /* We need to create an event for this syscall/enabler. */
 573                 memset(&ev, 0, sizeof(ev));
 574                 switch (type) {
 575                 case SC_TYPE_ENTRY:
 576                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 577                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 578                         break;
 579                 case SC_TYPE_EXIT:
 580                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 581                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 582                         break;
 583                 case SC_TYPE_COMPAT_ENTRY:
 584                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 585                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 586                         break;
 587                 case SC_TYPE_COMPAT_EXIT:
 588                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 589                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 590                         break;
 591                 }
 592                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1);
 593                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 594                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 595                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 596                 if (!event_enabler) {
 597                         return -ENOMEM;
 598                 }
 599                 event_recorder = _lttng_kernel_event_recorder_create(event_enabler, desc);
 600                 WARN_ON_ONCE(!event_recorder);
 601                 lttng_event_enabler_destroy(&event_enabler->parent);
 602                 if (IS_ERR(event_recorder)) {
 603                         /*
 604                          * If something goes wrong in event registration
 605                          * after the first one, we have no choice but to
 606                          * leave the previous events in there, until
 607                          * deleted by session teardown.
 608                          */
 609                         return PTR_ERR(event_recorder);
 610                 }
 611                 hlist_add_head(&event_recorder->priv->parent.u.syscall.node, &chan_table[i]);
 612         }
 613         return 0;
 614 }
 615
 616 static
 617 int lttng_syscalls_populate_events(struct lttng_event_enabler_common *syscall_event_enabler)
 618 {
 619         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(syscall_event_enabler);
 620         struct lttng_event_recorder_enabler *event_recorder_enabler;
 621         struct lttng_kernel_channel_buffer *chan;
 622         struct lttng_kernel_abi_event ev;
 623         int ret;
 624
 625         if (syscall_event_enabler->enabler_type != LTTNG_EVENT_ENABLER_TYPE_RECORDER)
 626                 return 0;
 627         event_recorder_enabler = container_of(syscall_event_enabler, struct lttng_event_recorder_enabler, parent);
 628         chan = event_recorder_enabler->chan;
 629
 630         if (hlist_empty(&syscall_table->unknown_syscall_dispatch)) {
 631                 const struct lttng_kernel_event_desc *desc =
 632                         &__event_desc___syscall_entry_unknown;
 633                 struct lttng_kernel_event_recorder *event_recorder;
 634                 struct lttng_event_recorder_enabler *event_enabler;
 635
 636                 memset(&ev, 0, sizeof(ev));
 637                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 638                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 639                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 640                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 641                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 642                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 643                 if (!event_enabler) {
 644                         return -ENOMEM;
 645                 }
 646                 event_recorder = _lttng_kernel_event_recorder_create(event_enabler, desc);
 647                 lttng_event_enabler_destroy(&event_enabler->parent);
 648                 WARN_ON_ONCE(!event_recorder);
 649                 if (IS_ERR(event_recorder)) {
 650                         return PTR_ERR(event_recorder);
 651                 }
 652                 hlist_add_head(&event_recorder->priv->parent.u.syscall.node, &syscall_table->unknown_syscall_dispatch);
 653         }
 654
 655         if (hlist_empty(&syscall_table->compat_unknown_syscall_dispatch)) {
 656                 const struct lttng_kernel_event_desc *desc =
 657                         &__event_desc___compat_syscall_entry_unknown;
 658                 struct lttng_kernel_event_recorder *event_recorder;
 659                 struct lttng_event_recorder_enabler *event_enabler;
 660
 661                 memset(&ev, 0, sizeof(ev));
 662                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 663                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 664                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 665                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 666                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 667                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 668                 if (!event_enabler) {
 669                         return -ENOMEM;
 670                 }
 671                 event_recorder = _lttng_kernel_event_recorder_create(event_enabler, desc);
 672                 WARN_ON_ONCE(!event_recorder);
 673                 lttng_event_enabler_destroy(&event_enabler->parent);
 674                 if (IS_ERR(event_recorder)) {
 675                         return PTR_ERR(event_recorder);
 676                 }
 677                 hlist_add_head(&event_recorder->priv->parent.u.syscall.node, &syscall_table->compat_unknown_syscall_dispatch);
 678         }
 679
 680         if (hlist_empty(&syscall_table->compat_unknown_syscall_exit_dispatch)) {
 681                 const struct lttng_kernel_event_desc *desc =
 682                         &__event_desc___compat_syscall_exit_unknown;
 683                 struct lttng_kernel_event_recorder *event_recorder;
 684                 struct lttng_event_recorder_enabler *event_enabler;
 685
 686                 memset(&ev, 0, sizeof(ev));
 687                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 688                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 689                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 690                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 691                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 692                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 693                 if (!event_enabler) {
 694                         return -ENOMEM;
 695                 }
 696                 event_recorder = _lttng_kernel_event_recorder_create(event_enabler, desc);
 697                 WARN_ON_ONCE(!event_recorder);
 698                 lttng_event_enabler_destroy(&event_enabler->parent);
 699                 if (IS_ERR(event_recorder)) {
 700                         return PTR_ERR(event_recorder);
 701                 }
 702                 hlist_add_head(&event_recorder->priv->parent.u.syscall.node, &syscall_table->compat_unknown_syscall_exit_dispatch);
 703         }
 704
 705         if (hlist_empty(&syscall_table->unknown_syscall_exit_dispatch)) {
 706                 const struct lttng_kernel_event_desc *desc =
 707                         &__event_desc___syscall_exit_unknown;
 708                 struct lttng_kernel_event_recorder *event_recorder;
 709                 struct lttng_event_recorder_enabler *event_enabler;
 710
 711                 memset(&ev, 0, sizeof(ev));
 712                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 713                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 714                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 715                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 716                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 717                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 718                 if (!event_enabler) {
 719                         return -ENOMEM;
 720                 }
 721                 event_recorder = _lttng_kernel_event_recorder_create(event_enabler, desc);
 722                 WARN_ON_ONCE(!event_recorder);
 723                 lttng_event_enabler_destroy(&event_enabler->parent);
 724                 if (IS_ERR(event_recorder)) {
 725                         return PTR_ERR(event_recorder);
 726                 }
 727                 hlist_add_head(&event_recorder->priv->parent.u.syscall.node, &syscall_table->unknown_syscall_exit_dispatch);
 728         }
 729
 730         ret = lttng_create_syscall_event_if_missing(sc_table.table, sc_table.len,
 731                         syscall_table->syscall_dispatch, event_recorder_enabler, SC_TYPE_ENTRY);
 732         if (ret)
 733                 return ret;
 734         ret = lttng_create_syscall_event_if_missing(sc_exit_table.table, sc_exit_table.len,
 735                         syscall_table->syscall_exit_dispatch, event_recorder_enabler, SC_TYPE_EXIT);
 736         if (ret)
 737                 return ret;
 738
 739 #ifdef CONFIG_COMPAT
 740         ret = lttng_create_syscall_event_if_missing(compat_sc_table.table, compat_sc_table.len,
 741                         syscall_table->compat_syscall_dispatch, event_recorder_enabler, SC_TYPE_COMPAT_ENTRY);
 742         if (ret)
 743                 return ret;
 744         ret = lttng_create_syscall_event_if_missing(compat_sc_exit_table.table, compat_sc_exit_table.len,
 745                         syscall_table->compat_syscall_exit_dispatch, event_recorder_enabler, SC_TYPE_COMPAT_EXIT);
 746         if (ret)
 747                 return ret;
 748 #endif
 749         return ret;
 750 }
 751
 752 /*
 753  * Should be called with sessions lock held.
 754  */
 755 int lttng_syscalls_register_event(struct lttng_event_enabler_common *syscall_event_enabler)
 756 {
 757         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(syscall_event_enabler);
 758         int ret;
 759
 760         if (!syscall_table->syscall_dispatch) {
 761                 /* create syscall table mapping syscall to events */
 762                 syscall_table->syscall_dispatch = kzalloc(sizeof(struct hlist_head) * sc_table.len, GFP_KERNEL);
 763                 if (!syscall_table->syscall_dispatch)
 764                         return -ENOMEM;
 765         }
 766         if (!syscall_table->syscall_exit_dispatch) {
 767                 /* create syscall table mapping syscall to events */
 768                 syscall_table->syscall_exit_dispatch = kzalloc(sizeof(struct hlist_head) * sc_exit_table.len, GFP_KERNEL);
 769                 if (!syscall_table->syscall_exit_dispatch)
 770                         return -ENOMEM;
 771         }
 772
 773
 774 #ifdef CONFIG_COMPAT
 775         if (!syscall_table->compat_syscall_dispatch) {
 776                 /* create syscall table mapping compat syscall to events */
 777                 syscall_table->compat_syscall_dispatch = kzalloc(sizeof(struct hlist_head) * compat_sc_table.len, GFP_KERNEL);
 778                 if (!syscall_table->compat_syscall_dispatch)
 779                         return -ENOMEM;
 780         }
 781
 782         if (!syscall_table->compat_syscall_exit_dispatch) {
 783                 /* create syscall table mapping compat syscall to events */
 784                 syscall_table->compat_syscall_exit_dispatch = kzalloc(sizeof(struct hlist_head) * compat_sc_exit_table.len, GFP_KERNEL);
 785                 if (!syscall_table->compat_syscall_exit_dispatch)
 786                         return -ENOMEM;
 787         }
 788 #endif
 789         if (!syscall_table->sc_filter) {
 790                 syscall_table->sc_filter = kzalloc(sizeof(struct lttng_syscall_filter),
 791                                 GFP_KERNEL);
 792                 if (!syscall_table->sc_filter)
 793                         return -ENOMEM;
 794         }
 795
 796         ret = lttng_syscalls_populate_events(syscall_event_enabler);
 797         if (ret)
 798                 return ret;
 799
 800         wrapper_vmalloc_sync_mappings();
 801
 802         if (!syscall_table->sys_enter_registered) {
 803                 ret = lttng_wrapper_tracepoint_probe_register("sys_enter",
 804                                 (void *) syscall_entry_event_probe, syscall_table);
 805                 if (ret)
 806                         return ret;
 807                 syscall_table->sys_enter_registered = 1;
 808         }
 809         if (!syscall_table->sys_exit_registered) {
 810                 ret = lttng_wrapper_tracepoint_probe_register("sys_exit",
 811                                 (void *) syscall_exit_event_probe, syscall_table);
 812                 if (ret) {
 813                         WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter",
 814                                 (void *) syscall_entry_event_probe, syscall_table));
 815                         return ret;
 816                 }
 817                 syscall_table->sys_exit_registered = 1;
 818         }
 819         return ret;
 820 }
 821
 822 static
 823 int create_unknown_event_notifier(
 824                 struct lttng_event_notifier_enabler *event_notifier_enabler,
 825                 enum sc_type type)
 826 {
 827         struct lttng_kernel_event_notifier_private *event_notifier_priv;
 828         struct lttng_kernel_event_notifier *event_notifier;
 829         const struct lttng_kernel_event_desc *desc;
 830         struct lttng_event_notifier_group *group = event_notifier_enabler->group;
 831         struct lttng_kernel_syscall_table *syscall_table = &group->syscall_table;
 832         struct lttng_kernel_abi_event_notifier event_notifier_param;
 833         uint64_t user_token = event_notifier_enabler->parent.user_token;
 834         uint64_t error_counter_index = event_notifier_enabler->error_counter_index;
 835         struct lttng_event_enabler_common *base_enabler = lttng_event_notifier_enabler_as_enabler(
 836                 event_notifier_enabler);
 837         struct hlist_head *unknown_dispatch_list;
 838         int ret = 0;
 839         bool found = false;
 840         enum lttng_kernel_abi_syscall_abi abi;
 841         enum lttng_kernel_abi_syscall_entryexit entryexit;
 842         struct hlist_head *head;
 843
 844         switch (type) {
 845         case SC_TYPE_ENTRY:
 846                 desc = &__event_desc___syscall_entry_unknown;
 847                 unknown_dispatch_list = &syscall_table->unknown_syscall_dispatch;
 848                 entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 849                 abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 850                 break;
 851         case SC_TYPE_EXIT:
 852                 desc = &__event_desc___syscall_exit_unknown;
 853                 unknown_dispatch_list = &syscall_table->unknown_syscall_exit_dispatch;
 854                 entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 855                 abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 856                 break;
 857         case SC_TYPE_COMPAT_ENTRY:
 858                 desc = &__event_desc___compat_syscall_entry_unknown;
 859                 unknown_dispatch_list = &syscall_table->compat_unknown_syscall_dispatch;
 860                 entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 861                 abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 862                 break;
 863         case SC_TYPE_COMPAT_EXIT:
 864                 desc = &__event_desc___compat_syscall_exit_unknown;
 865                 unknown_dispatch_list = &syscall_table->compat_unknown_syscall_exit_dispatch;
 866                 entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 867                 abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 868                 break;
 869         default:
 870                 BUG_ON(1);
 871         }
 872
 873         /*
 874          * Check if already created.
 875          */
 876         head = utils_borrow_hash_table_bucket(group->event_notifiers_ht.table,
 877                 LTTNG_EVENT_NOTIFIER_HT_SIZE, desc->event_name);
 878         lttng_hlist_for_each_entry(event_notifier_priv, head, hlist) {
 879                 if (event_notifier_priv->parent.desc == desc &&
 880                                 event_notifier_priv->parent.user_token == base_enabler->user_token)
 881                         found = true;
 882         }
 883         if (found)
 884                 goto end;
 885
 886         memset(&event_notifier_param, 0, sizeof(event_notifier_param));
 887         strncat(event_notifier_param.event.name, desc->event_name,
 888                 LTTNG_KERNEL_ABI_SYM_NAME_LEN - strlen(event_notifier_param.event.name) - 1);
 889
 890         event_notifier_param.event.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 891
 892         event_notifier_param.event.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 893         event_notifier_param.event.u.syscall.abi = abi;
 894         event_notifier_param.event.u.syscall.entryexit = entryexit;
 895
 896         event_notifier = _lttng_event_notifier_create(desc, user_token,
 897                 error_counter_index, group, &event_notifier_param,
 898                 event_notifier_param.event.instrumentation);
 899         if (IS_ERR(event_notifier)) {
 900                 printk(KERN_INFO "Unable to create unknown notifier %s\n",
 901                         desc->event_name);
 902                 ret = -ENOMEM;
 903                 goto end;
 904         }
 905
 906         hlist_add_head_rcu(&event_notifier->priv->parent.u.syscall.node, unknown_dispatch_list);
 907
 908 end:
 909         return ret;
 910 }
 911
 912 static int create_matching_event_notifiers(
 913                 struct lttng_event_notifier_enabler *event_notifier_enabler,
 914                 const struct trace_syscall_entry *table,
 915                 size_t table_len, enum sc_type type)
 916 {
 917         struct lttng_event_notifier_group *group = event_notifier_enabler->group;
 918         const struct lttng_kernel_event_desc *desc;
 919         uint64_t user_token = event_notifier_enabler->parent.user_token;
 920         uint64_t error_counter_index = event_notifier_enabler->error_counter_index;
 921         unsigned int i;
 922         int ret = 0;
 923
 924         /* iterate over all syscall and create event_notifier that match */
 925         for (i = 0; i < table_len; i++) {
 926                 struct lttng_kernel_event_notifier_private *event_notifier_priv;
 927                 struct lttng_kernel_event_notifier *event_notifier;
 928                 struct lttng_kernel_abi_event_notifier event_notifier_param;
 929                 struct hlist_head *head;
 930                 int found = 0;
 931
 932                 desc = table[i].desc;
 933                 if (!desc) {
 934                         /* Unknown syscall */
 935                         continue;
 936                 }
 937
 938                 if (!lttng_desc_match_enabler(desc,
 939                                 lttng_event_notifier_enabler_as_enabler(event_notifier_enabler)))
 940                         continue;
 941
 942                 /*
 943                  * Check if already created.
 944                  */
 945                 head = utils_borrow_hash_table_bucket(group->event_notifiers_ht.table,
 946                         LTTNG_EVENT_NOTIFIER_HT_SIZE, desc->event_name);
 947                 lttng_hlist_for_each_entry(event_notifier_priv, head, hlist) {
 948                         if (event_notifier_priv->parent.desc == desc
 949                                 && event_notifier_priv->parent.user_token == event_notifier_enabler->parent.user_token)
 950                                 found = 1;
 951                 }
 952                 if (found)
 953                         continue;
 954
 955                 memset(&event_notifier_param, 0, sizeof(event_notifier_param));
 956                 switch (type) {
 957                 case SC_TYPE_ENTRY:
 958                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 959                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 960                         break;
 961                 case SC_TYPE_EXIT:
 962                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 963                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 964                         break;
 965                 case SC_TYPE_COMPAT_ENTRY:
 966                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 967                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 968                         break;
 969                 case SC_TYPE_COMPAT_EXIT:
 970                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 971                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 972                         break;
 973                 }
 974                 strncat(event_notifier_param.event.name, desc->event_name,
 975                         LTTNG_KERNEL_ABI_SYM_NAME_LEN - strlen(event_notifier_param.event.name) - 1);
 976                 event_notifier_param.event.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 977                 event_notifier_param.event.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 978
 979                 event_notifier = _lttng_event_notifier_create(desc, user_token,
 980                         error_counter_index, group, &event_notifier_param,
 981                         event_notifier_param.event.instrumentation);
 982                 if (IS_ERR(event_notifier)) {
 983                         printk(KERN_INFO "Unable to create event_notifier %s\n",
 984                                 desc->event_name);
 985                         ret = -ENOMEM;
 986                         goto end;
 987                 }
 988
 989                 event_notifier->priv->parent.u.syscall.syscall_id = i;
 990         }
 991
 992 end:
 993         return ret;
 994
 995 }
 996
 997 int lttng_syscalls_create_matching_event_notifiers(
 998                 struct lttng_event_notifier_enabler *event_notifier_enabler)
 999 {
1000         int ret;
1001         struct lttng_event_enabler_common *base_enabler =
1002                         lttng_event_notifier_enabler_as_enabler(event_notifier_enabler);
1003         enum lttng_kernel_abi_syscall_entryexit entryexit =
1004                         base_enabler->event_param.u.syscall.entryexit;
1005
1006         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
1007                 ret = create_matching_event_notifiers(event_notifier_enabler,
1008                         sc_table.table, sc_table.len, SC_TYPE_ENTRY);
1009                 if (ret)
1010                         goto end;
1011
1012                 ret = create_matching_event_notifiers(event_notifier_enabler,
1013                         compat_sc_table.table, compat_sc_table.len,
1014                         SC_TYPE_COMPAT_ENTRY);
1015                 if (ret)
1016                         goto end;
1017
1018                 ret = create_unknown_event_notifier(event_notifier_enabler,
1019                                 SC_TYPE_ENTRY);
1020                 if (ret)
1021                         goto end;
1022
1023                 ret = create_unknown_event_notifier(event_notifier_enabler,
1024                                 SC_TYPE_COMPAT_ENTRY);
1025                 if (ret)
1026                         goto end;
1027         }
1028
1029         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
1030                 ret = create_matching_event_notifiers(event_notifier_enabler,
1031                         sc_exit_table.table, sc_exit_table.len,
1032                         SC_TYPE_EXIT);
1033                 if (ret)
1034                         goto end;
1035
1036                 ret = create_unknown_event_notifier(event_notifier_enabler,
1037                                 SC_TYPE_EXIT);
1038                 if (ret)
1039                         goto end;
1040
1041                 ret = create_matching_event_notifiers(event_notifier_enabler,
1042                         compat_sc_exit_table.table, compat_sc_exit_table.len,
1043                         SC_TYPE_COMPAT_EXIT);
1044                 if (ret)
1045                         goto end;
1046
1047                 ret = create_unknown_event_notifier(event_notifier_enabler,
1048                                 SC_TYPE_COMPAT_EXIT);
1049                 if (ret)
1050                         goto end;
1051         }
1052
1053 end:
1054         return ret;
1055 }
1056
1057 int lttng_syscalls_unregister_syscall_table(struct lttng_kernel_syscall_table *syscall_table)
1058 {
1059         int ret;
1060
1061         if (!syscall_table->syscall_dispatch)
1062                 return 0;
1063         if (syscall_table->sys_enter_registered) {
1064                 ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter",
1065                                 (void *) syscall_entry_event_probe, syscall_table);
1066                 if (ret)
1067                         return ret;
1068                 syscall_table->sys_enter_registered = 0;
1069         }
1070         if (syscall_table->sys_exit_registered) {
1071                 ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit",
1072                                 (void *) syscall_exit_event_probe, syscall_table);
1073                 if (ret)
1074                         return ret;
1075                 syscall_table->sys_exit_registered = 0;
1076         }
1077         return 0;
1078 }
1079
1080 int lttng_syscalls_destroy_syscall_table(struct lttng_kernel_syscall_table *syscall_table)
1081 {
1082         kfree(syscall_table->syscall_dispatch);
1083         kfree(syscall_table->syscall_exit_dispatch);
1084 #ifdef CONFIG_COMPAT
1085         kfree(syscall_table->compat_syscall_dispatch);
1086         kfree(syscall_table->compat_syscall_exit_dispatch);
1087 #endif
1088         kfree(syscall_table->sc_filter);
1089         return 0;
1090 }
1091
1092 static
1093 int get_syscall_nr(const char *syscall_name)
1094 {
1095         int syscall_nr = -1;
1096         int i;
1097
1098         for (i = 0; i < sc_table.len; i++) {
1099                 const struct trace_syscall_entry *entry;
1100                 const char *it_name;
1101
1102                 entry = &sc_table.table[i];
1103                 if (!entry->desc)
1104                         continue;
1105                 it_name = entry->desc->event_name;
1106                 it_name += strlen(SYSCALL_ENTRY_STR);
1107                 if (!strcmp(syscall_name, it_name)) {
1108                         syscall_nr = i;
1109                         break;
1110                 }
1111         }
1112         return syscall_nr;
1113 }
1114
1115 static
1116 int get_compat_syscall_nr(const char *syscall_name)
1117 {
1118         int syscall_nr = -1;
1119         int i;
1120
1121         for (i = 0; i < compat_sc_table.len; i++) {
1122                 const struct trace_syscall_entry *entry;
1123                 const char *it_name;
1124
1125                 entry = &compat_sc_table.table[i];
1126                 if (!entry->desc)
1127                         continue;
1128                 it_name = entry->desc->event_name;
1129                 it_name += strlen(COMPAT_SYSCALL_ENTRY_STR);
1130                 if (!strcmp(syscall_name, it_name)) {
1131                         syscall_nr = i;
1132                         break;
1133                 }
1134         }
1135         return syscall_nr;
1136 }
1137
1138 static
1139 uint32_t get_sc_tables_len(void)
1140 {
1141         return sc_table.len + compat_sc_table.len;
1142 }
1143
1144 static
1145 const char *get_syscall_name(const char *desc_name,
1146                 enum lttng_syscall_abi abi,
1147                 enum lttng_syscall_entryexit entryexit)
1148 {
1149         size_t prefix_len = 0;
1150
1151
1152         switch (entryexit) {
1153         case LTTNG_SYSCALL_ENTRY:
1154                 switch (abi) {
1155                 case LTTNG_SYSCALL_ABI_NATIVE:
1156                         prefix_len = strlen(SYSCALL_ENTRY_STR);
1157                         break;
1158                 case LTTNG_SYSCALL_ABI_COMPAT:
1159                         prefix_len = strlen(COMPAT_SYSCALL_ENTRY_STR);
1160                         break;
1161                 }
1162                 break;
1163         case LTTNG_SYSCALL_EXIT:
1164                 switch (abi) {
1165                 case LTTNG_SYSCALL_ABI_NATIVE:
1166                         prefix_len = strlen(SYSCALL_EXIT_STR);
1167                         break;
1168                 case LTTNG_SYSCALL_ABI_COMPAT:
1169                         prefix_len = strlen(COMPAT_SYSCALL_EXIT_STR);
1170                         break;
1171                 }
1172                 break;
1173         }
1174         WARN_ON_ONCE(prefix_len == 0);
1175         return desc_name + prefix_len;
1176 }
1177
1178 static
1179 int lttng_syscall_filter_enable(
1180                 struct lttng_syscall_filter *filter,
1181                 const char *desc_name, enum lttng_syscall_abi abi,
1182                 enum lttng_syscall_entryexit entryexit)
1183 {
1184         const char *syscall_name;
1185         unsigned long *bitmap;
1186         int syscall_nr;
1187
1188         syscall_name = get_syscall_name(desc_name, abi, entryexit);
1189
1190         switch (abi) {
1191         case LTTNG_SYSCALL_ABI_NATIVE:
1192                 syscall_nr = get_syscall_nr(syscall_name);
1193                 break;
1194         case LTTNG_SYSCALL_ABI_COMPAT:
1195                 syscall_nr = get_compat_syscall_nr(syscall_name);
1196                 break;
1197         default:
1198                 return -EINVAL;
1199         }
1200         if (syscall_nr < 0)
1201                 return -ENOENT;
1202
1203         switch (entryexit) {
1204         case LTTNG_SYSCALL_ENTRY:
1205                 switch (abi) {
1206                 case LTTNG_SYSCALL_ABI_NATIVE:
1207                         bitmap = filter->sc_entry;
1208                         break;
1209                 case LTTNG_SYSCALL_ABI_COMPAT:
1210                         bitmap = filter->sc_compat_entry;
1211                         break;
1212                 default:
1213                         return -EINVAL;
1214                 }
1215                 break;
1216         case LTTNG_SYSCALL_EXIT:
1217                 switch (abi) {
1218                 case LTTNG_SYSCALL_ABI_NATIVE:
1219                         bitmap = filter->sc_exit;
1220                         break;
1221                 case LTTNG_SYSCALL_ABI_COMPAT:
1222                         bitmap = filter->sc_compat_exit;
1223                         break;
1224                 default:
1225                         return -EINVAL;
1226                 }
1227                 break;
1228         default:
1229                 return -EINVAL;
1230         }
1231         if (test_bit(syscall_nr, bitmap))
1232                 return -EEXIST;
1233         bitmap_set(bitmap, syscall_nr, 1);
1234         return 0;
1235 }
1236
1237 int lttng_syscall_filter_enable_event(struct lttng_kernel_event_common *event)
1238 {
1239         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event);
1240         int ret;
1241
1242         WARN_ON_ONCE(event->priv->instrumentation != LTTNG_KERNEL_ABI_SYSCALL);
1243
1244         ret = lttng_syscall_filter_enable(syscall_table->sc_filter,
1245                 event->priv->desc->event_name, event->priv->u.syscall.abi,
1246                 event->priv->u.syscall.entryexit);
1247         if (ret)
1248                 return ret;
1249
1250         switch (event->type) {
1251         case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1252                 break;
1253         case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1254         {
1255                 unsigned int syscall_id = event->priv->u.syscall.syscall_id;
1256                 struct hlist_head *dispatch_list;
1257
1258                 switch (event->priv->u.syscall.entryexit) {
1259                 case LTTNG_SYSCALL_ENTRY:
1260                         switch (event->priv->u.syscall.abi) {
1261                         case LTTNG_SYSCALL_ABI_NATIVE:
1262                                 dispatch_list = &syscall_table->syscall_dispatch[syscall_id];
1263                                 break;
1264                         case LTTNG_SYSCALL_ABI_COMPAT:
1265                                 dispatch_list = &syscall_table->compat_syscall_dispatch[syscall_id];
1266                                 break;
1267                         default:
1268                                 ret = -EINVAL;
1269                                 goto end;
1270                         }
1271                         break;
1272                 case LTTNG_SYSCALL_EXIT:
1273                         switch (event->priv->u.syscall.abi) {
1274                         case LTTNG_SYSCALL_ABI_NATIVE:
1275                                 dispatch_list = &syscall_table->syscall_exit_dispatch[syscall_id];
1276                                 break;
1277                         case LTTNG_SYSCALL_ABI_COMPAT:
1278                                 dispatch_list = &syscall_table->compat_syscall_exit_dispatch[syscall_id];
1279                                 break;
1280                         default:
1281                                 ret = -EINVAL;
1282                                 goto end;
1283                         }
1284                         break;
1285                 default:
1286                         ret = -EINVAL;
1287                         goto end;
1288                 }
1289
1290                 hlist_add_head_rcu(&event->priv->u.syscall.node, dispatch_list);
1291                 break;
1292         }
1293         default:
1294                 WARN_ON_ONCE(1);
1295                 return -ENOSYS;
1296         }
1297 end:
1298         return ret;
1299 }
1300
1301 static
1302 int lttng_syscall_filter_disable(struct lttng_syscall_filter *filter,
1303                 const char *desc_name, enum lttng_syscall_abi abi,
1304                 enum lttng_syscall_entryexit entryexit)
1305 {
1306         const char *syscall_name;
1307         unsigned long *bitmap;
1308         int syscall_nr;
1309
1310         syscall_name = get_syscall_name(desc_name, abi, entryexit);
1311
1312         switch (abi) {
1313         case LTTNG_SYSCALL_ABI_NATIVE:
1314                 syscall_nr = get_syscall_nr(syscall_name);
1315                 break;
1316         case LTTNG_SYSCALL_ABI_COMPAT:
1317                 syscall_nr = get_compat_syscall_nr(syscall_name);
1318                 break;
1319         default:
1320                 return -EINVAL;
1321         }
1322         if (syscall_nr < 0)
1323                 return -ENOENT;
1324
1325         switch (entryexit) {
1326         case LTTNG_SYSCALL_ENTRY:
1327                 switch (abi) {
1328                 case LTTNG_SYSCALL_ABI_NATIVE:
1329                         bitmap = filter->sc_entry;
1330                         break;
1331                 case LTTNG_SYSCALL_ABI_COMPAT:
1332                         bitmap = filter->sc_compat_entry;
1333                         break;
1334                 default:
1335                         return -EINVAL;
1336                 }
1337                 break;
1338         case LTTNG_SYSCALL_EXIT:
1339                 switch (abi) {
1340                 case LTTNG_SYSCALL_ABI_NATIVE:
1341                         bitmap = filter->sc_exit;
1342                         break;
1343                 case LTTNG_SYSCALL_ABI_COMPAT:
1344                         bitmap = filter->sc_compat_exit;
1345                         break;
1346                 default:
1347                         return -EINVAL;
1348                 }
1349                 break;
1350         default:
1351                 return -EINVAL;
1352         }
1353         if (!test_bit(syscall_nr, bitmap))
1354                 return -EEXIST;
1355         bitmap_clear(bitmap, syscall_nr, 1);
1356
1357         return 0;
1358 }
1359
1360 int lttng_syscall_filter_disable_event(struct lttng_kernel_event_common *event)
1361 {
1362         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event);
1363         int ret;
1364
1365         ret = lttng_syscall_filter_disable(syscall_table->sc_filter,
1366                 event->priv->desc->event_name, event->priv->u.syscall.abi,
1367                 event->priv->u.syscall.entryexit);
1368         if (ret)
1369                 return ret;
1370
1371         switch (event->type) {
1372         case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1373                 break;
1374         case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1375         {
1376                 hlist_del_rcu(&event->priv->u.syscall.node);
1377                 break;
1378         }
1379         default:
1380                 WARN_ON_ONCE(1);
1381                 return -ENOSYS;
1382         }
1383         return 0;
1384 }
1385
1386 static
1387 const struct trace_syscall_entry *syscall_list_get_entry(loff_t *pos)
1388 {
1389         const struct trace_syscall_entry *entry;
1390         int iter = 0;
1391
1392         for (entry = sc_table.table;
1393                         entry < sc_table.table + sc_table.len;
1394                          entry++) {
1395                 if (iter++ >= *pos)
1396                         return entry;
1397         }
1398         for (entry = compat_sc_table.table;
1399                         entry < compat_sc_table.table + compat_sc_table.len;
1400                          entry++) {
1401                 if (iter++ >= *pos)
1402                         return entry;
1403         }
1404         /* End of list */
1405         return NULL;
1406 }
1407
1408 static
1409 void *syscall_list_start(struct seq_file *m, loff_t *pos)
1410 {
1411         return (void *) syscall_list_get_entry(pos);
1412 }
1413
1414 static
1415 void *syscall_list_next(struct seq_file *m, void *p, loff_t *ppos)
1416 {
1417         (*ppos)++;
1418         return (void *) syscall_list_get_entry(ppos);
1419 }
1420
1421 static
1422 void syscall_list_stop(struct seq_file *m, void *p)
1423 {
1424 }
1425
1426 static
1427 int get_sc_table(const struct trace_syscall_entry *entry,
1428                 const struct trace_syscall_entry **table,
1429                 unsigned int *bitness)
1430 {
1431         if (entry >= sc_table.table && entry < sc_table.table + sc_table.len) {
1432                 if (bitness)
1433                         *bitness = BITS_PER_LONG;
1434                 if (table)
1435                         *table = sc_table.table;
1436                 return 0;
1437         }
1438         if (!(entry >= compat_sc_table.table
1439                         && entry < compat_sc_table.table + compat_sc_table.len)) {
1440                 return -EINVAL;
1441         }
1442         if (bitness)
1443                 *bitness = 32;
1444         if (table)
1445                 *table = compat_sc_table.table;
1446         return 0;
1447 }
1448
1449 static
1450 int syscall_list_show(struct seq_file *m, void *p)
1451 {
1452         const struct trace_syscall_entry *table, *entry = p;
1453         unsigned int bitness;
1454         unsigned long index;
1455         int ret;
1456         const char *name;
1457
1458         ret = get_sc_table(entry, &table, &bitness);
1459         if (ret)
1460                 return ret;
1461         if (!entry->desc)
1462                 return 0;
1463         if (table == sc_table.table) {
1464                 index = entry - table;
1465                 name = &entry->desc->event_name[strlen(SYSCALL_ENTRY_STR)];
1466         } else {
1467                 index = (entry - table) + sc_table.len;
1468                 name = &entry->desc->event_name[strlen(COMPAT_SYSCALL_ENTRY_STR)];
1469         }
1470         seq_printf(m,   "syscall { index = %lu; name = %s; bitness = %u; };\n",
1471                 index, name, bitness);
1472         return 0;
1473 }
1474
1475 static
1476 const struct seq_operations lttng_syscall_list_seq_ops = {
1477         .start = syscall_list_start,
1478         .next = syscall_list_next,
1479         .stop = syscall_list_stop,
1480         .show = syscall_list_show,
1481 };
1482
1483 static
1484 int lttng_syscall_list_open(struct inode *inode, struct file *file)
1485 {
1486         return seq_open(file, &lttng_syscall_list_seq_ops);
1487 }
1488
1489 const struct file_operations lttng_syscall_list_fops = {
1490         .owner = THIS_MODULE,
1491         .open = lttng_syscall_list_open,
1492         .read = seq_read,
1493         .llseek = seq_lseek,
1494         .release = seq_release,
1495 };
1496
1497 /*
1498  * A syscall is enabled if it is traced for either entry or exit.
1499  */
1500 long lttng_syscall_table_get_active_mask(struct lttng_kernel_syscall_table *syscall_table,
1501                 struct lttng_kernel_abi_syscall_mask __user *usyscall_mask)
1502 {
1503         uint32_t len, sc_tables_len, bitmask_len;
1504         int ret = 0, bit;
1505         char *tmp_mask;
1506         struct lttng_syscall_filter *filter;
1507
1508         ret = get_user(len, &usyscall_mask->len);
1509         if (ret)
1510                 return ret;
1511         sc_tables_len = get_sc_tables_len();
1512         bitmask_len = ALIGN(sc_tables_len, 8) >> 3;
1513         if (len < sc_tables_len) {
1514                 return put_user(sc_tables_len, &usyscall_mask->len);
1515         }
1516         /* Array is large enough, we can copy array to user-space. */
1517         tmp_mask = kzalloc(bitmask_len, GFP_KERNEL);
1518         if (!tmp_mask)
1519                 return -ENOMEM;
1520         filter = syscall_table->sc_filter;
1521
1522         for (bit = 0; bit < sc_table.len; bit++) {
1523                 char state;
1524
1525                 if (syscall_table->syscall_dispatch) {
1526                         if (!(READ_ONCE(syscall_table->syscall_all_entry)
1527                                         || READ_ONCE(syscall_table->syscall_all_exit)) && filter)
1528                                 state = test_bit(bit, filter->sc_entry)
1529                                         || test_bit(bit, filter->sc_exit);
1530                         else
1531                                 state = 1;
1532                 } else {
1533                         state = 0;
1534                 }
1535                 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1536         }
1537         for (; bit < sc_tables_len; bit++) {
1538                 char state;
1539
1540                 if (syscall_table->compat_syscall_dispatch) {
1541                         if (!(READ_ONCE(syscall_table->syscall_all_entry)
1542                                         || READ_ONCE(syscall_table->syscall_all_exit)) && filter)
1543                                 state = test_bit(bit - sc_table.len,
1544                                                 filter->sc_compat_entry)
1545                                         || test_bit(bit - sc_table.len,
1546                                                 filter->sc_compat_exit);
1547                         else
1548                                 state = 1;
1549                 } else {
1550                         state = 0;
1551                 }
1552                 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1553         }
1554         if (copy_to_user(usyscall_mask->mask, tmp_mask, bitmask_len))
1555                 ret = -EFAULT;
1556         kfree(tmp_mask);
1557         return ret;
1558 }
1559
1560 int lttng_abi_syscall_list(void)
1561 {
1562         struct file *syscall_list_file;
1563         int file_fd, ret;
1564
1565         file_fd = lttng_get_unused_fd();
1566         if (file_fd < 0) {
1567                 ret = file_fd;
1568                 goto fd_error;
1569         }
1570
1571         syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
1572                                           &lttng_syscall_list_fops,
1573                                           NULL, O_RDWR);
1574         if (IS_ERR(syscall_list_file)) {
1575                 ret = PTR_ERR(syscall_list_file);
1576                 goto file_error;
1577         }
1578         ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
1579         if (ret < 0)
1580                 goto open_error;
1581         fd_install(file_fd, syscall_list_file);
1582         return file_fd;
1583
1584 open_error:
1585         fput(syscall_list_file);
1586 file_error:
1587         put_unused_fd(file_fd);
1588 fd_error:
1589         return ret;
1590 }