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
 136 int lttng_syscalls_create_matching_event_notifiers(struct lttng_event_enabler_common *event_enabler);
 137
 138 static void syscall_entry_event_unknown(struct hlist_head *unknown_action_list_head,
 139         struct pt_regs *regs, long id)
 140 {
 141         unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 142         struct lttng_kernel_event_common_private *event_priv;
 143
 144         lttng_syscall_get_arguments(current, regs, args);
 145         lttng_hlist_for_each_entry_rcu(event_priv, unknown_action_list_head, u.syscall.node) {
 146                 if (unlikely(in_compat_syscall()))
 147                         __event_probe__compat_syscall_entry_unknown(event_priv->pub, id, args);
 148                 else
 149                         __event_probe__syscall_entry_unknown(event_priv->pub, id, args);
 150         }
 151 }
 152
 153 static __always_inline
 154 void syscall_entry_event_call_func(struct hlist_head *action_list,
 155                 void *func, unsigned int nrargs,
 156                 struct pt_regs *regs)
 157 {
 158         struct lttng_kernel_event_common_private *event_priv;
 159
 160         switch (nrargs) {
 161         case 0:
 162         {
 163                 void (*fptr)(void *__data) = func;
 164
 165                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 166                         fptr(event_priv->pub);
 167                 break;
 168         }
 169         case 1:
 170         {
 171                 void (*fptr)(void *__data, unsigned long arg0) = func;
 172                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 173
 174                 lttng_syscall_get_arguments(current, regs, args);
 175                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 176                         fptr(event_priv->pub, args[0]);
 177                 break;
 178         }
 179         case 2:
 180         {
 181                 void (*fptr)(void *__data,
 182                         unsigned long arg0,
 183                         unsigned long arg1) = func;
 184                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 185
 186                 lttng_syscall_get_arguments(current, regs, args);
 187                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 188                         fptr(event_priv->pub, args[0], args[1]);
 189                 break;
 190         }
 191         case 3:
 192         {
 193                 void (*fptr)(void *__data,
 194                         unsigned long arg0,
 195                         unsigned long arg1,
 196                         unsigned long arg2) = func;
 197                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 198
 199                 lttng_syscall_get_arguments(current, regs, args);
 200                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 201                         fptr(event_priv->pub, args[0], args[1], args[2]);
 202                 break;
 203         }
 204         case 4:
 205         {
 206                 void (*fptr)(void *__data,
 207                         unsigned long arg0,
 208                         unsigned long arg1,
 209                         unsigned long arg2,
 210                         unsigned long arg3) = func;
 211                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 212
 213                 lttng_syscall_get_arguments(current, regs, args);
 214                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 215                         fptr(event_priv->pub, args[0], args[1], args[2], args[3]);
 216                 break;
 217         }
 218         case 5:
 219         {
 220                 void (*fptr)(void *__data,
 221                         unsigned long arg0,
 222                         unsigned long arg1,
 223                         unsigned long arg2,
 224                         unsigned long arg3,
 225                         unsigned long arg4) = func;
 226                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 227
 228                 lttng_syscall_get_arguments(current, regs, args);
 229                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 230                         fptr(event_priv->pub, args[0], args[1], args[2], args[3], args[4]);
 231                 break;
 232         }
 233         case 6:
 234         {
 235                 void (*fptr)(void *__data,
 236                         unsigned long arg0,
 237                         unsigned long arg1,
 238                         unsigned long arg2,
 239                         unsigned long arg3,
 240                         unsigned long arg4,
 241                         unsigned long arg5) = func;
 242                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 243
 244                 lttng_syscall_get_arguments(current, regs, args);
 245                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 246                         fptr(event_priv->pub, args[0], args[1], args[2],
 247                              args[3], args[4], args[5]);
 248                 break;
 249         }
 250         default:
 251                 break;
 252         }
 253 }
 254
 255 void syscall_entry_event_probe(void *__data, struct pt_regs *regs, long id)
 256 {
 257         struct lttng_kernel_syscall_table *syscall_table = __data;
 258         struct hlist_head *action_list, *unknown_action_list;
 259         const struct trace_syscall_entry *table, *entry;
 260         size_t table_len;
 261
 262         if (unlikely(in_compat_syscall())) {
 263                 struct lttng_syscall_filter *filter = syscall_table->sc_filter;
 264
 265                 if (id < 0 || id >= NR_compat_syscalls
 266                         || (!READ_ONCE(syscall_table->syscall_all_entry) && !test_bit(id, filter->sc_compat_entry))) {
 267                         /* System call filtered out. */
 268                         return;
 269                 }
 270                 table = compat_sc_table.table;
 271                 table_len = compat_sc_table.len;
 272                 unknown_action_list = &syscall_table->compat_unknown_syscall_dispatch;
 273         } else {
 274                 struct lttng_syscall_filter *filter = syscall_table->sc_filter;
 275
 276                 if (id < 0 || id >= NR_syscalls
 277                         || (!READ_ONCE(syscall_table->syscall_all_entry) && !test_bit(id, filter->sc_entry))) {
 278                         /* System call filtered out. */
 279                         return;
 280                 }
 281                 table = sc_table.table;
 282                 table_len = sc_table.len;
 283                 unknown_action_list = &syscall_table->unknown_syscall_dispatch;
 284         }
 285         if (unlikely(id < 0 || id >= table_len)) {
 286                 syscall_entry_event_unknown(unknown_action_list, regs, id);
 287                 return;
 288         }
 289
 290         entry = &table[id];
 291         if (!entry->event_func) {
 292                 syscall_entry_event_unknown(unknown_action_list, regs, id);
 293                 return;
 294         }
 295
 296         if (unlikely(in_compat_syscall())) {
 297                 action_list = &syscall_table->compat_syscall_dispatch[id];
 298         } else {
 299                 action_list = &syscall_table->syscall_dispatch[id];
 300         }
 301         if (unlikely(hlist_empty(action_list)))
 302                 return;
 303
 304         syscall_entry_event_call_func(action_list, entry->event_func, entry->nrargs, regs);
 305 }
 306
 307 static void syscall_exit_event_unknown(struct hlist_head *unknown_action_list_head,
 308         struct pt_regs *regs, long id, long ret)
 309 {
 310         unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 311         struct lttng_kernel_event_common_private *event_priv;
 312
 313         lttng_syscall_get_arguments(current, regs, args);
 314         lttng_hlist_for_each_entry_rcu(event_priv, unknown_action_list_head, u.syscall.node) {
 315                 if (unlikely(in_compat_syscall()))
 316                         __event_probe__compat_syscall_exit_unknown(event_priv->pub, id, ret,
 317                                 args);
 318                 else
 319                         __event_probe__syscall_exit_unknown(event_priv->pub, id, ret, args);
 320         }
 321 }
 322
 323 static __always_inline
 324 void syscall_exit_event_call_func(struct hlist_head *action_list,
 325                 void *func, unsigned int nrargs,
 326                 struct pt_regs *regs, long ret)
 327 {
 328         struct lttng_kernel_event_common_private *event_priv;
 329
 330         switch (nrargs) {
 331         case 0:
 332         {
 333                 void (*fptr)(void *__data, long ret) = func;
 334
 335                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 336                         fptr(event_priv->pub, ret);
 337                 break;
 338         }
 339         case 1:
 340         {
 341                 void (*fptr)(void *__data,
 342                         long ret,
 343                         unsigned long arg0) = func;
 344                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 345
 346                 lttng_syscall_get_arguments(current, regs, args);
 347                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 348                         fptr(event_priv->pub, ret, args[0]);
 349                 break;
 350         }
 351         case 2:
 352         {
 353                 void (*fptr)(void *__data,
 354                         long ret,
 355                         unsigned long arg0,
 356                         unsigned long arg1) = func;
 357                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 358
 359                 lttng_syscall_get_arguments(current, regs, args);
 360                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 361                         fptr(event_priv->pub, ret, args[0], args[1]);
 362                 break;
 363         }
 364         case 3:
 365         {
 366                 void (*fptr)(void *__data,
 367                         long ret,
 368                         unsigned long arg0,
 369                         unsigned long arg1,
 370                         unsigned long arg2) = func;
 371                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 372
 373                 lttng_syscall_get_arguments(current, regs, args);
 374                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 375                         fptr(event_priv->pub, ret, args[0], args[1], args[2]);
 376                 break;
 377         }
 378         case 4:
 379         {
 380                 void (*fptr)(void *__data,
 381                         long ret,
 382                         unsigned long arg0,
 383                         unsigned long arg1,
 384                         unsigned long arg2,
 385                         unsigned long arg3) = func;
 386                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 387
 388                 lttng_syscall_get_arguments(current, regs, args);
 389                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 390                         fptr(event_priv->pub, ret, args[0], args[1], args[2], args[3]);
 391                 break;
 392         }
 393         case 5:
 394         {
 395                 void (*fptr)(void *__data,
 396                         long ret,
 397                         unsigned long arg0,
 398                         unsigned long arg1,
 399                         unsigned long arg2,
 400                         unsigned long arg3,
 401                         unsigned long arg4) = func;
 402                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 403
 404                 lttng_syscall_get_arguments(current, regs, args);
 405                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 406                         fptr(event_priv->pub, ret, args[0], args[1], args[2], args[3], args[4]);
 407                 break;
 408         }
 409         case 6:
 410         {
 411                 void (*fptr)(void *__data,
 412                         long ret,
 413                         unsigned long arg0,
 414                         unsigned long arg1,
 415                         unsigned long arg2,
 416                         unsigned long arg3,
 417                         unsigned long arg4,
 418                         unsigned long arg5) = func;
 419                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 420
 421                 lttng_syscall_get_arguments(current, regs, args);
 422                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 423                         fptr(event_priv->pub, ret, args[0], args[1], args[2],
 424                              args[3], args[4], args[5]);
 425                 break;
 426         }
 427         default:
 428                 break;
 429         }
 430 }
 431
 432 void syscall_exit_event_probe(void *__data, struct pt_regs *regs, long ret)
 433 {
 434         struct lttng_kernel_syscall_table *syscall_table = __data;
 435         struct hlist_head *action_list, *unknown_action_list;
 436         const struct trace_syscall_entry *table, *entry;
 437         size_t table_len;
 438         long id;
 439
 440         id = syscall_get_nr(current, regs);
 441
 442         if (unlikely(in_compat_syscall())) {
 443                 struct lttng_syscall_filter *filter = syscall_table->sc_filter;
 444
 445                 if (id < 0 || id >= NR_compat_syscalls
 446                         || (!READ_ONCE(syscall_table->syscall_all_exit) && !test_bit(id, filter->sc_compat_exit))) {
 447                         /* System call filtered out. */
 448                         return;
 449                 }
 450                 table = compat_sc_exit_table.table;
 451                 table_len = compat_sc_exit_table.len;
 452                 unknown_action_list = &syscall_table->compat_unknown_syscall_exit_dispatch;
 453         } else {
 454                 struct lttng_syscall_filter *filter = syscall_table->sc_filter;
 455
 456                 if (id < 0 || id >= NR_syscalls
 457                         || (!READ_ONCE(syscall_table->syscall_all_exit) && !test_bit(id, filter->sc_exit))) {
 458                         /* System call filtered out. */
 459                         return;
 460                 }
 461                 table = sc_exit_table.table;
 462                 table_len = sc_exit_table.len;
 463                 unknown_action_list = &syscall_table->unknown_syscall_exit_dispatch;
 464         }
 465         if (unlikely(id < 0 || id >= table_len)) {
 466                 syscall_exit_event_unknown(unknown_action_list, regs, id, ret);
 467                 return;
 468         }
 469
 470         entry = &table[id];
 471         if (!entry->event_func) {
 472                 syscall_exit_event_unknown(unknown_action_list, regs, id, ret);
 473                 return;
 474         }
 475
 476         if (unlikely(in_compat_syscall())) {
 477                 action_list = &syscall_table->compat_syscall_exit_dispatch[id];
 478         } else {
 479                 action_list = &syscall_table->syscall_exit_dispatch[id];
 480         }
 481         if (unlikely(hlist_empty(action_list)))
 482                 return;
 483
 484         syscall_exit_event_call_func(action_list, entry->event_func, entry->nrargs,
 485                                regs, ret);
 486 }
 487
 488 static
 489 struct lttng_kernel_syscall_table *get_syscall_table_from_enabler(struct lttng_event_enabler_common *event_enabler)
 490 {
 491         switch (event_enabler->enabler_type) {
 492         case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
 493         {
 494                 struct lttng_event_recorder_enabler *event_recorder_enabler =
 495                         container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
 496                 return &event_recorder_enabler->chan->priv->parent.syscall_table;
 497         }
 498         case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
 499         {
 500                 struct lttng_event_notifier_enabler *event_notifier_enabler =
 501                         container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
 502                 return &event_notifier_enabler->group->syscall_table;
 503         }
 504         default:
 505                 return NULL;
 506         }
 507 }
 508
 509 static
 510 struct lttng_kernel_syscall_table *get_syscall_table_from_event(struct lttng_kernel_event_common *event)
 511 {
 512         switch (event->type) {
 513         case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
 514         {
 515                 struct lttng_kernel_event_recorder *event_recorder =
 516                         container_of(event, struct lttng_kernel_event_recorder, parent);
 517                 return &event_recorder->chan->priv->parent.syscall_table;
 518         }
 519         case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
 520         {
 521                 struct lttng_kernel_event_notifier *event_notifier =
 522                         container_of(event, struct lttng_kernel_event_notifier, parent);
 523                 return &event_notifier->priv->group->syscall_table;
 524         }
 525         default:
 526                 return NULL;
 527         }
 528 }
 529
 530 /*
 531  * noinline to diminish caller stack size.
 532  * Should be called with sessions lock held.
 533  */
 534 static
 535 int lttng_create_syscall_event_if_missing(const struct trace_syscall_entry *table, size_t table_len,
 536         struct hlist_head *chan_table, struct lttng_event_recorder_enabler *syscall_event_enabler,
 537         enum sc_type type)
 538 {
 539         struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&syscall_event_enabler->parent);
 540         struct lttng_kernel_channel_buffer *chan = syscall_event_enabler->chan;
 541         unsigned int i;
 542
 543         /* Allocate events for each syscall matching enabler, insert into table */
 544         for (i = 0; i < table_len; i++) {
 545                 const struct lttng_kernel_event_desc *desc = table[i].desc;
 546                 struct lttng_event_recorder_enabler *event_enabler;
 547                 struct lttng_kernel_abi_event ev;
 548                 struct lttng_kernel_event_common *event;
 549                 struct lttng_kernel_event_common_private *event_priv;
 550                 struct hlist_head *head;
 551                 bool found = false;
 552
 553                 if (!desc) {
 554                         /* Unknown syscall */
 555                         continue;
 556                 }
 557                 if (!lttng_desc_match_enabler(desc,
 558                                 lttng_event_recorder_enabler_as_enabler(syscall_event_enabler)))
 559                         continue;
 560                 /*
 561                  * Check if already created.
 562                  */
 563                 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
 564                 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
 565                         if (lttng_event_enabler_desc_match_event(&syscall_event_enabler->parent, desc, event_priv->pub))
 566                                 found = true;
 567                 }
 568                 if (found)
 569                         continue;
 570
 571                 /* We need to create an event for this syscall/enabler. */
 572                 memset(&ev, 0, sizeof(ev));
 573                 switch (type) {
 574                 case SC_TYPE_ENTRY:
 575                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 576                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 577                         break;
 578                 case SC_TYPE_EXIT:
 579                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 580                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 581                         break;
 582                 case SC_TYPE_COMPAT_ENTRY:
 583                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 584                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 585                         break;
 586                 case SC_TYPE_COMPAT_EXIT:
 587                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 588                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 589                         break;
 590                 }
 591                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1);
 592                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 593                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 594                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 595                 if (!event_enabler) {
 596                         return -ENOMEM;
 597                 }
 598                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 599                 WARN_ON_ONCE(!event);
 600                 lttng_event_enabler_destroy(&event_enabler->parent);
 601                 if (IS_ERR(event)) {
 602                         /*
 603                          * If something goes wrong in event registration
 604                          * after the first one, we have no choice but to
 605                          * leave the previous events in there, until
 606                          * deleted by session teardown.
 607                          */
 608                         return PTR_ERR(event);
 609                 }
 610                 hlist_add_head(&event->priv->u.syscall.node, &chan_table[i]);
 611         }
 612         return 0;
 613 }
 614
 615 static
 616 int lttng_syscalls_populate_events(struct lttng_event_enabler_common *syscall_event_enabler)
 617 {
 618         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(syscall_event_enabler);
 619         struct lttng_event_recorder_enabler *event_recorder_enabler;
 620         struct lttng_kernel_channel_buffer *chan;
 621         struct lttng_kernel_abi_event ev;
 622         int ret;
 623
 624         if (syscall_event_enabler->enabler_type != LTTNG_EVENT_ENABLER_TYPE_RECORDER)
 625                 return 0;
 626         event_recorder_enabler = container_of(syscall_event_enabler, struct lttng_event_recorder_enabler, parent);
 627         chan = event_recorder_enabler->chan;
 628
 629         if (hlist_empty(&syscall_table->unknown_syscall_dispatch)) {
 630                 const struct lttng_kernel_event_desc *desc =
 631                         &__event_desc___syscall_entry_unknown;
 632                 struct lttng_kernel_event_common *event;
 633                 struct lttng_event_recorder_enabler *event_enabler;
 634
 635                 memset(&ev, 0, sizeof(ev));
 636                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 637                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 638                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 639                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 640                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 641                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 642                 if (!event_enabler) {
 643                         return -ENOMEM;
 644                 }
 645                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 646                 lttng_event_enabler_destroy(&event_enabler->parent);
 647                 WARN_ON_ONCE(!event);
 648                 if (IS_ERR(event)) {
 649                         return PTR_ERR(event);
 650                 }
 651                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->unknown_syscall_dispatch);
 652         }
 653
 654         if (hlist_empty(&syscall_table->compat_unknown_syscall_dispatch)) {
 655                 const struct lttng_kernel_event_desc *desc =
 656                         &__event_desc___compat_syscall_entry_unknown;
 657                 struct lttng_kernel_event_common *event;
 658                 struct lttng_event_recorder_enabler *event_enabler;
 659
 660                 memset(&ev, 0, sizeof(ev));
 661                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 662                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 663                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 664                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 665                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 666                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 667                 if (!event_enabler) {
 668                         return -ENOMEM;
 669                 }
 670                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 671                 WARN_ON_ONCE(!event);
 672                 lttng_event_enabler_destroy(&event_enabler->parent);
 673                 if (IS_ERR(event)) {
 674                         return PTR_ERR(event);
 675                 }
 676                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->compat_unknown_syscall_dispatch);
 677         }
 678
 679         if (hlist_empty(&syscall_table->compat_unknown_syscall_exit_dispatch)) {
 680                 const struct lttng_kernel_event_desc *desc =
 681                         &__event_desc___compat_syscall_exit_unknown;
 682                 struct lttng_kernel_event_common *event;
 683                 struct lttng_event_recorder_enabler *event_enabler;
 684
 685                 memset(&ev, 0, sizeof(ev));
 686                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 687                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 688                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 689                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 690                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 691                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 692                 if (!event_enabler) {
 693                         return -ENOMEM;
 694                 }
 695                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 696                 WARN_ON_ONCE(!event);
 697                 lttng_event_enabler_destroy(&event_enabler->parent);
 698                 if (IS_ERR(event)) {
 699                         return PTR_ERR(event);
 700                 }
 701                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->compat_unknown_syscall_exit_dispatch);
 702         }
 703
 704         if (hlist_empty(&syscall_table->unknown_syscall_exit_dispatch)) {
 705                 const struct lttng_kernel_event_desc *desc =
 706                         &__event_desc___syscall_exit_unknown;
 707                 struct lttng_kernel_event_common *event;
 708                 struct lttng_event_recorder_enabler *event_enabler;
 709
 710                 memset(&ev, 0, sizeof(ev));
 711                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 712                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 713                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 714                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 715                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 716                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 717                 if (!event_enabler) {
 718                         return -ENOMEM;
 719                 }
 720                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 721                 WARN_ON_ONCE(!event);
 722                 lttng_event_enabler_destroy(&event_enabler->parent);
 723                 if (IS_ERR(event)) {
 724                         return PTR_ERR(event);
 725                 }
 726                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->unknown_syscall_exit_dispatch);
 727         }
 728
 729         ret = lttng_create_syscall_event_if_missing(sc_table.table, sc_table.len,
 730                         syscall_table->syscall_dispatch, event_recorder_enabler, SC_TYPE_ENTRY);
 731         if (ret)
 732                 return ret;
 733         ret = lttng_create_syscall_event_if_missing(sc_exit_table.table, sc_exit_table.len,
 734                         syscall_table->syscall_exit_dispatch, event_recorder_enabler, SC_TYPE_EXIT);
 735         if (ret)
 736                 return ret;
 737
 738 #ifdef CONFIG_COMPAT
 739         ret = lttng_create_syscall_event_if_missing(compat_sc_table.table, compat_sc_table.len,
 740                         syscall_table->compat_syscall_dispatch, event_recorder_enabler, SC_TYPE_COMPAT_ENTRY);
 741         if (ret)
 742                 return ret;
 743         ret = lttng_create_syscall_event_if_missing(compat_sc_exit_table.table, compat_sc_exit_table.len,
 744                         syscall_table->compat_syscall_exit_dispatch, event_recorder_enabler, SC_TYPE_COMPAT_EXIT);
 745         if (ret)
 746                 return ret;
 747 #endif
 748         return ret;
 749 }
 750
 751 /*
 752  * Should be called with sessions lock held.
 753  */
 754 int lttng_event_enabler_create_syscall_events_if_missing(struct lttng_event_enabler_common *syscall_event_enabler)
 755 {
 756         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(syscall_event_enabler);
 757         int ret;
 758
 759         if (!syscall_table->syscall_dispatch) {
 760                 /* create syscall table mapping syscall to events */
 761                 syscall_table->syscall_dispatch = kzalloc(sizeof(struct hlist_head) * sc_table.len, GFP_KERNEL);
 762                 if (!syscall_table->syscall_dispatch)
 763                         return -ENOMEM;
 764         }
 765         if (!syscall_table->syscall_exit_dispatch) {
 766                 /* create syscall table mapping syscall to events */
 767                 syscall_table->syscall_exit_dispatch = kzalloc(sizeof(struct hlist_head) * sc_exit_table.len, GFP_KERNEL);
 768                 if (!syscall_table->syscall_exit_dispatch)
 769                         return -ENOMEM;
 770         }
 771
 772
 773 #ifdef CONFIG_COMPAT
 774         if (!syscall_table->compat_syscall_dispatch) {
 775                 /* create syscall table mapping compat syscall to events */
 776                 syscall_table->compat_syscall_dispatch = kzalloc(sizeof(struct hlist_head) * compat_sc_table.len, GFP_KERNEL);
 777                 if (!syscall_table->compat_syscall_dispatch)
 778                         return -ENOMEM;
 779         }
 780
 781         if (!syscall_table->compat_syscall_exit_dispatch) {
 782                 /* create syscall table mapping compat syscall to events */
 783                 syscall_table->compat_syscall_exit_dispatch = kzalloc(sizeof(struct hlist_head) * compat_sc_exit_table.len, GFP_KERNEL);
 784                 if (!syscall_table->compat_syscall_exit_dispatch)
 785                         return -ENOMEM;
 786         }
 787 #endif
 788         if (!syscall_table->sc_filter) {
 789                 syscall_table->sc_filter = kzalloc(sizeof(struct lttng_syscall_filter),
 790                                 GFP_KERNEL);
 791                 if (!syscall_table->sc_filter)
 792                         return -ENOMEM;
 793         }
 794
 795         ret = lttng_syscalls_populate_events(syscall_event_enabler);
 796         if (ret)
 797                 return ret;
 798
 799         if (!syscall_table->sys_enter_registered) {
 800                 ret = lttng_wrapper_tracepoint_probe_register("sys_enter",
 801                                 (void *) syscall_entry_event_probe, syscall_table);
 802                 if (ret)
 803                         return ret;
 804                 syscall_table->sys_enter_registered = 1;
 805         }
 806         if (!syscall_table->sys_exit_registered) {
 807                 ret = lttng_wrapper_tracepoint_probe_register("sys_exit",
 808                                 (void *) syscall_exit_event_probe, syscall_table);
 809                 if (ret) {
 810                         WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter",
 811                                 (void *) syscall_entry_event_probe, syscall_table));
 812                         return ret;
 813                 }
 814                 syscall_table->sys_exit_registered = 1;
 815         }
 816
 817         ret = lttng_syscalls_create_matching_event_notifiers(syscall_event_enabler);
 818         if (ret)
 819                 return ret;
 820
 821         return ret;
 822 }
 823
 824 static
 825 int create_unknown_event_notifier(
 826                 struct lttng_event_notifier_enabler *event_notifier_enabler,
 827                 enum sc_type type)
 828 {
 829         struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&event_notifier_enabler->parent);
 830         struct lttng_kernel_event_common_private *event_priv;
 831         struct lttng_kernel_event_common *event;
 832         const struct lttng_kernel_event_desc *desc;
 833         struct lttng_event_notifier_group *group = event_notifier_enabler->group;
 834         struct lttng_kernel_syscall_table *syscall_table = &group->syscall_table;
 835         struct lttng_kernel_abi_event_notifier event_notifier_param;
 836         uint64_t user_token = event_notifier_enabler->parent.user_token;
 837         uint64_t error_counter_index = event_notifier_enabler->error_counter_index;
 838         struct lttng_event_enabler_common *base_enabler = lttng_event_notifier_enabler_as_enabler(
 839                 event_notifier_enabler);
 840         struct hlist_head *unknown_dispatch_list;
 841         int ret = 0;
 842         bool found = false;
 843         enum lttng_kernel_abi_syscall_abi abi;
 844         enum lttng_kernel_abi_syscall_entryexit entryexit;
 845         struct hlist_head *head;
 846
 847         switch (type) {
 848         case SC_TYPE_ENTRY:
 849                 desc = &__event_desc___syscall_entry_unknown;
 850                 unknown_dispatch_list = &syscall_table->unknown_syscall_dispatch;
 851                 entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 852                 abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 853                 break;
 854         case SC_TYPE_EXIT:
 855                 desc = &__event_desc___syscall_exit_unknown;
 856                 unknown_dispatch_list = &syscall_table->unknown_syscall_exit_dispatch;
 857                 entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 858                 abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 859                 break;
 860         case SC_TYPE_COMPAT_ENTRY:
 861                 desc = &__event_desc___compat_syscall_entry_unknown;
 862                 unknown_dispatch_list = &syscall_table->compat_unknown_syscall_dispatch;
 863                 entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 864                 abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 865                 break;
 866         case SC_TYPE_COMPAT_EXIT:
 867                 desc = &__event_desc___compat_syscall_exit_unknown;
 868                 unknown_dispatch_list = &syscall_table->compat_unknown_syscall_exit_dispatch;
 869                 entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 870                 abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 871                 break;
 872         default:
 873                 BUG_ON(1);
 874         }
 875
 876         /*
 877          * Check if already created.
 878          */
 879         head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
 880         lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
 881                 if (lttng_event_enabler_desc_match_event(base_enabler, desc, event_priv->pub))
 882                         found = true;
 883         }
 884         if (found)
 885                 goto end;
 886
 887         memset(&event_notifier_param, 0, sizeof(event_notifier_param));
 888         strncat(event_notifier_param.event.name, desc->event_name,
 889                 LTTNG_KERNEL_ABI_SYM_NAME_LEN - strlen(event_notifier_param.event.name) - 1);
 890
 891         event_notifier_param.event.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 892
 893         event_notifier_param.event.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 894         event_notifier_param.event.token = user_token;
 895         event_notifier_param.event.u.syscall.abi = abi;
 896         event_notifier_param.event.u.syscall.entryexit = entryexit;
 897         event_notifier_param.error_counter_index = error_counter_index;
 898
 899         event_notifier_enabler = lttng_event_notifier_enabler_create(LTTNG_ENABLER_FORMAT_NAME,
 900                         &event_notifier_param, group);
 901         WARN_ON_ONCE(!event_notifier_enabler);
 902         event = _lttng_kernel_event_create(&event_notifier_enabler->parent, desc);
 903         lttng_event_enabler_destroy(&event_notifier_enabler->parent);
 904         if (IS_ERR(event)) {
 905                 printk(KERN_INFO "Unable to create unknown notifier %s\n",
 906                         desc->event_name);
 907                 ret = -ENOMEM;
 908                 goto end;
 909         }
 910
 911         hlist_add_head_rcu(&event->priv->u.syscall.node, unknown_dispatch_list);
 912
 913 end:
 914         return ret;
 915 }
 916
 917 static int create_matching_event_notifiers(
 918                 struct lttng_event_notifier_enabler *syscall_event_notifier_enabler,
 919                 const struct trace_syscall_entry *table,
 920                 size_t table_len, enum sc_type type)
 921 {
 922         struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&syscall_event_notifier_enabler->parent);
 923         struct lttng_event_notifier_group *group = syscall_event_notifier_enabler->group;
 924         const struct lttng_kernel_event_desc *desc;
 925         uint64_t user_token = syscall_event_notifier_enabler->parent.user_token;
 926         uint64_t error_counter_index = syscall_event_notifier_enabler->error_counter_index;
 927         unsigned int i;
 928         int ret = 0;
 929
 930         /* iterate over all syscall and create event_notifier that match */
 931         for (i = 0; i < table_len; i++) {
 932                 struct lttng_event_notifier_enabler *event_notifier_enabler;
 933                 struct lttng_kernel_event_common_private *event_priv;
 934                 struct lttng_kernel_event_common *event;
 935                 struct lttng_kernel_abi_event_notifier event_notifier_param;
 936                 struct hlist_head *head;
 937                 int found = 0;
 938
 939                 desc = table[i].desc;
 940                 if (!desc) {
 941                         /* Unknown syscall */
 942                         continue;
 943                 }
 944
 945                 if (!lttng_desc_match_enabler(desc,
 946                                 lttng_event_notifier_enabler_as_enabler(syscall_event_notifier_enabler)))
 947                         continue;
 948
 949                 /*
 950                  * Check if already created.
 951                  */
 952                 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
 953                 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
 954                         if (lttng_event_enabler_desc_match_event(&syscall_event_notifier_enabler->parent, desc, event_priv->pub))
 955                                 found = 1;
 956                 }
 957                 if (found)
 958                         continue;
 959
 960                 memset(&event_notifier_param, 0, sizeof(event_notifier_param));
 961                 switch (type) {
 962                 case SC_TYPE_ENTRY:
 963                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 964                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 965                         break;
 966                 case SC_TYPE_EXIT:
 967                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 968                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 969                         break;
 970                 case SC_TYPE_COMPAT_ENTRY:
 971                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 972                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 973                         break;
 974                 case SC_TYPE_COMPAT_EXIT:
 975                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 976                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 977                         break;
 978                 }
 979                 strncat(event_notifier_param.event.name, desc->event_name,
 980                         LTTNG_KERNEL_ABI_SYM_NAME_LEN - strlen(event_notifier_param.event.name) - 1);
 981                 event_notifier_param.event.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 982                 event_notifier_param.event.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 983                 event_notifier_param.event.token = user_token;
 984                 event_notifier_param.error_counter_index = error_counter_index;
 985
 986                 event_notifier_enabler = lttng_event_notifier_enabler_create(LTTNG_ENABLER_FORMAT_NAME,
 987                                 &event_notifier_param, group);
 988                 WARN_ON_ONCE(!event_notifier_enabler);
 989                 event = _lttng_kernel_event_create(&event_notifier_enabler->parent, desc);
 990                 lttng_event_enabler_destroy(&event_notifier_enabler->parent);
 991                 if (IS_ERR(event)) {
 992                         printk(KERN_INFO "Unable to create event_notifier %s\n",
 993                                 desc->event_name);
 994                         ret = -ENOMEM;
 995                         goto end;
 996                 }
 997
 998                 event->priv->u.syscall.syscall_id = i;
 999         }
1000
1001 end:
1002         return ret;
1003
1004 }
1005
1006 static
1007 int lttng_syscalls_create_matching_event_notifiers(struct lttng_event_enabler_common *event_enabler)
1008 {
1009         int ret;
1010         enum lttng_kernel_abi_syscall_entryexit entryexit =
1011                         event_enabler->event_param.u.syscall.entryexit;
1012         struct lttng_event_notifier_enabler *event_notifier_enabler;
1013
1014         if (event_enabler->enabler_type != LTTNG_EVENT_ENABLER_TYPE_NOTIFIER)
1015                 return 0;
1016         event_notifier_enabler = container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
1017
1018         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
1019                 ret = create_matching_event_notifiers(event_notifier_enabler,
1020                         sc_table.table, sc_table.len, SC_TYPE_ENTRY);
1021                 if (ret)
1022                         goto end;
1023
1024                 ret = create_matching_event_notifiers(event_notifier_enabler,
1025                         compat_sc_table.table, compat_sc_table.len,
1026                         SC_TYPE_COMPAT_ENTRY);
1027                 if (ret)
1028                         goto end;
1029
1030                 ret = create_unknown_event_notifier(event_notifier_enabler,
1031                                 SC_TYPE_ENTRY);
1032                 if (ret)
1033                         goto end;
1034
1035                 ret = create_unknown_event_notifier(event_notifier_enabler,
1036                                 SC_TYPE_COMPAT_ENTRY);
1037                 if (ret)
1038                         goto end;
1039         }
1040
1041         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
1042                 ret = create_matching_event_notifiers(event_notifier_enabler,
1043                         sc_exit_table.table, sc_exit_table.len,
1044                         SC_TYPE_EXIT);
1045                 if (ret)
1046                         goto end;
1047
1048                 ret = create_unknown_event_notifier(event_notifier_enabler,
1049                                 SC_TYPE_EXIT);
1050                 if (ret)
1051                         goto end;
1052
1053                 ret = create_matching_event_notifiers(event_notifier_enabler,
1054                         compat_sc_exit_table.table, compat_sc_exit_table.len,
1055                         SC_TYPE_COMPAT_EXIT);
1056                 if (ret)
1057                         goto end;
1058
1059                 ret = create_unknown_event_notifier(event_notifier_enabler,
1060                                 SC_TYPE_COMPAT_EXIT);
1061                 if (ret)
1062                         goto end;
1063         }
1064
1065 end:
1066         return ret;
1067 }
1068
1069 int lttng_syscalls_unregister_syscall_table(struct lttng_kernel_syscall_table *syscall_table)
1070 {
1071         int ret;
1072
1073         if (!syscall_table->syscall_dispatch)
1074                 return 0;
1075         if (syscall_table->sys_enter_registered) {
1076                 ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter",
1077                                 (void *) syscall_entry_event_probe, syscall_table);
1078                 if (ret)
1079                         return ret;
1080                 syscall_table->sys_enter_registered = 0;
1081         }
1082         if (syscall_table->sys_exit_registered) {
1083                 ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit",
1084                                 (void *) syscall_exit_event_probe, syscall_table);
1085                 if (ret)
1086                         return ret;
1087                 syscall_table->sys_exit_registered = 0;
1088         }
1089         return 0;
1090 }
1091
1092 int lttng_syscalls_destroy_syscall_table(struct lttng_kernel_syscall_table *syscall_table)
1093 {
1094         kfree(syscall_table->syscall_dispatch);
1095         kfree(syscall_table->syscall_exit_dispatch);
1096 #ifdef CONFIG_COMPAT
1097         kfree(syscall_table->compat_syscall_dispatch);
1098         kfree(syscall_table->compat_syscall_exit_dispatch);
1099 #endif
1100         kfree(syscall_table->sc_filter);
1101         return 0;
1102 }
1103
1104 static
1105 int get_syscall_nr(const char *syscall_name)
1106 {
1107         int syscall_nr = -1;
1108         int i;
1109
1110         for (i = 0; i < sc_table.len; i++) {
1111                 const struct trace_syscall_entry *entry;
1112                 const char *it_name;
1113
1114                 entry = &sc_table.table[i];
1115                 if (!entry->desc)
1116                         continue;
1117                 it_name = entry->desc->event_name;
1118                 it_name += strlen(SYSCALL_ENTRY_STR);
1119                 if (!strcmp(syscall_name, it_name)) {
1120                         syscall_nr = i;
1121                         break;
1122                 }
1123         }
1124         return syscall_nr;
1125 }
1126
1127 static
1128 int get_compat_syscall_nr(const char *syscall_name)
1129 {
1130         int syscall_nr = -1;
1131         int i;
1132
1133         for (i = 0; i < compat_sc_table.len; i++) {
1134                 const struct trace_syscall_entry *entry;
1135                 const char *it_name;
1136
1137                 entry = &compat_sc_table.table[i];
1138                 if (!entry->desc)
1139                         continue;
1140                 it_name = entry->desc->event_name;
1141                 it_name += strlen(COMPAT_SYSCALL_ENTRY_STR);
1142                 if (!strcmp(syscall_name, it_name)) {
1143                         syscall_nr = i;
1144                         break;
1145                 }
1146         }
1147         return syscall_nr;
1148 }
1149
1150 static
1151 uint32_t get_sc_tables_len(void)
1152 {
1153         return sc_table.len + compat_sc_table.len;
1154 }
1155
1156 static
1157 const char *get_syscall_name(const char *desc_name,
1158                 enum lttng_syscall_abi abi,
1159                 enum lttng_syscall_entryexit entryexit)
1160 {
1161         size_t prefix_len = 0;
1162
1163
1164         switch (entryexit) {
1165         case LTTNG_SYSCALL_ENTRY:
1166                 switch (abi) {
1167                 case LTTNG_SYSCALL_ABI_NATIVE:
1168                         prefix_len = strlen(SYSCALL_ENTRY_STR);
1169                         break;
1170                 case LTTNG_SYSCALL_ABI_COMPAT:
1171                         prefix_len = strlen(COMPAT_SYSCALL_ENTRY_STR);
1172                         break;
1173                 }
1174                 break;
1175         case LTTNG_SYSCALL_EXIT:
1176                 switch (abi) {
1177                 case LTTNG_SYSCALL_ABI_NATIVE:
1178                         prefix_len = strlen(SYSCALL_EXIT_STR);
1179                         break;
1180                 case LTTNG_SYSCALL_ABI_COMPAT:
1181                         prefix_len = strlen(COMPAT_SYSCALL_EXIT_STR);
1182                         break;
1183                 }
1184                 break;
1185         }
1186         WARN_ON_ONCE(prefix_len == 0);
1187         return desc_name + prefix_len;
1188 }
1189
1190 static
1191 int lttng_syscall_filter_enable(
1192                 struct lttng_syscall_filter *filter,
1193                 const char *desc_name, enum lttng_syscall_abi abi,
1194                 enum lttng_syscall_entryexit entryexit)
1195 {
1196         const char *syscall_name;
1197         unsigned long *bitmap;
1198         int syscall_nr;
1199
1200         syscall_name = get_syscall_name(desc_name, abi, entryexit);
1201
1202         switch (abi) {
1203         case LTTNG_SYSCALL_ABI_NATIVE:
1204                 syscall_nr = get_syscall_nr(syscall_name);
1205                 break;
1206         case LTTNG_SYSCALL_ABI_COMPAT:
1207                 syscall_nr = get_compat_syscall_nr(syscall_name);
1208                 break;
1209         default:
1210                 return -EINVAL;
1211         }
1212         if (syscall_nr < 0)
1213                 return -ENOENT;
1214
1215         switch (entryexit) {
1216         case LTTNG_SYSCALL_ENTRY:
1217                 switch (abi) {
1218                 case LTTNG_SYSCALL_ABI_NATIVE:
1219                         bitmap = filter->sc_entry;
1220                         break;
1221                 case LTTNG_SYSCALL_ABI_COMPAT:
1222                         bitmap = filter->sc_compat_entry;
1223                         break;
1224                 default:
1225                         return -EINVAL;
1226                 }
1227                 break;
1228         case LTTNG_SYSCALL_EXIT:
1229                 switch (abi) {
1230                 case LTTNG_SYSCALL_ABI_NATIVE:
1231                         bitmap = filter->sc_exit;
1232                         break;
1233                 case LTTNG_SYSCALL_ABI_COMPAT:
1234                         bitmap = filter->sc_compat_exit;
1235                         break;
1236                 default:
1237                         return -EINVAL;
1238                 }
1239                 break;
1240         default:
1241                 return -EINVAL;
1242         }
1243         if (test_bit(syscall_nr, bitmap))
1244                 return -EEXIST;
1245         bitmap_set(bitmap, syscall_nr, 1);
1246         return 0;
1247 }
1248
1249 int lttng_syscall_filter_enable_event(struct lttng_kernel_event_common *event)
1250 {
1251         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event);
1252         int ret;
1253
1254         WARN_ON_ONCE(event->priv->instrumentation != LTTNG_KERNEL_ABI_SYSCALL);
1255
1256         ret = lttng_syscall_filter_enable(syscall_table->sc_filter,
1257                 event->priv->desc->event_name, event->priv->u.syscall.abi,
1258                 event->priv->u.syscall.entryexit);
1259         if (ret)
1260                 return ret;
1261
1262         switch (event->type) {
1263         case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1264                 break;
1265         case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1266         {
1267                 unsigned int syscall_id = event->priv->u.syscall.syscall_id;
1268                 struct hlist_head *dispatch_list;
1269
1270                 switch (event->priv->u.syscall.entryexit) {
1271                 case LTTNG_SYSCALL_ENTRY:
1272                         switch (event->priv->u.syscall.abi) {
1273                         case LTTNG_SYSCALL_ABI_NATIVE:
1274                                 dispatch_list = &syscall_table->syscall_dispatch[syscall_id];
1275                                 break;
1276                         case LTTNG_SYSCALL_ABI_COMPAT:
1277                                 dispatch_list = &syscall_table->compat_syscall_dispatch[syscall_id];
1278                                 break;
1279                         default:
1280                                 ret = -EINVAL;
1281                                 goto end;
1282                         }
1283                         break;
1284                 case LTTNG_SYSCALL_EXIT:
1285                         switch (event->priv->u.syscall.abi) {
1286                         case LTTNG_SYSCALL_ABI_NATIVE:
1287                                 dispatch_list = &syscall_table->syscall_exit_dispatch[syscall_id];
1288                                 break;
1289                         case LTTNG_SYSCALL_ABI_COMPAT:
1290                                 dispatch_list = &syscall_table->compat_syscall_exit_dispatch[syscall_id];
1291                                 break;
1292                         default:
1293                                 ret = -EINVAL;
1294                                 goto end;
1295                         }
1296                         break;
1297                 default:
1298                         ret = -EINVAL;
1299                         goto end;
1300                 }
1301
1302                 hlist_add_head_rcu(&event->priv->u.syscall.node, dispatch_list);
1303                 break;
1304         }
1305         default:
1306                 WARN_ON_ONCE(1);
1307                 return -ENOSYS;
1308         }
1309 end:
1310         return ret;
1311 }
1312
1313 static
1314 int lttng_syscall_filter_disable(struct lttng_syscall_filter *filter,
1315                 const char *desc_name, enum lttng_syscall_abi abi,
1316                 enum lttng_syscall_entryexit entryexit)
1317 {
1318         const char *syscall_name;
1319         unsigned long *bitmap;
1320         int syscall_nr;
1321
1322         syscall_name = get_syscall_name(desc_name, abi, entryexit);
1323
1324         switch (abi) {
1325         case LTTNG_SYSCALL_ABI_NATIVE:
1326                 syscall_nr = get_syscall_nr(syscall_name);
1327                 break;
1328         case LTTNG_SYSCALL_ABI_COMPAT:
1329                 syscall_nr = get_compat_syscall_nr(syscall_name);
1330                 break;
1331         default:
1332                 return -EINVAL;
1333         }
1334         if (syscall_nr < 0)
1335                 return -ENOENT;
1336
1337         switch (entryexit) {
1338         case LTTNG_SYSCALL_ENTRY:
1339                 switch (abi) {
1340                 case LTTNG_SYSCALL_ABI_NATIVE:
1341                         bitmap = filter->sc_entry;
1342                         break;
1343                 case LTTNG_SYSCALL_ABI_COMPAT:
1344                         bitmap = filter->sc_compat_entry;
1345                         break;
1346                 default:
1347                         return -EINVAL;
1348                 }
1349                 break;
1350         case LTTNG_SYSCALL_EXIT:
1351                 switch (abi) {
1352                 case LTTNG_SYSCALL_ABI_NATIVE:
1353                         bitmap = filter->sc_exit;
1354                         break;
1355                 case LTTNG_SYSCALL_ABI_COMPAT:
1356                         bitmap = filter->sc_compat_exit;
1357                         break;
1358                 default:
1359                         return -EINVAL;
1360                 }
1361                 break;
1362         default:
1363                 return -EINVAL;
1364         }
1365         if (!test_bit(syscall_nr, bitmap))
1366                 return -EEXIST;
1367         bitmap_clear(bitmap, syscall_nr, 1);
1368
1369         return 0;
1370 }
1371
1372 int lttng_syscall_filter_disable_event(struct lttng_kernel_event_common *event)
1373 {
1374         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event);
1375         int ret;
1376
1377         ret = lttng_syscall_filter_disable(syscall_table->sc_filter,
1378                 event->priv->desc->event_name, event->priv->u.syscall.abi,
1379                 event->priv->u.syscall.entryexit);
1380         if (ret)
1381                 return ret;
1382
1383         switch (event->type) {
1384         case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1385                 break;
1386         case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1387         {
1388                 hlist_del_rcu(&event->priv->u.syscall.node);
1389                 break;
1390         }
1391         default:
1392                 WARN_ON_ONCE(1);
1393                 return -ENOSYS;
1394         }
1395         return 0;
1396 }
1397
1398 void lttng_syscall_table_set_wildcard_all(struct lttng_event_enabler_common *event_enabler)
1399 {
1400         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(event_enabler);
1401         enum lttng_kernel_abi_syscall_entryexit entryexit;
1402         int enabled = event_enabler->enabled;
1403
1404         if (event_enabler->event_param.instrumentation != LTTNG_KERNEL_ABI_SYSCALL)
1405                 return;
1406         if (event_enabler->event_param.u.syscall.abi != LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL)
1407                 return;
1408         if (event_enabler->event_param.u.syscall.match != LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME)
1409                 return;
1410         if (strcmp(event_enabler->event_param.name, "*"))
1411                 return;
1412
1413         entryexit = event_enabler->event_param.u.syscall.entryexit;
1414         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
1415                 WRITE_ONCE(syscall_table->syscall_all_entry, enabled);
1416
1417         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
1418                 WRITE_ONCE(syscall_table->syscall_all_exit, enabled);
1419 }
1420
1421 static
1422 const struct trace_syscall_entry *syscall_list_get_entry(loff_t *pos)
1423 {
1424         const struct trace_syscall_entry *entry;
1425         int iter = 0;
1426
1427         for (entry = sc_table.table;
1428                         entry < sc_table.table + sc_table.len;
1429                          entry++) {
1430                 if (iter++ >= *pos)
1431                         return entry;
1432         }
1433         for (entry = compat_sc_table.table;
1434                         entry < compat_sc_table.table + compat_sc_table.len;
1435                          entry++) {
1436                 if (iter++ >= *pos)
1437                         return entry;
1438         }
1439         /* End of list */
1440         return NULL;
1441 }
1442
1443 static
1444 void *syscall_list_start(struct seq_file *m, loff_t *pos)
1445 {
1446         return (void *) syscall_list_get_entry(pos);
1447 }
1448
1449 static
1450 void *syscall_list_next(struct seq_file *m, void *p, loff_t *ppos)
1451 {
1452         (*ppos)++;
1453         return (void *) syscall_list_get_entry(ppos);
1454 }
1455
1456 static
1457 void syscall_list_stop(struct seq_file *m, void *p)
1458 {
1459 }
1460
1461 static
1462 int get_sc_table(const struct trace_syscall_entry *entry,
1463                 const struct trace_syscall_entry **table,
1464                 unsigned int *bitness)
1465 {
1466         if (entry >= sc_table.table && entry < sc_table.table + sc_table.len) {
1467                 if (bitness)
1468                         *bitness = BITS_PER_LONG;
1469                 if (table)
1470                         *table = sc_table.table;
1471                 return 0;
1472         }
1473         if (!(entry >= compat_sc_table.table
1474                         && entry < compat_sc_table.table + compat_sc_table.len)) {
1475                 return -EINVAL;
1476         }
1477         if (bitness)
1478                 *bitness = 32;
1479         if (table)
1480                 *table = compat_sc_table.table;
1481         return 0;
1482 }
1483
1484 static
1485 int syscall_list_show(struct seq_file *m, void *p)
1486 {
1487         const struct trace_syscall_entry *table, *entry = p;
1488         unsigned int bitness;
1489         unsigned long index;
1490         int ret;
1491         const char *name;
1492
1493         ret = get_sc_table(entry, &table, &bitness);
1494         if (ret)
1495                 return ret;
1496         if (!entry->desc)
1497                 return 0;
1498         if (table == sc_table.table) {
1499                 index = entry - table;
1500                 name = &entry->desc->event_name[strlen(SYSCALL_ENTRY_STR)];
1501         } else {
1502                 index = (entry - table) + sc_table.len;
1503                 name = &entry->desc->event_name[strlen(COMPAT_SYSCALL_ENTRY_STR)];
1504         }
1505         seq_printf(m,   "syscall { index = %lu; name = %s; bitness = %u; };\n",
1506                 index, name, bitness);
1507         return 0;
1508 }
1509
1510 static
1511 const struct seq_operations lttng_syscall_list_seq_ops = {
1512         .start = syscall_list_start,
1513         .next = syscall_list_next,
1514         .stop = syscall_list_stop,
1515         .show = syscall_list_show,
1516 };
1517
1518 static
1519 int lttng_syscall_list_open(struct inode *inode, struct file *file)
1520 {
1521         return seq_open(file, &lttng_syscall_list_seq_ops);
1522 }
1523
1524 const struct file_operations lttng_syscall_list_fops = {
1525         .owner = THIS_MODULE,
1526         .open = lttng_syscall_list_open,
1527         .read = seq_read,
1528         .llseek = seq_lseek,
1529         .release = seq_release,
1530 };
1531
1532 /*
1533  * A syscall is enabled if it is traced for either entry or exit.
1534  */
1535 long lttng_syscall_table_get_active_mask(struct lttng_kernel_syscall_table *syscall_table,
1536                 struct lttng_kernel_abi_syscall_mask __user *usyscall_mask)
1537 {
1538         uint32_t len, sc_tables_len, bitmask_len;
1539         int ret = 0, bit;
1540         char *tmp_mask;
1541         struct lttng_syscall_filter *filter;
1542
1543         ret = get_user(len, &usyscall_mask->len);
1544         if (ret)
1545                 return ret;
1546         sc_tables_len = get_sc_tables_len();
1547         bitmask_len = ALIGN(sc_tables_len, 8) >> 3;
1548         if (len < sc_tables_len) {
1549                 return put_user(sc_tables_len, &usyscall_mask->len);
1550         }
1551         /* Array is large enough, we can copy array to user-space. */
1552         tmp_mask = kzalloc(bitmask_len, GFP_KERNEL);
1553         if (!tmp_mask)
1554                 return -ENOMEM;
1555         filter = syscall_table->sc_filter;
1556
1557         for (bit = 0; bit < sc_table.len; bit++) {
1558                 char state;
1559
1560                 if (syscall_table->syscall_dispatch) {
1561                         if (!(READ_ONCE(syscall_table->syscall_all_entry)
1562                                         || READ_ONCE(syscall_table->syscall_all_exit)) && filter)
1563                                 state = test_bit(bit, filter->sc_entry)
1564                                         || test_bit(bit, filter->sc_exit);
1565                         else
1566                                 state = 1;
1567                 } else {
1568                         state = 0;
1569                 }
1570                 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1571         }
1572         for (; bit < sc_tables_len; bit++) {
1573                 char state;
1574
1575                 if (syscall_table->compat_syscall_dispatch) {
1576                         if (!(READ_ONCE(syscall_table->syscall_all_entry)
1577                                         || READ_ONCE(syscall_table->syscall_all_exit)) && filter)
1578                                 state = test_bit(bit - sc_table.len,
1579                                                 filter->sc_compat_entry)
1580                                         || test_bit(bit - sc_table.len,
1581                                                 filter->sc_compat_exit);
1582                         else
1583                                 state = 1;
1584                 } else {
1585                         state = 0;
1586                 }
1587                 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1588         }
1589         if (copy_to_user(usyscall_mask->mask, tmp_mask, bitmask_len))
1590                 ret = -EFAULT;
1591         kfree(tmp_mask);
1592         return ret;
1593 }
1594
1595 int lttng_abi_syscall_list(void)
1596 {
1597         struct file *syscall_list_file;
1598         int file_fd, ret;
1599
1600         file_fd = lttng_get_unused_fd();
1601         if (file_fd < 0) {
1602                 ret = file_fd;
1603                 goto fd_error;
1604         }
1605
1606         syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
1607                                           &lttng_syscall_list_fops,
1608                                           NULL, O_RDWR);
1609         if (IS_ERR(syscall_list_file)) {
1610                 ret = PTR_ERR(syscall_list_file);
1611                 goto file_error;
1612         }
1613         ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
1614         if (ret < 0)
1615                 goto open_error;
1616         fd_install(file_fd, syscall_list_file);
1617         return file_fd;
1618
1619 open_error:
1620         fput(syscall_list_file);
1621 file_error:
1622         put_unused_fd(file_fd);
1623 fd_error:
1624         return ret;
1625 }