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 static
 531 void lttng_syscall_event_enabler_create_event(struct lttng_event_enabler_common *syscall_event_enabler,
 532                 const struct lttng_kernel_event_desc *desc, struct hlist_head *dispatch_table,
 533                 enum sc_type type, unsigned int syscall_nr)
 534 {
 535         struct lttng_kernel_event_common *event;
 536
 537         switch (syscall_event_enabler->enabler_type) {
 538         case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
 539         {
 540                 struct lttng_event_recorder_enabler *syscall_event_recorder_enabler =
 541                         container_of(syscall_event_enabler, struct lttng_event_recorder_enabler, parent);
 542                 struct lttng_event_recorder_enabler *event_recorder_enabler;
 543                 struct lttng_kernel_abi_event ev;
 544
 545                 /* We need to create an event for this syscall/enabler. */
 546                 memset(&ev, 0, sizeof(ev));
 547                 switch (type) {
 548                 case SC_TYPE_ENTRY:
 549                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 550                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 551                         break;
 552                 case SC_TYPE_EXIT:
 553                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 554                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 555                         break;
 556                 case SC_TYPE_COMPAT_ENTRY:
 557                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 558                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 559                         break;
 560                 case SC_TYPE_COMPAT_EXIT:
 561                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 562                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 563                         break;
 564                 }
 565                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1);
 566                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 567                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 568                 event_recorder_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev,
 569                                 syscall_event_recorder_enabler->chan);
 570                 WARN_ON_ONCE(!event_recorder_enabler);
 571                 if (!event_recorder_enabler)
 572                         return;
 573                 event = _lttng_kernel_event_create(&event_recorder_enabler->parent, desc);
 574                 WARN_ON_ONCE(!event || IS_ERR(event));
 575                 lttng_event_enabler_destroy(&event_recorder_enabler->parent);
 576                 if (!event || IS_ERR(event)) {
 577                         printk(KERN_INFO "Unable to create event recorder %s\n", desc->event_name);
 578                         return;
 579                 }
 580                 if (dispatch_table)
 581                         hlist_add_head_rcu(&event->priv->u.syscall.node, &dispatch_table[syscall_nr]);
 582                 break;
 583         }
 584         case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
 585         {
 586                 struct lttng_event_notifier_enabler *syscall_event_notifier_enabler =
 587                         container_of(syscall_event_enabler, struct lttng_event_notifier_enabler, parent);
 588                 struct lttng_event_notifier_enabler *event_notifier_enabler;
 589                 struct lttng_kernel_abi_event_notifier event_notifier_param;
 590                 uint64_t user_token = syscall_event_enabler->user_token;
 591                 uint64_t error_counter_index = syscall_event_notifier_enabler->error_counter_index;
 592
 593                 memset(&event_notifier_param, 0, sizeof(event_notifier_param));
 594                 switch (type) {
 595                 case SC_TYPE_ENTRY:
 596                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 597                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 598                         break;
 599                 case SC_TYPE_EXIT:
 600                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 601                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 602                         break;
 603                 case SC_TYPE_COMPAT_ENTRY:
 604                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 605                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 606                         break;
 607                 case SC_TYPE_COMPAT_EXIT:
 608                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 609                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 610                         break;
 611                 }
 612                 strncat(event_notifier_param.event.name, desc->event_name,
 613                         LTTNG_KERNEL_ABI_SYM_NAME_LEN - strlen(event_notifier_param.event.name) - 1);
 614                 event_notifier_param.event.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 615                 event_notifier_param.event.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 616                 event_notifier_param.event.token = user_token;
 617                 event_notifier_param.error_counter_index = error_counter_index;
 618
 619                 event_notifier_enabler = lttng_event_notifier_enabler_create(LTTNG_ENABLER_FORMAT_NAME,
 620                                 &event_notifier_param, syscall_event_notifier_enabler->group);
 621                 WARN_ON_ONCE(!event_notifier_enabler);
 622                 event = _lttng_kernel_event_create(&event_notifier_enabler->parent, desc);
 623                 WARN_ON_ONCE(!event || IS_ERR(event));
 624                 lttng_event_enabler_destroy(&event_notifier_enabler->parent);
 625                 if (!event || IS_ERR(event)) {
 626                         printk(KERN_INFO "Unable to create event notifier %s\n", desc->event_name);
 627                         return;
 628                 }
 629                 event->priv->u.syscall.syscall_id = syscall_nr;
 630                 if (dispatch_table)
 631                         hlist_add_head_rcu(&event->priv->u.syscall.node, dispatch_table);
 632                 break;
 633         }
 634         default:
 635                 break;
 636         }
 637 }
 638
 639 static
 640 void lttng_syscall_event_enabler_create_matching_events(struct lttng_event_enabler_common *syscall_event_enabler_common,
 641                 const struct trace_syscall_entry *table,
 642                 size_t table_len,
 643                 struct hlist_head *dispatch_table,
 644                 enum sc_type type)
 645 {
 646         struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(syscall_event_enabler_common);
 647         const struct lttng_kernel_event_desc *desc;
 648         unsigned int i;
 649
 650         /* iterate over all syscall and create event_notifier that match */
 651         for (i = 0; i < table_len; i++) {
 652                 struct lttng_kernel_event_common_private *event_priv;
 653                 struct hlist_head *head;
 654                 int found = 0;
 655
 656                 desc = table[i].desc;
 657                 if (!desc) {
 658                         /* Unknown syscall */
 659                         continue;
 660                 }
 661
 662                 if (!lttng_desc_match_enabler(desc, syscall_event_enabler_common))
 663                         continue;
 664
 665                 /*
 666                  * Check if already created.
 667                  */
 668                 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
 669                 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
 670                         if (lttng_event_enabler_desc_match_event(syscall_event_enabler_common, desc, event_priv->pub))
 671                                 found = 1;
 672                 }
 673                 if (found)
 674                         continue;
 675
 676                 lttng_syscall_event_enabler_create_event(syscall_event_enabler_common, desc, dispatch_table, type, i);
 677         }
 678 }
 679
 680 static
 681 int lttng_syscalls_populate_events(struct lttng_event_enabler_common *syscall_event_enabler)
 682 {
 683         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(syscall_event_enabler);
 684         struct lttng_event_recorder_enabler *event_recorder_enabler;
 685         struct lttng_kernel_channel_buffer *chan;
 686         struct lttng_kernel_abi_event ev;
 687         int ret;
 688
 689         if (syscall_event_enabler->enabler_type != LTTNG_EVENT_ENABLER_TYPE_RECORDER)
 690                 return 0;
 691         event_recorder_enabler = container_of(syscall_event_enabler, struct lttng_event_recorder_enabler, parent);
 692         chan = event_recorder_enabler->chan;
 693
 694         if (hlist_empty(&syscall_table->unknown_syscall_dispatch)) {
 695                 const struct lttng_kernel_event_desc *desc =
 696                         &__event_desc___syscall_entry_unknown;
 697                 struct lttng_kernel_event_common *event;
 698                 struct lttng_event_recorder_enabler *event_enabler;
 699
 700                 memset(&ev, 0, sizeof(ev));
 701                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 702                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 703                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 704                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 705                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 706                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 707                 if (!event_enabler) {
 708                         return -ENOMEM;
 709                 }
 710                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 711                 lttng_event_enabler_destroy(&event_enabler->parent);
 712                 WARN_ON_ONCE(!event);
 713                 if (IS_ERR(event)) {
 714                         return PTR_ERR(event);
 715                 }
 716                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->unknown_syscall_dispatch);
 717         }
 718
 719         if (hlist_empty(&syscall_table->compat_unknown_syscall_dispatch)) {
 720                 const struct lttng_kernel_event_desc *desc =
 721                         &__event_desc___compat_syscall_entry_unknown;
 722                 struct lttng_kernel_event_common *event;
 723                 struct lttng_event_recorder_enabler *event_enabler;
 724
 725                 memset(&ev, 0, sizeof(ev));
 726                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 727                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 728                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 729                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 730                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 731                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 732                 if (!event_enabler) {
 733                         return -ENOMEM;
 734                 }
 735                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 736                 WARN_ON_ONCE(!event);
 737                 lttng_event_enabler_destroy(&event_enabler->parent);
 738                 if (IS_ERR(event)) {
 739                         return PTR_ERR(event);
 740                 }
 741                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->compat_unknown_syscall_dispatch);
 742         }
 743
 744         if (hlist_empty(&syscall_table->compat_unknown_syscall_exit_dispatch)) {
 745                 const struct lttng_kernel_event_desc *desc =
 746                         &__event_desc___compat_syscall_exit_unknown;
 747                 struct lttng_kernel_event_common *event;
 748                 struct lttng_event_recorder_enabler *event_enabler;
 749
 750                 memset(&ev, 0, sizeof(ev));
 751                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 752                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 753                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 754                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 755                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 756                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 757                 if (!event_enabler) {
 758                         return -ENOMEM;
 759                 }
 760                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 761                 WARN_ON_ONCE(!event);
 762                 lttng_event_enabler_destroy(&event_enabler->parent);
 763                 if (IS_ERR(event)) {
 764                         return PTR_ERR(event);
 765                 }
 766                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->compat_unknown_syscall_exit_dispatch);
 767         }
 768
 769         if (hlist_empty(&syscall_table->unknown_syscall_exit_dispatch)) {
 770                 const struct lttng_kernel_event_desc *desc =
 771                         &__event_desc___syscall_exit_unknown;
 772                 struct lttng_kernel_event_common *event;
 773                 struct lttng_event_recorder_enabler *event_enabler;
 774
 775                 memset(&ev, 0, sizeof(ev));
 776                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 777                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 778                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 779                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 780                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 781                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 782                 if (!event_enabler) {
 783                         return -ENOMEM;
 784                 }
 785                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 786                 WARN_ON_ONCE(!event);
 787                 lttng_event_enabler_destroy(&event_enabler->parent);
 788                 if (IS_ERR(event)) {
 789                         return PTR_ERR(event);
 790                 }
 791                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->unknown_syscall_exit_dispatch);
 792         }
 793
 794         lttng_syscall_event_enabler_create_matching_events(&event_recorder_enabler->parent, sc_table.table, sc_table.len,
 795                         syscall_table->syscall_dispatch, SC_TYPE_ENTRY);
 796         lttng_syscall_event_enabler_create_matching_events(&event_recorder_enabler->parent, sc_exit_table.table, sc_exit_table.len,
 797                         syscall_table->syscall_exit_dispatch, SC_TYPE_EXIT);
 798
 799 #ifdef CONFIG_COMPAT
 800         lttng_syscall_event_enabler_create_matching_events(&event_recorder_enabler->parent, compat_sc_table.table, compat_sc_table.len,
 801                         syscall_table->compat_syscall_dispatch, SC_TYPE_COMPAT_ENTRY);
 802         lttng_syscall_event_enabler_create_matching_events(&event_recorder_enabler->parent, compat_sc_exit_table.table, compat_sc_exit_table.len,
 803                         syscall_table->compat_syscall_exit_dispatch, SC_TYPE_COMPAT_EXIT);
 804 #endif
 805         return ret;
 806 }
 807
 808 /*
 809  * Should be called with sessions lock held.
 810  */
 811 int lttng_event_enabler_create_syscall_events_if_missing(struct lttng_event_enabler_common *syscall_event_enabler)
 812 {
 813         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(syscall_event_enabler);
 814         int ret;
 815
 816         if (!syscall_table->syscall_dispatch) {
 817                 /* create syscall table mapping syscall to events */
 818                 syscall_table->syscall_dispatch = kzalloc(sizeof(struct hlist_head) * sc_table.len, GFP_KERNEL);
 819                 if (!syscall_table->syscall_dispatch)
 820                         return -ENOMEM;
 821         }
 822         if (!syscall_table->syscall_exit_dispatch) {
 823                 /* create syscall table mapping syscall to events */
 824                 syscall_table->syscall_exit_dispatch = kzalloc(sizeof(struct hlist_head) * sc_exit_table.len, GFP_KERNEL);
 825                 if (!syscall_table->syscall_exit_dispatch)
 826                         return -ENOMEM;
 827         }
 828
 829
 830 #ifdef CONFIG_COMPAT
 831         if (!syscall_table->compat_syscall_dispatch) {
 832                 /* create syscall table mapping compat syscall to events */
 833                 syscall_table->compat_syscall_dispatch = kzalloc(sizeof(struct hlist_head) * compat_sc_table.len, GFP_KERNEL);
 834                 if (!syscall_table->compat_syscall_dispatch)
 835                         return -ENOMEM;
 836         }
 837
 838         if (!syscall_table->compat_syscall_exit_dispatch) {
 839                 /* create syscall table mapping compat syscall to events */
 840                 syscall_table->compat_syscall_exit_dispatch = kzalloc(sizeof(struct hlist_head) * compat_sc_exit_table.len, GFP_KERNEL);
 841                 if (!syscall_table->compat_syscall_exit_dispatch)
 842                         return -ENOMEM;
 843         }
 844 #endif
 845         if (!syscall_table->sc_filter) {
 846                 syscall_table->sc_filter = kzalloc(sizeof(struct lttng_syscall_filter),
 847                                 GFP_KERNEL);
 848                 if (!syscall_table->sc_filter)
 849                         return -ENOMEM;
 850         }
 851
 852         ret = lttng_syscalls_populate_events(syscall_event_enabler);
 853         if (ret)
 854                 return ret;
 855
 856         ret = lttng_syscalls_create_matching_event_notifiers(syscall_event_enabler);
 857         if (ret)
 858                 return ret;
 859
 860         if (!syscall_table->sys_enter_registered) {
 861                 ret = lttng_wrapper_tracepoint_probe_register("sys_enter",
 862                                 (void *) syscall_entry_event_probe, syscall_table);
 863                 if (ret)
 864                         return ret;
 865                 syscall_table->sys_enter_registered = 1;
 866         }
 867         if (!syscall_table->sys_exit_registered) {
 868                 ret = lttng_wrapper_tracepoint_probe_register("sys_exit",
 869                                 (void *) syscall_exit_event_probe, syscall_table);
 870                 if (ret) {
 871                         WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter",
 872                                 (void *) syscall_entry_event_probe, syscall_table));
 873                         return ret;
 874                 }
 875                 syscall_table->sys_exit_registered = 1;
 876         }
 877
 878         return ret;
 879 }
 880
 881 static
 882 void create_unknown_event_notifier(
 883                 struct lttng_event_notifier_enabler *event_notifier_enabler,
 884                 enum sc_type type)
 885 {
 886         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(&event_notifier_enabler->parent);
 887         struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&event_notifier_enabler->parent);
 888         struct lttng_kernel_event_common_private *event_priv;
 889         const struct lttng_kernel_event_desc *desc;
 890         struct hlist_head *unknown_dispatch_list;
 891         bool found = false;
 892         struct hlist_head *head;
 893
 894         switch (type) {
 895         case SC_TYPE_ENTRY:
 896                 desc = &__event_desc___syscall_entry_unknown;
 897                 unknown_dispatch_list = &syscall_table->unknown_syscall_dispatch;
 898                 break;
 899         case SC_TYPE_EXIT:
 900                 desc = &__event_desc___syscall_exit_unknown;
 901                 unknown_dispatch_list = &syscall_table->unknown_syscall_exit_dispatch;
 902                 break;
 903         case SC_TYPE_COMPAT_ENTRY:
 904                 desc = &__event_desc___compat_syscall_entry_unknown;
 905                 unknown_dispatch_list = &syscall_table->compat_unknown_syscall_dispatch;
 906                 break;
 907         case SC_TYPE_COMPAT_EXIT:
 908                 desc = &__event_desc___compat_syscall_exit_unknown;
 909                 unknown_dispatch_list = &syscall_table->compat_unknown_syscall_exit_dispatch;
 910                 break;
 911         default:
 912                 WARN_ON_ONCE(1);
 913         }
 914
 915         /*
 916          * Check if already created.
 917          */
 918         head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
 919         lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
 920                 if (lttng_event_enabler_desc_match_event(&event_notifier_enabler->parent, desc, event_priv->pub))
 921                         found = true;
 922         }
 923         if (!found)
 924                 lttng_syscall_event_enabler_create_event(&event_notifier_enabler->parent, desc, unknown_dispatch_list, type, -1U);
 925 }
 926
 927 static
 928 int lttng_syscalls_create_matching_event_notifiers(struct lttng_event_enabler_common *event_enabler)
 929 {
 930         int ret;
 931         enum lttng_kernel_abi_syscall_entryexit entryexit =
 932                         event_enabler->event_param.u.syscall.entryexit;
 933         struct lttng_event_notifier_enabler *event_notifier_enabler;
 934
 935         if (event_enabler->enabler_type != LTTNG_EVENT_ENABLER_TYPE_NOTIFIER)
 936                 return 0;
 937         event_notifier_enabler = container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
 938
 939         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
 940                 lttng_syscall_event_enabler_create_matching_events(&event_notifier_enabler->parent,
 941                         sc_table.table, sc_table.len, NULL, SC_TYPE_ENTRY);
 942                 lttng_syscall_event_enabler_create_matching_events(&event_notifier_enabler->parent,
 943                         compat_sc_table.table, compat_sc_table.len, NULL, SC_TYPE_COMPAT_ENTRY);
 944                 create_unknown_event_notifier(event_notifier_enabler, SC_TYPE_ENTRY);
 945                 create_unknown_event_notifier(event_notifier_enabler, SC_TYPE_COMPAT_ENTRY);
 946         }
 947
 948         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
 949                 lttng_syscall_event_enabler_create_matching_events(&event_notifier_enabler->parent,
 950                         sc_exit_table.table, sc_exit_table.len, NULL, SC_TYPE_EXIT);
 951                 lttng_syscall_event_enabler_create_matching_events(&event_notifier_enabler->parent,
 952                         compat_sc_exit_table.table, compat_sc_exit_table.len, NULL, SC_TYPE_COMPAT_EXIT);
 953                 create_unknown_event_notifier(event_notifier_enabler, SC_TYPE_EXIT);
 954                 create_unknown_event_notifier(event_notifier_enabler, SC_TYPE_COMPAT_EXIT);
 955         }
 956         return ret;
 957 }
 958
 959 int lttng_syscalls_unregister_syscall_table(struct lttng_kernel_syscall_table *syscall_table)
 960 {
 961         int ret;
 962
 963         if (!syscall_table->syscall_dispatch)
 964                 return 0;
 965         if (syscall_table->sys_enter_registered) {
 966                 ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter",
 967                                 (void *) syscall_entry_event_probe, syscall_table);
 968                 if (ret)
 969                         return ret;
 970                 syscall_table->sys_enter_registered = 0;
 971         }
 972         if (syscall_table->sys_exit_registered) {
 973                 ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit",
 974                                 (void *) syscall_exit_event_probe, syscall_table);
 975                 if (ret)
 976                         return ret;
 977                 syscall_table->sys_exit_registered = 0;
 978         }
 979         return 0;
 980 }
 981
 982 int lttng_syscalls_destroy_syscall_table(struct lttng_kernel_syscall_table *syscall_table)
 983 {
 984         kfree(syscall_table->syscall_dispatch);
 985         kfree(syscall_table->syscall_exit_dispatch);
 986 #ifdef CONFIG_COMPAT
 987         kfree(syscall_table->compat_syscall_dispatch);
 988         kfree(syscall_table->compat_syscall_exit_dispatch);
 989 #endif
 990         kfree(syscall_table->sc_filter);
 991         return 0;
 992 }
 993
 994 static
 995 int get_syscall_nr(const char *syscall_name)
 996 {
 997         int syscall_nr = -1;
 998         int i;
 999
1000         for (i = 0; i < sc_table.len; i++) {
1001                 const struct trace_syscall_entry *entry;
1002                 const char *it_name;
1003
1004                 entry = &sc_table.table[i];
1005                 if (!entry->desc)
1006                         continue;
1007                 it_name = entry->desc->event_name;
1008                 it_name += strlen(SYSCALL_ENTRY_STR);
1009                 if (!strcmp(syscall_name, it_name)) {
1010                         syscall_nr = i;
1011                         break;
1012                 }
1013         }
1014         return syscall_nr;
1015 }
1016
1017 static
1018 int get_compat_syscall_nr(const char *syscall_name)
1019 {
1020         int syscall_nr = -1;
1021         int i;
1022
1023         for (i = 0; i < compat_sc_table.len; i++) {
1024                 const struct trace_syscall_entry *entry;
1025                 const char *it_name;
1026
1027                 entry = &compat_sc_table.table[i];
1028                 if (!entry->desc)
1029                         continue;
1030                 it_name = entry->desc->event_name;
1031                 it_name += strlen(COMPAT_SYSCALL_ENTRY_STR);
1032                 if (!strcmp(syscall_name, it_name)) {
1033                         syscall_nr = i;
1034                         break;
1035                 }
1036         }
1037         return syscall_nr;
1038 }
1039
1040 static
1041 uint32_t get_sc_tables_len(void)
1042 {
1043         return sc_table.len + compat_sc_table.len;
1044 }
1045
1046 static
1047 const char *get_syscall_name(const char *desc_name,
1048                 enum lttng_syscall_abi abi,
1049                 enum lttng_syscall_entryexit entryexit)
1050 {
1051         size_t prefix_len = 0;
1052
1053
1054         switch (entryexit) {
1055         case LTTNG_SYSCALL_ENTRY:
1056                 switch (abi) {
1057                 case LTTNG_SYSCALL_ABI_NATIVE:
1058                         prefix_len = strlen(SYSCALL_ENTRY_STR);
1059                         break;
1060                 case LTTNG_SYSCALL_ABI_COMPAT:
1061                         prefix_len = strlen(COMPAT_SYSCALL_ENTRY_STR);
1062                         break;
1063                 }
1064                 break;
1065         case LTTNG_SYSCALL_EXIT:
1066                 switch (abi) {
1067                 case LTTNG_SYSCALL_ABI_NATIVE:
1068                         prefix_len = strlen(SYSCALL_EXIT_STR);
1069                         break;
1070                 case LTTNG_SYSCALL_ABI_COMPAT:
1071                         prefix_len = strlen(COMPAT_SYSCALL_EXIT_STR);
1072                         break;
1073                 }
1074                 break;
1075         }
1076         WARN_ON_ONCE(prefix_len == 0);
1077         return desc_name + prefix_len;
1078 }
1079
1080 static
1081 int lttng_syscall_filter_enable(
1082                 struct lttng_syscall_filter *filter,
1083                 const char *desc_name, enum lttng_syscall_abi abi,
1084                 enum lttng_syscall_entryexit entryexit)
1085 {
1086         const char *syscall_name;
1087         unsigned long *bitmap;
1088         int syscall_nr;
1089
1090         syscall_name = get_syscall_name(desc_name, abi, entryexit);
1091
1092         switch (abi) {
1093         case LTTNG_SYSCALL_ABI_NATIVE:
1094                 syscall_nr = get_syscall_nr(syscall_name);
1095                 break;
1096         case LTTNG_SYSCALL_ABI_COMPAT:
1097                 syscall_nr = get_compat_syscall_nr(syscall_name);
1098                 break;
1099         default:
1100                 return -EINVAL;
1101         }
1102         if (syscall_nr < 0)
1103                 return -ENOENT;
1104
1105         switch (entryexit) {
1106         case LTTNG_SYSCALL_ENTRY:
1107                 switch (abi) {
1108                 case LTTNG_SYSCALL_ABI_NATIVE:
1109                         bitmap = filter->sc_entry;
1110                         break;
1111                 case LTTNG_SYSCALL_ABI_COMPAT:
1112                         bitmap = filter->sc_compat_entry;
1113                         break;
1114                 default:
1115                         return -EINVAL;
1116                 }
1117                 break;
1118         case LTTNG_SYSCALL_EXIT:
1119                 switch (abi) {
1120                 case LTTNG_SYSCALL_ABI_NATIVE:
1121                         bitmap = filter->sc_exit;
1122                         break;
1123                 case LTTNG_SYSCALL_ABI_COMPAT:
1124                         bitmap = filter->sc_compat_exit;
1125                         break;
1126                 default:
1127                         return -EINVAL;
1128                 }
1129                 break;
1130         default:
1131                 return -EINVAL;
1132         }
1133         if (test_bit(syscall_nr, bitmap))
1134                 return -EEXIST;
1135         bitmap_set(bitmap, syscall_nr, 1);
1136         return 0;
1137 }
1138
1139 int lttng_syscall_filter_enable_event(struct lttng_kernel_event_common *event)
1140 {
1141         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event);
1142         int ret;
1143
1144         WARN_ON_ONCE(event->priv->instrumentation != LTTNG_KERNEL_ABI_SYSCALL);
1145
1146         ret = lttng_syscall_filter_enable(syscall_table->sc_filter,
1147                 event->priv->desc->event_name, event->priv->u.syscall.abi,
1148                 event->priv->u.syscall.entryexit);
1149         if (ret)
1150                 return ret;
1151
1152         switch (event->type) {
1153         case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1154                 break;
1155         case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1156         {
1157                 unsigned int syscall_id = event->priv->u.syscall.syscall_id;
1158                 struct hlist_head *dispatch_list;
1159
1160                 switch (event->priv->u.syscall.entryexit) {
1161                 case LTTNG_SYSCALL_ENTRY:
1162                         switch (event->priv->u.syscall.abi) {
1163                         case LTTNG_SYSCALL_ABI_NATIVE:
1164                                 dispatch_list = &syscall_table->syscall_dispatch[syscall_id];
1165                                 break;
1166                         case LTTNG_SYSCALL_ABI_COMPAT:
1167                                 dispatch_list = &syscall_table->compat_syscall_dispatch[syscall_id];
1168                                 break;
1169                         default:
1170                                 ret = -EINVAL;
1171                                 goto end;
1172                         }
1173                         break;
1174                 case LTTNG_SYSCALL_EXIT:
1175                         switch (event->priv->u.syscall.abi) {
1176                         case LTTNG_SYSCALL_ABI_NATIVE:
1177                                 dispatch_list = &syscall_table->syscall_exit_dispatch[syscall_id];
1178                                 break;
1179                         case LTTNG_SYSCALL_ABI_COMPAT:
1180                                 dispatch_list = &syscall_table->compat_syscall_exit_dispatch[syscall_id];
1181                                 break;
1182                         default:
1183                                 ret = -EINVAL;
1184                                 goto end;
1185                         }
1186                         break;
1187                 default:
1188                         ret = -EINVAL;
1189                         goto end;
1190                 }
1191
1192                 hlist_add_head_rcu(&event->priv->u.syscall.node, dispatch_list);
1193                 break;
1194         }
1195         default:
1196                 WARN_ON_ONCE(1);
1197                 return -ENOSYS;
1198         }
1199 end:
1200         return ret;
1201 }
1202
1203 static
1204 int lttng_syscall_filter_disable(struct lttng_syscall_filter *filter,
1205                 const char *desc_name, enum lttng_syscall_abi abi,
1206                 enum lttng_syscall_entryexit entryexit)
1207 {
1208         const char *syscall_name;
1209         unsigned long *bitmap;
1210         int syscall_nr;
1211
1212         syscall_name = get_syscall_name(desc_name, abi, entryexit);
1213
1214         switch (abi) {
1215         case LTTNG_SYSCALL_ABI_NATIVE:
1216                 syscall_nr = get_syscall_nr(syscall_name);
1217                 break;
1218         case LTTNG_SYSCALL_ABI_COMPAT:
1219                 syscall_nr = get_compat_syscall_nr(syscall_name);
1220                 break;
1221         default:
1222                 return -EINVAL;
1223         }
1224         if (syscall_nr < 0)
1225                 return -ENOENT;
1226
1227         switch (entryexit) {
1228         case LTTNG_SYSCALL_ENTRY:
1229                 switch (abi) {
1230                 case LTTNG_SYSCALL_ABI_NATIVE:
1231                         bitmap = filter->sc_entry;
1232                         break;
1233                 case LTTNG_SYSCALL_ABI_COMPAT:
1234                         bitmap = filter->sc_compat_entry;
1235                         break;
1236                 default:
1237                         return -EINVAL;
1238                 }
1239                 break;
1240         case LTTNG_SYSCALL_EXIT:
1241                 switch (abi) {
1242                 case LTTNG_SYSCALL_ABI_NATIVE:
1243                         bitmap = filter->sc_exit;
1244                         break;
1245                 case LTTNG_SYSCALL_ABI_COMPAT:
1246                         bitmap = filter->sc_compat_exit;
1247                         break;
1248                 default:
1249                         return -EINVAL;
1250                 }
1251                 break;
1252         default:
1253                 return -EINVAL;
1254         }
1255         if (!test_bit(syscall_nr, bitmap))
1256                 return -EEXIST;
1257         bitmap_clear(bitmap, syscall_nr, 1);
1258
1259         return 0;
1260 }
1261
1262 int lttng_syscall_filter_disable_event(struct lttng_kernel_event_common *event)
1263 {
1264         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event);
1265         int ret;
1266
1267         ret = lttng_syscall_filter_disable(syscall_table->sc_filter,
1268                 event->priv->desc->event_name, event->priv->u.syscall.abi,
1269                 event->priv->u.syscall.entryexit);
1270         if (ret)
1271                 return ret;
1272
1273         switch (event->type) {
1274         case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1275                 break;
1276         case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1277         {
1278                 hlist_del_rcu(&event->priv->u.syscall.node);
1279                 break;
1280         }
1281         default:
1282                 WARN_ON_ONCE(1);
1283                 return -ENOSYS;
1284         }
1285         return 0;
1286 }
1287
1288 void lttng_syscall_table_set_wildcard_all(struct lttng_event_enabler_common *event_enabler)
1289 {
1290         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(event_enabler);
1291         enum lttng_kernel_abi_syscall_entryexit entryexit;
1292         int enabled = event_enabler->enabled;
1293
1294         if (event_enabler->event_param.instrumentation != LTTNG_KERNEL_ABI_SYSCALL)
1295                 return;
1296         if (event_enabler->event_param.u.syscall.abi != LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL)
1297                 return;
1298         if (event_enabler->event_param.u.syscall.match != LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME)
1299                 return;
1300         if (strcmp(event_enabler->event_param.name, "*"))
1301                 return;
1302
1303         entryexit = event_enabler->event_param.u.syscall.entryexit;
1304         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
1305                 WRITE_ONCE(syscall_table->syscall_all_entry, enabled);
1306
1307         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
1308                 WRITE_ONCE(syscall_table->syscall_all_exit, enabled);
1309 }
1310
1311 static
1312 const struct trace_syscall_entry *syscall_list_get_entry(loff_t *pos)
1313 {
1314         const struct trace_syscall_entry *entry;
1315         int iter = 0;
1316
1317         for (entry = sc_table.table;
1318                         entry < sc_table.table + sc_table.len;
1319                          entry++) {
1320                 if (iter++ >= *pos)
1321                         return entry;
1322         }
1323         for (entry = compat_sc_table.table;
1324                         entry < compat_sc_table.table + compat_sc_table.len;
1325                          entry++) {
1326                 if (iter++ >= *pos)
1327                         return entry;
1328         }
1329         /* End of list */
1330         return NULL;
1331 }
1332
1333 static
1334 void *syscall_list_start(struct seq_file *m, loff_t *pos)
1335 {
1336         return (void *) syscall_list_get_entry(pos);
1337 }
1338
1339 static
1340 void *syscall_list_next(struct seq_file *m, void *p, loff_t *ppos)
1341 {
1342         (*ppos)++;
1343         return (void *) syscall_list_get_entry(ppos);
1344 }
1345
1346 static
1347 void syscall_list_stop(struct seq_file *m, void *p)
1348 {
1349 }
1350
1351 static
1352 int get_sc_table(const struct trace_syscall_entry *entry,
1353                 const struct trace_syscall_entry **table,
1354                 unsigned int *bitness)
1355 {
1356         if (entry >= sc_table.table && entry < sc_table.table + sc_table.len) {
1357                 if (bitness)
1358                         *bitness = BITS_PER_LONG;
1359                 if (table)
1360                         *table = sc_table.table;
1361                 return 0;
1362         }
1363         if (!(entry >= compat_sc_table.table
1364                         && entry < compat_sc_table.table + compat_sc_table.len)) {
1365                 return -EINVAL;
1366         }
1367         if (bitness)
1368                 *bitness = 32;
1369         if (table)
1370                 *table = compat_sc_table.table;
1371         return 0;
1372 }
1373
1374 static
1375 int syscall_list_show(struct seq_file *m, void *p)
1376 {
1377         const struct trace_syscall_entry *table, *entry = p;
1378         unsigned int bitness;
1379         unsigned long index;
1380         int ret;
1381         const char *name;
1382
1383         ret = get_sc_table(entry, &table, &bitness);
1384         if (ret)
1385                 return ret;
1386         if (!entry->desc)
1387                 return 0;
1388         if (table == sc_table.table) {
1389                 index = entry - table;
1390                 name = &entry->desc->event_name[strlen(SYSCALL_ENTRY_STR)];
1391         } else {
1392                 index = (entry - table) + sc_table.len;
1393                 name = &entry->desc->event_name[strlen(COMPAT_SYSCALL_ENTRY_STR)];
1394         }
1395         seq_printf(m,   "syscall { index = %lu; name = %s; bitness = %u; };\n",
1396                 index, name, bitness);
1397         return 0;
1398 }
1399
1400 static
1401 const struct seq_operations lttng_syscall_list_seq_ops = {
1402         .start = syscall_list_start,
1403         .next = syscall_list_next,
1404         .stop = syscall_list_stop,
1405         .show = syscall_list_show,
1406 };
1407
1408 static
1409 int lttng_syscall_list_open(struct inode *inode, struct file *file)
1410 {
1411         return seq_open(file, &lttng_syscall_list_seq_ops);
1412 }
1413
1414 const struct file_operations lttng_syscall_list_fops = {
1415         .owner = THIS_MODULE,
1416         .open = lttng_syscall_list_open,
1417         .read = seq_read,
1418         .llseek = seq_lseek,
1419         .release = seq_release,
1420 };
1421
1422 /*
1423  * A syscall is enabled if it is traced for either entry or exit.
1424  */
1425 long lttng_syscall_table_get_active_mask(struct lttng_kernel_syscall_table *syscall_table,
1426                 struct lttng_kernel_abi_syscall_mask __user *usyscall_mask)
1427 {
1428         uint32_t len, sc_tables_len, bitmask_len;
1429         int ret = 0, bit;
1430         char *tmp_mask;
1431         struct lttng_syscall_filter *filter;
1432
1433         ret = get_user(len, &usyscall_mask->len);
1434         if (ret)
1435                 return ret;
1436         sc_tables_len = get_sc_tables_len();
1437         bitmask_len = ALIGN(sc_tables_len, 8) >> 3;
1438         if (len < sc_tables_len) {
1439                 return put_user(sc_tables_len, &usyscall_mask->len);
1440         }
1441         /* Array is large enough, we can copy array to user-space. */
1442         tmp_mask = kzalloc(bitmask_len, GFP_KERNEL);
1443         if (!tmp_mask)
1444                 return -ENOMEM;
1445         filter = syscall_table->sc_filter;
1446
1447         for (bit = 0; bit < sc_table.len; bit++) {
1448                 char state;
1449
1450                 if (syscall_table->syscall_dispatch) {
1451                         if (!(READ_ONCE(syscall_table->syscall_all_entry)
1452                                         || READ_ONCE(syscall_table->syscall_all_exit)) && filter)
1453                                 state = test_bit(bit, filter->sc_entry)
1454                                         || test_bit(bit, filter->sc_exit);
1455                         else
1456                                 state = 1;
1457                 } else {
1458                         state = 0;
1459                 }
1460                 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1461         }
1462         for (; bit < sc_tables_len; bit++) {
1463                 char state;
1464
1465                 if (syscall_table->compat_syscall_dispatch) {
1466                         if (!(READ_ONCE(syscall_table->syscall_all_entry)
1467                                         || READ_ONCE(syscall_table->syscall_all_exit)) && filter)
1468                                 state = test_bit(bit - sc_table.len,
1469                                                 filter->sc_compat_entry)
1470                                         || test_bit(bit - sc_table.len,
1471                                                 filter->sc_compat_exit);
1472                         else
1473                                 state = 1;
1474                 } else {
1475                         state = 0;
1476                 }
1477                 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1478         }
1479         if (copy_to_user(usyscall_mask->mask, tmp_mask, bitmask_len))
1480                 ret = -EFAULT;
1481         kfree(tmp_mask);
1482         return ret;
1483 }
1484
1485 int lttng_abi_syscall_list(void)
1486 {
1487         struct file *syscall_list_file;
1488         int file_fd, ret;
1489
1490         file_fd = lttng_get_unused_fd();
1491         if (file_fd < 0) {
1492                 ret = file_fd;
1493                 goto fd_error;
1494         }
1495
1496         syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
1497                                           &lttng_syscall_list_fops,
1498                                           NULL, O_RDWR);
1499         if (IS_ERR(syscall_list_file)) {
1500                 ret = PTR_ERR(syscall_list_file);
1501                 goto file_error;
1502         }
1503         ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
1504         if (ret < 0)
1505                 goto open_error;
1506         fd_install(file_fd, syscall_list_file);
1507         return file_fd;
1508
1509 open_error:
1510         fput(syscall_list_file);
1511 file_error:
1512         put_unused_fd(file_fd);
1513 fd_error:
1514         return ret;
1515 }