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 bool lttng_syscall_event_enabler_is_wildcard_all(struct lttng_event_enabler_common *event_enabler)
 682 {
 683         if (event_enabler->event_param.instrumentation != LTTNG_KERNEL_ABI_SYSCALL)
 684                 return false;
 685         if (event_enabler->event_param.u.syscall.abi != LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL)
 686                 return false;
 687         if (event_enabler->event_param.u.syscall.match != LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME)
 688                 return false;
 689         if (strcmp(event_enabler->event_param.name, "*"))
 690                 return false;
 691         return true;
 692 }
 693
 694 static
 695 void create_unknown_syscall_event(struct lttng_event_enabler_common *event_enabler, enum sc_type type)
 696 {
 697         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(event_enabler);
 698         struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(event_enabler);
 699         struct lttng_kernel_event_common_private *event_priv;
 700         const struct lttng_kernel_event_desc *desc;
 701         struct hlist_head *unknown_dispatch_list;
 702         bool found = false;
 703         struct hlist_head *head;
 704
 705         /*
 706          * Considering that currently system calls can only be enabled on a per
 707          * name basis (or wildcard based on a name), unknown syscall events are
 708          * only used when matching *all* system calls, because this is the only
 709          * case which can be associated with an unknown system call.
 710          *
 711          * When enabling system call on a per system call number basis will be
 712          * supported, this will need to be revisited.
 713          */
 714         if (!lttng_syscall_event_enabler_is_wildcard_all(event_enabler))
 715                 return;
 716
 717         switch (type) {
 718         case SC_TYPE_ENTRY:
 719                 desc = &__event_desc___syscall_entry_unknown;
 720                 unknown_dispatch_list = &syscall_table->unknown_syscall_dispatch;
 721                 break;
 722         case SC_TYPE_EXIT:
 723                 desc = &__event_desc___syscall_exit_unknown;
 724                 unknown_dispatch_list = &syscall_table->unknown_syscall_exit_dispatch;
 725                 break;
 726         case SC_TYPE_COMPAT_ENTRY:
 727                 desc = &__event_desc___compat_syscall_entry_unknown;
 728                 unknown_dispatch_list = &syscall_table->compat_unknown_syscall_dispatch;
 729                 break;
 730         case SC_TYPE_COMPAT_EXIT:
 731                 desc = &__event_desc___compat_syscall_exit_unknown;
 732                 unknown_dispatch_list = &syscall_table->compat_unknown_syscall_exit_dispatch;
 733                 break;
 734         default:
 735                 WARN_ON_ONCE(1);
 736         }
 737
 738         /*
 739          * Check if already created.
 740          */
 741         head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
 742         lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
 743                 if (lttng_event_enabler_desc_match_event(event_enabler, desc, event_priv->pub))
 744                         found = true;
 745         }
 746         if (!found)
 747                 lttng_syscall_event_enabler_create_event(event_enabler, desc, unknown_dispatch_list, type, -1U);
 748 }
 749
 750 static
 751 int lttng_syscalls_populate_events(struct lttng_event_enabler_common *syscall_event_enabler)
 752 {
 753         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(syscall_event_enabler);
 754         struct lttng_event_recorder_enabler *event_recorder_enabler;
 755         struct lttng_kernel_channel_buffer *chan;
 756         int ret;
 757
 758         if (syscall_event_enabler->enabler_type != LTTNG_EVENT_ENABLER_TYPE_RECORDER)
 759                 return 0;
 760         event_recorder_enabler = container_of(syscall_event_enabler, struct lttng_event_recorder_enabler, parent);
 761         chan = event_recorder_enabler->chan;
 762
 763         lttng_syscall_event_enabler_create_matching_events(&event_recorder_enabler->parent, sc_table.table, sc_table.len,
 764                         syscall_table->syscall_dispatch, SC_TYPE_ENTRY);
 765         lttng_syscall_event_enabler_create_matching_events(&event_recorder_enabler->parent, sc_exit_table.table, sc_exit_table.len,
 766                         syscall_table->syscall_exit_dispatch, SC_TYPE_EXIT);
 767         create_unknown_syscall_event(syscall_event_enabler, SC_TYPE_ENTRY);
 768         create_unknown_syscall_event(syscall_event_enabler, SC_TYPE_EXIT);
 769
 770 #ifdef CONFIG_COMPAT
 771         lttng_syscall_event_enabler_create_matching_events(&event_recorder_enabler->parent, compat_sc_table.table, compat_sc_table.len,
 772                         syscall_table->compat_syscall_dispatch, SC_TYPE_COMPAT_ENTRY);
 773         lttng_syscall_event_enabler_create_matching_events(&event_recorder_enabler->parent, compat_sc_exit_table.table, compat_sc_exit_table.len,
 774                         syscall_table->compat_syscall_exit_dispatch, SC_TYPE_COMPAT_EXIT);
 775         create_unknown_syscall_event(syscall_event_enabler, SC_TYPE_COMPAT_ENTRY);
 776         create_unknown_syscall_event(syscall_event_enabler, SC_TYPE_COMPAT_EXIT);
 777 #endif
 778         return ret;
 779 }
 780
 781 /*
 782  * Should be called with sessions lock held.
 783  */
 784 int lttng_event_enabler_create_syscall_events_if_missing(struct lttng_event_enabler_common *syscall_event_enabler)
 785 {
 786         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(syscall_event_enabler);
 787         int ret;
 788
 789         if (!syscall_table->syscall_dispatch) {
 790                 /* create syscall table mapping syscall to events */
 791                 syscall_table->syscall_dispatch = kzalloc(sizeof(struct hlist_head) * sc_table.len, GFP_KERNEL);
 792                 if (!syscall_table->syscall_dispatch)
 793                         return -ENOMEM;
 794         }
 795         if (!syscall_table->syscall_exit_dispatch) {
 796                 /* create syscall table mapping syscall to events */
 797                 syscall_table->syscall_exit_dispatch = kzalloc(sizeof(struct hlist_head) * sc_exit_table.len, GFP_KERNEL);
 798                 if (!syscall_table->syscall_exit_dispatch)
 799                         return -ENOMEM;
 800         }
 801
 802
 803 #ifdef CONFIG_COMPAT
 804         if (!syscall_table->compat_syscall_dispatch) {
 805                 /* create syscall table mapping compat syscall to events */
 806                 syscall_table->compat_syscall_dispatch = kzalloc(sizeof(struct hlist_head) * compat_sc_table.len, GFP_KERNEL);
 807                 if (!syscall_table->compat_syscall_dispatch)
 808                         return -ENOMEM;
 809         }
 810
 811         if (!syscall_table->compat_syscall_exit_dispatch) {
 812                 /* create syscall table mapping compat syscall to events */
 813                 syscall_table->compat_syscall_exit_dispatch = kzalloc(sizeof(struct hlist_head) * compat_sc_exit_table.len, GFP_KERNEL);
 814                 if (!syscall_table->compat_syscall_exit_dispatch)
 815                         return -ENOMEM;
 816         }
 817 #endif
 818         if (!syscall_table->sc_filter) {
 819                 syscall_table->sc_filter = kzalloc(sizeof(struct lttng_syscall_filter),
 820                                 GFP_KERNEL);
 821                 if (!syscall_table->sc_filter)
 822                         return -ENOMEM;
 823         }
 824
 825         ret = lttng_syscalls_populate_events(syscall_event_enabler);
 826         if (ret)
 827                 return ret;
 828
 829         ret = lttng_syscalls_create_matching_event_notifiers(syscall_event_enabler);
 830         if (ret)
 831                 return ret;
 832
 833         if (!syscall_table->sys_enter_registered) {
 834                 ret = lttng_wrapper_tracepoint_probe_register("sys_enter",
 835                                 (void *) syscall_entry_event_probe, syscall_table);
 836                 if (ret)
 837                         return ret;
 838                 syscall_table->sys_enter_registered = 1;
 839         }
 840         if (!syscall_table->sys_exit_registered) {
 841                 ret = lttng_wrapper_tracepoint_probe_register("sys_exit",
 842                                 (void *) syscall_exit_event_probe, syscall_table);
 843                 if (ret) {
 844                         WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter",
 845                                 (void *) syscall_entry_event_probe, syscall_table));
 846                         return ret;
 847                 }
 848                 syscall_table->sys_exit_registered = 1;
 849         }
 850
 851         return ret;
 852 }
 853
 854 static
 855 int lttng_syscalls_create_matching_event_notifiers(struct lttng_event_enabler_common *event_enabler)
 856 {
 857         int ret;
 858         enum lttng_kernel_abi_syscall_entryexit entryexit =
 859                         event_enabler->event_param.u.syscall.entryexit;
 860         struct lttng_event_notifier_enabler *event_notifier_enabler;
 861
 862         if (event_enabler->enabler_type != LTTNG_EVENT_ENABLER_TYPE_NOTIFIER)
 863                 return 0;
 864         event_notifier_enabler = container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
 865
 866         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
 867                 lttng_syscall_event_enabler_create_matching_events(&event_notifier_enabler->parent,
 868                         sc_table.table, sc_table.len, NULL, SC_TYPE_ENTRY);
 869                 lttng_syscall_event_enabler_create_matching_events(&event_notifier_enabler->parent,
 870                         compat_sc_table.table, compat_sc_table.len, NULL, SC_TYPE_COMPAT_ENTRY);
 871                 create_unknown_syscall_event(event_enabler, SC_TYPE_ENTRY);
 872                 create_unknown_syscall_event(event_enabler, SC_TYPE_COMPAT_ENTRY);
 873         }
 874
 875         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
 876                 lttng_syscall_event_enabler_create_matching_events(&event_notifier_enabler->parent,
 877                         sc_exit_table.table, sc_exit_table.len, NULL, SC_TYPE_EXIT);
 878                 lttng_syscall_event_enabler_create_matching_events(&event_notifier_enabler->parent,
 879                         compat_sc_exit_table.table, compat_sc_exit_table.len, NULL, SC_TYPE_COMPAT_EXIT);
 880                 create_unknown_syscall_event(event_enabler, SC_TYPE_EXIT);
 881                 create_unknown_syscall_event(event_enabler, SC_TYPE_COMPAT_EXIT);
 882         }
 883         return ret;
 884 }
 885
 886 int lttng_syscalls_unregister_syscall_table(struct lttng_kernel_syscall_table *syscall_table)
 887 {
 888         int ret;
 889
 890         if (!syscall_table->syscall_dispatch)
 891                 return 0;
 892         if (syscall_table->sys_enter_registered) {
 893                 ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter",
 894                                 (void *) syscall_entry_event_probe, syscall_table);
 895                 if (ret)
 896                         return ret;
 897                 syscall_table->sys_enter_registered = 0;
 898         }
 899         if (syscall_table->sys_exit_registered) {
 900                 ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit",
 901                                 (void *) syscall_exit_event_probe, syscall_table);
 902                 if (ret)
 903                         return ret;
 904                 syscall_table->sys_exit_registered = 0;
 905         }
 906         return 0;
 907 }
 908
 909 int lttng_syscalls_destroy_syscall_table(struct lttng_kernel_syscall_table *syscall_table)
 910 {
 911         kfree(syscall_table->syscall_dispatch);
 912         kfree(syscall_table->syscall_exit_dispatch);
 913 #ifdef CONFIG_COMPAT
 914         kfree(syscall_table->compat_syscall_dispatch);
 915         kfree(syscall_table->compat_syscall_exit_dispatch);
 916 #endif
 917         kfree(syscall_table->sc_filter);
 918         return 0;
 919 }
 920
 921 static
 922 int get_syscall_nr(const char *syscall_name)
 923 {
 924         int syscall_nr = -1;
 925         int i;
 926
 927         for (i = 0; i < sc_table.len; i++) {
 928                 const struct trace_syscall_entry *entry;
 929                 const char *it_name;
 930
 931                 entry = &sc_table.table[i];
 932                 if (!entry->desc)
 933                         continue;
 934                 it_name = entry->desc->event_name;
 935                 it_name += strlen(SYSCALL_ENTRY_STR);
 936                 if (!strcmp(syscall_name, it_name)) {
 937                         syscall_nr = i;
 938                         break;
 939                 }
 940         }
 941         return syscall_nr;
 942 }
 943
 944 static
 945 int get_compat_syscall_nr(const char *syscall_name)
 946 {
 947         int syscall_nr = -1;
 948         int i;
 949
 950         for (i = 0; i < compat_sc_table.len; i++) {
 951                 const struct trace_syscall_entry *entry;
 952                 const char *it_name;
 953
 954                 entry = &compat_sc_table.table[i];
 955                 if (!entry->desc)
 956                         continue;
 957                 it_name = entry->desc->event_name;
 958                 it_name += strlen(COMPAT_SYSCALL_ENTRY_STR);
 959                 if (!strcmp(syscall_name, it_name)) {
 960                         syscall_nr = i;
 961                         break;
 962                 }
 963         }
 964         return syscall_nr;
 965 }
 966
 967 static
 968 uint32_t get_sc_tables_len(void)
 969 {
 970         return sc_table.len + compat_sc_table.len;
 971 }
 972
 973 static
 974 const char *get_syscall_name(const char *desc_name,
 975                 enum lttng_syscall_abi abi,
 976                 enum lttng_syscall_entryexit entryexit)
 977 {
 978         size_t prefix_len = 0;
 979
 980
 981         switch (entryexit) {
 982         case LTTNG_SYSCALL_ENTRY:
 983                 switch (abi) {
 984                 case LTTNG_SYSCALL_ABI_NATIVE:
 985                         prefix_len = strlen(SYSCALL_ENTRY_STR);
 986                         break;
 987                 case LTTNG_SYSCALL_ABI_COMPAT:
 988                         prefix_len = strlen(COMPAT_SYSCALL_ENTRY_STR);
 989                         break;
 990                 }
 991                 break;
 992         case LTTNG_SYSCALL_EXIT:
 993                 switch (abi) {
 994                 case LTTNG_SYSCALL_ABI_NATIVE:
 995                         prefix_len = strlen(SYSCALL_EXIT_STR);
 996                         break;
 997                 case LTTNG_SYSCALL_ABI_COMPAT:
 998                         prefix_len = strlen(COMPAT_SYSCALL_EXIT_STR);
 999                         break;
1000                 }
1001                 break;
1002         }
1003         WARN_ON_ONCE(prefix_len == 0);
1004         return desc_name + prefix_len;
1005 }
1006
1007 static
1008 int lttng_syscall_filter_enable(
1009                 struct lttng_syscall_filter *filter,
1010                 const char *desc_name, enum lttng_syscall_abi abi,
1011                 enum lttng_syscall_entryexit entryexit)
1012 {
1013         const char *syscall_name;
1014         unsigned long *bitmap;
1015         int syscall_nr;
1016
1017         syscall_name = get_syscall_name(desc_name, abi, entryexit);
1018
1019         switch (abi) {
1020         case LTTNG_SYSCALL_ABI_NATIVE:
1021                 syscall_nr = get_syscall_nr(syscall_name);
1022                 break;
1023         case LTTNG_SYSCALL_ABI_COMPAT:
1024                 syscall_nr = get_compat_syscall_nr(syscall_name);
1025                 break;
1026         default:
1027                 return -EINVAL;
1028         }
1029         if (syscall_nr < 0)
1030                 return -ENOENT;
1031
1032         switch (entryexit) {
1033         case LTTNG_SYSCALL_ENTRY:
1034                 switch (abi) {
1035                 case LTTNG_SYSCALL_ABI_NATIVE:
1036                         bitmap = filter->sc_entry;
1037                         break;
1038                 case LTTNG_SYSCALL_ABI_COMPAT:
1039                         bitmap = filter->sc_compat_entry;
1040                         break;
1041                 default:
1042                         return -EINVAL;
1043                 }
1044                 break;
1045         case LTTNG_SYSCALL_EXIT:
1046                 switch (abi) {
1047                 case LTTNG_SYSCALL_ABI_NATIVE:
1048                         bitmap = filter->sc_exit;
1049                         break;
1050                 case LTTNG_SYSCALL_ABI_COMPAT:
1051                         bitmap = filter->sc_compat_exit;
1052                         break;
1053                 default:
1054                         return -EINVAL;
1055                 }
1056                 break;
1057         default:
1058                 return -EINVAL;
1059         }
1060         if (test_bit(syscall_nr, bitmap))
1061                 return -EEXIST;
1062         bitmap_set(bitmap, syscall_nr, 1);
1063         return 0;
1064 }
1065
1066 int lttng_syscall_filter_enable_event(struct lttng_kernel_event_common *event)
1067 {
1068         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event);
1069         int ret;
1070
1071         WARN_ON_ONCE(event->priv->instrumentation != LTTNG_KERNEL_ABI_SYSCALL);
1072
1073         ret = lttng_syscall_filter_enable(syscall_table->sc_filter,
1074                 event->priv->desc->event_name, event->priv->u.syscall.abi,
1075                 event->priv->u.syscall.entryexit);
1076         if (ret)
1077                 return ret;
1078
1079         switch (event->type) {
1080         case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1081                 break;
1082         case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1083         {
1084                 unsigned int syscall_id = event->priv->u.syscall.syscall_id;
1085                 struct hlist_head *dispatch_list;
1086
1087                 switch (event->priv->u.syscall.entryexit) {
1088                 case LTTNG_SYSCALL_ENTRY:
1089                         switch (event->priv->u.syscall.abi) {
1090                         case LTTNG_SYSCALL_ABI_NATIVE:
1091                                 dispatch_list = &syscall_table->syscall_dispatch[syscall_id];
1092                                 break;
1093                         case LTTNG_SYSCALL_ABI_COMPAT:
1094                                 dispatch_list = &syscall_table->compat_syscall_dispatch[syscall_id];
1095                                 break;
1096                         default:
1097                                 ret = -EINVAL;
1098                                 goto end;
1099                         }
1100                         break;
1101                 case LTTNG_SYSCALL_EXIT:
1102                         switch (event->priv->u.syscall.abi) {
1103                         case LTTNG_SYSCALL_ABI_NATIVE:
1104                                 dispatch_list = &syscall_table->syscall_exit_dispatch[syscall_id];
1105                                 break;
1106                         case LTTNG_SYSCALL_ABI_COMPAT:
1107                                 dispatch_list = &syscall_table->compat_syscall_exit_dispatch[syscall_id];
1108                                 break;
1109                         default:
1110                                 ret = -EINVAL;
1111                                 goto end;
1112                         }
1113                         break;
1114                 default:
1115                         ret = -EINVAL;
1116                         goto end;
1117                 }
1118
1119                 hlist_add_head_rcu(&event->priv->u.syscall.node, dispatch_list);
1120                 break;
1121         }
1122         default:
1123                 WARN_ON_ONCE(1);
1124                 return -ENOSYS;
1125         }
1126 end:
1127         return ret;
1128 }
1129
1130 static
1131 int lttng_syscall_filter_disable(struct lttng_syscall_filter *filter,
1132                 const char *desc_name, enum lttng_syscall_abi abi,
1133                 enum lttng_syscall_entryexit entryexit)
1134 {
1135         const char *syscall_name;
1136         unsigned long *bitmap;
1137         int syscall_nr;
1138
1139         syscall_name = get_syscall_name(desc_name, abi, entryexit);
1140
1141         switch (abi) {
1142         case LTTNG_SYSCALL_ABI_NATIVE:
1143                 syscall_nr = get_syscall_nr(syscall_name);
1144                 break;
1145         case LTTNG_SYSCALL_ABI_COMPAT:
1146                 syscall_nr = get_compat_syscall_nr(syscall_name);
1147                 break;
1148         default:
1149                 return -EINVAL;
1150         }
1151         if (syscall_nr < 0)
1152                 return -ENOENT;
1153
1154         switch (entryexit) {
1155         case LTTNG_SYSCALL_ENTRY:
1156                 switch (abi) {
1157                 case LTTNG_SYSCALL_ABI_NATIVE:
1158                         bitmap = filter->sc_entry;
1159                         break;
1160                 case LTTNG_SYSCALL_ABI_COMPAT:
1161                         bitmap = filter->sc_compat_entry;
1162                         break;
1163                 default:
1164                         return -EINVAL;
1165                 }
1166                 break;
1167         case LTTNG_SYSCALL_EXIT:
1168                 switch (abi) {
1169                 case LTTNG_SYSCALL_ABI_NATIVE:
1170                         bitmap = filter->sc_exit;
1171                         break;
1172                 case LTTNG_SYSCALL_ABI_COMPAT:
1173                         bitmap = filter->sc_compat_exit;
1174                         break;
1175                 default:
1176                         return -EINVAL;
1177                 }
1178                 break;
1179         default:
1180                 return -EINVAL;
1181         }
1182         if (!test_bit(syscall_nr, bitmap))
1183                 return -EEXIST;
1184         bitmap_clear(bitmap, syscall_nr, 1);
1185
1186         return 0;
1187 }
1188
1189 int lttng_syscall_filter_disable_event(struct lttng_kernel_event_common *event)
1190 {
1191         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event);
1192         int ret;
1193
1194         ret = lttng_syscall_filter_disable(syscall_table->sc_filter,
1195                 event->priv->desc->event_name, event->priv->u.syscall.abi,
1196                 event->priv->u.syscall.entryexit);
1197         if (ret)
1198                 return ret;
1199
1200         switch (event->type) {
1201         case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1202                 break;
1203         case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1204         {
1205                 hlist_del_rcu(&event->priv->u.syscall.node);
1206                 break;
1207         }
1208         default:
1209                 WARN_ON_ONCE(1);
1210                 return -ENOSYS;
1211         }
1212         return 0;
1213 }
1214
1215 void lttng_syscall_table_set_wildcard_all(struct lttng_event_enabler_common *event_enabler)
1216 {
1217         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(event_enabler);
1218         enum lttng_kernel_abi_syscall_entryexit entryexit;
1219         int enabled = event_enabler->enabled;
1220
1221         if (!lttng_syscall_event_enabler_is_wildcard_all(event_enabler))
1222                 return;
1223         entryexit = event_enabler->event_param.u.syscall.entryexit;
1224         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
1225                 WRITE_ONCE(syscall_table->syscall_all_entry, enabled);
1226
1227         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
1228                 WRITE_ONCE(syscall_table->syscall_all_exit, enabled);
1229 }
1230
1231 static
1232 const struct trace_syscall_entry *syscall_list_get_entry(loff_t *pos)
1233 {
1234         const struct trace_syscall_entry *entry;
1235         int iter = 0;
1236
1237         for (entry = sc_table.table;
1238                         entry < sc_table.table + sc_table.len;
1239                          entry++) {
1240                 if (iter++ >= *pos)
1241                         return entry;
1242         }
1243         for (entry = compat_sc_table.table;
1244                         entry < compat_sc_table.table + compat_sc_table.len;
1245                          entry++) {
1246                 if (iter++ >= *pos)
1247                         return entry;
1248         }
1249         /* End of list */
1250         return NULL;
1251 }
1252
1253 static
1254 void *syscall_list_start(struct seq_file *m, loff_t *pos)
1255 {
1256         return (void *) syscall_list_get_entry(pos);
1257 }
1258
1259 static
1260 void *syscall_list_next(struct seq_file *m, void *p, loff_t *ppos)
1261 {
1262         (*ppos)++;
1263         return (void *) syscall_list_get_entry(ppos);
1264 }
1265
1266 static
1267 void syscall_list_stop(struct seq_file *m, void *p)
1268 {
1269 }
1270
1271 static
1272 int get_sc_table(const struct trace_syscall_entry *entry,
1273                 const struct trace_syscall_entry **table,
1274                 unsigned int *bitness)
1275 {
1276         if (entry >= sc_table.table && entry < sc_table.table + sc_table.len) {
1277                 if (bitness)
1278                         *bitness = BITS_PER_LONG;
1279                 if (table)
1280                         *table = sc_table.table;
1281                 return 0;
1282         }
1283         if (!(entry >= compat_sc_table.table
1284                         && entry < compat_sc_table.table + compat_sc_table.len)) {
1285                 return -EINVAL;
1286         }
1287         if (bitness)
1288                 *bitness = 32;
1289         if (table)
1290                 *table = compat_sc_table.table;
1291         return 0;
1292 }
1293
1294 static
1295 int syscall_list_show(struct seq_file *m, void *p)
1296 {
1297         const struct trace_syscall_entry *table, *entry = p;
1298         unsigned int bitness;
1299         unsigned long index;
1300         int ret;
1301         const char *name;
1302
1303         ret = get_sc_table(entry, &table, &bitness);
1304         if (ret)
1305                 return ret;
1306         if (!entry->desc)
1307                 return 0;
1308         if (table == sc_table.table) {
1309                 index = entry - table;
1310                 name = &entry->desc->event_name[strlen(SYSCALL_ENTRY_STR)];
1311         } else {
1312                 index = (entry - table) + sc_table.len;
1313                 name = &entry->desc->event_name[strlen(COMPAT_SYSCALL_ENTRY_STR)];
1314         }
1315         seq_printf(m,   "syscall { index = %lu; name = %s; bitness = %u; };\n",
1316                 index, name, bitness);
1317         return 0;
1318 }
1319
1320 static
1321 const struct seq_operations lttng_syscall_list_seq_ops = {
1322         .start = syscall_list_start,
1323         .next = syscall_list_next,
1324         .stop = syscall_list_stop,
1325         .show = syscall_list_show,
1326 };
1327
1328 static
1329 int lttng_syscall_list_open(struct inode *inode, struct file *file)
1330 {
1331         return seq_open(file, &lttng_syscall_list_seq_ops);
1332 }
1333
1334 const struct file_operations lttng_syscall_list_fops = {
1335         .owner = THIS_MODULE,
1336         .open = lttng_syscall_list_open,
1337         .read = seq_read,
1338         .llseek = seq_lseek,
1339         .release = seq_release,
1340 };
1341
1342 /*
1343  * A syscall is enabled if it is traced for either entry or exit.
1344  */
1345 long lttng_syscall_table_get_active_mask(struct lttng_kernel_syscall_table *syscall_table,
1346                 struct lttng_kernel_abi_syscall_mask __user *usyscall_mask)
1347 {
1348         uint32_t len, sc_tables_len, bitmask_len;
1349         int ret = 0, bit;
1350         char *tmp_mask;
1351         struct lttng_syscall_filter *filter;
1352
1353         ret = get_user(len, &usyscall_mask->len);
1354         if (ret)
1355                 return ret;
1356         sc_tables_len = get_sc_tables_len();
1357         bitmask_len = ALIGN(sc_tables_len, 8) >> 3;
1358         if (len < sc_tables_len) {
1359                 return put_user(sc_tables_len, &usyscall_mask->len);
1360         }
1361         /* Array is large enough, we can copy array to user-space. */
1362         tmp_mask = kzalloc(bitmask_len, GFP_KERNEL);
1363         if (!tmp_mask)
1364                 return -ENOMEM;
1365         filter = syscall_table->sc_filter;
1366
1367         for (bit = 0; bit < sc_table.len; bit++) {
1368                 char state;
1369
1370                 if (syscall_table->syscall_dispatch) {
1371                         if (!(READ_ONCE(syscall_table->syscall_all_entry)
1372                                         || READ_ONCE(syscall_table->syscall_all_exit)) && filter)
1373                                 state = test_bit(bit, filter->sc_entry)
1374                                         || test_bit(bit, filter->sc_exit);
1375                         else
1376                                 state = 1;
1377                 } else {
1378                         state = 0;
1379                 }
1380                 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1381         }
1382         for (; bit < sc_tables_len; bit++) {
1383                 char state;
1384
1385                 if (syscall_table->compat_syscall_dispatch) {
1386                         if (!(READ_ONCE(syscall_table->syscall_all_entry)
1387                                         || READ_ONCE(syscall_table->syscall_all_exit)) && filter)
1388                                 state = test_bit(bit - sc_table.len,
1389                                                 filter->sc_compat_entry)
1390                                         || test_bit(bit - sc_table.len,
1391                                                 filter->sc_compat_exit);
1392                         else
1393                                 state = 1;
1394                 } else {
1395                         state = 0;
1396                 }
1397                 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1398         }
1399         if (copy_to_user(usyscall_mask->mask, tmp_mask, bitmask_len))
1400                 ret = -EFAULT;
1401         kfree(tmp_mask);
1402         return ret;
1403 }
1404
1405 int lttng_abi_syscall_list(void)
1406 {
1407         struct file *syscall_list_file;
1408         int file_fd, ret;
1409
1410         file_fd = lttng_get_unused_fd();
1411         if (file_fd < 0) {
1412                 ret = file_fd;
1413                 goto fd_error;
1414         }
1415
1416         syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
1417                                           &lttng_syscall_list_fops,
1418                                           NULL, O_RDWR);
1419         if (IS_ERR(syscall_list_file)) {
1420                 ret = PTR_ERR(syscall_list_file);
1421                 goto file_error;
1422         }
1423         ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
1424         if (ret < 0)
1425                 goto open_error;
1426         fd_install(file_fd, syscall_list_file);
1427         return file_fd;
1428
1429 open_error:
1430         fput(syscall_list_file);
1431 file_error:
1432         put_unused_fd(file_fd);
1433 fd_error:
1434         return ret;
1435 }