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                 break;
 631         }
 632         default:
 633                 break;
 634         }
 635 }
 636
 637 /*
 638  * noinline to diminish caller stack size.
 639  * Should be called with sessions lock held.
 640  */
 641 static
 642 int lttng_create_syscall_event_if_missing(const struct trace_syscall_entry *table, size_t table_len,
 643         struct hlist_head *dispatch_table, struct lttng_event_recorder_enabler *syscall_event_enabler,
 644         enum sc_type type)
 645 {
 646         struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&syscall_event_enabler->parent);
 647         unsigned int i;
 648
 649         /* Allocate events for each syscall matching enabler, insert into table */
 650         for (i = 0; i < table_len; i++) {
 651                 const struct lttng_kernel_event_desc *desc = table[i].desc;
 652                 struct lttng_kernel_event_common_private *event_priv;
 653                 struct hlist_head *head;
 654                 bool found = false;
 655
 656                 if (!desc) {
 657                         /* Unknown syscall */
 658                         continue;
 659                 }
 660                 if (!lttng_desc_match_enabler(desc,
 661                                 lttng_event_recorder_enabler_as_enabler(syscall_event_enabler)))
 662                         continue;
 663                 /*
 664                  * Check if already created.
 665                  */
 666                 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
 667                 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
 668                         if (lttng_event_enabler_desc_match_event(&syscall_event_enabler->parent, desc, event_priv->pub))
 669                                 found = true;
 670                 }
 671                 if (found)
 672                         continue;
 673
 674                 lttng_syscall_event_enabler_create_event(&syscall_event_enabler->parent, desc, dispatch_table, type, i);
 675         }
 676         return 0;
 677 }
 678
 679 static
 680 int lttng_syscalls_populate_events(struct lttng_event_enabler_common *syscall_event_enabler)
 681 {
 682         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(syscall_event_enabler);
 683         struct lttng_event_recorder_enabler *event_recorder_enabler;
 684         struct lttng_kernel_channel_buffer *chan;
 685         struct lttng_kernel_abi_event ev;
 686         int ret;
 687
 688         if (syscall_event_enabler->enabler_type != LTTNG_EVENT_ENABLER_TYPE_RECORDER)
 689                 return 0;
 690         event_recorder_enabler = container_of(syscall_event_enabler, struct lttng_event_recorder_enabler, parent);
 691         chan = event_recorder_enabler->chan;
 692
 693         if (hlist_empty(&syscall_table->unknown_syscall_dispatch)) {
 694                 const struct lttng_kernel_event_desc *desc =
 695                         &__event_desc___syscall_entry_unknown;
 696                 struct lttng_kernel_event_common *event;
 697                 struct lttng_event_recorder_enabler *event_enabler;
 698
 699                 memset(&ev, 0, sizeof(ev));
 700                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 701                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 702                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 703                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 704                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 705                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 706                 if (!event_enabler) {
 707                         return -ENOMEM;
 708                 }
 709                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 710                 lttng_event_enabler_destroy(&event_enabler->parent);
 711                 WARN_ON_ONCE(!event);
 712                 if (IS_ERR(event)) {
 713                         return PTR_ERR(event);
 714                 }
 715                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->unknown_syscall_dispatch);
 716         }
 717
 718         if (hlist_empty(&syscall_table->compat_unknown_syscall_dispatch)) {
 719                 const struct lttng_kernel_event_desc *desc =
 720                         &__event_desc___compat_syscall_entry_unknown;
 721                 struct lttng_kernel_event_common *event;
 722                 struct lttng_event_recorder_enabler *event_enabler;
 723
 724                 memset(&ev, 0, sizeof(ev));
 725                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 726                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 727                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 728                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 729                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 730                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 731                 if (!event_enabler) {
 732                         return -ENOMEM;
 733                 }
 734                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 735                 WARN_ON_ONCE(!event);
 736                 lttng_event_enabler_destroy(&event_enabler->parent);
 737                 if (IS_ERR(event)) {
 738                         return PTR_ERR(event);
 739                 }
 740                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->compat_unknown_syscall_dispatch);
 741         }
 742
 743         if (hlist_empty(&syscall_table->compat_unknown_syscall_exit_dispatch)) {
 744                 const struct lttng_kernel_event_desc *desc =
 745                         &__event_desc___compat_syscall_exit_unknown;
 746                 struct lttng_kernel_event_common *event;
 747                 struct lttng_event_recorder_enabler *event_enabler;
 748
 749                 memset(&ev, 0, sizeof(ev));
 750                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 751                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 752                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 753                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 754                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 755                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 756                 if (!event_enabler) {
 757                         return -ENOMEM;
 758                 }
 759                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 760                 WARN_ON_ONCE(!event);
 761                 lttng_event_enabler_destroy(&event_enabler->parent);
 762                 if (IS_ERR(event)) {
 763                         return PTR_ERR(event);
 764                 }
 765                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->compat_unknown_syscall_exit_dispatch);
 766         }
 767
 768         if (hlist_empty(&syscall_table->unknown_syscall_exit_dispatch)) {
 769                 const struct lttng_kernel_event_desc *desc =
 770                         &__event_desc___syscall_exit_unknown;
 771                 struct lttng_kernel_event_common *event;
 772                 struct lttng_event_recorder_enabler *event_enabler;
 773
 774                 memset(&ev, 0, sizeof(ev));
 775                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 776                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 777                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 778                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 779                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 780                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 781                 if (!event_enabler) {
 782                         return -ENOMEM;
 783                 }
 784                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 785                 WARN_ON_ONCE(!event);
 786                 lttng_event_enabler_destroy(&event_enabler->parent);
 787                 if (IS_ERR(event)) {
 788                         return PTR_ERR(event);
 789                 }
 790                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->unknown_syscall_exit_dispatch);
 791         }
 792
 793         ret = lttng_create_syscall_event_if_missing(sc_table.table, sc_table.len,
 794                         syscall_table->syscall_dispatch, event_recorder_enabler, SC_TYPE_ENTRY);
 795         if (ret)
 796                 return ret;
 797         ret = lttng_create_syscall_event_if_missing(sc_exit_table.table, sc_exit_table.len,
 798                         syscall_table->syscall_exit_dispatch, event_recorder_enabler, SC_TYPE_EXIT);
 799         if (ret)
 800                 return ret;
 801
 802 #ifdef CONFIG_COMPAT
 803         ret = lttng_create_syscall_event_if_missing(compat_sc_table.table, compat_sc_table.len,
 804                         syscall_table->compat_syscall_dispatch, event_recorder_enabler, SC_TYPE_COMPAT_ENTRY);
 805         if (ret)
 806                 return ret;
 807         ret = lttng_create_syscall_event_if_missing(compat_sc_exit_table.table, compat_sc_exit_table.len,
 808                         syscall_table->compat_syscall_exit_dispatch, event_recorder_enabler, SC_TYPE_COMPAT_EXIT);
 809         if (ret)
 810                 return ret;
 811 #endif
 812         return ret;
 813 }
 814
 815 /*
 816  * Should be called with sessions lock held.
 817  */
 818 int lttng_event_enabler_create_syscall_events_if_missing(struct lttng_event_enabler_common *syscall_event_enabler)
 819 {
 820         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(syscall_event_enabler);
 821         int ret;
 822
 823         if (!syscall_table->syscall_dispatch) {
 824                 /* create syscall table mapping syscall to events */
 825                 syscall_table->syscall_dispatch = kzalloc(sizeof(struct hlist_head) * sc_table.len, GFP_KERNEL);
 826                 if (!syscall_table->syscall_dispatch)
 827                         return -ENOMEM;
 828         }
 829         if (!syscall_table->syscall_exit_dispatch) {
 830                 /* create syscall table mapping syscall to events */
 831                 syscall_table->syscall_exit_dispatch = kzalloc(sizeof(struct hlist_head) * sc_exit_table.len, GFP_KERNEL);
 832                 if (!syscall_table->syscall_exit_dispatch)
 833                         return -ENOMEM;
 834         }
 835
 836
 837 #ifdef CONFIG_COMPAT
 838         if (!syscall_table->compat_syscall_dispatch) {
 839                 /* create syscall table mapping compat syscall to events */
 840                 syscall_table->compat_syscall_dispatch = kzalloc(sizeof(struct hlist_head) * compat_sc_table.len, GFP_KERNEL);
 841                 if (!syscall_table->compat_syscall_dispatch)
 842                         return -ENOMEM;
 843         }
 844
 845         if (!syscall_table->compat_syscall_exit_dispatch) {
 846                 /* create syscall table mapping compat syscall to events */
 847                 syscall_table->compat_syscall_exit_dispatch = kzalloc(sizeof(struct hlist_head) * compat_sc_exit_table.len, GFP_KERNEL);
 848                 if (!syscall_table->compat_syscall_exit_dispatch)
 849                         return -ENOMEM;
 850         }
 851 #endif
 852         if (!syscall_table->sc_filter) {
 853                 syscall_table->sc_filter = kzalloc(sizeof(struct lttng_syscall_filter),
 854                                 GFP_KERNEL);
 855                 if (!syscall_table->sc_filter)
 856                         return -ENOMEM;
 857         }
 858
 859         ret = lttng_syscalls_populate_events(syscall_event_enabler);
 860         if (ret)
 861                 return ret;
 862
 863         ret = lttng_syscalls_create_matching_event_notifiers(syscall_event_enabler);
 864         if (ret)
 865                 return ret;
 866
 867         if (!syscall_table->sys_enter_registered) {
 868                 ret = lttng_wrapper_tracepoint_probe_register("sys_enter",
 869                                 (void *) syscall_entry_event_probe, syscall_table);
 870                 if (ret)
 871                         return ret;
 872                 syscall_table->sys_enter_registered = 1;
 873         }
 874         if (!syscall_table->sys_exit_registered) {
 875                 ret = lttng_wrapper_tracepoint_probe_register("sys_exit",
 876                                 (void *) syscall_exit_event_probe, syscall_table);
 877                 if (ret) {
 878                         WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter",
 879                                 (void *) syscall_entry_event_probe, syscall_table));
 880                         return ret;
 881                 }
 882                 syscall_table->sys_exit_registered = 1;
 883         }
 884
 885         return ret;
 886 }
 887
 888 static
 889 void create_unknown_event_notifier(
 890                 struct lttng_event_notifier_enabler *event_notifier_enabler,
 891                 enum sc_type type)
 892 {
 893         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(&event_notifier_enabler->parent);
 894         struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&event_notifier_enabler->parent);
 895         struct lttng_kernel_event_common_private *event_priv;
 896         const struct lttng_kernel_event_desc *desc;
 897         struct hlist_head *unknown_dispatch_list;
 898         bool found = false;
 899         struct hlist_head *head;
 900
 901         switch (type) {
 902         case SC_TYPE_ENTRY:
 903                 desc = &__event_desc___syscall_entry_unknown;
 904                 unknown_dispatch_list = &syscall_table->unknown_syscall_dispatch;
 905                 break;
 906         case SC_TYPE_EXIT:
 907                 desc = &__event_desc___syscall_exit_unknown;
 908                 unknown_dispatch_list = &syscall_table->unknown_syscall_exit_dispatch;
 909                 break;
 910         case SC_TYPE_COMPAT_ENTRY:
 911                 desc = &__event_desc___compat_syscall_entry_unknown;
 912                 unknown_dispatch_list = &syscall_table->compat_unknown_syscall_dispatch;
 913                 break;
 914         case SC_TYPE_COMPAT_EXIT:
 915                 desc = &__event_desc___compat_syscall_exit_unknown;
 916                 unknown_dispatch_list = &syscall_table->compat_unknown_syscall_exit_dispatch;
 917                 break;
 918         default:
 919                 WARN_ON_ONCE(1);
 920         }
 921
 922         /*
 923          * Check if already created.
 924          */
 925         head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
 926         lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
 927                 if (lttng_event_enabler_desc_match_event(&event_notifier_enabler->parent, desc, event_priv->pub))
 928                         found = true;
 929         }
 930         if (!found)
 931                 lttng_syscall_event_enabler_create_event(&event_notifier_enabler->parent, desc, unknown_dispatch_list, type, -1U);
 932 }
 933
 934 static
 935 void create_matching_event_notifiers(
 936                 struct lttng_event_notifier_enabler *syscall_event_notifier_enabler,
 937                 const struct trace_syscall_entry *table,
 938                 size_t table_len, enum sc_type type)
 939 {
 940         struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&syscall_event_notifier_enabler->parent);
 941         const struct lttng_kernel_event_desc *desc;
 942         unsigned int i;
 943
 944         /* iterate over all syscall and create event_notifier that match */
 945         for (i = 0; i < table_len; i++) {
 946                 struct lttng_kernel_event_common_private *event_priv;
 947                 struct hlist_head *head;
 948                 int found = 0;
 949
 950                 desc = table[i].desc;
 951                 if (!desc) {
 952                         /* Unknown syscall */
 953                         continue;
 954                 }
 955
 956                 if (!lttng_desc_match_enabler(desc,
 957                                 lttng_event_notifier_enabler_as_enabler(syscall_event_notifier_enabler)))
 958                         continue;
 959
 960                 /*
 961                  * Check if already created.
 962                  */
 963                 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
 964                 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
 965                         if (lttng_event_enabler_desc_match_event(&syscall_event_notifier_enabler->parent, desc, event_priv->pub))
 966                                 found = 1;
 967                 }
 968                 if (found)
 969                         continue;
 970
 971                 lttng_syscall_event_enabler_create_event(&syscall_event_notifier_enabler->parent, desc, NULL, type, i);
 972         }
 973 }
 974
 975 static
 976 int lttng_syscalls_create_matching_event_notifiers(struct lttng_event_enabler_common *event_enabler)
 977 {
 978         int ret;
 979         enum lttng_kernel_abi_syscall_entryexit entryexit =
 980                         event_enabler->event_param.u.syscall.entryexit;
 981         struct lttng_event_notifier_enabler *event_notifier_enabler;
 982
 983         if (event_enabler->enabler_type != LTTNG_EVENT_ENABLER_TYPE_NOTIFIER)
 984                 return 0;
 985         event_notifier_enabler = container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
 986
 987         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
 988                 create_matching_event_notifiers(event_notifier_enabler,
 989                         sc_table.table, sc_table.len, SC_TYPE_ENTRY);
 990                 create_matching_event_notifiers(event_notifier_enabler,
 991                         compat_sc_table.table, compat_sc_table.len,
 992                         SC_TYPE_COMPAT_ENTRY);
 993                 create_unknown_event_notifier(event_notifier_enabler, SC_TYPE_ENTRY);
 994                 create_unknown_event_notifier(event_notifier_enabler, SC_TYPE_COMPAT_ENTRY);
 995         }
 996
 997         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
 998                 create_matching_event_notifiers(event_notifier_enabler,
 999                         sc_exit_table.table, sc_exit_table.len,
1000                         SC_TYPE_EXIT);
1001                 create_matching_event_notifiers(event_notifier_enabler,
1002                         compat_sc_exit_table.table, compat_sc_exit_table.len,
1003                         SC_TYPE_COMPAT_EXIT);
1004                 create_unknown_event_notifier(event_notifier_enabler, SC_TYPE_EXIT);
1005                 create_unknown_event_notifier(event_notifier_enabler, SC_TYPE_COMPAT_EXIT);
1006         }
1007         return ret;
1008 }
1009
1010 int lttng_syscalls_unregister_syscall_table(struct lttng_kernel_syscall_table *syscall_table)
1011 {
1012         int ret;
1013
1014         if (!syscall_table->syscall_dispatch)
1015                 return 0;
1016         if (syscall_table->sys_enter_registered) {
1017                 ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter",
1018                                 (void *) syscall_entry_event_probe, syscall_table);
1019                 if (ret)
1020                         return ret;
1021                 syscall_table->sys_enter_registered = 0;
1022         }
1023         if (syscall_table->sys_exit_registered) {
1024                 ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit",
1025                                 (void *) syscall_exit_event_probe, syscall_table);
1026                 if (ret)
1027                         return ret;
1028                 syscall_table->sys_exit_registered = 0;
1029         }
1030         return 0;
1031 }
1032
1033 int lttng_syscalls_destroy_syscall_table(struct lttng_kernel_syscall_table *syscall_table)
1034 {
1035         kfree(syscall_table->syscall_dispatch);
1036         kfree(syscall_table->syscall_exit_dispatch);
1037 #ifdef CONFIG_COMPAT
1038         kfree(syscall_table->compat_syscall_dispatch);
1039         kfree(syscall_table->compat_syscall_exit_dispatch);
1040 #endif
1041         kfree(syscall_table->sc_filter);
1042         return 0;
1043 }
1044
1045 static
1046 int get_syscall_nr(const char *syscall_name)
1047 {
1048         int syscall_nr = -1;
1049         int i;
1050
1051         for (i = 0; i < sc_table.len; i++) {
1052                 const struct trace_syscall_entry *entry;
1053                 const char *it_name;
1054
1055                 entry = &sc_table.table[i];
1056                 if (!entry->desc)
1057                         continue;
1058                 it_name = entry->desc->event_name;
1059                 it_name += strlen(SYSCALL_ENTRY_STR);
1060                 if (!strcmp(syscall_name, it_name)) {
1061                         syscall_nr = i;
1062                         break;
1063                 }
1064         }
1065         return syscall_nr;
1066 }
1067
1068 static
1069 int get_compat_syscall_nr(const char *syscall_name)
1070 {
1071         int syscall_nr = -1;
1072         int i;
1073
1074         for (i = 0; i < compat_sc_table.len; i++) {
1075                 const struct trace_syscall_entry *entry;
1076                 const char *it_name;
1077
1078                 entry = &compat_sc_table.table[i];
1079                 if (!entry->desc)
1080                         continue;
1081                 it_name = entry->desc->event_name;
1082                 it_name += strlen(COMPAT_SYSCALL_ENTRY_STR);
1083                 if (!strcmp(syscall_name, it_name)) {
1084                         syscall_nr = i;
1085                         break;
1086                 }
1087         }
1088         return syscall_nr;
1089 }
1090
1091 static
1092 uint32_t get_sc_tables_len(void)
1093 {
1094         return sc_table.len + compat_sc_table.len;
1095 }
1096
1097 static
1098 const char *get_syscall_name(const char *desc_name,
1099                 enum lttng_syscall_abi abi,
1100                 enum lttng_syscall_entryexit entryexit)
1101 {
1102         size_t prefix_len = 0;
1103
1104
1105         switch (entryexit) {
1106         case LTTNG_SYSCALL_ENTRY:
1107                 switch (abi) {
1108                 case LTTNG_SYSCALL_ABI_NATIVE:
1109                         prefix_len = strlen(SYSCALL_ENTRY_STR);
1110                         break;
1111                 case LTTNG_SYSCALL_ABI_COMPAT:
1112                         prefix_len = strlen(COMPAT_SYSCALL_ENTRY_STR);
1113                         break;
1114                 }
1115                 break;
1116         case LTTNG_SYSCALL_EXIT:
1117                 switch (abi) {
1118                 case LTTNG_SYSCALL_ABI_NATIVE:
1119                         prefix_len = strlen(SYSCALL_EXIT_STR);
1120                         break;
1121                 case LTTNG_SYSCALL_ABI_COMPAT:
1122                         prefix_len = strlen(COMPAT_SYSCALL_EXIT_STR);
1123                         break;
1124                 }
1125                 break;
1126         }
1127         WARN_ON_ONCE(prefix_len == 0);
1128         return desc_name + prefix_len;
1129 }
1130
1131 static
1132 int lttng_syscall_filter_enable(
1133                 struct lttng_syscall_filter *filter,
1134                 const char *desc_name, enum lttng_syscall_abi abi,
1135                 enum lttng_syscall_entryexit entryexit)
1136 {
1137         const char *syscall_name;
1138         unsigned long *bitmap;
1139         int syscall_nr;
1140
1141         syscall_name = get_syscall_name(desc_name, abi, entryexit);
1142
1143         switch (abi) {
1144         case LTTNG_SYSCALL_ABI_NATIVE:
1145                 syscall_nr = get_syscall_nr(syscall_name);
1146                 break;
1147         case LTTNG_SYSCALL_ABI_COMPAT:
1148                 syscall_nr = get_compat_syscall_nr(syscall_name);
1149                 break;
1150         default:
1151                 return -EINVAL;
1152         }
1153         if (syscall_nr < 0)
1154                 return -ENOENT;
1155
1156         switch (entryexit) {
1157         case LTTNG_SYSCALL_ENTRY:
1158                 switch (abi) {
1159                 case LTTNG_SYSCALL_ABI_NATIVE:
1160                         bitmap = filter->sc_entry;
1161                         break;
1162                 case LTTNG_SYSCALL_ABI_COMPAT:
1163                         bitmap = filter->sc_compat_entry;
1164                         break;
1165                 default:
1166                         return -EINVAL;
1167                 }
1168                 break;
1169         case LTTNG_SYSCALL_EXIT:
1170                 switch (abi) {
1171                 case LTTNG_SYSCALL_ABI_NATIVE:
1172                         bitmap = filter->sc_exit;
1173                         break;
1174                 case LTTNG_SYSCALL_ABI_COMPAT:
1175                         bitmap = filter->sc_compat_exit;
1176                         break;
1177                 default:
1178                         return -EINVAL;
1179                 }
1180                 break;
1181         default:
1182                 return -EINVAL;
1183         }
1184         if (test_bit(syscall_nr, bitmap))
1185                 return -EEXIST;
1186         bitmap_set(bitmap, syscall_nr, 1);
1187         return 0;
1188 }
1189
1190 int lttng_syscall_filter_enable_event(struct lttng_kernel_event_common *event)
1191 {
1192         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event);
1193         int ret;
1194
1195         WARN_ON_ONCE(event->priv->instrumentation != LTTNG_KERNEL_ABI_SYSCALL);
1196
1197         ret = lttng_syscall_filter_enable(syscall_table->sc_filter,
1198                 event->priv->desc->event_name, event->priv->u.syscall.abi,
1199                 event->priv->u.syscall.entryexit);
1200         if (ret)
1201                 return ret;
1202
1203         switch (event->type) {
1204         case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1205                 break;
1206         case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1207         {
1208                 unsigned int syscall_id = event->priv->u.syscall.syscall_id;
1209                 struct hlist_head *dispatch_list;
1210
1211                 switch (event->priv->u.syscall.entryexit) {
1212                 case LTTNG_SYSCALL_ENTRY:
1213                         switch (event->priv->u.syscall.abi) {
1214                         case LTTNG_SYSCALL_ABI_NATIVE:
1215                                 dispatch_list = &syscall_table->syscall_dispatch[syscall_id];
1216                                 break;
1217                         case LTTNG_SYSCALL_ABI_COMPAT:
1218                                 dispatch_list = &syscall_table->compat_syscall_dispatch[syscall_id];
1219                                 break;
1220                         default:
1221                                 ret = -EINVAL;
1222                                 goto end;
1223                         }
1224                         break;
1225                 case LTTNG_SYSCALL_EXIT:
1226                         switch (event->priv->u.syscall.abi) {
1227                         case LTTNG_SYSCALL_ABI_NATIVE:
1228                                 dispatch_list = &syscall_table->syscall_exit_dispatch[syscall_id];
1229                                 break;
1230                         case LTTNG_SYSCALL_ABI_COMPAT:
1231                                 dispatch_list = &syscall_table->compat_syscall_exit_dispatch[syscall_id];
1232                                 break;
1233                         default:
1234                                 ret = -EINVAL;
1235                                 goto end;
1236                         }
1237                         break;
1238                 default:
1239                         ret = -EINVAL;
1240                         goto end;
1241                 }
1242
1243                 hlist_add_head_rcu(&event->priv->u.syscall.node, dispatch_list);
1244                 break;
1245         }
1246         default:
1247                 WARN_ON_ONCE(1);
1248                 return -ENOSYS;
1249         }
1250 end:
1251         return ret;
1252 }
1253
1254 static
1255 int lttng_syscall_filter_disable(struct lttng_syscall_filter *filter,
1256                 const char *desc_name, enum lttng_syscall_abi abi,
1257                 enum lttng_syscall_entryexit entryexit)
1258 {
1259         const char *syscall_name;
1260         unsigned long *bitmap;
1261         int syscall_nr;
1262
1263         syscall_name = get_syscall_name(desc_name, abi, entryexit);
1264
1265         switch (abi) {
1266         case LTTNG_SYSCALL_ABI_NATIVE:
1267                 syscall_nr = get_syscall_nr(syscall_name);
1268                 break;
1269         case LTTNG_SYSCALL_ABI_COMPAT:
1270                 syscall_nr = get_compat_syscall_nr(syscall_name);
1271                 break;
1272         default:
1273                 return -EINVAL;
1274         }
1275         if (syscall_nr < 0)
1276                 return -ENOENT;
1277
1278         switch (entryexit) {
1279         case LTTNG_SYSCALL_ENTRY:
1280                 switch (abi) {
1281                 case LTTNG_SYSCALL_ABI_NATIVE:
1282                         bitmap = filter->sc_entry;
1283                         break;
1284                 case LTTNG_SYSCALL_ABI_COMPAT:
1285                         bitmap = filter->sc_compat_entry;
1286                         break;
1287                 default:
1288                         return -EINVAL;
1289                 }
1290                 break;
1291         case LTTNG_SYSCALL_EXIT:
1292                 switch (abi) {
1293                 case LTTNG_SYSCALL_ABI_NATIVE:
1294                         bitmap = filter->sc_exit;
1295                         break;
1296                 case LTTNG_SYSCALL_ABI_COMPAT:
1297                         bitmap = filter->sc_compat_exit;
1298                         break;
1299                 default:
1300                         return -EINVAL;
1301                 }
1302                 break;
1303         default:
1304                 return -EINVAL;
1305         }
1306         if (!test_bit(syscall_nr, bitmap))
1307                 return -EEXIST;
1308         bitmap_clear(bitmap, syscall_nr, 1);
1309
1310         return 0;
1311 }
1312
1313 int lttng_syscall_filter_disable_event(struct lttng_kernel_event_common *event)
1314 {
1315         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event);
1316         int ret;
1317
1318         ret = lttng_syscall_filter_disable(syscall_table->sc_filter,
1319                 event->priv->desc->event_name, event->priv->u.syscall.abi,
1320                 event->priv->u.syscall.entryexit);
1321         if (ret)
1322                 return ret;
1323
1324         switch (event->type) {
1325         case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1326                 break;
1327         case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1328         {
1329                 hlist_del_rcu(&event->priv->u.syscall.node);
1330                 break;
1331         }
1332         default:
1333                 WARN_ON_ONCE(1);
1334                 return -ENOSYS;
1335         }
1336         return 0;
1337 }
1338
1339 void lttng_syscall_table_set_wildcard_all(struct lttng_event_enabler_common *event_enabler)
1340 {
1341         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(event_enabler);
1342         enum lttng_kernel_abi_syscall_entryexit entryexit;
1343         int enabled = event_enabler->enabled;
1344
1345         if (event_enabler->event_param.instrumentation != LTTNG_KERNEL_ABI_SYSCALL)
1346                 return;
1347         if (event_enabler->event_param.u.syscall.abi != LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL)
1348                 return;
1349         if (event_enabler->event_param.u.syscall.match != LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME)
1350                 return;
1351         if (strcmp(event_enabler->event_param.name, "*"))
1352                 return;
1353
1354         entryexit = event_enabler->event_param.u.syscall.entryexit;
1355         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
1356                 WRITE_ONCE(syscall_table->syscall_all_entry, enabled);
1357
1358         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
1359                 WRITE_ONCE(syscall_table->syscall_all_exit, enabled);
1360 }
1361
1362 static
1363 const struct trace_syscall_entry *syscall_list_get_entry(loff_t *pos)
1364 {
1365         const struct trace_syscall_entry *entry;
1366         int iter = 0;
1367
1368         for (entry = sc_table.table;
1369                         entry < sc_table.table + sc_table.len;
1370                          entry++) {
1371                 if (iter++ >= *pos)
1372                         return entry;
1373         }
1374         for (entry = compat_sc_table.table;
1375                         entry < compat_sc_table.table + compat_sc_table.len;
1376                          entry++) {
1377                 if (iter++ >= *pos)
1378                         return entry;
1379         }
1380         /* End of list */
1381         return NULL;
1382 }
1383
1384 static
1385 void *syscall_list_start(struct seq_file *m, loff_t *pos)
1386 {
1387         return (void *) syscall_list_get_entry(pos);
1388 }
1389
1390 static
1391 void *syscall_list_next(struct seq_file *m, void *p, loff_t *ppos)
1392 {
1393         (*ppos)++;
1394         return (void *) syscall_list_get_entry(ppos);
1395 }
1396
1397 static
1398 void syscall_list_stop(struct seq_file *m, void *p)
1399 {
1400 }
1401
1402 static
1403 int get_sc_table(const struct trace_syscall_entry *entry,
1404                 const struct trace_syscall_entry **table,
1405                 unsigned int *bitness)
1406 {
1407         if (entry >= sc_table.table && entry < sc_table.table + sc_table.len) {
1408                 if (bitness)
1409                         *bitness = BITS_PER_LONG;
1410                 if (table)
1411                         *table = sc_table.table;
1412                 return 0;
1413         }
1414         if (!(entry >= compat_sc_table.table
1415                         && entry < compat_sc_table.table + compat_sc_table.len)) {
1416                 return -EINVAL;
1417         }
1418         if (bitness)
1419                 *bitness = 32;
1420         if (table)
1421                 *table = compat_sc_table.table;
1422         return 0;
1423 }
1424
1425 static
1426 int syscall_list_show(struct seq_file *m, void *p)
1427 {
1428         const struct trace_syscall_entry *table, *entry = p;
1429         unsigned int bitness;
1430         unsigned long index;
1431         int ret;
1432         const char *name;
1433
1434         ret = get_sc_table(entry, &table, &bitness);
1435         if (ret)
1436                 return ret;
1437         if (!entry->desc)
1438                 return 0;
1439         if (table == sc_table.table) {
1440                 index = entry - table;
1441                 name = &entry->desc->event_name[strlen(SYSCALL_ENTRY_STR)];
1442         } else {
1443                 index = (entry - table) + sc_table.len;
1444                 name = &entry->desc->event_name[strlen(COMPAT_SYSCALL_ENTRY_STR)];
1445         }
1446         seq_printf(m,   "syscall { index = %lu; name = %s; bitness = %u; };\n",
1447                 index, name, bitness);
1448         return 0;
1449 }
1450
1451 static
1452 const struct seq_operations lttng_syscall_list_seq_ops = {
1453         .start = syscall_list_start,
1454         .next = syscall_list_next,
1455         .stop = syscall_list_stop,
1456         .show = syscall_list_show,
1457 };
1458
1459 static
1460 int lttng_syscall_list_open(struct inode *inode, struct file *file)
1461 {
1462         return seq_open(file, &lttng_syscall_list_seq_ops);
1463 }
1464
1465 const struct file_operations lttng_syscall_list_fops = {
1466         .owner = THIS_MODULE,
1467         .open = lttng_syscall_list_open,
1468         .read = seq_read,
1469         .llseek = seq_lseek,
1470         .release = seq_release,
1471 };
1472
1473 /*
1474  * A syscall is enabled if it is traced for either entry or exit.
1475  */
1476 long lttng_syscall_table_get_active_mask(struct lttng_kernel_syscall_table *syscall_table,
1477                 struct lttng_kernel_abi_syscall_mask __user *usyscall_mask)
1478 {
1479         uint32_t len, sc_tables_len, bitmask_len;
1480         int ret = 0, bit;
1481         char *tmp_mask;
1482         struct lttng_syscall_filter *filter;
1483
1484         ret = get_user(len, &usyscall_mask->len);
1485         if (ret)
1486                 return ret;
1487         sc_tables_len = get_sc_tables_len();
1488         bitmask_len = ALIGN(sc_tables_len, 8) >> 3;
1489         if (len < sc_tables_len) {
1490                 return put_user(sc_tables_len, &usyscall_mask->len);
1491         }
1492         /* Array is large enough, we can copy array to user-space. */
1493         tmp_mask = kzalloc(bitmask_len, GFP_KERNEL);
1494         if (!tmp_mask)
1495                 return -ENOMEM;
1496         filter = syscall_table->sc_filter;
1497
1498         for (bit = 0; bit < sc_table.len; bit++) {
1499                 char state;
1500
1501                 if (syscall_table->syscall_dispatch) {
1502                         if (!(READ_ONCE(syscall_table->syscall_all_entry)
1503                                         || READ_ONCE(syscall_table->syscall_all_exit)) && filter)
1504                                 state = test_bit(bit, filter->sc_entry)
1505                                         || test_bit(bit, filter->sc_exit);
1506                         else
1507                                 state = 1;
1508                 } else {
1509                         state = 0;
1510                 }
1511                 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1512         }
1513         for (; bit < sc_tables_len; bit++) {
1514                 char state;
1515
1516                 if (syscall_table->compat_syscall_dispatch) {
1517                         if (!(READ_ONCE(syscall_table->syscall_all_entry)
1518                                         || READ_ONCE(syscall_table->syscall_all_exit)) && filter)
1519                                 state = test_bit(bit - sc_table.len,
1520                                                 filter->sc_compat_entry)
1521                                         || test_bit(bit - sc_table.len,
1522                                                 filter->sc_compat_exit);
1523                         else
1524                                 state = 1;
1525                 } else {
1526                         state = 0;
1527                 }
1528                 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1529         }
1530         if (copy_to_user(usyscall_mask->mask, tmp_mask, bitmask_len))
1531                 ret = -EFAULT;
1532         kfree(tmp_mask);
1533         return ret;
1534 }
1535
1536 int lttng_abi_syscall_list(void)
1537 {
1538         struct file *syscall_list_file;
1539         int file_fd, ret;
1540
1541         file_fd = lttng_get_unused_fd();
1542         if (file_fd < 0) {
1543                 ret = file_fd;
1544                 goto fd_error;
1545         }
1546
1547         syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
1548                                           &lttng_syscall_list_fops,
1549                                           NULL, O_RDWR);
1550         if (IS_ERR(syscall_list_file)) {
1551                 ret = PTR_ERR(syscall_list_file);
1552                 goto file_error;
1553         }
1554         ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
1555         if (ret < 0)
1556                 goto open_error;
1557         fd_install(file_fd, syscall_list_file);
1558         return file_fd;
1559
1560 open_error:
1561         fput(syscall_list_file);
1562 file_error:
1563         put_unused_fd(file_fd);
1564 fd_error:
1565         return ret;
1566 }