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 /*
 640  * noinline to diminish caller stack size.
 641  * Should be called with sessions lock held.
 642  */
 643 static
 644 int lttng_create_syscall_event_if_missing(const struct trace_syscall_entry *table, size_t table_len,
 645         struct hlist_head *dispatch_table, struct lttng_event_recorder_enabler *syscall_event_enabler,
 646         enum sc_type type)
 647 {
 648         struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&syscall_event_enabler->parent);
 649         unsigned int i;
 650
 651         /* Allocate events for each syscall matching enabler, insert into table */
 652         for (i = 0; i < table_len; i++) {
 653                 const struct lttng_kernel_event_desc *desc = table[i].desc;
 654                 struct lttng_kernel_event_common_private *event_priv;
 655                 struct hlist_head *head;
 656                 bool found = false;
 657
 658                 if (!desc) {
 659                         /* Unknown syscall */
 660                         continue;
 661                 }
 662                 if (!lttng_desc_match_enabler(desc,
 663                                 lttng_event_recorder_enabler_as_enabler(syscall_event_enabler)))
 664                         continue;
 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->parent, desc, event_priv->pub))
 671                                 found = true;
 672                 }
 673                 if (found)
 674                         continue;
 675
 676                 lttng_syscall_event_enabler_create_event(&syscall_event_enabler->parent, desc, dispatch_table, type, i);
 677         }
 678         return 0;
 679 }
 680
 681 static
 682 int lttng_syscalls_populate_events(struct lttng_event_enabler_common *syscall_event_enabler)
 683 {
 684         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(syscall_event_enabler);
 685         struct lttng_event_recorder_enabler *event_recorder_enabler;
 686         struct lttng_kernel_channel_buffer *chan;
 687         struct lttng_kernel_abi_event ev;
 688         int ret;
 689
 690         if (syscall_event_enabler->enabler_type != LTTNG_EVENT_ENABLER_TYPE_RECORDER)
 691                 return 0;
 692         event_recorder_enabler = container_of(syscall_event_enabler, struct lttng_event_recorder_enabler, parent);
 693         chan = event_recorder_enabler->chan;
 694
 695         if (hlist_empty(&syscall_table->unknown_syscall_dispatch)) {
 696                 const struct lttng_kernel_event_desc *desc =
 697                         &__event_desc___syscall_entry_unknown;
 698                 struct lttng_kernel_event_common *event;
 699                 struct lttng_event_recorder_enabler *event_enabler;
 700
 701                 memset(&ev, 0, sizeof(ev));
 702                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 703                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 704                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 705                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 706                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 707                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 708                 if (!event_enabler) {
 709                         return -ENOMEM;
 710                 }
 711                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 712                 lttng_event_enabler_destroy(&event_enabler->parent);
 713                 WARN_ON_ONCE(!event);
 714                 if (IS_ERR(event)) {
 715                         return PTR_ERR(event);
 716                 }
 717                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->unknown_syscall_dispatch);
 718         }
 719
 720         if (hlist_empty(&syscall_table->compat_unknown_syscall_dispatch)) {
 721                 const struct lttng_kernel_event_desc *desc =
 722                         &__event_desc___compat_syscall_entry_unknown;
 723                 struct lttng_kernel_event_common *event;
 724                 struct lttng_event_recorder_enabler *event_enabler;
 725
 726                 memset(&ev, 0, sizeof(ev));
 727                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 728                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 729                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 730                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 731                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 732                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 733                 if (!event_enabler) {
 734                         return -ENOMEM;
 735                 }
 736                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 737                 WARN_ON_ONCE(!event);
 738                 lttng_event_enabler_destroy(&event_enabler->parent);
 739                 if (IS_ERR(event)) {
 740                         return PTR_ERR(event);
 741                 }
 742                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->compat_unknown_syscall_dispatch);
 743         }
 744
 745         if (hlist_empty(&syscall_table->compat_unknown_syscall_exit_dispatch)) {
 746                 const struct lttng_kernel_event_desc *desc =
 747                         &__event_desc___compat_syscall_exit_unknown;
 748                 struct lttng_kernel_event_common *event;
 749                 struct lttng_event_recorder_enabler *event_enabler;
 750
 751                 memset(&ev, 0, sizeof(ev));
 752                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 753                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 754                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 755                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 756                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 757                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 758                 if (!event_enabler) {
 759                         return -ENOMEM;
 760                 }
 761                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 762                 WARN_ON_ONCE(!event);
 763                 lttng_event_enabler_destroy(&event_enabler->parent);
 764                 if (IS_ERR(event)) {
 765                         return PTR_ERR(event);
 766                 }
 767                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->compat_unknown_syscall_exit_dispatch);
 768         }
 769
 770         if (hlist_empty(&syscall_table->unknown_syscall_exit_dispatch)) {
 771                 const struct lttng_kernel_event_desc *desc =
 772                         &__event_desc___syscall_exit_unknown;
 773                 struct lttng_kernel_event_common *event;
 774                 struct lttng_event_recorder_enabler *event_enabler;
 775
 776                 memset(&ev, 0, sizeof(ev));
 777                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 778                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 779                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 780                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 781                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 782                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 783                 if (!event_enabler) {
 784                         return -ENOMEM;
 785                 }
 786                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 787                 WARN_ON_ONCE(!event);
 788                 lttng_event_enabler_destroy(&event_enabler->parent);
 789                 if (IS_ERR(event)) {
 790                         return PTR_ERR(event);
 791                 }
 792                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->unknown_syscall_exit_dispatch);
 793         }
 794
 795         ret = lttng_create_syscall_event_if_missing(sc_table.table, sc_table.len,
 796                         syscall_table->syscall_dispatch, event_recorder_enabler, SC_TYPE_ENTRY);
 797         if (ret)
 798                 return ret;
 799         ret = lttng_create_syscall_event_if_missing(sc_exit_table.table, sc_exit_table.len,
 800                         syscall_table->syscall_exit_dispatch, event_recorder_enabler, SC_TYPE_EXIT);
 801         if (ret)
 802                 return ret;
 803
 804 #ifdef CONFIG_COMPAT
 805         ret = lttng_create_syscall_event_if_missing(compat_sc_table.table, compat_sc_table.len,
 806                         syscall_table->compat_syscall_dispatch, event_recorder_enabler, SC_TYPE_COMPAT_ENTRY);
 807         if (ret)
 808                 return ret;
 809         ret = lttng_create_syscall_event_if_missing(compat_sc_exit_table.table, compat_sc_exit_table.len,
 810                         syscall_table->compat_syscall_exit_dispatch, event_recorder_enabler, SC_TYPE_COMPAT_EXIT);
 811         if (ret)
 812                 return ret;
 813 #endif
 814         return ret;
 815 }
 816
 817 /*
 818  * Should be called with sessions lock held.
 819  */
 820 int lttng_event_enabler_create_syscall_events_if_missing(struct lttng_event_enabler_common *syscall_event_enabler)
 821 {
 822         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(syscall_event_enabler);
 823         int ret;
 824
 825         if (!syscall_table->syscall_dispatch) {
 826                 /* create syscall table mapping syscall to events */
 827                 syscall_table->syscall_dispatch = kzalloc(sizeof(struct hlist_head) * sc_table.len, GFP_KERNEL);
 828                 if (!syscall_table->syscall_dispatch)
 829                         return -ENOMEM;
 830         }
 831         if (!syscall_table->syscall_exit_dispatch) {
 832                 /* create syscall table mapping syscall to events */
 833                 syscall_table->syscall_exit_dispatch = kzalloc(sizeof(struct hlist_head) * sc_exit_table.len, GFP_KERNEL);
 834                 if (!syscall_table->syscall_exit_dispatch)
 835                         return -ENOMEM;
 836         }
 837
 838
 839 #ifdef CONFIG_COMPAT
 840         if (!syscall_table->compat_syscall_dispatch) {
 841                 /* create syscall table mapping compat syscall to events */
 842                 syscall_table->compat_syscall_dispatch = kzalloc(sizeof(struct hlist_head) * compat_sc_table.len, GFP_KERNEL);
 843                 if (!syscall_table->compat_syscall_dispatch)
 844                         return -ENOMEM;
 845         }
 846
 847         if (!syscall_table->compat_syscall_exit_dispatch) {
 848                 /* create syscall table mapping compat syscall to events */
 849                 syscall_table->compat_syscall_exit_dispatch = kzalloc(sizeof(struct hlist_head) * compat_sc_exit_table.len, GFP_KERNEL);
 850                 if (!syscall_table->compat_syscall_exit_dispatch)
 851                         return -ENOMEM;
 852         }
 853 #endif
 854         if (!syscall_table->sc_filter) {
 855                 syscall_table->sc_filter = kzalloc(sizeof(struct lttng_syscall_filter),
 856                                 GFP_KERNEL);
 857                 if (!syscall_table->sc_filter)
 858                         return -ENOMEM;
 859         }
 860
 861         ret = lttng_syscalls_populate_events(syscall_event_enabler);
 862         if (ret)
 863                 return ret;
 864
 865         ret = lttng_syscalls_create_matching_event_notifiers(syscall_event_enabler);
 866         if (ret)
 867                 return ret;
 868
 869         if (!syscall_table->sys_enter_registered) {
 870                 ret = lttng_wrapper_tracepoint_probe_register("sys_enter",
 871                                 (void *) syscall_entry_event_probe, syscall_table);
 872                 if (ret)
 873                         return ret;
 874                 syscall_table->sys_enter_registered = 1;
 875         }
 876         if (!syscall_table->sys_exit_registered) {
 877                 ret = lttng_wrapper_tracepoint_probe_register("sys_exit",
 878                                 (void *) syscall_exit_event_probe, syscall_table);
 879                 if (ret) {
 880                         WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter",
 881                                 (void *) syscall_entry_event_probe, syscall_table));
 882                         return ret;
 883                 }
 884                 syscall_table->sys_exit_registered = 1;
 885         }
 886
 887         return ret;
 888 }
 889
 890 static
 891 void create_unknown_event_notifier(
 892                 struct lttng_event_notifier_enabler *event_notifier_enabler,
 893                 enum sc_type type)
 894 {
 895         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(&event_notifier_enabler->parent);
 896         struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&event_notifier_enabler->parent);
 897         struct lttng_kernel_event_common_private *event_priv;
 898         const struct lttng_kernel_event_desc *desc;
 899         struct hlist_head *unknown_dispatch_list;
 900         bool found = false;
 901         struct hlist_head *head;
 902
 903         switch (type) {
 904         case SC_TYPE_ENTRY:
 905                 desc = &__event_desc___syscall_entry_unknown;
 906                 unknown_dispatch_list = &syscall_table->unknown_syscall_dispatch;
 907                 break;
 908         case SC_TYPE_EXIT:
 909                 desc = &__event_desc___syscall_exit_unknown;
 910                 unknown_dispatch_list = &syscall_table->unknown_syscall_exit_dispatch;
 911                 break;
 912         case SC_TYPE_COMPAT_ENTRY:
 913                 desc = &__event_desc___compat_syscall_entry_unknown;
 914                 unknown_dispatch_list = &syscall_table->compat_unknown_syscall_dispatch;
 915                 break;
 916         case SC_TYPE_COMPAT_EXIT:
 917                 desc = &__event_desc___compat_syscall_exit_unknown;
 918                 unknown_dispatch_list = &syscall_table->compat_unknown_syscall_exit_dispatch;
 919                 break;
 920         default:
 921                 WARN_ON_ONCE(1);
 922         }
 923
 924         /*
 925          * Check if already created.
 926          */
 927         head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
 928         lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
 929                 if (lttng_event_enabler_desc_match_event(&event_notifier_enabler->parent, desc, event_priv->pub))
 930                         found = true;
 931         }
 932         if (!found)
 933                 lttng_syscall_event_enabler_create_event(&event_notifier_enabler->parent, desc, unknown_dispatch_list, type, -1U);
 934 }
 935
 936 static
 937 void create_matching_event_notifiers(
 938                 struct lttng_event_notifier_enabler *syscall_event_notifier_enabler,
 939                 const struct trace_syscall_entry *table,
 940                 size_t table_len, enum sc_type type)
 941 {
 942         struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&syscall_event_notifier_enabler->parent);
 943         const struct lttng_kernel_event_desc *desc;
 944         unsigned int i;
 945
 946         /* iterate over all syscall and create event_notifier that match */
 947         for (i = 0; i < table_len; i++) {
 948                 struct lttng_kernel_event_common_private *event_priv;
 949                 struct hlist_head *head;
 950                 int found = 0;
 951
 952                 desc = table[i].desc;
 953                 if (!desc) {
 954                         /* Unknown syscall */
 955                         continue;
 956                 }
 957
 958                 if (!lttng_desc_match_enabler(desc,
 959                                 lttng_event_notifier_enabler_as_enabler(syscall_event_notifier_enabler)))
 960                         continue;
 961
 962                 /*
 963                  * Check if already created.
 964                  */
 965                 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
 966                 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
 967                         if (lttng_event_enabler_desc_match_event(&syscall_event_notifier_enabler->parent, desc, event_priv->pub))
 968                                 found = 1;
 969                 }
 970                 if (found)
 971                         continue;
 972
 973                 lttng_syscall_event_enabler_create_event(&syscall_event_notifier_enabler->parent, desc, NULL, type, i);
 974         }
 975 }
 976
 977 static
 978 int lttng_syscalls_create_matching_event_notifiers(struct lttng_event_enabler_common *event_enabler)
 979 {
 980         int ret;
 981         enum lttng_kernel_abi_syscall_entryexit entryexit =
 982                         event_enabler->event_param.u.syscall.entryexit;
 983         struct lttng_event_notifier_enabler *event_notifier_enabler;
 984
 985         if (event_enabler->enabler_type != LTTNG_EVENT_ENABLER_TYPE_NOTIFIER)
 986                 return 0;
 987         event_notifier_enabler = container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
 988
 989         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
 990                 create_matching_event_notifiers(event_notifier_enabler,
 991                         sc_table.table, sc_table.len, SC_TYPE_ENTRY);
 992                 create_matching_event_notifiers(event_notifier_enabler,
 993                         compat_sc_table.table, compat_sc_table.len,
 994                         SC_TYPE_COMPAT_ENTRY);
 995                 create_unknown_event_notifier(event_notifier_enabler, SC_TYPE_ENTRY);
 996                 create_unknown_event_notifier(event_notifier_enabler, SC_TYPE_COMPAT_ENTRY);
 997         }
 998
 999         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
1000                 create_matching_event_notifiers(event_notifier_enabler,
1001                         sc_exit_table.table, sc_exit_table.len,
1002                         SC_TYPE_EXIT);
1003                 create_matching_event_notifiers(event_notifier_enabler,
1004                         compat_sc_exit_table.table, compat_sc_exit_table.len,
1005                         SC_TYPE_COMPAT_EXIT);
1006                 create_unknown_event_notifier(event_notifier_enabler, SC_TYPE_EXIT);
1007                 create_unknown_event_notifier(event_notifier_enabler, SC_TYPE_COMPAT_EXIT);
1008         }
1009         return ret;
1010 }
1011
1012 int lttng_syscalls_unregister_syscall_table(struct lttng_kernel_syscall_table *syscall_table)
1013 {
1014         int ret;
1015
1016         if (!syscall_table->syscall_dispatch)
1017                 return 0;
1018         if (syscall_table->sys_enter_registered) {
1019                 ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter",
1020                                 (void *) syscall_entry_event_probe, syscall_table);
1021                 if (ret)
1022                         return ret;
1023                 syscall_table->sys_enter_registered = 0;
1024         }
1025         if (syscall_table->sys_exit_registered) {
1026                 ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit",
1027                                 (void *) syscall_exit_event_probe, syscall_table);
1028                 if (ret)
1029                         return ret;
1030                 syscall_table->sys_exit_registered = 0;
1031         }
1032         return 0;
1033 }
1034
1035 int lttng_syscalls_destroy_syscall_table(struct lttng_kernel_syscall_table *syscall_table)
1036 {
1037         kfree(syscall_table->syscall_dispatch);
1038         kfree(syscall_table->syscall_exit_dispatch);
1039 #ifdef CONFIG_COMPAT
1040         kfree(syscall_table->compat_syscall_dispatch);
1041         kfree(syscall_table->compat_syscall_exit_dispatch);
1042 #endif
1043         kfree(syscall_table->sc_filter);
1044         return 0;
1045 }
1046
1047 static
1048 int get_syscall_nr(const char *syscall_name)
1049 {
1050         int syscall_nr = -1;
1051         int i;
1052
1053         for (i = 0; i < sc_table.len; i++) {
1054                 const struct trace_syscall_entry *entry;
1055                 const char *it_name;
1056
1057                 entry = &sc_table.table[i];
1058                 if (!entry->desc)
1059                         continue;
1060                 it_name = entry->desc->event_name;
1061                 it_name += strlen(SYSCALL_ENTRY_STR);
1062                 if (!strcmp(syscall_name, it_name)) {
1063                         syscall_nr = i;
1064                         break;
1065                 }
1066         }
1067         return syscall_nr;
1068 }
1069
1070 static
1071 int get_compat_syscall_nr(const char *syscall_name)
1072 {
1073         int syscall_nr = -1;
1074         int i;
1075
1076         for (i = 0; i < compat_sc_table.len; i++) {
1077                 const struct trace_syscall_entry *entry;
1078                 const char *it_name;
1079
1080                 entry = &compat_sc_table.table[i];
1081                 if (!entry->desc)
1082                         continue;
1083                 it_name = entry->desc->event_name;
1084                 it_name += strlen(COMPAT_SYSCALL_ENTRY_STR);
1085                 if (!strcmp(syscall_name, it_name)) {
1086                         syscall_nr = i;
1087                         break;
1088                 }
1089         }
1090         return syscall_nr;
1091 }
1092
1093 static
1094 uint32_t get_sc_tables_len(void)
1095 {
1096         return sc_table.len + compat_sc_table.len;
1097 }
1098
1099 static
1100 const char *get_syscall_name(const char *desc_name,
1101                 enum lttng_syscall_abi abi,
1102                 enum lttng_syscall_entryexit entryexit)
1103 {
1104         size_t prefix_len = 0;
1105
1106
1107         switch (entryexit) {
1108         case LTTNG_SYSCALL_ENTRY:
1109                 switch (abi) {
1110                 case LTTNG_SYSCALL_ABI_NATIVE:
1111                         prefix_len = strlen(SYSCALL_ENTRY_STR);
1112                         break;
1113                 case LTTNG_SYSCALL_ABI_COMPAT:
1114                         prefix_len = strlen(COMPAT_SYSCALL_ENTRY_STR);
1115                         break;
1116                 }
1117                 break;
1118         case LTTNG_SYSCALL_EXIT:
1119                 switch (abi) {
1120                 case LTTNG_SYSCALL_ABI_NATIVE:
1121                         prefix_len = strlen(SYSCALL_EXIT_STR);
1122                         break;
1123                 case LTTNG_SYSCALL_ABI_COMPAT:
1124                         prefix_len = strlen(COMPAT_SYSCALL_EXIT_STR);
1125                         break;
1126                 }
1127                 break;
1128         }
1129         WARN_ON_ONCE(prefix_len == 0);
1130         return desc_name + prefix_len;
1131 }
1132
1133 static
1134 int lttng_syscall_filter_enable(
1135                 struct lttng_syscall_filter *filter,
1136                 const char *desc_name, enum lttng_syscall_abi abi,
1137                 enum lttng_syscall_entryexit entryexit)
1138 {
1139         const char *syscall_name;
1140         unsigned long *bitmap;
1141         int syscall_nr;
1142
1143         syscall_name = get_syscall_name(desc_name, abi, entryexit);
1144
1145         switch (abi) {
1146         case LTTNG_SYSCALL_ABI_NATIVE:
1147                 syscall_nr = get_syscall_nr(syscall_name);
1148                 break;
1149         case LTTNG_SYSCALL_ABI_COMPAT:
1150                 syscall_nr = get_compat_syscall_nr(syscall_name);
1151                 break;
1152         default:
1153                 return -EINVAL;
1154         }
1155         if (syscall_nr < 0)
1156                 return -ENOENT;
1157
1158         switch (entryexit) {
1159         case LTTNG_SYSCALL_ENTRY:
1160                 switch (abi) {
1161                 case LTTNG_SYSCALL_ABI_NATIVE:
1162                         bitmap = filter->sc_entry;
1163                         break;
1164                 case LTTNG_SYSCALL_ABI_COMPAT:
1165                         bitmap = filter->sc_compat_entry;
1166                         break;
1167                 default:
1168                         return -EINVAL;
1169                 }
1170                 break;
1171         case LTTNG_SYSCALL_EXIT:
1172                 switch (abi) {
1173                 case LTTNG_SYSCALL_ABI_NATIVE:
1174                         bitmap = filter->sc_exit;
1175                         break;
1176                 case LTTNG_SYSCALL_ABI_COMPAT:
1177                         bitmap = filter->sc_compat_exit;
1178                         break;
1179                 default:
1180                         return -EINVAL;
1181                 }
1182                 break;
1183         default:
1184                 return -EINVAL;
1185         }
1186         if (test_bit(syscall_nr, bitmap))
1187                 return -EEXIST;
1188         bitmap_set(bitmap, syscall_nr, 1);
1189         return 0;
1190 }
1191
1192 int lttng_syscall_filter_enable_event(struct lttng_kernel_event_common *event)
1193 {
1194         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event);
1195         int ret;
1196
1197         WARN_ON_ONCE(event->priv->instrumentation != LTTNG_KERNEL_ABI_SYSCALL);
1198
1199         ret = lttng_syscall_filter_enable(syscall_table->sc_filter,
1200                 event->priv->desc->event_name, event->priv->u.syscall.abi,
1201                 event->priv->u.syscall.entryexit);
1202         if (ret)
1203                 return ret;
1204
1205         switch (event->type) {
1206         case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1207                 break;
1208         case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1209         {
1210                 unsigned int syscall_id = event->priv->u.syscall.syscall_id;
1211                 struct hlist_head *dispatch_list;
1212
1213                 switch (event->priv->u.syscall.entryexit) {
1214                 case LTTNG_SYSCALL_ENTRY:
1215                         switch (event->priv->u.syscall.abi) {
1216                         case LTTNG_SYSCALL_ABI_NATIVE:
1217                                 dispatch_list = &syscall_table->syscall_dispatch[syscall_id];
1218                                 break;
1219                         case LTTNG_SYSCALL_ABI_COMPAT:
1220                                 dispatch_list = &syscall_table->compat_syscall_dispatch[syscall_id];
1221                                 break;
1222                         default:
1223                                 ret = -EINVAL;
1224                                 goto end;
1225                         }
1226                         break;
1227                 case LTTNG_SYSCALL_EXIT:
1228                         switch (event->priv->u.syscall.abi) {
1229                         case LTTNG_SYSCALL_ABI_NATIVE:
1230                                 dispatch_list = &syscall_table->syscall_exit_dispatch[syscall_id];
1231                                 break;
1232                         case LTTNG_SYSCALL_ABI_COMPAT:
1233                                 dispatch_list = &syscall_table->compat_syscall_exit_dispatch[syscall_id];
1234                                 break;
1235                         default:
1236                                 ret = -EINVAL;
1237                                 goto end;
1238                         }
1239                         break;
1240                 default:
1241                         ret = -EINVAL;
1242                         goto end;
1243                 }
1244
1245                 hlist_add_head_rcu(&event->priv->u.syscall.node, dispatch_list);
1246                 break;
1247         }
1248         default:
1249                 WARN_ON_ONCE(1);
1250                 return -ENOSYS;
1251         }
1252 end:
1253         return ret;
1254 }
1255
1256 static
1257 int lttng_syscall_filter_disable(struct lttng_syscall_filter *filter,
1258                 const char *desc_name, enum lttng_syscall_abi abi,
1259                 enum lttng_syscall_entryexit entryexit)
1260 {
1261         const char *syscall_name;
1262         unsigned long *bitmap;
1263         int syscall_nr;
1264
1265         syscall_name = get_syscall_name(desc_name, abi, entryexit);
1266
1267         switch (abi) {
1268         case LTTNG_SYSCALL_ABI_NATIVE:
1269                 syscall_nr = get_syscall_nr(syscall_name);
1270                 break;
1271         case LTTNG_SYSCALL_ABI_COMPAT:
1272                 syscall_nr = get_compat_syscall_nr(syscall_name);
1273                 break;
1274         default:
1275                 return -EINVAL;
1276         }
1277         if (syscall_nr < 0)
1278                 return -ENOENT;
1279
1280         switch (entryexit) {
1281         case LTTNG_SYSCALL_ENTRY:
1282                 switch (abi) {
1283                 case LTTNG_SYSCALL_ABI_NATIVE:
1284                         bitmap = filter->sc_entry;
1285                         break;
1286                 case LTTNG_SYSCALL_ABI_COMPAT:
1287                         bitmap = filter->sc_compat_entry;
1288                         break;
1289                 default:
1290                         return -EINVAL;
1291                 }
1292                 break;
1293         case LTTNG_SYSCALL_EXIT:
1294                 switch (abi) {
1295                 case LTTNG_SYSCALL_ABI_NATIVE:
1296                         bitmap = filter->sc_exit;
1297                         break;
1298                 case LTTNG_SYSCALL_ABI_COMPAT:
1299                         bitmap = filter->sc_compat_exit;
1300                         break;
1301                 default:
1302                         return -EINVAL;
1303                 }
1304                 break;
1305         default:
1306                 return -EINVAL;
1307         }
1308         if (!test_bit(syscall_nr, bitmap))
1309                 return -EEXIST;
1310         bitmap_clear(bitmap, syscall_nr, 1);
1311
1312         return 0;
1313 }
1314
1315 int lttng_syscall_filter_disable_event(struct lttng_kernel_event_common *event)
1316 {
1317         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event);
1318         int ret;
1319
1320         ret = lttng_syscall_filter_disable(syscall_table->sc_filter,
1321                 event->priv->desc->event_name, event->priv->u.syscall.abi,
1322                 event->priv->u.syscall.entryexit);
1323         if (ret)
1324                 return ret;
1325
1326         switch (event->type) {
1327         case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1328                 break;
1329         case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1330         {
1331                 hlist_del_rcu(&event->priv->u.syscall.node);
1332                 break;
1333         }
1334         default:
1335                 WARN_ON_ONCE(1);
1336                 return -ENOSYS;
1337         }
1338         return 0;
1339 }
1340
1341 void lttng_syscall_table_set_wildcard_all(struct lttng_event_enabler_common *event_enabler)
1342 {
1343         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(event_enabler);
1344         enum lttng_kernel_abi_syscall_entryexit entryexit;
1345         int enabled = event_enabler->enabled;
1346
1347         if (event_enabler->event_param.instrumentation != LTTNG_KERNEL_ABI_SYSCALL)
1348                 return;
1349         if (event_enabler->event_param.u.syscall.abi != LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL)
1350                 return;
1351         if (event_enabler->event_param.u.syscall.match != LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME)
1352                 return;
1353         if (strcmp(event_enabler->event_param.name, "*"))
1354                 return;
1355
1356         entryexit = event_enabler->event_param.u.syscall.entryexit;
1357         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
1358                 WRITE_ONCE(syscall_table->syscall_all_entry, enabled);
1359
1360         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
1361                 WRITE_ONCE(syscall_table->syscall_all_exit, enabled);
1362 }
1363
1364 static
1365 const struct trace_syscall_entry *syscall_list_get_entry(loff_t *pos)
1366 {
1367         const struct trace_syscall_entry *entry;
1368         int iter = 0;
1369
1370         for (entry = sc_table.table;
1371                         entry < sc_table.table + sc_table.len;
1372                          entry++) {
1373                 if (iter++ >= *pos)
1374                         return entry;
1375         }
1376         for (entry = compat_sc_table.table;
1377                         entry < compat_sc_table.table + compat_sc_table.len;
1378                          entry++) {
1379                 if (iter++ >= *pos)
1380                         return entry;
1381         }
1382         /* End of list */
1383         return NULL;
1384 }
1385
1386 static
1387 void *syscall_list_start(struct seq_file *m, loff_t *pos)
1388 {
1389         return (void *) syscall_list_get_entry(pos);
1390 }
1391
1392 static
1393 void *syscall_list_next(struct seq_file *m, void *p, loff_t *ppos)
1394 {
1395         (*ppos)++;
1396         return (void *) syscall_list_get_entry(ppos);
1397 }
1398
1399 static
1400 void syscall_list_stop(struct seq_file *m, void *p)
1401 {
1402 }
1403
1404 static
1405 int get_sc_table(const struct trace_syscall_entry *entry,
1406                 const struct trace_syscall_entry **table,
1407                 unsigned int *bitness)
1408 {
1409         if (entry >= sc_table.table && entry < sc_table.table + sc_table.len) {
1410                 if (bitness)
1411                         *bitness = BITS_PER_LONG;
1412                 if (table)
1413                         *table = sc_table.table;
1414                 return 0;
1415         }
1416         if (!(entry >= compat_sc_table.table
1417                         && entry < compat_sc_table.table + compat_sc_table.len)) {
1418                 return -EINVAL;
1419         }
1420         if (bitness)
1421                 *bitness = 32;
1422         if (table)
1423                 *table = compat_sc_table.table;
1424         return 0;
1425 }
1426
1427 static
1428 int syscall_list_show(struct seq_file *m, void *p)
1429 {
1430         const struct trace_syscall_entry *table, *entry = p;
1431         unsigned int bitness;
1432         unsigned long index;
1433         int ret;
1434         const char *name;
1435
1436         ret = get_sc_table(entry, &table, &bitness);
1437         if (ret)
1438                 return ret;
1439         if (!entry->desc)
1440                 return 0;
1441         if (table == sc_table.table) {
1442                 index = entry - table;
1443                 name = &entry->desc->event_name[strlen(SYSCALL_ENTRY_STR)];
1444         } else {
1445                 index = (entry - table) + sc_table.len;
1446                 name = &entry->desc->event_name[strlen(COMPAT_SYSCALL_ENTRY_STR)];
1447         }
1448         seq_printf(m,   "syscall { index = %lu; name = %s; bitness = %u; };\n",
1449                 index, name, bitness);
1450         return 0;
1451 }
1452
1453 static
1454 const struct seq_operations lttng_syscall_list_seq_ops = {
1455         .start = syscall_list_start,
1456         .next = syscall_list_next,
1457         .stop = syscall_list_stop,
1458         .show = syscall_list_show,
1459 };
1460
1461 static
1462 int lttng_syscall_list_open(struct inode *inode, struct file *file)
1463 {
1464         return seq_open(file, &lttng_syscall_list_seq_ops);
1465 }
1466
1467 const struct file_operations lttng_syscall_list_fops = {
1468         .owner = THIS_MODULE,
1469         .open = lttng_syscall_list_open,
1470         .read = seq_read,
1471         .llseek = seq_lseek,
1472         .release = seq_release,
1473 };
1474
1475 /*
1476  * A syscall is enabled if it is traced for either entry or exit.
1477  */
1478 long lttng_syscall_table_get_active_mask(struct lttng_kernel_syscall_table *syscall_table,
1479                 struct lttng_kernel_abi_syscall_mask __user *usyscall_mask)
1480 {
1481         uint32_t len, sc_tables_len, bitmask_len;
1482         int ret = 0, bit;
1483         char *tmp_mask;
1484         struct lttng_syscall_filter *filter;
1485
1486         ret = get_user(len, &usyscall_mask->len);
1487         if (ret)
1488                 return ret;
1489         sc_tables_len = get_sc_tables_len();
1490         bitmask_len = ALIGN(sc_tables_len, 8) >> 3;
1491         if (len < sc_tables_len) {
1492                 return put_user(sc_tables_len, &usyscall_mask->len);
1493         }
1494         /* Array is large enough, we can copy array to user-space. */
1495         tmp_mask = kzalloc(bitmask_len, GFP_KERNEL);
1496         if (!tmp_mask)
1497                 return -ENOMEM;
1498         filter = syscall_table->sc_filter;
1499
1500         for (bit = 0; bit < sc_table.len; bit++) {
1501                 char state;
1502
1503                 if (syscall_table->syscall_dispatch) {
1504                         if (!(READ_ONCE(syscall_table->syscall_all_entry)
1505                                         || READ_ONCE(syscall_table->syscall_all_exit)) && filter)
1506                                 state = test_bit(bit, filter->sc_entry)
1507                                         || test_bit(bit, filter->sc_exit);
1508                         else
1509                                 state = 1;
1510                 } else {
1511                         state = 0;
1512                 }
1513                 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1514         }
1515         for (; bit < sc_tables_len; bit++) {
1516                 char state;
1517
1518                 if (syscall_table->compat_syscall_dispatch) {
1519                         if (!(READ_ONCE(syscall_table->syscall_all_entry)
1520                                         || READ_ONCE(syscall_table->syscall_all_exit)) && filter)
1521                                 state = test_bit(bit - sc_table.len,
1522                                                 filter->sc_compat_entry)
1523                                         || test_bit(bit - sc_table.len,
1524                                                 filter->sc_compat_exit);
1525                         else
1526                                 state = 1;
1527                 } else {
1528                         state = 0;
1529                 }
1530                 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1531         }
1532         if (copy_to_user(usyscall_mask->mask, tmp_mask, bitmask_len))
1533                 ret = -EFAULT;
1534         kfree(tmp_mask);
1535         return ret;
1536 }
1537
1538 int lttng_abi_syscall_list(void)
1539 {
1540         struct file *syscall_list_file;
1541         int file_fd, ret;
1542
1543         file_fd = lttng_get_unused_fd();
1544         if (file_fd < 0) {
1545                 ret = file_fd;
1546                 goto fd_error;
1547         }
1548
1549         syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
1550                                           &lttng_syscall_list_fops,
1551                                           NULL, O_RDWR);
1552         if (IS_ERR(syscall_list_file)) {
1553                 ret = PTR_ERR(syscall_list_file);
1554                 goto file_error;
1555         }
1556         ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
1557         if (ret < 0)
1558                 goto open_error;
1559         fd_install(file_fd, syscall_list_file);
1560         return file_fd;
1561
1562 open_error:
1563         fput(syscall_list_file);
1564 file_error:
1565         put_unused_fd(file_fd);
1566 fd_error:
1567         return ret;
1568 }