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