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 void syscall_entry_event_unknown(struct hlist_head *unknown_action_list_head,
 136         struct pt_regs *regs, long id)
 137 {
 138         unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 139         struct lttng_kernel_event_common_private *event_priv;
 140
 141         lttng_syscall_get_arguments(current, regs, args);
 142         lttng_hlist_for_each_entry_rcu(event_priv, unknown_action_list_head, u.syscall.node) {
 143                 if (unlikely(in_compat_syscall()))
 144                         __event_probe__compat_syscall_entry_unknown(event_priv->pub, id, args);
 145                 else
 146                         __event_probe__syscall_entry_unknown(event_priv->pub, id, args);
 147         }
 148 }
 149
 150 static __always_inline
 151 void syscall_entry_event_call_func(struct hlist_head *action_list,
 152                 void *func, unsigned int nrargs,
 153                 struct pt_regs *regs)
 154 {
 155         struct lttng_kernel_event_common_private *event_priv;
 156
 157         switch (nrargs) {
 158         case 0:
 159         {
 160                 void (*fptr)(void *__data) = func;
 161
 162                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 163                         fptr(event_priv->pub);
 164                 break;
 165         }
 166         case 1:
 167         {
 168                 void (*fptr)(void *__data, unsigned long arg0) = func;
 169                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 170
 171                 lttng_syscall_get_arguments(current, regs, args);
 172                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 173                         fptr(event_priv->pub, args[0]);
 174                 break;
 175         }
 176         case 2:
 177         {
 178                 void (*fptr)(void *__data,
 179                         unsigned long arg0,
 180                         unsigned long arg1) = func;
 181                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 182
 183                 lttng_syscall_get_arguments(current, regs, args);
 184                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 185                         fptr(event_priv->pub, args[0], args[1]);
 186                 break;
 187         }
 188         case 3:
 189         {
 190                 void (*fptr)(void *__data,
 191                         unsigned long arg0,
 192                         unsigned long arg1,
 193                         unsigned long arg2) = func;
 194                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 195
 196                 lttng_syscall_get_arguments(current, regs, args);
 197                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 198                         fptr(event_priv->pub, args[0], args[1], args[2]);
 199                 break;
 200         }
 201         case 4:
 202         {
 203                 void (*fptr)(void *__data,
 204                         unsigned long arg0,
 205                         unsigned long arg1,
 206                         unsigned long arg2,
 207                         unsigned long arg3) = func;
 208                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 209
 210                 lttng_syscall_get_arguments(current, regs, args);
 211                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 212                         fptr(event_priv->pub, args[0], args[1], args[2], args[3]);
 213                 break;
 214         }
 215         case 5:
 216         {
 217                 void (*fptr)(void *__data,
 218                         unsigned long arg0,
 219                         unsigned long arg1,
 220                         unsigned long arg2,
 221                         unsigned long arg3,
 222                         unsigned long arg4) = func;
 223                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 224
 225                 lttng_syscall_get_arguments(current, regs, args);
 226                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 227                         fptr(event_priv->pub, args[0], args[1], args[2], args[3], args[4]);
 228                 break;
 229         }
 230         case 6:
 231         {
 232                 void (*fptr)(void *__data,
 233                         unsigned long arg0,
 234                         unsigned long arg1,
 235                         unsigned long arg2,
 236                         unsigned long arg3,
 237                         unsigned long arg4,
 238                         unsigned long arg5) = func;
 239                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 240
 241                 lttng_syscall_get_arguments(current, regs, args);
 242                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 243                         fptr(event_priv->pub, args[0], args[1], args[2],
 244                              args[3], args[4], args[5]);
 245                 break;
 246         }
 247         default:
 248                 break;
 249         }
 250 }
 251
 252 void syscall_entry_event_probe(void *__data, struct pt_regs *regs, long id)
 253 {
 254         struct lttng_kernel_syscall_table *syscall_table = __data;
 255         struct hlist_head *action_list, *unknown_action_list;
 256         const struct trace_syscall_entry *table, *entry;
 257         size_t table_len;
 258
 259         if (unlikely(in_compat_syscall())) {
 260                 struct lttng_syscall_filter *filter = syscall_table->sc_filter;
 261
 262                 if (id < 0 || id >= NR_compat_syscalls
 263                         || (!READ_ONCE(syscall_table->syscall_all_entry) && !test_bit(id, filter->sc_compat_entry))) {
 264                         /* System call filtered out. */
 265                         return;
 266                 }
 267                 table = compat_sc_table.table;
 268                 table_len = compat_sc_table.len;
 269                 unknown_action_list = &syscall_table->compat_unknown_syscall_dispatch;
 270         } else {
 271                 struct lttng_syscall_filter *filter = syscall_table->sc_filter;
 272
 273                 if (id < 0 || id >= NR_syscalls
 274                         || (!READ_ONCE(syscall_table->syscall_all_entry) && !test_bit(id, filter->sc_entry))) {
 275                         /* System call filtered out. */
 276                         return;
 277                 }
 278                 table = sc_table.table;
 279                 table_len = sc_table.len;
 280                 unknown_action_list = &syscall_table->unknown_syscall_dispatch;
 281         }
 282         if (unlikely(id < 0 || id >= table_len)) {
 283                 syscall_entry_event_unknown(unknown_action_list, regs, id);
 284                 return;
 285         }
 286
 287         entry = &table[id];
 288         if (!entry->event_func) {
 289                 syscall_entry_event_unknown(unknown_action_list, regs, id);
 290                 return;
 291         }
 292
 293         if (unlikely(in_compat_syscall())) {
 294                 action_list = &syscall_table->compat_syscall_dispatch[id];
 295         } else {
 296                 action_list = &syscall_table->syscall_dispatch[id];
 297         }
 298         if (unlikely(hlist_empty(action_list)))
 299                 return;
 300
 301         syscall_entry_event_call_func(action_list, entry->event_func, entry->nrargs, regs);
 302 }
 303
 304 static void syscall_exit_event_unknown(struct hlist_head *unknown_action_list_head,
 305         struct pt_regs *regs, long id, long ret)
 306 {
 307         unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 308         struct lttng_kernel_event_common_private *event_priv;
 309
 310         lttng_syscall_get_arguments(current, regs, args);
 311         lttng_hlist_for_each_entry_rcu(event_priv, unknown_action_list_head, u.syscall.node) {
 312                 if (unlikely(in_compat_syscall()))
 313                         __event_probe__compat_syscall_exit_unknown(event_priv->pub, id, ret,
 314                                 args);
 315                 else
 316                         __event_probe__syscall_exit_unknown(event_priv->pub, id, ret, args);
 317         }
 318 }
 319
 320 static __always_inline
 321 void syscall_exit_event_call_func(struct hlist_head *action_list,
 322                 void *func, unsigned int nrargs,
 323                 struct pt_regs *regs, long ret)
 324 {
 325         struct lttng_kernel_event_common_private *event_priv;
 326
 327         switch (nrargs) {
 328         case 0:
 329         {
 330                 void (*fptr)(void *__data, long ret) = func;
 331
 332                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 333                         fptr(event_priv->pub, ret);
 334                 break;
 335         }
 336         case 1:
 337         {
 338                 void (*fptr)(void *__data,
 339                         long ret,
 340                         unsigned long arg0) = func;
 341                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 342
 343                 lttng_syscall_get_arguments(current, regs, args);
 344                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 345                         fptr(event_priv->pub, ret, args[0]);
 346                 break;
 347         }
 348         case 2:
 349         {
 350                 void (*fptr)(void *__data,
 351                         long ret,
 352                         unsigned long arg0,
 353                         unsigned long arg1) = func;
 354                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 355
 356                 lttng_syscall_get_arguments(current, regs, args);
 357                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 358                         fptr(event_priv->pub, ret, args[0], args[1]);
 359                 break;
 360         }
 361         case 3:
 362         {
 363                 void (*fptr)(void *__data,
 364                         long ret,
 365                         unsigned long arg0,
 366                         unsigned long arg1,
 367                         unsigned long arg2) = func;
 368                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 369
 370                 lttng_syscall_get_arguments(current, regs, args);
 371                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 372                         fptr(event_priv->pub, ret, args[0], args[1], args[2]);
 373                 break;
 374         }
 375         case 4:
 376         {
 377                 void (*fptr)(void *__data,
 378                         long ret,
 379                         unsigned long arg0,
 380                         unsigned long arg1,
 381                         unsigned long arg2,
 382                         unsigned long arg3) = func;
 383                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 384
 385                 lttng_syscall_get_arguments(current, regs, args);
 386                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 387                         fptr(event_priv->pub, ret, args[0], args[1], args[2], args[3]);
 388                 break;
 389         }
 390         case 5:
 391         {
 392                 void (*fptr)(void *__data,
 393                         long ret,
 394                         unsigned long arg0,
 395                         unsigned long arg1,
 396                         unsigned long arg2,
 397                         unsigned long arg3,
 398                         unsigned long arg4) = func;
 399                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 400
 401                 lttng_syscall_get_arguments(current, regs, args);
 402                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 403                         fptr(event_priv->pub, ret, args[0], args[1], args[2], args[3], args[4]);
 404                 break;
 405         }
 406         case 6:
 407         {
 408                 void (*fptr)(void *__data,
 409                         long ret,
 410                         unsigned long arg0,
 411                         unsigned long arg1,
 412                         unsigned long arg2,
 413                         unsigned long arg3,
 414                         unsigned long arg4,
 415                         unsigned long arg5) = func;
 416                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 417
 418                 lttng_syscall_get_arguments(current, regs, args);
 419                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 420                         fptr(event_priv->pub, ret, args[0], args[1], args[2],
 421                              args[3], args[4], args[5]);
 422                 break;
 423         }
 424         default:
 425                 break;
 426         }
 427 }
 428
 429 void syscall_exit_event_probe(void *__data, struct pt_regs *regs, long ret)
 430 {
 431         struct lttng_kernel_syscall_table *syscall_table = __data;
 432         struct hlist_head *action_list, *unknown_action_list;
 433         const struct trace_syscall_entry *table, *entry;
 434         size_t table_len;
 435         long id;
 436
 437         id = syscall_get_nr(current, regs);
 438
 439         if (unlikely(in_compat_syscall())) {
 440                 struct lttng_syscall_filter *filter = syscall_table->sc_filter;
 441
 442                 if (id < 0 || id >= NR_compat_syscalls
 443                         || (!READ_ONCE(syscall_table->syscall_all_exit) && !test_bit(id, filter->sc_compat_exit))) {
 444                         /* System call filtered out. */
 445                         return;
 446                 }
 447                 table = compat_sc_exit_table.table;
 448                 table_len = compat_sc_exit_table.len;
 449                 unknown_action_list = &syscall_table->compat_unknown_syscall_exit_dispatch;
 450         } else {
 451                 struct lttng_syscall_filter *filter = syscall_table->sc_filter;
 452
 453                 if (id < 0 || id >= NR_syscalls
 454                         || (!READ_ONCE(syscall_table->syscall_all_exit) && !test_bit(id, filter->sc_exit))) {
 455                         /* System call filtered out. */
 456                         return;
 457                 }
 458                 table = sc_exit_table.table;
 459                 table_len = sc_exit_table.len;
 460                 unknown_action_list = &syscall_table->unknown_syscall_exit_dispatch;
 461         }
 462         if (unlikely(id < 0 || id >= table_len)) {
 463                 syscall_exit_event_unknown(unknown_action_list, regs, id, ret);
 464                 return;
 465         }
 466
 467         entry = &table[id];
 468         if (!entry->event_func) {
 469                 syscall_exit_event_unknown(unknown_action_list, regs, id, ret);
 470                 return;
 471         }
 472
 473         if (unlikely(in_compat_syscall())) {
 474                 action_list = &syscall_table->compat_syscall_exit_dispatch[id];
 475         } else {
 476                 action_list = &syscall_table->syscall_exit_dispatch[id];
 477         }
 478         if (unlikely(hlist_empty(action_list)))
 479                 return;
 480
 481         syscall_exit_event_call_func(action_list, entry->event_func, entry->nrargs,
 482                                regs, ret);
 483 }
 484
 485 static
 486 struct lttng_kernel_syscall_table *get_syscall_table_from_enabler(struct lttng_event_enabler_common *event_enabler)
 487 {
 488         switch (event_enabler->enabler_type) {
 489         case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
 490         {
 491                 struct lttng_event_recorder_enabler *event_recorder_enabler =
 492                         container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
 493                 return &event_recorder_enabler->chan->priv->parent.syscall_table;
 494         }
 495         case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
 496         {
 497                 struct lttng_event_notifier_enabler *event_notifier_enabler =
 498                         container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
 499                 return &event_notifier_enabler->group->syscall_table;
 500         }
 501         default:
 502                 return NULL;
 503         }
 504 }
 505
 506 static
 507 struct lttng_kernel_syscall_table *get_syscall_table_from_event(struct lttng_kernel_event_common *event)
 508 {
 509         switch (event->type) {
 510         case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
 511         {
 512                 struct lttng_kernel_event_recorder *event_recorder =
 513                         container_of(event, struct lttng_kernel_event_recorder, parent);
 514                 return &event_recorder->chan->priv->parent.syscall_table;
 515         }
 516         case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
 517         {
 518                 struct lttng_kernel_event_notifier *event_notifier =
 519                         container_of(event, struct lttng_kernel_event_notifier, parent);
 520                 return &event_notifier->priv->group->syscall_table;
 521         }
 522         default:
 523                 return NULL;
 524         }
 525 }
 526
 527 static
 528 void lttng_syscall_event_enabler_create_event(struct lttng_event_enabler_common *syscall_event_enabler,
 529                 const struct lttng_kernel_event_desc *desc, struct hlist_head *dispatch_table,
 530                 enum sc_type type, unsigned int syscall_nr)
 531 {
 532         struct lttng_kernel_event_common *event;
 533
 534         switch (syscall_event_enabler->enabler_type) {
 535         case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
 536         {
 537                 struct lttng_event_recorder_enabler *syscall_event_recorder_enabler =
 538                         container_of(syscall_event_enabler, struct lttng_event_recorder_enabler, parent);
 539                 struct lttng_event_recorder_enabler *event_recorder_enabler;
 540                 struct lttng_kernel_abi_event ev;
 541
 542                 /* We need to create an event for this syscall/enabler. */
 543                 memset(&ev, 0, sizeof(ev));
 544                 switch (type) {
 545                 case SC_TYPE_ENTRY:
 546                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 547                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 548                         break;
 549                 case SC_TYPE_EXIT:
 550                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 551                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 552                         break;
 553                 case SC_TYPE_COMPAT_ENTRY:
 554                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 555                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 556                         break;
 557                 case SC_TYPE_COMPAT_EXIT:
 558                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 559                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 560                         break;
 561                 }
 562                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1);
 563                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 564                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 565                 event_recorder_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev,
 566                                 syscall_event_recorder_enabler->chan);
 567                 WARN_ON_ONCE(!event_recorder_enabler);
 568                 if (!event_recorder_enabler)
 569                         return;
 570                 event = _lttng_kernel_event_create(&event_recorder_enabler->parent, desc);
 571                 WARN_ON_ONCE(IS_ERR(event));
 572                 lttng_event_enabler_destroy(&event_recorder_enabler->parent);
 573                 if (IS_ERR(event)) {
 574                         printk(KERN_INFO "Unable to create event recorder %s\n", desc->event_name);
 575                         return;
 576                 }
 577                 event->priv->u.syscall.syscall_id = syscall_nr;
 578                 if (dispatch_table)
 579                         hlist_add_head_rcu(&event->priv->u.syscall.node, dispatch_table);
 580                 break;
 581         }
 582         case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
 583         {
 584                 struct lttng_event_notifier_enabler *syscall_event_notifier_enabler =
 585                         container_of(syscall_event_enabler, struct lttng_event_notifier_enabler, parent);
 586                 struct lttng_event_notifier_enabler *event_notifier_enabler;
 587                 struct lttng_kernel_abi_event_notifier event_notifier_param;
 588                 uint64_t user_token = syscall_event_enabler->user_token;
 589                 uint64_t error_counter_index = syscall_event_notifier_enabler->error_counter_index;
 590
 591                 memset(&event_notifier_param, 0, sizeof(event_notifier_param));
 592                 switch (type) {
 593                 case SC_TYPE_ENTRY:
 594                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 595                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 596                         break;
 597                 case SC_TYPE_EXIT:
 598                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 599                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 600                         break;
 601                 case SC_TYPE_COMPAT_ENTRY:
 602                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 603                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 604                         break;
 605                 case SC_TYPE_COMPAT_EXIT:
 606                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 607                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 608                         break;
 609                 }
 610                 strncat(event_notifier_param.event.name, desc->event_name,
 611                         LTTNG_KERNEL_ABI_SYM_NAME_LEN - strlen(event_notifier_param.event.name) - 1);
 612                 event_notifier_param.event.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 613                 event_notifier_param.event.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 614                 event_notifier_param.event.token = user_token;
 615                 event_notifier_param.error_counter_index = error_counter_index;
 616
 617                 event_notifier_enabler = lttng_event_notifier_enabler_create(LTTNG_ENABLER_FORMAT_NAME,
 618                                 &event_notifier_param, syscall_event_notifier_enabler->group);
 619                 WARN_ON_ONCE(!event_notifier_enabler);
 620                 event = _lttng_kernel_event_create(&event_notifier_enabler->parent, desc);
 621                 WARN_ON_ONCE(IS_ERR(event));
 622                 lttng_event_enabler_destroy(&event_notifier_enabler->parent);
 623                 if (IS_ERR(event)) {
 624                         printk(KERN_INFO "Unable to create event notifier %s\n", desc->event_name);
 625                         return;
 626                 }
 627                 event->priv->u.syscall.syscall_id = syscall_nr;
 628                 if (dispatch_table)
 629                         hlist_add_head_rcu(&event->priv->u.syscall.node, dispatch_table);
 630                 break;
 631         }
 632         default:
 633                 break;
 634         }
 635 }
 636
 637 static
 638 void lttng_syscall_event_enabler_create_matching_syscall_table_events(struct lttng_event_enabler_common *syscall_event_enabler_common,
 639                 const struct trace_syscall_entry *table, size_t table_len, enum sc_type type)
 640 {
 641         struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(syscall_event_enabler_common);
 642         const struct lttng_kernel_event_desc *desc;
 643         unsigned int i;
 644
 645 #ifndef CONFIG_COMPAT
 646         if (type == SC_TYPE_COMPAT_ENTRY || type == SC_TYPE_COMPAT_EXIT)
 647                 return;
 648 #endif
 649         /* iterate over all syscall and create event that match */
 650         for (i = 0; i < table_len; i++) {
 651                 struct lttng_kernel_event_common_private *event_priv;
 652                 struct hlist_head *head;
 653                 bool found = false;
 654
 655                 desc = table[i].desc;
 656                 if (!desc) {
 657                         /* Unknown syscall */
 658                         continue;
 659                 }
 660
 661                 if (!lttng_desc_match_enabler(desc, syscall_event_enabler_common))
 662                         continue;
 663
 664                 /*
 665                  * Check if already created.
 666                  */
 667                 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
 668                 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
 669                         if (lttng_event_enabler_desc_match_event(syscall_event_enabler_common, desc, event_priv->pub)) {
 670                                 found = true;
 671                                 break;
 672                         }
 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 #ifndef CONFIG_COMPAT
 707         if (type == SC_TYPE_COMPAT_ENTRY || type == SC_TYPE_COMPAT_EXIT)
 708                 return;
 709 #endif
 710         /*
 711          * Considering that currently system calls can only be enabled on a per
 712          * name basis (or wildcard based on a name), unknown syscall events are
 713          * only used when matching *all* system calls, because this is the only
 714          * case which can be associated with an unknown system call.
 715          *
 716          * When enabling system call on a per system call number basis will be
 717          * supported, this will need to be revisited.
 718          */
 719         if (!lttng_syscall_event_enabler_is_wildcard_all(event_enabler))
 720                 return;
 721
 722         switch (type) {
 723         case SC_TYPE_ENTRY:
 724                 desc = &__event_desc___syscall_entry_unknown;
 725                 unknown_dispatch_list = &syscall_table->unknown_syscall_dispatch;
 726                 break;
 727         case SC_TYPE_EXIT:
 728                 desc = &__event_desc___syscall_exit_unknown;
 729                 unknown_dispatch_list = &syscall_table->unknown_syscall_exit_dispatch;
 730                 break;
 731         case SC_TYPE_COMPAT_ENTRY:
 732                 desc = &__event_desc___compat_syscall_entry_unknown;
 733                 unknown_dispatch_list = &syscall_table->compat_unknown_syscall_dispatch;
 734                 break;
 735         case SC_TYPE_COMPAT_EXIT:
 736                 desc = &__event_desc___compat_syscall_exit_unknown;
 737                 unknown_dispatch_list = &syscall_table->compat_unknown_syscall_exit_dispatch;
 738                 break;
 739         default:
 740                 WARN_ON_ONCE(1);
 741         }
 742
 743         /*
 744          * Check if already created.
 745          */
 746         head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
 747         lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
 748                 if (lttng_event_enabler_desc_match_event(event_enabler, desc, event_priv->pub)) {
 749                         found = true;
 750                         break;
 751                 }
 752         }
 753         if (!found)
 754                 lttng_syscall_event_enabler_create_event(event_enabler, desc, unknown_dispatch_list, type, -1U);
 755 }
 756
 757 static
 758 void lttng_syscall_event_enabler_create_matching_events(struct lttng_event_enabler_common *event_enabler)
 759 {
 760         enum lttng_kernel_abi_syscall_entryexit entryexit = event_enabler->event_param.u.syscall.entryexit;
 761
 762         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
 763                 lttng_syscall_event_enabler_create_matching_syscall_table_events(event_enabler,
 764                         sc_table.table, sc_table.len, SC_TYPE_ENTRY);
 765                 lttng_syscall_event_enabler_create_matching_syscall_table_events(event_enabler,
 766                         compat_sc_table.table, compat_sc_table.len, SC_TYPE_COMPAT_ENTRY);
 767                 create_unknown_syscall_event(event_enabler, SC_TYPE_ENTRY);
 768                 create_unknown_syscall_event(event_enabler, SC_TYPE_COMPAT_ENTRY);
 769         }
 770
 771         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
 772                 lttng_syscall_event_enabler_create_matching_syscall_table_events(event_enabler,
 773                         sc_exit_table.table, sc_exit_table.len, SC_TYPE_EXIT);
 774                 lttng_syscall_event_enabler_create_matching_syscall_table_events(event_enabler,
 775                         compat_sc_exit_table.table, compat_sc_exit_table.len, SC_TYPE_COMPAT_EXIT);
 776                 create_unknown_syscall_event(event_enabler, SC_TYPE_EXIT);
 777                 create_unknown_syscall_event(event_enabler, SC_TYPE_COMPAT_EXIT);
 778         }
 779 }
 780
 781 /*
 782  * Should be called with sessions lock held.
 783  */
 784 int lttng_event_enabler_create_syscall_events_if_missing(struct lttng_event_enabler_common *syscall_event_enabler)
 785 {
 786         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(syscall_event_enabler);
 787         int ret;
 788
 789         if (!syscall_table->syscall_dispatch) {
 790                 /* create syscall table mapping syscall to events */
 791                 syscall_table->syscall_dispatch = kzalloc(sizeof(struct hlist_head) * sc_table.len, GFP_KERNEL);
 792                 if (!syscall_table->syscall_dispatch)
 793                         return -ENOMEM;
 794         }
 795         if (!syscall_table->syscall_exit_dispatch) {
 796                 /* create syscall table mapping syscall to events */
 797                 syscall_table->syscall_exit_dispatch = kzalloc(sizeof(struct hlist_head) * sc_exit_table.len, GFP_KERNEL);
 798                 if (!syscall_table->syscall_exit_dispatch)
 799                         return -ENOMEM;
 800         }
 801
 802 #ifdef CONFIG_COMPAT
 803         if (!syscall_table->compat_syscall_dispatch) {
 804                 /* create syscall table mapping compat syscall to events */
 805                 syscall_table->compat_syscall_dispatch = kzalloc(sizeof(struct hlist_head) * compat_sc_table.len, GFP_KERNEL);
 806                 if (!syscall_table->compat_syscall_dispatch)
 807                         return -ENOMEM;
 808         }
 809
 810         if (!syscall_table->compat_syscall_exit_dispatch) {
 811                 /* create syscall table mapping compat syscall to events */
 812                 syscall_table->compat_syscall_exit_dispatch = kzalloc(sizeof(struct hlist_head) * compat_sc_exit_table.len, GFP_KERNEL);
 813                 if (!syscall_table->compat_syscall_exit_dispatch)
 814                         return -ENOMEM;
 815         }
 816 #endif
 817         if (!syscall_table->sc_filter) {
 818                 syscall_table->sc_filter = kzalloc(sizeof(struct lttng_syscall_filter),
 819                                 GFP_KERNEL);
 820                 if (!syscall_table->sc_filter)
 821                         return -ENOMEM;
 822         }
 823
 824         if (!syscall_table->sys_enter_registered) {
 825                 ret = lttng_wrapper_tracepoint_probe_register("sys_enter",
 826                                 (void *) syscall_entry_event_probe, syscall_table);
 827                 if (ret)
 828                         return ret;
 829                 syscall_table->sys_enter_registered = 1;
 830         }
 831         if (!syscall_table->sys_exit_registered) {
 832                 ret = lttng_wrapper_tracepoint_probe_register("sys_exit",
 833                                 (void *) syscall_exit_event_probe, syscall_table);
 834                 if (ret) {
 835                         WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter",
 836                                 (void *) syscall_entry_event_probe, syscall_table));
 837                         return ret;
 838                 }
 839                 syscall_table->sys_exit_registered = 1;
 840         }
 841
 842         lttng_syscall_event_enabler_create_matching_events(syscall_event_enabler);
 843
 844         return ret;
 845 }
 846
 847 int lttng_syscalls_unregister_syscall_table(struct lttng_kernel_syscall_table *syscall_table)
 848 {
 849         int ret;
 850
 851         if (!syscall_table->syscall_dispatch)
 852                 return 0;
 853         if (syscall_table->sys_enter_registered) {
 854                 ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter",
 855                                 (void *) syscall_entry_event_probe, syscall_table);
 856                 if (ret)
 857                         return ret;
 858                 syscall_table->sys_enter_registered = 0;
 859         }
 860         if (syscall_table->sys_exit_registered) {
 861                 ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit",
 862                                 (void *) syscall_exit_event_probe, syscall_table);
 863                 if (ret)
 864                         return ret;
 865                 syscall_table->sys_exit_registered = 0;
 866         }
 867         return 0;
 868 }
 869
 870 int lttng_syscalls_destroy_syscall_table(struct lttng_kernel_syscall_table *syscall_table)
 871 {
 872         kfree(syscall_table->syscall_dispatch);
 873         kfree(syscall_table->syscall_exit_dispatch);
 874 #ifdef CONFIG_COMPAT
 875         kfree(syscall_table->compat_syscall_dispatch);
 876         kfree(syscall_table->compat_syscall_exit_dispatch);
 877 #endif
 878         kfree(syscall_table->sc_filter);
 879         return 0;
 880 }
 881
 882 static
 883 int get_syscall_nr(const char *syscall_name)
 884 {
 885         int syscall_nr = -1;
 886         int i;
 887
 888         for (i = 0; i < sc_table.len; i++) {
 889                 const struct trace_syscall_entry *entry;
 890                 const char *it_name;
 891
 892                 entry = &sc_table.table[i];
 893                 if (!entry->desc)
 894                         continue;
 895                 it_name = entry->desc->event_name;
 896                 it_name += strlen(SYSCALL_ENTRY_STR);
 897                 if (!strcmp(syscall_name, it_name)) {
 898                         syscall_nr = i;
 899                         break;
 900                 }
 901         }
 902         return syscall_nr;
 903 }
 904
 905 static
 906 int get_compat_syscall_nr(const char *syscall_name)
 907 {
 908         int syscall_nr = -1;
 909         int i;
 910
 911         for (i = 0; i < compat_sc_table.len; i++) {
 912                 const struct trace_syscall_entry *entry;
 913                 const char *it_name;
 914
 915                 entry = &compat_sc_table.table[i];
 916                 if (!entry->desc)
 917                         continue;
 918                 it_name = entry->desc->event_name;
 919                 it_name += strlen(COMPAT_SYSCALL_ENTRY_STR);
 920                 if (!strcmp(syscall_name, it_name)) {
 921                         syscall_nr = i;
 922                         break;
 923                 }
 924         }
 925         return syscall_nr;
 926 }
 927
 928 static
 929 uint32_t get_sc_tables_len(void)
 930 {
 931         return sc_table.len + compat_sc_table.len;
 932 }
 933
 934 static
 935 const char *get_syscall_name(const char *desc_name,
 936                 enum lttng_syscall_abi abi,
 937                 enum lttng_syscall_entryexit entryexit)
 938 {
 939         size_t prefix_len = 0;
 940
 941
 942         switch (entryexit) {
 943         case LTTNG_SYSCALL_ENTRY:
 944                 switch (abi) {
 945                 case LTTNG_SYSCALL_ABI_NATIVE:
 946                         prefix_len = strlen(SYSCALL_ENTRY_STR);
 947                         break;
 948                 case LTTNG_SYSCALL_ABI_COMPAT:
 949                         prefix_len = strlen(COMPAT_SYSCALL_ENTRY_STR);
 950                         break;
 951                 }
 952                 break;
 953         case LTTNG_SYSCALL_EXIT:
 954                 switch (abi) {
 955                 case LTTNG_SYSCALL_ABI_NATIVE:
 956                         prefix_len = strlen(SYSCALL_EXIT_STR);
 957                         break;
 958                 case LTTNG_SYSCALL_ABI_COMPAT:
 959                         prefix_len = strlen(COMPAT_SYSCALL_EXIT_STR);
 960                         break;
 961                 }
 962                 break;
 963         }
 964         WARN_ON_ONCE(prefix_len == 0);
 965         return desc_name + prefix_len;
 966 }
 967
 968 static
 969 int lttng_syscall_filter_enable(
 970                 struct lttng_syscall_filter *filter,
 971                 const char *desc_name, enum lttng_syscall_abi abi,
 972                 enum lttng_syscall_entryexit entryexit)
 973 {
 974         const char *syscall_name;
 975         unsigned long *bitmap;
 976         int syscall_nr;
 977
 978         syscall_name = get_syscall_name(desc_name, abi, entryexit);
 979
 980         switch (abi) {
 981         case LTTNG_SYSCALL_ABI_NATIVE:
 982                 syscall_nr = get_syscall_nr(syscall_name);
 983                 break;
 984         case LTTNG_SYSCALL_ABI_COMPAT:
 985                 syscall_nr = get_compat_syscall_nr(syscall_name);
 986                 break;
 987         default:
 988                 return -EINVAL;
 989         }
 990         if (syscall_nr < 0)
 991                 return -ENOENT;
 992
 993         switch (entryexit) {
 994         case LTTNG_SYSCALL_ENTRY:
 995                 switch (abi) {
 996                 case LTTNG_SYSCALL_ABI_NATIVE:
 997                         bitmap = filter->sc_entry;
 998                         break;
 999                 case LTTNG_SYSCALL_ABI_COMPAT:
1000                         bitmap = filter->sc_compat_entry;
1001                         break;
1002                 default:
1003                         return -EINVAL;
1004                 }
1005                 break;
1006         case LTTNG_SYSCALL_EXIT:
1007                 switch (abi) {
1008                 case LTTNG_SYSCALL_ABI_NATIVE:
1009                         bitmap = filter->sc_exit;
1010                         break;
1011                 case LTTNG_SYSCALL_ABI_COMPAT:
1012                         bitmap = filter->sc_compat_exit;
1013                         break;
1014                 default:
1015                         return -EINVAL;
1016                 }
1017                 break;
1018         default:
1019                 return -EINVAL;
1020         }
1021         if (test_bit(syscall_nr, bitmap))
1022                 return -EEXIST;
1023         bitmap_set(bitmap, syscall_nr, 1);
1024         return 0;
1025 }
1026
1027 int lttng_syscall_filter_enable_event(struct lttng_kernel_event_common *event)
1028 {
1029         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event);
1030         unsigned int syscall_id = event->priv->u.syscall.syscall_id;
1031         struct hlist_head *dispatch_list;
1032         int ret;
1033
1034         WARN_ON_ONCE(event->priv->instrumentation != LTTNG_KERNEL_ABI_SYSCALL);
1035
1036         ret = lttng_syscall_filter_enable(syscall_table->sc_filter,
1037                 event->priv->desc->event_name, event->priv->u.syscall.abi,
1038                 event->priv->u.syscall.entryexit);
1039         if (ret)
1040                 return ret;
1041
1042         switch (event->priv->u.syscall.entryexit) {
1043         case LTTNG_SYSCALL_ENTRY:
1044                 switch (event->priv->u.syscall.abi) {
1045                 case LTTNG_SYSCALL_ABI_NATIVE:
1046                         dispatch_list = &syscall_table->syscall_dispatch[syscall_id];
1047                         break;
1048                 case LTTNG_SYSCALL_ABI_COMPAT:
1049                         dispatch_list = &syscall_table->compat_syscall_dispatch[syscall_id];
1050                         break;
1051                 default:
1052                         ret = -EINVAL;
1053                         goto end;
1054                 }
1055                 break;
1056         case LTTNG_SYSCALL_EXIT:
1057                 switch (event->priv->u.syscall.abi) {
1058                 case LTTNG_SYSCALL_ABI_NATIVE:
1059                         dispatch_list = &syscall_table->syscall_exit_dispatch[syscall_id];
1060                         break;
1061                 case LTTNG_SYSCALL_ABI_COMPAT:
1062                         dispatch_list = &syscall_table->compat_syscall_exit_dispatch[syscall_id];
1063                         break;
1064                 default:
1065                         ret = -EINVAL;
1066                         goto end;
1067                 }
1068                 break;
1069         default:
1070                 ret = -EINVAL;
1071                 goto end;
1072         }
1073
1074         hlist_add_head_rcu(&event->priv->u.syscall.node, dispatch_list);
1075 end:
1076         return ret;
1077 }
1078
1079 static
1080 int lttng_syscall_filter_disable(struct lttng_syscall_filter *filter,
1081                 const char *desc_name, enum lttng_syscall_abi abi,
1082                 enum lttng_syscall_entryexit entryexit)
1083 {
1084         const char *syscall_name;
1085         unsigned long *bitmap;
1086         int syscall_nr;
1087
1088         syscall_name = get_syscall_name(desc_name, abi, entryexit);
1089
1090         switch (abi) {
1091         case LTTNG_SYSCALL_ABI_NATIVE:
1092                 syscall_nr = get_syscall_nr(syscall_name);
1093                 break;
1094         case LTTNG_SYSCALL_ABI_COMPAT:
1095                 syscall_nr = get_compat_syscall_nr(syscall_name);
1096                 break;
1097         default:
1098                 return -EINVAL;
1099         }
1100         if (syscall_nr < 0)
1101                 return -ENOENT;
1102
1103         switch (entryexit) {
1104         case LTTNG_SYSCALL_ENTRY:
1105                 switch (abi) {
1106                 case LTTNG_SYSCALL_ABI_NATIVE:
1107                         bitmap = filter->sc_entry;
1108                         break;
1109                 case LTTNG_SYSCALL_ABI_COMPAT:
1110                         bitmap = filter->sc_compat_entry;
1111                         break;
1112                 default:
1113                         return -EINVAL;
1114                 }
1115                 break;
1116         case LTTNG_SYSCALL_EXIT:
1117                 switch (abi) {
1118                 case LTTNG_SYSCALL_ABI_NATIVE:
1119                         bitmap = filter->sc_exit;
1120                         break;
1121                 case LTTNG_SYSCALL_ABI_COMPAT:
1122                         bitmap = filter->sc_compat_exit;
1123                         break;
1124                 default:
1125                         return -EINVAL;
1126                 }
1127                 break;
1128         default:
1129                 return -EINVAL;
1130         }
1131         if (!test_bit(syscall_nr, bitmap))
1132                 return -EEXIST;
1133         bitmap_clear(bitmap, syscall_nr, 1);
1134
1135         return 0;
1136 }
1137
1138 int lttng_syscall_filter_disable_event(struct lttng_kernel_event_common *event)
1139 {
1140         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event);
1141         int ret;
1142
1143         ret = lttng_syscall_filter_disable(syscall_table->sc_filter,
1144                 event->priv->desc->event_name, event->priv->u.syscall.abi,
1145                 event->priv->u.syscall.entryexit);
1146         if (ret)
1147                 return ret;
1148         hlist_del_rcu(&event->priv->u.syscall.node);
1149         return 0;
1150 }
1151
1152 void lttng_syscall_table_set_wildcard_all(struct lttng_event_enabler_common *event_enabler)
1153 {
1154         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(event_enabler);
1155         enum lttng_kernel_abi_syscall_entryexit entryexit;
1156         int enabled = event_enabler->enabled;
1157
1158         if (!lttng_syscall_event_enabler_is_wildcard_all(event_enabler))
1159                 return;
1160         entryexit = event_enabler->event_param.u.syscall.entryexit;
1161         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
1162                 WRITE_ONCE(syscall_table->syscall_all_entry, enabled);
1163
1164         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
1165                 WRITE_ONCE(syscall_table->syscall_all_exit, enabled);
1166 }
1167
1168 static
1169 const struct trace_syscall_entry *syscall_list_get_entry(loff_t *pos)
1170 {
1171         const struct trace_syscall_entry *entry;
1172         int iter = 0;
1173
1174         for (entry = sc_table.table;
1175                         entry < sc_table.table + sc_table.len;
1176                          entry++) {
1177                 if (iter++ >= *pos)
1178                         return entry;
1179         }
1180         for (entry = compat_sc_table.table;
1181                         entry < compat_sc_table.table + compat_sc_table.len;
1182                          entry++) {
1183                 if (iter++ >= *pos)
1184                         return entry;
1185         }
1186         /* End of list */
1187         return NULL;
1188 }
1189
1190 static
1191 void *syscall_list_start(struct seq_file *m, loff_t *pos)
1192 {
1193         return (void *) syscall_list_get_entry(pos);
1194 }
1195
1196 static
1197 void *syscall_list_next(struct seq_file *m, void *p, loff_t *ppos)
1198 {
1199         (*ppos)++;
1200         return (void *) syscall_list_get_entry(ppos);
1201 }
1202
1203 static
1204 void syscall_list_stop(struct seq_file *m, void *p)
1205 {
1206 }
1207
1208 static
1209 int get_sc_table(const struct trace_syscall_entry *entry,
1210                 const struct trace_syscall_entry **table,
1211                 unsigned int *bitness)
1212 {
1213         if (entry >= sc_table.table && entry < sc_table.table + sc_table.len) {
1214                 if (bitness)
1215                         *bitness = BITS_PER_LONG;
1216                 if (table)
1217                         *table = sc_table.table;
1218                 return 0;
1219         }
1220         if (!(entry >= compat_sc_table.table
1221                         && entry < compat_sc_table.table + compat_sc_table.len)) {
1222                 return -EINVAL;
1223         }
1224         if (bitness)
1225                 *bitness = 32;
1226         if (table)
1227                 *table = compat_sc_table.table;
1228         return 0;
1229 }
1230
1231 static
1232 int syscall_list_show(struct seq_file *m, void *p)
1233 {
1234         const struct trace_syscall_entry *table, *entry = p;
1235         unsigned int bitness;
1236         unsigned long index;
1237         int ret;
1238         const char *name;
1239
1240         ret = get_sc_table(entry, &table, &bitness);
1241         if (ret)
1242                 return ret;
1243         if (!entry->desc)
1244                 return 0;
1245         if (table == sc_table.table) {
1246                 index = entry - table;
1247                 name = &entry->desc->event_name[strlen(SYSCALL_ENTRY_STR)];
1248         } else {
1249                 index = (entry - table) + sc_table.len;
1250                 name = &entry->desc->event_name[strlen(COMPAT_SYSCALL_ENTRY_STR)];
1251         }
1252         seq_printf(m,   "syscall { index = %lu; name = %s; bitness = %u; };\n",
1253                 index, name, bitness);
1254         return 0;
1255 }
1256
1257 static
1258 const struct seq_operations lttng_syscall_list_seq_ops = {
1259         .start = syscall_list_start,
1260         .next = syscall_list_next,
1261         .stop = syscall_list_stop,
1262         .show = syscall_list_show,
1263 };
1264
1265 static
1266 int lttng_syscall_list_open(struct inode *inode, struct file *file)
1267 {
1268         return seq_open(file, &lttng_syscall_list_seq_ops);
1269 }
1270
1271 const struct file_operations lttng_syscall_list_fops = {
1272         .owner = THIS_MODULE,
1273         .open = lttng_syscall_list_open,
1274         .read = seq_read,
1275         .llseek = seq_lseek,
1276         .release = seq_release,
1277 };
1278
1279 /*
1280  * A syscall is enabled if it is traced for either entry or exit.
1281  */
1282 long lttng_syscall_table_get_active_mask(struct lttng_kernel_syscall_table *syscall_table,
1283                 struct lttng_kernel_abi_syscall_mask __user *usyscall_mask)
1284 {
1285         uint32_t len, sc_tables_len, bitmask_len;
1286         int ret = 0, bit;
1287         char *tmp_mask;
1288         struct lttng_syscall_filter *filter;
1289
1290         ret = get_user(len, &usyscall_mask->len);
1291         if (ret)
1292                 return ret;
1293         sc_tables_len = get_sc_tables_len();
1294         bitmask_len = ALIGN(sc_tables_len, 8) >> 3;
1295         if (len < sc_tables_len) {
1296                 return put_user(sc_tables_len, &usyscall_mask->len);
1297         }
1298         /* Array is large enough, we can copy array to user-space. */
1299         tmp_mask = kzalloc(bitmask_len, GFP_KERNEL);
1300         if (!tmp_mask)
1301                 return -ENOMEM;
1302         filter = syscall_table->sc_filter;
1303
1304         for (bit = 0; bit < sc_table.len; bit++) {
1305                 char state;
1306
1307                 if (syscall_table->syscall_dispatch) {
1308                         if (!(READ_ONCE(syscall_table->syscall_all_entry)
1309                                         || READ_ONCE(syscall_table->syscall_all_exit)) && filter)
1310                                 state = test_bit(bit, filter->sc_entry)
1311                                         || test_bit(bit, filter->sc_exit);
1312                         else
1313                                 state = 1;
1314                 } else {
1315                         state = 0;
1316                 }
1317                 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1318         }
1319         for (; bit < sc_tables_len; bit++) {
1320                 char state;
1321
1322                 if (syscall_table->compat_syscall_dispatch) {
1323                         if (!(READ_ONCE(syscall_table->syscall_all_entry)
1324                                         || READ_ONCE(syscall_table->syscall_all_exit)) && filter)
1325                                 state = test_bit(bit - sc_table.len,
1326                                                 filter->sc_compat_entry)
1327                                         || test_bit(bit - sc_table.len,
1328                                                 filter->sc_compat_exit);
1329                         else
1330                                 state = 1;
1331                 } else {
1332                         state = 0;
1333                 }
1334                 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1335         }
1336         if (copy_to_user(usyscall_mask->mask, tmp_mask, bitmask_len))
1337                 ret = -EFAULT;
1338         kfree(tmp_mask);
1339         return ret;
1340 }
1341
1342 int lttng_abi_syscall_list(void)
1343 {
1344         struct file *syscall_list_file;
1345         int file_fd, ret;
1346
1347         file_fd = lttng_get_unused_fd();
1348         if (file_fd < 0) {
1349                 ret = file_fd;
1350                 goto fd_error;
1351         }
1352
1353         syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
1354                                           &lttng_syscall_list_fops,
1355                                           NULL, O_RDWR);
1356         if (IS_ERR(syscall_list_file)) {
1357                 ret = PTR_ERR(syscall_list_file);
1358                 goto file_error;
1359         }
1360         ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
1361         if (ret < 0)
1362                 goto open_error;
1363         fd_install(file_fd, syscall_list_file);
1364         return file_fd;
1365
1366 open_error:
1367         fput(syscall_list_file);
1368 file_error:
1369         put_unused_fd(file_fd);
1370 fd_error:
1371         return ret;
1372 }