1 #include <trace/syscall.h> 2 #include <trace/events/syscalls.h> 3 #include <linux/syscalls.h> 4 #include <linux/slab.h> 5 #include <linux/kernel.h> 6 #include <linux/module.h> /* for MODULE_NAME_LEN via KSYM_SYMBOL_LEN */ 7 #include <linux/ftrace.h> 8 #include <linux/perf_event.h> 9 #include <asm/syscall.h> 10 11 #include "trace_output.h" 12 #include "trace.h" 13 14 static DEFINE_MUTEX(syscall_trace_lock); 15 16 static int syscall_enter_register(struct trace_event_call *event, 17 enum trace_reg type, void *data); 18 static int syscall_exit_register(struct trace_event_call *event, 19 enum trace_reg type, void *data); 20 21 static struct list_head * 22 syscall_get_enter_fields(struct trace_event_call *call) 23 { 24 struct syscall_metadata *entry = call->data; 25 26 return &entry->enter_fields; 27 } 28 29 extern struct syscall_metadata *__start_syscalls_metadata[]; 30 extern struct syscall_metadata *__stop_syscalls_metadata[]; 31 32 static struct syscall_metadata **syscalls_metadata; 33 34 #ifndef ARCH_HAS_SYSCALL_MATCH_SYM_NAME 35 static inline bool arch_syscall_match_sym_name(const char *sym, const char *name) 36 { 37 /* 38 * Only compare after the "sys" prefix. Archs that use 39 * syscall wrappers may have syscalls symbols aliases prefixed 40 * with ".SyS" or ".sys" instead of "sys", leading to an unwanted 41 * mismatch. 42 */ 43 return !strcmp(sym + 3, name + 3); 44 } 45 #endif 46 47 #ifdef ARCH_TRACE_IGNORE_COMPAT_SYSCALLS 48 /* 49 * Some architectures that allow for 32bit applications 50 * to run on a 64bit kernel, do not map the syscalls for 51 * the 32bit tasks the same as they do for 64bit tasks. 52 * 53 * *cough*x86*cough* 54 * 55 * In such a case, instead of reporting the wrong syscalls, 56 * simply ignore them. 57 * 58 * For an arch to ignore the compat syscalls it needs to 59 * define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS as well as 60 * define the function arch_trace_is_compat_syscall() to let 61 * the tracing system know that it should ignore it. 62 */ 63 static int 64 trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs) 65 { 66 if (unlikely(arch_trace_is_compat_syscall(regs))) 67 return -1; 68 69 return syscall_get_nr(task, regs); 70 } 71 #else 72 static inline int 73 trace_get_syscall_nr(struct task_struct *task, struct pt_regs *regs) 74 { 75 return syscall_get_nr(task, regs); 76 } 77 #endif /* ARCH_TRACE_IGNORE_COMPAT_SYSCALLS */ 78 79 static __init struct syscall_metadata * 80 find_syscall_meta(unsigned long syscall) 81 { 82 struct syscall_metadata **start; 83 struct syscall_metadata **stop; 84 char str[KSYM_SYMBOL_LEN]; 85 86 87 start = __start_syscalls_metadata; 88 stop = __stop_syscalls_metadata; 89 kallsyms_lookup(syscall, NULL, NULL, NULL, str); 90 91 if (arch_syscall_match_sym_name(str, "sys_ni_syscall")) 92 return NULL; 93 94 for ( ; start < stop; start++) { 95 if ((*start)->name && arch_syscall_match_sym_name(str, (*start)->name)) 96 return *start; 97 } 98 return NULL; 99 } 100 101 static struct syscall_metadata *syscall_nr_to_meta(int nr) 102 { 103 if (!syscalls_metadata || nr >= NR_syscalls || nr < 0) 104 return NULL; 105 106 return syscalls_metadata[nr]; 107 } 108 109 static enum print_line_t 110 print_syscall_enter(struct trace_iterator *iter, int flags, 111 struct trace_event *event) 112 { 113 struct trace_array *tr = iter->tr; 114 struct trace_seq *s = &iter->seq; 115 struct trace_entry *ent = iter->ent; 116 struct syscall_trace_enter *trace; 117 struct syscall_metadata *entry; 118 int i, syscall; 119 120 trace = (typeof(trace))ent; 121 syscall = trace->nr; 122 entry = syscall_nr_to_meta(syscall); 123 124 if (!entry) 125 goto end; 126 127 if (entry->enter_event->event.type != ent->type) { 128 WARN_ON_ONCE(1); 129 goto end; 130 } 131 132 trace_seq_printf(s, "%s(", entry->name); 133 134 for (i = 0; i < entry->nb_args; i++) { 135 136 if (trace_seq_has_overflowed(s)) 137 goto end; 138 139 /* parameter types */ 140 if (tr->trace_flags & TRACE_ITER_VERBOSE) 141 trace_seq_printf(s, "%s ", entry->types[i]); 142 143 /* parameter values */ 144 trace_seq_printf(s, "%s: %lx%s", entry->args[i], 145 trace->args[i], 146 i == entry->nb_args - 1 ? "" : ", "); 147 } 148 149 trace_seq_putc(s, ')'); 150 end: 151 trace_seq_putc(s, '\n'); 152 153 return trace_handle_return(s); 154 } 155 156 static enum print_line_t 157 print_syscall_exit(struct trace_iterator *iter, int flags, 158 struct trace_event *event) 159 { 160 struct trace_seq *s = &iter->seq; 161 struct trace_entry *ent = iter->ent; 162 struct syscall_trace_exit *trace; 163 int syscall; 164 struct syscall_metadata *entry; 165 166 trace = (typeof(trace))ent; 167 syscall = trace->nr; 168 entry = syscall_nr_to_meta(syscall); 169 170 if (!entry) { 171 trace_seq_putc(s, '\n'); 172 goto out; 173 } 174 175 if (entry->exit_event->event.type != ent->type) { 176 WARN_ON_ONCE(1); 177 return TRACE_TYPE_UNHANDLED; 178 } 179 180 trace_seq_printf(s, "%s -> 0x%lx\n", entry->name, 181 trace->ret); 182 183 out: 184 return trace_handle_return(s); 185 } 186 187 extern char *__bad_type_size(void); 188 189 #define SYSCALL_FIELD(type, name) \ 190 sizeof(type) != sizeof(trace.name) ? \ 191 __bad_type_size() : \ 192 #type, #name, offsetof(typeof(trace), name), \ 193 sizeof(trace.name), is_signed_type(type) 194 195 static int __init 196 __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len) 197 { 198 int i; 199 int pos = 0; 200 201 /* When len=0, we just calculate the needed length */ 202 #define LEN_OR_ZERO (len ? len - pos : 0) 203 204 pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); 205 for (i = 0; i < entry->nb_args; i++) { 206 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s: 0x%%0%zulx%s", 207 entry->args[i], sizeof(unsigned long), 208 i == entry->nb_args - 1 ? "" : ", "); 209 } 210 pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); 211 212 for (i = 0; i < entry->nb_args; i++) { 213 pos += snprintf(buf + pos, LEN_OR_ZERO, 214 ", ((unsigned long)(REC->%s))", entry->args[i]); 215 } 216 217 #undef LEN_OR_ZERO 218 219 /* return the length of print_fmt */ 220 return pos; 221 } 222 223 static int __init set_syscall_print_fmt(struct trace_event_call *call) 224 { 225 char *print_fmt; 226 int len; 227 struct syscall_metadata *entry = call->data; 228 229 if (entry->enter_event != call) { 230 call->print_fmt = "\"0x%lx\", REC->ret"; 231 return 0; 232 } 233 234 /* First: called with 0 length to calculate the needed length */ 235 len = __set_enter_print_fmt(entry, NULL, 0); 236 237 print_fmt = kmalloc(len + 1, GFP_KERNEL); 238 if (!print_fmt) 239 return -ENOMEM; 240 241 /* Second: actually write the @print_fmt */ 242 __set_enter_print_fmt(entry, print_fmt, len + 1); 243 call->print_fmt = print_fmt; 244 245 return 0; 246 } 247 248 static void __init free_syscall_print_fmt(struct trace_event_call *call) 249 { 250 struct syscall_metadata *entry = call->data; 251 252 if (entry->enter_event == call) 253 kfree(call->print_fmt); 254 } 255 256 static int __init syscall_enter_define_fields(struct trace_event_call *call) 257 { 258 struct syscall_trace_enter trace; 259 struct syscall_metadata *meta = call->data; 260 int ret; 261 int i; 262 int offset = offsetof(typeof(trace), args); 263 264 ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER); 265 if (ret) 266 return ret; 267 268 for (i = 0; i < meta->nb_args; i++) { 269 ret = trace_define_field(call, meta->types[i], 270 meta->args[i], offset, 271 sizeof(unsigned long), 0, 272 FILTER_OTHER); 273 offset += sizeof(unsigned long); 274 } 275 276 return ret; 277 } 278 279 static int __init syscall_exit_define_fields(struct trace_event_call *call) 280 { 281 struct syscall_trace_exit trace; 282 int ret; 283 284 ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER); 285 if (ret) 286 return ret; 287 288 ret = trace_define_field(call, SYSCALL_FIELD(long, ret), 289 FILTER_OTHER); 290 291 return ret; 292 } 293 294 static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id) 295 { 296 struct trace_array *tr = data; 297 struct trace_event_file *trace_file; 298 struct syscall_trace_enter *entry; 299 struct syscall_metadata *sys_data; 300 struct ring_buffer_event *event; 301 struct ring_buffer *buffer; 302 unsigned long irq_flags; 303 int pc; 304 int syscall_nr; 305 int size; 306 307 syscall_nr = trace_get_syscall_nr(current, regs); 308 if (syscall_nr < 0 || syscall_nr >= NR_syscalls) 309 return; 310 311 /* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE) */ 312 trace_file = rcu_dereference_sched(tr->enter_syscall_files[syscall_nr]); 313 if (!trace_file) 314 return; 315 316 if (trace_trigger_soft_disabled(trace_file)) 317 return; 318 319 sys_data = syscall_nr_to_meta(syscall_nr); 320 if (!sys_data) 321 return; 322 323 size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args; 324 325 local_save_flags(irq_flags); 326 pc = preempt_count(); 327 328 buffer = tr->trace_buffer.buffer; 329 event = trace_buffer_lock_reserve(buffer, 330 sys_data->enter_event->event.type, size, irq_flags, pc); 331 if (!event) 332 return; 333 334 entry = ring_buffer_event_data(event); 335 entry->nr = syscall_nr; 336 syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args); 337 338 event_trigger_unlock_commit(trace_file, buffer, event, entry, 339 irq_flags, pc); 340 } 341 342 static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret) 343 { 344 struct trace_array *tr = data; 345 struct trace_event_file *trace_file; 346 struct syscall_trace_exit *entry; 347 struct syscall_metadata *sys_data; 348 struct ring_buffer_event *event; 349 struct ring_buffer *buffer; 350 unsigned long irq_flags; 351 int pc; 352 int syscall_nr; 353 354 syscall_nr = trace_get_syscall_nr(current, regs); 355 if (syscall_nr < 0 || syscall_nr >= NR_syscalls) 356 return; 357 358 /* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE()) */ 359 trace_file = rcu_dereference_sched(tr->exit_syscall_files[syscall_nr]); 360 if (!trace_file) 361 return; 362 363 if (trace_trigger_soft_disabled(trace_file)) 364 return; 365 366 sys_data = syscall_nr_to_meta(syscall_nr); 367 if (!sys_data) 368 return; 369 370 local_save_flags(irq_flags); 371 pc = preempt_count(); 372 373 buffer = tr->trace_buffer.buffer; 374 event = trace_buffer_lock_reserve(buffer, 375 sys_data->exit_event->event.type, sizeof(*entry), 376 irq_flags, pc); 377 if (!event) 378 return; 379 380 entry = ring_buffer_event_data(event); 381 entry->nr = syscall_nr; 382 entry->ret = syscall_get_return_value(current, regs); 383 384 event_trigger_unlock_commit(trace_file, buffer, event, entry, 385 irq_flags, pc); 386 } 387 388 static int reg_event_syscall_enter(struct trace_event_file *file, 389 struct trace_event_call *call) 390 { 391 struct trace_array *tr = file->tr; 392 int ret = 0; 393 int num; 394 395 num = ((struct syscall_metadata *)call->data)->syscall_nr; 396 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) 397 return -ENOSYS; 398 mutex_lock(&syscall_trace_lock); 399 if (!tr->sys_refcount_enter) 400 ret = register_trace_sys_enter(ftrace_syscall_enter, tr); 401 if (!ret) { 402 rcu_assign_pointer(tr->enter_syscall_files[num], file); 403 tr->sys_refcount_enter++; 404 } 405 mutex_unlock(&syscall_trace_lock); 406 return ret; 407 } 408 409 static void unreg_event_syscall_enter(struct trace_event_file *file, 410 struct trace_event_call *call) 411 { 412 struct trace_array *tr = file->tr; 413 int num; 414 415 num = ((struct syscall_metadata *)call->data)->syscall_nr; 416 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) 417 return; 418 mutex_lock(&syscall_trace_lock); 419 tr->sys_refcount_enter--; 420 RCU_INIT_POINTER(tr->enter_syscall_files[num], NULL); 421 if (!tr->sys_refcount_enter) 422 unregister_trace_sys_enter(ftrace_syscall_enter, tr); 423 mutex_unlock(&syscall_trace_lock); 424 } 425 426 static int reg_event_syscall_exit(struct trace_event_file *file, 427 struct trace_event_call *call) 428 { 429 struct trace_array *tr = file->tr; 430 int ret = 0; 431 int num; 432 433 num = ((struct syscall_metadata *)call->data)->syscall_nr; 434 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) 435 return -ENOSYS; 436 mutex_lock(&syscall_trace_lock); 437 if (!tr->sys_refcount_exit) 438 ret = register_trace_sys_exit(ftrace_syscall_exit, tr); 439 if (!ret) { 440 rcu_assign_pointer(tr->exit_syscall_files[num], file); 441 tr->sys_refcount_exit++; 442 } 443 mutex_unlock(&syscall_trace_lock); 444 return ret; 445 } 446 447 static void unreg_event_syscall_exit(struct trace_event_file *file, 448 struct trace_event_call *call) 449 { 450 struct trace_array *tr = file->tr; 451 int num; 452 453 num = ((struct syscall_metadata *)call->data)->syscall_nr; 454 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) 455 return; 456 mutex_lock(&syscall_trace_lock); 457 tr->sys_refcount_exit--; 458 RCU_INIT_POINTER(tr->exit_syscall_files[num], NULL); 459 if (!tr->sys_refcount_exit) 460 unregister_trace_sys_exit(ftrace_syscall_exit, tr); 461 mutex_unlock(&syscall_trace_lock); 462 } 463 464 static int __init init_syscall_trace(struct trace_event_call *call) 465 { 466 int id; 467 int num; 468 469 num = ((struct syscall_metadata *)call->data)->syscall_nr; 470 if (num < 0 || num >= NR_syscalls) { 471 pr_debug("syscall %s metadata not mapped, disabling ftrace event\n", 472 ((struct syscall_metadata *)call->data)->name); 473 return -ENOSYS; 474 } 475 476 if (set_syscall_print_fmt(call) < 0) 477 return -ENOMEM; 478 479 id = trace_event_raw_init(call); 480 481 if (id < 0) { 482 free_syscall_print_fmt(call); 483 return id; 484 } 485 486 return id; 487 } 488 489 struct trace_event_functions enter_syscall_print_funcs = { 490 .trace = print_syscall_enter, 491 }; 492 493 struct trace_event_functions exit_syscall_print_funcs = { 494 .trace = print_syscall_exit, 495 }; 496 497 struct trace_event_class __refdata event_class_syscall_enter = { 498 .system = "syscalls", 499 .reg = syscall_enter_register, 500 .define_fields = syscall_enter_define_fields, 501 .get_fields = syscall_get_enter_fields, 502 .raw_init = init_syscall_trace, 503 }; 504 505 struct trace_event_class __refdata event_class_syscall_exit = { 506 .system = "syscalls", 507 .reg = syscall_exit_register, 508 .define_fields = syscall_exit_define_fields, 509 .fields = LIST_HEAD_INIT(event_class_syscall_exit.fields), 510 .raw_init = init_syscall_trace, 511 }; 512 513 unsigned long __init __weak arch_syscall_addr(int nr) 514 { 515 return (unsigned long)sys_call_table[nr]; 516 } 517 518 void __init init_ftrace_syscalls(void) 519 { 520 struct syscall_metadata *meta; 521 unsigned long addr; 522 int i; 523 524 syscalls_metadata = kcalloc(NR_syscalls, sizeof(*syscalls_metadata), 525 GFP_KERNEL); 526 if (!syscalls_metadata) { 527 WARN_ON(1); 528 return; 529 } 530 531 for (i = 0; i < NR_syscalls; i++) { 532 addr = arch_syscall_addr(i); 533 meta = find_syscall_meta(addr); 534 if (!meta) 535 continue; 536 537 meta->syscall_nr = i; 538 syscalls_metadata[i] = meta; 539 } 540 } 541 542 #ifdef CONFIG_PERF_EVENTS 543 544 static DECLARE_BITMAP(enabled_perf_enter_syscalls, NR_syscalls); 545 static DECLARE_BITMAP(enabled_perf_exit_syscalls, NR_syscalls); 546 static int sys_perf_refcount_enter; 547 static int sys_perf_refcount_exit; 548 549 static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id) 550 { 551 struct syscall_metadata *sys_data; 552 struct syscall_trace_enter *rec; 553 struct hlist_head *head; 554 int syscall_nr; 555 int rctx; 556 int size; 557 558 syscall_nr = trace_get_syscall_nr(current, regs); 559 if (syscall_nr < 0 || syscall_nr >= NR_syscalls) 560 return; 561 if (!test_bit(syscall_nr, enabled_perf_enter_syscalls)) 562 return; 563 564 sys_data = syscall_nr_to_meta(syscall_nr); 565 if (!sys_data) 566 return; 567 568 head = this_cpu_ptr(sys_data->enter_event->perf_events); 569 if (hlist_empty(head)) 570 return; 571 572 /* get the size after alignment with the u32 buffer size field */ 573 size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec); 574 size = ALIGN(size + sizeof(u32), sizeof(u64)); 575 size -= sizeof(u32); 576 577 rec = (struct syscall_trace_enter *)perf_trace_buf_prepare(size, 578 sys_data->enter_event->event.type, NULL, &rctx); 579 if (!rec) 580 return; 581 582 rec->nr = syscall_nr; 583 syscall_get_arguments(current, regs, 0, sys_data->nb_args, 584 (unsigned long *)&rec->args); 585 perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL); 586 } 587 588 static int perf_sysenter_enable(struct trace_event_call *call) 589 { 590 int ret = 0; 591 int num; 592 593 num = ((struct syscall_metadata *)call->data)->syscall_nr; 594 595 mutex_lock(&syscall_trace_lock); 596 if (!sys_perf_refcount_enter) 597 ret = register_trace_sys_enter(perf_syscall_enter, NULL); 598 if (ret) { 599 pr_info("event trace: Could not activate" 600 "syscall entry trace point"); 601 } else { 602 set_bit(num, enabled_perf_enter_syscalls); 603 sys_perf_refcount_enter++; 604 } 605 mutex_unlock(&syscall_trace_lock); 606 return ret; 607 } 608 609 static void perf_sysenter_disable(struct trace_event_call *call) 610 { 611 int num; 612 613 num = ((struct syscall_metadata *)call->data)->syscall_nr; 614 615 mutex_lock(&syscall_trace_lock); 616 sys_perf_refcount_enter--; 617 clear_bit(num, enabled_perf_enter_syscalls); 618 if (!sys_perf_refcount_enter) 619 unregister_trace_sys_enter(perf_syscall_enter, NULL); 620 mutex_unlock(&syscall_trace_lock); 621 } 622 623 static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret) 624 { 625 struct syscall_metadata *sys_data; 626 struct syscall_trace_exit *rec; 627 struct hlist_head *head; 628 int syscall_nr; 629 int rctx; 630 int size; 631 632 syscall_nr = trace_get_syscall_nr(current, regs); 633 if (syscall_nr < 0 || syscall_nr >= NR_syscalls) 634 return; 635 if (!test_bit(syscall_nr, enabled_perf_exit_syscalls)) 636 return; 637 638 sys_data = syscall_nr_to_meta(syscall_nr); 639 if (!sys_data) 640 return; 641 642 head = this_cpu_ptr(sys_data->exit_event->perf_events); 643 if (hlist_empty(head)) 644 return; 645 646 /* We can probably do that at build time */ 647 size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64)); 648 size -= sizeof(u32); 649 650 rec = (struct syscall_trace_exit *)perf_trace_buf_prepare(size, 651 sys_data->exit_event->event.type, NULL, &rctx); 652 if (!rec) 653 return; 654 655 rec->nr = syscall_nr; 656 rec->ret = syscall_get_return_value(current, regs); 657 perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL); 658 } 659 660 static int perf_sysexit_enable(struct trace_event_call *call) 661 { 662 int ret = 0; 663 int num; 664 665 num = ((struct syscall_metadata *)call->data)->syscall_nr; 666 667 mutex_lock(&syscall_trace_lock); 668 if (!sys_perf_refcount_exit) 669 ret = register_trace_sys_exit(perf_syscall_exit, NULL); 670 if (ret) { 671 pr_info("event trace: Could not activate" 672 "syscall exit trace point"); 673 } else { 674 set_bit(num, enabled_perf_exit_syscalls); 675 sys_perf_refcount_exit++; 676 } 677 mutex_unlock(&syscall_trace_lock); 678 return ret; 679 } 680 681 static void perf_sysexit_disable(struct trace_event_call *call) 682 { 683 int num; 684 685 num = ((struct syscall_metadata *)call->data)->syscall_nr; 686 687 mutex_lock(&syscall_trace_lock); 688 sys_perf_refcount_exit--; 689 clear_bit(num, enabled_perf_exit_syscalls); 690 if (!sys_perf_refcount_exit) 691 unregister_trace_sys_exit(perf_syscall_exit, NULL); 692 mutex_unlock(&syscall_trace_lock); 693 } 694 695 #endif /* CONFIG_PERF_EVENTS */ 696 697 static int syscall_enter_register(struct trace_event_call *event, 698 enum trace_reg type, void *data) 699 { 700 struct trace_event_file *file = data; 701 702 switch (type) { 703 case TRACE_REG_REGISTER: 704 return reg_event_syscall_enter(file, event); 705 case TRACE_REG_UNREGISTER: 706 unreg_event_syscall_enter(file, event); 707 return 0; 708 709 #ifdef CONFIG_PERF_EVENTS 710 case TRACE_REG_PERF_REGISTER: 711 return perf_sysenter_enable(event); 712 case TRACE_REG_PERF_UNREGISTER: 713 perf_sysenter_disable(event); 714 return 0; 715 case TRACE_REG_PERF_OPEN: 716 case TRACE_REG_PERF_CLOSE: 717 case TRACE_REG_PERF_ADD: 718 case TRACE_REG_PERF_DEL: 719 return 0; 720 #endif 721 } 722 return 0; 723 } 724 725 static int syscall_exit_register(struct trace_event_call *event, 726 enum trace_reg type, void *data) 727 { 728 struct trace_event_file *file = data; 729 730 switch (type) { 731 case TRACE_REG_REGISTER: 732 return reg_event_syscall_exit(file, event); 733 case TRACE_REG_UNREGISTER: 734 unreg_event_syscall_exit(file, event); 735 return 0; 736 737 #ifdef CONFIG_PERF_EVENTS 738 case TRACE_REG_PERF_REGISTER: 739 return perf_sysexit_enable(event); 740 case TRACE_REG_PERF_UNREGISTER: 741 perf_sysexit_disable(event); 742 return 0; 743 case TRACE_REG_PERF_OPEN: 744 case TRACE_REG_PERF_CLOSE: 745 case TRACE_REG_PERF_ADD: 746 case TRACE_REG_PERF_DEL: 747 return 0; 748 #endif 749 } 750 return 0; 751 } 752