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 ftrace_event_call *event, 17 enum trace_reg type, void *data); 18 static int syscall_exit_register(struct ftrace_event_call *event, 19 enum trace_reg type, void *data); 20 21 static struct list_head * 22 syscall_get_enter_fields(struct ftrace_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_seq *s = &iter->seq; 114 struct trace_entry *ent = iter->ent; 115 struct syscall_trace_enter *trace; 116 struct syscall_metadata *entry; 117 int i, ret, syscall; 118 119 trace = (typeof(trace))ent; 120 syscall = trace->nr; 121 entry = syscall_nr_to_meta(syscall); 122 123 if (!entry) 124 goto end; 125 126 if (entry->enter_event->event.type != ent->type) { 127 WARN_ON_ONCE(1); 128 goto end; 129 } 130 131 ret = trace_seq_printf(s, "%s(", entry->name); 132 if (!ret) 133 return TRACE_TYPE_PARTIAL_LINE; 134 135 for (i = 0; i < entry->nb_args; i++) { 136 /* parameter types */ 137 if (trace_flags & TRACE_ITER_VERBOSE) { 138 ret = trace_seq_printf(s, "%s ", entry->types[i]); 139 if (!ret) 140 return TRACE_TYPE_PARTIAL_LINE; 141 } 142 /* parameter values */ 143 ret = trace_seq_printf(s, "%s: %lx%s", entry->args[i], 144 trace->args[i], 145 i == entry->nb_args - 1 ? "" : ", "); 146 if (!ret) 147 return TRACE_TYPE_PARTIAL_LINE; 148 } 149 150 ret = trace_seq_putc(s, ')'); 151 if (!ret) 152 return TRACE_TYPE_PARTIAL_LINE; 153 154 end: 155 ret = trace_seq_putc(s, '\n'); 156 if (!ret) 157 return TRACE_TYPE_PARTIAL_LINE; 158 159 return TRACE_TYPE_HANDLED; 160 } 161 162 static enum print_line_t 163 print_syscall_exit(struct trace_iterator *iter, int flags, 164 struct trace_event *event) 165 { 166 struct trace_seq *s = &iter->seq; 167 struct trace_entry *ent = iter->ent; 168 struct syscall_trace_exit *trace; 169 int syscall; 170 struct syscall_metadata *entry; 171 int ret; 172 173 trace = (typeof(trace))ent; 174 syscall = trace->nr; 175 entry = syscall_nr_to_meta(syscall); 176 177 if (!entry) { 178 trace_seq_putc(s, '\n'); 179 return TRACE_TYPE_HANDLED; 180 } 181 182 if (entry->exit_event->event.type != ent->type) { 183 WARN_ON_ONCE(1); 184 return TRACE_TYPE_UNHANDLED; 185 } 186 187 ret = trace_seq_printf(s, "%s -> 0x%lx\n", entry->name, 188 trace->ret); 189 if (!ret) 190 return TRACE_TYPE_PARTIAL_LINE; 191 192 return TRACE_TYPE_HANDLED; 193 } 194 195 extern char *__bad_type_size(void); 196 197 #define SYSCALL_FIELD(type, name) \ 198 sizeof(type) != sizeof(trace.name) ? \ 199 __bad_type_size() : \ 200 #type, #name, offsetof(typeof(trace), name), \ 201 sizeof(trace.name), is_signed_type(type) 202 203 static int __init 204 __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len) 205 { 206 int i; 207 int pos = 0; 208 209 /* When len=0, we just calculate the needed length */ 210 #define LEN_OR_ZERO (len ? len - pos : 0) 211 212 pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); 213 for (i = 0; i < entry->nb_args; i++) { 214 pos += snprintf(buf + pos, LEN_OR_ZERO, "%s: 0x%%0%zulx%s", 215 entry->args[i], sizeof(unsigned long), 216 i == entry->nb_args - 1 ? "" : ", "); 217 } 218 pos += snprintf(buf + pos, LEN_OR_ZERO, "\""); 219 220 for (i = 0; i < entry->nb_args; i++) { 221 pos += snprintf(buf + pos, LEN_OR_ZERO, 222 ", ((unsigned long)(REC->%s))", entry->args[i]); 223 } 224 225 #undef LEN_OR_ZERO 226 227 /* return the length of print_fmt */ 228 return pos; 229 } 230 231 static int __init set_syscall_print_fmt(struct ftrace_event_call *call) 232 { 233 char *print_fmt; 234 int len; 235 struct syscall_metadata *entry = call->data; 236 237 if (entry->enter_event != call) { 238 call->print_fmt = "\"0x%lx\", REC->ret"; 239 return 0; 240 } 241 242 /* First: called with 0 length to calculate the needed length */ 243 len = __set_enter_print_fmt(entry, NULL, 0); 244 245 print_fmt = kmalloc(len + 1, GFP_KERNEL); 246 if (!print_fmt) 247 return -ENOMEM; 248 249 /* Second: actually write the @print_fmt */ 250 __set_enter_print_fmt(entry, print_fmt, len + 1); 251 call->print_fmt = print_fmt; 252 253 return 0; 254 } 255 256 static void __init free_syscall_print_fmt(struct ftrace_event_call *call) 257 { 258 struct syscall_metadata *entry = call->data; 259 260 if (entry->enter_event == call) 261 kfree(call->print_fmt); 262 } 263 264 static int __init syscall_enter_define_fields(struct ftrace_event_call *call) 265 { 266 struct syscall_trace_enter trace; 267 struct syscall_metadata *meta = call->data; 268 int ret; 269 int i; 270 int offset = offsetof(typeof(trace), args); 271 272 ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER); 273 if (ret) 274 return ret; 275 276 for (i = 0; i < meta->nb_args; i++) { 277 ret = trace_define_field(call, meta->types[i], 278 meta->args[i], offset, 279 sizeof(unsigned long), 0, 280 FILTER_OTHER); 281 offset += sizeof(unsigned long); 282 } 283 284 return ret; 285 } 286 287 static int __init syscall_exit_define_fields(struct ftrace_event_call *call) 288 { 289 struct syscall_trace_exit trace; 290 int ret; 291 292 ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER); 293 if (ret) 294 return ret; 295 296 ret = trace_define_field(call, SYSCALL_FIELD(long, ret), 297 FILTER_OTHER); 298 299 return ret; 300 } 301 302 static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id) 303 { 304 struct trace_array *tr = data; 305 struct ftrace_event_file *ftrace_file; 306 struct syscall_trace_enter *entry; 307 struct syscall_metadata *sys_data; 308 struct ring_buffer_event *event; 309 struct ring_buffer *buffer; 310 unsigned long irq_flags; 311 int pc; 312 int syscall_nr; 313 int size; 314 315 syscall_nr = trace_get_syscall_nr(current, regs); 316 if (syscall_nr < 0) 317 return; 318 319 /* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE) */ 320 ftrace_file = rcu_dereference_sched(tr->enter_syscall_files[syscall_nr]); 321 if (!ftrace_file) 322 return; 323 324 if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags)) 325 return; 326 327 sys_data = syscall_nr_to_meta(syscall_nr); 328 if (!sys_data) 329 return; 330 331 size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args; 332 333 local_save_flags(irq_flags); 334 pc = preempt_count(); 335 336 buffer = tr->trace_buffer.buffer; 337 event = trace_buffer_lock_reserve(buffer, 338 sys_data->enter_event->event.type, size, irq_flags, pc); 339 if (!event) 340 return; 341 342 entry = ring_buffer_event_data(event); 343 entry->nr = syscall_nr; 344 syscall_get_arguments(current, regs, 0, sys_data->nb_args, entry->args); 345 346 if (!filter_check_discard(ftrace_file, entry, buffer, event)) 347 trace_current_buffer_unlock_commit(buffer, event, 348 irq_flags, pc); 349 } 350 351 static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret) 352 { 353 struct trace_array *tr = data; 354 struct ftrace_event_file *ftrace_file; 355 struct syscall_trace_exit *entry; 356 struct syscall_metadata *sys_data; 357 struct ring_buffer_event *event; 358 struct ring_buffer *buffer; 359 unsigned long irq_flags; 360 int pc; 361 int syscall_nr; 362 363 syscall_nr = trace_get_syscall_nr(current, regs); 364 if (syscall_nr < 0) 365 return; 366 367 /* Here we're inside tp handler's rcu_read_lock_sched (__DO_TRACE()) */ 368 ftrace_file = rcu_dereference_sched(tr->exit_syscall_files[syscall_nr]); 369 if (!ftrace_file) 370 return; 371 372 if (test_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &ftrace_file->flags)) 373 return; 374 375 sys_data = syscall_nr_to_meta(syscall_nr); 376 if (!sys_data) 377 return; 378 379 local_save_flags(irq_flags); 380 pc = preempt_count(); 381 382 buffer = tr->trace_buffer.buffer; 383 event = trace_buffer_lock_reserve(buffer, 384 sys_data->exit_event->event.type, sizeof(*entry), 385 irq_flags, pc); 386 if (!event) 387 return; 388 389 entry = ring_buffer_event_data(event); 390 entry->nr = syscall_nr; 391 entry->ret = syscall_get_return_value(current, regs); 392 393 if (!filter_check_discard(ftrace_file, entry, buffer, event)) 394 trace_current_buffer_unlock_commit(buffer, event, 395 irq_flags, pc); 396 } 397 398 static int reg_event_syscall_enter(struct ftrace_event_file *file, 399 struct ftrace_event_call *call) 400 { 401 struct trace_array *tr = file->tr; 402 int ret = 0; 403 int num; 404 405 num = ((struct syscall_metadata *)call->data)->syscall_nr; 406 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) 407 return -ENOSYS; 408 mutex_lock(&syscall_trace_lock); 409 if (!tr->sys_refcount_enter) 410 ret = register_trace_sys_enter(ftrace_syscall_enter, tr); 411 if (!ret) { 412 rcu_assign_pointer(tr->enter_syscall_files[num], file); 413 tr->sys_refcount_enter++; 414 } 415 mutex_unlock(&syscall_trace_lock); 416 return ret; 417 } 418 419 static void unreg_event_syscall_enter(struct ftrace_event_file *file, 420 struct ftrace_event_call *call) 421 { 422 struct trace_array *tr = file->tr; 423 int num; 424 425 num = ((struct syscall_metadata *)call->data)->syscall_nr; 426 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) 427 return; 428 mutex_lock(&syscall_trace_lock); 429 tr->sys_refcount_enter--; 430 rcu_assign_pointer(tr->enter_syscall_files[num], NULL); 431 if (!tr->sys_refcount_enter) 432 unregister_trace_sys_enter(ftrace_syscall_enter, tr); 433 mutex_unlock(&syscall_trace_lock); 434 /* 435 * Callers expect the event to be completely disabled on 436 * return, so wait for current handlers to finish. 437 */ 438 synchronize_sched(); 439 } 440 441 static int reg_event_syscall_exit(struct ftrace_event_file *file, 442 struct ftrace_event_call *call) 443 { 444 struct trace_array *tr = file->tr; 445 int ret = 0; 446 int num; 447 448 num = ((struct syscall_metadata *)call->data)->syscall_nr; 449 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) 450 return -ENOSYS; 451 mutex_lock(&syscall_trace_lock); 452 if (!tr->sys_refcount_exit) 453 ret = register_trace_sys_exit(ftrace_syscall_exit, tr); 454 if (!ret) { 455 rcu_assign_pointer(tr->exit_syscall_files[num], file); 456 tr->sys_refcount_exit++; 457 } 458 mutex_unlock(&syscall_trace_lock); 459 return ret; 460 } 461 462 static void unreg_event_syscall_exit(struct ftrace_event_file *file, 463 struct ftrace_event_call *call) 464 { 465 struct trace_array *tr = file->tr; 466 int num; 467 468 num = ((struct syscall_metadata *)call->data)->syscall_nr; 469 if (WARN_ON_ONCE(num < 0 || num >= NR_syscalls)) 470 return; 471 mutex_lock(&syscall_trace_lock); 472 tr->sys_refcount_exit--; 473 rcu_assign_pointer(tr->exit_syscall_files[num], NULL); 474 if (!tr->sys_refcount_exit) 475 unregister_trace_sys_exit(ftrace_syscall_exit, tr); 476 mutex_unlock(&syscall_trace_lock); 477 /* 478 * Callers expect the event to be completely disabled on 479 * return, so wait for current handlers to finish. 480 */ 481 synchronize_sched(); 482 } 483 484 static int __init init_syscall_trace(struct ftrace_event_call *call) 485 { 486 int id; 487 int num; 488 489 num = ((struct syscall_metadata *)call->data)->syscall_nr; 490 if (num < 0 || num >= NR_syscalls) { 491 pr_debug("syscall %s metadata not mapped, disabling ftrace event\n", 492 ((struct syscall_metadata *)call->data)->name); 493 return -ENOSYS; 494 } 495 496 if (set_syscall_print_fmt(call) < 0) 497 return -ENOMEM; 498 499 id = trace_event_raw_init(call); 500 501 if (id < 0) { 502 free_syscall_print_fmt(call); 503 return id; 504 } 505 506 return id; 507 } 508 509 struct trace_event_functions enter_syscall_print_funcs = { 510 .trace = print_syscall_enter, 511 }; 512 513 struct trace_event_functions exit_syscall_print_funcs = { 514 .trace = print_syscall_exit, 515 }; 516 517 struct ftrace_event_class __refdata event_class_syscall_enter = { 518 .system = "syscalls", 519 .reg = syscall_enter_register, 520 .define_fields = syscall_enter_define_fields, 521 .get_fields = syscall_get_enter_fields, 522 .raw_init = init_syscall_trace, 523 }; 524 525 struct ftrace_event_class __refdata event_class_syscall_exit = { 526 .system = "syscalls", 527 .reg = syscall_exit_register, 528 .define_fields = syscall_exit_define_fields, 529 .fields = LIST_HEAD_INIT(event_class_syscall_exit.fields), 530 .raw_init = init_syscall_trace, 531 }; 532 533 unsigned long __init __weak arch_syscall_addr(int nr) 534 { 535 return (unsigned long)sys_call_table[nr]; 536 } 537 538 static int __init init_ftrace_syscalls(void) 539 { 540 struct syscall_metadata *meta; 541 unsigned long addr; 542 int i; 543 544 syscalls_metadata = kcalloc(NR_syscalls, sizeof(*syscalls_metadata), 545 GFP_KERNEL); 546 if (!syscalls_metadata) { 547 WARN_ON(1); 548 return -ENOMEM; 549 } 550 551 for (i = 0; i < NR_syscalls; i++) { 552 addr = arch_syscall_addr(i); 553 meta = find_syscall_meta(addr); 554 if (!meta) 555 continue; 556 557 meta->syscall_nr = i; 558 syscalls_metadata[i] = meta; 559 } 560 561 return 0; 562 } 563 early_initcall(init_ftrace_syscalls); 564 565 #ifdef CONFIG_PERF_EVENTS 566 567 static DECLARE_BITMAP(enabled_perf_enter_syscalls, NR_syscalls); 568 static DECLARE_BITMAP(enabled_perf_exit_syscalls, NR_syscalls); 569 static int sys_perf_refcount_enter; 570 static int sys_perf_refcount_exit; 571 572 static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id) 573 { 574 struct syscall_metadata *sys_data; 575 struct syscall_trace_enter *rec; 576 struct hlist_head *head; 577 int syscall_nr; 578 int rctx; 579 int size; 580 581 syscall_nr = trace_get_syscall_nr(current, regs); 582 if (syscall_nr < 0) 583 return; 584 if (!test_bit(syscall_nr, enabled_perf_enter_syscalls)) 585 return; 586 587 sys_data = syscall_nr_to_meta(syscall_nr); 588 if (!sys_data) 589 return; 590 591 head = this_cpu_ptr(sys_data->enter_event->perf_events); 592 if (hlist_empty(head)) 593 return; 594 595 /* get the size after alignment with the u32 buffer size field */ 596 size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec); 597 size = ALIGN(size + sizeof(u32), sizeof(u64)); 598 size -= sizeof(u32); 599 600 rec = (struct syscall_trace_enter *)perf_trace_buf_prepare(size, 601 sys_data->enter_event->event.type, regs, &rctx); 602 if (!rec) 603 return; 604 605 rec->nr = syscall_nr; 606 syscall_get_arguments(current, regs, 0, sys_data->nb_args, 607 (unsigned long *)&rec->args); 608 perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL); 609 } 610 611 static int perf_sysenter_enable(struct ftrace_event_call *call) 612 { 613 int ret = 0; 614 int num; 615 616 num = ((struct syscall_metadata *)call->data)->syscall_nr; 617 618 mutex_lock(&syscall_trace_lock); 619 if (!sys_perf_refcount_enter) 620 ret = register_trace_sys_enter(perf_syscall_enter, NULL); 621 if (ret) { 622 pr_info("event trace: Could not activate" 623 "syscall entry trace point"); 624 } else { 625 set_bit(num, enabled_perf_enter_syscalls); 626 sys_perf_refcount_enter++; 627 } 628 mutex_unlock(&syscall_trace_lock); 629 return ret; 630 } 631 632 static void perf_sysenter_disable(struct ftrace_event_call *call) 633 { 634 int num; 635 636 num = ((struct syscall_metadata *)call->data)->syscall_nr; 637 638 mutex_lock(&syscall_trace_lock); 639 sys_perf_refcount_enter--; 640 clear_bit(num, enabled_perf_enter_syscalls); 641 if (!sys_perf_refcount_enter) 642 unregister_trace_sys_enter(perf_syscall_enter, NULL); 643 mutex_unlock(&syscall_trace_lock); 644 } 645 646 static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret) 647 { 648 struct syscall_metadata *sys_data; 649 struct syscall_trace_exit *rec; 650 struct hlist_head *head; 651 int syscall_nr; 652 int rctx; 653 int size; 654 655 syscall_nr = trace_get_syscall_nr(current, regs); 656 if (syscall_nr < 0) 657 return; 658 if (!test_bit(syscall_nr, enabled_perf_exit_syscalls)) 659 return; 660 661 sys_data = syscall_nr_to_meta(syscall_nr); 662 if (!sys_data) 663 return; 664 665 head = this_cpu_ptr(sys_data->exit_event->perf_events); 666 if (hlist_empty(head)) 667 return; 668 669 /* We can probably do that at build time */ 670 size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64)); 671 size -= sizeof(u32); 672 673 rec = (struct syscall_trace_exit *)perf_trace_buf_prepare(size, 674 sys_data->exit_event->event.type, regs, &rctx); 675 if (!rec) 676 return; 677 678 rec->nr = syscall_nr; 679 rec->ret = syscall_get_return_value(current, regs); 680 perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL); 681 } 682 683 static int perf_sysexit_enable(struct ftrace_event_call *call) 684 { 685 int ret = 0; 686 int num; 687 688 num = ((struct syscall_metadata *)call->data)->syscall_nr; 689 690 mutex_lock(&syscall_trace_lock); 691 if (!sys_perf_refcount_exit) 692 ret = register_trace_sys_exit(perf_syscall_exit, NULL); 693 if (ret) { 694 pr_info("event trace: Could not activate" 695 "syscall exit trace point"); 696 } else { 697 set_bit(num, enabled_perf_exit_syscalls); 698 sys_perf_refcount_exit++; 699 } 700 mutex_unlock(&syscall_trace_lock); 701 return ret; 702 } 703 704 static void perf_sysexit_disable(struct ftrace_event_call *call) 705 { 706 int num; 707 708 num = ((struct syscall_metadata *)call->data)->syscall_nr; 709 710 mutex_lock(&syscall_trace_lock); 711 sys_perf_refcount_exit--; 712 clear_bit(num, enabled_perf_exit_syscalls); 713 if (!sys_perf_refcount_exit) 714 unregister_trace_sys_exit(perf_syscall_exit, NULL); 715 mutex_unlock(&syscall_trace_lock); 716 } 717 718 #endif /* CONFIG_PERF_EVENTS */ 719 720 static int syscall_enter_register(struct ftrace_event_call *event, 721 enum trace_reg type, void *data) 722 { 723 struct ftrace_event_file *file = data; 724 725 switch (type) { 726 case TRACE_REG_REGISTER: 727 return reg_event_syscall_enter(file, event); 728 case TRACE_REG_UNREGISTER: 729 unreg_event_syscall_enter(file, event); 730 return 0; 731 732 #ifdef CONFIG_PERF_EVENTS 733 case TRACE_REG_PERF_REGISTER: 734 return perf_sysenter_enable(event); 735 case TRACE_REG_PERF_UNREGISTER: 736 perf_sysenter_disable(event); 737 return 0; 738 case TRACE_REG_PERF_OPEN: 739 case TRACE_REG_PERF_CLOSE: 740 case TRACE_REG_PERF_ADD: 741 case TRACE_REG_PERF_DEL: 742 return 0; 743 #endif 744 } 745 return 0; 746 } 747 748 static int syscall_exit_register(struct ftrace_event_call *event, 749 enum trace_reg type, void *data) 750 { 751 struct ftrace_event_file *file = data; 752 753 switch (type) { 754 case TRACE_REG_REGISTER: 755 return reg_event_syscall_exit(file, event); 756 case TRACE_REG_UNREGISTER: 757 unreg_event_syscall_exit(file, event); 758 return 0; 759 760 #ifdef CONFIG_PERF_EVENTS 761 case TRACE_REG_PERF_REGISTER: 762 return perf_sysexit_enable(event); 763 case TRACE_REG_PERF_UNREGISTER: 764 perf_sysexit_disable(event); 765 return 0; 766 case TRACE_REG_PERF_OPEN: 767 case TRACE_REG_PERF_CLOSE: 768 case TRACE_REG_PERF_ADD: 769 case TRACE_REG_PERF_DEL: 770 return 0; 771 #endif 772 } 773 return 0; 774 } 775