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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 | // SPDX-License-Identifier: GPL-2.0 /* * ring buffer based function tracer * * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> * * Based on code from the latency_tracer, that is: * * Copyright (C) 2004-2006 Ingo Molnar * Copyright (C) 2004 Nadia Yvette Chambers */ #include <linux/ring_buffer.h> #include <linux/debugfs.h> #include <linux/uaccess.h> #include <linux/ftrace.h> #include <linux/slab.h> #include <linux/fs.h> #include "trace.h" static void tracing_start_function_trace(struct trace_array *tr); static void tracing_stop_function_trace(struct trace_array *tr); static void function_trace_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs); static void function_stack_trace_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs); static void function_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs); static void function_stack_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs); static struct tracer_flags func_flags; /* Our option */ enum { TRACE_FUNC_NO_OPTS = 0x0, /* No flags set. */ TRACE_FUNC_OPT_STACK = 0x1, TRACE_FUNC_OPT_NO_REPEATS = 0x2, /* Update this to next highest bit. */ TRACE_FUNC_OPT_HIGHEST_BIT = 0x4 }; #define TRACE_FUNC_OPT_MASK (TRACE_FUNC_OPT_HIGHEST_BIT - 1) int ftrace_allocate_ftrace_ops(struct trace_array *tr) { struct ftrace_ops *ops; /* The top level array uses the "global_ops" */ if (tr->flags & TRACE_ARRAY_FL_GLOBAL) return 0; ops = kzalloc(sizeof(*ops), GFP_KERNEL); if (!ops) return -ENOMEM; /* Currently only the non stack version is supported */ ops->func = function_trace_call; ops->flags = FTRACE_OPS_FL_PID; tr->ops = ops; ops->private = tr; return 0; } void ftrace_free_ftrace_ops(struct trace_array *tr) { kfree(tr->ops); tr->ops = NULL; } int ftrace_create_function_files(struct trace_array *tr, struct dentry *parent) { /* * The top level array uses the "global_ops", and the files are * created on boot up. */ if (tr->flags & TRACE_ARRAY_FL_GLOBAL) return 0; if (!tr->ops) return -EINVAL; ftrace_create_filter_files(tr->ops, parent); return 0; } void ftrace_destroy_function_files(struct trace_array *tr) { ftrace_destroy_filter_files(tr->ops); ftrace_free_ftrace_ops(tr); } static ftrace_func_t select_trace_function(u32 flags_val) { switch (flags_val & TRACE_FUNC_OPT_MASK) { case TRACE_FUNC_NO_OPTS: return function_trace_call; case TRACE_FUNC_OPT_STACK: return function_stack_trace_call; case TRACE_FUNC_OPT_NO_REPEATS: return function_no_repeats_trace_call; case TRACE_FUNC_OPT_STACK | TRACE_FUNC_OPT_NO_REPEATS: return function_stack_no_repeats_trace_call; default: return NULL; } } static bool handle_func_repeats(struct trace_array *tr, u32 flags_val) { if (!tr->last_func_repeats && (flags_val & TRACE_FUNC_OPT_NO_REPEATS)) { tr->last_func_repeats = alloc_percpu(struct trace_func_repeats); if (!tr->last_func_repeats) return false; } return true; } static int function_trace_init(struct trace_array *tr) { ftrace_func_t func; /* * Instance trace_arrays get their ops allocated * at instance creation. Unless it failed * the allocation. */ if (!tr->ops) return -ENOMEM; func = select_trace_function(func_flags.val); if (!func) return -EINVAL; if (!handle_func_repeats(tr, func_flags.val)) return -ENOMEM; ftrace_init_array_ops(tr, func); tr->array_buffer.cpu = raw_smp_processor_id(); tracing_start_cmdline_record(); tracing_start_function_trace(tr); return 0; } static void function_trace_reset(struct trace_array *tr) { tracing_stop_function_trace(tr); tracing_stop_cmdline_record(); ftrace_reset_array_ops(tr); } static void function_trace_start(struct trace_array *tr) { tracing_reset_online_cpus(&tr->array_buffer); } static void function_trace_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs) { struct trace_array *tr = op->private; struct trace_array_cpu *data; unsigned int trace_ctx; int bit; int cpu; if (unlikely(!tr->function_enabled)) return; bit = ftrace_test_recursion_trylock(ip, parent_ip); if (bit < 0) return; trace_ctx = tracing_gen_ctx(); cpu = smp_processor_id(); data = per_cpu_ptr(tr->array_buffer.data, cpu); if (!atomic_read(&data->disabled)) trace_function(tr, ip, parent_ip, trace_ctx); ftrace_test_recursion_unlock(bit); } #ifdef CONFIG_UNWINDER_ORC /* * Skip 2: * * function_stack_trace_call() * ftrace_call() */ #define STACK_SKIP 2 #else /* * Skip 3: * __trace_stack() * function_stack_trace_call() * ftrace_call() */ #define STACK_SKIP 3 #endif static void function_stack_trace_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs) { struct trace_array *tr = op->private; struct trace_array_cpu *data; unsigned long flags; long disabled; int cpu; unsigned int trace_ctx; if (unlikely(!tr->function_enabled)) return; /* * Need to use raw, since this must be called before the * recursive protection is performed. */ local_irq_save(flags); cpu = raw_smp_processor_id(); data = per_cpu_ptr(tr->array_buffer.data, cpu); disabled = atomic_inc_return(&data->disabled); if (likely(disabled == 1)) { trace_ctx = tracing_gen_ctx_flags(flags); trace_function(tr, ip, parent_ip, trace_ctx); __trace_stack(tr, trace_ctx, STACK_SKIP); } atomic_dec(&data->disabled); local_irq_restore(flags); } static inline bool is_repeat_check(struct trace_array *tr, struct trace_func_repeats *last_info, unsigned long ip, unsigned long parent_ip) { if (last_info->ip == ip && last_info->parent_ip == parent_ip && last_info->count < U16_MAX) { last_info->ts_last_call = ring_buffer_time_stamp(tr->array_buffer.buffer); last_info->count++; return true; } return false; } static inline void process_repeats(struct trace_array *tr, unsigned long ip, unsigned long parent_ip, struct trace_func_repeats *last_info, unsigned int trace_ctx) { if (last_info->count) { trace_last_func_repeats(tr, last_info, trace_ctx); last_info->count = 0; } last_info->ip = ip; last_info->parent_ip = parent_ip; } static void function_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs) { struct trace_func_repeats *last_info; struct trace_array *tr = op->private; struct trace_array_cpu *data; unsigned int trace_ctx; unsigned long flags; int bit; int cpu; if (unlikely(!tr->function_enabled)) return; bit = ftrace_test_recursion_trylock(ip, parent_ip); if (bit < 0) return; cpu = smp_processor_id(); data = per_cpu_ptr(tr->array_buffer.data, cpu); if (atomic_read(&data->disabled)) goto out; /* * An interrupt may happen at any place here. But as far as I can see, * the only damage that this can cause is to mess up the repetition * counter without valuable data being lost. * TODO: think about a solution that is better than just hoping to be * lucky. */ last_info = per_cpu_ptr(tr->last_func_repeats, cpu); if (is_repeat_check(tr, last_info, ip, parent_ip)) goto out; local_save_flags(flags); trace_ctx = tracing_gen_ctx_flags(flags); process_repeats(tr, ip, parent_ip, last_info, trace_ctx); trace_function(tr, ip, parent_ip, trace_ctx); out: ftrace_test_recursion_unlock(bit); } static void function_stack_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs) { struct trace_func_repeats *last_info; struct trace_array *tr = op->private; struct trace_array_cpu *data; unsigned long flags; long disabled; int cpu; unsigned int trace_ctx; if (unlikely(!tr->function_enabled)) return; /* * Need to use raw, since this must be called before the * recursive protection is performed. */ local_irq_save(flags); cpu = raw_smp_processor_id(); data = per_cpu_ptr(tr->array_buffer.data, cpu); disabled = atomic_inc_return(&data->disabled); if (likely(disabled == 1)) { last_info = per_cpu_ptr(tr->last_func_repeats, cpu); if (is_repeat_check(tr, last_info, ip, parent_ip)) goto out; trace_ctx = tracing_gen_ctx_flags(flags); process_repeats(tr, ip, parent_ip, last_info, trace_ctx); trace_function(tr, ip, parent_ip, trace_ctx); __trace_stack(tr, trace_ctx, STACK_SKIP); } out: atomic_dec(&data->disabled); local_irq_restore(flags); } static struct tracer_opt func_opts[] = { #ifdef CONFIG_STACKTRACE { TRACER_OPT(func_stack_trace, TRACE_FUNC_OPT_STACK) }, #endif { TRACER_OPT(func-no-repeats, TRACE_FUNC_OPT_NO_REPEATS) }, { } /* Always set a last empty entry */ }; static struct tracer_flags func_flags = { .val = TRACE_FUNC_NO_OPTS, /* By default: all flags disabled */ .opts = func_opts }; static void tracing_start_function_trace(struct trace_array *tr) { tr->function_enabled = 0; register_ftrace_function(tr->ops); tr->function_enabled = 1; } static void tracing_stop_function_trace(struct trace_array *tr) { tr->function_enabled = 0; unregister_ftrace_function(tr->ops); } static struct tracer function_trace; static int func_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) { ftrace_func_t func; u32 new_flags; /* Do nothing if already set. */ if (!!set == !!(func_flags.val & bit)) return 0; /* We can change this flag only when not running. */ if (tr->current_trace != &function_trace) return 0; new_flags = (func_flags.val & ~bit) | (set ? bit : 0); func = select_trace_function(new_flags); if (!func) return -EINVAL; /* Check if there's anything to change. */ if (tr->ops->func == func) return 0; if (!handle_func_repeats(tr, new_flags)) return -ENOMEM; unregister_ftrace_function(tr->ops); tr->ops->func = func; register_ftrace_function(tr->ops); return 0; } static struct tracer function_trace __tracer_data = { .name = "function", .init = function_trace_init, .reset = function_trace_reset, .start = function_trace_start, .flags = &func_flags, .set_flag = func_set_flag, .allow_instances = true, #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_function, #endif }; #ifdef CONFIG_DYNAMIC_FTRACE static void update_traceon_count(struct ftrace_probe_ops *ops, unsigned long ip, struct trace_array *tr, bool on, void *data) { struct ftrace_func_mapper *mapper = data; long *count; long old_count; /* * Tracing gets disabled (or enabled) once per count. * This function can be called at the same time on multiple CPUs. * It is fine if both disable (or enable) tracing, as disabling * (or enabling) the second time doesn't do anything as the * state of the tracer is already disabled (or enabled). * What needs to be synchronized in this case is that the count * only gets decremented once, even if the tracer is disabled * (or enabled) twice, as the second one is really a nop. * * The memory barriers guarantee that we only decrement the * counter once. First the count is read to a local variable * and a read barrier is used to make sure that it is loaded * before checking if the tracer is in the state we want. * If the tracer is not in the state we want, then the count * is guaranteed to be the old count. * * Next the tracer is set to the state we want (disabled or enabled) * then a write memory barrier is used to make sure that * the new state is visible before changing the counter by * one minus the old counter. This guarantees that another CPU * executing this code will see the new state before seeing * the new counter value, and would not do anything if the new * counter is seen. * * Note, there is no synchronization between this and a user * setting the tracing_on file. But we currently don't care * about that. */ count = (long *)ftrace_func_mapper_find_ip(mapper, ip); old_count = *count; if (old_count <= 0) return; /* Make sure we see count before checking tracing state */ smp_rmb(); if (on == !!tracer_tracing_is_on(tr)) return; if (on) tracer_tracing_on(tr); else tracer_tracing_off(tr); /* Make sure tracing state is visible before updating count */ smp_wmb(); *count = old_count - 1; } static void ftrace_traceon_count(unsigned long ip, unsigned long parent_ip, struct trace_array *tr, struct ftrace_probe_ops *ops, void *data) { update_traceon_count(ops, ip, tr, 1, data); } static void ftrace_traceoff_count(unsigned long ip, unsigned long parent_ip, struct trace_array *tr, struct ftrace_probe_ops *ops, void *data) { update_traceon_count(ops, ip, tr, 0, data); } static void ftrace_traceon(unsigned long ip, unsigned long parent_ip, struct trace_array *tr, struct ftrace_probe_ops *ops, void *data) { if (tracer_tracing_is_on(tr)) return; tracer_tracing_on(tr); } static void ftrace_traceoff(unsigned long ip, unsigned long parent_ip, struct trace_array *tr, struct ftrace_probe_ops *ops, void *data) { if (!tracer_tracing_is_on(tr)) return; tracer_tracing_off(tr); } #ifdef CONFIG_UNWINDER_ORC /* * Skip 3: * * function_trace_probe_call() * ftrace_ops_assist_func() * ftrace_call() */ #define FTRACE_STACK_SKIP 3 #else /* * Skip 5: * * __trace_stack() * ftrace_stacktrace() * function_trace_probe_call() * ftrace_ops_assist_func() * ftrace_call() */ #define FTRACE_STACK_SKIP 5 #endif static __always_inline void trace_stack(struct trace_array *tr) { unsigned int trace_ctx; trace_ctx = tracing_gen_ctx(); __trace_stack(tr, trace_ctx, FTRACE_STACK_SKIP); } static void ftrace_stacktrace(unsigned long ip, unsigned long parent_ip, struct trace_array *tr, struct ftrace_probe_ops *ops, void *data) { trace_stack(tr); } static void ftrace_stacktrace_count(unsigned long ip, unsigned long parent_ip, struct trace_array *tr, struct ftrace_probe_ops *ops, void *data) { struct ftrace_func_mapper *mapper = data; long *count; long old_count; long new_count; if (!tracing_is_on()) return; /* unlimited? */ if (!mapper) { trace_stack(tr); return; } count = (long *)ftrace_func_mapper_find_ip(mapper, ip); /* * Stack traces should only execute the number of times the * user specified in the counter. */ do { old_count = *count; if (!old_count) return; new_count = old_count - 1; new_count = cmpxchg(count, old_count, new_count); if (new_count == old_count) trace_stack(tr); if (!tracing_is_on()) return; } while (new_count != old_count); } static int update_count(struct ftrace_probe_ops *ops, unsigned long ip, void *data) { struct ftrace_func_mapper *mapper = data; long *count = NULL; if (mapper) count = (long *)ftrace_func_mapper_find_ip(mapper, ip); if (count) { if (*count <= 0) return 0; (*count)--; } return 1; } static void ftrace_dump_probe(unsigned long ip, unsigned long parent_ip, struct trace_array *tr, struct ftrace_probe_ops *ops, void *data) { if (update_count(ops, ip, data)) ftrace_dump(DUMP_ALL); } /* Only dump the current CPU buffer. */ static void ftrace_cpudump_probe(unsigned long ip, unsigned long parent_ip, struct trace_array *tr, struct ftrace_probe_ops *ops, void *data) { if (update_count(ops, ip, data)) ftrace_dump(DUMP_ORIG); } static int ftrace_probe_print(const char *name, struct seq_file *m, unsigned long ip, struct ftrace_probe_ops *ops, void *data) { struct ftrace_func_mapper *mapper = data; long *count = NULL; seq_printf(m, "%ps:%s", (void *)ip, name); if (mapper) count = (long *)ftrace_func_mapper_find_ip(mapper, ip); if (count) seq_printf(m, ":count=%ld\n", *count); else seq_puts(m, ":unlimited\n"); return 0; } static int ftrace_traceon_print(struct seq_file *m, unsigned long ip, struct ftrace_probe_ops *ops, void *data) { return ftrace_probe_print("traceon", m, ip, ops, data); } static int ftrace_traceoff_print(struct seq_file *m, unsigned long ip, struct ftrace_probe_ops *ops, void *data) { return ftrace_probe_print("traceoff", m, ip, ops, data); } static int ftrace_stacktrace_print(struct seq_file *m, unsigned long ip, struct ftrace_probe_ops *ops, void *data) { return ftrace_probe_print("stacktrace", m, ip, ops, data); } static int ftrace_dump_print(struct seq_file *m, unsigned long ip, struct ftrace_probe_ops *ops, void *data) { return ftrace_probe_print("dump", m, ip, ops, data); } static int ftrace_cpudump_print(struct seq_file *m, unsigned long ip, struct ftrace_probe_ops *ops, void *data) { return ftrace_probe_print("cpudump", m, ip, ops, data); } static int ftrace_count_init(struct ftrace_probe_ops *ops, struct trace_array *tr, unsigned long ip, void *init_data, void **data) { struct ftrace_func_mapper *mapper = *data; if (!mapper) { mapper = allocate_ftrace_func_mapper(); if (!mapper) return -ENOMEM; *data = mapper; } return ftrace_func_mapper_add_ip(mapper, ip, init_data); } static void ftrace_count_free(struct ftrace_probe_ops *ops, struct trace_array *tr, unsigned long ip, void *data) { struct ftrace_func_mapper *mapper = data; if (!ip) { free_ftrace_func_mapper(mapper, NULL); return; } ftrace_func_mapper_remove_ip(mapper, ip); } static struct ftrace_probe_ops traceon_count_probe_ops = { .func = ftrace_traceon_count, .print = ftrace_traceon_print, .init = ftrace_count_init, .free = ftrace_count_free, }; static struct ftrace_probe_ops traceoff_count_probe_ops = { .func = ftrace_traceoff_count, .print = ftrace_traceoff_print, .init = ftrace_count_init, .free = ftrace_count_free, }; static struct ftrace_probe_ops stacktrace_count_probe_ops = { .func = ftrace_stacktrace_count, .print = ftrace_stacktrace_print, .init = ftrace_count_init, .free = ftrace_count_free, }; static struct ftrace_probe_ops dump_probe_ops = { .func = ftrace_dump_probe, .print = ftrace_dump_print, .init = ftrace_count_init, .free = ftrace_count_free, }; static struct ftrace_probe_ops cpudump_probe_ops = { .func = ftrace_cpudump_probe, .print = ftrace_cpudump_print, }; static struct ftrace_probe_ops traceon_probe_ops = { .func = ftrace_traceon, .print = ftrace_traceon_print, }; static struct ftrace_probe_ops traceoff_probe_ops = { .func = ftrace_traceoff, .print = ftrace_traceoff_print, }; static struct ftrace_probe_ops stacktrace_probe_ops = { .func = ftrace_stacktrace, .print = ftrace_stacktrace_print, }; static int ftrace_trace_probe_callback(struct trace_array *tr, struct ftrace_probe_ops *ops, struct ftrace_hash *hash, char *glob, char *cmd, char *param, int enable) { void *count = (void *)-1; char *number; int ret; /* hash funcs only work with set_ftrace_filter */ if (!enable) return -EINVAL; if (glob[0] == '!') return unregister_ftrace_function_probe_func(glob+1, tr, ops); if (!param) goto out_reg; number = strsep(¶m, ":"); if (!strlen(number)) goto out_reg; /* * We use the callback data field (which is a pointer) * as our counter. */ ret = kstrtoul(number, 0, (unsigned long *)&count); if (ret) return ret; out_reg: ret = register_ftrace_function_probe(glob, tr, ops, count); return ret < 0 ? ret : 0; } static int ftrace_trace_onoff_callback(struct trace_array *tr, struct ftrace_hash *hash, char *glob, char *cmd, char *param, int enable) { struct ftrace_probe_ops *ops; if (!tr) return -ENODEV; /* we register both traceon and traceoff to this callback */ if (strcmp(cmd, "traceon") == 0) ops = param ? &traceon_count_probe_ops : &traceon_probe_ops; else ops = param ? &traceoff_count_probe_ops : &traceoff_probe_ops; return ftrace_trace_probe_callback(tr, ops, hash, glob, cmd, param, enable); } static int ftrace_stacktrace_callback(struct trace_array *tr, struct ftrace_hash *hash, char *glob, char *cmd, char *param, int enable) { struct ftrace_probe_ops *ops; if (!tr) return -ENODEV; ops = param ? &stacktrace_count_probe_ops : &stacktrace_probe_ops; return ftrace_trace_probe_callback(tr, ops, hash, glob, cmd, param, enable); } static int ftrace_dump_callback(struct trace_array *tr, struct ftrace_hash *hash, char *glob, char *cmd, char *param, int enable) { struct ftrace_probe_ops *ops; if (!tr) return -ENODEV; ops = &dump_probe_ops; /* Only dump once. */ return ftrace_trace_probe_callback(tr, ops, hash, glob, cmd, "1", enable); } static int ftrace_cpudump_callback(struct trace_array *tr, struct ftrace_hash *hash, char *glob, char *cmd, char *param, int enable) { struct ftrace_probe_ops *ops; if (!tr) return -ENODEV; ops = &cpudump_probe_ops; /* Only dump once. */ return ftrace_trace_probe_callback(tr, ops, hash, glob, cmd, "1", enable); } static struct ftrace_func_command ftrace_traceon_cmd = { .name = "traceon", .func = ftrace_trace_onoff_callback, }; static struct ftrace_func_command ftrace_traceoff_cmd = { .name = "traceoff", .func = ftrace_trace_onoff_callback, }; static struct ftrace_func_command ftrace_stacktrace_cmd = { .name = "stacktrace", .func = ftrace_stacktrace_callback, }; static struct ftrace_func_command ftrace_dump_cmd = { .name = "dump", .func = ftrace_dump_callback, }; static struct ftrace_func_command ftrace_cpudump_cmd = { .name = "cpudump", .func = ftrace_cpudump_callback, }; static int __init init_func_cmd_traceon(void) { int ret; ret = register_ftrace_command(&ftrace_traceoff_cmd); if (ret) return ret; ret = register_ftrace_command(&ftrace_traceon_cmd); if (ret) goto out_free_traceoff; ret = register_ftrace_command(&ftrace_stacktrace_cmd); if (ret) goto out_free_traceon; ret = register_ftrace_command(&ftrace_dump_cmd); if (ret) goto out_free_stacktrace; ret = register_ftrace_command(&ftrace_cpudump_cmd); if (ret) goto out_free_dump; return 0; out_free_dump: unregister_ftrace_command(&ftrace_dump_cmd); out_free_stacktrace: unregister_ftrace_command(&ftrace_stacktrace_cmd); out_free_traceon: unregister_ftrace_command(&ftrace_traceon_cmd); out_free_traceoff: unregister_ftrace_command(&ftrace_traceoff_cmd); return ret; } #else static inline int init_func_cmd_traceon(void) { return 0; } #endif /* CONFIG_DYNAMIC_FTRACE */ __init int init_function_trace(void) { init_func_cmd_traceon(); return register_tracer(&function_trace); } |