1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Kprobes-based tracing events 4 * 5 * Created by Masami Hiramatsu <mhiramat@redhat.com> 6 * 7 */ 8 #define pr_fmt(fmt) "trace_kprobe: " fmt 9 10 #include <linux/bpf-cgroup.h> 11 #include <linux/cleanup.h> 12 #include <linux/security.h> 13 #include <linux/module.h> 14 #include <linux/uaccess.h> 15 #include <linux/rculist.h> 16 #include <linux/error-injection.h> 17 18 #include <asm/setup.h> /* for COMMAND_LINE_SIZE */ 19 20 #include "trace_dynevent.h" 21 #include "trace_kprobe_selftest.h" 22 #include "trace_probe.h" 23 #include "trace_probe_tmpl.h" 24 #include "trace_probe_kernel.h" 25 26 #define KPROBE_EVENT_SYSTEM "kprobes" 27 #define KRETPROBE_MAXACTIVE_MAX 4096 28 29 /* Kprobe early definition from command line */ 30 static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata; 31 32 static int __init set_kprobe_boot_events(char *str) 33 { 34 strscpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE); 35 disable_tracing_selftest("running kprobe events"); 36 37 return 1; 38 } 39 __setup("kprobe_event=", set_kprobe_boot_events); 40 41 static int trace_kprobe_create(const char *raw_command); 42 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev); 43 static int trace_kprobe_release(struct dyn_event *ev); 44 static bool trace_kprobe_is_busy(struct dyn_event *ev); 45 static bool trace_kprobe_match(const char *system, const char *event, 46 int argc, const char **argv, struct dyn_event *ev); 47 48 static struct dyn_event_operations trace_kprobe_ops = { 49 .create = trace_kprobe_create, 50 .show = trace_kprobe_show, 51 .is_busy = trace_kprobe_is_busy, 52 .free = trace_kprobe_release, 53 .match = trace_kprobe_match, 54 }; 55 56 /* 57 * Kprobe event core functions 58 */ 59 struct trace_kprobe { 60 struct dyn_event devent; 61 struct kretprobe rp; /* Use rp.kp for kprobe use */ 62 unsigned long __percpu *nhit; 63 const char *symbol; /* symbol name */ 64 struct trace_probe tp; 65 }; 66 67 static bool is_trace_kprobe(struct dyn_event *ev) 68 { 69 return ev->ops == &trace_kprobe_ops; 70 } 71 72 static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev) 73 { 74 return container_of(ev, struct trace_kprobe, devent); 75 } 76 77 /** 78 * for_each_trace_kprobe - iterate over the trace_kprobe list 79 * @pos: the struct trace_kprobe * for each entry 80 * @dpos: the struct dyn_event * to use as a loop cursor 81 */ 82 #define for_each_trace_kprobe(pos, dpos) \ 83 for_each_dyn_event(dpos) \ 84 if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos))) 85 86 static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk) 87 { 88 return tk->rp.handler != NULL; 89 } 90 91 static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk) 92 { 93 return tk->symbol ? tk->symbol : "unknown"; 94 } 95 96 static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk) 97 { 98 return tk->rp.kp.offset; 99 } 100 101 static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) 102 { 103 return kprobe_gone(&tk->rp.kp); 104 } 105 106 static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, 107 struct module *mod) 108 { 109 int len = strlen(module_name(mod)); 110 const char *name = trace_kprobe_symbol(tk); 111 112 return strncmp(module_name(mod), name, len) == 0 && name[len] == ':'; 113 } 114 115 #ifdef CONFIG_MODULES 116 static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) 117 { 118 char *p; 119 bool ret; 120 121 if (!tk->symbol) 122 return false; 123 p = strchr(tk->symbol, ':'); 124 if (!p) 125 return true; 126 *p = '\0'; 127 rcu_read_lock_sched(); 128 ret = !!find_module(tk->symbol); 129 rcu_read_unlock_sched(); 130 *p = ':'; 131 132 return ret; 133 } 134 #else 135 static inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) 136 { 137 return false; 138 } 139 #endif 140 141 static bool trace_kprobe_is_busy(struct dyn_event *ev) 142 { 143 struct trace_kprobe *tk = to_trace_kprobe(ev); 144 145 return trace_probe_is_enabled(&tk->tp); 146 } 147 148 static bool trace_kprobe_match_command_head(struct trace_kprobe *tk, 149 int argc, const char **argv) 150 { 151 char buf[MAX_ARGSTR_LEN + 1]; 152 153 if (!argc) 154 return true; 155 156 if (!tk->symbol) 157 snprintf(buf, sizeof(buf), "0x%p", tk->rp.kp.addr); 158 else if (tk->rp.kp.offset) 159 snprintf(buf, sizeof(buf), "%s+%u", 160 trace_kprobe_symbol(tk), tk->rp.kp.offset); 161 else 162 snprintf(buf, sizeof(buf), "%s", trace_kprobe_symbol(tk)); 163 if (strcmp(buf, argv[0])) 164 return false; 165 argc--; argv++; 166 167 return trace_probe_match_command_args(&tk->tp, argc, argv); 168 } 169 170 static bool trace_kprobe_match(const char *system, const char *event, 171 int argc, const char **argv, struct dyn_event *ev) 172 { 173 struct trace_kprobe *tk = to_trace_kprobe(ev); 174 175 return (event[0] == '\0' || 176 strcmp(trace_probe_name(&tk->tp), event) == 0) && 177 (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) && 178 trace_kprobe_match_command_head(tk, argc, argv); 179 } 180 181 static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk) 182 { 183 unsigned long nhit = 0; 184 int cpu; 185 186 for_each_possible_cpu(cpu) 187 nhit += *per_cpu_ptr(tk->nhit, cpu); 188 189 return nhit; 190 } 191 192 static nokprobe_inline bool trace_kprobe_is_registered(struct trace_kprobe *tk) 193 { 194 return !(list_empty(&tk->rp.kp.list) && 195 hlist_unhashed(&tk->rp.kp.hlist)); 196 } 197 198 /* Return 0 if it fails to find the symbol address */ 199 static nokprobe_inline 200 unsigned long trace_kprobe_address(struct trace_kprobe *tk) 201 { 202 unsigned long addr; 203 204 if (tk->symbol) { 205 addr = (unsigned long) 206 kallsyms_lookup_name(trace_kprobe_symbol(tk)); 207 if (addr) 208 addr += tk->rp.kp.offset; 209 } else { 210 addr = (unsigned long)tk->rp.kp.addr; 211 } 212 return addr; 213 } 214 215 static nokprobe_inline struct trace_kprobe * 216 trace_kprobe_primary_from_call(struct trace_event_call *call) 217 { 218 struct trace_probe *tp; 219 220 tp = trace_probe_primary_from_call(call); 221 if (WARN_ON_ONCE(!tp)) 222 return NULL; 223 224 return container_of(tp, struct trace_kprobe, tp); 225 } 226 227 bool trace_kprobe_on_func_entry(struct trace_event_call *call) 228 { 229 struct trace_kprobe *tk = trace_kprobe_primary_from_call(call); 230 231 return tk ? (kprobe_on_func_entry(tk->rp.kp.addr, 232 tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name, 233 tk->rp.kp.addr ? 0 : tk->rp.kp.offset) == 0) : false; 234 } 235 236 bool trace_kprobe_error_injectable(struct trace_event_call *call) 237 { 238 struct trace_kprobe *tk = trace_kprobe_primary_from_call(call); 239 240 return tk ? within_error_injection_list(trace_kprobe_address(tk)) : 241 false; 242 } 243 244 static int register_kprobe_event(struct trace_kprobe *tk); 245 static int unregister_kprobe_event(struct trace_kprobe *tk); 246 247 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); 248 static int kretprobe_dispatcher(struct kretprobe_instance *ri, 249 struct pt_regs *regs); 250 251 static void free_trace_kprobe(struct trace_kprobe *tk) 252 { 253 if (tk) { 254 trace_probe_cleanup(&tk->tp); 255 kfree(tk->symbol); 256 free_percpu(tk->nhit); 257 kfree(tk); 258 } 259 } 260 261 DEFINE_FREE(free_trace_kprobe, struct trace_kprobe *, 262 if (!IS_ERR_OR_NULL(_T)) free_trace_kprobe(_T)) 263 264 /* 265 * Allocate new trace_probe and initialize it (including kprobes). 266 */ 267 static struct trace_kprobe *alloc_trace_kprobe(const char *group, 268 const char *event, 269 void *addr, 270 const char *symbol, 271 unsigned long offs, 272 int maxactive, 273 int nargs, bool is_return) 274 { 275 struct trace_kprobe *tk __free(free_trace_kprobe) = NULL; 276 int ret = -ENOMEM; 277 278 tk = kzalloc(struct_size(tk, tp.args, nargs), GFP_KERNEL); 279 if (!tk) 280 return ERR_PTR(ret); 281 282 tk->nhit = alloc_percpu(unsigned long); 283 if (!tk->nhit) 284 return ERR_PTR(ret); 285 286 if (symbol) { 287 tk->symbol = kstrdup(symbol, GFP_KERNEL); 288 if (!tk->symbol) 289 return ERR_PTR(ret); 290 tk->rp.kp.symbol_name = tk->symbol; 291 tk->rp.kp.offset = offs; 292 } else 293 tk->rp.kp.addr = addr; 294 295 if (is_return) 296 tk->rp.handler = kretprobe_dispatcher; 297 else 298 tk->rp.kp.pre_handler = kprobe_dispatcher; 299 300 tk->rp.maxactive = maxactive; 301 INIT_HLIST_NODE(&tk->rp.kp.hlist); 302 INIT_LIST_HEAD(&tk->rp.kp.list); 303 304 ret = trace_probe_init(&tk->tp, event, group, false, nargs); 305 if (ret < 0) 306 return ERR_PTR(ret); 307 308 dyn_event_init(&tk->devent, &trace_kprobe_ops); 309 return_ptr(tk); 310 } 311 312 static struct trace_kprobe *find_trace_kprobe(const char *event, 313 const char *group) 314 { 315 struct dyn_event *pos; 316 struct trace_kprobe *tk; 317 318 for_each_trace_kprobe(tk, pos) 319 if (strcmp(trace_probe_name(&tk->tp), event) == 0 && 320 strcmp(trace_probe_group_name(&tk->tp), group) == 0) 321 return tk; 322 return NULL; 323 } 324 325 static inline int __enable_trace_kprobe(struct trace_kprobe *tk) 326 { 327 int ret = 0; 328 329 if (trace_kprobe_is_registered(tk) && !trace_kprobe_has_gone(tk)) { 330 if (trace_kprobe_is_return(tk)) 331 ret = enable_kretprobe(&tk->rp); 332 else 333 ret = enable_kprobe(&tk->rp.kp); 334 } 335 336 return ret; 337 } 338 339 static void __disable_trace_kprobe(struct trace_probe *tp) 340 { 341 struct trace_kprobe *tk; 342 343 list_for_each_entry(tk, trace_probe_probe_list(tp), tp.list) { 344 if (!trace_kprobe_is_registered(tk)) 345 continue; 346 if (trace_kprobe_is_return(tk)) 347 disable_kretprobe(&tk->rp); 348 else 349 disable_kprobe(&tk->rp.kp); 350 } 351 } 352 353 /* 354 * Enable trace_probe 355 * if the file is NULL, enable "perf" handler, or enable "trace" handler. 356 */ 357 static int enable_trace_kprobe(struct trace_event_call *call, 358 struct trace_event_file *file) 359 { 360 struct trace_probe *tp; 361 struct trace_kprobe *tk; 362 bool enabled; 363 int ret = 0; 364 365 tp = trace_probe_primary_from_call(call); 366 if (WARN_ON_ONCE(!tp)) 367 return -ENODEV; 368 enabled = trace_probe_is_enabled(tp); 369 370 /* This also changes "enabled" state */ 371 if (file) { 372 ret = trace_probe_add_file(tp, file); 373 if (ret) 374 return ret; 375 } else 376 trace_probe_set_flag(tp, TP_FLAG_PROFILE); 377 378 if (enabled) 379 return 0; 380 381 list_for_each_entry(tk, trace_probe_probe_list(tp), tp.list) { 382 if (trace_kprobe_has_gone(tk)) 383 continue; 384 ret = __enable_trace_kprobe(tk); 385 if (ret) 386 break; 387 enabled = true; 388 } 389 390 if (ret) { 391 /* Failed to enable one of them. Roll back all */ 392 if (enabled) 393 __disable_trace_kprobe(tp); 394 if (file) 395 trace_probe_remove_file(tp, file); 396 else 397 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 398 } 399 400 return ret; 401 } 402 403 /* 404 * Disable trace_probe 405 * if the file is NULL, disable "perf" handler, or disable "trace" handler. 406 */ 407 static int disable_trace_kprobe(struct trace_event_call *call, 408 struct trace_event_file *file) 409 { 410 struct trace_probe *tp; 411 412 tp = trace_probe_primary_from_call(call); 413 if (WARN_ON_ONCE(!tp)) 414 return -ENODEV; 415 416 if (file) { 417 if (!trace_probe_get_file_link(tp, file)) 418 return -ENOENT; 419 if (!trace_probe_has_single_file(tp)) 420 goto out; 421 trace_probe_clear_flag(tp, TP_FLAG_TRACE); 422 } else 423 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 424 425 if (!trace_probe_is_enabled(tp)) 426 __disable_trace_kprobe(tp); 427 428 out: 429 if (file) 430 /* 431 * Synchronization is done in below function. For perf event, 432 * file == NULL and perf_trace_event_unreg() calls 433 * tracepoint_synchronize_unregister() to ensure synchronize 434 * event. We don't need to care about it. 435 */ 436 trace_probe_remove_file(tp, file); 437 438 return 0; 439 } 440 441 #if defined(CONFIG_DYNAMIC_FTRACE) && \ 442 !defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE) 443 static bool __within_notrace_func(unsigned long addr) 444 { 445 unsigned long offset, size; 446 447 if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset)) 448 return false; 449 450 /* Get the entry address of the target function */ 451 addr -= offset; 452 453 /* 454 * Since ftrace_location_range() does inclusive range check, we need 455 * to subtract 1 byte from the end address. 456 */ 457 return !ftrace_location_range(addr, addr + size - 1); 458 } 459 460 static bool within_notrace_func(struct trace_kprobe *tk) 461 { 462 unsigned long addr = trace_kprobe_address(tk); 463 char symname[KSYM_NAME_LEN], *p; 464 465 if (!__within_notrace_func(addr)) 466 return false; 467 468 /* Check if the address is on a suffixed-symbol */ 469 if (!lookup_symbol_name(addr, symname)) { 470 p = strchr(symname, '.'); 471 if (!p) 472 return true; 473 *p = '\0'; 474 addr = (unsigned long)kprobe_lookup_name(symname, 0); 475 if (addr) 476 return __within_notrace_func(addr); 477 } 478 479 return true; 480 } 481 #else 482 #define within_notrace_func(tk) (false) 483 #endif 484 485 /* Internal register function - just handle k*probes and flags */ 486 static int __register_trace_kprobe(struct trace_kprobe *tk) 487 { 488 int i, ret; 489 490 ret = security_locked_down(LOCKDOWN_KPROBES); 491 if (ret) 492 return ret; 493 494 if (trace_kprobe_is_registered(tk)) 495 return -EINVAL; 496 497 if (within_notrace_func(tk)) { 498 pr_warn("Could not probe notrace function %ps\n", 499 (void *)trace_kprobe_address(tk)); 500 return -EINVAL; 501 } 502 503 for (i = 0; i < tk->tp.nr_args; i++) { 504 ret = traceprobe_update_arg(&tk->tp.args[i]); 505 if (ret) 506 return ret; 507 } 508 509 /* Set/clear disabled flag according to tp->flag */ 510 if (trace_probe_is_enabled(&tk->tp)) 511 tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; 512 else 513 tk->rp.kp.flags |= KPROBE_FLAG_DISABLED; 514 515 if (trace_kprobe_is_return(tk)) 516 ret = register_kretprobe(&tk->rp); 517 else 518 ret = register_kprobe(&tk->rp.kp); 519 520 return ret; 521 } 522 523 /* Internal unregister function - just handle k*probes and flags */ 524 static void __unregister_trace_kprobe(struct trace_kprobe *tk) 525 { 526 if (trace_kprobe_is_registered(tk)) { 527 if (trace_kprobe_is_return(tk)) 528 unregister_kretprobe(&tk->rp); 529 else 530 unregister_kprobe(&tk->rp.kp); 531 /* Cleanup kprobe for reuse and mark it unregistered */ 532 INIT_HLIST_NODE(&tk->rp.kp.hlist); 533 INIT_LIST_HEAD(&tk->rp.kp.list); 534 if (tk->rp.kp.symbol_name) 535 tk->rp.kp.addr = NULL; 536 } 537 } 538 539 /* Unregister a trace_probe and probe_event */ 540 static int unregister_trace_kprobe(struct trace_kprobe *tk) 541 { 542 /* If other probes are on the event, just unregister kprobe */ 543 if (trace_probe_has_sibling(&tk->tp)) 544 goto unreg; 545 546 /* Enabled event can not be unregistered */ 547 if (trace_probe_is_enabled(&tk->tp)) 548 return -EBUSY; 549 550 /* If there's a reference to the dynamic event */ 551 if (trace_event_dyn_busy(trace_probe_event_call(&tk->tp))) 552 return -EBUSY; 553 554 /* Will fail if probe is being used by ftrace or perf */ 555 if (unregister_kprobe_event(tk)) 556 return -EBUSY; 557 558 unreg: 559 __unregister_trace_kprobe(tk); 560 dyn_event_remove(&tk->devent); 561 trace_probe_unlink(&tk->tp); 562 563 return 0; 564 } 565 566 static bool trace_kprobe_has_same_kprobe(struct trace_kprobe *orig, 567 struct trace_kprobe *comp) 568 { 569 struct trace_probe_event *tpe = orig->tp.event; 570 int i; 571 572 list_for_each_entry(orig, &tpe->probes, tp.list) { 573 if (strcmp(trace_kprobe_symbol(orig), 574 trace_kprobe_symbol(comp)) || 575 trace_kprobe_offset(orig) != trace_kprobe_offset(comp)) 576 continue; 577 578 /* 579 * trace_probe_compare_arg_type() ensured that nr_args and 580 * each argument name and type are same. Let's compare comm. 581 */ 582 for (i = 0; i < orig->tp.nr_args; i++) { 583 if (strcmp(orig->tp.args[i].comm, 584 comp->tp.args[i].comm)) 585 break; 586 } 587 588 if (i == orig->tp.nr_args) 589 return true; 590 } 591 592 return false; 593 } 594 595 static int append_trace_kprobe(struct trace_kprobe *tk, struct trace_kprobe *to) 596 { 597 int ret; 598 599 ret = trace_probe_compare_arg_type(&tk->tp, &to->tp); 600 if (ret) { 601 /* Note that argument starts index = 2 */ 602 trace_probe_log_set_index(ret + 1); 603 trace_probe_log_err(0, DIFF_ARG_TYPE); 604 return -EEXIST; 605 } 606 if (trace_kprobe_has_same_kprobe(to, tk)) { 607 trace_probe_log_set_index(0); 608 trace_probe_log_err(0, SAME_PROBE); 609 return -EEXIST; 610 } 611 612 /* Append to existing event */ 613 ret = trace_probe_append(&tk->tp, &to->tp); 614 if (ret) 615 return ret; 616 617 /* Register k*probe */ 618 ret = __register_trace_kprobe(tk); 619 if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) { 620 pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); 621 ret = 0; 622 } 623 624 if (ret) 625 trace_probe_unlink(&tk->tp); 626 else 627 dyn_event_add(&tk->devent, trace_probe_event_call(&tk->tp)); 628 629 return ret; 630 } 631 632 /* Register a trace_probe and probe_event */ 633 static int register_trace_kprobe(struct trace_kprobe *tk) 634 { 635 struct trace_kprobe *old_tk; 636 int ret; 637 638 guard(mutex)(&event_mutex); 639 640 old_tk = find_trace_kprobe(trace_probe_name(&tk->tp), 641 trace_probe_group_name(&tk->tp)); 642 if (old_tk) { 643 if (trace_kprobe_is_return(tk) != trace_kprobe_is_return(old_tk)) { 644 trace_probe_log_set_index(0); 645 trace_probe_log_err(0, DIFF_PROBE_TYPE); 646 return -EEXIST; 647 } 648 return append_trace_kprobe(tk, old_tk); 649 } 650 651 /* Register new event */ 652 ret = register_kprobe_event(tk); 653 if (ret) { 654 if (ret == -EEXIST) { 655 trace_probe_log_set_index(0); 656 trace_probe_log_err(0, EVENT_EXIST); 657 } else 658 pr_warn("Failed to register probe event(%d)\n", ret); 659 return ret; 660 } 661 662 /* Register k*probe */ 663 ret = __register_trace_kprobe(tk); 664 if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) { 665 pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); 666 ret = 0; 667 } 668 669 if (ret < 0) 670 unregister_kprobe_event(tk); 671 else 672 dyn_event_add(&tk->devent, trace_probe_event_call(&tk->tp)); 673 674 return ret; 675 } 676 677 #ifdef CONFIG_MODULES 678 static int validate_module_probe_symbol(const char *modname, const char *symbol); 679 680 static int register_module_trace_kprobe(struct module *mod, struct trace_kprobe *tk) 681 { 682 const char *p; 683 int ret = 0; 684 685 p = strchr(trace_kprobe_symbol(tk), ':'); 686 if (p) 687 ret = validate_module_probe_symbol(module_name(mod), p + 1); 688 if (!ret) 689 ret = __register_trace_kprobe(tk); 690 return ret; 691 } 692 693 /* Module notifier call back, checking event on the module */ 694 static int trace_kprobe_module_callback(struct notifier_block *nb, 695 unsigned long val, void *data) 696 { 697 struct module *mod = data; 698 struct dyn_event *pos; 699 struct trace_kprobe *tk; 700 int ret; 701 702 if (val != MODULE_STATE_COMING) 703 return NOTIFY_DONE; 704 705 /* Update probes on coming module */ 706 guard(mutex)(&event_mutex); 707 for_each_trace_kprobe(tk, pos) { 708 if (trace_kprobe_within_module(tk, mod)) { 709 /* Don't need to check busy - this should have gone. */ 710 __unregister_trace_kprobe(tk); 711 ret = register_module_trace_kprobe(mod, tk); 712 if (ret) 713 pr_warn("Failed to re-register probe %s on %s: %d\n", 714 trace_probe_name(&tk->tp), 715 module_name(mod), ret); 716 } 717 } 718 719 return NOTIFY_DONE; 720 } 721 722 static struct notifier_block trace_kprobe_module_nb = { 723 .notifier_call = trace_kprobe_module_callback, 724 .priority = 2 /* Invoked after kprobe and jump_label module callback */ 725 }; 726 static int trace_kprobe_register_module_notifier(void) 727 { 728 return register_module_notifier(&trace_kprobe_module_nb); 729 } 730 #else 731 static int trace_kprobe_register_module_notifier(void) 732 { 733 return 0; 734 } 735 #endif /* CONFIG_MODULES */ 736 737 static int count_symbols(void *data, unsigned long unused) 738 { 739 unsigned int *count = data; 740 741 (*count)++; 742 743 return 0; 744 } 745 746 struct sym_count_ctx { 747 unsigned int count; 748 const char *name; 749 }; 750 751 static int count_mod_symbols(void *data, const char *name, unsigned long unused) 752 { 753 struct sym_count_ctx *ctx = data; 754 755 if (strcmp(name, ctx->name) == 0) 756 ctx->count++; 757 758 return 0; 759 } 760 761 static unsigned int number_of_same_symbols(const char *mod, const char *func_name) 762 { 763 struct sym_count_ctx ctx = { .count = 0, .name = func_name }; 764 765 if (!mod) 766 kallsyms_on_each_match_symbol(count_symbols, func_name, &ctx.count); 767 768 module_kallsyms_on_each_symbol(mod, count_mod_symbols, &ctx); 769 770 return ctx.count; 771 } 772 773 static int validate_module_probe_symbol(const char *modname, const char *symbol) 774 { 775 unsigned int count = number_of_same_symbols(modname, symbol); 776 777 if (count > 1) { 778 /* 779 * Users should use ADDR to remove the ambiguity of 780 * using KSYM only. 781 */ 782 return -EADDRNOTAVAIL; 783 } else if (count == 0) { 784 /* 785 * We can return ENOENT earlier than when register the 786 * kprobe. 787 */ 788 return -ENOENT; 789 } 790 return 0; 791 } 792 793 #ifdef CONFIG_MODULES 794 /* Return NULL if the module is not loaded or under unloading. */ 795 static struct module *try_module_get_by_name(const char *name) 796 { 797 struct module *mod; 798 799 rcu_read_lock_sched(); 800 mod = find_module(name); 801 if (mod && !try_module_get(mod)) 802 mod = NULL; 803 rcu_read_unlock_sched(); 804 805 return mod; 806 } 807 #else 808 #define try_module_get_by_name(name) (NULL) 809 #endif 810 811 static int validate_probe_symbol(char *symbol) 812 { 813 struct module *mod = NULL; 814 char *modname = NULL, *p; 815 int ret = 0; 816 817 p = strchr(symbol, ':'); 818 if (p) { 819 modname = symbol; 820 symbol = p + 1; 821 *p = '\0'; 822 mod = try_module_get_by_name(modname); 823 if (!mod) 824 goto out; 825 } 826 827 ret = validate_module_probe_symbol(modname, symbol); 828 out: 829 if (p) 830 *p = ':'; 831 if (mod) 832 module_put(mod); 833 return ret; 834 } 835 836 static int trace_kprobe_entry_handler(struct kretprobe_instance *ri, 837 struct pt_regs *regs); 838 839 static int trace_kprobe_create_internal(int argc, const char *argv[], 840 struct traceprobe_parse_context *ctx) 841 { 842 /* 843 * Argument syntax: 844 * - Add kprobe: 845 * p[:[GRP/][EVENT]] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] 846 * - Add kretprobe: 847 * r[MAXACTIVE][:[GRP/][EVENT]] [MOD:]KSYM[+0] [FETCHARGS] 848 * Or 849 * p[:[GRP/][EVENT]] [MOD:]KSYM[+0]%return [FETCHARGS] 850 * 851 * Fetch args: 852 * $retval : fetch return value 853 * $stack : fetch stack address 854 * $stackN : fetch Nth of stack (N:0-) 855 * $comm : fetch current task comm 856 * @ADDR : fetch memory at ADDR (ADDR should be in kernel) 857 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) 858 * %REG : fetch register REG 859 * Dereferencing memory fetch: 860 * +|-offs(ARG) : fetch memory at ARG +|- offs address. 861 * Alias name of args: 862 * NAME=FETCHARG : set NAME as alias of FETCHARG. 863 * Type of args: 864 * FETCHARG:TYPE : use TYPE instead of unsigned long. 865 */ 866 struct trace_kprobe *tk __free(free_trace_kprobe) = NULL; 867 int i, len, new_argc = 0, ret = 0; 868 bool is_return = false; 869 char *symbol __free(kfree) = NULL; 870 char *tmp = NULL; 871 const char **new_argv __free(kfree) = NULL; 872 const char *event = NULL, *group = KPROBE_EVENT_SYSTEM; 873 enum probe_print_type ptype; 874 int maxactive = 0; 875 long offset = 0; 876 void *addr = NULL; 877 char buf[MAX_EVENT_NAME_LEN]; 878 char gbuf[MAX_EVENT_NAME_LEN]; 879 char abuf[MAX_BTF_ARGS_LEN]; 880 char *dbuf __free(kfree) = NULL; 881 882 switch (argv[0][0]) { 883 case 'r': 884 is_return = true; 885 break; 886 case 'p': 887 break; 888 default: 889 return -ECANCELED; 890 } 891 if (argc < 2) 892 return -ECANCELED; 893 894 event = strchr(&argv[0][1], ':'); 895 if (event) 896 event++; 897 898 if (isdigit(argv[0][1])) { 899 if (!is_return) { 900 trace_probe_log_err(1, BAD_MAXACT_TYPE); 901 return -EINVAL; 902 } 903 if (event) 904 len = event - &argv[0][1] - 1; 905 else 906 len = strlen(&argv[0][1]); 907 if (len > MAX_EVENT_NAME_LEN - 1) { 908 trace_probe_log_err(1, BAD_MAXACT); 909 return -EINVAL; 910 } 911 memcpy(buf, &argv[0][1], len); 912 buf[len] = '\0'; 913 ret = kstrtouint(buf, 0, &maxactive); 914 if (ret || !maxactive) { 915 trace_probe_log_err(1, BAD_MAXACT); 916 return -EINVAL; 917 } 918 /* kretprobes instances are iterated over via a list. The 919 * maximum should stay reasonable. 920 */ 921 if (maxactive > KRETPROBE_MAXACTIVE_MAX) { 922 trace_probe_log_err(1, MAXACT_TOO_BIG); 923 return -EINVAL; 924 } 925 } 926 927 /* try to parse an address. if that fails, try to read the 928 * input as a symbol. */ 929 if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) { 930 trace_probe_log_set_index(1); 931 /* Check whether uprobe event specified */ 932 if (strchr(argv[1], '/') && strchr(argv[1], ':')) 933 return -ECANCELED; 934 935 /* a symbol specified */ 936 symbol = kstrdup(argv[1], GFP_KERNEL); 937 if (!symbol) 938 return -ENOMEM; 939 940 tmp = strchr(symbol, '%'); 941 if (tmp) { 942 if (!strcmp(tmp, "%return")) { 943 *tmp = '\0'; 944 is_return = true; 945 } else { 946 trace_probe_log_err(tmp - symbol, BAD_ADDR_SUFFIX); 947 return -EINVAL; 948 } 949 } 950 951 /* TODO: support .init module functions */ 952 ret = traceprobe_split_symbol_offset(symbol, &offset); 953 if (ret || offset < 0 || offset > UINT_MAX) { 954 trace_probe_log_err(0, BAD_PROBE_ADDR); 955 return -EINVAL; 956 } 957 ret = validate_probe_symbol(symbol); 958 if (ret) { 959 if (ret == -EADDRNOTAVAIL) 960 trace_probe_log_err(0, NON_UNIQ_SYMBOL); 961 else 962 trace_probe_log_err(0, BAD_PROBE_ADDR); 963 return -EINVAL; 964 } 965 if (is_return) 966 ctx->flags |= TPARG_FL_RETURN; 967 ret = kprobe_on_func_entry(NULL, symbol, offset); 968 if (ret == 0 && !is_return) 969 ctx->flags |= TPARG_FL_FENTRY; 970 /* Defer the ENOENT case until register kprobe */ 971 if (ret == -EINVAL && is_return) { 972 trace_probe_log_err(0, BAD_RETPROBE); 973 return -EINVAL; 974 } 975 } 976 977 trace_probe_log_set_index(0); 978 if (event) { 979 ret = traceprobe_parse_event_name(&event, &group, gbuf, 980 event - argv[0]); 981 if (ret) 982 return ret; 983 } 984 985 if (!event) { 986 /* Make a new event name */ 987 if (symbol) 988 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", 989 is_return ? 'r' : 'p', symbol, offset); 990 else 991 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", 992 is_return ? 'r' : 'p', addr); 993 sanitize_event_name(buf); 994 event = buf; 995 } 996 997 argc -= 2; argv += 2; 998 ctx->funcname = symbol; 999 new_argv = traceprobe_expand_meta_args(argc, argv, &new_argc, 1000 abuf, MAX_BTF_ARGS_LEN, ctx); 1001 if (IS_ERR(new_argv)) { 1002 ret = PTR_ERR(new_argv); 1003 new_argv = NULL; 1004 return ret; 1005 } 1006 if (new_argv) { 1007 argc = new_argc; 1008 argv = new_argv; 1009 } 1010 if (argc > MAX_TRACE_ARGS) { 1011 trace_probe_log_set_index(2); 1012 trace_probe_log_err(0, TOO_MANY_ARGS); 1013 return -E2BIG; 1014 } 1015 1016 ret = traceprobe_expand_dentry_args(argc, argv, &dbuf); 1017 if (ret) 1018 return ret; 1019 1020 /* setup a probe */ 1021 tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive, 1022 argc, is_return); 1023 if (IS_ERR(tk)) { 1024 ret = PTR_ERR(tk); 1025 /* This must return -ENOMEM, else there is a bug */ 1026 WARN_ON_ONCE(ret != -ENOMEM); 1027 return ret; /* We know tk is not allocated */ 1028 } 1029 1030 /* parse arguments */ 1031 for (i = 0; i < argc; i++) { 1032 trace_probe_log_set_index(i + 2); 1033 ctx->offset = 0; 1034 ret = traceprobe_parse_probe_arg(&tk->tp, i, argv[i], ctx); 1035 if (ret) 1036 return ret; /* This can be -ENOMEM */ 1037 } 1038 /* entry handler for kretprobe */ 1039 if (is_return && tk->tp.entry_arg) { 1040 tk->rp.entry_handler = trace_kprobe_entry_handler; 1041 tk->rp.data_size = traceprobe_get_entry_data_size(&tk->tp); 1042 } 1043 1044 ptype = is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; 1045 ret = traceprobe_set_print_fmt(&tk->tp, ptype); 1046 if (ret < 0) 1047 return ret; 1048 1049 ret = register_trace_kprobe(tk); 1050 if (ret) { 1051 trace_probe_log_set_index(1); 1052 if (ret == -EILSEQ) 1053 trace_probe_log_err(0, BAD_INSN_BNDRY); 1054 else if (ret == -ENOENT) 1055 trace_probe_log_err(0, BAD_PROBE_ADDR); 1056 else if (ret != -ENOMEM && ret != -EEXIST) 1057 trace_probe_log_err(0, FAIL_REG_PROBE); 1058 return ret; 1059 } 1060 /* 1061 * Here, 'tk' has been registered to the list successfully, 1062 * so we don't need to free it. 1063 */ 1064 tk = NULL; 1065 1066 return 0; 1067 } 1068 1069 static int trace_kprobe_create_cb(int argc, const char *argv[]) 1070 { 1071 struct traceprobe_parse_context ctx = { .flags = TPARG_FL_KERNEL }; 1072 int ret; 1073 1074 trace_probe_log_init("trace_kprobe", argc, argv); 1075 1076 ret = trace_kprobe_create_internal(argc, argv, &ctx); 1077 1078 traceprobe_finish_parse(&ctx); 1079 trace_probe_log_clear(); 1080 return ret; 1081 } 1082 1083 static int trace_kprobe_create(const char *raw_command) 1084 { 1085 return trace_probe_create(raw_command, trace_kprobe_create_cb); 1086 } 1087 1088 static int create_or_delete_trace_kprobe(const char *raw_command) 1089 { 1090 int ret; 1091 1092 if (raw_command[0] == '-') 1093 return dyn_event_release(raw_command, &trace_kprobe_ops); 1094 1095 ret = trace_kprobe_create(raw_command); 1096 return ret == -ECANCELED ? -EINVAL : ret; 1097 } 1098 1099 static int trace_kprobe_run_command(struct dynevent_cmd *cmd) 1100 { 1101 return create_or_delete_trace_kprobe(cmd->seq.buffer); 1102 } 1103 1104 /** 1105 * kprobe_event_cmd_init - Initialize a kprobe event command object 1106 * @cmd: A pointer to the dynevent_cmd struct representing the new event 1107 * @buf: A pointer to the buffer used to build the command 1108 * @maxlen: The length of the buffer passed in @buf 1109 * 1110 * Initialize a synthetic event command object. Use this before 1111 * calling any of the other kprobe_event functions. 1112 */ 1113 void kprobe_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen) 1114 { 1115 dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_KPROBE, 1116 trace_kprobe_run_command); 1117 } 1118 EXPORT_SYMBOL_GPL(kprobe_event_cmd_init); 1119 1120 /** 1121 * __kprobe_event_gen_cmd_start - Generate a kprobe event command from arg list 1122 * @cmd: A pointer to the dynevent_cmd struct representing the new event 1123 * @kretprobe: Is this a return probe? 1124 * @name: The name of the kprobe event 1125 * @loc: The location of the kprobe event 1126 * @...: Variable number of arg (pairs), one pair for each field 1127 * 1128 * NOTE: Users normally won't want to call this function directly, but 1129 * rather use the kprobe_event_gen_cmd_start() wrapper, which automatically 1130 * adds a NULL to the end of the arg list. If this function is used 1131 * directly, make sure the last arg in the variable arg list is NULL. 1132 * 1133 * Generate a kprobe event command to be executed by 1134 * kprobe_event_gen_cmd_end(). This function can be used to generate the 1135 * complete command or only the first part of it; in the latter case, 1136 * kprobe_event_add_fields() can be used to add more fields following this. 1137 * 1138 * Unlikely the synth_event_gen_cmd_start(), @loc must be specified. This 1139 * returns -EINVAL if @loc == NULL. 1140 * 1141 * Return: 0 if successful, error otherwise. 1142 */ 1143 int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe, 1144 const char *name, const char *loc, ...) 1145 { 1146 char buf[MAX_EVENT_NAME_LEN]; 1147 struct dynevent_arg arg; 1148 va_list args; 1149 int ret; 1150 1151 if (cmd->type != DYNEVENT_TYPE_KPROBE) 1152 return -EINVAL; 1153 1154 if (!loc) 1155 return -EINVAL; 1156 1157 if (kretprobe) 1158 snprintf(buf, MAX_EVENT_NAME_LEN, "r:kprobes/%s", name); 1159 else 1160 snprintf(buf, MAX_EVENT_NAME_LEN, "p:kprobes/%s", name); 1161 1162 ret = dynevent_str_add(cmd, buf); 1163 if (ret) 1164 return ret; 1165 1166 dynevent_arg_init(&arg, 0); 1167 arg.str = loc; 1168 ret = dynevent_arg_add(cmd, &arg, NULL); 1169 if (ret) 1170 return ret; 1171 1172 va_start(args, loc); 1173 for (;;) { 1174 const char *field; 1175 1176 field = va_arg(args, const char *); 1177 if (!field) 1178 break; 1179 1180 if (++cmd->n_fields > MAX_TRACE_ARGS) { 1181 ret = -EINVAL; 1182 break; 1183 } 1184 1185 arg.str = field; 1186 ret = dynevent_arg_add(cmd, &arg, NULL); 1187 if (ret) 1188 break; 1189 } 1190 va_end(args); 1191 1192 return ret; 1193 } 1194 EXPORT_SYMBOL_GPL(__kprobe_event_gen_cmd_start); 1195 1196 /** 1197 * __kprobe_event_add_fields - Add probe fields to a kprobe command from arg list 1198 * @cmd: A pointer to the dynevent_cmd struct representing the new event 1199 * @...: Variable number of arg (pairs), one pair for each field 1200 * 1201 * NOTE: Users normally won't want to call this function directly, but 1202 * rather use the kprobe_event_add_fields() wrapper, which 1203 * automatically adds a NULL to the end of the arg list. If this 1204 * function is used directly, make sure the last arg in the variable 1205 * arg list is NULL. 1206 * 1207 * Add probe fields to an existing kprobe command using a variable 1208 * list of args. Fields are added in the same order they're listed. 1209 * 1210 * Return: 0 if successful, error otherwise. 1211 */ 1212 int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...) 1213 { 1214 struct dynevent_arg arg; 1215 va_list args; 1216 int ret = 0; 1217 1218 if (cmd->type != DYNEVENT_TYPE_KPROBE) 1219 return -EINVAL; 1220 1221 dynevent_arg_init(&arg, 0); 1222 1223 va_start(args, cmd); 1224 for (;;) { 1225 const char *field; 1226 1227 field = va_arg(args, const char *); 1228 if (!field) 1229 break; 1230 1231 if (++cmd->n_fields > MAX_TRACE_ARGS) { 1232 ret = -EINVAL; 1233 break; 1234 } 1235 1236 arg.str = field; 1237 ret = dynevent_arg_add(cmd, &arg, NULL); 1238 if (ret) 1239 break; 1240 } 1241 va_end(args); 1242 1243 return ret; 1244 } 1245 EXPORT_SYMBOL_GPL(__kprobe_event_add_fields); 1246 1247 /** 1248 * kprobe_event_delete - Delete a kprobe event 1249 * @name: The name of the kprobe event to delete 1250 * 1251 * Delete a kprobe event with the give @name from kernel code rather 1252 * than directly from the command line. 1253 * 1254 * Return: 0 if successful, error otherwise. 1255 */ 1256 int kprobe_event_delete(const char *name) 1257 { 1258 char buf[MAX_EVENT_NAME_LEN]; 1259 1260 snprintf(buf, MAX_EVENT_NAME_LEN, "-:%s", name); 1261 1262 return create_or_delete_trace_kprobe(buf); 1263 } 1264 EXPORT_SYMBOL_GPL(kprobe_event_delete); 1265 1266 static int trace_kprobe_release(struct dyn_event *ev) 1267 { 1268 struct trace_kprobe *tk = to_trace_kprobe(ev); 1269 int ret = unregister_trace_kprobe(tk); 1270 1271 if (!ret) 1272 free_trace_kprobe(tk); 1273 return ret; 1274 } 1275 1276 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev) 1277 { 1278 struct trace_kprobe *tk = to_trace_kprobe(ev); 1279 int i; 1280 1281 seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p'); 1282 if (trace_kprobe_is_return(tk) && tk->rp.maxactive) 1283 seq_printf(m, "%d", tk->rp.maxactive); 1284 seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp), 1285 trace_probe_name(&tk->tp)); 1286 1287 if (!tk->symbol) 1288 seq_printf(m, " 0x%p", tk->rp.kp.addr); 1289 else if (tk->rp.kp.offset) 1290 seq_printf(m, " %s+%u", trace_kprobe_symbol(tk), 1291 tk->rp.kp.offset); 1292 else 1293 seq_printf(m, " %s", trace_kprobe_symbol(tk)); 1294 1295 for (i = 0; i < tk->tp.nr_args; i++) 1296 seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm); 1297 seq_putc(m, '\n'); 1298 1299 return 0; 1300 } 1301 1302 static int probes_seq_show(struct seq_file *m, void *v) 1303 { 1304 struct dyn_event *ev = v; 1305 1306 if (!is_trace_kprobe(ev)) 1307 return 0; 1308 1309 return trace_kprobe_show(m, ev); 1310 } 1311 1312 static const struct seq_operations probes_seq_op = { 1313 .start = dyn_event_seq_start, 1314 .next = dyn_event_seq_next, 1315 .stop = dyn_event_seq_stop, 1316 .show = probes_seq_show 1317 }; 1318 1319 static int probes_open(struct inode *inode, struct file *file) 1320 { 1321 int ret; 1322 1323 ret = security_locked_down(LOCKDOWN_TRACEFS); 1324 if (ret) 1325 return ret; 1326 1327 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { 1328 ret = dyn_events_release_all(&trace_kprobe_ops); 1329 if (ret < 0) 1330 return ret; 1331 } 1332 1333 return seq_open(file, &probes_seq_op); 1334 } 1335 1336 static ssize_t probes_write(struct file *file, const char __user *buffer, 1337 size_t count, loff_t *ppos) 1338 { 1339 return trace_parse_run_command(file, buffer, count, ppos, 1340 create_or_delete_trace_kprobe); 1341 } 1342 1343 static const struct file_operations kprobe_events_ops = { 1344 .owner = THIS_MODULE, 1345 .open = probes_open, 1346 .read = seq_read, 1347 .llseek = seq_lseek, 1348 .release = seq_release, 1349 .write = probes_write, 1350 }; 1351 1352 static unsigned long trace_kprobe_missed(struct trace_kprobe *tk) 1353 { 1354 return trace_kprobe_is_return(tk) ? 1355 tk->rp.kp.nmissed + tk->rp.nmissed : tk->rp.kp.nmissed; 1356 } 1357 1358 /* Probes profiling interfaces */ 1359 static int probes_profile_seq_show(struct seq_file *m, void *v) 1360 { 1361 struct dyn_event *ev = v; 1362 struct trace_kprobe *tk; 1363 unsigned long nmissed; 1364 1365 if (!is_trace_kprobe(ev)) 1366 return 0; 1367 1368 tk = to_trace_kprobe(ev); 1369 nmissed = trace_kprobe_missed(tk); 1370 seq_printf(m, " %-44s %15lu %15lu\n", 1371 trace_probe_name(&tk->tp), 1372 trace_kprobe_nhit(tk), 1373 nmissed); 1374 1375 return 0; 1376 } 1377 1378 static const struct seq_operations profile_seq_op = { 1379 .start = dyn_event_seq_start, 1380 .next = dyn_event_seq_next, 1381 .stop = dyn_event_seq_stop, 1382 .show = probes_profile_seq_show 1383 }; 1384 1385 static int profile_open(struct inode *inode, struct file *file) 1386 { 1387 int ret; 1388 1389 ret = security_locked_down(LOCKDOWN_TRACEFS); 1390 if (ret) 1391 return ret; 1392 1393 return seq_open(file, &profile_seq_op); 1394 } 1395 1396 static const struct file_operations kprobe_profile_ops = { 1397 .owner = THIS_MODULE, 1398 .open = profile_open, 1399 .read = seq_read, 1400 .llseek = seq_lseek, 1401 .release = seq_release, 1402 }; 1403 1404 /* Note that we don't verify it, since the code does not come from user space */ 1405 static int 1406 process_fetch_insn(struct fetch_insn *code, void *rec, void *edata, 1407 void *dest, void *base) 1408 { 1409 struct pt_regs *regs = rec; 1410 unsigned long val; 1411 int ret; 1412 1413 retry: 1414 /* 1st stage: get value from context */ 1415 switch (code->op) { 1416 case FETCH_OP_REG: 1417 val = regs_get_register(regs, code->param); 1418 break; 1419 case FETCH_OP_STACK: 1420 val = regs_get_kernel_stack_nth(regs, code->param); 1421 break; 1422 case FETCH_OP_STACKP: 1423 val = kernel_stack_pointer(regs); 1424 break; 1425 case FETCH_OP_RETVAL: 1426 val = regs_return_value(regs); 1427 break; 1428 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API 1429 case FETCH_OP_ARG: 1430 val = regs_get_kernel_argument(regs, code->param); 1431 break; 1432 case FETCH_OP_EDATA: 1433 val = *(unsigned long *)((unsigned long)edata + code->offset); 1434 break; 1435 #endif 1436 case FETCH_NOP_SYMBOL: /* Ignore a place holder */ 1437 code++; 1438 goto retry; 1439 default: 1440 ret = process_common_fetch_insn(code, &val); 1441 if (ret < 0) 1442 return ret; 1443 } 1444 code++; 1445 1446 return process_fetch_insn_bottom(code, val, dest, base); 1447 } 1448 NOKPROBE_SYMBOL(process_fetch_insn) 1449 1450 /* Kprobe handler */ 1451 static nokprobe_inline void 1452 __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, 1453 struct trace_event_file *trace_file) 1454 { 1455 struct kprobe_trace_entry_head *entry; 1456 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1457 struct trace_event_buffer fbuffer; 1458 int dsize; 1459 1460 WARN_ON(call != trace_file->event_call); 1461 1462 if (trace_trigger_soft_disabled(trace_file)) 1463 return; 1464 1465 dsize = __get_data_size(&tk->tp, regs, NULL); 1466 1467 entry = trace_event_buffer_reserve(&fbuffer, trace_file, 1468 sizeof(*entry) + tk->tp.size + dsize); 1469 if (!entry) 1470 return; 1471 1472 fbuffer.regs = regs; 1473 entry->ip = (unsigned long)tk->rp.kp.addr; 1474 store_trace_args(&entry[1], &tk->tp, regs, NULL, sizeof(*entry), dsize); 1475 1476 trace_event_buffer_commit(&fbuffer); 1477 } 1478 1479 static void 1480 kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) 1481 { 1482 struct event_file_link *link; 1483 1484 trace_probe_for_each_link_rcu(link, &tk->tp) 1485 __kprobe_trace_func(tk, regs, link->file); 1486 } 1487 NOKPROBE_SYMBOL(kprobe_trace_func); 1488 1489 /* Kretprobe handler */ 1490 1491 static int trace_kprobe_entry_handler(struct kretprobe_instance *ri, 1492 struct pt_regs *regs) 1493 { 1494 struct kretprobe *rp = get_kretprobe(ri); 1495 struct trace_kprobe *tk; 1496 1497 /* 1498 * There is a small chance that get_kretprobe(ri) returns NULL when 1499 * the kretprobe is unregister on another CPU between kretprobe's 1500 * trampoline_handler and this function. 1501 */ 1502 if (unlikely(!rp)) 1503 return -ENOENT; 1504 1505 tk = container_of(rp, struct trace_kprobe, rp); 1506 1507 /* store argument values into ri->data as entry data */ 1508 if (tk->tp.entry_arg) 1509 store_trace_entry_data(ri->data, &tk->tp, regs); 1510 1511 return 0; 1512 } 1513 1514 1515 static nokprobe_inline void 1516 __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, 1517 struct pt_regs *regs, 1518 struct trace_event_file *trace_file) 1519 { 1520 struct kretprobe_trace_entry_head *entry; 1521 struct trace_event_buffer fbuffer; 1522 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1523 int dsize; 1524 1525 WARN_ON(call != trace_file->event_call); 1526 1527 if (trace_trigger_soft_disabled(trace_file)) 1528 return; 1529 1530 dsize = __get_data_size(&tk->tp, regs, ri->data); 1531 1532 entry = trace_event_buffer_reserve(&fbuffer, trace_file, 1533 sizeof(*entry) + tk->tp.size + dsize); 1534 if (!entry) 1535 return; 1536 1537 fbuffer.regs = regs; 1538 entry->func = (unsigned long)tk->rp.kp.addr; 1539 entry->ret_ip = get_kretprobe_retaddr(ri); 1540 store_trace_args(&entry[1], &tk->tp, regs, ri->data, sizeof(*entry), dsize); 1541 1542 trace_event_buffer_commit(&fbuffer); 1543 } 1544 1545 static void 1546 kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, 1547 struct pt_regs *regs) 1548 { 1549 struct event_file_link *link; 1550 1551 trace_probe_for_each_link_rcu(link, &tk->tp) 1552 __kretprobe_trace_func(tk, ri, regs, link->file); 1553 } 1554 NOKPROBE_SYMBOL(kretprobe_trace_func); 1555 1556 /* Event entry printers */ 1557 static enum print_line_t 1558 print_kprobe_event(struct trace_iterator *iter, int flags, 1559 struct trace_event *event) 1560 { 1561 struct kprobe_trace_entry_head *field; 1562 struct trace_seq *s = &iter->seq; 1563 struct trace_probe *tp; 1564 1565 field = (struct kprobe_trace_entry_head *)iter->ent; 1566 tp = trace_probe_primary_from_call( 1567 container_of(event, struct trace_event_call, event)); 1568 if (WARN_ON_ONCE(!tp)) 1569 goto out; 1570 1571 trace_seq_printf(s, "%s: (", trace_probe_name(tp)); 1572 1573 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) 1574 goto out; 1575 1576 trace_seq_putc(s, ')'); 1577 1578 if (trace_probe_print_args(s, tp->args, tp->nr_args, 1579 (u8 *)&field[1], field) < 0) 1580 goto out; 1581 1582 trace_seq_putc(s, '\n'); 1583 out: 1584 return trace_handle_return(s); 1585 } 1586 1587 static enum print_line_t 1588 print_kretprobe_event(struct trace_iterator *iter, int flags, 1589 struct trace_event *event) 1590 { 1591 struct kretprobe_trace_entry_head *field; 1592 struct trace_seq *s = &iter->seq; 1593 struct trace_probe *tp; 1594 1595 field = (struct kretprobe_trace_entry_head *)iter->ent; 1596 tp = trace_probe_primary_from_call( 1597 container_of(event, struct trace_event_call, event)); 1598 if (WARN_ON_ONCE(!tp)) 1599 goto out; 1600 1601 trace_seq_printf(s, "%s: (", trace_probe_name(tp)); 1602 1603 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) 1604 goto out; 1605 1606 trace_seq_puts(s, " <- "); 1607 1608 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) 1609 goto out; 1610 1611 trace_seq_putc(s, ')'); 1612 1613 if (trace_probe_print_args(s, tp->args, tp->nr_args, 1614 (u8 *)&field[1], field) < 0) 1615 goto out; 1616 1617 trace_seq_putc(s, '\n'); 1618 1619 out: 1620 return trace_handle_return(s); 1621 } 1622 1623 1624 static int kprobe_event_define_fields(struct trace_event_call *event_call) 1625 { 1626 int ret; 1627 struct kprobe_trace_entry_head field; 1628 struct trace_probe *tp; 1629 1630 tp = trace_probe_primary_from_call(event_call); 1631 if (WARN_ON_ONCE(!tp)) 1632 return -ENOENT; 1633 1634 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); 1635 1636 return traceprobe_define_arg_fields(event_call, sizeof(field), tp); 1637 } 1638 1639 static int kretprobe_event_define_fields(struct trace_event_call *event_call) 1640 { 1641 int ret; 1642 struct kretprobe_trace_entry_head field; 1643 struct trace_probe *tp; 1644 1645 tp = trace_probe_primary_from_call(event_call); 1646 if (WARN_ON_ONCE(!tp)) 1647 return -ENOENT; 1648 1649 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); 1650 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); 1651 1652 return traceprobe_define_arg_fields(event_call, sizeof(field), tp); 1653 } 1654 1655 #ifdef CONFIG_PERF_EVENTS 1656 1657 /* Kprobe profile handler */ 1658 static int 1659 kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) 1660 { 1661 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1662 struct kprobe_trace_entry_head *entry; 1663 struct hlist_head *head; 1664 int size, __size, dsize; 1665 int rctx; 1666 1667 if (bpf_prog_array_valid(call)) { 1668 unsigned long orig_ip = instruction_pointer(regs); 1669 int ret; 1670 1671 ret = trace_call_bpf(call, regs); 1672 1673 /* 1674 * We need to check and see if we modified the pc of the 1675 * pt_regs, and if so return 1 so that we don't do the 1676 * single stepping. 1677 */ 1678 if (orig_ip != instruction_pointer(regs)) 1679 return 1; 1680 if (!ret) 1681 return 0; 1682 } 1683 1684 head = this_cpu_ptr(call->perf_events); 1685 if (hlist_empty(head)) 1686 return 0; 1687 1688 dsize = __get_data_size(&tk->tp, regs, NULL); 1689 __size = sizeof(*entry) + tk->tp.size + dsize; 1690 size = ALIGN(__size + sizeof(u32), sizeof(u64)); 1691 size -= sizeof(u32); 1692 1693 entry = perf_trace_buf_alloc(size, NULL, &rctx); 1694 if (!entry) 1695 return 0; 1696 1697 entry->ip = (unsigned long)tk->rp.kp.addr; 1698 memset(&entry[1], 0, dsize); 1699 store_trace_args(&entry[1], &tk->tp, regs, NULL, sizeof(*entry), dsize); 1700 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, 1701 head, NULL); 1702 return 0; 1703 } 1704 NOKPROBE_SYMBOL(kprobe_perf_func); 1705 1706 /* Kretprobe profile handler */ 1707 static void 1708 kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, 1709 struct pt_regs *regs) 1710 { 1711 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1712 struct kretprobe_trace_entry_head *entry; 1713 struct hlist_head *head; 1714 int size, __size, dsize; 1715 int rctx; 1716 1717 if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs)) 1718 return; 1719 1720 head = this_cpu_ptr(call->perf_events); 1721 if (hlist_empty(head)) 1722 return; 1723 1724 dsize = __get_data_size(&tk->tp, regs, ri->data); 1725 __size = sizeof(*entry) + tk->tp.size + dsize; 1726 size = ALIGN(__size + sizeof(u32), sizeof(u64)); 1727 size -= sizeof(u32); 1728 1729 entry = perf_trace_buf_alloc(size, NULL, &rctx); 1730 if (!entry) 1731 return; 1732 1733 entry->func = (unsigned long)tk->rp.kp.addr; 1734 entry->ret_ip = get_kretprobe_retaddr(ri); 1735 store_trace_args(&entry[1], &tk->tp, regs, ri->data, sizeof(*entry), dsize); 1736 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, 1737 head, NULL); 1738 } 1739 NOKPROBE_SYMBOL(kretprobe_perf_func); 1740 1741 int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type, 1742 const char **symbol, u64 *probe_offset, 1743 u64 *probe_addr, unsigned long *missed, 1744 bool perf_type_tracepoint) 1745 { 1746 const char *pevent = trace_event_name(event->tp_event); 1747 const char *group = event->tp_event->class->system; 1748 struct trace_kprobe *tk; 1749 1750 if (perf_type_tracepoint) 1751 tk = find_trace_kprobe(pevent, group); 1752 else 1753 tk = trace_kprobe_primary_from_call(event->tp_event); 1754 if (!tk) 1755 return -EINVAL; 1756 1757 *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE 1758 : BPF_FD_TYPE_KPROBE; 1759 *probe_offset = tk->rp.kp.offset; 1760 *probe_addr = kallsyms_show_value(current_cred()) ? 1761 (unsigned long)tk->rp.kp.addr : 0; 1762 *symbol = tk->symbol; 1763 if (missed) 1764 *missed = trace_kprobe_missed(tk); 1765 return 0; 1766 } 1767 #endif /* CONFIG_PERF_EVENTS */ 1768 1769 /* 1770 * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. 1771 * 1772 * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe 1773 * lockless, but we can't race with this __init function. 1774 */ 1775 static int kprobe_register(struct trace_event_call *event, 1776 enum trace_reg type, void *data) 1777 { 1778 struct trace_event_file *file = data; 1779 1780 switch (type) { 1781 case TRACE_REG_REGISTER: 1782 return enable_trace_kprobe(event, file); 1783 case TRACE_REG_UNREGISTER: 1784 return disable_trace_kprobe(event, file); 1785 1786 #ifdef CONFIG_PERF_EVENTS 1787 case TRACE_REG_PERF_REGISTER: 1788 return enable_trace_kprobe(event, NULL); 1789 case TRACE_REG_PERF_UNREGISTER: 1790 return disable_trace_kprobe(event, NULL); 1791 case TRACE_REG_PERF_OPEN: 1792 case TRACE_REG_PERF_CLOSE: 1793 case TRACE_REG_PERF_ADD: 1794 case TRACE_REG_PERF_DEL: 1795 return 0; 1796 #endif 1797 } 1798 return 0; 1799 } 1800 1801 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) 1802 { 1803 struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); 1804 int ret = 0; 1805 1806 raw_cpu_inc(*tk->nhit); 1807 1808 if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) 1809 kprobe_trace_func(tk, regs); 1810 #ifdef CONFIG_PERF_EVENTS 1811 if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) 1812 ret = kprobe_perf_func(tk, regs); 1813 #endif 1814 return ret; 1815 } 1816 NOKPROBE_SYMBOL(kprobe_dispatcher); 1817 1818 static int 1819 kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) 1820 { 1821 struct kretprobe *rp = get_kretprobe(ri); 1822 struct trace_kprobe *tk; 1823 1824 /* 1825 * There is a small chance that get_kretprobe(ri) returns NULL when 1826 * the kretprobe is unregister on another CPU between kretprobe's 1827 * trampoline_handler and this function. 1828 */ 1829 if (unlikely(!rp)) 1830 return 0; 1831 1832 tk = container_of(rp, struct trace_kprobe, rp); 1833 raw_cpu_inc(*tk->nhit); 1834 1835 if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) 1836 kretprobe_trace_func(tk, ri, regs); 1837 #ifdef CONFIG_PERF_EVENTS 1838 if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) 1839 kretprobe_perf_func(tk, ri, regs); 1840 #endif 1841 return 0; /* We don't tweak kernel, so just return 0 */ 1842 } 1843 NOKPROBE_SYMBOL(kretprobe_dispatcher); 1844 1845 static struct trace_event_functions kretprobe_funcs = { 1846 .trace = print_kretprobe_event 1847 }; 1848 1849 static struct trace_event_functions kprobe_funcs = { 1850 .trace = print_kprobe_event 1851 }; 1852 1853 static struct trace_event_fields kretprobe_fields_array[] = { 1854 { .type = TRACE_FUNCTION_TYPE, 1855 .define_fields = kretprobe_event_define_fields }, 1856 {} 1857 }; 1858 1859 static struct trace_event_fields kprobe_fields_array[] = { 1860 { .type = TRACE_FUNCTION_TYPE, 1861 .define_fields = kprobe_event_define_fields }, 1862 {} 1863 }; 1864 1865 static inline void init_trace_event_call(struct trace_kprobe *tk) 1866 { 1867 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1868 1869 if (trace_kprobe_is_return(tk)) { 1870 call->event.funcs = &kretprobe_funcs; 1871 call->class->fields_array = kretprobe_fields_array; 1872 } else { 1873 call->event.funcs = &kprobe_funcs; 1874 call->class->fields_array = kprobe_fields_array; 1875 } 1876 1877 call->flags = TRACE_EVENT_FL_KPROBE; 1878 call->class->reg = kprobe_register; 1879 } 1880 1881 static int register_kprobe_event(struct trace_kprobe *tk) 1882 { 1883 init_trace_event_call(tk); 1884 1885 return trace_probe_register_event_call(&tk->tp); 1886 } 1887 1888 static int unregister_kprobe_event(struct trace_kprobe *tk) 1889 { 1890 return trace_probe_unregister_event_call(&tk->tp); 1891 } 1892 1893 #ifdef CONFIG_PERF_EVENTS 1894 1895 /* create a trace_kprobe, but don't add it to global lists */ 1896 struct trace_event_call * 1897 create_local_trace_kprobe(char *func, void *addr, unsigned long offs, 1898 bool is_return) 1899 { 1900 enum probe_print_type ptype; 1901 struct trace_kprobe *tk __free(free_trace_kprobe) = NULL; 1902 int ret; 1903 char *event; 1904 1905 if (func) { 1906 ret = validate_probe_symbol(func); 1907 if (ret) 1908 return ERR_PTR(ret); 1909 } 1910 1911 /* 1912 * local trace_kprobes are not added to dyn_event, so they are never 1913 * searched in find_trace_kprobe(). Therefore, there is no concern of 1914 * duplicated name here. 1915 */ 1916 event = func ? func : "DUMMY_EVENT"; 1917 1918 tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func, 1919 offs, 0 /* maxactive */, 0 /* nargs */, 1920 is_return); 1921 1922 if (IS_ERR(tk)) { 1923 pr_info("Failed to allocate trace_probe.(%d)\n", 1924 (int)PTR_ERR(tk)); 1925 return ERR_CAST(tk); 1926 } 1927 1928 init_trace_event_call(tk); 1929 1930 ptype = trace_kprobe_is_return(tk) ? 1931 PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; 1932 if (traceprobe_set_print_fmt(&tk->tp, ptype) < 0) 1933 return ERR_PTR(-ENOMEM); 1934 1935 ret = __register_trace_kprobe(tk); 1936 if (ret < 0) 1937 return ERR_PTR(ret); 1938 1939 return trace_probe_event_call(&(no_free_ptr(tk)->tp)); 1940 } 1941 1942 void destroy_local_trace_kprobe(struct trace_event_call *event_call) 1943 { 1944 struct trace_kprobe *tk; 1945 1946 tk = trace_kprobe_primary_from_call(event_call); 1947 if (unlikely(!tk)) 1948 return; 1949 1950 if (trace_probe_is_enabled(&tk->tp)) { 1951 WARN_ON(1); 1952 return; 1953 } 1954 1955 __unregister_trace_kprobe(tk); 1956 1957 free_trace_kprobe(tk); 1958 } 1959 #endif /* CONFIG_PERF_EVENTS */ 1960 1961 static __init void enable_boot_kprobe_events(void) 1962 { 1963 struct trace_array *tr = top_trace_array(); 1964 struct trace_event_file *file; 1965 struct trace_kprobe *tk; 1966 struct dyn_event *pos; 1967 1968 guard(mutex)(&event_mutex); 1969 for_each_trace_kprobe(tk, pos) { 1970 list_for_each_entry(file, &tr->events, list) 1971 if (file->event_call == trace_probe_event_call(&tk->tp)) 1972 trace_event_enable_disable(file, 1, 0); 1973 } 1974 } 1975 1976 static __init void setup_boot_kprobe_events(void) 1977 { 1978 char *p, *cmd = kprobe_boot_events_buf; 1979 int ret; 1980 1981 strreplace(kprobe_boot_events_buf, ',', ' '); 1982 1983 while (cmd && *cmd != '\0') { 1984 p = strchr(cmd, ';'); 1985 if (p) 1986 *p++ = '\0'; 1987 1988 ret = create_or_delete_trace_kprobe(cmd); 1989 if (ret) 1990 pr_warn("Failed to add event(%d): %s\n", ret, cmd); 1991 1992 cmd = p; 1993 } 1994 1995 enable_boot_kprobe_events(); 1996 } 1997 1998 /* 1999 * Register dynevent at core_initcall. This allows kernel to setup kprobe 2000 * events in postcore_initcall without tracefs. 2001 */ 2002 static __init int init_kprobe_trace_early(void) 2003 { 2004 int ret; 2005 2006 ret = dyn_event_register(&trace_kprobe_ops); 2007 if (ret) 2008 return ret; 2009 2010 if (trace_kprobe_register_module_notifier()) 2011 return -EINVAL; 2012 2013 return 0; 2014 } 2015 core_initcall(init_kprobe_trace_early); 2016 2017 /* Make a tracefs interface for controlling probe points */ 2018 static __init int init_kprobe_trace(void) 2019 { 2020 int ret; 2021 2022 ret = tracing_init_dentry(); 2023 if (ret) 2024 return 0; 2025 2026 /* Event list interface */ 2027 trace_create_file("kprobe_events", TRACE_MODE_WRITE, 2028 NULL, NULL, &kprobe_events_ops); 2029 2030 /* Profile interface */ 2031 trace_create_file("kprobe_profile", TRACE_MODE_READ, 2032 NULL, NULL, &kprobe_profile_ops); 2033 2034 setup_boot_kprobe_events(); 2035 2036 return 0; 2037 } 2038 fs_initcall(init_kprobe_trace); 2039 2040 2041 #ifdef CONFIG_FTRACE_STARTUP_TEST 2042 static __init struct trace_event_file * 2043 find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) 2044 { 2045 struct trace_event_file *file; 2046 2047 list_for_each_entry(file, &tr->events, list) 2048 if (file->event_call == trace_probe_event_call(&tk->tp)) 2049 return file; 2050 2051 return NULL; 2052 } 2053 2054 /* 2055 * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this 2056 * stage, we can do this lockless. 2057 */ 2058 static __init int kprobe_trace_self_tests_init(void) 2059 { 2060 int ret, warn = 0; 2061 int (*target)(int, int, int, int, int, int); 2062 struct trace_kprobe *tk; 2063 struct trace_event_file *file; 2064 2065 if (tracing_is_disabled()) 2066 return -ENODEV; 2067 2068 if (tracing_selftest_disabled) 2069 return 0; 2070 2071 target = kprobe_trace_selftest_target; 2072 2073 pr_info("Testing kprobe tracing: "); 2074 2075 ret = create_or_delete_trace_kprobe("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)"); 2076 if (WARN_ONCE(ret, "error on probing function entry.")) { 2077 warn++; 2078 } else { 2079 /* Enable trace point */ 2080 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); 2081 if (WARN_ONCE(tk == NULL, "error on probing function entry.")) { 2082 warn++; 2083 } else { 2084 file = find_trace_probe_file(tk, top_trace_array()); 2085 if (WARN_ONCE(file == NULL, "error on getting probe file.")) { 2086 warn++; 2087 } else 2088 enable_trace_kprobe( 2089 trace_probe_event_call(&tk->tp), file); 2090 } 2091 } 2092 2093 ret = create_or_delete_trace_kprobe("r:testprobe2 kprobe_trace_selftest_target $retval"); 2094 if (WARN_ONCE(ret, "error on probing function return.")) { 2095 warn++; 2096 } else { 2097 /* Enable trace point */ 2098 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); 2099 if (WARN_ONCE(tk == NULL, "error on getting 2nd new probe.")) { 2100 warn++; 2101 } else { 2102 file = find_trace_probe_file(tk, top_trace_array()); 2103 if (WARN_ONCE(file == NULL, "error on getting probe file.")) { 2104 warn++; 2105 } else 2106 enable_trace_kprobe( 2107 trace_probe_event_call(&tk->tp), file); 2108 } 2109 } 2110 2111 if (warn) 2112 goto end; 2113 2114 ret = target(1, 2, 3, 4, 5, 6); 2115 2116 /* 2117 * Not expecting an error here, the check is only to prevent the 2118 * optimizer from removing the call to target() as otherwise there 2119 * are no side-effects and the call is never performed. 2120 */ 2121 if (ret != 21) 2122 warn++; 2123 2124 /* Disable trace points before removing it */ 2125 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); 2126 if (WARN_ONCE(tk == NULL, "error on getting test probe.")) { 2127 warn++; 2128 } else { 2129 if (WARN_ONCE(trace_kprobe_nhit(tk) != 1, 2130 "incorrect number of testprobe hits.")) 2131 warn++; 2132 2133 file = find_trace_probe_file(tk, top_trace_array()); 2134 if (WARN_ONCE(file == NULL, "error on getting probe file.")) { 2135 warn++; 2136 } else 2137 disable_trace_kprobe( 2138 trace_probe_event_call(&tk->tp), file); 2139 } 2140 2141 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); 2142 if (WARN_ONCE(tk == NULL, "error on getting 2nd test probe.")) { 2143 warn++; 2144 } else { 2145 if (WARN_ONCE(trace_kprobe_nhit(tk) != 1, 2146 "incorrect number of testprobe2 hits.")) 2147 warn++; 2148 2149 file = find_trace_probe_file(tk, top_trace_array()); 2150 if (WARN_ONCE(file == NULL, "error on getting probe file.")) { 2151 warn++; 2152 } else 2153 disable_trace_kprobe( 2154 trace_probe_event_call(&tk->tp), file); 2155 } 2156 2157 ret = create_or_delete_trace_kprobe("-:testprobe"); 2158 if (WARN_ONCE(ret, "error on deleting a probe.")) 2159 warn++; 2160 2161 ret = create_or_delete_trace_kprobe("-:testprobe2"); 2162 if (WARN_ONCE(ret, "error on deleting a probe.")) 2163 warn++; 2164 2165 2166 end: 2167 /* 2168 * Wait for the optimizer work to finish. Otherwise it might fiddle 2169 * with probes in already freed __init text. 2170 */ 2171 wait_for_kprobe_optimizer(); 2172 if (warn) 2173 pr_cont("NG: Some tests are failed. Please check them.\n"); 2174 else 2175 pr_cont("OK\n"); 2176 return 0; 2177 } 2178 2179 late_initcall(kprobe_trace_self_tests_init); 2180 2181 #endif 2182