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 return -E2BIG; 1012 1013 ret = traceprobe_expand_dentry_args(argc, argv, &dbuf); 1014 if (ret) 1015 return ret; 1016 1017 /* setup a probe */ 1018 tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive, 1019 argc, is_return); 1020 if (IS_ERR(tk)) { 1021 ret = PTR_ERR(tk); 1022 /* This must return -ENOMEM, else there is a bug */ 1023 WARN_ON_ONCE(ret != -ENOMEM); 1024 return ret; /* We know tk is not allocated */ 1025 } 1026 1027 /* parse arguments */ 1028 for (i = 0; i < argc; i++) { 1029 trace_probe_log_set_index(i + 2); 1030 ctx->offset = 0; 1031 ret = traceprobe_parse_probe_arg(&tk->tp, i, argv[i], ctx); 1032 if (ret) 1033 return ret; /* This can be -ENOMEM */ 1034 } 1035 /* entry handler for kretprobe */ 1036 if (is_return && tk->tp.entry_arg) { 1037 tk->rp.entry_handler = trace_kprobe_entry_handler; 1038 tk->rp.data_size = traceprobe_get_entry_data_size(&tk->tp); 1039 } 1040 1041 ptype = is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; 1042 ret = traceprobe_set_print_fmt(&tk->tp, ptype); 1043 if (ret < 0) 1044 return ret; 1045 1046 ret = register_trace_kprobe(tk); 1047 if (ret) { 1048 trace_probe_log_set_index(1); 1049 if (ret == -EILSEQ) 1050 trace_probe_log_err(0, BAD_INSN_BNDRY); 1051 else if (ret == -ENOENT) 1052 trace_probe_log_err(0, BAD_PROBE_ADDR); 1053 else if (ret != -ENOMEM && ret != -EEXIST) 1054 trace_probe_log_err(0, FAIL_REG_PROBE); 1055 return ret; 1056 } 1057 /* 1058 * Here, 'tk' has been registered to the list successfully, 1059 * so we don't need to free it. 1060 */ 1061 tk = NULL; 1062 1063 return 0; 1064 } 1065 1066 static int trace_kprobe_create_cb(int argc, const char *argv[]) 1067 { 1068 struct traceprobe_parse_context ctx = { .flags = TPARG_FL_KERNEL }; 1069 int ret; 1070 1071 trace_probe_log_init("trace_kprobe", argc, argv); 1072 1073 ret = trace_kprobe_create_internal(argc, argv, &ctx); 1074 1075 traceprobe_finish_parse(&ctx); 1076 trace_probe_log_clear(); 1077 return ret; 1078 } 1079 1080 static int trace_kprobe_create(const char *raw_command) 1081 { 1082 return trace_probe_create(raw_command, trace_kprobe_create_cb); 1083 } 1084 1085 static int create_or_delete_trace_kprobe(const char *raw_command) 1086 { 1087 int ret; 1088 1089 if (raw_command[0] == '-') 1090 return dyn_event_release(raw_command, &trace_kprobe_ops); 1091 1092 ret = trace_kprobe_create(raw_command); 1093 return ret == -ECANCELED ? -EINVAL : ret; 1094 } 1095 1096 static int trace_kprobe_run_command(struct dynevent_cmd *cmd) 1097 { 1098 return create_or_delete_trace_kprobe(cmd->seq.buffer); 1099 } 1100 1101 /** 1102 * kprobe_event_cmd_init - Initialize a kprobe event command object 1103 * @cmd: A pointer to the dynevent_cmd struct representing the new event 1104 * @buf: A pointer to the buffer used to build the command 1105 * @maxlen: The length of the buffer passed in @buf 1106 * 1107 * Initialize a synthetic event command object. Use this before 1108 * calling any of the other kprobe_event functions. 1109 */ 1110 void kprobe_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen) 1111 { 1112 dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_KPROBE, 1113 trace_kprobe_run_command); 1114 } 1115 EXPORT_SYMBOL_GPL(kprobe_event_cmd_init); 1116 1117 /** 1118 * __kprobe_event_gen_cmd_start - Generate a kprobe event command from arg list 1119 * @cmd: A pointer to the dynevent_cmd struct representing the new event 1120 * @kretprobe: Is this a return probe? 1121 * @name: The name of the kprobe event 1122 * @loc: The location of the kprobe event 1123 * @...: Variable number of arg (pairs), one pair for each field 1124 * 1125 * NOTE: Users normally won't want to call this function directly, but 1126 * rather use the kprobe_event_gen_cmd_start() wrapper, which automatically 1127 * adds a NULL to the end of the arg list. If this function is used 1128 * directly, make sure the last arg in the variable arg list is NULL. 1129 * 1130 * Generate a kprobe event command to be executed by 1131 * kprobe_event_gen_cmd_end(). This function can be used to generate the 1132 * complete command or only the first part of it; in the latter case, 1133 * kprobe_event_add_fields() can be used to add more fields following this. 1134 * 1135 * Unlikely the synth_event_gen_cmd_start(), @loc must be specified. This 1136 * returns -EINVAL if @loc == NULL. 1137 * 1138 * Return: 0 if successful, error otherwise. 1139 */ 1140 int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe, 1141 const char *name, const char *loc, ...) 1142 { 1143 char buf[MAX_EVENT_NAME_LEN]; 1144 struct dynevent_arg arg; 1145 va_list args; 1146 int ret; 1147 1148 if (cmd->type != DYNEVENT_TYPE_KPROBE) 1149 return -EINVAL; 1150 1151 if (!loc) 1152 return -EINVAL; 1153 1154 if (kretprobe) 1155 snprintf(buf, MAX_EVENT_NAME_LEN, "r:kprobes/%s", name); 1156 else 1157 snprintf(buf, MAX_EVENT_NAME_LEN, "p:kprobes/%s", name); 1158 1159 ret = dynevent_str_add(cmd, buf); 1160 if (ret) 1161 return ret; 1162 1163 dynevent_arg_init(&arg, 0); 1164 arg.str = loc; 1165 ret = dynevent_arg_add(cmd, &arg, NULL); 1166 if (ret) 1167 return ret; 1168 1169 va_start(args, loc); 1170 for (;;) { 1171 const char *field; 1172 1173 field = va_arg(args, const char *); 1174 if (!field) 1175 break; 1176 1177 if (++cmd->n_fields > MAX_TRACE_ARGS) { 1178 ret = -EINVAL; 1179 break; 1180 } 1181 1182 arg.str = field; 1183 ret = dynevent_arg_add(cmd, &arg, NULL); 1184 if (ret) 1185 break; 1186 } 1187 va_end(args); 1188 1189 return ret; 1190 } 1191 EXPORT_SYMBOL_GPL(__kprobe_event_gen_cmd_start); 1192 1193 /** 1194 * __kprobe_event_add_fields - Add probe fields to a kprobe command from arg list 1195 * @cmd: A pointer to the dynevent_cmd struct representing the new event 1196 * @...: Variable number of arg (pairs), one pair for each field 1197 * 1198 * NOTE: Users normally won't want to call this function directly, but 1199 * rather use the kprobe_event_add_fields() wrapper, which 1200 * automatically adds a NULL to the end of the arg list. If this 1201 * function is used directly, make sure the last arg in the variable 1202 * arg list is NULL. 1203 * 1204 * Add probe fields to an existing kprobe command using a variable 1205 * list of args. Fields are added in the same order they're listed. 1206 * 1207 * Return: 0 if successful, error otherwise. 1208 */ 1209 int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...) 1210 { 1211 struct dynevent_arg arg; 1212 va_list args; 1213 int ret = 0; 1214 1215 if (cmd->type != DYNEVENT_TYPE_KPROBE) 1216 return -EINVAL; 1217 1218 dynevent_arg_init(&arg, 0); 1219 1220 va_start(args, cmd); 1221 for (;;) { 1222 const char *field; 1223 1224 field = va_arg(args, const char *); 1225 if (!field) 1226 break; 1227 1228 if (++cmd->n_fields > MAX_TRACE_ARGS) { 1229 ret = -EINVAL; 1230 break; 1231 } 1232 1233 arg.str = field; 1234 ret = dynevent_arg_add(cmd, &arg, NULL); 1235 if (ret) 1236 break; 1237 } 1238 va_end(args); 1239 1240 return ret; 1241 } 1242 EXPORT_SYMBOL_GPL(__kprobe_event_add_fields); 1243 1244 /** 1245 * kprobe_event_delete - Delete a kprobe event 1246 * @name: The name of the kprobe event to delete 1247 * 1248 * Delete a kprobe event with the give @name from kernel code rather 1249 * than directly from the command line. 1250 * 1251 * Return: 0 if successful, error otherwise. 1252 */ 1253 int kprobe_event_delete(const char *name) 1254 { 1255 char buf[MAX_EVENT_NAME_LEN]; 1256 1257 snprintf(buf, MAX_EVENT_NAME_LEN, "-:%s", name); 1258 1259 return create_or_delete_trace_kprobe(buf); 1260 } 1261 EXPORT_SYMBOL_GPL(kprobe_event_delete); 1262 1263 static int trace_kprobe_release(struct dyn_event *ev) 1264 { 1265 struct trace_kprobe *tk = to_trace_kprobe(ev); 1266 int ret = unregister_trace_kprobe(tk); 1267 1268 if (!ret) 1269 free_trace_kprobe(tk); 1270 return ret; 1271 } 1272 1273 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev) 1274 { 1275 struct trace_kprobe *tk = to_trace_kprobe(ev); 1276 int i; 1277 1278 seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p'); 1279 if (trace_kprobe_is_return(tk) && tk->rp.maxactive) 1280 seq_printf(m, "%d", tk->rp.maxactive); 1281 seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp), 1282 trace_probe_name(&tk->tp)); 1283 1284 if (!tk->symbol) 1285 seq_printf(m, " 0x%p", tk->rp.kp.addr); 1286 else if (tk->rp.kp.offset) 1287 seq_printf(m, " %s+%u", trace_kprobe_symbol(tk), 1288 tk->rp.kp.offset); 1289 else 1290 seq_printf(m, " %s", trace_kprobe_symbol(tk)); 1291 1292 for (i = 0; i < tk->tp.nr_args; i++) 1293 seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm); 1294 seq_putc(m, '\n'); 1295 1296 return 0; 1297 } 1298 1299 static int probes_seq_show(struct seq_file *m, void *v) 1300 { 1301 struct dyn_event *ev = v; 1302 1303 if (!is_trace_kprobe(ev)) 1304 return 0; 1305 1306 return trace_kprobe_show(m, ev); 1307 } 1308 1309 static const struct seq_operations probes_seq_op = { 1310 .start = dyn_event_seq_start, 1311 .next = dyn_event_seq_next, 1312 .stop = dyn_event_seq_stop, 1313 .show = probes_seq_show 1314 }; 1315 1316 static int probes_open(struct inode *inode, struct file *file) 1317 { 1318 int ret; 1319 1320 ret = security_locked_down(LOCKDOWN_TRACEFS); 1321 if (ret) 1322 return ret; 1323 1324 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { 1325 ret = dyn_events_release_all(&trace_kprobe_ops); 1326 if (ret < 0) 1327 return ret; 1328 } 1329 1330 return seq_open(file, &probes_seq_op); 1331 } 1332 1333 static ssize_t probes_write(struct file *file, const char __user *buffer, 1334 size_t count, loff_t *ppos) 1335 { 1336 return trace_parse_run_command(file, buffer, count, ppos, 1337 create_or_delete_trace_kprobe); 1338 } 1339 1340 static const struct file_operations kprobe_events_ops = { 1341 .owner = THIS_MODULE, 1342 .open = probes_open, 1343 .read = seq_read, 1344 .llseek = seq_lseek, 1345 .release = seq_release, 1346 .write = probes_write, 1347 }; 1348 1349 static unsigned long trace_kprobe_missed(struct trace_kprobe *tk) 1350 { 1351 return trace_kprobe_is_return(tk) ? 1352 tk->rp.kp.nmissed + tk->rp.nmissed : tk->rp.kp.nmissed; 1353 } 1354 1355 /* Probes profiling interfaces */ 1356 static int probes_profile_seq_show(struct seq_file *m, void *v) 1357 { 1358 struct dyn_event *ev = v; 1359 struct trace_kprobe *tk; 1360 unsigned long nmissed; 1361 1362 if (!is_trace_kprobe(ev)) 1363 return 0; 1364 1365 tk = to_trace_kprobe(ev); 1366 nmissed = trace_kprobe_missed(tk); 1367 seq_printf(m, " %-44s %15lu %15lu\n", 1368 trace_probe_name(&tk->tp), 1369 trace_kprobe_nhit(tk), 1370 nmissed); 1371 1372 return 0; 1373 } 1374 1375 static const struct seq_operations profile_seq_op = { 1376 .start = dyn_event_seq_start, 1377 .next = dyn_event_seq_next, 1378 .stop = dyn_event_seq_stop, 1379 .show = probes_profile_seq_show 1380 }; 1381 1382 static int profile_open(struct inode *inode, struct file *file) 1383 { 1384 int ret; 1385 1386 ret = security_locked_down(LOCKDOWN_TRACEFS); 1387 if (ret) 1388 return ret; 1389 1390 return seq_open(file, &profile_seq_op); 1391 } 1392 1393 static const struct file_operations kprobe_profile_ops = { 1394 .owner = THIS_MODULE, 1395 .open = profile_open, 1396 .read = seq_read, 1397 .llseek = seq_lseek, 1398 .release = seq_release, 1399 }; 1400 1401 /* Note that we don't verify it, since the code does not come from user space */ 1402 static int 1403 process_fetch_insn(struct fetch_insn *code, void *rec, void *edata, 1404 void *dest, void *base) 1405 { 1406 struct pt_regs *regs = rec; 1407 unsigned long val; 1408 int ret; 1409 1410 retry: 1411 /* 1st stage: get value from context */ 1412 switch (code->op) { 1413 case FETCH_OP_REG: 1414 val = regs_get_register(regs, code->param); 1415 break; 1416 case FETCH_OP_STACK: 1417 val = regs_get_kernel_stack_nth(regs, code->param); 1418 break; 1419 case FETCH_OP_STACKP: 1420 val = kernel_stack_pointer(regs); 1421 break; 1422 case FETCH_OP_RETVAL: 1423 val = regs_return_value(regs); 1424 break; 1425 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API 1426 case FETCH_OP_ARG: 1427 val = regs_get_kernel_argument(regs, code->param); 1428 break; 1429 case FETCH_OP_EDATA: 1430 val = *(unsigned long *)((unsigned long)edata + code->offset); 1431 break; 1432 #endif 1433 case FETCH_NOP_SYMBOL: /* Ignore a place holder */ 1434 code++; 1435 goto retry; 1436 default: 1437 ret = process_common_fetch_insn(code, &val); 1438 if (ret < 0) 1439 return ret; 1440 } 1441 code++; 1442 1443 return process_fetch_insn_bottom(code, val, dest, base); 1444 } 1445 NOKPROBE_SYMBOL(process_fetch_insn) 1446 1447 /* Kprobe handler */ 1448 static nokprobe_inline void 1449 __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, 1450 struct trace_event_file *trace_file) 1451 { 1452 struct kprobe_trace_entry_head *entry; 1453 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1454 struct trace_event_buffer fbuffer; 1455 int dsize; 1456 1457 WARN_ON(call != trace_file->event_call); 1458 1459 if (trace_trigger_soft_disabled(trace_file)) 1460 return; 1461 1462 dsize = __get_data_size(&tk->tp, regs, NULL); 1463 1464 entry = trace_event_buffer_reserve(&fbuffer, trace_file, 1465 sizeof(*entry) + tk->tp.size + dsize); 1466 if (!entry) 1467 return; 1468 1469 fbuffer.regs = regs; 1470 entry->ip = (unsigned long)tk->rp.kp.addr; 1471 store_trace_args(&entry[1], &tk->tp, regs, NULL, sizeof(*entry), dsize); 1472 1473 trace_event_buffer_commit(&fbuffer); 1474 } 1475 1476 static void 1477 kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) 1478 { 1479 struct event_file_link *link; 1480 1481 trace_probe_for_each_link_rcu(link, &tk->tp) 1482 __kprobe_trace_func(tk, regs, link->file); 1483 } 1484 NOKPROBE_SYMBOL(kprobe_trace_func); 1485 1486 /* Kretprobe handler */ 1487 1488 static int trace_kprobe_entry_handler(struct kretprobe_instance *ri, 1489 struct pt_regs *regs) 1490 { 1491 struct kretprobe *rp = get_kretprobe(ri); 1492 struct trace_kprobe *tk; 1493 1494 /* 1495 * There is a small chance that get_kretprobe(ri) returns NULL when 1496 * the kretprobe is unregister on another CPU between kretprobe's 1497 * trampoline_handler and this function. 1498 */ 1499 if (unlikely(!rp)) 1500 return -ENOENT; 1501 1502 tk = container_of(rp, struct trace_kprobe, rp); 1503 1504 /* store argument values into ri->data as entry data */ 1505 if (tk->tp.entry_arg) 1506 store_trace_entry_data(ri->data, &tk->tp, regs); 1507 1508 return 0; 1509 } 1510 1511 1512 static nokprobe_inline void 1513 __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, 1514 struct pt_regs *regs, 1515 struct trace_event_file *trace_file) 1516 { 1517 struct kretprobe_trace_entry_head *entry; 1518 struct trace_event_buffer fbuffer; 1519 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1520 int dsize; 1521 1522 WARN_ON(call != trace_file->event_call); 1523 1524 if (trace_trigger_soft_disabled(trace_file)) 1525 return; 1526 1527 dsize = __get_data_size(&tk->tp, regs, ri->data); 1528 1529 entry = trace_event_buffer_reserve(&fbuffer, trace_file, 1530 sizeof(*entry) + tk->tp.size + dsize); 1531 if (!entry) 1532 return; 1533 1534 fbuffer.regs = regs; 1535 entry->func = (unsigned long)tk->rp.kp.addr; 1536 entry->ret_ip = get_kretprobe_retaddr(ri); 1537 store_trace_args(&entry[1], &tk->tp, regs, ri->data, sizeof(*entry), dsize); 1538 1539 trace_event_buffer_commit(&fbuffer); 1540 } 1541 1542 static void 1543 kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, 1544 struct pt_regs *regs) 1545 { 1546 struct event_file_link *link; 1547 1548 trace_probe_for_each_link_rcu(link, &tk->tp) 1549 __kretprobe_trace_func(tk, ri, regs, link->file); 1550 } 1551 NOKPROBE_SYMBOL(kretprobe_trace_func); 1552 1553 /* Event entry printers */ 1554 static enum print_line_t 1555 print_kprobe_event(struct trace_iterator *iter, int flags, 1556 struct trace_event *event) 1557 { 1558 struct kprobe_trace_entry_head *field; 1559 struct trace_seq *s = &iter->seq; 1560 struct trace_probe *tp; 1561 1562 field = (struct kprobe_trace_entry_head *)iter->ent; 1563 tp = trace_probe_primary_from_call( 1564 container_of(event, struct trace_event_call, event)); 1565 if (WARN_ON_ONCE(!tp)) 1566 goto out; 1567 1568 trace_seq_printf(s, "%s: (", trace_probe_name(tp)); 1569 1570 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) 1571 goto out; 1572 1573 trace_seq_putc(s, ')'); 1574 1575 if (trace_probe_print_args(s, tp->args, tp->nr_args, 1576 (u8 *)&field[1], field) < 0) 1577 goto out; 1578 1579 trace_seq_putc(s, '\n'); 1580 out: 1581 return trace_handle_return(s); 1582 } 1583 1584 static enum print_line_t 1585 print_kretprobe_event(struct trace_iterator *iter, int flags, 1586 struct trace_event *event) 1587 { 1588 struct kretprobe_trace_entry_head *field; 1589 struct trace_seq *s = &iter->seq; 1590 struct trace_probe *tp; 1591 1592 field = (struct kretprobe_trace_entry_head *)iter->ent; 1593 tp = trace_probe_primary_from_call( 1594 container_of(event, struct trace_event_call, event)); 1595 if (WARN_ON_ONCE(!tp)) 1596 goto out; 1597 1598 trace_seq_printf(s, "%s: (", trace_probe_name(tp)); 1599 1600 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) 1601 goto out; 1602 1603 trace_seq_puts(s, " <- "); 1604 1605 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) 1606 goto out; 1607 1608 trace_seq_putc(s, ')'); 1609 1610 if (trace_probe_print_args(s, tp->args, tp->nr_args, 1611 (u8 *)&field[1], field) < 0) 1612 goto out; 1613 1614 trace_seq_putc(s, '\n'); 1615 1616 out: 1617 return trace_handle_return(s); 1618 } 1619 1620 1621 static int kprobe_event_define_fields(struct trace_event_call *event_call) 1622 { 1623 int ret; 1624 struct kprobe_trace_entry_head field; 1625 struct trace_probe *tp; 1626 1627 tp = trace_probe_primary_from_call(event_call); 1628 if (WARN_ON_ONCE(!tp)) 1629 return -ENOENT; 1630 1631 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); 1632 1633 return traceprobe_define_arg_fields(event_call, sizeof(field), tp); 1634 } 1635 1636 static int kretprobe_event_define_fields(struct trace_event_call *event_call) 1637 { 1638 int ret; 1639 struct kretprobe_trace_entry_head field; 1640 struct trace_probe *tp; 1641 1642 tp = trace_probe_primary_from_call(event_call); 1643 if (WARN_ON_ONCE(!tp)) 1644 return -ENOENT; 1645 1646 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); 1647 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); 1648 1649 return traceprobe_define_arg_fields(event_call, sizeof(field), tp); 1650 } 1651 1652 #ifdef CONFIG_PERF_EVENTS 1653 1654 /* Kprobe profile handler */ 1655 static int 1656 kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) 1657 { 1658 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1659 struct kprobe_trace_entry_head *entry; 1660 struct hlist_head *head; 1661 int size, __size, dsize; 1662 int rctx; 1663 1664 if (bpf_prog_array_valid(call)) { 1665 unsigned long orig_ip = instruction_pointer(regs); 1666 int ret; 1667 1668 ret = trace_call_bpf(call, regs); 1669 1670 /* 1671 * We need to check and see if we modified the pc of the 1672 * pt_regs, and if so return 1 so that we don't do the 1673 * single stepping. 1674 */ 1675 if (orig_ip != instruction_pointer(regs)) 1676 return 1; 1677 if (!ret) 1678 return 0; 1679 } 1680 1681 head = this_cpu_ptr(call->perf_events); 1682 if (hlist_empty(head)) 1683 return 0; 1684 1685 dsize = __get_data_size(&tk->tp, regs, NULL); 1686 __size = sizeof(*entry) + tk->tp.size + dsize; 1687 size = ALIGN(__size + sizeof(u32), sizeof(u64)); 1688 size -= sizeof(u32); 1689 1690 entry = perf_trace_buf_alloc(size, NULL, &rctx); 1691 if (!entry) 1692 return 0; 1693 1694 entry->ip = (unsigned long)tk->rp.kp.addr; 1695 memset(&entry[1], 0, dsize); 1696 store_trace_args(&entry[1], &tk->tp, regs, NULL, sizeof(*entry), dsize); 1697 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, 1698 head, NULL); 1699 return 0; 1700 } 1701 NOKPROBE_SYMBOL(kprobe_perf_func); 1702 1703 /* Kretprobe profile handler */ 1704 static void 1705 kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, 1706 struct pt_regs *regs) 1707 { 1708 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1709 struct kretprobe_trace_entry_head *entry; 1710 struct hlist_head *head; 1711 int size, __size, dsize; 1712 int rctx; 1713 1714 if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs)) 1715 return; 1716 1717 head = this_cpu_ptr(call->perf_events); 1718 if (hlist_empty(head)) 1719 return; 1720 1721 dsize = __get_data_size(&tk->tp, regs, ri->data); 1722 __size = sizeof(*entry) + tk->tp.size + dsize; 1723 size = ALIGN(__size + sizeof(u32), sizeof(u64)); 1724 size -= sizeof(u32); 1725 1726 entry = perf_trace_buf_alloc(size, NULL, &rctx); 1727 if (!entry) 1728 return; 1729 1730 entry->func = (unsigned long)tk->rp.kp.addr; 1731 entry->ret_ip = get_kretprobe_retaddr(ri); 1732 store_trace_args(&entry[1], &tk->tp, regs, ri->data, sizeof(*entry), dsize); 1733 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, 1734 head, NULL); 1735 } 1736 NOKPROBE_SYMBOL(kretprobe_perf_func); 1737 1738 int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type, 1739 const char **symbol, u64 *probe_offset, 1740 u64 *probe_addr, unsigned long *missed, 1741 bool perf_type_tracepoint) 1742 { 1743 const char *pevent = trace_event_name(event->tp_event); 1744 const char *group = event->tp_event->class->system; 1745 struct trace_kprobe *tk; 1746 1747 if (perf_type_tracepoint) 1748 tk = find_trace_kprobe(pevent, group); 1749 else 1750 tk = trace_kprobe_primary_from_call(event->tp_event); 1751 if (!tk) 1752 return -EINVAL; 1753 1754 *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE 1755 : BPF_FD_TYPE_KPROBE; 1756 *probe_offset = tk->rp.kp.offset; 1757 *probe_addr = kallsyms_show_value(current_cred()) ? 1758 (unsigned long)tk->rp.kp.addr : 0; 1759 *symbol = tk->symbol; 1760 if (missed) 1761 *missed = trace_kprobe_missed(tk); 1762 return 0; 1763 } 1764 #endif /* CONFIG_PERF_EVENTS */ 1765 1766 /* 1767 * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. 1768 * 1769 * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe 1770 * lockless, but we can't race with this __init function. 1771 */ 1772 static int kprobe_register(struct trace_event_call *event, 1773 enum trace_reg type, void *data) 1774 { 1775 struct trace_event_file *file = data; 1776 1777 switch (type) { 1778 case TRACE_REG_REGISTER: 1779 return enable_trace_kprobe(event, file); 1780 case TRACE_REG_UNREGISTER: 1781 return disable_trace_kprobe(event, file); 1782 1783 #ifdef CONFIG_PERF_EVENTS 1784 case TRACE_REG_PERF_REGISTER: 1785 return enable_trace_kprobe(event, NULL); 1786 case TRACE_REG_PERF_UNREGISTER: 1787 return disable_trace_kprobe(event, NULL); 1788 case TRACE_REG_PERF_OPEN: 1789 case TRACE_REG_PERF_CLOSE: 1790 case TRACE_REG_PERF_ADD: 1791 case TRACE_REG_PERF_DEL: 1792 return 0; 1793 #endif 1794 } 1795 return 0; 1796 } 1797 1798 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) 1799 { 1800 struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); 1801 int ret = 0; 1802 1803 raw_cpu_inc(*tk->nhit); 1804 1805 if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) 1806 kprobe_trace_func(tk, regs); 1807 #ifdef CONFIG_PERF_EVENTS 1808 if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) 1809 ret = kprobe_perf_func(tk, regs); 1810 #endif 1811 return ret; 1812 } 1813 NOKPROBE_SYMBOL(kprobe_dispatcher); 1814 1815 static int 1816 kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) 1817 { 1818 struct kretprobe *rp = get_kretprobe(ri); 1819 struct trace_kprobe *tk; 1820 1821 /* 1822 * There is a small chance that get_kretprobe(ri) returns NULL when 1823 * the kretprobe is unregister on another CPU between kretprobe's 1824 * trampoline_handler and this function. 1825 */ 1826 if (unlikely(!rp)) 1827 return 0; 1828 1829 tk = container_of(rp, struct trace_kprobe, rp); 1830 raw_cpu_inc(*tk->nhit); 1831 1832 if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) 1833 kretprobe_trace_func(tk, ri, regs); 1834 #ifdef CONFIG_PERF_EVENTS 1835 if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) 1836 kretprobe_perf_func(tk, ri, regs); 1837 #endif 1838 return 0; /* We don't tweak kernel, so just return 0 */ 1839 } 1840 NOKPROBE_SYMBOL(kretprobe_dispatcher); 1841 1842 static struct trace_event_functions kretprobe_funcs = { 1843 .trace = print_kretprobe_event 1844 }; 1845 1846 static struct trace_event_functions kprobe_funcs = { 1847 .trace = print_kprobe_event 1848 }; 1849 1850 static struct trace_event_fields kretprobe_fields_array[] = { 1851 { .type = TRACE_FUNCTION_TYPE, 1852 .define_fields = kretprobe_event_define_fields }, 1853 {} 1854 }; 1855 1856 static struct trace_event_fields kprobe_fields_array[] = { 1857 { .type = TRACE_FUNCTION_TYPE, 1858 .define_fields = kprobe_event_define_fields }, 1859 {} 1860 }; 1861 1862 static inline void init_trace_event_call(struct trace_kprobe *tk) 1863 { 1864 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1865 1866 if (trace_kprobe_is_return(tk)) { 1867 call->event.funcs = &kretprobe_funcs; 1868 call->class->fields_array = kretprobe_fields_array; 1869 } else { 1870 call->event.funcs = &kprobe_funcs; 1871 call->class->fields_array = kprobe_fields_array; 1872 } 1873 1874 call->flags = TRACE_EVENT_FL_KPROBE; 1875 call->class->reg = kprobe_register; 1876 } 1877 1878 static int register_kprobe_event(struct trace_kprobe *tk) 1879 { 1880 init_trace_event_call(tk); 1881 1882 return trace_probe_register_event_call(&tk->tp); 1883 } 1884 1885 static int unregister_kprobe_event(struct trace_kprobe *tk) 1886 { 1887 return trace_probe_unregister_event_call(&tk->tp); 1888 } 1889 1890 #ifdef CONFIG_PERF_EVENTS 1891 1892 /* create a trace_kprobe, but don't add it to global lists */ 1893 struct trace_event_call * 1894 create_local_trace_kprobe(char *func, void *addr, unsigned long offs, 1895 bool is_return) 1896 { 1897 enum probe_print_type ptype; 1898 struct trace_kprobe *tk __free(free_trace_kprobe) = NULL; 1899 int ret; 1900 char *event; 1901 1902 if (func) { 1903 ret = validate_probe_symbol(func); 1904 if (ret) 1905 return ERR_PTR(ret); 1906 } 1907 1908 /* 1909 * local trace_kprobes are not added to dyn_event, so they are never 1910 * searched in find_trace_kprobe(). Therefore, there is no concern of 1911 * duplicated name here. 1912 */ 1913 event = func ? func : "DUMMY_EVENT"; 1914 1915 tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func, 1916 offs, 0 /* maxactive */, 0 /* nargs */, 1917 is_return); 1918 1919 if (IS_ERR(tk)) { 1920 pr_info("Failed to allocate trace_probe.(%d)\n", 1921 (int)PTR_ERR(tk)); 1922 return ERR_CAST(tk); 1923 } 1924 1925 init_trace_event_call(tk); 1926 1927 ptype = trace_kprobe_is_return(tk) ? 1928 PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; 1929 if (traceprobe_set_print_fmt(&tk->tp, ptype) < 0) 1930 return ERR_PTR(-ENOMEM); 1931 1932 ret = __register_trace_kprobe(tk); 1933 if (ret < 0) 1934 return ERR_PTR(ret); 1935 1936 return trace_probe_event_call(&(no_free_ptr(tk)->tp)); 1937 } 1938 1939 void destroy_local_trace_kprobe(struct trace_event_call *event_call) 1940 { 1941 struct trace_kprobe *tk; 1942 1943 tk = trace_kprobe_primary_from_call(event_call); 1944 if (unlikely(!tk)) 1945 return; 1946 1947 if (trace_probe_is_enabled(&tk->tp)) { 1948 WARN_ON(1); 1949 return; 1950 } 1951 1952 __unregister_trace_kprobe(tk); 1953 1954 free_trace_kprobe(tk); 1955 } 1956 #endif /* CONFIG_PERF_EVENTS */ 1957 1958 static __init void enable_boot_kprobe_events(void) 1959 { 1960 struct trace_array *tr = top_trace_array(); 1961 struct trace_event_file *file; 1962 struct trace_kprobe *tk; 1963 struct dyn_event *pos; 1964 1965 guard(mutex)(&event_mutex); 1966 for_each_trace_kprobe(tk, pos) { 1967 list_for_each_entry(file, &tr->events, list) 1968 if (file->event_call == trace_probe_event_call(&tk->tp)) 1969 trace_event_enable_disable(file, 1, 0); 1970 } 1971 } 1972 1973 static __init void setup_boot_kprobe_events(void) 1974 { 1975 char *p, *cmd = kprobe_boot_events_buf; 1976 int ret; 1977 1978 strreplace(kprobe_boot_events_buf, ',', ' '); 1979 1980 while (cmd && *cmd != '\0') { 1981 p = strchr(cmd, ';'); 1982 if (p) 1983 *p++ = '\0'; 1984 1985 ret = create_or_delete_trace_kprobe(cmd); 1986 if (ret) 1987 pr_warn("Failed to add event(%d): %s\n", ret, cmd); 1988 1989 cmd = p; 1990 } 1991 1992 enable_boot_kprobe_events(); 1993 } 1994 1995 /* 1996 * Register dynevent at core_initcall. This allows kernel to setup kprobe 1997 * events in postcore_initcall without tracefs. 1998 */ 1999 static __init int init_kprobe_trace_early(void) 2000 { 2001 int ret; 2002 2003 ret = dyn_event_register(&trace_kprobe_ops); 2004 if (ret) 2005 return ret; 2006 2007 if (trace_kprobe_register_module_notifier()) 2008 return -EINVAL; 2009 2010 return 0; 2011 } 2012 core_initcall(init_kprobe_trace_early); 2013 2014 /* Make a tracefs interface for controlling probe points */ 2015 static __init int init_kprobe_trace(void) 2016 { 2017 int ret; 2018 2019 ret = tracing_init_dentry(); 2020 if (ret) 2021 return 0; 2022 2023 /* Event list interface */ 2024 trace_create_file("kprobe_events", TRACE_MODE_WRITE, 2025 NULL, NULL, &kprobe_events_ops); 2026 2027 /* Profile interface */ 2028 trace_create_file("kprobe_profile", TRACE_MODE_READ, 2029 NULL, NULL, &kprobe_profile_ops); 2030 2031 setup_boot_kprobe_events(); 2032 2033 return 0; 2034 } 2035 fs_initcall(init_kprobe_trace); 2036 2037 2038 #ifdef CONFIG_FTRACE_STARTUP_TEST 2039 static __init struct trace_event_file * 2040 find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) 2041 { 2042 struct trace_event_file *file; 2043 2044 list_for_each_entry(file, &tr->events, list) 2045 if (file->event_call == trace_probe_event_call(&tk->tp)) 2046 return file; 2047 2048 return NULL; 2049 } 2050 2051 /* 2052 * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this 2053 * stage, we can do this lockless. 2054 */ 2055 static __init int kprobe_trace_self_tests_init(void) 2056 { 2057 int ret, warn = 0; 2058 int (*target)(int, int, int, int, int, int); 2059 struct trace_kprobe *tk; 2060 struct trace_event_file *file; 2061 2062 if (tracing_is_disabled()) 2063 return -ENODEV; 2064 2065 if (tracing_selftest_disabled) 2066 return 0; 2067 2068 target = kprobe_trace_selftest_target; 2069 2070 pr_info("Testing kprobe tracing: "); 2071 2072 ret = create_or_delete_trace_kprobe("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)"); 2073 if (WARN_ONCE(ret, "error on probing function entry.")) { 2074 warn++; 2075 } else { 2076 /* Enable trace point */ 2077 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); 2078 if (WARN_ONCE(tk == NULL, "error on probing function entry.")) { 2079 warn++; 2080 } else { 2081 file = find_trace_probe_file(tk, top_trace_array()); 2082 if (WARN_ONCE(file == NULL, "error on getting probe file.")) { 2083 warn++; 2084 } else 2085 enable_trace_kprobe( 2086 trace_probe_event_call(&tk->tp), file); 2087 } 2088 } 2089 2090 ret = create_or_delete_trace_kprobe("r:testprobe2 kprobe_trace_selftest_target $retval"); 2091 if (WARN_ONCE(ret, "error on probing function return.")) { 2092 warn++; 2093 } else { 2094 /* Enable trace point */ 2095 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); 2096 if (WARN_ONCE(tk == NULL, "error on getting 2nd new probe.")) { 2097 warn++; 2098 } else { 2099 file = find_trace_probe_file(tk, top_trace_array()); 2100 if (WARN_ONCE(file == NULL, "error on getting probe file.")) { 2101 warn++; 2102 } else 2103 enable_trace_kprobe( 2104 trace_probe_event_call(&tk->tp), file); 2105 } 2106 } 2107 2108 if (warn) 2109 goto end; 2110 2111 ret = target(1, 2, 3, 4, 5, 6); 2112 2113 /* 2114 * Not expecting an error here, the check is only to prevent the 2115 * optimizer from removing the call to target() as otherwise there 2116 * are no side-effects and the call is never performed. 2117 */ 2118 if (ret != 21) 2119 warn++; 2120 2121 /* Disable trace points before removing it */ 2122 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); 2123 if (WARN_ONCE(tk == NULL, "error on getting test probe.")) { 2124 warn++; 2125 } else { 2126 if (WARN_ONCE(trace_kprobe_nhit(tk) != 1, 2127 "incorrect number of testprobe hits.")) 2128 warn++; 2129 2130 file = find_trace_probe_file(tk, top_trace_array()); 2131 if (WARN_ONCE(file == NULL, "error on getting probe file.")) { 2132 warn++; 2133 } else 2134 disable_trace_kprobe( 2135 trace_probe_event_call(&tk->tp), file); 2136 } 2137 2138 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); 2139 if (WARN_ONCE(tk == NULL, "error on getting 2nd test probe.")) { 2140 warn++; 2141 } else { 2142 if (WARN_ONCE(trace_kprobe_nhit(tk) != 1, 2143 "incorrect number of testprobe2 hits.")) 2144 warn++; 2145 2146 file = find_trace_probe_file(tk, top_trace_array()); 2147 if (WARN_ONCE(file == NULL, "error on getting probe file.")) { 2148 warn++; 2149 } else 2150 disable_trace_kprobe( 2151 trace_probe_event_call(&tk->tp), file); 2152 } 2153 2154 ret = create_or_delete_trace_kprobe("-:testprobe"); 2155 if (WARN_ONCE(ret, "error on deleting a probe.")) 2156 warn++; 2157 2158 ret = create_or_delete_trace_kprobe("-:testprobe2"); 2159 if (WARN_ONCE(ret, "error on deleting a probe.")) 2160 warn++; 2161 2162 2163 end: 2164 /* 2165 * Wait for the optimizer work to finish. Otherwise it might fiddle 2166 * with probes in already freed __init text. 2167 */ 2168 wait_for_kprobe_optimizer(); 2169 if (warn) 2170 pr_cont("NG: Some tests are failed. Please check them.\n"); 2171 else 2172 pr_cont("OK\n"); 2173 return 0; 2174 } 2175 2176 late_initcall(kprobe_trace_self_tests_init); 2177 2178 #endif 2179