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/security.h> 11 #include <linux/module.h> 12 #include <linux/uaccess.h> 13 #include <linux/rculist.h> 14 #include <linux/error-injection.h> 15 16 #include <asm/setup.h> /* for COMMAND_LINE_SIZE */ 17 18 #include "trace_dynevent.h" 19 #include "trace_kprobe_selftest.h" 20 #include "trace_probe.h" 21 #include "trace_probe_tmpl.h" 22 23 #define KPROBE_EVENT_SYSTEM "kprobes" 24 #define KRETPROBE_MAXACTIVE_MAX 4096 25 26 /* Kprobe early definition from command line */ 27 static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata; 28 29 static int __init set_kprobe_boot_events(char *str) 30 { 31 strlcpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE); 32 disable_tracing_selftest("running kprobe events"); 33 34 return 0; 35 } 36 __setup("kprobe_event=", set_kprobe_boot_events); 37 38 static int trace_kprobe_create(int argc, const char **argv); 39 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev); 40 static int trace_kprobe_release(struct dyn_event *ev); 41 static bool trace_kprobe_is_busy(struct dyn_event *ev); 42 static bool trace_kprobe_match(const char *system, const char *event, 43 int argc, const char **argv, struct dyn_event *ev); 44 45 static struct dyn_event_operations trace_kprobe_ops = { 46 .create = trace_kprobe_create, 47 .show = trace_kprobe_show, 48 .is_busy = trace_kprobe_is_busy, 49 .free = trace_kprobe_release, 50 .match = trace_kprobe_match, 51 }; 52 53 /* 54 * Kprobe event core functions 55 */ 56 struct trace_kprobe { 57 struct dyn_event devent; 58 struct kretprobe rp; /* Use rp.kp for kprobe use */ 59 unsigned long __percpu *nhit; 60 const char *symbol; /* symbol name */ 61 struct trace_probe tp; 62 }; 63 64 static bool is_trace_kprobe(struct dyn_event *ev) 65 { 66 return ev->ops == &trace_kprobe_ops; 67 } 68 69 static struct trace_kprobe *to_trace_kprobe(struct dyn_event *ev) 70 { 71 return container_of(ev, struct trace_kprobe, devent); 72 } 73 74 /** 75 * for_each_trace_kprobe - iterate over the trace_kprobe list 76 * @pos: the struct trace_kprobe * for each entry 77 * @dpos: the struct dyn_event * to use as a loop cursor 78 */ 79 #define for_each_trace_kprobe(pos, dpos) \ 80 for_each_dyn_event(dpos) \ 81 if (is_trace_kprobe(dpos) && (pos = to_trace_kprobe(dpos))) 82 83 #define SIZEOF_TRACE_KPROBE(n) \ 84 (offsetof(struct trace_kprobe, tp.args) + \ 85 (sizeof(struct probe_arg) * (n))) 86 87 static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk) 88 { 89 return tk->rp.handler != NULL; 90 } 91 92 static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk) 93 { 94 return tk->symbol ? tk->symbol : "unknown"; 95 } 96 97 static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk) 98 { 99 return tk->rp.kp.offset; 100 } 101 102 static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) 103 { 104 return !!(kprobe_gone(&tk->rp.kp)); 105 } 106 107 static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, 108 struct module *mod) 109 { 110 int len = strlen(module_name(mod)); 111 const char *name = trace_kprobe_symbol(tk); 112 113 return strncmp(module_name(mod), name, len) == 0 && name[len] == ':'; 114 } 115 116 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 mutex_lock(&module_mutex); 128 ret = !!find_module(tk->symbol); 129 mutex_unlock(&module_mutex); 130 *p = ':'; 131 132 return ret; 133 } 134 135 static bool trace_kprobe_is_busy(struct dyn_event *ev) 136 { 137 struct trace_kprobe *tk = to_trace_kprobe(ev); 138 139 return trace_probe_is_enabled(&tk->tp); 140 } 141 142 static bool trace_kprobe_match_command_head(struct trace_kprobe *tk, 143 int argc, const char **argv) 144 { 145 char buf[MAX_ARGSTR_LEN + 1]; 146 147 if (!argc) 148 return true; 149 150 if (!tk->symbol) 151 snprintf(buf, sizeof(buf), "0x%p", tk->rp.kp.addr); 152 else if (tk->rp.kp.offset) 153 snprintf(buf, sizeof(buf), "%s+%u", 154 trace_kprobe_symbol(tk), tk->rp.kp.offset); 155 else 156 snprintf(buf, sizeof(buf), "%s", trace_kprobe_symbol(tk)); 157 if (strcmp(buf, argv[0])) 158 return false; 159 argc--; argv++; 160 161 return trace_probe_match_command_args(&tk->tp, argc, argv); 162 } 163 164 static bool trace_kprobe_match(const char *system, const char *event, 165 int argc, const char **argv, struct dyn_event *ev) 166 { 167 struct trace_kprobe *tk = to_trace_kprobe(ev); 168 169 return strcmp(trace_probe_name(&tk->tp), event) == 0 && 170 (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) && 171 trace_kprobe_match_command_head(tk, argc, argv); 172 } 173 174 static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk) 175 { 176 unsigned long nhit = 0; 177 int cpu; 178 179 for_each_possible_cpu(cpu) 180 nhit += *per_cpu_ptr(tk->nhit, cpu); 181 182 return nhit; 183 } 184 185 static nokprobe_inline bool trace_kprobe_is_registered(struct trace_kprobe *tk) 186 { 187 return !(list_empty(&tk->rp.kp.list) && 188 hlist_unhashed(&tk->rp.kp.hlist)); 189 } 190 191 /* Return 0 if it fails to find the symbol address */ 192 static nokprobe_inline 193 unsigned long trace_kprobe_address(struct trace_kprobe *tk) 194 { 195 unsigned long addr; 196 197 if (tk->symbol) { 198 addr = (unsigned long) 199 kallsyms_lookup_name(trace_kprobe_symbol(tk)); 200 if (addr) 201 addr += tk->rp.kp.offset; 202 } else { 203 addr = (unsigned long)tk->rp.kp.addr; 204 } 205 return addr; 206 } 207 208 static nokprobe_inline struct trace_kprobe * 209 trace_kprobe_primary_from_call(struct trace_event_call *call) 210 { 211 struct trace_probe *tp; 212 213 tp = trace_probe_primary_from_call(call); 214 if (WARN_ON_ONCE(!tp)) 215 return NULL; 216 217 return container_of(tp, struct trace_kprobe, tp); 218 } 219 220 bool trace_kprobe_on_func_entry(struct trace_event_call *call) 221 { 222 struct trace_kprobe *tk = trace_kprobe_primary_from_call(call); 223 224 return tk ? kprobe_on_func_entry(tk->rp.kp.addr, 225 tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name, 226 tk->rp.kp.addr ? 0 : tk->rp.kp.offset) : false; 227 } 228 229 bool trace_kprobe_error_injectable(struct trace_event_call *call) 230 { 231 struct trace_kprobe *tk = trace_kprobe_primary_from_call(call); 232 233 return tk ? within_error_injection_list(trace_kprobe_address(tk)) : 234 false; 235 } 236 237 static int register_kprobe_event(struct trace_kprobe *tk); 238 static int unregister_kprobe_event(struct trace_kprobe *tk); 239 240 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); 241 static int kretprobe_dispatcher(struct kretprobe_instance *ri, 242 struct pt_regs *regs); 243 244 static void free_trace_kprobe(struct trace_kprobe *tk) 245 { 246 if (tk) { 247 trace_probe_cleanup(&tk->tp); 248 kfree(tk->symbol); 249 free_percpu(tk->nhit); 250 kfree(tk); 251 } 252 } 253 254 /* 255 * Allocate new trace_probe and initialize it (including kprobes). 256 */ 257 static struct trace_kprobe *alloc_trace_kprobe(const char *group, 258 const char *event, 259 void *addr, 260 const char *symbol, 261 unsigned long offs, 262 int maxactive, 263 int nargs, bool is_return) 264 { 265 struct trace_kprobe *tk; 266 int ret = -ENOMEM; 267 268 tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL); 269 if (!tk) 270 return ERR_PTR(ret); 271 272 tk->nhit = alloc_percpu(unsigned long); 273 if (!tk->nhit) 274 goto error; 275 276 if (symbol) { 277 tk->symbol = kstrdup(symbol, GFP_KERNEL); 278 if (!tk->symbol) 279 goto error; 280 tk->rp.kp.symbol_name = tk->symbol; 281 tk->rp.kp.offset = offs; 282 } else 283 tk->rp.kp.addr = addr; 284 285 if (is_return) 286 tk->rp.handler = kretprobe_dispatcher; 287 else 288 tk->rp.kp.pre_handler = kprobe_dispatcher; 289 290 tk->rp.maxactive = maxactive; 291 INIT_HLIST_NODE(&tk->rp.kp.hlist); 292 INIT_LIST_HEAD(&tk->rp.kp.list); 293 294 ret = trace_probe_init(&tk->tp, event, group, false); 295 if (ret < 0) 296 goto error; 297 298 dyn_event_init(&tk->devent, &trace_kprobe_ops); 299 return tk; 300 error: 301 free_trace_kprobe(tk); 302 return ERR_PTR(ret); 303 } 304 305 static struct trace_kprobe *find_trace_kprobe(const char *event, 306 const char *group) 307 { 308 struct dyn_event *pos; 309 struct trace_kprobe *tk; 310 311 for_each_trace_kprobe(tk, pos) 312 if (strcmp(trace_probe_name(&tk->tp), event) == 0 && 313 strcmp(trace_probe_group_name(&tk->tp), group) == 0) 314 return tk; 315 return NULL; 316 } 317 318 static inline int __enable_trace_kprobe(struct trace_kprobe *tk) 319 { 320 int ret = 0; 321 322 if (trace_kprobe_is_registered(tk) && !trace_kprobe_has_gone(tk)) { 323 if (trace_kprobe_is_return(tk)) 324 ret = enable_kretprobe(&tk->rp); 325 else 326 ret = enable_kprobe(&tk->rp.kp); 327 } 328 329 return ret; 330 } 331 332 static void __disable_trace_kprobe(struct trace_probe *tp) 333 { 334 struct trace_probe *pos; 335 struct trace_kprobe *tk; 336 337 list_for_each_entry(pos, trace_probe_probe_list(tp), list) { 338 tk = container_of(pos, struct trace_kprobe, tp); 339 if (!trace_kprobe_is_registered(tk)) 340 continue; 341 if (trace_kprobe_is_return(tk)) 342 disable_kretprobe(&tk->rp); 343 else 344 disable_kprobe(&tk->rp.kp); 345 } 346 } 347 348 /* 349 * Enable trace_probe 350 * if the file is NULL, enable "perf" handler, or enable "trace" handler. 351 */ 352 static int enable_trace_kprobe(struct trace_event_call *call, 353 struct trace_event_file *file) 354 { 355 struct trace_probe *pos, *tp; 356 struct trace_kprobe *tk; 357 bool enabled; 358 int ret = 0; 359 360 tp = trace_probe_primary_from_call(call); 361 if (WARN_ON_ONCE(!tp)) 362 return -ENODEV; 363 enabled = trace_probe_is_enabled(tp); 364 365 /* This also changes "enabled" state */ 366 if (file) { 367 ret = trace_probe_add_file(tp, file); 368 if (ret) 369 return ret; 370 } else 371 trace_probe_set_flag(tp, TP_FLAG_PROFILE); 372 373 if (enabled) 374 return 0; 375 376 list_for_each_entry(pos, trace_probe_probe_list(tp), list) { 377 tk = container_of(pos, struct trace_kprobe, tp); 378 if (trace_kprobe_has_gone(tk)) 379 continue; 380 ret = __enable_trace_kprobe(tk); 381 if (ret) 382 break; 383 enabled = true; 384 } 385 386 if (ret) { 387 /* Failed to enable one of them. Roll back all */ 388 if (enabled) 389 __disable_trace_kprobe(tp); 390 if (file) 391 trace_probe_remove_file(tp, file); 392 else 393 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 394 } 395 396 return ret; 397 } 398 399 /* 400 * Disable trace_probe 401 * if the file is NULL, disable "perf" handler, or disable "trace" handler. 402 */ 403 static int disable_trace_kprobe(struct trace_event_call *call, 404 struct trace_event_file *file) 405 { 406 struct trace_probe *tp; 407 408 tp = trace_probe_primary_from_call(call); 409 if (WARN_ON_ONCE(!tp)) 410 return -ENODEV; 411 412 if (file) { 413 if (!trace_probe_get_file_link(tp, file)) 414 return -ENOENT; 415 if (!trace_probe_has_single_file(tp)) 416 goto out; 417 trace_probe_clear_flag(tp, TP_FLAG_TRACE); 418 } else 419 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 420 421 if (!trace_probe_is_enabled(tp)) 422 __disable_trace_kprobe(tp); 423 424 out: 425 if (file) 426 /* 427 * Synchronization is done in below function. For perf event, 428 * file == NULL and perf_trace_event_unreg() calls 429 * tracepoint_synchronize_unregister() to ensure synchronize 430 * event. We don't need to care about it. 431 */ 432 trace_probe_remove_file(tp, file); 433 434 return 0; 435 } 436 437 #if defined(CONFIG_DYNAMIC_FTRACE) && \ 438 !defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE) 439 static bool __within_notrace_func(unsigned long addr) 440 { 441 unsigned long offset, size; 442 443 if (!addr || !kallsyms_lookup_size_offset(addr, &size, &offset)) 444 return false; 445 446 /* Get the entry address of the target function */ 447 addr -= offset; 448 449 /* 450 * Since ftrace_location_range() does inclusive range check, we need 451 * to subtract 1 byte from the end address. 452 */ 453 return !ftrace_location_range(addr, addr + size - 1); 454 } 455 456 static bool within_notrace_func(struct trace_kprobe *tk) 457 { 458 unsigned long addr = trace_kprobe_address(tk); 459 char symname[KSYM_NAME_LEN], *p; 460 461 if (!__within_notrace_func(addr)) 462 return false; 463 464 /* Check if the address is on a suffixed-symbol */ 465 if (!lookup_symbol_name(addr, symname)) { 466 p = strchr(symname, '.'); 467 if (!p) 468 return true; 469 *p = '\0'; 470 addr = (unsigned long)kprobe_lookup_name(symname, 0); 471 if (addr) 472 return __within_notrace_func(addr); 473 } 474 475 return true; 476 } 477 #else 478 #define within_notrace_func(tk) (false) 479 #endif 480 481 /* Internal register function - just handle k*probes and flags */ 482 static int __register_trace_kprobe(struct trace_kprobe *tk) 483 { 484 int i, ret; 485 486 ret = security_locked_down(LOCKDOWN_KPROBES); 487 if (ret) 488 return ret; 489 490 if (trace_kprobe_is_registered(tk)) 491 return -EINVAL; 492 493 if (within_notrace_func(tk)) { 494 pr_warn("Could not probe notrace function %s\n", 495 trace_kprobe_symbol(tk)); 496 return -EINVAL; 497 } 498 499 for (i = 0; i < tk->tp.nr_args; i++) { 500 ret = traceprobe_update_arg(&tk->tp.args[i]); 501 if (ret) 502 return ret; 503 } 504 505 /* Set/clear disabled flag according to tp->flag */ 506 if (trace_probe_is_enabled(&tk->tp)) 507 tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; 508 else 509 tk->rp.kp.flags |= KPROBE_FLAG_DISABLED; 510 511 if (trace_kprobe_is_return(tk)) 512 ret = register_kretprobe(&tk->rp); 513 else 514 ret = register_kprobe(&tk->rp.kp); 515 516 return ret; 517 } 518 519 /* Internal unregister function - just handle k*probes and flags */ 520 static void __unregister_trace_kprobe(struct trace_kprobe *tk) 521 { 522 if (trace_kprobe_is_registered(tk)) { 523 if (trace_kprobe_is_return(tk)) 524 unregister_kretprobe(&tk->rp); 525 else 526 unregister_kprobe(&tk->rp.kp); 527 /* Cleanup kprobe for reuse and mark it unregistered */ 528 INIT_HLIST_NODE(&tk->rp.kp.hlist); 529 INIT_LIST_HEAD(&tk->rp.kp.list); 530 if (tk->rp.kp.symbol_name) 531 tk->rp.kp.addr = NULL; 532 } 533 } 534 535 /* Unregister a trace_probe and probe_event */ 536 static int unregister_trace_kprobe(struct trace_kprobe *tk) 537 { 538 /* If other probes are on the event, just unregister kprobe */ 539 if (trace_probe_has_sibling(&tk->tp)) 540 goto unreg; 541 542 /* Enabled event can not be unregistered */ 543 if (trace_probe_is_enabled(&tk->tp)) 544 return -EBUSY; 545 546 /* Will fail if probe is being used by ftrace or perf */ 547 if (unregister_kprobe_event(tk)) 548 return -EBUSY; 549 550 unreg: 551 __unregister_trace_kprobe(tk); 552 dyn_event_remove(&tk->devent); 553 trace_probe_unlink(&tk->tp); 554 555 return 0; 556 } 557 558 static bool trace_kprobe_has_same_kprobe(struct trace_kprobe *orig, 559 struct trace_kprobe *comp) 560 { 561 struct trace_probe_event *tpe = orig->tp.event; 562 struct trace_probe *pos; 563 int i; 564 565 list_for_each_entry(pos, &tpe->probes, list) { 566 orig = container_of(pos, struct trace_kprobe, tp); 567 if (strcmp(trace_kprobe_symbol(orig), 568 trace_kprobe_symbol(comp)) || 569 trace_kprobe_offset(orig) != trace_kprobe_offset(comp)) 570 continue; 571 572 /* 573 * trace_probe_compare_arg_type() ensured that nr_args and 574 * each argument name and type are same. Let's compare comm. 575 */ 576 for (i = 0; i < orig->tp.nr_args; i++) { 577 if (strcmp(orig->tp.args[i].comm, 578 comp->tp.args[i].comm)) 579 break; 580 } 581 582 if (i == orig->tp.nr_args) 583 return true; 584 } 585 586 return false; 587 } 588 589 static int append_trace_kprobe(struct trace_kprobe *tk, struct trace_kprobe *to) 590 { 591 int ret; 592 593 ret = trace_probe_compare_arg_type(&tk->tp, &to->tp); 594 if (ret) { 595 /* Note that argument starts index = 2 */ 596 trace_probe_log_set_index(ret + 1); 597 trace_probe_log_err(0, DIFF_ARG_TYPE); 598 return -EEXIST; 599 } 600 if (trace_kprobe_has_same_kprobe(to, tk)) { 601 trace_probe_log_set_index(0); 602 trace_probe_log_err(0, SAME_PROBE); 603 return -EEXIST; 604 } 605 606 /* Append to existing event */ 607 ret = trace_probe_append(&tk->tp, &to->tp); 608 if (ret) 609 return ret; 610 611 /* Register k*probe */ 612 ret = __register_trace_kprobe(tk); 613 if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) { 614 pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); 615 ret = 0; 616 } 617 618 if (ret) 619 trace_probe_unlink(&tk->tp); 620 else 621 dyn_event_add(&tk->devent); 622 623 return ret; 624 } 625 626 /* Register a trace_probe and probe_event */ 627 static int register_trace_kprobe(struct trace_kprobe *tk) 628 { 629 struct trace_kprobe *old_tk; 630 int ret; 631 632 mutex_lock(&event_mutex); 633 634 old_tk = find_trace_kprobe(trace_probe_name(&tk->tp), 635 trace_probe_group_name(&tk->tp)); 636 if (old_tk) { 637 if (trace_kprobe_is_return(tk) != trace_kprobe_is_return(old_tk)) { 638 trace_probe_log_set_index(0); 639 trace_probe_log_err(0, DIFF_PROBE_TYPE); 640 ret = -EEXIST; 641 } else { 642 ret = append_trace_kprobe(tk, old_tk); 643 } 644 goto end; 645 } 646 647 /* Register new event */ 648 ret = register_kprobe_event(tk); 649 if (ret) { 650 pr_warn("Failed to register probe event(%d)\n", ret); 651 goto end; 652 } 653 654 /* Register k*probe */ 655 ret = __register_trace_kprobe(tk); 656 if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) { 657 pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); 658 ret = 0; 659 } 660 661 if (ret < 0) 662 unregister_kprobe_event(tk); 663 else 664 dyn_event_add(&tk->devent); 665 666 end: 667 mutex_unlock(&event_mutex); 668 return ret; 669 } 670 671 /* Module notifier call back, checking event on the module */ 672 static int trace_kprobe_module_callback(struct notifier_block *nb, 673 unsigned long val, void *data) 674 { 675 struct module *mod = data; 676 struct dyn_event *pos; 677 struct trace_kprobe *tk; 678 int ret; 679 680 if (val != MODULE_STATE_COMING) 681 return NOTIFY_DONE; 682 683 /* Update probes on coming module */ 684 mutex_lock(&event_mutex); 685 for_each_trace_kprobe(tk, pos) { 686 if (trace_kprobe_within_module(tk, mod)) { 687 /* Don't need to check busy - this should have gone. */ 688 __unregister_trace_kprobe(tk); 689 ret = __register_trace_kprobe(tk); 690 if (ret) 691 pr_warn("Failed to re-register probe %s on %s: %d\n", 692 trace_probe_name(&tk->tp), 693 module_name(mod), ret); 694 } 695 } 696 mutex_unlock(&event_mutex); 697 698 return NOTIFY_DONE; 699 } 700 701 static struct notifier_block trace_kprobe_module_nb = { 702 .notifier_call = trace_kprobe_module_callback, 703 .priority = 1 /* Invoked after kprobe module callback */ 704 }; 705 706 /* Convert certain expected symbols into '_' when generating event names */ 707 static inline void sanitize_event_name(char *name) 708 { 709 while (*name++ != '\0') 710 if (*name == ':' || *name == '.') 711 *name = '_'; 712 } 713 714 static int trace_kprobe_create(int argc, const char *argv[]) 715 { 716 /* 717 * Argument syntax: 718 * - Add kprobe: 719 * p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] 720 * - Add kretprobe: 721 * r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS] 722 * Or 723 * p:[GRP/]EVENT] [MOD:]KSYM[+0]%return [FETCHARGS] 724 * 725 * Fetch args: 726 * $retval : fetch return value 727 * $stack : fetch stack address 728 * $stackN : fetch Nth of stack (N:0-) 729 * $comm : fetch current task comm 730 * @ADDR : fetch memory at ADDR (ADDR should be in kernel) 731 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) 732 * %REG : fetch register REG 733 * Dereferencing memory fetch: 734 * +|-offs(ARG) : fetch memory at ARG +|- offs address. 735 * Alias name of args: 736 * NAME=FETCHARG : set NAME as alias of FETCHARG. 737 * Type of args: 738 * FETCHARG:TYPE : use TYPE instead of unsigned long. 739 */ 740 struct trace_kprobe *tk = NULL; 741 int i, len, ret = 0; 742 bool is_return = false; 743 char *symbol = NULL, *tmp = NULL; 744 const char *event = NULL, *group = KPROBE_EVENT_SYSTEM; 745 int maxactive = 0; 746 long offset = 0; 747 void *addr = NULL; 748 char buf[MAX_EVENT_NAME_LEN]; 749 unsigned int flags = TPARG_FL_KERNEL; 750 751 switch (argv[0][0]) { 752 case 'r': 753 is_return = true; 754 break; 755 case 'p': 756 break; 757 default: 758 return -ECANCELED; 759 } 760 if (argc < 2) 761 return -ECANCELED; 762 763 trace_probe_log_init("trace_kprobe", argc, argv); 764 765 event = strchr(&argv[0][1], ':'); 766 if (event) 767 event++; 768 769 if (isdigit(argv[0][1])) { 770 if (!is_return) { 771 trace_probe_log_err(1, MAXACT_NO_KPROBE); 772 goto parse_error; 773 } 774 if (event) 775 len = event - &argv[0][1] - 1; 776 else 777 len = strlen(&argv[0][1]); 778 if (len > MAX_EVENT_NAME_LEN - 1) { 779 trace_probe_log_err(1, BAD_MAXACT); 780 goto parse_error; 781 } 782 memcpy(buf, &argv[0][1], len); 783 buf[len] = '\0'; 784 ret = kstrtouint(buf, 0, &maxactive); 785 if (ret || !maxactive) { 786 trace_probe_log_err(1, BAD_MAXACT); 787 goto parse_error; 788 } 789 /* kretprobes instances are iterated over via a list. The 790 * maximum should stay reasonable. 791 */ 792 if (maxactive > KRETPROBE_MAXACTIVE_MAX) { 793 trace_probe_log_err(1, MAXACT_TOO_BIG); 794 goto parse_error; 795 } 796 } 797 798 /* try to parse an address. if that fails, try to read the 799 * input as a symbol. */ 800 if (kstrtoul(argv[1], 0, (unsigned long *)&addr)) { 801 trace_probe_log_set_index(1); 802 /* Check whether uprobe event specified */ 803 if (strchr(argv[1], '/') && strchr(argv[1], ':')) { 804 ret = -ECANCELED; 805 goto error; 806 } 807 /* a symbol specified */ 808 symbol = kstrdup(argv[1], GFP_KERNEL); 809 if (!symbol) 810 return -ENOMEM; 811 812 tmp = strchr(symbol, '%'); 813 if (tmp) { 814 if (!strcmp(tmp, "%return")) { 815 *tmp = '\0'; 816 is_return = true; 817 } else { 818 trace_probe_log_err(tmp - symbol, BAD_ADDR_SUFFIX); 819 goto parse_error; 820 } 821 } 822 823 /* TODO: support .init module functions */ 824 ret = traceprobe_split_symbol_offset(symbol, &offset); 825 if (ret || offset < 0 || offset > UINT_MAX) { 826 trace_probe_log_err(0, BAD_PROBE_ADDR); 827 goto parse_error; 828 } 829 if (is_return) 830 flags |= TPARG_FL_RETURN; 831 if (kprobe_on_func_entry(NULL, symbol, offset)) 832 flags |= TPARG_FL_FENTRY; 833 if (offset && is_return && !(flags & TPARG_FL_FENTRY)) { 834 trace_probe_log_err(0, BAD_RETPROBE); 835 goto parse_error; 836 } 837 } 838 839 trace_probe_log_set_index(0); 840 if (event) { 841 ret = traceprobe_parse_event_name(&event, &group, buf, 842 event - argv[0]); 843 if (ret) 844 goto parse_error; 845 } else { 846 /* Make a new event name */ 847 if (symbol) 848 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", 849 is_return ? 'r' : 'p', symbol, offset); 850 else 851 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", 852 is_return ? 'r' : 'p', addr); 853 sanitize_event_name(buf); 854 event = buf; 855 } 856 857 /* setup a probe */ 858 tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive, 859 argc - 2, is_return); 860 if (IS_ERR(tk)) { 861 ret = PTR_ERR(tk); 862 /* This must return -ENOMEM, else there is a bug */ 863 WARN_ON_ONCE(ret != -ENOMEM); 864 goto out; /* We know tk is not allocated */ 865 } 866 argc -= 2; argv += 2; 867 868 /* parse arguments */ 869 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { 870 tmp = kstrdup(argv[i], GFP_KERNEL); 871 if (!tmp) { 872 ret = -ENOMEM; 873 goto error; 874 } 875 876 trace_probe_log_set_index(i + 2); 877 ret = traceprobe_parse_probe_arg(&tk->tp, i, tmp, flags); 878 kfree(tmp); 879 if (ret) 880 goto error; /* This can be -ENOMEM */ 881 } 882 883 ret = traceprobe_set_print_fmt(&tk->tp, is_return); 884 if (ret < 0) 885 goto error; 886 887 ret = register_trace_kprobe(tk); 888 if (ret) { 889 trace_probe_log_set_index(1); 890 if (ret == -EILSEQ) 891 trace_probe_log_err(0, BAD_INSN_BNDRY); 892 else if (ret == -ENOENT) 893 trace_probe_log_err(0, BAD_PROBE_ADDR); 894 else if (ret != -ENOMEM && ret != -EEXIST) 895 trace_probe_log_err(0, FAIL_REG_PROBE); 896 goto error; 897 } 898 899 out: 900 trace_probe_log_clear(); 901 kfree(symbol); 902 return ret; 903 904 parse_error: 905 ret = -EINVAL; 906 error: 907 free_trace_kprobe(tk); 908 goto out; 909 } 910 911 static int create_or_delete_trace_kprobe(int argc, char **argv) 912 { 913 int ret; 914 915 if (argv[0][0] == '-') 916 return dyn_event_release(argc, argv, &trace_kprobe_ops); 917 918 ret = trace_kprobe_create(argc, (const char **)argv); 919 return ret == -ECANCELED ? -EINVAL : ret; 920 } 921 922 static int trace_kprobe_run_command(struct dynevent_cmd *cmd) 923 { 924 return trace_run_command(cmd->seq.buffer, create_or_delete_trace_kprobe); 925 } 926 927 /** 928 * kprobe_event_cmd_init - Initialize a kprobe event command object 929 * @cmd: A pointer to the dynevent_cmd struct representing the new event 930 * @buf: A pointer to the buffer used to build the command 931 * @maxlen: The length of the buffer passed in @buf 932 * 933 * Initialize a synthetic event command object. Use this before 934 * calling any of the other kprobe_event functions. 935 */ 936 void kprobe_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen) 937 { 938 dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_KPROBE, 939 trace_kprobe_run_command); 940 } 941 EXPORT_SYMBOL_GPL(kprobe_event_cmd_init); 942 943 /** 944 * __kprobe_event_gen_cmd_start - Generate a kprobe event command from arg list 945 * @cmd: A pointer to the dynevent_cmd struct representing the new event 946 * @name: The name of the kprobe event 947 * @loc: The location of the kprobe event 948 * @kretprobe: Is this a return probe? 949 * @args: Variable number of arg (pairs), one pair for each field 950 * 951 * NOTE: Users normally won't want to call this function directly, but 952 * rather use the kprobe_event_gen_cmd_start() wrapper, which automatically 953 * adds a NULL to the end of the arg list. If this function is used 954 * directly, make sure the last arg in the variable arg list is NULL. 955 * 956 * Generate a kprobe event command to be executed by 957 * kprobe_event_gen_cmd_end(). This function can be used to generate the 958 * complete command or only the first part of it; in the latter case, 959 * kprobe_event_add_fields() can be used to add more fields following this. 960 * 961 * Unlikely the synth_event_gen_cmd_start(), @loc must be specified. This 962 * returns -EINVAL if @loc == NULL. 963 * 964 * Return: 0 if successful, error otherwise. 965 */ 966 int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe, 967 const char *name, const char *loc, ...) 968 { 969 char buf[MAX_EVENT_NAME_LEN]; 970 struct dynevent_arg arg; 971 va_list args; 972 int ret; 973 974 if (cmd->type != DYNEVENT_TYPE_KPROBE) 975 return -EINVAL; 976 977 if (!loc) 978 return -EINVAL; 979 980 if (kretprobe) 981 snprintf(buf, MAX_EVENT_NAME_LEN, "r:kprobes/%s", name); 982 else 983 snprintf(buf, MAX_EVENT_NAME_LEN, "p:kprobes/%s", name); 984 985 ret = dynevent_str_add(cmd, buf); 986 if (ret) 987 return ret; 988 989 dynevent_arg_init(&arg, 0); 990 arg.str = loc; 991 ret = dynevent_arg_add(cmd, &arg, NULL); 992 if (ret) 993 return ret; 994 995 va_start(args, loc); 996 for (;;) { 997 const char *field; 998 999 field = va_arg(args, const char *); 1000 if (!field) 1001 break; 1002 1003 if (++cmd->n_fields > MAX_TRACE_ARGS) { 1004 ret = -EINVAL; 1005 break; 1006 } 1007 1008 arg.str = field; 1009 ret = dynevent_arg_add(cmd, &arg, NULL); 1010 if (ret) 1011 break; 1012 } 1013 va_end(args); 1014 1015 return ret; 1016 } 1017 EXPORT_SYMBOL_GPL(__kprobe_event_gen_cmd_start); 1018 1019 /** 1020 * __kprobe_event_add_fields - Add probe fields to a kprobe command from arg list 1021 * @cmd: A pointer to the dynevent_cmd struct representing the new event 1022 * @args: Variable number of arg (pairs), one pair for each field 1023 * 1024 * NOTE: Users normally won't want to call this function directly, but 1025 * rather use the kprobe_event_add_fields() wrapper, which 1026 * automatically adds a NULL to the end of the arg list. If this 1027 * function is used directly, make sure the last arg in the variable 1028 * arg list is NULL. 1029 * 1030 * Add probe fields to an existing kprobe command using a variable 1031 * list of args. Fields are added in the same order they're listed. 1032 * 1033 * Return: 0 if successful, error otherwise. 1034 */ 1035 int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...) 1036 { 1037 struct dynevent_arg arg; 1038 va_list args; 1039 int ret = 0; 1040 1041 if (cmd->type != DYNEVENT_TYPE_KPROBE) 1042 return -EINVAL; 1043 1044 dynevent_arg_init(&arg, 0); 1045 1046 va_start(args, cmd); 1047 for (;;) { 1048 const char *field; 1049 1050 field = va_arg(args, const char *); 1051 if (!field) 1052 break; 1053 1054 if (++cmd->n_fields > MAX_TRACE_ARGS) { 1055 ret = -EINVAL; 1056 break; 1057 } 1058 1059 arg.str = field; 1060 ret = dynevent_arg_add(cmd, &arg, NULL); 1061 if (ret) 1062 break; 1063 } 1064 va_end(args); 1065 1066 return ret; 1067 } 1068 EXPORT_SYMBOL_GPL(__kprobe_event_add_fields); 1069 1070 /** 1071 * kprobe_event_delete - Delete a kprobe event 1072 * @name: The name of the kprobe event to delete 1073 * 1074 * Delete a kprobe event with the give @name from kernel code rather 1075 * than directly from the command line. 1076 * 1077 * Return: 0 if successful, error otherwise. 1078 */ 1079 int kprobe_event_delete(const char *name) 1080 { 1081 char buf[MAX_EVENT_NAME_LEN]; 1082 1083 snprintf(buf, MAX_EVENT_NAME_LEN, "-:%s", name); 1084 1085 return trace_run_command(buf, create_or_delete_trace_kprobe); 1086 } 1087 EXPORT_SYMBOL_GPL(kprobe_event_delete); 1088 1089 static int trace_kprobe_release(struct dyn_event *ev) 1090 { 1091 struct trace_kprobe *tk = to_trace_kprobe(ev); 1092 int ret = unregister_trace_kprobe(tk); 1093 1094 if (!ret) 1095 free_trace_kprobe(tk); 1096 return ret; 1097 } 1098 1099 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev) 1100 { 1101 struct trace_kprobe *tk = to_trace_kprobe(ev); 1102 int i; 1103 1104 seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p'); 1105 if (trace_kprobe_is_return(tk) && tk->rp.maxactive) 1106 seq_printf(m, "%d", tk->rp.maxactive); 1107 seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp), 1108 trace_probe_name(&tk->tp)); 1109 1110 if (!tk->symbol) 1111 seq_printf(m, " 0x%p", tk->rp.kp.addr); 1112 else if (tk->rp.kp.offset) 1113 seq_printf(m, " %s+%u", trace_kprobe_symbol(tk), 1114 tk->rp.kp.offset); 1115 else 1116 seq_printf(m, " %s", trace_kprobe_symbol(tk)); 1117 1118 for (i = 0; i < tk->tp.nr_args; i++) 1119 seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm); 1120 seq_putc(m, '\n'); 1121 1122 return 0; 1123 } 1124 1125 static int probes_seq_show(struct seq_file *m, void *v) 1126 { 1127 struct dyn_event *ev = v; 1128 1129 if (!is_trace_kprobe(ev)) 1130 return 0; 1131 1132 return trace_kprobe_show(m, ev); 1133 } 1134 1135 static const struct seq_operations probes_seq_op = { 1136 .start = dyn_event_seq_start, 1137 .next = dyn_event_seq_next, 1138 .stop = dyn_event_seq_stop, 1139 .show = probes_seq_show 1140 }; 1141 1142 static int probes_open(struct inode *inode, struct file *file) 1143 { 1144 int ret; 1145 1146 ret = security_locked_down(LOCKDOWN_TRACEFS); 1147 if (ret) 1148 return ret; 1149 1150 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { 1151 ret = dyn_events_release_all(&trace_kprobe_ops); 1152 if (ret < 0) 1153 return ret; 1154 } 1155 1156 return seq_open(file, &probes_seq_op); 1157 } 1158 1159 static ssize_t probes_write(struct file *file, const char __user *buffer, 1160 size_t count, loff_t *ppos) 1161 { 1162 return trace_parse_run_command(file, buffer, count, ppos, 1163 create_or_delete_trace_kprobe); 1164 } 1165 1166 static const struct file_operations kprobe_events_ops = { 1167 .owner = THIS_MODULE, 1168 .open = probes_open, 1169 .read = seq_read, 1170 .llseek = seq_lseek, 1171 .release = seq_release, 1172 .write = probes_write, 1173 }; 1174 1175 /* Probes profiling interfaces */ 1176 static int probes_profile_seq_show(struct seq_file *m, void *v) 1177 { 1178 struct dyn_event *ev = v; 1179 struct trace_kprobe *tk; 1180 1181 if (!is_trace_kprobe(ev)) 1182 return 0; 1183 1184 tk = to_trace_kprobe(ev); 1185 seq_printf(m, " %-44s %15lu %15lu\n", 1186 trace_probe_name(&tk->tp), 1187 trace_kprobe_nhit(tk), 1188 tk->rp.kp.nmissed); 1189 1190 return 0; 1191 } 1192 1193 static const struct seq_operations profile_seq_op = { 1194 .start = dyn_event_seq_start, 1195 .next = dyn_event_seq_next, 1196 .stop = dyn_event_seq_stop, 1197 .show = probes_profile_seq_show 1198 }; 1199 1200 static int profile_open(struct inode *inode, struct file *file) 1201 { 1202 int ret; 1203 1204 ret = security_locked_down(LOCKDOWN_TRACEFS); 1205 if (ret) 1206 return ret; 1207 1208 return seq_open(file, &profile_seq_op); 1209 } 1210 1211 static const struct file_operations kprobe_profile_ops = { 1212 .owner = THIS_MODULE, 1213 .open = profile_open, 1214 .read = seq_read, 1215 .llseek = seq_lseek, 1216 .release = seq_release, 1217 }; 1218 1219 /* Kprobe specific fetch functions */ 1220 1221 /* Return the length of string -- including null terminal byte */ 1222 static nokprobe_inline int 1223 fetch_store_strlen_user(unsigned long addr) 1224 { 1225 const void __user *uaddr = (__force const void __user *)addr; 1226 1227 return strnlen_user_nofault(uaddr, MAX_STRING_SIZE); 1228 } 1229 1230 /* Return the length of string -- including null terminal byte */ 1231 static nokprobe_inline int 1232 fetch_store_strlen(unsigned long addr) 1233 { 1234 int ret, len = 0; 1235 u8 c; 1236 1237 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1238 if (addr < TASK_SIZE) 1239 return fetch_store_strlen_user(addr); 1240 #endif 1241 1242 do { 1243 ret = copy_from_kernel_nofault(&c, (u8 *)addr + len, 1); 1244 len++; 1245 } while (c && ret == 0 && len < MAX_STRING_SIZE); 1246 1247 return (ret < 0) ? ret : len; 1248 } 1249 1250 /* 1251 * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf 1252 * with max length and relative data location. 1253 */ 1254 static nokprobe_inline int 1255 fetch_store_string_user(unsigned long addr, void *dest, void *base) 1256 { 1257 const void __user *uaddr = (__force const void __user *)addr; 1258 int maxlen = get_loc_len(*(u32 *)dest); 1259 void *__dest; 1260 long ret; 1261 1262 if (unlikely(!maxlen)) 1263 return -ENOMEM; 1264 1265 __dest = get_loc_data(dest, base); 1266 1267 ret = strncpy_from_user_nofault(__dest, uaddr, maxlen); 1268 if (ret >= 0) 1269 *(u32 *)dest = make_data_loc(ret, __dest - base); 1270 1271 return ret; 1272 } 1273 1274 /* 1275 * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max 1276 * length and relative data location. 1277 */ 1278 static nokprobe_inline int 1279 fetch_store_string(unsigned long addr, void *dest, void *base) 1280 { 1281 int maxlen = get_loc_len(*(u32 *)dest); 1282 void *__dest; 1283 long ret; 1284 1285 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1286 if ((unsigned long)addr < TASK_SIZE) 1287 return fetch_store_string_user(addr, dest, base); 1288 #endif 1289 1290 if (unlikely(!maxlen)) 1291 return -ENOMEM; 1292 1293 __dest = get_loc_data(dest, base); 1294 1295 /* 1296 * Try to get string again, since the string can be changed while 1297 * probing. 1298 */ 1299 ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen); 1300 if (ret >= 0) 1301 *(u32 *)dest = make_data_loc(ret, __dest - base); 1302 1303 return ret; 1304 } 1305 1306 static nokprobe_inline int 1307 probe_mem_read_user(void *dest, void *src, size_t size) 1308 { 1309 const void __user *uaddr = (__force const void __user *)src; 1310 1311 return copy_from_user_nofault(dest, uaddr, size); 1312 } 1313 1314 static nokprobe_inline int 1315 probe_mem_read(void *dest, void *src, size_t size) 1316 { 1317 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1318 if ((unsigned long)src < TASK_SIZE) 1319 return probe_mem_read_user(dest, src, size); 1320 #endif 1321 return copy_from_kernel_nofault(dest, src, size); 1322 } 1323 1324 /* Note that we don't verify it, since the code does not come from user space */ 1325 static int 1326 process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, 1327 void *base) 1328 { 1329 unsigned long val; 1330 1331 retry: 1332 /* 1st stage: get value from context */ 1333 switch (code->op) { 1334 case FETCH_OP_REG: 1335 val = regs_get_register(regs, code->param); 1336 break; 1337 case FETCH_OP_STACK: 1338 val = regs_get_kernel_stack_nth(regs, code->param); 1339 break; 1340 case FETCH_OP_STACKP: 1341 val = kernel_stack_pointer(regs); 1342 break; 1343 case FETCH_OP_RETVAL: 1344 val = regs_return_value(regs); 1345 break; 1346 case FETCH_OP_IMM: 1347 val = code->immediate; 1348 break; 1349 case FETCH_OP_COMM: 1350 val = (unsigned long)current->comm; 1351 break; 1352 case FETCH_OP_DATA: 1353 val = (unsigned long)code->data; 1354 break; 1355 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API 1356 case FETCH_OP_ARG: 1357 val = regs_get_kernel_argument(regs, code->param); 1358 break; 1359 #endif 1360 case FETCH_NOP_SYMBOL: /* Ignore a place holder */ 1361 code++; 1362 goto retry; 1363 default: 1364 return -EILSEQ; 1365 } 1366 code++; 1367 1368 return process_fetch_insn_bottom(code, val, dest, base); 1369 } 1370 NOKPROBE_SYMBOL(process_fetch_insn) 1371 1372 /* Kprobe handler */ 1373 static nokprobe_inline void 1374 __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, 1375 struct trace_event_file *trace_file) 1376 { 1377 struct kprobe_trace_entry_head *entry; 1378 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1379 struct trace_event_buffer fbuffer; 1380 int dsize; 1381 1382 WARN_ON(call != trace_file->event_call); 1383 1384 if (trace_trigger_soft_disabled(trace_file)) 1385 return; 1386 1387 local_save_flags(fbuffer.flags); 1388 fbuffer.pc = preempt_count(); 1389 fbuffer.trace_file = trace_file; 1390 1391 dsize = __get_data_size(&tk->tp, regs); 1392 1393 fbuffer.event = 1394 trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file, 1395 call->event.type, 1396 sizeof(*entry) + tk->tp.size + dsize, 1397 fbuffer.flags, fbuffer.pc); 1398 if (!fbuffer.event) 1399 return; 1400 1401 fbuffer.regs = regs; 1402 entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event); 1403 entry->ip = (unsigned long)tk->rp.kp.addr; 1404 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); 1405 1406 trace_event_buffer_commit(&fbuffer); 1407 } 1408 1409 static void 1410 kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) 1411 { 1412 struct event_file_link *link; 1413 1414 trace_probe_for_each_link_rcu(link, &tk->tp) 1415 __kprobe_trace_func(tk, regs, link->file); 1416 } 1417 NOKPROBE_SYMBOL(kprobe_trace_func); 1418 1419 /* Kretprobe handler */ 1420 static nokprobe_inline void 1421 __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, 1422 struct pt_regs *regs, 1423 struct trace_event_file *trace_file) 1424 { 1425 struct kretprobe_trace_entry_head *entry; 1426 struct trace_event_buffer fbuffer; 1427 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1428 int dsize; 1429 1430 WARN_ON(call != trace_file->event_call); 1431 1432 if (trace_trigger_soft_disabled(trace_file)) 1433 return; 1434 1435 local_save_flags(fbuffer.flags); 1436 fbuffer.pc = preempt_count(); 1437 fbuffer.trace_file = trace_file; 1438 1439 dsize = __get_data_size(&tk->tp, regs); 1440 fbuffer.event = 1441 trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file, 1442 call->event.type, 1443 sizeof(*entry) + tk->tp.size + dsize, 1444 fbuffer.flags, fbuffer.pc); 1445 if (!fbuffer.event) 1446 return; 1447 1448 fbuffer.regs = regs; 1449 entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event); 1450 entry->func = (unsigned long)tk->rp.kp.addr; 1451 entry->ret_ip = (unsigned long)ri->ret_addr; 1452 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); 1453 1454 trace_event_buffer_commit(&fbuffer); 1455 } 1456 1457 static void 1458 kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, 1459 struct pt_regs *regs) 1460 { 1461 struct event_file_link *link; 1462 1463 trace_probe_for_each_link_rcu(link, &tk->tp) 1464 __kretprobe_trace_func(tk, ri, regs, link->file); 1465 } 1466 NOKPROBE_SYMBOL(kretprobe_trace_func); 1467 1468 /* Event entry printers */ 1469 static enum print_line_t 1470 print_kprobe_event(struct trace_iterator *iter, int flags, 1471 struct trace_event *event) 1472 { 1473 struct kprobe_trace_entry_head *field; 1474 struct trace_seq *s = &iter->seq; 1475 struct trace_probe *tp; 1476 1477 field = (struct kprobe_trace_entry_head *)iter->ent; 1478 tp = trace_probe_primary_from_call( 1479 container_of(event, struct trace_event_call, event)); 1480 if (WARN_ON_ONCE(!tp)) 1481 goto out; 1482 1483 trace_seq_printf(s, "%s: (", trace_probe_name(tp)); 1484 1485 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) 1486 goto out; 1487 1488 trace_seq_putc(s, ')'); 1489 1490 if (print_probe_args(s, tp->args, tp->nr_args, 1491 (u8 *)&field[1], field) < 0) 1492 goto out; 1493 1494 trace_seq_putc(s, '\n'); 1495 out: 1496 return trace_handle_return(s); 1497 } 1498 1499 static enum print_line_t 1500 print_kretprobe_event(struct trace_iterator *iter, int flags, 1501 struct trace_event *event) 1502 { 1503 struct kretprobe_trace_entry_head *field; 1504 struct trace_seq *s = &iter->seq; 1505 struct trace_probe *tp; 1506 1507 field = (struct kretprobe_trace_entry_head *)iter->ent; 1508 tp = trace_probe_primary_from_call( 1509 container_of(event, struct trace_event_call, event)); 1510 if (WARN_ON_ONCE(!tp)) 1511 goto out; 1512 1513 trace_seq_printf(s, "%s: (", trace_probe_name(tp)); 1514 1515 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) 1516 goto out; 1517 1518 trace_seq_puts(s, " <- "); 1519 1520 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) 1521 goto out; 1522 1523 trace_seq_putc(s, ')'); 1524 1525 if (print_probe_args(s, tp->args, tp->nr_args, 1526 (u8 *)&field[1], field) < 0) 1527 goto out; 1528 1529 trace_seq_putc(s, '\n'); 1530 1531 out: 1532 return trace_handle_return(s); 1533 } 1534 1535 1536 static int kprobe_event_define_fields(struct trace_event_call *event_call) 1537 { 1538 int ret; 1539 struct kprobe_trace_entry_head field; 1540 struct trace_probe *tp; 1541 1542 tp = trace_probe_primary_from_call(event_call); 1543 if (WARN_ON_ONCE(!tp)) 1544 return -ENOENT; 1545 1546 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); 1547 1548 return traceprobe_define_arg_fields(event_call, sizeof(field), tp); 1549 } 1550 1551 static int kretprobe_event_define_fields(struct trace_event_call *event_call) 1552 { 1553 int ret; 1554 struct kretprobe_trace_entry_head field; 1555 struct trace_probe *tp; 1556 1557 tp = trace_probe_primary_from_call(event_call); 1558 if (WARN_ON_ONCE(!tp)) 1559 return -ENOENT; 1560 1561 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); 1562 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); 1563 1564 return traceprobe_define_arg_fields(event_call, sizeof(field), tp); 1565 } 1566 1567 #ifdef CONFIG_PERF_EVENTS 1568 1569 /* Kprobe profile handler */ 1570 static int 1571 kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) 1572 { 1573 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1574 struct kprobe_trace_entry_head *entry; 1575 struct hlist_head *head; 1576 int size, __size, dsize; 1577 int rctx; 1578 1579 if (bpf_prog_array_valid(call)) { 1580 unsigned long orig_ip = instruction_pointer(regs); 1581 int ret; 1582 1583 ret = trace_call_bpf(call, regs); 1584 1585 /* 1586 * We need to check and see if we modified the pc of the 1587 * pt_regs, and if so return 1 so that we don't do the 1588 * single stepping. 1589 */ 1590 if (orig_ip != instruction_pointer(regs)) 1591 return 1; 1592 if (!ret) 1593 return 0; 1594 } 1595 1596 head = this_cpu_ptr(call->perf_events); 1597 if (hlist_empty(head)) 1598 return 0; 1599 1600 dsize = __get_data_size(&tk->tp, regs); 1601 __size = sizeof(*entry) + tk->tp.size + dsize; 1602 size = ALIGN(__size + sizeof(u32), sizeof(u64)); 1603 size -= sizeof(u32); 1604 1605 entry = perf_trace_buf_alloc(size, NULL, &rctx); 1606 if (!entry) 1607 return 0; 1608 1609 entry->ip = (unsigned long)tk->rp.kp.addr; 1610 memset(&entry[1], 0, dsize); 1611 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); 1612 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, 1613 head, NULL); 1614 return 0; 1615 } 1616 NOKPROBE_SYMBOL(kprobe_perf_func); 1617 1618 /* Kretprobe profile handler */ 1619 static void 1620 kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, 1621 struct pt_regs *regs) 1622 { 1623 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1624 struct kretprobe_trace_entry_head *entry; 1625 struct hlist_head *head; 1626 int size, __size, dsize; 1627 int rctx; 1628 1629 if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs)) 1630 return; 1631 1632 head = this_cpu_ptr(call->perf_events); 1633 if (hlist_empty(head)) 1634 return; 1635 1636 dsize = __get_data_size(&tk->tp, regs); 1637 __size = sizeof(*entry) + tk->tp.size + dsize; 1638 size = ALIGN(__size + sizeof(u32), sizeof(u64)); 1639 size -= sizeof(u32); 1640 1641 entry = perf_trace_buf_alloc(size, NULL, &rctx); 1642 if (!entry) 1643 return; 1644 1645 entry->func = (unsigned long)tk->rp.kp.addr; 1646 entry->ret_ip = (unsigned long)ri->ret_addr; 1647 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); 1648 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, 1649 head, NULL); 1650 } 1651 NOKPROBE_SYMBOL(kretprobe_perf_func); 1652 1653 int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type, 1654 const char **symbol, u64 *probe_offset, 1655 u64 *probe_addr, bool perf_type_tracepoint) 1656 { 1657 const char *pevent = trace_event_name(event->tp_event); 1658 const char *group = event->tp_event->class->system; 1659 struct trace_kprobe *tk; 1660 1661 if (perf_type_tracepoint) 1662 tk = find_trace_kprobe(pevent, group); 1663 else 1664 tk = trace_kprobe_primary_from_call(event->tp_event); 1665 if (!tk) 1666 return -EINVAL; 1667 1668 *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE 1669 : BPF_FD_TYPE_KPROBE; 1670 if (tk->symbol) { 1671 *symbol = tk->symbol; 1672 *probe_offset = tk->rp.kp.offset; 1673 *probe_addr = 0; 1674 } else { 1675 *symbol = NULL; 1676 *probe_offset = 0; 1677 *probe_addr = (unsigned long)tk->rp.kp.addr; 1678 } 1679 return 0; 1680 } 1681 #endif /* CONFIG_PERF_EVENTS */ 1682 1683 /* 1684 * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. 1685 * 1686 * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe 1687 * lockless, but we can't race with this __init function. 1688 */ 1689 static int kprobe_register(struct trace_event_call *event, 1690 enum trace_reg type, void *data) 1691 { 1692 struct trace_event_file *file = data; 1693 1694 switch (type) { 1695 case TRACE_REG_REGISTER: 1696 return enable_trace_kprobe(event, file); 1697 case TRACE_REG_UNREGISTER: 1698 return disable_trace_kprobe(event, file); 1699 1700 #ifdef CONFIG_PERF_EVENTS 1701 case TRACE_REG_PERF_REGISTER: 1702 return enable_trace_kprobe(event, NULL); 1703 case TRACE_REG_PERF_UNREGISTER: 1704 return disable_trace_kprobe(event, NULL); 1705 case TRACE_REG_PERF_OPEN: 1706 case TRACE_REG_PERF_CLOSE: 1707 case TRACE_REG_PERF_ADD: 1708 case TRACE_REG_PERF_DEL: 1709 return 0; 1710 #endif 1711 } 1712 return 0; 1713 } 1714 1715 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) 1716 { 1717 struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); 1718 int ret = 0; 1719 1720 raw_cpu_inc(*tk->nhit); 1721 1722 if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) 1723 kprobe_trace_func(tk, regs); 1724 #ifdef CONFIG_PERF_EVENTS 1725 if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) 1726 ret = kprobe_perf_func(tk, regs); 1727 #endif 1728 return ret; 1729 } 1730 NOKPROBE_SYMBOL(kprobe_dispatcher); 1731 1732 static int 1733 kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) 1734 { 1735 struct kretprobe *rp = get_kretprobe(ri); 1736 struct trace_kprobe *tk = container_of(rp, struct trace_kprobe, rp); 1737 1738 raw_cpu_inc(*tk->nhit); 1739 1740 if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) 1741 kretprobe_trace_func(tk, ri, regs); 1742 #ifdef CONFIG_PERF_EVENTS 1743 if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) 1744 kretprobe_perf_func(tk, ri, regs); 1745 #endif 1746 return 0; /* We don't tweek kernel, so just return 0 */ 1747 } 1748 NOKPROBE_SYMBOL(kretprobe_dispatcher); 1749 1750 static struct trace_event_functions kretprobe_funcs = { 1751 .trace = print_kretprobe_event 1752 }; 1753 1754 static struct trace_event_functions kprobe_funcs = { 1755 .trace = print_kprobe_event 1756 }; 1757 1758 static struct trace_event_fields kretprobe_fields_array[] = { 1759 { .type = TRACE_FUNCTION_TYPE, 1760 .define_fields = kretprobe_event_define_fields }, 1761 {} 1762 }; 1763 1764 static struct trace_event_fields kprobe_fields_array[] = { 1765 { .type = TRACE_FUNCTION_TYPE, 1766 .define_fields = kprobe_event_define_fields }, 1767 {} 1768 }; 1769 1770 static inline void init_trace_event_call(struct trace_kprobe *tk) 1771 { 1772 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1773 1774 if (trace_kprobe_is_return(tk)) { 1775 call->event.funcs = &kretprobe_funcs; 1776 call->class->fields_array = kretprobe_fields_array; 1777 } else { 1778 call->event.funcs = &kprobe_funcs; 1779 call->class->fields_array = kprobe_fields_array; 1780 } 1781 1782 call->flags = TRACE_EVENT_FL_KPROBE; 1783 call->class->reg = kprobe_register; 1784 } 1785 1786 static int register_kprobe_event(struct trace_kprobe *tk) 1787 { 1788 init_trace_event_call(tk); 1789 1790 return trace_probe_register_event_call(&tk->tp); 1791 } 1792 1793 static int unregister_kprobe_event(struct trace_kprobe *tk) 1794 { 1795 return trace_probe_unregister_event_call(&tk->tp); 1796 } 1797 1798 #ifdef CONFIG_PERF_EVENTS 1799 /* create a trace_kprobe, but don't add it to global lists */ 1800 struct trace_event_call * 1801 create_local_trace_kprobe(char *func, void *addr, unsigned long offs, 1802 bool is_return) 1803 { 1804 struct trace_kprobe *tk; 1805 int ret; 1806 char *event; 1807 1808 /* 1809 * local trace_kprobes are not added to dyn_event, so they are never 1810 * searched in find_trace_kprobe(). Therefore, there is no concern of 1811 * duplicated name here. 1812 */ 1813 event = func ? func : "DUMMY_EVENT"; 1814 1815 tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func, 1816 offs, 0 /* maxactive */, 0 /* nargs */, 1817 is_return); 1818 1819 if (IS_ERR(tk)) { 1820 pr_info("Failed to allocate trace_probe.(%d)\n", 1821 (int)PTR_ERR(tk)); 1822 return ERR_CAST(tk); 1823 } 1824 1825 init_trace_event_call(tk); 1826 1827 if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) { 1828 ret = -ENOMEM; 1829 goto error; 1830 } 1831 1832 ret = __register_trace_kprobe(tk); 1833 if (ret < 0) 1834 goto error; 1835 1836 return trace_probe_event_call(&tk->tp); 1837 error: 1838 free_trace_kprobe(tk); 1839 return ERR_PTR(ret); 1840 } 1841 1842 void destroy_local_trace_kprobe(struct trace_event_call *event_call) 1843 { 1844 struct trace_kprobe *tk; 1845 1846 tk = trace_kprobe_primary_from_call(event_call); 1847 if (unlikely(!tk)) 1848 return; 1849 1850 if (trace_probe_is_enabled(&tk->tp)) { 1851 WARN_ON(1); 1852 return; 1853 } 1854 1855 __unregister_trace_kprobe(tk); 1856 1857 free_trace_kprobe(tk); 1858 } 1859 #endif /* CONFIG_PERF_EVENTS */ 1860 1861 static __init void enable_boot_kprobe_events(void) 1862 { 1863 struct trace_array *tr = top_trace_array(); 1864 struct trace_event_file *file; 1865 struct trace_kprobe *tk; 1866 struct dyn_event *pos; 1867 1868 mutex_lock(&event_mutex); 1869 for_each_trace_kprobe(tk, pos) { 1870 list_for_each_entry(file, &tr->events, list) 1871 if (file->event_call == trace_probe_event_call(&tk->tp)) 1872 trace_event_enable_disable(file, 1, 0); 1873 } 1874 mutex_unlock(&event_mutex); 1875 } 1876 1877 static __init void setup_boot_kprobe_events(void) 1878 { 1879 char *p, *cmd = kprobe_boot_events_buf; 1880 int ret; 1881 1882 strreplace(kprobe_boot_events_buf, ',', ' '); 1883 1884 while (cmd && *cmd != '\0') { 1885 p = strchr(cmd, ';'); 1886 if (p) 1887 *p++ = '\0'; 1888 1889 ret = trace_run_command(cmd, create_or_delete_trace_kprobe); 1890 if (ret) 1891 pr_warn("Failed to add event(%d): %s\n", ret, cmd); 1892 1893 cmd = p; 1894 } 1895 1896 enable_boot_kprobe_events(); 1897 } 1898 1899 /* 1900 * Register dynevent at core_initcall. This allows kernel to setup kprobe 1901 * events in postcore_initcall without tracefs. 1902 */ 1903 static __init int init_kprobe_trace_early(void) 1904 { 1905 int ret; 1906 1907 ret = dyn_event_register(&trace_kprobe_ops); 1908 if (ret) 1909 return ret; 1910 1911 if (register_module_notifier(&trace_kprobe_module_nb)) 1912 return -EINVAL; 1913 1914 return 0; 1915 } 1916 core_initcall(init_kprobe_trace_early); 1917 1918 /* Make a tracefs interface for controlling probe points */ 1919 static __init int init_kprobe_trace(void) 1920 { 1921 int ret; 1922 struct dentry *entry; 1923 1924 ret = tracing_init_dentry(); 1925 if (ret) 1926 return 0; 1927 1928 entry = tracefs_create_file("kprobe_events", 0644, NULL, 1929 NULL, &kprobe_events_ops); 1930 1931 /* Event list interface */ 1932 if (!entry) 1933 pr_warn("Could not create tracefs 'kprobe_events' entry\n"); 1934 1935 /* Profile interface */ 1936 entry = tracefs_create_file("kprobe_profile", 0444, NULL, 1937 NULL, &kprobe_profile_ops); 1938 1939 if (!entry) 1940 pr_warn("Could not create tracefs 'kprobe_profile' entry\n"); 1941 1942 setup_boot_kprobe_events(); 1943 1944 return 0; 1945 } 1946 fs_initcall(init_kprobe_trace); 1947 1948 1949 #ifdef CONFIG_FTRACE_STARTUP_TEST 1950 static __init struct trace_event_file * 1951 find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) 1952 { 1953 struct trace_event_file *file; 1954 1955 list_for_each_entry(file, &tr->events, list) 1956 if (file->event_call == trace_probe_event_call(&tk->tp)) 1957 return file; 1958 1959 return NULL; 1960 } 1961 1962 /* 1963 * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this 1964 * stage, we can do this lockless. 1965 */ 1966 static __init int kprobe_trace_self_tests_init(void) 1967 { 1968 int ret, warn = 0; 1969 int (*target)(int, int, int, int, int, int); 1970 struct trace_kprobe *tk; 1971 struct trace_event_file *file; 1972 1973 if (tracing_is_disabled()) 1974 return -ENODEV; 1975 1976 if (tracing_selftest_disabled) 1977 return 0; 1978 1979 target = kprobe_trace_selftest_target; 1980 1981 pr_info("Testing kprobe tracing: "); 1982 1983 ret = trace_run_command("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)", 1984 create_or_delete_trace_kprobe); 1985 if (WARN_ON_ONCE(ret)) { 1986 pr_warn("error on probing function entry.\n"); 1987 warn++; 1988 } else { 1989 /* Enable trace point */ 1990 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); 1991 if (WARN_ON_ONCE(tk == NULL)) { 1992 pr_warn("error on getting new probe.\n"); 1993 warn++; 1994 } else { 1995 file = find_trace_probe_file(tk, top_trace_array()); 1996 if (WARN_ON_ONCE(file == NULL)) { 1997 pr_warn("error on getting probe file.\n"); 1998 warn++; 1999 } else 2000 enable_trace_kprobe( 2001 trace_probe_event_call(&tk->tp), file); 2002 } 2003 } 2004 2005 ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target $retval", 2006 create_or_delete_trace_kprobe); 2007 if (WARN_ON_ONCE(ret)) { 2008 pr_warn("error on probing function return.\n"); 2009 warn++; 2010 } else { 2011 /* Enable trace point */ 2012 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); 2013 if (WARN_ON_ONCE(tk == NULL)) { 2014 pr_warn("error on getting 2nd new probe.\n"); 2015 warn++; 2016 } else { 2017 file = find_trace_probe_file(tk, top_trace_array()); 2018 if (WARN_ON_ONCE(file == NULL)) { 2019 pr_warn("error on getting probe file.\n"); 2020 warn++; 2021 } else 2022 enable_trace_kprobe( 2023 trace_probe_event_call(&tk->tp), file); 2024 } 2025 } 2026 2027 if (warn) 2028 goto end; 2029 2030 ret = target(1, 2, 3, 4, 5, 6); 2031 2032 /* 2033 * Not expecting an error here, the check is only to prevent the 2034 * optimizer from removing the call to target() as otherwise there 2035 * are no side-effects and the call is never performed. 2036 */ 2037 if (ret != 21) 2038 warn++; 2039 2040 /* Disable trace points before removing it */ 2041 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); 2042 if (WARN_ON_ONCE(tk == NULL)) { 2043 pr_warn("error on getting test probe.\n"); 2044 warn++; 2045 } else { 2046 if (trace_kprobe_nhit(tk) != 1) { 2047 pr_warn("incorrect number of testprobe hits\n"); 2048 warn++; 2049 } 2050 2051 file = find_trace_probe_file(tk, top_trace_array()); 2052 if (WARN_ON_ONCE(file == NULL)) { 2053 pr_warn("error on getting probe file.\n"); 2054 warn++; 2055 } else 2056 disable_trace_kprobe( 2057 trace_probe_event_call(&tk->tp), file); 2058 } 2059 2060 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); 2061 if (WARN_ON_ONCE(tk == NULL)) { 2062 pr_warn("error on getting 2nd test probe.\n"); 2063 warn++; 2064 } else { 2065 if (trace_kprobe_nhit(tk) != 1) { 2066 pr_warn("incorrect number of testprobe2 hits\n"); 2067 warn++; 2068 } 2069 2070 file = find_trace_probe_file(tk, top_trace_array()); 2071 if (WARN_ON_ONCE(file == NULL)) { 2072 pr_warn("error on getting probe file.\n"); 2073 warn++; 2074 } else 2075 disable_trace_kprobe( 2076 trace_probe_event_call(&tk->tp), file); 2077 } 2078 2079 ret = trace_run_command("-:testprobe", create_or_delete_trace_kprobe); 2080 if (WARN_ON_ONCE(ret)) { 2081 pr_warn("error on deleting a probe.\n"); 2082 warn++; 2083 } 2084 2085 ret = trace_run_command("-:testprobe2", create_or_delete_trace_kprobe); 2086 if (WARN_ON_ONCE(ret)) { 2087 pr_warn("error on deleting a probe.\n"); 2088 warn++; 2089 } 2090 2091 end: 2092 ret = dyn_events_release_all(&trace_kprobe_ops); 2093 if (WARN_ON_ONCE(ret)) { 2094 pr_warn("error on cleaning up probes.\n"); 2095 warn++; 2096 } 2097 /* 2098 * Wait for the optimizer work to finish. Otherwise it might fiddle 2099 * with probes in already freed __init text. 2100 */ 2101 wait_for_kprobe_optimizer(); 2102 if (warn) 2103 pr_cont("NG: Some tests are failed. Please check them.\n"); 2104 else 2105 pr_cont("OK\n"); 2106 return 0; 2107 } 2108 2109 late_initcall(kprobe_trace_self_tests_init); 2110 2111 #endif 2112