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) == 0) : 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 ret = kprobe_on_func_entry(NULL, symbol, offset); 832 if (ret == 0) 833 flags |= TPARG_FL_FENTRY; 834 /* Defer the ENOENT case until register kprobe */ 835 if (ret == -EINVAL && is_return) { 836 trace_probe_log_err(0, BAD_RETPROBE); 837 goto parse_error; 838 } 839 } 840 841 trace_probe_log_set_index(0); 842 if (event) { 843 ret = traceprobe_parse_event_name(&event, &group, buf, 844 event - argv[0]); 845 if (ret) 846 goto parse_error; 847 } else { 848 /* Make a new event name */ 849 if (symbol) 850 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", 851 is_return ? 'r' : 'p', symbol, offset); 852 else 853 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", 854 is_return ? 'r' : 'p', addr); 855 sanitize_event_name(buf); 856 event = buf; 857 } 858 859 /* setup a probe */ 860 tk = alloc_trace_kprobe(group, event, addr, symbol, offset, maxactive, 861 argc - 2, is_return); 862 if (IS_ERR(tk)) { 863 ret = PTR_ERR(tk); 864 /* This must return -ENOMEM, else there is a bug */ 865 WARN_ON_ONCE(ret != -ENOMEM); 866 goto out; /* We know tk is not allocated */ 867 } 868 argc -= 2; argv += 2; 869 870 /* parse arguments */ 871 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { 872 tmp = kstrdup(argv[i], GFP_KERNEL); 873 if (!tmp) { 874 ret = -ENOMEM; 875 goto error; 876 } 877 878 trace_probe_log_set_index(i + 2); 879 ret = traceprobe_parse_probe_arg(&tk->tp, i, tmp, flags); 880 kfree(tmp); 881 if (ret) 882 goto error; /* This can be -ENOMEM */ 883 } 884 885 ret = traceprobe_set_print_fmt(&tk->tp, is_return); 886 if (ret < 0) 887 goto error; 888 889 ret = register_trace_kprobe(tk); 890 if (ret) { 891 trace_probe_log_set_index(1); 892 if (ret == -EILSEQ) 893 trace_probe_log_err(0, BAD_INSN_BNDRY); 894 else if (ret == -ENOENT) 895 trace_probe_log_err(0, BAD_PROBE_ADDR); 896 else if (ret != -ENOMEM && ret != -EEXIST) 897 trace_probe_log_err(0, FAIL_REG_PROBE); 898 goto error; 899 } 900 901 out: 902 trace_probe_log_clear(); 903 kfree(symbol); 904 return ret; 905 906 parse_error: 907 ret = -EINVAL; 908 error: 909 free_trace_kprobe(tk); 910 goto out; 911 } 912 913 static int create_or_delete_trace_kprobe(int argc, char **argv) 914 { 915 int ret; 916 917 if (argv[0][0] == '-') 918 return dyn_event_release(argc, argv, &trace_kprobe_ops); 919 920 ret = trace_kprobe_create(argc, (const char **)argv); 921 return ret == -ECANCELED ? -EINVAL : ret; 922 } 923 924 static int trace_kprobe_run_command(struct dynevent_cmd *cmd) 925 { 926 return trace_run_command(cmd->seq.buffer, create_or_delete_trace_kprobe); 927 } 928 929 /** 930 * kprobe_event_cmd_init - Initialize a kprobe event command object 931 * @cmd: A pointer to the dynevent_cmd struct representing the new event 932 * @buf: A pointer to the buffer used to build the command 933 * @maxlen: The length of the buffer passed in @buf 934 * 935 * Initialize a synthetic event command object. Use this before 936 * calling any of the other kprobe_event functions. 937 */ 938 void kprobe_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen) 939 { 940 dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_KPROBE, 941 trace_kprobe_run_command); 942 } 943 EXPORT_SYMBOL_GPL(kprobe_event_cmd_init); 944 945 /** 946 * __kprobe_event_gen_cmd_start - Generate a kprobe event command from arg list 947 * @cmd: A pointer to the dynevent_cmd struct representing the new event 948 * @name: The name of the kprobe event 949 * @loc: The location of the kprobe event 950 * @kretprobe: Is this a return probe? 951 * @args: Variable number of arg (pairs), one pair for each field 952 * 953 * NOTE: Users normally won't want to call this function directly, but 954 * rather use the kprobe_event_gen_cmd_start() wrapper, which automatically 955 * adds a NULL to the end of the arg list. If this function is used 956 * directly, make sure the last arg in the variable arg list is NULL. 957 * 958 * Generate a kprobe event command to be executed by 959 * kprobe_event_gen_cmd_end(). This function can be used to generate the 960 * complete command or only the first part of it; in the latter case, 961 * kprobe_event_add_fields() can be used to add more fields following this. 962 * 963 * Unlikely the synth_event_gen_cmd_start(), @loc must be specified. This 964 * returns -EINVAL if @loc == NULL. 965 * 966 * Return: 0 if successful, error otherwise. 967 */ 968 int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe, 969 const char *name, const char *loc, ...) 970 { 971 char buf[MAX_EVENT_NAME_LEN]; 972 struct dynevent_arg arg; 973 va_list args; 974 int ret; 975 976 if (cmd->type != DYNEVENT_TYPE_KPROBE) 977 return -EINVAL; 978 979 if (!loc) 980 return -EINVAL; 981 982 if (kretprobe) 983 snprintf(buf, MAX_EVENT_NAME_LEN, "r:kprobes/%s", name); 984 else 985 snprintf(buf, MAX_EVENT_NAME_LEN, "p:kprobes/%s", name); 986 987 ret = dynevent_str_add(cmd, buf); 988 if (ret) 989 return ret; 990 991 dynevent_arg_init(&arg, 0); 992 arg.str = loc; 993 ret = dynevent_arg_add(cmd, &arg, NULL); 994 if (ret) 995 return ret; 996 997 va_start(args, loc); 998 for (;;) { 999 const char *field; 1000 1001 field = va_arg(args, const char *); 1002 if (!field) 1003 break; 1004 1005 if (++cmd->n_fields > MAX_TRACE_ARGS) { 1006 ret = -EINVAL; 1007 break; 1008 } 1009 1010 arg.str = field; 1011 ret = dynevent_arg_add(cmd, &arg, NULL); 1012 if (ret) 1013 break; 1014 } 1015 va_end(args); 1016 1017 return ret; 1018 } 1019 EXPORT_SYMBOL_GPL(__kprobe_event_gen_cmd_start); 1020 1021 /** 1022 * __kprobe_event_add_fields - Add probe fields to a kprobe command from arg list 1023 * @cmd: A pointer to the dynevent_cmd struct representing the new event 1024 * @args: Variable number of arg (pairs), one pair for each field 1025 * 1026 * NOTE: Users normally won't want to call this function directly, but 1027 * rather use the kprobe_event_add_fields() wrapper, which 1028 * automatically adds a NULL to the end of the arg list. If this 1029 * function is used directly, make sure the last arg in the variable 1030 * arg list is NULL. 1031 * 1032 * Add probe fields to an existing kprobe command using a variable 1033 * list of args. Fields are added in the same order they're listed. 1034 * 1035 * Return: 0 if successful, error otherwise. 1036 */ 1037 int __kprobe_event_add_fields(struct dynevent_cmd *cmd, ...) 1038 { 1039 struct dynevent_arg arg; 1040 va_list args; 1041 int ret = 0; 1042 1043 if (cmd->type != DYNEVENT_TYPE_KPROBE) 1044 return -EINVAL; 1045 1046 dynevent_arg_init(&arg, 0); 1047 1048 va_start(args, cmd); 1049 for (;;) { 1050 const char *field; 1051 1052 field = va_arg(args, const char *); 1053 if (!field) 1054 break; 1055 1056 if (++cmd->n_fields > MAX_TRACE_ARGS) { 1057 ret = -EINVAL; 1058 break; 1059 } 1060 1061 arg.str = field; 1062 ret = dynevent_arg_add(cmd, &arg, NULL); 1063 if (ret) 1064 break; 1065 } 1066 va_end(args); 1067 1068 return ret; 1069 } 1070 EXPORT_SYMBOL_GPL(__kprobe_event_add_fields); 1071 1072 /** 1073 * kprobe_event_delete - Delete a kprobe event 1074 * @name: The name of the kprobe event to delete 1075 * 1076 * Delete a kprobe event with the give @name from kernel code rather 1077 * than directly from the command line. 1078 * 1079 * Return: 0 if successful, error otherwise. 1080 */ 1081 int kprobe_event_delete(const char *name) 1082 { 1083 char buf[MAX_EVENT_NAME_LEN]; 1084 1085 snprintf(buf, MAX_EVENT_NAME_LEN, "-:%s", name); 1086 1087 return trace_run_command(buf, create_or_delete_trace_kprobe); 1088 } 1089 EXPORT_SYMBOL_GPL(kprobe_event_delete); 1090 1091 static int trace_kprobe_release(struct dyn_event *ev) 1092 { 1093 struct trace_kprobe *tk = to_trace_kprobe(ev); 1094 int ret = unregister_trace_kprobe(tk); 1095 1096 if (!ret) 1097 free_trace_kprobe(tk); 1098 return ret; 1099 } 1100 1101 static int trace_kprobe_show(struct seq_file *m, struct dyn_event *ev) 1102 { 1103 struct trace_kprobe *tk = to_trace_kprobe(ev); 1104 int i; 1105 1106 seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p'); 1107 if (trace_kprobe_is_return(tk) && tk->rp.maxactive) 1108 seq_printf(m, "%d", tk->rp.maxactive); 1109 seq_printf(m, ":%s/%s", trace_probe_group_name(&tk->tp), 1110 trace_probe_name(&tk->tp)); 1111 1112 if (!tk->symbol) 1113 seq_printf(m, " 0x%p", tk->rp.kp.addr); 1114 else if (tk->rp.kp.offset) 1115 seq_printf(m, " %s+%u", trace_kprobe_symbol(tk), 1116 tk->rp.kp.offset); 1117 else 1118 seq_printf(m, " %s", trace_kprobe_symbol(tk)); 1119 1120 for (i = 0; i < tk->tp.nr_args; i++) 1121 seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm); 1122 seq_putc(m, '\n'); 1123 1124 return 0; 1125 } 1126 1127 static int probes_seq_show(struct seq_file *m, void *v) 1128 { 1129 struct dyn_event *ev = v; 1130 1131 if (!is_trace_kprobe(ev)) 1132 return 0; 1133 1134 return trace_kprobe_show(m, ev); 1135 } 1136 1137 static const struct seq_operations probes_seq_op = { 1138 .start = dyn_event_seq_start, 1139 .next = dyn_event_seq_next, 1140 .stop = dyn_event_seq_stop, 1141 .show = probes_seq_show 1142 }; 1143 1144 static int probes_open(struct inode *inode, struct file *file) 1145 { 1146 int ret; 1147 1148 ret = security_locked_down(LOCKDOWN_TRACEFS); 1149 if (ret) 1150 return ret; 1151 1152 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { 1153 ret = dyn_events_release_all(&trace_kprobe_ops); 1154 if (ret < 0) 1155 return ret; 1156 } 1157 1158 return seq_open(file, &probes_seq_op); 1159 } 1160 1161 static ssize_t probes_write(struct file *file, const char __user *buffer, 1162 size_t count, loff_t *ppos) 1163 { 1164 return trace_parse_run_command(file, buffer, count, ppos, 1165 create_or_delete_trace_kprobe); 1166 } 1167 1168 static const struct file_operations kprobe_events_ops = { 1169 .owner = THIS_MODULE, 1170 .open = probes_open, 1171 .read = seq_read, 1172 .llseek = seq_lseek, 1173 .release = seq_release, 1174 .write = probes_write, 1175 }; 1176 1177 /* Probes profiling interfaces */ 1178 static int probes_profile_seq_show(struct seq_file *m, void *v) 1179 { 1180 struct dyn_event *ev = v; 1181 struct trace_kprobe *tk; 1182 1183 if (!is_trace_kprobe(ev)) 1184 return 0; 1185 1186 tk = to_trace_kprobe(ev); 1187 seq_printf(m, " %-44s %15lu %15lu\n", 1188 trace_probe_name(&tk->tp), 1189 trace_kprobe_nhit(tk), 1190 tk->rp.kp.nmissed); 1191 1192 return 0; 1193 } 1194 1195 static const struct seq_operations profile_seq_op = { 1196 .start = dyn_event_seq_start, 1197 .next = dyn_event_seq_next, 1198 .stop = dyn_event_seq_stop, 1199 .show = probes_profile_seq_show 1200 }; 1201 1202 static int profile_open(struct inode *inode, struct file *file) 1203 { 1204 int ret; 1205 1206 ret = security_locked_down(LOCKDOWN_TRACEFS); 1207 if (ret) 1208 return ret; 1209 1210 return seq_open(file, &profile_seq_op); 1211 } 1212 1213 static const struct file_operations kprobe_profile_ops = { 1214 .owner = THIS_MODULE, 1215 .open = profile_open, 1216 .read = seq_read, 1217 .llseek = seq_lseek, 1218 .release = seq_release, 1219 }; 1220 1221 /* Kprobe specific fetch functions */ 1222 1223 /* Return the length of string -- including null terminal byte */ 1224 static nokprobe_inline int 1225 fetch_store_strlen_user(unsigned long addr) 1226 { 1227 const void __user *uaddr = (__force const void __user *)addr; 1228 1229 return strnlen_user_nofault(uaddr, MAX_STRING_SIZE); 1230 } 1231 1232 /* Return the length of string -- including null terminal byte */ 1233 static nokprobe_inline int 1234 fetch_store_strlen(unsigned long addr) 1235 { 1236 int ret, len = 0; 1237 u8 c; 1238 1239 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1240 if (addr < TASK_SIZE) 1241 return fetch_store_strlen_user(addr); 1242 #endif 1243 1244 do { 1245 ret = copy_from_kernel_nofault(&c, (u8 *)addr + len, 1); 1246 len++; 1247 } while (c && ret == 0 && len < MAX_STRING_SIZE); 1248 1249 return (ret < 0) ? ret : len; 1250 } 1251 1252 /* 1253 * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf 1254 * with max length and relative data location. 1255 */ 1256 static nokprobe_inline int 1257 fetch_store_string_user(unsigned long addr, void *dest, void *base) 1258 { 1259 const void __user *uaddr = (__force const void __user *)addr; 1260 int maxlen = get_loc_len(*(u32 *)dest); 1261 void *__dest; 1262 long ret; 1263 1264 if (unlikely(!maxlen)) 1265 return -ENOMEM; 1266 1267 __dest = get_loc_data(dest, base); 1268 1269 ret = strncpy_from_user_nofault(__dest, uaddr, maxlen); 1270 if (ret >= 0) 1271 *(u32 *)dest = make_data_loc(ret, __dest - base); 1272 1273 return ret; 1274 } 1275 1276 /* 1277 * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max 1278 * length and relative data location. 1279 */ 1280 static nokprobe_inline int 1281 fetch_store_string(unsigned long addr, void *dest, void *base) 1282 { 1283 int maxlen = get_loc_len(*(u32 *)dest); 1284 void *__dest; 1285 long ret; 1286 1287 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1288 if ((unsigned long)addr < TASK_SIZE) 1289 return fetch_store_string_user(addr, dest, base); 1290 #endif 1291 1292 if (unlikely(!maxlen)) 1293 return -ENOMEM; 1294 1295 __dest = get_loc_data(dest, base); 1296 1297 /* 1298 * Try to get string again, since the string can be changed while 1299 * probing. 1300 */ 1301 ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen); 1302 if (ret >= 0) 1303 *(u32 *)dest = make_data_loc(ret, __dest - base); 1304 1305 return ret; 1306 } 1307 1308 static nokprobe_inline int 1309 probe_mem_read_user(void *dest, void *src, size_t size) 1310 { 1311 const void __user *uaddr = (__force const void __user *)src; 1312 1313 return copy_from_user_nofault(dest, uaddr, size); 1314 } 1315 1316 static nokprobe_inline int 1317 probe_mem_read(void *dest, void *src, size_t size) 1318 { 1319 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 1320 if ((unsigned long)src < TASK_SIZE) 1321 return probe_mem_read_user(dest, src, size); 1322 #endif 1323 return copy_from_kernel_nofault(dest, src, size); 1324 } 1325 1326 /* Note that we don't verify it, since the code does not come from user space */ 1327 static int 1328 process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, 1329 void *base) 1330 { 1331 unsigned long val; 1332 1333 retry: 1334 /* 1st stage: get value from context */ 1335 switch (code->op) { 1336 case FETCH_OP_REG: 1337 val = regs_get_register(regs, code->param); 1338 break; 1339 case FETCH_OP_STACK: 1340 val = regs_get_kernel_stack_nth(regs, code->param); 1341 break; 1342 case FETCH_OP_STACKP: 1343 val = kernel_stack_pointer(regs); 1344 break; 1345 case FETCH_OP_RETVAL: 1346 val = regs_return_value(regs); 1347 break; 1348 case FETCH_OP_IMM: 1349 val = code->immediate; 1350 break; 1351 case FETCH_OP_COMM: 1352 val = (unsigned long)current->comm; 1353 break; 1354 case FETCH_OP_DATA: 1355 val = (unsigned long)code->data; 1356 break; 1357 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API 1358 case FETCH_OP_ARG: 1359 val = regs_get_kernel_argument(regs, code->param); 1360 break; 1361 #endif 1362 case FETCH_NOP_SYMBOL: /* Ignore a place holder */ 1363 code++; 1364 goto retry; 1365 default: 1366 return -EILSEQ; 1367 } 1368 code++; 1369 1370 return process_fetch_insn_bottom(code, val, dest, base); 1371 } 1372 NOKPROBE_SYMBOL(process_fetch_insn) 1373 1374 /* Kprobe handler */ 1375 static nokprobe_inline void 1376 __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, 1377 struct trace_event_file *trace_file) 1378 { 1379 struct kprobe_trace_entry_head *entry; 1380 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1381 struct trace_event_buffer fbuffer; 1382 int dsize; 1383 1384 WARN_ON(call != trace_file->event_call); 1385 1386 if (trace_trigger_soft_disabled(trace_file)) 1387 return; 1388 1389 local_save_flags(fbuffer.flags); 1390 fbuffer.pc = preempt_count(); 1391 fbuffer.trace_file = trace_file; 1392 1393 dsize = __get_data_size(&tk->tp, regs); 1394 1395 fbuffer.event = 1396 trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file, 1397 call->event.type, 1398 sizeof(*entry) + tk->tp.size + dsize, 1399 fbuffer.flags, fbuffer.pc); 1400 if (!fbuffer.event) 1401 return; 1402 1403 fbuffer.regs = regs; 1404 entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event); 1405 entry->ip = (unsigned long)tk->rp.kp.addr; 1406 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); 1407 1408 trace_event_buffer_commit(&fbuffer); 1409 } 1410 1411 static void 1412 kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) 1413 { 1414 struct event_file_link *link; 1415 1416 trace_probe_for_each_link_rcu(link, &tk->tp) 1417 __kprobe_trace_func(tk, regs, link->file); 1418 } 1419 NOKPROBE_SYMBOL(kprobe_trace_func); 1420 1421 /* Kretprobe handler */ 1422 static nokprobe_inline void 1423 __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, 1424 struct pt_regs *regs, 1425 struct trace_event_file *trace_file) 1426 { 1427 struct kretprobe_trace_entry_head *entry; 1428 struct trace_event_buffer fbuffer; 1429 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1430 int dsize; 1431 1432 WARN_ON(call != trace_file->event_call); 1433 1434 if (trace_trigger_soft_disabled(trace_file)) 1435 return; 1436 1437 local_save_flags(fbuffer.flags); 1438 fbuffer.pc = preempt_count(); 1439 fbuffer.trace_file = trace_file; 1440 1441 dsize = __get_data_size(&tk->tp, regs); 1442 fbuffer.event = 1443 trace_event_buffer_lock_reserve(&fbuffer.buffer, trace_file, 1444 call->event.type, 1445 sizeof(*entry) + tk->tp.size + dsize, 1446 fbuffer.flags, fbuffer.pc); 1447 if (!fbuffer.event) 1448 return; 1449 1450 fbuffer.regs = regs; 1451 entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event); 1452 entry->func = (unsigned long)tk->rp.kp.addr; 1453 entry->ret_ip = (unsigned long)ri->ret_addr; 1454 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); 1455 1456 trace_event_buffer_commit(&fbuffer); 1457 } 1458 1459 static void 1460 kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, 1461 struct pt_regs *regs) 1462 { 1463 struct event_file_link *link; 1464 1465 trace_probe_for_each_link_rcu(link, &tk->tp) 1466 __kretprobe_trace_func(tk, ri, regs, link->file); 1467 } 1468 NOKPROBE_SYMBOL(kretprobe_trace_func); 1469 1470 /* Event entry printers */ 1471 static enum print_line_t 1472 print_kprobe_event(struct trace_iterator *iter, int flags, 1473 struct trace_event *event) 1474 { 1475 struct kprobe_trace_entry_head *field; 1476 struct trace_seq *s = &iter->seq; 1477 struct trace_probe *tp; 1478 1479 field = (struct kprobe_trace_entry_head *)iter->ent; 1480 tp = trace_probe_primary_from_call( 1481 container_of(event, struct trace_event_call, event)); 1482 if (WARN_ON_ONCE(!tp)) 1483 goto out; 1484 1485 trace_seq_printf(s, "%s: (", trace_probe_name(tp)); 1486 1487 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) 1488 goto out; 1489 1490 trace_seq_putc(s, ')'); 1491 1492 if (print_probe_args(s, tp->args, tp->nr_args, 1493 (u8 *)&field[1], field) < 0) 1494 goto out; 1495 1496 trace_seq_putc(s, '\n'); 1497 out: 1498 return trace_handle_return(s); 1499 } 1500 1501 static enum print_line_t 1502 print_kretprobe_event(struct trace_iterator *iter, int flags, 1503 struct trace_event *event) 1504 { 1505 struct kretprobe_trace_entry_head *field; 1506 struct trace_seq *s = &iter->seq; 1507 struct trace_probe *tp; 1508 1509 field = (struct kretprobe_trace_entry_head *)iter->ent; 1510 tp = trace_probe_primary_from_call( 1511 container_of(event, struct trace_event_call, event)); 1512 if (WARN_ON_ONCE(!tp)) 1513 goto out; 1514 1515 trace_seq_printf(s, "%s: (", trace_probe_name(tp)); 1516 1517 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) 1518 goto out; 1519 1520 trace_seq_puts(s, " <- "); 1521 1522 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) 1523 goto out; 1524 1525 trace_seq_putc(s, ')'); 1526 1527 if (print_probe_args(s, tp->args, tp->nr_args, 1528 (u8 *)&field[1], field) < 0) 1529 goto out; 1530 1531 trace_seq_putc(s, '\n'); 1532 1533 out: 1534 return trace_handle_return(s); 1535 } 1536 1537 1538 static int kprobe_event_define_fields(struct trace_event_call *event_call) 1539 { 1540 int ret; 1541 struct kprobe_trace_entry_head field; 1542 struct trace_probe *tp; 1543 1544 tp = trace_probe_primary_from_call(event_call); 1545 if (WARN_ON_ONCE(!tp)) 1546 return -ENOENT; 1547 1548 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); 1549 1550 return traceprobe_define_arg_fields(event_call, sizeof(field), tp); 1551 } 1552 1553 static int kretprobe_event_define_fields(struct trace_event_call *event_call) 1554 { 1555 int ret; 1556 struct kretprobe_trace_entry_head field; 1557 struct trace_probe *tp; 1558 1559 tp = trace_probe_primary_from_call(event_call); 1560 if (WARN_ON_ONCE(!tp)) 1561 return -ENOENT; 1562 1563 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); 1564 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); 1565 1566 return traceprobe_define_arg_fields(event_call, sizeof(field), tp); 1567 } 1568 1569 #ifdef CONFIG_PERF_EVENTS 1570 1571 /* Kprobe profile handler */ 1572 static int 1573 kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) 1574 { 1575 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1576 struct kprobe_trace_entry_head *entry; 1577 struct hlist_head *head; 1578 int size, __size, dsize; 1579 int rctx; 1580 1581 if (bpf_prog_array_valid(call)) { 1582 unsigned long orig_ip = instruction_pointer(regs); 1583 int ret; 1584 1585 ret = trace_call_bpf(call, regs); 1586 1587 /* 1588 * We need to check and see if we modified the pc of the 1589 * pt_regs, and if so return 1 so that we don't do the 1590 * single stepping. 1591 */ 1592 if (orig_ip != instruction_pointer(regs)) 1593 return 1; 1594 if (!ret) 1595 return 0; 1596 } 1597 1598 head = this_cpu_ptr(call->perf_events); 1599 if (hlist_empty(head)) 1600 return 0; 1601 1602 dsize = __get_data_size(&tk->tp, regs); 1603 __size = sizeof(*entry) + tk->tp.size + dsize; 1604 size = ALIGN(__size + sizeof(u32), sizeof(u64)); 1605 size -= sizeof(u32); 1606 1607 entry = perf_trace_buf_alloc(size, NULL, &rctx); 1608 if (!entry) 1609 return 0; 1610 1611 entry->ip = (unsigned long)tk->rp.kp.addr; 1612 memset(&entry[1], 0, dsize); 1613 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); 1614 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, 1615 head, NULL); 1616 return 0; 1617 } 1618 NOKPROBE_SYMBOL(kprobe_perf_func); 1619 1620 /* Kretprobe profile handler */ 1621 static void 1622 kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, 1623 struct pt_regs *regs) 1624 { 1625 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1626 struct kretprobe_trace_entry_head *entry; 1627 struct hlist_head *head; 1628 int size, __size, dsize; 1629 int rctx; 1630 1631 if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs)) 1632 return; 1633 1634 head = this_cpu_ptr(call->perf_events); 1635 if (hlist_empty(head)) 1636 return; 1637 1638 dsize = __get_data_size(&tk->tp, regs); 1639 __size = sizeof(*entry) + tk->tp.size + dsize; 1640 size = ALIGN(__size + sizeof(u32), sizeof(u64)); 1641 size -= sizeof(u32); 1642 1643 entry = perf_trace_buf_alloc(size, NULL, &rctx); 1644 if (!entry) 1645 return; 1646 1647 entry->func = (unsigned long)tk->rp.kp.addr; 1648 entry->ret_ip = (unsigned long)ri->ret_addr; 1649 store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize); 1650 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, 1651 head, NULL); 1652 } 1653 NOKPROBE_SYMBOL(kretprobe_perf_func); 1654 1655 int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type, 1656 const char **symbol, u64 *probe_offset, 1657 u64 *probe_addr, bool perf_type_tracepoint) 1658 { 1659 const char *pevent = trace_event_name(event->tp_event); 1660 const char *group = event->tp_event->class->system; 1661 struct trace_kprobe *tk; 1662 1663 if (perf_type_tracepoint) 1664 tk = find_trace_kprobe(pevent, group); 1665 else 1666 tk = trace_kprobe_primary_from_call(event->tp_event); 1667 if (!tk) 1668 return -EINVAL; 1669 1670 *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE 1671 : BPF_FD_TYPE_KPROBE; 1672 if (tk->symbol) { 1673 *symbol = tk->symbol; 1674 *probe_offset = tk->rp.kp.offset; 1675 *probe_addr = 0; 1676 } else { 1677 *symbol = NULL; 1678 *probe_offset = 0; 1679 *probe_addr = (unsigned long)tk->rp.kp.addr; 1680 } 1681 return 0; 1682 } 1683 #endif /* CONFIG_PERF_EVENTS */ 1684 1685 /* 1686 * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. 1687 * 1688 * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe 1689 * lockless, but we can't race with this __init function. 1690 */ 1691 static int kprobe_register(struct trace_event_call *event, 1692 enum trace_reg type, void *data) 1693 { 1694 struct trace_event_file *file = data; 1695 1696 switch (type) { 1697 case TRACE_REG_REGISTER: 1698 return enable_trace_kprobe(event, file); 1699 case TRACE_REG_UNREGISTER: 1700 return disable_trace_kprobe(event, file); 1701 1702 #ifdef CONFIG_PERF_EVENTS 1703 case TRACE_REG_PERF_REGISTER: 1704 return enable_trace_kprobe(event, NULL); 1705 case TRACE_REG_PERF_UNREGISTER: 1706 return disable_trace_kprobe(event, NULL); 1707 case TRACE_REG_PERF_OPEN: 1708 case TRACE_REG_PERF_CLOSE: 1709 case TRACE_REG_PERF_ADD: 1710 case TRACE_REG_PERF_DEL: 1711 return 0; 1712 #endif 1713 } 1714 return 0; 1715 } 1716 1717 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) 1718 { 1719 struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); 1720 int ret = 0; 1721 1722 raw_cpu_inc(*tk->nhit); 1723 1724 if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) 1725 kprobe_trace_func(tk, regs); 1726 #ifdef CONFIG_PERF_EVENTS 1727 if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) 1728 ret = kprobe_perf_func(tk, regs); 1729 #endif 1730 return ret; 1731 } 1732 NOKPROBE_SYMBOL(kprobe_dispatcher); 1733 1734 static int 1735 kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) 1736 { 1737 struct kretprobe *rp = get_kretprobe(ri); 1738 struct trace_kprobe *tk = container_of(rp, struct trace_kprobe, rp); 1739 1740 raw_cpu_inc(*tk->nhit); 1741 1742 if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) 1743 kretprobe_trace_func(tk, ri, regs); 1744 #ifdef CONFIG_PERF_EVENTS 1745 if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) 1746 kretprobe_perf_func(tk, ri, regs); 1747 #endif 1748 return 0; /* We don't tweek kernel, so just return 0 */ 1749 } 1750 NOKPROBE_SYMBOL(kretprobe_dispatcher); 1751 1752 static struct trace_event_functions kretprobe_funcs = { 1753 .trace = print_kretprobe_event 1754 }; 1755 1756 static struct trace_event_functions kprobe_funcs = { 1757 .trace = print_kprobe_event 1758 }; 1759 1760 static struct trace_event_fields kretprobe_fields_array[] = { 1761 { .type = TRACE_FUNCTION_TYPE, 1762 .define_fields = kretprobe_event_define_fields }, 1763 {} 1764 }; 1765 1766 static struct trace_event_fields kprobe_fields_array[] = { 1767 { .type = TRACE_FUNCTION_TYPE, 1768 .define_fields = kprobe_event_define_fields }, 1769 {} 1770 }; 1771 1772 static inline void init_trace_event_call(struct trace_kprobe *tk) 1773 { 1774 struct trace_event_call *call = trace_probe_event_call(&tk->tp); 1775 1776 if (trace_kprobe_is_return(tk)) { 1777 call->event.funcs = &kretprobe_funcs; 1778 call->class->fields_array = kretprobe_fields_array; 1779 } else { 1780 call->event.funcs = &kprobe_funcs; 1781 call->class->fields_array = kprobe_fields_array; 1782 } 1783 1784 call->flags = TRACE_EVENT_FL_KPROBE; 1785 call->class->reg = kprobe_register; 1786 } 1787 1788 static int register_kprobe_event(struct trace_kprobe *tk) 1789 { 1790 init_trace_event_call(tk); 1791 1792 return trace_probe_register_event_call(&tk->tp); 1793 } 1794 1795 static int unregister_kprobe_event(struct trace_kprobe *tk) 1796 { 1797 return trace_probe_unregister_event_call(&tk->tp); 1798 } 1799 1800 #ifdef CONFIG_PERF_EVENTS 1801 /* create a trace_kprobe, but don't add it to global lists */ 1802 struct trace_event_call * 1803 create_local_trace_kprobe(char *func, void *addr, unsigned long offs, 1804 bool is_return) 1805 { 1806 struct trace_kprobe *tk; 1807 int ret; 1808 char *event; 1809 1810 /* 1811 * local trace_kprobes are not added to dyn_event, so they are never 1812 * searched in find_trace_kprobe(). Therefore, there is no concern of 1813 * duplicated name here. 1814 */ 1815 event = func ? func : "DUMMY_EVENT"; 1816 1817 tk = alloc_trace_kprobe(KPROBE_EVENT_SYSTEM, event, (void *)addr, func, 1818 offs, 0 /* maxactive */, 0 /* nargs */, 1819 is_return); 1820 1821 if (IS_ERR(tk)) { 1822 pr_info("Failed to allocate trace_probe.(%d)\n", 1823 (int)PTR_ERR(tk)); 1824 return ERR_CAST(tk); 1825 } 1826 1827 init_trace_event_call(tk); 1828 1829 if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) { 1830 ret = -ENOMEM; 1831 goto error; 1832 } 1833 1834 ret = __register_trace_kprobe(tk); 1835 if (ret < 0) 1836 goto error; 1837 1838 return trace_probe_event_call(&tk->tp); 1839 error: 1840 free_trace_kprobe(tk); 1841 return ERR_PTR(ret); 1842 } 1843 1844 void destroy_local_trace_kprobe(struct trace_event_call *event_call) 1845 { 1846 struct trace_kprobe *tk; 1847 1848 tk = trace_kprobe_primary_from_call(event_call); 1849 if (unlikely(!tk)) 1850 return; 1851 1852 if (trace_probe_is_enabled(&tk->tp)) { 1853 WARN_ON(1); 1854 return; 1855 } 1856 1857 __unregister_trace_kprobe(tk); 1858 1859 free_trace_kprobe(tk); 1860 } 1861 #endif /* CONFIG_PERF_EVENTS */ 1862 1863 static __init void enable_boot_kprobe_events(void) 1864 { 1865 struct trace_array *tr = top_trace_array(); 1866 struct trace_event_file *file; 1867 struct trace_kprobe *tk; 1868 struct dyn_event *pos; 1869 1870 mutex_lock(&event_mutex); 1871 for_each_trace_kprobe(tk, pos) { 1872 list_for_each_entry(file, &tr->events, list) 1873 if (file->event_call == trace_probe_event_call(&tk->tp)) 1874 trace_event_enable_disable(file, 1, 0); 1875 } 1876 mutex_unlock(&event_mutex); 1877 } 1878 1879 static __init void setup_boot_kprobe_events(void) 1880 { 1881 char *p, *cmd = kprobe_boot_events_buf; 1882 int ret; 1883 1884 strreplace(kprobe_boot_events_buf, ',', ' '); 1885 1886 while (cmd && *cmd != '\0') { 1887 p = strchr(cmd, ';'); 1888 if (p) 1889 *p++ = '\0'; 1890 1891 ret = trace_run_command(cmd, create_or_delete_trace_kprobe); 1892 if (ret) 1893 pr_warn("Failed to add event(%d): %s\n", ret, cmd); 1894 1895 cmd = p; 1896 } 1897 1898 enable_boot_kprobe_events(); 1899 } 1900 1901 /* 1902 * Register dynevent at core_initcall. This allows kernel to setup kprobe 1903 * events in postcore_initcall without tracefs. 1904 */ 1905 static __init int init_kprobe_trace_early(void) 1906 { 1907 int ret; 1908 1909 ret = dyn_event_register(&trace_kprobe_ops); 1910 if (ret) 1911 return ret; 1912 1913 if (register_module_notifier(&trace_kprobe_module_nb)) 1914 return -EINVAL; 1915 1916 return 0; 1917 } 1918 core_initcall(init_kprobe_trace_early); 1919 1920 /* Make a tracefs interface for controlling probe points */ 1921 static __init int init_kprobe_trace(void) 1922 { 1923 int ret; 1924 struct dentry *entry; 1925 1926 ret = tracing_init_dentry(); 1927 if (ret) 1928 return 0; 1929 1930 entry = tracefs_create_file("kprobe_events", 0644, NULL, 1931 NULL, &kprobe_events_ops); 1932 1933 /* Event list interface */ 1934 if (!entry) 1935 pr_warn("Could not create tracefs 'kprobe_events' entry\n"); 1936 1937 /* Profile interface */ 1938 entry = tracefs_create_file("kprobe_profile", 0444, NULL, 1939 NULL, &kprobe_profile_ops); 1940 1941 if (!entry) 1942 pr_warn("Could not create tracefs 'kprobe_profile' entry\n"); 1943 1944 setup_boot_kprobe_events(); 1945 1946 return 0; 1947 } 1948 fs_initcall(init_kprobe_trace); 1949 1950 1951 #ifdef CONFIG_FTRACE_STARTUP_TEST 1952 static __init struct trace_event_file * 1953 find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) 1954 { 1955 struct trace_event_file *file; 1956 1957 list_for_each_entry(file, &tr->events, list) 1958 if (file->event_call == trace_probe_event_call(&tk->tp)) 1959 return file; 1960 1961 return NULL; 1962 } 1963 1964 /* 1965 * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this 1966 * stage, we can do this lockless. 1967 */ 1968 static __init int kprobe_trace_self_tests_init(void) 1969 { 1970 int ret, warn = 0; 1971 int (*target)(int, int, int, int, int, int); 1972 struct trace_kprobe *tk; 1973 struct trace_event_file *file; 1974 1975 if (tracing_is_disabled()) 1976 return -ENODEV; 1977 1978 if (tracing_selftest_disabled) 1979 return 0; 1980 1981 target = kprobe_trace_selftest_target; 1982 1983 pr_info("Testing kprobe tracing: "); 1984 1985 ret = trace_run_command("p:testprobe kprobe_trace_selftest_target $stack $stack0 +0($stack)", 1986 create_or_delete_trace_kprobe); 1987 if (WARN_ON_ONCE(ret)) { 1988 pr_warn("error on probing function entry.\n"); 1989 warn++; 1990 } else { 1991 /* Enable trace point */ 1992 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); 1993 if (WARN_ON_ONCE(tk == NULL)) { 1994 pr_warn("error on getting new probe.\n"); 1995 warn++; 1996 } else { 1997 file = find_trace_probe_file(tk, top_trace_array()); 1998 if (WARN_ON_ONCE(file == NULL)) { 1999 pr_warn("error on getting probe file.\n"); 2000 warn++; 2001 } else 2002 enable_trace_kprobe( 2003 trace_probe_event_call(&tk->tp), file); 2004 } 2005 } 2006 2007 ret = trace_run_command("r:testprobe2 kprobe_trace_selftest_target $retval", 2008 create_or_delete_trace_kprobe); 2009 if (WARN_ON_ONCE(ret)) { 2010 pr_warn("error on probing function return.\n"); 2011 warn++; 2012 } else { 2013 /* Enable trace point */ 2014 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); 2015 if (WARN_ON_ONCE(tk == NULL)) { 2016 pr_warn("error on getting 2nd new probe.\n"); 2017 warn++; 2018 } else { 2019 file = find_trace_probe_file(tk, top_trace_array()); 2020 if (WARN_ON_ONCE(file == NULL)) { 2021 pr_warn("error on getting probe file.\n"); 2022 warn++; 2023 } else 2024 enable_trace_kprobe( 2025 trace_probe_event_call(&tk->tp), file); 2026 } 2027 } 2028 2029 if (warn) 2030 goto end; 2031 2032 ret = target(1, 2, 3, 4, 5, 6); 2033 2034 /* 2035 * Not expecting an error here, the check is only to prevent the 2036 * optimizer from removing the call to target() as otherwise there 2037 * are no side-effects and the call is never performed. 2038 */ 2039 if (ret != 21) 2040 warn++; 2041 2042 /* Disable trace points before removing it */ 2043 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); 2044 if (WARN_ON_ONCE(tk == NULL)) { 2045 pr_warn("error on getting test probe.\n"); 2046 warn++; 2047 } else { 2048 if (trace_kprobe_nhit(tk) != 1) { 2049 pr_warn("incorrect number of testprobe hits\n"); 2050 warn++; 2051 } 2052 2053 file = find_trace_probe_file(tk, top_trace_array()); 2054 if (WARN_ON_ONCE(file == NULL)) { 2055 pr_warn("error on getting probe file.\n"); 2056 warn++; 2057 } else 2058 disable_trace_kprobe( 2059 trace_probe_event_call(&tk->tp), file); 2060 } 2061 2062 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); 2063 if (WARN_ON_ONCE(tk == NULL)) { 2064 pr_warn("error on getting 2nd test probe.\n"); 2065 warn++; 2066 } else { 2067 if (trace_kprobe_nhit(tk) != 1) { 2068 pr_warn("incorrect number of testprobe2 hits\n"); 2069 warn++; 2070 } 2071 2072 file = find_trace_probe_file(tk, top_trace_array()); 2073 if (WARN_ON_ONCE(file == NULL)) { 2074 pr_warn("error on getting probe file.\n"); 2075 warn++; 2076 } else 2077 disable_trace_kprobe( 2078 trace_probe_event_call(&tk->tp), file); 2079 } 2080 2081 ret = trace_run_command("-:testprobe", create_or_delete_trace_kprobe); 2082 if (WARN_ON_ONCE(ret)) { 2083 pr_warn("error on deleting a probe.\n"); 2084 warn++; 2085 } 2086 2087 ret = trace_run_command("-:testprobe2", create_or_delete_trace_kprobe); 2088 if (WARN_ON_ONCE(ret)) { 2089 pr_warn("error on deleting a probe.\n"); 2090 warn++; 2091 } 2092 2093 end: 2094 ret = dyn_events_release_all(&trace_kprobe_ops); 2095 if (WARN_ON_ONCE(ret)) { 2096 pr_warn("error on cleaning up probes.\n"); 2097 warn++; 2098 } 2099 /* 2100 * Wait for the optimizer work to finish. Otherwise it might fiddle 2101 * with probes in already freed __init text. 2102 */ 2103 wait_for_kprobe_optimizer(); 2104 if (warn) 2105 pr_cont("NG: Some tests are failed. Please check them.\n"); 2106 else 2107 pr_cont("OK\n"); 2108 return 0; 2109 } 2110 2111 late_initcall(kprobe_trace_self_tests_init); 2112 2113 #endif 2114