1 /* 2 * Kprobes-based tracing events 3 * 4 * Created by Masami Hiramatsu <mhiramat@redhat.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 */ 19 20 #include <linux/module.h> 21 #include <linux/uaccess.h> 22 23 #include "trace_probe.h" 24 25 #define KPROBE_EVENT_SYSTEM "kprobes" 26 27 /** 28 * Kprobe event core functions 29 */ 30 struct trace_kprobe { 31 struct list_head list; 32 struct kretprobe rp; /* Use rp.kp for kprobe use */ 33 unsigned long __percpu *nhit; 34 const char *symbol; /* symbol name */ 35 struct trace_probe tp; 36 }; 37 38 #define SIZEOF_TRACE_KPROBE(n) \ 39 (offsetof(struct trace_kprobe, tp.args) + \ 40 (sizeof(struct probe_arg) * (n))) 41 42 43 static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk) 44 { 45 return tk->rp.handler != NULL; 46 } 47 48 static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk) 49 { 50 return tk->symbol ? tk->symbol : "unknown"; 51 } 52 53 static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk) 54 { 55 return tk->rp.kp.offset; 56 } 57 58 static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) 59 { 60 return !!(kprobe_gone(&tk->rp.kp)); 61 } 62 63 static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, 64 struct module *mod) 65 { 66 int len = strlen(mod->name); 67 const char *name = trace_kprobe_symbol(tk); 68 return strncmp(mod->name, name, len) == 0 && name[len] == ':'; 69 } 70 71 static nokprobe_inline bool trace_kprobe_is_on_module(struct trace_kprobe *tk) 72 { 73 return !!strchr(trace_kprobe_symbol(tk), ':'); 74 } 75 76 static int register_kprobe_event(struct trace_kprobe *tk); 77 static int unregister_kprobe_event(struct trace_kprobe *tk); 78 79 static DEFINE_MUTEX(probe_lock); 80 static LIST_HEAD(probe_list); 81 82 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); 83 static int kretprobe_dispatcher(struct kretprobe_instance *ri, 84 struct pt_regs *regs); 85 86 /* Memory fetching by symbol */ 87 struct symbol_cache { 88 char *symbol; 89 long offset; 90 unsigned long addr; 91 }; 92 93 unsigned long update_symbol_cache(struct symbol_cache *sc) 94 { 95 sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol); 96 97 if (sc->addr) 98 sc->addr += sc->offset; 99 100 return sc->addr; 101 } 102 103 void free_symbol_cache(struct symbol_cache *sc) 104 { 105 kfree(sc->symbol); 106 kfree(sc); 107 } 108 109 struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) 110 { 111 struct symbol_cache *sc; 112 113 if (!sym || strlen(sym) == 0) 114 return NULL; 115 116 sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL); 117 if (!sc) 118 return NULL; 119 120 sc->symbol = kstrdup(sym, GFP_KERNEL); 121 if (!sc->symbol) { 122 kfree(sc); 123 return NULL; 124 } 125 sc->offset = offset; 126 update_symbol_cache(sc); 127 128 return sc; 129 } 130 131 /* 132 * Kprobes-specific fetch functions 133 */ 134 #define DEFINE_FETCH_stack(type) \ 135 static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \ 136 void *offset, void *dest) \ 137 { \ 138 *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ 139 (unsigned int)((unsigned long)offset)); \ 140 } \ 141 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(stack, type)); 142 143 DEFINE_BASIC_FETCH_FUNCS(stack) 144 /* No string on the stack entry */ 145 #define fetch_stack_string NULL 146 #define fetch_stack_string_size NULL 147 148 #define DEFINE_FETCH_memory(type) \ 149 static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \ 150 void *addr, void *dest) \ 151 { \ 152 type retval; \ 153 if (probe_kernel_address(addr, retval)) \ 154 *(type *)dest = 0; \ 155 else \ 156 *(type *)dest = retval; \ 157 } \ 158 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, type)); 159 160 DEFINE_BASIC_FETCH_FUNCS(memory) 161 /* 162 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max 163 * length and relative data location. 164 */ 165 static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, 166 void *addr, void *dest) 167 { 168 int maxlen = get_rloc_len(*(u32 *)dest); 169 u8 *dst = get_rloc_data(dest); 170 long ret; 171 172 if (!maxlen) 173 return; 174 175 /* 176 * Try to get string again, since the string can be changed while 177 * probing. 178 */ 179 ret = strncpy_from_unsafe(dst, addr, maxlen); 180 181 if (ret < 0) { /* Failed to fetch string */ 182 dst[0] = '\0'; 183 *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); 184 } else { 185 *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest)); 186 } 187 } 188 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string)); 189 190 /* Return the length of string -- including null terminal byte */ 191 static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, 192 void *addr, void *dest) 193 { 194 mm_segment_t old_fs; 195 int ret, len = 0; 196 u8 c; 197 198 old_fs = get_fs(); 199 set_fs(KERNEL_DS); 200 pagefault_disable(); 201 202 do { 203 ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); 204 len++; 205 } while (c && ret == 0 && len < MAX_STRING_SIZE); 206 207 pagefault_enable(); 208 set_fs(old_fs); 209 210 if (ret < 0) /* Failed to check the length */ 211 *(u32 *)dest = 0; 212 else 213 *(u32 *)dest = len; 214 } 215 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string_size)); 216 217 #define DEFINE_FETCH_symbol(type) \ 218 void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, void *data, void *dest)\ 219 { \ 220 struct symbol_cache *sc = data; \ 221 if (sc->addr) \ 222 fetch_memory_##type(regs, (void *)sc->addr, dest); \ 223 else \ 224 *(type *)dest = 0; \ 225 } \ 226 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(symbol, type)); 227 228 DEFINE_BASIC_FETCH_FUNCS(symbol) 229 DEFINE_FETCH_symbol(string) 230 DEFINE_FETCH_symbol(string_size) 231 232 /* kprobes don't support file_offset fetch methods */ 233 #define fetch_file_offset_u8 NULL 234 #define fetch_file_offset_u16 NULL 235 #define fetch_file_offset_u32 NULL 236 #define fetch_file_offset_u64 NULL 237 #define fetch_file_offset_string NULL 238 #define fetch_file_offset_string_size NULL 239 240 /* Fetch type information table */ 241 static const struct fetch_type kprobes_fetch_type_table[] = { 242 /* Special types */ 243 [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, 244 sizeof(u32), 1, "__data_loc char[]"), 245 [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, 246 string_size, sizeof(u32), 0, "u32"), 247 /* Basic types */ 248 ASSIGN_FETCH_TYPE(u8, u8, 0), 249 ASSIGN_FETCH_TYPE(u16, u16, 0), 250 ASSIGN_FETCH_TYPE(u32, u32, 0), 251 ASSIGN_FETCH_TYPE(u64, u64, 0), 252 ASSIGN_FETCH_TYPE(s8, u8, 1), 253 ASSIGN_FETCH_TYPE(s16, u16, 1), 254 ASSIGN_FETCH_TYPE(s32, u32, 1), 255 ASSIGN_FETCH_TYPE(s64, u64, 1), 256 257 ASSIGN_FETCH_TYPE_END 258 }; 259 260 /* 261 * Allocate new trace_probe and initialize it (including kprobes). 262 */ 263 static struct trace_kprobe *alloc_trace_kprobe(const char *group, 264 const char *event, 265 void *addr, 266 const char *symbol, 267 unsigned long offs, 268 int nargs, bool is_return) 269 { 270 struct trace_kprobe *tk; 271 int ret = -ENOMEM; 272 273 tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL); 274 if (!tk) 275 return ERR_PTR(ret); 276 277 tk->nhit = alloc_percpu(unsigned long); 278 if (!tk->nhit) 279 goto error; 280 281 if (symbol) { 282 tk->symbol = kstrdup(symbol, GFP_KERNEL); 283 if (!tk->symbol) 284 goto error; 285 tk->rp.kp.symbol_name = tk->symbol; 286 tk->rp.kp.offset = offs; 287 } else 288 tk->rp.kp.addr = addr; 289 290 if (is_return) 291 tk->rp.handler = kretprobe_dispatcher; 292 else 293 tk->rp.kp.pre_handler = kprobe_dispatcher; 294 295 if (!event || !is_good_name(event)) { 296 ret = -EINVAL; 297 goto error; 298 } 299 300 tk->tp.call.class = &tk->tp.class; 301 tk->tp.call.name = kstrdup(event, GFP_KERNEL); 302 if (!tk->tp.call.name) 303 goto error; 304 305 if (!group || !is_good_name(group)) { 306 ret = -EINVAL; 307 goto error; 308 } 309 310 tk->tp.class.system = kstrdup(group, GFP_KERNEL); 311 if (!tk->tp.class.system) 312 goto error; 313 314 INIT_LIST_HEAD(&tk->list); 315 INIT_LIST_HEAD(&tk->tp.files); 316 return tk; 317 error: 318 kfree(tk->tp.call.name); 319 kfree(tk->symbol); 320 free_percpu(tk->nhit); 321 kfree(tk); 322 return ERR_PTR(ret); 323 } 324 325 static void free_trace_kprobe(struct trace_kprobe *tk) 326 { 327 int i; 328 329 for (i = 0; i < tk->tp.nr_args; i++) 330 traceprobe_free_probe_arg(&tk->tp.args[i]); 331 332 kfree(tk->tp.call.class->system); 333 kfree(tk->tp.call.name); 334 kfree(tk->symbol); 335 free_percpu(tk->nhit); 336 kfree(tk); 337 } 338 339 static struct trace_kprobe *find_trace_kprobe(const char *event, 340 const char *group) 341 { 342 struct trace_kprobe *tk; 343 344 list_for_each_entry(tk, &probe_list, list) 345 if (strcmp(trace_event_name(&tk->tp.call), event) == 0 && 346 strcmp(tk->tp.call.class->system, group) == 0) 347 return tk; 348 return NULL; 349 } 350 351 /* 352 * Enable trace_probe 353 * if the file is NULL, enable "perf" handler, or enable "trace" handler. 354 */ 355 static int 356 enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) 357 { 358 int ret = 0; 359 360 if (file) { 361 struct event_file_link *link; 362 363 link = kmalloc(sizeof(*link), GFP_KERNEL); 364 if (!link) { 365 ret = -ENOMEM; 366 goto out; 367 } 368 369 link->file = file; 370 list_add_tail_rcu(&link->list, &tk->tp.files); 371 372 tk->tp.flags |= TP_FLAG_TRACE; 373 } else 374 tk->tp.flags |= TP_FLAG_PROFILE; 375 376 if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) { 377 if (trace_kprobe_is_return(tk)) 378 ret = enable_kretprobe(&tk->rp); 379 else 380 ret = enable_kprobe(&tk->rp.kp); 381 } 382 out: 383 return ret; 384 } 385 386 /* 387 * Disable trace_probe 388 * if the file is NULL, disable "perf" handler, or disable "trace" handler. 389 */ 390 static int 391 disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) 392 { 393 struct event_file_link *link = NULL; 394 int wait = 0; 395 int ret = 0; 396 397 if (file) { 398 link = find_event_file_link(&tk->tp, file); 399 if (!link) { 400 ret = -EINVAL; 401 goto out; 402 } 403 404 list_del_rcu(&link->list); 405 wait = 1; 406 if (!list_empty(&tk->tp.files)) 407 goto out; 408 409 tk->tp.flags &= ~TP_FLAG_TRACE; 410 } else 411 tk->tp.flags &= ~TP_FLAG_PROFILE; 412 413 if (!trace_probe_is_enabled(&tk->tp) && trace_probe_is_registered(&tk->tp)) { 414 if (trace_kprobe_is_return(tk)) 415 disable_kretprobe(&tk->rp); 416 else 417 disable_kprobe(&tk->rp.kp); 418 wait = 1; 419 } 420 out: 421 if (wait) { 422 /* 423 * Synchronize with kprobe_trace_func/kretprobe_trace_func 424 * to ensure disabled (all running handlers are finished). 425 * This is not only for kfree(), but also the caller, 426 * trace_remove_event_call() supposes it for releasing 427 * event_call related objects, which will be accessed in 428 * the kprobe_trace_func/kretprobe_trace_func. 429 */ 430 synchronize_sched(); 431 kfree(link); /* Ignored if link == NULL */ 432 } 433 434 return ret; 435 } 436 437 /* Internal register function - just handle k*probes and flags */ 438 static int __register_trace_kprobe(struct trace_kprobe *tk) 439 { 440 int i, ret; 441 442 if (trace_probe_is_registered(&tk->tp)) 443 return -EINVAL; 444 445 for (i = 0; i < tk->tp.nr_args; i++) 446 traceprobe_update_arg(&tk->tp.args[i]); 447 448 /* Set/clear disabled flag according to tp->flag */ 449 if (trace_probe_is_enabled(&tk->tp)) 450 tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; 451 else 452 tk->rp.kp.flags |= KPROBE_FLAG_DISABLED; 453 454 if (trace_kprobe_is_return(tk)) 455 ret = register_kretprobe(&tk->rp); 456 else 457 ret = register_kprobe(&tk->rp.kp); 458 459 if (ret == 0) 460 tk->tp.flags |= TP_FLAG_REGISTERED; 461 else { 462 pr_warning("Could not insert probe at %s+%lu: %d\n", 463 trace_kprobe_symbol(tk), trace_kprobe_offset(tk), ret); 464 if (ret == -ENOENT && trace_kprobe_is_on_module(tk)) { 465 pr_warning("This probe might be able to register after" 466 "target module is loaded. Continue.\n"); 467 ret = 0; 468 } else if (ret == -EILSEQ) { 469 pr_warning("Probing address(0x%p) is not an " 470 "instruction boundary.\n", 471 tk->rp.kp.addr); 472 ret = -EINVAL; 473 } 474 } 475 476 return ret; 477 } 478 479 /* Internal unregister function - just handle k*probes and flags */ 480 static void __unregister_trace_kprobe(struct trace_kprobe *tk) 481 { 482 if (trace_probe_is_registered(&tk->tp)) { 483 if (trace_kprobe_is_return(tk)) 484 unregister_kretprobe(&tk->rp); 485 else 486 unregister_kprobe(&tk->rp.kp); 487 tk->tp.flags &= ~TP_FLAG_REGISTERED; 488 /* Cleanup kprobe for reuse */ 489 if (tk->rp.kp.symbol_name) 490 tk->rp.kp.addr = NULL; 491 } 492 } 493 494 /* Unregister a trace_probe and probe_event: call with locking probe_lock */ 495 static int unregister_trace_kprobe(struct trace_kprobe *tk) 496 { 497 /* Enabled event can not be unregistered */ 498 if (trace_probe_is_enabled(&tk->tp)) 499 return -EBUSY; 500 501 /* Will fail if probe is being used by ftrace or perf */ 502 if (unregister_kprobe_event(tk)) 503 return -EBUSY; 504 505 __unregister_trace_kprobe(tk); 506 list_del(&tk->list); 507 508 return 0; 509 } 510 511 /* Register a trace_probe and probe_event */ 512 static int register_trace_kprobe(struct trace_kprobe *tk) 513 { 514 struct trace_kprobe *old_tk; 515 int ret; 516 517 mutex_lock(&probe_lock); 518 519 /* Delete old (same name) event if exist */ 520 old_tk = find_trace_kprobe(trace_event_name(&tk->tp.call), 521 tk->tp.call.class->system); 522 if (old_tk) { 523 ret = unregister_trace_kprobe(old_tk); 524 if (ret < 0) 525 goto end; 526 free_trace_kprobe(old_tk); 527 } 528 529 /* Register new event */ 530 ret = register_kprobe_event(tk); 531 if (ret) { 532 pr_warning("Failed to register probe event(%d)\n", ret); 533 goto end; 534 } 535 536 /* Register k*probe */ 537 ret = __register_trace_kprobe(tk); 538 if (ret < 0) 539 unregister_kprobe_event(tk); 540 else 541 list_add_tail(&tk->list, &probe_list); 542 543 end: 544 mutex_unlock(&probe_lock); 545 return ret; 546 } 547 548 /* Module notifier call back, checking event on the module */ 549 static int trace_kprobe_module_callback(struct notifier_block *nb, 550 unsigned long val, void *data) 551 { 552 struct module *mod = data; 553 struct trace_kprobe *tk; 554 int ret; 555 556 if (val != MODULE_STATE_COMING) 557 return NOTIFY_DONE; 558 559 /* Update probes on coming module */ 560 mutex_lock(&probe_lock); 561 list_for_each_entry(tk, &probe_list, list) { 562 if (trace_kprobe_within_module(tk, mod)) { 563 /* Don't need to check busy - this should have gone. */ 564 __unregister_trace_kprobe(tk); 565 ret = __register_trace_kprobe(tk); 566 if (ret) 567 pr_warning("Failed to re-register probe %s on" 568 "%s: %d\n", 569 trace_event_name(&tk->tp.call), 570 mod->name, ret); 571 } 572 } 573 mutex_unlock(&probe_lock); 574 575 return NOTIFY_DONE; 576 } 577 578 static struct notifier_block trace_kprobe_module_nb = { 579 .notifier_call = trace_kprobe_module_callback, 580 .priority = 1 /* Invoked after kprobe module callback */ 581 }; 582 583 static int create_trace_kprobe(int argc, char **argv) 584 { 585 /* 586 * Argument syntax: 587 * - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] 588 * - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS] 589 * Fetch args: 590 * $retval : fetch return value 591 * $stack : fetch stack address 592 * $stackN : fetch Nth of stack (N:0-) 593 * @ADDR : fetch memory at ADDR (ADDR should be in kernel) 594 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) 595 * %REG : fetch register REG 596 * Dereferencing memory fetch: 597 * +|-offs(ARG) : fetch memory at ARG +|- offs address. 598 * Alias name of args: 599 * NAME=FETCHARG : set NAME as alias of FETCHARG. 600 * Type of args: 601 * FETCHARG:TYPE : use TYPE instead of unsigned long. 602 */ 603 struct trace_kprobe *tk; 604 int i, ret = 0; 605 bool is_return = false, is_delete = false; 606 char *symbol = NULL, *event = NULL, *group = NULL; 607 char *arg; 608 unsigned long offset = 0; 609 void *addr = NULL; 610 char buf[MAX_EVENT_NAME_LEN]; 611 612 /* argc must be >= 1 */ 613 if (argv[0][0] == 'p') 614 is_return = false; 615 else if (argv[0][0] == 'r') 616 is_return = true; 617 else if (argv[0][0] == '-') 618 is_delete = true; 619 else { 620 pr_info("Probe definition must be started with 'p', 'r' or" 621 " '-'.\n"); 622 return -EINVAL; 623 } 624 625 if (argv[0][1] == ':') { 626 event = &argv[0][2]; 627 if (strchr(event, '/')) { 628 group = event; 629 event = strchr(group, '/') + 1; 630 event[-1] = '\0'; 631 if (strlen(group) == 0) { 632 pr_info("Group name is not specified\n"); 633 return -EINVAL; 634 } 635 } 636 if (strlen(event) == 0) { 637 pr_info("Event name is not specified\n"); 638 return -EINVAL; 639 } 640 } 641 if (!group) 642 group = KPROBE_EVENT_SYSTEM; 643 644 if (is_delete) { 645 if (!event) { 646 pr_info("Delete command needs an event name.\n"); 647 return -EINVAL; 648 } 649 mutex_lock(&probe_lock); 650 tk = find_trace_kprobe(event, group); 651 if (!tk) { 652 mutex_unlock(&probe_lock); 653 pr_info("Event %s/%s doesn't exist.\n", group, event); 654 return -ENOENT; 655 } 656 /* delete an event */ 657 ret = unregister_trace_kprobe(tk); 658 if (ret == 0) 659 free_trace_kprobe(tk); 660 mutex_unlock(&probe_lock); 661 return ret; 662 } 663 664 if (argc < 2) { 665 pr_info("Probe point is not specified.\n"); 666 return -EINVAL; 667 } 668 if (isdigit(argv[1][0])) { 669 if (is_return) { 670 pr_info("Return probe point must be a symbol.\n"); 671 return -EINVAL; 672 } 673 /* an address specified */ 674 ret = kstrtoul(&argv[1][0], 0, (unsigned long *)&addr); 675 if (ret) { 676 pr_info("Failed to parse address.\n"); 677 return ret; 678 } 679 } else { 680 /* a symbol specified */ 681 symbol = argv[1]; 682 /* TODO: support .init module functions */ 683 ret = traceprobe_split_symbol_offset(symbol, &offset); 684 if (ret) { 685 pr_info("Failed to parse symbol.\n"); 686 return ret; 687 } 688 if (offset && is_return) { 689 pr_info("Return probe must be used without offset.\n"); 690 return -EINVAL; 691 } 692 } 693 argc -= 2; argv += 2; 694 695 /* setup a probe */ 696 if (!event) { 697 /* Make a new event name */ 698 if (symbol) 699 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", 700 is_return ? 'r' : 'p', symbol, offset); 701 else 702 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", 703 is_return ? 'r' : 'p', addr); 704 event = buf; 705 } 706 tk = alloc_trace_kprobe(group, event, addr, symbol, offset, argc, 707 is_return); 708 if (IS_ERR(tk)) { 709 pr_info("Failed to allocate trace_probe.(%d)\n", 710 (int)PTR_ERR(tk)); 711 return PTR_ERR(tk); 712 } 713 714 /* parse arguments */ 715 ret = 0; 716 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { 717 struct probe_arg *parg = &tk->tp.args[i]; 718 719 /* Increment count for freeing args in error case */ 720 tk->tp.nr_args++; 721 722 /* Parse argument name */ 723 arg = strchr(argv[i], '='); 724 if (arg) { 725 *arg++ = '\0'; 726 parg->name = kstrdup(argv[i], GFP_KERNEL); 727 } else { 728 arg = argv[i]; 729 /* If argument name is omitted, set "argN" */ 730 snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); 731 parg->name = kstrdup(buf, GFP_KERNEL); 732 } 733 734 if (!parg->name) { 735 pr_info("Failed to allocate argument[%d] name.\n", i); 736 ret = -ENOMEM; 737 goto error; 738 } 739 740 if (!is_good_name(parg->name)) { 741 pr_info("Invalid argument[%d] name: %s\n", 742 i, parg->name); 743 ret = -EINVAL; 744 goto error; 745 } 746 747 if (traceprobe_conflict_field_name(parg->name, 748 tk->tp.args, i)) { 749 pr_info("Argument[%d] name '%s' conflicts with " 750 "another field.\n", i, argv[i]); 751 ret = -EINVAL; 752 goto error; 753 } 754 755 /* Parse fetch argument */ 756 ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg, 757 is_return, true, 758 kprobes_fetch_type_table); 759 if (ret) { 760 pr_info("Parse error at argument[%d]. (%d)\n", i, ret); 761 goto error; 762 } 763 } 764 765 ret = register_trace_kprobe(tk); 766 if (ret) 767 goto error; 768 return 0; 769 770 error: 771 free_trace_kprobe(tk); 772 return ret; 773 } 774 775 static int release_all_trace_kprobes(void) 776 { 777 struct trace_kprobe *tk; 778 int ret = 0; 779 780 mutex_lock(&probe_lock); 781 /* Ensure no probe is in use. */ 782 list_for_each_entry(tk, &probe_list, list) 783 if (trace_probe_is_enabled(&tk->tp)) { 784 ret = -EBUSY; 785 goto end; 786 } 787 /* TODO: Use batch unregistration */ 788 while (!list_empty(&probe_list)) { 789 tk = list_entry(probe_list.next, struct trace_kprobe, list); 790 ret = unregister_trace_kprobe(tk); 791 if (ret) 792 goto end; 793 free_trace_kprobe(tk); 794 } 795 796 end: 797 mutex_unlock(&probe_lock); 798 799 return ret; 800 } 801 802 /* Probes listing interfaces */ 803 static void *probes_seq_start(struct seq_file *m, loff_t *pos) 804 { 805 mutex_lock(&probe_lock); 806 return seq_list_start(&probe_list, *pos); 807 } 808 809 static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) 810 { 811 return seq_list_next(v, &probe_list, pos); 812 } 813 814 static void probes_seq_stop(struct seq_file *m, void *v) 815 { 816 mutex_unlock(&probe_lock); 817 } 818 819 static int probes_seq_show(struct seq_file *m, void *v) 820 { 821 struct trace_kprobe *tk = v; 822 int i; 823 824 seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p'); 825 seq_printf(m, ":%s/%s", tk->tp.call.class->system, 826 trace_event_name(&tk->tp.call)); 827 828 if (!tk->symbol) 829 seq_printf(m, " 0x%p", tk->rp.kp.addr); 830 else if (tk->rp.kp.offset) 831 seq_printf(m, " %s+%u", trace_kprobe_symbol(tk), 832 tk->rp.kp.offset); 833 else 834 seq_printf(m, " %s", trace_kprobe_symbol(tk)); 835 836 for (i = 0; i < tk->tp.nr_args; i++) 837 seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm); 838 seq_putc(m, '\n'); 839 840 return 0; 841 } 842 843 static const struct seq_operations probes_seq_op = { 844 .start = probes_seq_start, 845 .next = probes_seq_next, 846 .stop = probes_seq_stop, 847 .show = probes_seq_show 848 }; 849 850 static int probes_open(struct inode *inode, struct file *file) 851 { 852 int ret; 853 854 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { 855 ret = release_all_trace_kprobes(); 856 if (ret < 0) 857 return ret; 858 } 859 860 return seq_open(file, &probes_seq_op); 861 } 862 863 static ssize_t probes_write(struct file *file, const char __user *buffer, 864 size_t count, loff_t *ppos) 865 { 866 return traceprobe_probes_write(file, buffer, count, ppos, 867 create_trace_kprobe); 868 } 869 870 static const struct file_operations kprobe_events_ops = { 871 .owner = THIS_MODULE, 872 .open = probes_open, 873 .read = seq_read, 874 .llseek = seq_lseek, 875 .release = seq_release, 876 .write = probes_write, 877 }; 878 879 /* Probes profiling interfaces */ 880 static int probes_profile_seq_show(struct seq_file *m, void *v) 881 { 882 struct trace_kprobe *tk = v; 883 unsigned long nhit = 0; 884 int cpu; 885 886 for_each_possible_cpu(cpu) 887 nhit += *per_cpu_ptr(tk->nhit, cpu); 888 889 seq_printf(m, " %-44s %15lu %15lu\n", 890 trace_event_name(&tk->tp.call), nhit, 891 tk->rp.kp.nmissed); 892 893 return 0; 894 } 895 896 static const struct seq_operations profile_seq_op = { 897 .start = probes_seq_start, 898 .next = probes_seq_next, 899 .stop = probes_seq_stop, 900 .show = probes_profile_seq_show 901 }; 902 903 static int profile_open(struct inode *inode, struct file *file) 904 { 905 return seq_open(file, &profile_seq_op); 906 } 907 908 static const struct file_operations kprobe_profile_ops = { 909 .owner = THIS_MODULE, 910 .open = profile_open, 911 .read = seq_read, 912 .llseek = seq_lseek, 913 .release = seq_release, 914 }; 915 916 /* Kprobe handler */ 917 static nokprobe_inline void 918 __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, 919 struct trace_event_file *trace_file) 920 { 921 struct kprobe_trace_entry_head *entry; 922 struct ring_buffer_event *event; 923 struct ring_buffer *buffer; 924 int size, dsize, pc; 925 unsigned long irq_flags; 926 struct trace_event_call *call = &tk->tp.call; 927 928 WARN_ON(call != trace_file->event_call); 929 930 if (trace_trigger_soft_disabled(trace_file)) 931 return; 932 933 local_save_flags(irq_flags); 934 pc = preempt_count(); 935 936 dsize = __get_data_size(&tk->tp, regs); 937 size = sizeof(*entry) + tk->tp.size + dsize; 938 939 event = trace_event_buffer_lock_reserve(&buffer, trace_file, 940 call->event.type, 941 size, irq_flags, pc); 942 if (!event) 943 return; 944 945 entry = ring_buffer_event_data(event); 946 entry->ip = (unsigned long)tk->rp.kp.addr; 947 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); 948 949 event_trigger_unlock_commit_regs(trace_file, buffer, event, 950 entry, irq_flags, pc, regs); 951 } 952 953 static void 954 kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) 955 { 956 struct event_file_link *link; 957 958 list_for_each_entry_rcu(link, &tk->tp.files, list) 959 __kprobe_trace_func(tk, regs, link->file); 960 } 961 NOKPROBE_SYMBOL(kprobe_trace_func); 962 963 /* Kretprobe handler */ 964 static nokprobe_inline void 965 __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, 966 struct pt_regs *regs, 967 struct trace_event_file *trace_file) 968 { 969 struct kretprobe_trace_entry_head *entry; 970 struct ring_buffer_event *event; 971 struct ring_buffer *buffer; 972 int size, pc, dsize; 973 unsigned long irq_flags; 974 struct trace_event_call *call = &tk->tp.call; 975 976 WARN_ON(call != trace_file->event_call); 977 978 if (trace_trigger_soft_disabled(trace_file)) 979 return; 980 981 local_save_flags(irq_flags); 982 pc = preempt_count(); 983 984 dsize = __get_data_size(&tk->tp, regs); 985 size = sizeof(*entry) + tk->tp.size + dsize; 986 987 event = trace_event_buffer_lock_reserve(&buffer, trace_file, 988 call->event.type, 989 size, irq_flags, pc); 990 if (!event) 991 return; 992 993 entry = ring_buffer_event_data(event); 994 entry->func = (unsigned long)tk->rp.kp.addr; 995 entry->ret_ip = (unsigned long)ri->ret_addr; 996 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); 997 998 event_trigger_unlock_commit_regs(trace_file, buffer, event, 999 entry, irq_flags, pc, regs); 1000 } 1001 1002 static void 1003 kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, 1004 struct pt_regs *regs) 1005 { 1006 struct event_file_link *link; 1007 1008 list_for_each_entry_rcu(link, &tk->tp.files, list) 1009 __kretprobe_trace_func(tk, ri, regs, link->file); 1010 } 1011 NOKPROBE_SYMBOL(kretprobe_trace_func); 1012 1013 /* Event entry printers */ 1014 static enum print_line_t 1015 print_kprobe_event(struct trace_iterator *iter, int flags, 1016 struct trace_event *event) 1017 { 1018 struct kprobe_trace_entry_head *field; 1019 struct trace_seq *s = &iter->seq; 1020 struct trace_probe *tp; 1021 u8 *data; 1022 int i; 1023 1024 field = (struct kprobe_trace_entry_head *)iter->ent; 1025 tp = container_of(event, struct trace_probe, call.event); 1026 1027 trace_seq_printf(s, "%s: (", trace_event_name(&tp->call)); 1028 1029 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) 1030 goto out; 1031 1032 trace_seq_putc(s, ')'); 1033 1034 data = (u8 *)&field[1]; 1035 for (i = 0; i < tp->nr_args; i++) 1036 if (!tp->args[i].type->print(s, tp->args[i].name, 1037 data + tp->args[i].offset, field)) 1038 goto out; 1039 1040 trace_seq_putc(s, '\n'); 1041 out: 1042 return trace_handle_return(s); 1043 } 1044 1045 static enum print_line_t 1046 print_kretprobe_event(struct trace_iterator *iter, int flags, 1047 struct trace_event *event) 1048 { 1049 struct kretprobe_trace_entry_head *field; 1050 struct trace_seq *s = &iter->seq; 1051 struct trace_probe *tp; 1052 u8 *data; 1053 int i; 1054 1055 field = (struct kretprobe_trace_entry_head *)iter->ent; 1056 tp = container_of(event, struct trace_probe, call.event); 1057 1058 trace_seq_printf(s, "%s: (", trace_event_name(&tp->call)); 1059 1060 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) 1061 goto out; 1062 1063 trace_seq_puts(s, " <- "); 1064 1065 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) 1066 goto out; 1067 1068 trace_seq_putc(s, ')'); 1069 1070 data = (u8 *)&field[1]; 1071 for (i = 0; i < tp->nr_args; i++) 1072 if (!tp->args[i].type->print(s, tp->args[i].name, 1073 data + tp->args[i].offset, field)) 1074 goto out; 1075 1076 trace_seq_putc(s, '\n'); 1077 1078 out: 1079 return trace_handle_return(s); 1080 } 1081 1082 1083 static int kprobe_event_define_fields(struct trace_event_call *event_call) 1084 { 1085 int ret, i; 1086 struct kprobe_trace_entry_head field; 1087 struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data; 1088 1089 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); 1090 /* Set argument names as fields */ 1091 for (i = 0; i < tk->tp.nr_args; i++) { 1092 struct probe_arg *parg = &tk->tp.args[i]; 1093 1094 ret = trace_define_field(event_call, parg->type->fmttype, 1095 parg->name, 1096 sizeof(field) + parg->offset, 1097 parg->type->size, 1098 parg->type->is_signed, 1099 FILTER_OTHER); 1100 if (ret) 1101 return ret; 1102 } 1103 return 0; 1104 } 1105 1106 static int kretprobe_event_define_fields(struct trace_event_call *event_call) 1107 { 1108 int ret, i; 1109 struct kretprobe_trace_entry_head field; 1110 struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data; 1111 1112 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); 1113 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); 1114 /* Set argument names as fields */ 1115 for (i = 0; i < tk->tp.nr_args; i++) { 1116 struct probe_arg *parg = &tk->tp.args[i]; 1117 1118 ret = trace_define_field(event_call, parg->type->fmttype, 1119 parg->name, 1120 sizeof(field) + parg->offset, 1121 parg->type->size, 1122 parg->type->is_signed, 1123 FILTER_OTHER); 1124 if (ret) 1125 return ret; 1126 } 1127 return 0; 1128 } 1129 1130 #ifdef CONFIG_PERF_EVENTS 1131 1132 /* Kprobe profile handler */ 1133 static void 1134 kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) 1135 { 1136 struct trace_event_call *call = &tk->tp.call; 1137 struct bpf_prog *prog = call->prog; 1138 struct kprobe_trace_entry_head *entry; 1139 struct hlist_head *head; 1140 int size, __size, dsize; 1141 int rctx; 1142 1143 if (prog && !trace_call_bpf(prog, regs)) 1144 return; 1145 1146 head = this_cpu_ptr(call->perf_events); 1147 if (hlist_empty(head)) 1148 return; 1149 1150 dsize = __get_data_size(&tk->tp, regs); 1151 __size = sizeof(*entry) + tk->tp.size + dsize; 1152 size = ALIGN(__size + sizeof(u32), sizeof(u64)); 1153 size -= sizeof(u32); 1154 1155 entry = perf_trace_buf_prepare(size, call->event.type, NULL, &rctx); 1156 if (!entry) 1157 return; 1158 1159 entry->ip = (unsigned long)tk->rp.kp.addr; 1160 memset(&entry[1], 0, dsize); 1161 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); 1162 perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); 1163 } 1164 NOKPROBE_SYMBOL(kprobe_perf_func); 1165 1166 /* Kretprobe profile handler */ 1167 static void 1168 kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, 1169 struct pt_regs *regs) 1170 { 1171 struct trace_event_call *call = &tk->tp.call; 1172 struct bpf_prog *prog = call->prog; 1173 struct kretprobe_trace_entry_head *entry; 1174 struct hlist_head *head; 1175 int size, __size, dsize; 1176 int rctx; 1177 1178 if (prog && !trace_call_bpf(prog, regs)) 1179 return; 1180 1181 head = this_cpu_ptr(call->perf_events); 1182 if (hlist_empty(head)) 1183 return; 1184 1185 dsize = __get_data_size(&tk->tp, regs); 1186 __size = sizeof(*entry) + tk->tp.size + dsize; 1187 size = ALIGN(__size + sizeof(u32), sizeof(u64)); 1188 size -= sizeof(u32); 1189 1190 entry = perf_trace_buf_prepare(size, call->event.type, NULL, &rctx); 1191 if (!entry) 1192 return; 1193 1194 entry->func = (unsigned long)tk->rp.kp.addr; 1195 entry->ret_ip = (unsigned long)ri->ret_addr; 1196 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); 1197 perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); 1198 } 1199 NOKPROBE_SYMBOL(kretprobe_perf_func); 1200 #endif /* CONFIG_PERF_EVENTS */ 1201 1202 /* 1203 * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. 1204 * 1205 * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe 1206 * lockless, but we can't race with this __init function. 1207 */ 1208 static int kprobe_register(struct trace_event_call *event, 1209 enum trace_reg type, void *data) 1210 { 1211 struct trace_kprobe *tk = (struct trace_kprobe *)event->data; 1212 struct trace_event_file *file = data; 1213 1214 switch (type) { 1215 case TRACE_REG_REGISTER: 1216 return enable_trace_kprobe(tk, file); 1217 case TRACE_REG_UNREGISTER: 1218 return disable_trace_kprobe(tk, file); 1219 1220 #ifdef CONFIG_PERF_EVENTS 1221 case TRACE_REG_PERF_REGISTER: 1222 return enable_trace_kprobe(tk, NULL); 1223 case TRACE_REG_PERF_UNREGISTER: 1224 return disable_trace_kprobe(tk, NULL); 1225 case TRACE_REG_PERF_OPEN: 1226 case TRACE_REG_PERF_CLOSE: 1227 case TRACE_REG_PERF_ADD: 1228 case TRACE_REG_PERF_DEL: 1229 return 0; 1230 #endif 1231 } 1232 return 0; 1233 } 1234 1235 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) 1236 { 1237 struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); 1238 1239 raw_cpu_inc(*tk->nhit); 1240 1241 if (tk->tp.flags & TP_FLAG_TRACE) 1242 kprobe_trace_func(tk, regs); 1243 #ifdef CONFIG_PERF_EVENTS 1244 if (tk->tp.flags & TP_FLAG_PROFILE) 1245 kprobe_perf_func(tk, regs); 1246 #endif 1247 return 0; /* We don't tweek kernel, so just return 0 */ 1248 } 1249 NOKPROBE_SYMBOL(kprobe_dispatcher); 1250 1251 static int 1252 kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) 1253 { 1254 struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp); 1255 1256 raw_cpu_inc(*tk->nhit); 1257 1258 if (tk->tp.flags & TP_FLAG_TRACE) 1259 kretprobe_trace_func(tk, ri, regs); 1260 #ifdef CONFIG_PERF_EVENTS 1261 if (tk->tp.flags & TP_FLAG_PROFILE) 1262 kretprobe_perf_func(tk, ri, regs); 1263 #endif 1264 return 0; /* We don't tweek kernel, so just return 0 */ 1265 } 1266 NOKPROBE_SYMBOL(kretprobe_dispatcher); 1267 1268 static struct trace_event_functions kretprobe_funcs = { 1269 .trace = print_kretprobe_event 1270 }; 1271 1272 static struct trace_event_functions kprobe_funcs = { 1273 .trace = print_kprobe_event 1274 }; 1275 1276 static int register_kprobe_event(struct trace_kprobe *tk) 1277 { 1278 struct trace_event_call *call = &tk->tp.call; 1279 int ret; 1280 1281 /* Initialize trace_event_call */ 1282 INIT_LIST_HEAD(&call->class->fields); 1283 if (trace_kprobe_is_return(tk)) { 1284 call->event.funcs = &kretprobe_funcs; 1285 call->class->define_fields = kretprobe_event_define_fields; 1286 } else { 1287 call->event.funcs = &kprobe_funcs; 1288 call->class->define_fields = kprobe_event_define_fields; 1289 } 1290 if (set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) 1291 return -ENOMEM; 1292 ret = register_trace_event(&call->event); 1293 if (!ret) { 1294 kfree(call->print_fmt); 1295 return -ENODEV; 1296 } 1297 call->flags = TRACE_EVENT_FL_KPROBE; 1298 call->class->reg = kprobe_register; 1299 call->data = tk; 1300 ret = trace_add_event_call(call); 1301 if (ret) { 1302 pr_info("Failed to register kprobe event: %s\n", 1303 trace_event_name(call)); 1304 kfree(call->print_fmt); 1305 unregister_trace_event(&call->event); 1306 } 1307 return ret; 1308 } 1309 1310 static int unregister_kprobe_event(struct trace_kprobe *tk) 1311 { 1312 int ret; 1313 1314 /* tp->event is unregistered in trace_remove_event_call() */ 1315 ret = trace_remove_event_call(&tk->tp.call); 1316 if (!ret) 1317 kfree(tk->tp.call.print_fmt); 1318 return ret; 1319 } 1320 1321 /* Make a tracefs interface for controlling probe points */ 1322 static __init int init_kprobe_trace(void) 1323 { 1324 struct dentry *d_tracer; 1325 struct dentry *entry; 1326 1327 if (register_module_notifier(&trace_kprobe_module_nb)) 1328 return -EINVAL; 1329 1330 d_tracer = tracing_init_dentry(); 1331 if (IS_ERR(d_tracer)) 1332 return 0; 1333 1334 entry = tracefs_create_file("kprobe_events", 0644, d_tracer, 1335 NULL, &kprobe_events_ops); 1336 1337 /* Event list interface */ 1338 if (!entry) 1339 pr_warning("Could not create tracefs " 1340 "'kprobe_events' entry\n"); 1341 1342 /* Profile interface */ 1343 entry = tracefs_create_file("kprobe_profile", 0444, d_tracer, 1344 NULL, &kprobe_profile_ops); 1345 1346 if (!entry) 1347 pr_warning("Could not create tracefs " 1348 "'kprobe_profile' entry\n"); 1349 return 0; 1350 } 1351 fs_initcall(init_kprobe_trace); 1352 1353 1354 #ifdef CONFIG_FTRACE_STARTUP_TEST 1355 1356 /* 1357 * The "__used" keeps gcc from removing the function symbol 1358 * from the kallsyms table. 1359 */ 1360 static __used int kprobe_trace_selftest_target(int a1, int a2, int a3, 1361 int a4, int a5, int a6) 1362 { 1363 return a1 + a2 + a3 + a4 + a5 + a6; 1364 } 1365 1366 static struct trace_event_file * 1367 find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) 1368 { 1369 struct trace_event_file *file; 1370 1371 list_for_each_entry(file, &tr->events, list) 1372 if (file->event_call == &tk->tp.call) 1373 return file; 1374 1375 return NULL; 1376 } 1377 1378 /* 1379 * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this 1380 * stage, we can do this lockless. 1381 */ 1382 static __init int kprobe_trace_self_tests_init(void) 1383 { 1384 int ret, warn = 0; 1385 int (*target)(int, int, int, int, int, int); 1386 struct trace_kprobe *tk; 1387 struct trace_event_file *file; 1388 1389 if (tracing_is_disabled()) 1390 return -ENODEV; 1391 1392 target = kprobe_trace_selftest_target; 1393 1394 pr_info("Testing kprobe tracing: "); 1395 1396 ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target " 1397 "$stack $stack0 +0($stack)", 1398 create_trace_kprobe); 1399 if (WARN_ON_ONCE(ret)) { 1400 pr_warn("error on probing function entry.\n"); 1401 warn++; 1402 } else { 1403 /* Enable trace point */ 1404 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); 1405 if (WARN_ON_ONCE(tk == NULL)) { 1406 pr_warn("error on getting new probe.\n"); 1407 warn++; 1408 } else { 1409 file = find_trace_probe_file(tk, top_trace_array()); 1410 if (WARN_ON_ONCE(file == NULL)) { 1411 pr_warn("error on getting probe file.\n"); 1412 warn++; 1413 } else 1414 enable_trace_kprobe(tk, file); 1415 } 1416 } 1417 1418 ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target " 1419 "$retval", create_trace_kprobe); 1420 if (WARN_ON_ONCE(ret)) { 1421 pr_warn("error on probing function return.\n"); 1422 warn++; 1423 } else { 1424 /* Enable trace point */ 1425 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); 1426 if (WARN_ON_ONCE(tk == NULL)) { 1427 pr_warn("error on getting 2nd new probe.\n"); 1428 warn++; 1429 } else { 1430 file = find_trace_probe_file(tk, top_trace_array()); 1431 if (WARN_ON_ONCE(file == NULL)) { 1432 pr_warn("error on getting probe file.\n"); 1433 warn++; 1434 } else 1435 enable_trace_kprobe(tk, file); 1436 } 1437 } 1438 1439 if (warn) 1440 goto end; 1441 1442 ret = target(1, 2, 3, 4, 5, 6); 1443 1444 /* Disable trace points before removing it */ 1445 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); 1446 if (WARN_ON_ONCE(tk == NULL)) { 1447 pr_warn("error on getting test probe.\n"); 1448 warn++; 1449 } else { 1450 file = find_trace_probe_file(tk, top_trace_array()); 1451 if (WARN_ON_ONCE(file == NULL)) { 1452 pr_warn("error on getting probe file.\n"); 1453 warn++; 1454 } else 1455 disable_trace_kprobe(tk, file); 1456 } 1457 1458 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); 1459 if (WARN_ON_ONCE(tk == NULL)) { 1460 pr_warn("error on getting 2nd test probe.\n"); 1461 warn++; 1462 } else { 1463 file = find_trace_probe_file(tk, top_trace_array()); 1464 if (WARN_ON_ONCE(file == NULL)) { 1465 pr_warn("error on getting probe file.\n"); 1466 warn++; 1467 } else 1468 disable_trace_kprobe(tk, file); 1469 } 1470 1471 ret = traceprobe_command("-:testprobe", create_trace_kprobe); 1472 if (WARN_ON_ONCE(ret)) { 1473 pr_warn("error on deleting a probe.\n"); 1474 warn++; 1475 } 1476 1477 ret = traceprobe_command("-:testprobe2", create_trace_kprobe); 1478 if (WARN_ON_ONCE(ret)) { 1479 pr_warn("error on deleting a probe.\n"); 1480 warn++; 1481 } 1482 1483 end: 1484 release_all_trace_kprobes(); 1485 if (warn) 1486 pr_cont("NG: Some tests are failed. Please check them.\n"); 1487 else 1488 pr_cont("OK\n"); 1489 return 0; 1490 } 1491 1492 late_initcall(kprobe_trace_self_tests_init); 1493 1494 #endif 1495