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 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 long ret; 169 int maxlen = get_rloc_len(*(u32 *)dest); 170 u8 *dst = get_rloc_data(dest); 171 u8 *src = addr; 172 mm_segment_t old_fs = get_fs(); 173 174 if (!maxlen) 175 return; 176 177 /* 178 * Try to get string again, since the string can be changed while 179 * probing. 180 */ 181 set_fs(KERNEL_DS); 182 pagefault_disable(); 183 184 do 185 ret = __copy_from_user_inatomic(dst++, src++, 1); 186 while (dst[-1] && ret == 0 && src - (u8 *)addr < maxlen); 187 188 dst[-1] = '\0'; 189 pagefault_enable(); 190 set_fs(old_fs); 191 192 if (ret < 0) { /* Failed to fetch string */ 193 ((u8 *)get_rloc_data(dest))[0] = '\0'; 194 *(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest)); 195 } else { 196 *(u32 *)dest = make_data_rloc(src - (u8 *)addr, 197 get_rloc_offs(*(u32 *)dest)); 198 } 199 } 200 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string)); 201 202 /* Return the length of string -- including null terminal byte */ 203 static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, 204 void *addr, void *dest) 205 { 206 mm_segment_t old_fs; 207 int ret, len = 0; 208 u8 c; 209 210 old_fs = get_fs(); 211 set_fs(KERNEL_DS); 212 pagefault_disable(); 213 214 do { 215 ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1); 216 len++; 217 } while (c && ret == 0 && len < MAX_STRING_SIZE); 218 219 pagefault_enable(); 220 set_fs(old_fs); 221 222 if (ret < 0) /* Failed to check the length */ 223 *(u32 *)dest = 0; 224 else 225 *(u32 *)dest = len; 226 } 227 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string_size)); 228 229 #define DEFINE_FETCH_symbol(type) \ 230 void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, void *data, void *dest)\ 231 { \ 232 struct symbol_cache *sc = data; \ 233 if (sc->addr) \ 234 fetch_memory_##type(regs, (void *)sc->addr, dest); \ 235 else \ 236 *(type *)dest = 0; \ 237 } \ 238 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(symbol, type)); 239 240 DEFINE_BASIC_FETCH_FUNCS(symbol) 241 DEFINE_FETCH_symbol(string) 242 DEFINE_FETCH_symbol(string_size) 243 244 /* kprobes don't support file_offset fetch methods */ 245 #define fetch_file_offset_u8 NULL 246 #define fetch_file_offset_u16 NULL 247 #define fetch_file_offset_u32 NULL 248 #define fetch_file_offset_u64 NULL 249 #define fetch_file_offset_string NULL 250 #define fetch_file_offset_string_size NULL 251 252 /* Fetch type information table */ 253 const struct fetch_type kprobes_fetch_type_table[] = { 254 /* Special types */ 255 [FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string, 256 sizeof(u32), 1, "__data_loc char[]"), 257 [FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32, 258 string_size, sizeof(u32), 0, "u32"), 259 /* Basic types */ 260 ASSIGN_FETCH_TYPE(u8, u8, 0), 261 ASSIGN_FETCH_TYPE(u16, u16, 0), 262 ASSIGN_FETCH_TYPE(u32, u32, 0), 263 ASSIGN_FETCH_TYPE(u64, u64, 0), 264 ASSIGN_FETCH_TYPE(s8, u8, 1), 265 ASSIGN_FETCH_TYPE(s16, u16, 1), 266 ASSIGN_FETCH_TYPE(s32, u32, 1), 267 ASSIGN_FETCH_TYPE(s64, u64, 1), 268 269 ASSIGN_FETCH_TYPE_END 270 }; 271 272 /* 273 * Allocate new trace_probe and initialize it (including kprobes). 274 */ 275 static struct trace_kprobe *alloc_trace_kprobe(const char *group, 276 const char *event, 277 void *addr, 278 const char *symbol, 279 unsigned long offs, 280 int nargs, bool is_return) 281 { 282 struct trace_kprobe *tk; 283 int ret = -ENOMEM; 284 285 tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL); 286 if (!tk) 287 return ERR_PTR(ret); 288 289 if (symbol) { 290 tk->symbol = kstrdup(symbol, GFP_KERNEL); 291 if (!tk->symbol) 292 goto error; 293 tk->rp.kp.symbol_name = tk->symbol; 294 tk->rp.kp.offset = offs; 295 } else 296 tk->rp.kp.addr = addr; 297 298 if (is_return) 299 tk->rp.handler = kretprobe_dispatcher; 300 else 301 tk->rp.kp.pre_handler = kprobe_dispatcher; 302 303 if (!event || !is_good_name(event)) { 304 ret = -EINVAL; 305 goto error; 306 } 307 308 tk->tp.call.class = &tk->tp.class; 309 tk->tp.call.name = kstrdup(event, GFP_KERNEL); 310 if (!tk->tp.call.name) 311 goto error; 312 313 if (!group || !is_good_name(group)) { 314 ret = -EINVAL; 315 goto error; 316 } 317 318 tk->tp.class.system = kstrdup(group, GFP_KERNEL); 319 if (!tk->tp.class.system) 320 goto error; 321 322 INIT_LIST_HEAD(&tk->list); 323 INIT_LIST_HEAD(&tk->tp.files); 324 return tk; 325 error: 326 kfree(tk->tp.call.name); 327 kfree(tk->symbol); 328 kfree(tk); 329 return ERR_PTR(ret); 330 } 331 332 static void free_trace_kprobe(struct trace_kprobe *tk) 333 { 334 int i; 335 336 for (i = 0; i < tk->tp.nr_args; i++) 337 traceprobe_free_probe_arg(&tk->tp.args[i]); 338 339 kfree(tk->tp.call.class->system); 340 kfree(tk->tp.call.name); 341 kfree(tk->symbol); 342 kfree(tk); 343 } 344 345 static struct trace_kprobe *find_trace_kprobe(const char *event, 346 const char *group) 347 { 348 struct trace_kprobe *tk; 349 350 list_for_each_entry(tk, &probe_list, list) 351 if (strcmp(ftrace_event_name(&tk->tp.call), event) == 0 && 352 strcmp(tk->tp.call.class->system, group) == 0) 353 return tk; 354 return NULL; 355 } 356 357 /* 358 * Enable trace_probe 359 * if the file is NULL, enable "perf" handler, or enable "trace" handler. 360 */ 361 static int 362 enable_trace_kprobe(struct trace_kprobe *tk, struct ftrace_event_file *file) 363 { 364 int ret = 0; 365 366 if (file) { 367 struct event_file_link *link; 368 369 link = kmalloc(sizeof(*link), GFP_KERNEL); 370 if (!link) { 371 ret = -ENOMEM; 372 goto out; 373 } 374 375 link->file = file; 376 list_add_tail_rcu(&link->list, &tk->tp.files); 377 378 tk->tp.flags |= TP_FLAG_TRACE; 379 } else 380 tk->tp.flags |= TP_FLAG_PROFILE; 381 382 if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) { 383 if (trace_kprobe_is_return(tk)) 384 ret = enable_kretprobe(&tk->rp); 385 else 386 ret = enable_kprobe(&tk->rp.kp); 387 } 388 out: 389 return ret; 390 } 391 392 /* 393 * Disable trace_probe 394 * if the file is NULL, disable "perf" handler, or disable "trace" handler. 395 */ 396 static int 397 disable_trace_kprobe(struct trace_kprobe *tk, struct ftrace_event_file *file) 398 { 399 struct event_file_link *link = NULL; 400 int wait = 0; 401 int ret = 0; 402 403 if (file) { 404 link = find_event_file_link(&tk->tp, file); 405 if (!link) { 406 ret = -EINVAL; 407 goto out; 408 } 409 410 list_del_rcu(&link->list); 411 wait = 1; 412 if (!list_empty(&tk->tp.files)) 413 goto out; 414 415 tk->tp.flags &= ~TP_FLAG_TRACE; 416 } else 417 tk->tp.flags &= ~TP_FLAG_PROFILE; 418 419 if (!trace_probe_is_enabled(&tk->tp) && trace_probe_is_registered(&tk->tp)) { 420 if (trace_kprobe_is_return(tk)) 421 disable_kretprobe(&tk->rp); 422 else 423 disable_kprobe(&tk->rp.kp); 424 wait = 1; 425 } 426 out: 427 if (wait) { 428 /* 429 * Synchronize with kprobe_trace_func/kretprobe_trace_func 430 * to ensure disabled (all running handlers are finished). 431 * This is not only for kfree(), but also the caller, 432 * trace_remove_event_call() supposes it for releasing 433 * event_call related objects, which will be accessed in 434 * the kprobe_trace_func/kretprobe_trace_func. 435 */ 436 synchronize_sched(); 437 kfree(link); /* Ignored if link == NULL */ 438 } 439 440 return ret; 441 } 442 443 /* Internal register function - just handle k*probes and flags */ 444 static int __register_trace_kprobe(struct trace_kprobe *tk) 445 { 446 int i, ret; 447 448 if (trace_probe_is_registered(&tk->tp)) 449 return -EINVAL; 450 451 for (i = 0; i < tk->tp.nr_args; i++) 452 traceprobe_update_arg(&tk->tp.args[i]); 453 454 /* Set/clear disabled flag according to tp->flag */ 455 if (trace_probe_is_enabled(&tk->tp)) 456 tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; 457 else 458 tk->rp.kp.flags |= KPROBE_FLAG_DISABLED; 459 460 if (trace_kprobe_is_return(tk)) 461 ret = register_kretprobe(&tk->rp); 462 else 463 ret = register_kprobe(&tk->rp.kp); 464 465 if (ret == 0) 466 tk->tp.flags |= TP_FLAG_REGISTERED; 467 else { 468 pr_warning("Could not insert probe at %s+%lu: %d\n", 469 trace_kprobe_symbol(tk), trace_kprobe_offset(tk), ret); 470 if (ret == -ENOENT && trace_kprobe_is_on_module(tk)) { 471 pr_warning("This probe might be able to register after" 472 "target module is loaded. Continue.\n"); 473 ret = 0; 474 } else if (ret == -EILSEQ) { 475 pr_warning("Probing address(0x%p) is not an " 476 "instruction boundary.\n", 477 tk->rp.kp.addr); 478 ret = -EINVAL; 479 } 480 } 481 482 return ret; 483 } 484 485 /* Internal unregister function - just handle k*probes and flags */ 486 static void __unregister_trace_kprobe(struct trace_kprobe *tk) 487 { 488 if (trace_probe_is_registered(&tk->tp)) { 489 if (trace_kprobe_is_return(tk)) 490 unregister_kretprobe(&tk->rp); 491 else 492 unregister_kprobe(&tk->rp.kp); 493 tk->tp.flags &= ~TP_FLAG_REGISTERED; 494 /* Cleanup kprobe for reuse */ 495 if (tk->rp.kp.symbol_name) 496 tk->rp.kp.addr = NULL; 497 } 498 } 499 500 /* Unregister a trace_probe and probe_event: call with locking probe_lock */ 501 static int unregister_trace_kprobe(struct trace_kprobe *tk) 502 { 503 /* Enabled event can not be unregistered */ 504 if (trace_probe_is_enabled(&tk->tp)) 505 return -EBUSY; 506 507 /* Will fail if probe is being used by ftrace or perf */ 508 if (unregister_kprobe_event(tk)) 509 return -EBUSY; 510 511 __unregister_trace_kprobe(tk); 512 list_del(&tk->list); 513 514 return 0; 515 } 516 517 /* Register a trace_probe and probe_event */ 518 static int register_trace_kprobe(struct trace_kprobe *tk) 519 { 520 struct trace_kprobe *old_tk; 521 int ret; 522 523 mutex_lock(&probe_lock); 524 525 /* Delete old (same name) event if exist */ 526 old_tk = find_trace_kprobe(ftrace_event_name(&tk->tp.call), 527 tk->tp.call.class->system); 528 if (old_tk) { 529 ret = unregister_trace_kprobe(old_tk); 530 if (ret < 0) 531 goto end; 532 free_trace_kprobe(old_tk); 533 } 534 535 /* Register new event */ 536 ret = register_kprobe_event(tk); 537 if (ret) { 538 pr_warning("Failed to register probe event(%d)\n", ret); 539 goto end; 540 } 541 542 /* Register k*probe */ 543 ret = __register_trace_kprobe(tk); 544 if (ret < 0) 545 unregister_kprobe_event(tk); 546 else 547 list_add_tail(&tk->list, &probe_list); 548 549 end: 550 mutex_unlock(&probe_lock); 551 return ret; 552 } 553 554 /* Module notifier call back, checking event on the module */ 555 static int trace_kprobe_module_callback(struct notifier_block *nb, 556 unsigned long val, void *data) 557 { 558 struct module *mod = data; 559 struct trace_kprobe *tk; 560 int ret; 561 562 if (val != MODULE_STATE_COMING) 563 return NOTIFY_DONE; 564 565 /* Update probes on coming module */ 566 mutex_lock(&probe_lock); 567 list_for_each_entry(tk, &probe_list, list) { 568 if (trace_kprobe_within_module(tk, mod)) { 569 /* Don't need to check busy - this should have gone. */ 570 __unregister_trace_kprobe(tk); 571 ret = __register_trace_kprobe(tk); 572 if (ret) 573 pr_warning("Failed to re-register probe %s on" 574 "%s: %d\n", 575 ftrace_event_name(&tk->tp.call), 576 mod->name, ret); 577 } 578 } 579 mutex_unlock(&probe_lock); 580 581 return NOTIFY_DONE; 582 } 583 584 static struct notifier_block trace_kprobe_module_nb = { 585 .notifier_call = trace_kprobe_module_callback, 586 .priority = 1 /* Invoked after kprobe module callback */ 587 }; 588 589 static int create_trace_kprobe(int argc, char **argv) 590 { 591 /* 592 * Argument syntax: 593 * - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] 594 * - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS] 595 * Fetch args: 596 * $retval : fetch return value 597 * $stack : fetch stack address 598 * $stackN : fetch Nth of stack (N:0-) 599 * @ADDR : fetch memory at ADDR (ADDR should be in kernel) 600 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) 601 * %REG : fetch register REG 602 * Dereferencing memory fetch: 603 * +|-offs(ARG) : fetch memory at ARG +|- offs address. 604 * Alias name of args: 605 * NAME=FETCHARG : set NAME as alias of FETCHARG. 606 * Type of args: 607 * FETCHARG:TYPE : use TYPE instead of unsigned long. 608 */ 609 struct trace_kprobe *tk; 610 int i, ret = 0; 611 bool is_return = false, is_delete = false; 612 char *symbol = NULL, *event = NULL, *group = NULL; 613 char *arg; 614 unsigned long offset = 0; 615 void *addr = NULL; 616 char buf[MAX_EVENT_NAME_LEN]; 617 618 /* argc must be >= 1 */ 619 if (argv[0][0] == 'p') 620 is_return = false; 621 else if (argv[0][0] == 'r') 622 is_return = true; 623 else if (argv[0][0] == '-') 624 is_delete = true; 625 else { 626 pr_info("Probe definition must be started with 'p', 'r' or" 627 " '-'.\n"); 628 return -EINVAL; 629 } 630 631 if (argv[0][1] == ':') { 632 event = &argv[0][2]; 633 if (strchr(event, '/')) { 634 group = event; 635 event = strchr(group, '/') + 1; 636 event[-1] = '\0'; 637 if (strlen(group) == 0) { 638 pr_info("Group name is not specified\n"); 639 return -EINVAL; 640 } 641 } 642 if (strlen(event) == 0) { 643 pr_info("Event name is not specified\n"); 644 return -EINVAL; 645 } 646 } 647 if (!group) 648 group = KPROBE_EVENT_SYSTEM; 649 650 if (is_delete) { 651 if (!event) { 652 pr_info("Delete command needs an event name.\n"); 653 return -EINVAL; 654 } 655 mutex_lock(&probe_lock); 656 tk = find_trace_kprobe(event, group); 657 if (!tk) { 658 mutex_unlock(&probe_lock); 659 pr_info("Event %s/%s doesn't exist.\n", group, event); 660 return -ENOENT; 661 } 662 /* delete an event */ 663 ret = unregister_trace_kprobe(tk); 664 if (ret == 0) 665 free_trace_kprobe(tk); 666 mutex_unlock(&probe_lock); 667 return ret; 668 } 669 670 if (argc < 2) { 671 pr_info("Probe point is not specified.\n"); 672 return -EINVAL; 673 } 674 if (isdigit(argv[1][0])) { 675 if (is_return) { 676 pr_info("Return probe point must be a symbol.\n"); 677 return -EINVAL; 678 } 679 /* an address specified */ 680 ret = kstrtoul(&argv[1][0], 0, (unsigned long *)&addr); 681 if (ret) { 682 pr_info("Failed to parse address.\n"); 683 return ret; 684 } 685 } else { 686 /* a symbol specified */ 687 symbol = argv[1]; 688 /* TODO: support .init module functions */ 689 ret = traceprobe_split_symbol_offset(symbol, &offset); 690 if (ret) { 691 pr_info("Failed to parse symbol.\n"); 692 return ret; 693 } 694 if (offset && is_return) { 695 pr_info("Return probe must be used without offset.\n"); 696 return -EINVAL; 697 } 698 } 699 argc -= 2; argv += 2; 700 701 /* setup a probe */ 702 if (!event) { 703 /* Make a new event name */ 704 if (symbol) 705 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", 706 is_return ? 'r' : 'p', symbol, offset); 707 else 708 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", 709 is_return ? 'r' : 'p', addr); 710 event = buf; 711 } 712 tk = alloc_trace_kprobe(group, event, addr, symbol, offset, argc, 713 is_return); 714 if (IS_ERR(tk)) { 715 pr_info("Failed to allocate trace_probe.(%d)\n", 716 (int)PTR_ERR(tk)); 717 return PTR_ERR(tk); 718 } 719 720 /* parse arguments */ 721 ret = 0; 722 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { 723 struct probe_arg *parg = &tk->tp.args[i]; 724 725 /* Increment count for freeing args in error case */ 726 tk->tp.nr_args++; 727 728 /* Parse argument name */ 729 arg = strchr(argv[i], '='); 730 if (arg) { 731 *arg++ = '\0'; 732 parg->name = kstrdup(argv[i], GFP_KERNEL); 733 } else { 734 arg = argv[i]; 735 /* If argument name is omitted, set "argN" */ 736 snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); 737 parg->name = kstrdup(buf, GFP_KERNEL); 738 } 739 740 if (!parg->name) { 741 pr_info("Failed to allocate argument[%d] name.\n", i); 742 ret = -ENOMEM; 743 goto error; 744 } 745 746 if (!is_good_name(parg->name)) { 747 pr_info("Invalid argument[%d] name: %s\n", 748 i, parg->name); 749 ret = -EINVAL; 750 goto error; 751 } 752 753 if (traceprobe_conflict_field_name(parg->name, 754 tk->tp.args, i)) { 755 pr_info("Argument[%d] name '%s' conflicts with " 756 "another field.\n", i, argv[i]); 757 ret = -EINVAL; 758 goto error; 759 } 760 761 /* Parse fetch argument */ 762 ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg, 763 is_return, true); 764 if (ret) { 765 pr_info("Parse error at argument[%d]. (%d)\n", i, ret); 766 goto error; 767 } 768 } 769 770 ret = register_trace_kprobe(tk); 771 if (ret) 772 goto error; 773 return 0; 774 775 error: 776 free_trace_kprobe(tk); 777 return ret; 778 } 779 780 static int release_all_trace_kprobes(void) 781 { 782 struct trace_kprobe *tk; 783 int ret = 0; 784 785 mutex_lock(&probe_lock); 786 /* Ensure no probe is in use. */ 787 list_for_each_entry(tk, &probe_list, list) 788 if (trace_probe_is_enabled(&tk->tp)) { 789 ret = -EBUSY; 790 goto end; 791 } 792 /* TODO: Use batch unregistration */ 793 while (!list_empty(&probe_list)) { 794 tk = list_entry(probe_list.next, struct trace_kprobe, list); 795 ret = unregister_trace_kprobe(tk); 796 if (ret) 797 goto end; 798 free_trace_kprobe(tk); 799 } 800 801 end: 802 mutex_unlock(&probe_lock); 803 804 return ret; 805 } 806 807 /* Probes listing interfaces */ 808 static void *probes_seq_start(struct seq_file *m, loff_t *pos) 809 { 810 mutex_lock(&probe_lock); 811 return seq_list_start(&probe_list, *pos); 812 } 813 814 static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) 815 { 816 return seq_list_next(v, &probe_list, pos); 817 } 818 819 static void probes_seq_stop(struct seq_file *m, void *v) 820 { 821 mutex_unlock(&probe_lock); 822 } 823 824 static int probes_seq_show(struct seq_file *m, void *v) 825 { 826 struct trace_kprobe *tk = v; 827 int i; 828 829 seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p'); 830 seq_printf(m, ":%s/%s", tk->tp.call.class->system, 831 ftrace_event_name(&tk->tp.call)); 832 833 if (!tk->symbol) 834 seq_printf(m, " 0x%p", tk->rp.kp.addr); 835 else if (tk->rp.kp.offset) 836 seq_printf(m, " %s+%u", trace_kprobe_symbol(tk), 837 tk->rp.kp.offset); 838 else 839 seq_printf(m, " %s", trace_kprobe_symbol(tk)); 840 841 for (i = 0; i < tk->tp.nr_args; i++) 842 seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm); 843 seq_putc(m, '\n'); 844 845 return 0; 846 } 847 848 static const struct seq_operations probes_seq_op = { 849 .start = probes_seq_start, 850 .next = probes_seq_next, 851 .stop = probes_seq_stop, 852 .show = probes_seq_show 853 }; 854 855 static int probes_open(struct inode *inode, struct file *file) 856 { 857 int ret; 858 859 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { 860 ret = release_all_trace_kprobes(); 861 if (ret < 0) 862 return ret; 863 } 864 865 return seq_open(file, &probes_seq_op); 866 } 867 868 static ssize_t probes_write(struct file *file, const char __user *buffer, 869 size_t count, loff_t *ppos) 870 { 871 return traceprobe_probes_write(file, buffer, count, ppos, 872 create_trace_kprobe); 873 } 874 875 static const struct file_operations kprobe_events_ops = { 876 .owner = THIS_MODULE, 877 .open = probes_open, 878 .read = seq_read, 879 .llseek = seq_lseek, 880 .release = seq_release, 881 .write = probes_write, 882 }; 883 884 /* Probes profiling interfaces */ 885 static int probes_profile_seq_show(struct seq_file *m, void *v) 886 { 887 struct trace_kprobe *tk = v; 888 889 seq_printf(m, " %-44s %15lu %15lu\n", 890 ftrace_event_name(&tk->tp.call), tk->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 ftrace_event_file *ftrace_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 ftrace_event_call *call = &tk->tp.call; 927 928 WARN_ON(call != ftrace_file->event_call); 929 930 if (ftrace_trigger_soft_disabled(ftrace_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, ftrace_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(ftrace_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 ftrace_event_file *ftrace_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 ftrace_event_call *call = &tk->tp.call; 975 976 WARN_ON(call != ftrace_file->event_call); 977 978 if (ftrace_trigger_soft_disabled(ftrace_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, ftrace_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(ftrace_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: (", ftrace_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: (", ftrace_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 ftrace_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 ftrace_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 ftrace_event_call *call = &tk->tp.call; 1137 struct kprobe_trace_entry_head *entry; 1138 struct hlist_head *head; 1139 int size, __size, dsize; 1140 int rctx; 1141 1142 head = this_cpu_ptr(call->perf_events); 1143 if (hlist_empty(head)) 1144 return; 1145 1146 dsize = __get_data_size(&tk->tp, regs); 1147 __size = sizeof(*entry) + tk->tp.size + dsize; 1148 size = ALIGN(__size + sizeof(u32), sizeof(u64)); 1149 size -= sizeof(u32); 1150 1151 entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); 1152 if (!entry) 1153 return; 1154 1155 entry->ip = (unsigned long)tk->rp.kp.addr; 1156 memset(&entry[1], 0, dsize); 1157 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); 1158 perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); 1159 } 1160 NOKPROBE_SYMBOL(kprobe_perf_func); 1161 1162 /* Kretprobe profile handler */ 1163 static void 1164 kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, 1165 struct pt_regs *regs) 1166 { 1167 struct ftrace_event_call *call = &tk->tp.call; 1168 struct kretprobe_trace_entry_head *entry; 1169 struct hlist_head *head; 1170 int size, __size, dsize; 1171 int rctx; 1172 1173 head = this_cpu_ptr(call->perf_events); 1174 if (hlist_empty(head)) 1175 return; 1176 1177 dsize = __get_data_size(&tk->tp, regs); 1178 __size = sizeof(*entry) + tk->tp.size + dsize; 1179 size = ALIGN(__size + sizeof(u32), sizeof(u64)); 1180 size -= sizeof(u32); 1181 1182 entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx); 1183 if (!entry) 1184 return; 1185 1186 entry->func = (unsigned long)tk->rp.kp.addr; 1187 entry->ret_ip = (unsigned long)ri->ret_addr; 1188 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); 1189 perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); 1190 } 1191 NOKPROBE_SYMBOL(kretprobe_perf_func); 1192 #endif /* CONFIG_PERF_EVENTS */ 1193 1194 /* 1195 * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. 1196 * 1197 * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe 1198 * lockless, but we can't race with this __init function. 1199 */ 1200 static int kprobe_register(struct ftrace_event_call *event, 1201 enum trace_reg type, void *data) 1202 { 1203 struct trace_kprobe *tk = (struct trace_kprobe *)event->data; 1204 struct ftrace_event_file *file = data; 1205 1206 switch (type) { 1207 case TRACE_REG_REGISTER: 1208 return enable_trace_kprobe(tk, file); 1209 case TRACE_REG_UNREGISTER: 1210 return disable_trace_kprobe(tk, file); 1211 1212 #ifdef CONFIG_PERF_EVENTS 1213 case TRACE_REG_PERF_REGISTER: 1214 return enable_trace_kprobe(tk, NULL); 1215 case TRACE_REG_PERF_UNREGISTER: 1216 return disable_trace_kprobe(tk, NULL); 1217 case TRACE_REG_PERF_OPEN: 1218 case TRACE_REG_PERF_CLOSE: 1219 case TRACE_REG_PERF_ADD: 1220 case TRACE_REG_PERF_DEL: 1221 return 0; 1222 #endif 1223 } 1224 return 0; 1225 } 1226 1227 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) 1228 { 1229 struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); 1230 1231 tk->nhit++; 1232 1233 if (tk->tp.flags & TP_FLAG_TRACE) 1234 kprobe_trace_func(tk, regs); 1235 #ifdef CONFIG_PERF_EVENTS 1236 if (tk->tp.flags & TP_FLAG_PROFILE) 1237 kprobe_perf_func(tk, regs); 1238 #endif 1239 return 0; /* We don't tweek kernel, so just return 0 */ 1240 } 1241 NOKPROBE_SYMBOL(kprobe_dispatcher); 1242 1243 static int 1244 kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) 1245 { 1246 struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp); 1247 1248 tk->nhit++; 1249 1250 if (tk->tp.flags & TP_FLAG_TRACE) 1251 kretprobe_trace_func(tk, ri, regs); 1252 #ifdef CONFIG_PERF_EVENTS 1253 if (tk->tp.flags & TP_FLAG_PROFILE) 1254 kretprobe_perf_func(tk, ri, regs); 1255 #endif 1256 return 0; /* We don't tweek kernel, so just return 0 */ 1257 } 1258 NOKPROBE_SYMBOL(kretprobe_dispatcher); 1259 1260 static struct trace_event_functions kretprobe_funcs = { 1261 .trace = print_kretprobe_event 1262 }; 1263 1264 static struct trace_event_functions kprobe_funcs = { 1265 .trace = print_kprobe_event 1266 }; 1267 1268 static int register_kprobe_event(struct trace_kprobe *tk) 1269 { 1270 struct ftrace_event_call *call = &tk->tp.call; 1271 int ret; 1272 1273 /* Initialize ftrace_event_call */ 1274 INIT_LIST_HEAD(&call->class->fields); 1275 if (trace_kprobe_is_return(tk)) { 1276 call->event.funcs = &kretprobe_funcs; 1277 call->class->define_fields = kretprobe_event_define_fields; 1278 } else { 1279 call->event.funcs = &kprobe_funcs; 1280 call->class->define_fields = kprobe_event_define_fields; 1281 } 1282 if (set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) 1283 return -ENOMEM; 1284 ret = register_ftrace_event(&call->event); 1285 if (!ret) { 1286 kfree(call->print_fmt); 1287 return -ENODEV; 1288 } 1289 call->flags = 0; 1290 call->class->reg = kprobe_register; 1291 call->data = tk; 1292 ret = trace_add_event_call(call); 1293 if (ret) { 1294 pr_info("Failed to register kprobe event: %s\n", 1295 ftrace_event_name(call)); 1296 kfree(call->print_fmt); 1297 unregister_ftrace_event(&call->event); 1298 } 1299 return ret; 1300 } 1301 1302 static int unregister_kprobe_event(struct trace_kprobe *tk) 1303 { 1304 int ret; 1305 1306 /* tp->event is unregistered in trace_remove_event_call() */ 1307 ret = trace_remove_event_call(&tk->tp.call); 1308 if (!ret) 1309 kfree(tk->tp.call.print_fmt); 1310 return ret; 1311 } 1312 1313 /* Make a debugfs interface for controlling probe points */ 1314 static __init int init_kprobe_trace(void) 1315 { 1316 struct dentry *d_tracer; 1317 struct dentry *entry; 1318 1319 if (register_module_notifier(&trace_kprobe_module_nb)) 1320 return -EINVAL; 1321 1322 d_tracer = tracing_init_dentry(); 1323 if (!d_tracer) 1324 return 0; 1325 1326 entry = debugfs_create_file("kprobe_events", 0644, d_tracer, 1327 NULL, &kprobe_events_ops); 1328 1329 /* Event list interface */ 1330 if (!entry) 1331 pr_warning("Could not create debugfs " 1332 "'kprobe_events' entry\n"); 1333 1334 /* Profile interface */ 1335 entry = debugfs_create_file("kprobe_profile", 0444, d_tracer, 1336 NULL, &kprobe_profile_ops); 1337 1338 if (!entry) 1339 pr_warning("Could not create debugfs " 1340 "'kprobe_profile' entry\n"); 1341 return 0; 1342 } 1343 fs_initcall(init_kprobe_trace); 1344 1345 1346 #ifdef CONFIG_FTRACE_STARTUP_TEST 1347 1348 /* 1349 * The "__used" keeps gcc from removing the function symbol 1350 * from the kallsyms table. 1351 */ 1352 static __used int kprobe_trace_selftest_target(int a1, int a2, int a3, 1353 int a4, int a5, int a6) 1354 { 1355 return a1 + a2 + a3 + a4 + a5 + a6; 1356 } 1357 1358 static struct ftrace_event_file * 1359 find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) 1360 { 1361 struct ftrace_event_file *file; 1362 1363 list_for_each_entry(file, &tr->events, list) 1364 if (file->event_call == &tk->tp.call) 1365 return file; 1366 1367 return NULL; 1368 } 1369 1370 /* 1371 * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this 1372 * stage, we can do this lockless. 1373 */ 1374 static __init int kprobe_trace_self_tests_init(void) 1375 { 1376 int ret, warn = 0; 1377 int (*target)(int, int, int, int, int, int); 1378 struct trace_kprobe *tk; 1379 struct ftrace_event_file *file; 1380 1381 if (tracing_is_disabled()) 1382 return -ENODEV; 1383 1384 target = kprobe_trace_selftest_target; 1385 1386 pr_info("Testing kprobe tracing: "); 1387 1388 ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target " 1389 "$stack $stack0 +0($stack)", 1390 create_trace_kprobe); 1391 if (WARN_ON_ONCE(ret)) { 1392 pr_warn("error on probing function entry.\n"); 1393 warn++; 1394 } else { 1395 /* Enable trace point */ 1396 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); 1397 if (WARN_ON_ONCE(tk == NULL)) { 1398 pr_warn("error on getting new probe.\n"); 1399 warn++; 1400 } else { 1401 file = find_trace_probe_file(tk, top_trace_array()); 1402 if (WARN_ON_ONCE(file == NULL)) { 1403 pr_warn("error on getting probe file.\n"); 1404 warn++; 1405 } else 1406 enable_trace_kprobe(tk, file); 1407 } 1408 } 1409 1410 ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target " 1411 "$retval", create_trace_kprobe); 1412 if (WARN_ON_ONCE(ret)) { 1413 pr_warn("error on probing function return.\n"); 1414 warn++; 1415 } else { 1416 /* Enable trace point */ 1417 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); 1418 if (WARN_ON_ONCE(tk == NULL)) { 1419 pr_warn("error on getting 2nd new probe.\n"); 1420 warn++; 1421 } else { 1422 file = find_trace_probe_file(tk, top_trace_array()); 1423 if (WARN_ON_ONCE(file == NULL)) { 1424 pr_warn("error on getting probe file.\n"); 1425 warn++; 1426 } else 1427 enable_trace_kprobe(tk, file); 1428 } 1429 } 1430 1431 if (warn) 1432 goto end; 1433 1434 ret = target(1, 2, 3, 4, 5, 6); 1435 1436 /* Disable trace points before removing it */ 1437 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); 1438 if (WARN_ON_ONCE(tk == NULL)) { 1439 pr_warn("error on getting test probe.\n"); 1440 warn++; 1441 } else { 1442 file = find_trace_probe_file(tk, top_trace_array()); 1443 if (WARN_ON_ONCE(file == NULL)) { 1444 pr_warn("error on getting probe file.\n"); 1445 warn++; 1446 } else 1447 disable_trace_kprobe(tk, file); 1448 } 1449 1450 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); 1451 if (WARN_ON_ONCE(tk == NULL)) { 1452 pr_warn("error on getting 2nd test probe.\n"); 1453 warn++; 1454 } else { 1455 file = find_trace_probe_file(tk, top_trace_array()); 1456 if (WARN_ON_ONCE(file == NULL)) { 1457 pr_warn("error on getting probe file.\n"); 1458 warn++; 1459 } else 1460 disable_trace_kprobe(tk, file); 1461 } 1462 1463 ret = traceprobe_command("-:testprobe", create_trace_kprobe); 1464 if (WARN_ON_ONCE(ret)) { 1465 pr_warn("error on deleting a probe.\n"); 1466 warn++; 1467 } 1468 1469 ret = traceprobe_command("-:testprobe2", create_trace_kprobe); 1470 if (WARN_ON_ONCE(ret)) { 1471 pr_warn("error on deleting a probe.\n"); 1472 warn++; 1473 } 1474 1475 end: 1476 release_all_trace_kprobes(); 1477 if (warn) 1478 pr_cont("NG: Some tests are failed. Please check them.\n"); 1479 else 1480 pr_cont("OK\n"); 1481 return 0; 1482 } 1483 1484 late_initcall(kprobe_trace_self_tests_init); 1485 1486 #endif 1487