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 ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0), 257 ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0), 258 ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0), 259 ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0), 260 261 ASSIGN_FETCH_TYPE_END 262 }; 263 264 /* 265 * Allocate new trace_probe and initialize it (including kprobes). 266 */ 267 static struct trace_kprobe *alloc_trace_kprobe(const char *group, 268 const char *event, 269 void *addr, 270 const char *symbol, 271 unsigned long offs, 272 int nargs, bool is_return) 273 { 274 struct trace_kprobe *tk; 275 int ret = -ENOMEM; 276 277 tk = kzalloc(SIZEOF_TRACE_KPROBE(nargs), GFP_KERNEL); 278 if (!tk) 279 return ERR_PTR(ret); 280 281 tk->nhit = alloc_percpu(unsigned long); 282 if (!tk->nhit) 283 goto error; 284 285 if (symbol) { 286 tk->symbol = kstrdup(symbol, GFP_KERNEL); 287 if (!tk->symbol) 288 goto error; 289 tk->rp.kp.symbol_name = tk->symbol; 290 tk->rp.kp.offset = offs; 291 } else 292 tk->rp.kp.addr = addr; 293 294 if (is_return) 295 tk->rp.handler = kretprobe_dispatcher; 296 else 297 tk->rp.kp.pre_handler = kprobe_dispatcher; 298 299 if (!event || !is_good_name(event)) { 300 ret = -EINVAL; 301 goto error; 302 } 303 304 tk->tp.call.class = &tk->tp.class; 305 tk->tp.call.name = kstrdup(event, GFP_KERNEL); 306 if (!tk->tp.call.name) 307 goto error; 308 309 if (!group || !is_good_name(group)) { 310 ret = -EINVAL; 311 goto error; 312 } 313 314 tk->tp.class.system = kstrdup(group, GFP_KERNEL); 315 if (!tk->tp.class.system) 316 goto error; 317 318 INIT_LIST_HEAD(&tk->list); 319 INIT_LIST_HEAD(&tk->tp.files); 320 return tk; 321 error: 322 kfree(tk->tp.call.name); 323 kfree(tk->symbol); 324 free_percpu(tk->nhit); 325 kfree(tk); 326 return ERR_PTR(ret); 327 } 328 329 static void free_trace_kprobe(struct trace_kprobe *tk) 330 { 331 int i; 332 333 for (i = 0; i < tk->tp.nr_args; i++) 334 traceprobe_free_probe_arg(&tk->tp.args[i]); 335 336 kfree(tk->tp.call.class->system); 337 kfree(tk->tp.call.name); 338 kfree(tk->symbol); 339 free_percpu(tk->nhit); 340 kfree(tk); 341 } 342 343 static struct trace_kprobe *find_trace_kprobe(const char *event, 344 const char *group) 345 { 346 struct trace_kprobe *tk; 347 348 list_for_each_entry(tk, &probe_list, list) 349 if (strcmp(trace_event_name(&tk->tp.call), event) == 0 && 350 strcmp(tk->tp.call.class->system, group) == 0) 351 return tk; 352 return NULL; 353 } 354 355 /* 356 * Enable trace_probe 357 * if the file is NULL, enable "perf" handler, or enable "trace" handler. 358 */ 359 static int 360 enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) 361 { 362 int ret = 0; 363 364 if (file) { 365 struct event_file_link *link; 366 367 link = kmalloc(sizeof(*link), GFP_KERNEL); 368 if (!link) { 369 ret = -ENOMEM; 370 goto out; 371 } 372 373 link->file = file; 374 list_add_tail_rcu(&link->list, &tk->tp.files); 375 376 tk->tp.flags |= TP_FLAG_TRACE; 377 } else 378 tk->tp.flags |= TP_FLAG_PROFILE; 379 380 if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) { 381 if (trace_kprobe_is_return(tk)) 382 ret = enable_kretprobe(&tk->rp); 383 else 384 ret = enable_kprobe(&tk->rp.kp); 385 } 386 out: 387 return ret; 388 } 389 390 /* 391 * Disable trace_probe 392 * if the file is NULL, disable "perf" handler, or disable "trace" handler. 393 */ 394 static int 395 disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) 396 { 397 struct event_file_link *link = NULL; 398 int wait = 0; 399 int ret = 0; 400 401 if (file) { 402 link = find_event_file_link(&tk->tp, file); 403 if (!link) { 404 ret = -EINVAL; 405 goto out; 406 } 407 408 list_del_rcu(&link->list); 409 wait = 1; 410 if (!list_empty(&tk->tp.files)) 411 goto out; 412 413 tk->tp.flags &= ~TP_FLAG_TRACE; 414 } else 415 tk->tp.flags &= ~TP_FLAG_PROFILE; 416 417 if (!trace_probe_is_enabled(&tk->tp) && trace_probe_is_registered(&tk->tp)) { 418 if (trace_kprobe_is_return(tk)) 419 disable_kretprobe(&tk->rp); 420 else 421 disable_kprobe(&tk->rp.kp); 422 wait = 1; 423 } 424 out: 425 if (wait) { 426 /* 427 * Synchronize with kprobe_trace_func/kretprobe_trace_func 428 * to ensure disabled (all running handlers are finished). 429 * This is not only for kfree(), but also the caller, 430 * trace_remove_event_call() supposes it for releasing 431 * event_call related objects, which will be accessed in 432 * the kprobe_trace_func/kretprobe_trace_func. 433 */ 434 synchronize_sched(); 435 kfree(link); /* Ignored if link == NULL */ 436 } 437 438 return ret; 439 } 440 441 /* Internal register function - just handle k*probes and flags */ 442 static int __register_trace_kprobe(struct trace_kprobe *tk) 443 { 444 int i, ret; 445 446 if (trace_probe_is_registered(&tk->tp)) 447 return -EINVAL; 448 449 for (i = 0; i < tk->tp.nr_args; i++) 450 traceprobe_update_arg(&tk->tp.args[i]); 451 452 /* Set/clear disabled flag according to tp->flag */ 453 if (trace_probe_is_enabled(&tk->tp)) 454 tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED; 455 else 456 tk->rp.kp.flags |= KPROBE_FLAG_DISABLED; 457 458 if (trace_kprobe_is_return(tk)) 459 ret = register_kretprobe(&tk->rp); 460 else 461 ret = register_kprobe(&tk->rp.kp); 462 463 if (ret == 0) 464 tk->tp.flags |= TP_FLAG_REGISTERED; 465 else { 466 pr_warn("Could not insert probe at %s+%lu: %d\n", 467 trace_kprobe_symbol(tk), trace_kprobe_offset(tk), ret); 468 if (ret == -ENOENT && trace_kprobe_is_on_module(tk)) { 469 pr_warn("This probe might be able to register after target module is loaded. Continue.\n"); 470 ret = 0; 471 } else if (ret == -EILSEQ) { 472 pr_warn("Probing address(0x%p) is not an instruction boundary.\n", 473 tk->rp.kp.addr); 474 ret = -EINVAL; 475 } 476 } 477 478 return ret; 479 } 480 481 /* Internal unregister function - just handle k*probes and flags */ 482 static void __unregister_trace_kprobe(struct trace_kprobe *tk) 483 { 484 if (trace_probe_is_registered(&tk->tp)) { 485 if (trace_kprobe_is_return(tk)) 486 unregister_kretprobe(&tk->rp); 487 else 488 unregister_kprobe(&tk->rp.kp); 489 tk->tp.flags &= ~TP_FLAG_REGISTERED; 490 /* Cleanup kprobe for reuse */ 491 if (tk->rp.kp.symbol_name) 492 tk->rp.kp.addr = NULL; 493 } 494 } 495 496 /* Unregister a trace_probe and probe_event: call with locking probe_lock */ 497 static int unregister_trace_kprobe(struct trace_kprobe *tk) 498 { 499 /* Enabled event can not be unregistered */ 500 if (trace_probe_is_enabled(&tk->tp)) 501 return -EBUSY; 502 503 /* Will fail if probe is being used by ftrace or perf */ 504 if (unregister_kprobe_event(tk)) 505 return -EBUSY; 506 507 __unregister_trace_kprobe(tk); 508 list_del(&tk->list); 509 510 return 0; 511 } 512 513 /* Register a trace_probe and probe_event */ 514 static int register_trace_kprobe(struct trace_kprobe *tk) 515 { 516 struct trace_kprobe *old_tk; 517 int ret; 518 519 mutex_lock(&probe_lock); 520 521 /* Delete old (same name) event if exist */ 522 old_tk = find_trace_kprobe(trace_event_name(&tk->tp.call), 523 tk->tp.call.class->system); 524 if (old_tk) { 525 ret = unregister_trace_kprobe(old_tk); 526 if (ret < 0) 527 goto end; 528 free_trace_kprobe(old_tk); 529 } 530 531 /* Register new event */ 532 ret = register_kprobe_event(tk); 533 if (ret) { 534 pr_warn("Failed to register probe event(%d)\n", ret); 535 goto end; 536 } 537 538 /* Register k*probe */ 539 ret = __register_trace_kprobe(tk); 540 if (ret < 0) 541 unregister_kprobe_event(tk); 542 else 543 list_add_tail(&tk->list, &probe_list); 544 545 end: 546 mutex_unlock(&probe_lock); 547 return ret; 548 } 549 550 /* Module notifier call back, checking event on the module */ 551 static int trace_kprobe_module_callback(struct notifier_block *nb, 552 unsigned long val, void *data) 553 { 554 struct module *mod = data; 555 struct trace_kprobe *tk; 556 int ret; 557 558 if (val != MODULE_STATE_COMING) 559 return NOTIFY_DONE; 560 561 /* Update probes on coming module */ 562 mutex_lock(&probe_lock); 563 list_for_each_entry(tk, &probe_list, list) { 564 if (trace_kprobe_within_module(tk, mod)) { 565 /* Don't need to check busy - this should have gone. */ 566 __unregister_trace_kprobe(tk); 567 ret = __register_trace_kprobe(tk); 568 if (ret) 569 pr_warn("Failed to re-register probe %s on %s: %d\n", 570 trace_event_name(&tk->tp.call), 571 mod->name, ret); 572 } 573 } 574 mutex_unlock(&probe_lock); 575 576 return NOTIFY_DONE; 577 } 578 579 static struct notifier_block trace_kprobe_module_nb = { 580 .notifier_call = trace_kprobe_module_callback, 581 .priority = 1 /* Invoked after kprobe module callback */ 582 }; 583 584 static int create_trace_kprobe(int argc, char **argv) 585 { 586 /* 587 * Argument syntax: 588 * - Add kprobe: p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS] 589 * - Add kretprobe: r[:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS] 590 * Fetch args: 591 * $retval : fetch return value 592 * $stack : fetch stack address 593 * $stackN : fetch Nth of stack (N:0-) 594 * $comm : fetch current task comm 595 * @ADDR : fetch memory at ADDR (ADDR should be in kernel) 596 * @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol) 597 * %REG : fetch register REG 598 * Dereferencing memory fetch: 599 * +|-offs(ARG) : fetch memory at ARG +|- offs address. 600 * Alias name of args: 601 * NAME=FETCHARG : set NAME as alias of FETCHARG. 602 * Type of args: 603 * FETCHARG:TYPE : use TYPE instead of unsigned long. 604 */ 605 struct trace_kprobe *tk; 606 int i, ret = 0; 607 bool is_return = false, is_delete = false; 608 char *symbol = NULL, *event = NULL, *group = NULL; 609 char *arg; 610 unsigned long offset = 0; 611 void *addr = NULL; 612 char buf[MAX_EVENT_NAME_LEN]; 613 614 /* argc must be >= 1 */ 615 if (argv[0][0] == 'p') 616 is_return = false; 617 else if (argv[0][0] == 'r') 618 is_return = true; 619 else if (argv[0][0] == '-') 620 is_delete = true; 621 else { 622 pr_info("Probe definition must be started with 'p', 'r' or" 623 " '-'.\n"); 624 return -EINVAL; 625 } 626 627 if (argv[0][1] == ':') { 628 event = &argv[0][2]; 629 if (strchr(event, '/')) { 630 group = event; 631 event = strchr(group, '/') + 1; 632 event[-1] = '\0'; 633 if (strlen(group) == 0) { 634 pr_info("Group name is not specified\n"); 635 return -EINVAL; 636 } 637 } 638 if (strlen(event) == 0) { 639 pr_info("Event name is not specified\n"); 640 return -EINVAL; 641 } 642 } 643 if (!group) 644 group = KPROBE_EVENT_SYSTEM; 645 646 if (is_delete) { 647 if (!event) { 648 pr_info("Delete command needs an event name.\n"); 649 return -EINVAL; 650 } 651 mutex_lock(&probe_lock); 652 tk = find_trace_kprobe(event, group); 653 if (!tk) { 654 mutex_unlock(&probe_lock); 655 pr_info("Event %s/%s doesn't exist.\n", group, event); 656 return -ENOENT; 657 } 658 /* delete an event */ 659 ret = unregister_trace_kprobe(tk); 660 if (ret == 0) 661 free_trace_kprobe(tk); 662 mutex_unlock(&probe_lock); 663 return ret; 664 } 665 666 if (argc < 2) { 667 pr_info("Probe point is not specified.\n"); 668 return -EINVAL; 669 } 670 if (isdigit(argv[1][0])) { 671 if (is_return) { 672 pr_info("Return probe point must be a symbol.\n"); 673 return -EINVAL; 674 } 675 /* an address specified */ 676 ret = kstrtoul(&argv[1][0], 0, (unsigned long *)&addr); 677 if (ret) { 678 pr_info("Failed to parse address.\n"); 679 return ret; 680 } 681 } else { 682 /* a symbol specified */ 683 symbol = argv[1]; 684 /* TODO: support .init module functions */ 685 ret = traceprobe_split_symbol_offset(symbol, &offset); 686 if (ret) { 687 pr_info("Failed to parse symbol.\n"); 688 return ret; 689 } 690 if (offset && is_return) { 691 pr_info("Return probe must be used without offset.\n"); 692 return -EINVAL; 693 } 694 } 695 argc -= 2; argv += 2; 696 697 /* setup a probe */ 698 if (!event) { 699 /* Make a new event name */ 700 if (symbol) 701 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld", 702 is_return ? 'r' : 'p', symbol, offset); 703 else 704 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_0x%p", 705 is_return ? 'r' : 'p', addr); 706 event = buf; 707 } 708 tk = alloc_trace_kprobe(group, event, addr, symbol, offset, argc, 709 is_return); 710 if (IS_ERR(tk)) { 711 pr_info("Failed to allocate trace_probe.(%d)\n", 712 (int)PTR_ERR(tk)); 713 return PTR_ERR(tk); 714 } 715 716 /* parse arguments */ 717 ret = 0; 718 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { 719 struct probe_arg *parg = &tk->tp.args[i]; 720 721 /* Increment count for freeing args in error case */ 722 tk->tp.nr_args++; 723 724 /* Parse argument name */ 725 arg = strchr(argv[i], '='); 726 if (arg) { 727 *arg++ = '\0'; 728 parg->name = kstrdup(argv[i], GFP_KERNEL); 729 } else { 730 arg = argv[i]; 731 /* If argument name is omitted, set "argN" */ 732 snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1); 733 parg->name = kstrdup(buf, GFP_KERNEL); 734 } 735 736 if (!parg->name) { 737 pr_info("Failed to allocate argument[%d] name.\n", i); 738 ret = -ENOMEM; 739 goto error; 740 } 741 742 if (!is_good_name(parg->name)) { 743 pr_info("Invalid argument[%d] name: %s\n", 744 i, parg->name); 745 ret = -EINVAL; 746 goto error; 747 } 748 749 if (traceprobe_conflict_field_name(parg->name, 750 tk->tp.args, i)) { 751 pr_info("Argument[%d] name '%s' conflicts with " 752 "another field.\n", i, argv[i]); 753 ret = -EINVAL; 754 goto error; 755 } 756 757 /* Parse fetch argument */ 758 ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg, 759 is_return, true, 760 kprobes_fetch_type_table); 761 if (ret) { 762 pr_info("Parse error at argument[%d]. (%d)\n", i, ret); 763 goto error; 764 } 765 } 766 767 ret = register_trace_kprobe(tk); 768 if (ret) 769 goto error; 770 return 0; 771 772 error: 773 free_trace_kprobe(tk); 774 return ret; 775 } 776 777 static int release_all_trace_kprobes(void) 778 { 779 struct trace_kprobe *tk; 780 int ret = 0; 781 782 mutex_lock(&probe_lock); 783 /* Ensure no probe is in use. */ 784 list_for_each_entry(tk, &probe_list, list) 785 if (trace_probe_is_enabled(&tk->tp)) { 786 ret = -EBUSY; 787 goto end; 788 } 789 /* TODO: Use batch unregistration */ 790 while (!list_empty(&probe_list)) { 791 tk = list_entry(probe_list.next, struct trace_kprobe, list); 792 ret = unregister_trace_kprobe(tk); 793 if (ret) 794 goto end; 795 free_trace_kprobe(tk); 796 } 797 798 end: 799 mutex_unlock(&probe_lock); 800 801 return ret; 802 } 803 804 /* Probes listing interfaces */ 805 static void *probes_seq_start(struct seq_file *m, loff_t *pos) 806 { 807 mutex_lock(&probe_lock); 808 return seq_list_start(&probe_list, *pos); 809 } 810 811 static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos) 812 { 813 return seq_list_next(v, &probe_list, pos); 814 } 815 816 static void probes_seq_stop(struct seq_file *m, void *v) 817 { 818 mutex_unlock(&probe_lock); 819 } 820 821 static int probes_seq_show(struct seq_file *m, void *v) 822 { 823 struct trace_kprobe *tk = v; 824 int i; 825 826 seq_putc(m, trace_kprobe_is_return(tk) ? 'r' : 'p'); 827 seq_printf(m, ":%s/%s", tk->tp.call.class->system, 828 trace_event_name(&tk->tp.call)); 829 830 if (!tk->symbol) 831 seq_printf(m, " 0x%p", tk->rp.kp.addr); 832 else if (tk->rp.kp.offset) 833 seq_printf(m, " %s+%u", trace_kprobe_symbol(tk), 834 tk->rp.kp.offset); 835 else 836 seq_printf(m, " %s", trace_kprobe_symbol(tk)); 837 838 for (i = 0; i < tk->tp.nr_args; i++) 839 seq_printf(m, " %s=%s", tk->tp.args[i].name, tk->tp.args[i].comm); 840 seq_putc(m, '\n'); 841 842 return 0; 843 } 844 845 static const struct seq_operations probes_seq_op = { 846 .start = probes_seq_start, 847 .next = probes_seq_next, 848 .stop = probes_seq_stop, 849 .show = probes_seq_show 850 }; 851 852 static int probes_open(struct inode *inode, struct file *file) 853 { 854 int ret; 855 856 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { 857 ret = release_all_trace_kprobes(); 858 if (ret < 0) 859 return ret; 860 } 861 862 return seq_open(file, &probes_seq_op); 863 } 864 865 static ssize_t probes_write(struct file *file, const char __user *buffer, 866 size_t count, loff_t *ppos) 867 { 868 return traceprobe_probes_write(file, buffer, count, ppos, 869 create_trace_kprobe); 870 } 871 872 static const struct file_operations kprobe_events_ops = { 873 .owner = THIS_MODULE, 874 .open = probes_open, 875 .read = seq_read, 876 .llseek = seq_lseek, 877 .release = seq_release, 878 .write = probes_write, 879 }; 880 881 /* Probes profiling interfaces */ 882 static int probes_profile_seq_show(struct seq_file *m, void *v) 883 { 884 struct trace_kprobe *tk = v; 885 unsigned long nhit = 0; 886 int cpu; 887 888 for_each_possible_cpu(cpu) 889 nhit += *per_cpu_ptr(tk->nhit, cpu); 890 891 seq_printf(m, " %-44s %15lu %15lu\n", 892 trace_event_name(&tk->tp.call), nhit, 893 tk->rp.kp.nmissed); 894 895 return 0; 896 } 897 898 static const struct seq_operations profile_seq_op = { 899 .start = probes_seq_start, 900 .next = probes_seq_next, 901 .stop = probes_seq_stop, 902 .show = probes_profile_seq_show 903 }; 904 905 static int profile_open(struct inode *inode, struct file *file) 906 { 907 return seq_open(file, &profile_seq_op); 908 } 909 910 static const struct file_operations kprobe_profile_ops = { 911 .owner = THIS_MODULE, 912 .open = profile_open, 913 .read = seq_read, 914 .llseek = seq_lseek, 915 .release = seq_release, 916 }; 917 918 /* Kprobe handler */ 919 static nokprobe_inline void 920 __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, 921 struct trace_event_file *trace_file) 922 { 923 struct kprobe_trace_entry_head *entry; 924 struct ring_buffer_event *event; 925 struct ring_buffer *buffer; 926 int size, dsize, pc; 927 unsigned long irq_flags; 928 struct trace_event_call *call = &tk->tp.call; 929 930 WARN_ON(call != trace_file->event_call); 931 932 if (trace_trigger_soft_disabled(trace_file)) 933 return; 934 935 local_save_flags(irq_flags); 936 pc = preempt_count(); 937 938 dsize = __get_data_size(&tk->tp, regs); 939 size = sizeof(*entry) + tk->tp.size + dsize; 940 941 event = trace_event_buffer_lock_reserve(&buffer, trace_file, 942 call->event.type, 943 size, irq_flags, pc); 944 if (!event) 945 return; 946 947 entry = ring_buffer_event_data(event); 948 entry->ip = (unsigned long)tk->rp.kp.addr; 949 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); 950 951 event_trigger_unlock_commit_regs(trace_file, buffer, event, 952 entry, irq_flags, pc, regs); 953 } 954 955 static void 956 kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) 957 { 958 struct event_file_link *link; 959 960 list_for_each_entry_rcu(link, &tk->tp.files, list) 961 __kprobe_trace_func(tk, regs, link->file); 962 } 963 NOKPROBE_SYMBOL(kprobe_trace_func); 964 965 /* Kretprobe handler */ 966 static nokprobe_inline void 967 __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, 968 struct pt_regs *regs, 969 struct trace_event_file *trace_file) 970 { 971 struct kretprobe_trace_entry_head *entry; 972 struct ring_buffer_event *event; 973 struct ring_buffer *buffer; 974 int size, pc, dsize; 975 unsigned long irq_flags; 976 struct trace_event_call *call = &tk->tp.call; 977 978 WARN_ON(call != trace_file->event_call); 979 980 if (trace_trigger_soft_disabled(trace_file)) 981 return; 982 983 local_save_flags(irq_flags); 984 pc = preempt_count(); 985 986 dsize = __get_data_size(&tk->tp, regs); 987 size = sizeof(*entry) + tk->tp.size + dsize; 988 989 event = trace_event_buffer_lock_reserve(&buffer, trace_file, 990 call->event.type, 991 size, irq_flags, pc); 992 if (!event) 993 return; 994 995 entry = ring_buffer_event_data(event); 996 entry->func = (unsigned long)tk->rp.kp.addr; 997 entry->ret_ip = (unsigned long)ri->ret_addr; 998 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); 999 1000 event_trigger_unlock_commit_regs(trace_file, buffer, event, 1001 entry, irq_flags, pc, regs); 1002 } 1003 1004 static void 1005 kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, 1006 struct pt_regs *regs) 1007 { 1008 struct event_file_link *link; 1009 1010 list_for_each_entry_rcu(link, &tk->tp.files, list) 1011 __kretprobe_trace_func(tk, ri, regs, link->file); 1012 } 1013 NOKPROBE_SYMBOL(kretprobe_trace_func); 1014 1015 /* Event entry printers */ 1016 static enum print_line_t 1017 print_kprobe_event(struct trace_iterator *iter, int flags, 1018 struct trace_event *event) 1019 { 1020 struct kprobe_trace_entry_head *field; 1021 struct trace_seq *s = &iter->seq; 1022 struct trace_probe *tp; 1023 u8 *data; 1024 int i; 1025 1026 field = (struct kprobe_trace_entry_head *)iter->ent; 1027 tp = container_of(event, struct trace_probe, call.event); 1028 1029 trace_seq_printf(s, "%s: (", trace_event_name(&tp->call)); 1030 1031 if (!seq_print_ip_sym(s, field->ip, flags | TRACE_ITER_SYM_OFFSET)) 1032 goto out; 1033 1034 trace_seq_putc(s, ')'); 1035 1036 data = (u8 *)&field[1]; 1037 for (i = 0; i < tp->nr_args; i++) 1038 if (!tp->args[i].type->print(s, tp->args[i].name, 1039 data + tp->args[i].offset, field)) 1040 goto out; 1041 1042 trace_seq_putc(s, '\n'); 1043 out: 1044 return trace_handle_return(s); 1045 } 1046 1047 static enum print_line_t 1048 print_kretprobe_event(struct trace_iterator *iter, int flags, 1049 struct trace_event *event) 1050 { 1051 struct kretprobe_trace_entry_head *field; 1052 struct trace_seq *s = &iter->seq; 1053 struct trace_probe *tp; 1054 u8 *data; 1055 int i; 1056 1057 field = (struct kretprobe_trace_entry_head *)iter->ent; 1058 tp = container_of(event, struct trace_probe, call.event); 1059 1060 trace_seq_printf(s, "%s: (", trace_event_name(&tp->call)); 1061 1062 if (!seq_print_ip_sym(s, field->ret_ip, flags | TRACE_ITER_SYM_OFFSET)) 1063 goto out; 1064 1065 trace_seq_puts(s, " <- "); 1066 1067 if (!seq_print_ip_sym(s, field->func, flags & ~TRACE_ITER_SYM_OFFSET)) 1068 goto out; 1069 1070 trace_seq_putc(s, ')'); 1071 1072 data = (u8 *)&field[1]; 1073 for (i = 0; i < tp->nr_args; i++) 1074 if (!tp->args[i].type->print(s, tp->args[i].name, 1075 data + tp->args[i].offset, field)) 1076 goto out; 1077 1078 trace_seq_putc(s, '\n'); 1079 1080 out: 1081 return trace_handle_return(s); 1082 } 1083 1084 1085 static int kprobe_event_define_fields(struct trace_event_call *event_call) 1086 { 1087 int ret, i; 1088 struct kprobe_trace_entry_head field; 1089 struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data; 1090 1091 DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0); 1092 /* Set argument names as fields */ 1093 for (i = 0; i < tk->tp.nr_args; i++) { 1094 struct probe_arg *parg = &tk->tp.args[i]; 1095 1096 ret = trace_define_field(event_call, parg->type->fmttype, 1097 parg->name, 1098 sizeof(field) + parg->offset, 1099 parg->type->size, 1100 parg->type->is_signed, 1101 FILTER_OTHER); 1102 if (ret) 1103 return ret; 1104 } 1105 return 0; 1106 } 1107 1108 static int kretprobe_event_define_fields(struct trace_event_call *event_call) 1109 { 1110 int ret, i; 1111 struct kretprobe_trace_entry_head field; 1112 struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data; 1113 1114 DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0); 1115 DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0); 1116 /* Set argument names as fields */ 1117 for (i = 0; i < tk->tp.nr_args; i++) { 1118 struct probe_arg *parg = &tk->tp.args[i]; 1119 1120 ret = trace_define_field(event_call, parg->type->fmttype, 1121 parg->name, 1122 sizeof(field) + parg->offset, 1123 parg->type->size, 1124 parg->type->is_signed, 1125 FILTER_OTHER); 1126 if (ret) 1127 return ret; 1128 } 1129 return 0; 1130 } 1131 1132 #ifdef CONFIG_PERF_EVENTS 1133 1134 /* Kprobe profile handler */ 1135 static void 1136 kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) 1137 { 1138 struct trace_event_call *call = &tk->tp.call; 1139 struct bpf_prog *prog = call->prog; 1140 struct kprobe_trace_entry_head *entry; 1141 struct hlist_head *head; 1142 int size, __size, dsize; 1143 int rctx; 1144 1145 if (prog && !trace_call_bpf(prog, regs)) 1146 return; 1147 1148 head = this_cpu_ptr(call->perf_events); 1149 if (hlist_empty(head)) 1150 return; 1151 1152 dsize = __get_data_size(&tk->tp, regs); 1153 __size = sizeof(*entry) + tk->tp.size + dsize; 1154 size = ALIGN(__size + sizeof(u32), sizeof(u64)); 1155 size -= sizeof(u32); 1156 1157 entry = perf_trace_buf_alloc(size, NULL, &rctx); 1158 if (!entry) 1159 return; 1160 1161 entry->ip = (unsigned long)tk->rp.kp.addr; 1162 memset(&entry[1], 0, dsize); 1163 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); 1164 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, 1165 head, NULL); 1166 } 1167 NOKPROBE_SYMBOL(kprobe_perf_func); 1168 1169 /* Kretprobe profile handler */ 1170 static void 1171 kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, 1172 struct pt_regs *regs) 1173 { 1174 struct trace_event_call *call = &tk->tp.call; 1175 struct bpf_prog *prog = call->prog; 1176 struct kretprobe_trace_entry_head *entry; 1177 struct hlist_head *head; 1178 int size, __size, dsize; 1179 int rctx; 1180 1181 if (prog && !trace_call_bpf(prog, regs)) 1182 return; 1183 1184 head = this_cpu_ptr(call->perf_events); 1185 if (hlist_empty(head)) 1186 return; 1187 1188 dsize = __get_data_size(&tk->tp, regs); 1189 __size = sizeof(*entry) + tk->tp.size + dsize; 1190 size = ALIGN(__size + sizeof(u32), sizeof(u64)); 1191 size -= sizeof(u32); 1192 1193 entry = perf_trace_buf_alloc(size, NULL, &rctx); 1194 if (!entry) 1195 return; 1196 1197 entry->func = (unsigned long)tk->rp.kp.addr; 1198 entry->ret_ip = (unsigned long)ri->ret_addr; 1199 store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); 1200 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, 1201 head, NULL); 1202 } 1203 NOKPROBE_SYMBOL(kretprobe_perf_func); 1204 #endif /* CONFIG_PERF_EVENTS */ 1205 1206 /* 1207 * called by perf_trace_init() or __ftrace_set_clr_event() under event_mutex. 1208 * 1209 * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe 1210 * lockless, but we can't race with this __init function. 1211 */ 1212 static int kprobe_register(struct trace_event_call *event, 1213 enum trace_reg type, void *data) 1214 { 1215 struct trace_kprobe *tk = (struct trace_kprobe *)event->data; 1216 struct trace_event_file *file = data; 1217 1218 switch (type) { 1219 case TRACE_REG_REGISTER: 1220 return enable_trace_kprobe(tk, file); 1221 case TRACE_REG_UNREGISTER: 1222 return disable_trace_kprobe(tk, file); 1223 1224 #ifdef CONFIG_PERF_EVENTS 1225 case TRACE_REG_PERF_REGISTER: 1226 return enable_trace_kprobe(tk, NULL); 1227 case TRACE_REG_PERF_UNREGISTER: 1228 return disable_trace_kprobe(tk, NULL); 1229 case TRACE_REG_PERF_OPEN: 1230 case TRACE_REG_PERF_CLOSE: 1231 case TRACE_REG_PERF_ADD: 1232 case TRACE_REG_PERF_DEL: 1233 return 0; 1234 #endif 1235 } 1236 return 0; 1237 } 1238 1239 static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) 1240 { 1241 struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); 1242 1243 raw_cpu_inc(*tk->nhit); 1244 1245 if (tk->tp.flags & TP_FLAG_TRACE) 1246 kprobe_trace_func(tk, regs); 1247 #ifdef CONFIG_PERF_EVENTS 1248 if (tk->tp.flags & TP_FLAG_PROFILE) 1249 kprobe_perf_func(tk, regs); 1250 #endif 1251 return 0; /* We don't tweek kernel, so just return 0 */ 1252 } 1253 NOKPROBE_SYMBOL(kprobe_dispatcher); 1254 1255 static int 1256 kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) 1257 { 1258 struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp); 1259 1260 raw_cpu_inc(*tk->nhit); 1261 1262 if (tk->tp.flags & TP_FLAG_TRACE) 1263 kretprobe_trace_func(tk, ri, regs); 1264 #ifdef CONFIG_PERF_EVENTS 1265 if (tk->tp.flags & TP_FLAG_PROFILE) 1266 kretprobe_perf_func(tk, ri, regs); 1267 #endif 1268 return 0; /* We don't tweek kernel, so just return 0 */ 1269 } 1270 NOKPROBE_SYMBOL(kretprobe_dispatcher); 1271 1272 static struct trace_event_functions kretprobe_funcs = { 1273 .trace = print_kretprobe_event 1274 }; 1275 1276 static struct trace_event_functions kprobe_funcs = { 1277 .trace = print_kprobe_event 1278 }; 1279 1280 static int register_kprobe_event(struct trace_kprobe *tk) 1281 { 1282 struct trace_event_call *call = &tk->tp.call; 1283 int ret; 1284 1285 /* Initialize trace_event_call */ 1286 INIT_LIST_HEAD(&call->class->fields); 1287 if (trace_kprobe_is_return(tk)) { 1288 call->event.funcs = &kretprobe_funcs; 1289 call->class->define_fields = kretprobe_event_define_fields; 1290 } else { 1291 call->event.funcs = &kprobe_funcs; 1292 call->class->define_fields = kprobe_event_define_fields; 1293 } 1294 if (set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) 1295 return -ENOMEM; 1296 ret = register_trace_event(&call->event); 1297 if (!ret) { 1298 kfree(call->print_fmt); 1299 return -ENODEV; 1300 } 1301 call->flags = TRACE_EVENT_FL_KPROBE; 1302 call->class->reg = kprobe_register; 1303 call->data = tk; 1304 ret = trace_add_event_call(call); 1305 if (ret) { 1306 pr_info("Failed to register kprobe event: %s\n", 1307 trace_event_name(call)); 1308 kfree(call->print_fmt); 1309 unregister_trace_event(&call->event); 1310 } 1311 return ret; 1312 } 1313 1314 static int unregister_kprobe_event(struct trace_kprobe *tk) 1315 { 1316 int ret; 1317 1318 /* tp->event is unregistered in trace_remove_event_call() */ 1319 ret = trace_remove_event_call(&tk->tp.call); 1320 if (!ret) 1321 kfree(tk->tp.call.print_fmt); 1322 return ret; 1323 } 1324 1325 /* Make a tracefs interface for controlling probe points */ 1326 static __init int init_kprobe_trace(void) 1327 { 1328 struct dentry *d_tracer; 1329 struct dentry *entry; 1330 1331 if (register_module_notifier(&trace_kprobe_module_nb)) 1332 return -EINVAL; 1333 1334 d_tracer = tracing_init_dentry(); 1335 if (IS_ERR(d_tracer)) 1336 return 0; 1337 1338 entry = tracefs_create_file("kprobe_events", 0644, d_tracer, 1339 NULL, &kprobe_events_ops); 1340 1341 /* Event list interface */ 1342 if (!entry) 1343 pr_warn("Could not create tracefs 'kprobe_events' entry\n"); 1344 1345 /* Profile interface */ 1346 entry = tracefs_create_file("kprobe_profile", 0444, d_tracer, 1347 NULL, &kprobe_profile_ops); 1348 1349 if (!entry) 1350 pr_warn("Could not create tracefs 'kprobe_profile' entry\n"); 1351 return 0; 1352 } 1353 fs_initcall(init_kprobe_trace); 1354 1355 1356 #ifdef CONFIG_FTRACE_STARTUP_TEST 1357 1358 /* 1359 * The "__used" keeps gcc from removing the function symbol 1360 * from the kallsyms table. 1361 */ 1362 static __used int kprobe_trace_selftest_target(int a1, int a2, int a3, 1363 int a4, int a5, int a6) 1364 { 1365 return a1 + a2 + a3 + a4 + a5 + a6; 1366 } 1367 1368 static struct trace_event_file * 1369 find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr) 1370 { 1371 struct trace_event_file *file; 1372 1373 list_for_each_entry(file, &tr->events, list) 1374 if (file->event_call == &tk->tp.call) 1375 return file; 1376 1377 return NULL; 1378 } 1379 1380 /* 1381 * Nobody but us can call enable_trace_kprobe/disable_trace_kprobe at this 1382 * stage, we can do this lockless. 1383 */ 1384 static __init int kprobe_trace_self_tests_init(void) 1385 { 1386 int ret, warn = 0; 1387 int (*target)(int, int, int, int, int, int); 1388 struct trace_kprobe *tk; 1389 struct trace_event_file *file; 1390 1391 if (tracing_is_disabled()) 1392 return -ENODEV; 1393 1394 target = kprobe_trace_selftest_target; 1395 1396 pr_info("Testing kprobe tracing: "); 1397 1398 ret = traceprobe_command("p:testprobe kprobe_trace_selftest_target " 1399 "$stack $stack0 +0($stack)", 1400 create_trace_kprobe); 1401 if (WARN_ON_ONCE(ret)) { 1402 pr_warn("error on probing function entry.\n"); 1403 warn++; 1404 } else { 1405 /* Enable trace point */ 1406 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); 1407 if (WARN_ON_ONCE(tk == NULL)) { 1408 pr_warn("error on getting new probe.\n"); 1409 warn++; 1410 } else { 1411 file = find_trace_probe_file(tk, top_trace_array()); 1412 if (WARN_ON_ONCE(file == NULL)) { 1413 pr_warn("error on getting probe file.\n"); 1414 warn++; 1415 } else 1416 enable_trace_kprobe(tk, file); 1417 } 1418 } 1419 1420 ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target " 1421 "$retval", create_trace_kprobe); 1422 if (WARN_ON_ONCE(ret)) { 1423 pr_warn("error on probing function return.\n"); 1424 warn++; 1425 } else { 1426 /* Enable trace point */ 1427 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); 1428 if (WARN_ON_ONCE(tk == NULL)) { 1429 pr_warn("error on getting 2nd new probe.\n"); 1430 warn++; 1431 } else { 1432 file = find_trace_probe_file(tk, top_trace_array()); 1433 if (WARN_ON_ONCE(file == NULL)) { 1434 pr_warn("error on getting probe file.\n"); 1435 warn++; 1436 } else 1437 enable_trace_kprobe(tk, file); 1438 } 1439 } 1440 1441 if (warn) 1442 goto end; 1443 1444 ret = target(1, 2, 3, 4, 5, 6); 1445 1446 /* Disable trace points before removing it */ 1447 tk = find_trace_kprobe("testprobe", KPROBE_EVENT_SYSTEM); 1448 if (WARN_ON_ONCE(tk == NULL)) { 1449 pr_warn("error on getting test probe.\n"); 1450 warn++; 1451 } else { 1452 file = find_trace_probe_file(tk, top_trace_array()); 1453 if (WARN_ON_ONCE(file == NULL)) { 1454 pr_warn("error on getting probe file.\n"); 1455 warn++; 1456 } else 1457 disable_trace_kprobe(tk, file); 1458 } 1459 1460 tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM); 1461 if (WARN_ON_ONCE(tk == NULL)) { 1462 pr_warn("error on getting 2nd test probe.\n"); 1463 warn++; 1464 } else { 1465 file = find_trace_probe_file(tk, top_trace_array()); 1466 if (WARN_ON_ONCE(file == NULL)) { 1467 pr_warn("error on getting probe file.\n"); 1468 warn++; 1469 } else 1470 disable_trace_kprobe(tk, file); 1471 } 1472 1473 ret = traceprobe_command("-:testprobe", create_trace_kprobe); 1474 if (WARN_ON_ONCE(ret)) { 1475 pr_warn("error on deleting a probe.\n"); 1476 warn++; 1477 } 1478 1479 ret = traceprobe_command("-:testprobe2", create_trace_kprobe); 1480 if (WARN_ON_ONCE(ret)) { 1481 pr_warn("error on deleting a probe.\n"); 1482 warn++; 1483 } 1484 1485 end: 1486 release_all_trace_kprobes(); 1487 if (warn) 1488 pr_cont("NG: Some tests are failed. Please check them.\n"); 1489 else 1490 pr_cont("OK\n"); 1491 return 0; 1492 } 1493 1494 late_initcall(kprobe_trace_self_tests_init); 1495 1496 #endif 1497