1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * uprobes-based tracing events 4 * 5 * Copyright (C) IBM Corporation, 2010-2012 6 * Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com> 7 */ 8 #define pr_fmt(fmt) "trace_uprobe: " fmt 9 10 #include <linux/security.h> 11 #include <linux/ctype.h> 12 #include <linux/module.h> 13 #include <linux/uaccess.h> 14 #include <linux/uprobes.h> 15 #include <linux/namei.h> 16 #include <linux/string.h> 17 #include <linux/rculist.h> 18 19 #include "trace_dynevent.h" 20 #include "trace_probe.h" 21 #include "trace_probe_tmpl.h" 22 23 #define UPROBE_EVENT_SYSTEM "uprobes" 24 25 struct uprobe_trace_entry_head { 26 struct trace_entry ent; 27 unsigned long vaddr[]; 28 }; 29 30 #define SIZEOF_TRACE_ENTRY(is_return) \ 31 (sizeof(struct uprobe_trace_entry_head) + \ 32 sizeof(unsigned long) * (is_return ? 2 : 1)) 33 34 #define DATAOF_TRACE_ENTRY(entry, is_return) \ 35 ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return)) 36 37 static int trace_uprobe_create(const char *raw_command); 38 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev); 39 static int trace_uprobe_release(struct dyn_event *ev); 40 static bool trace_uprobe_is_busy(struct dyn_event *ev); 41 static bool trace_uprobe_match(const char *system, const char *event, 42 int argc, const char **argv, struct dyn_event *ev); 43 44 static struct dyn_event_operations trace_uprobe_ops = { 45 .create = trace_uprobe_create, 46 .show = trace_uprobe_show, 47 .is_busy = trace_uprobe_is_busy, 48 .free = trace_uprobe_release, 49 .match = trace_uprobe_match, 50 }; 51 52 /* 53 * uprobe event core functions 54 */ 55 struct trace_uprobe { 56 struct dyn_event devent; 57 struct uprobe_consumer consumer; 58 struct path path; 59 struct inode *inode; 60 char *filename; 61 unsigned long offset; 62 unsigned long ref_ctr_offset; 63 unsigned long nhit; 64 struct trace_probe tp; 65 }; 66 67 static bool is_trace_uprobe(struct dyn_event *ev) 68 { 69 return ev->ops == &trace_uprobe_ops; 70 } 71 72 static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev) 73 { 74 return container_of(ev, struct trace_uprobe, devent); 75 } 76 77 /** 78 * for_each_trace_uprobe - iterate over the trace_uprobe list 79 * @pos: the struct trace_uprobe * for each entry 80 * @dpos: the struct dyn_event * to use as a loop cursor 81 */ 82 #define for_each_trace_uprobe(pos, dpos) \ 83 for_each_dyn_event(dpos) \ 84 if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos))) 85 86 #define SIZEOF_TRACE_UPROBE(n) \ 87 (offsetof(struct trace_uprobe, tp.args) + \ 88 (sizeof(struct probe_arg) * (n))) 89 90 static int register_uprobe_event(struct trace_uprobe *tu); 91 static int unregister_uprobe_event(struct trace_uprobe *tu); 92 93 struct uprobe_dispatch_data { 94 struct trace_uprobe *tu; 95 unsigned long bp_addr; 96 }; 97 98 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs); 99 static int uretprobe_dispatcher(struct uprobe_consumer *con, 100 unsigned long func, struct pt_regs *regs); 101 102 #ifdef CONFIG_STACK_GROWSUP 103 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) 104 { 105 return addr - (n * sizeof(long)); 106 } 107 #else 108 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) 109 { 110 return addr + (n * sizeof(long)); 111 } 112 #endif 113 114 static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n) 115 { 116 unsigned long ret; 117 unsigned long addr = user_stack_pointer(regs); 118 119 addr = adjust_stack_addr(addr, n); 120 121 if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret))) 122 return 0; 123 124 return ret; 125 } 126 127 /* 128 * Uprobes-specific fetch functions 129 */ 130 static nokprobe_inline int 131 probe_mem_read(void *dest, void *src, size_t size) 132 { 133 void __user *vaddr = (void __force __user *)src; 134 135 return copy_from_user(dest, vaddr, size) ? -EFAULT : 0; 136 } 137 138 static nokprobe_inline int 139 probe_mem_read_user(void *dest, void *src, size_t size) 140 { 141 return probe_mem_read(dest, src, size); 142 } 143 144 /* 145 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max 146 * length and relative data location. 147 */ 148 static nokprobe_inline int 149 fetch_store_string(unsigned long addr, void *dest, void *base) 150 { 151 long ret; 152 u32 loc = *(u32 *)dest; 153 int maxlen = get_loc_len(loc); 154 u8 *dst = get_loc_data(dest, base); 155 void __user *src = (void __force __user *) addr; 156 157 if (unlikely(!maxlen)) 158 return -ENOMEM; 159 160 if (addr == FETCH_TOKEN_COMM) 161 ret = strlcpy(dst, current->comm, maxlen); 162 else 163 ret = strncpy_from_user(dst, src, maxlen); 164 if (ret >= 0) { 165 if (ret == maxlen) 166 dst[ret - 1] = '\0'; 167 else 168 /* 169 * Include the terminating null byte. In this case it 170 * was copied by strncpy_from_user but not accounted 171 * for in ret. 172 */ 173 ret++; 174 *(u32 *)dest = make_data_loc(ret, (void *)dst - base); 175 } 176 177 return ret; 178 } 179 180 static nokprobe_inline int 181 fetch_store_string_user(unsigned long addr, void *dest, void *base) 182 { 183 return fetch_store_string(addr, dest, base); 184 } 185 186 /* Return the length of string -- including null terminal byte */ 187 static nokprobe_inline int 188 fetch_store_strlen(unsigned long addr) 189 { 190 int len; 191 void __user *vaddr = (void __force __user *) addr; 192 193 if (addr == FETCH_TOKEN_COMM) 194 len = strlen(current->comm) + 1; 195 else 196 len = strnlen_user(vaddr, MAX_STRING_SIZE); 197 198 return (len > MAX_STRING_SIZE) ? 0 : len; 199 } 200 201 static nokprobe_inline int 202 fetch_store_strlen_user(unsigned long addr) 203 { 204 return fetch_store_strlen(addr); 205 } 206 207 static unsigned long translate_user_vaddr(unsigned long file_offset) 208 { 209 unsigned long base_addr; 210 struct uprobe_dispatch_data *udd; 211 212 udd = (void *) current->utask->vaddr; 213 214 base_addr = udd->bp_addr - udd->tu->offset; 215 return base_addr + file_offset; 216 } 217 218 /* Note that we don't verify it, since the code does not come from user space */ 219 static int 220 process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest, 221 void *base) 222 { 223 unsigned long val; 224 225 /* 1st stage: get value from context */ 226 switch (code->op) { 227 case FETCH_OP_REG: 228 val = regs_get_register(regs, code->param); 229 break; 230 case FETCH_OP_STACK: 231 val = get_user_stack_nth(regs, code->param); 232 break; 233 case FETCH_OP_STACKP: 234 val = user_stack_pointer(regs); 235 break; 236 case FETCH_OP_RETVAL: 237 val = regs_return_value(regs); 238 break; 239 case FETCH_OP_IMM: 240 val = code->immediate; 241 break; 242 case FETCH_OP_COMM: 243 val = FETCH_TOKEN_COMM; 244 break; 245 case FETCH_OP_DATA: 246 val = (unsigned long)code->data; 247 break; 248 case FETCH_OP_FOFFS: 249 val = translate_user_vaddr(code->immediate); 250 break; 251 default: 252 return -EILSEQ; 253 } 254 code++; 255 256 return process_fetch_insn_bottom(code, val, dest, base); 257 } 258 NOKPROBE_SYMBOL(process_fetch_insn) 259 260 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter) 261 { 262 rwlock_init(&filter->rwlock); 263 filter->nr_systemwide = 0; 264 INIT_LIST_HEAD(&filter->perf_events); 265 } 266 267 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter) 268 { 269 return !filter->nr_systemwide && list_empty(&filter->perf_events); 270 } 271 272 static inline bool is_ret_probe(struct trace_uprobe *tu) 273 { 274 return tu->consumer.ret_handler != NULL; 275 } 276 277 static bool trace_uprobe_is_busy(struct dyn_event *ev) 278 { 279 struct trace_uprobe *tu = to_trace_uprobe(ev); 280 281 return trace_probe_is_enabled(&tu->tp); 282 } 283 284 static bool trace_uprobe_match_command_head(struct trace_uprobe *tu, 285 int argc, const char **argv) 286 { 287 char buf[MAX_ARGSTR_LEN + 1]; 288 int len; 289 290 if (!argc) 291 return true; 292 293 len = strlen(tu->filename); 294 if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':') 295 return false; 296 297 if (tu->ref_ctr_offset == 0) 298 snprintf(buf, sizeof(buf), "0x%0*lx", 299 (int)(sizeof(void *) * 2), tu->offset); 300 else 301 snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)", 302 (int)(sizeof(void *) * 2), tu->offset, 303 tu->ref_ctr_offset); 304 if (strcmp(buf, &argv[0][len + 1])) 305 return false; 306 307 argc--; argv++; 308 309 return trace_probe_match_command_args(&tu->tp, argc, argv); 310 } 311 312 static bool trace_uprobe_match(const char *system, const char *event, 313 int argc, const char **argv, struct dyn_event *ev) 314 { 315 struct trace_uprobe *tu = to_trace_uprobe(ev); 316 317 return strcmp(trace_probe_name(&tu->tp), event) == 0 && 318 (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) && 319 trace_uprobe_match_command_head(tu, argc, argv); 320 } 321 322 static nokprobe_inline struct trace_uprobe * 323 trace_uprobe_primary_from_call(struct trace_event_call *call) 324 { 325 struct trace_probe *tp; 326 327 tp = trace_probe_primary_from_call(call); 328 if (WARN_ON_ONCE(!tp)) 329 return NULL; 330 331 return container_of(tp, struct trace_uprobe, tp); 332 } 333 334 /* 335 * Allocate new trace_uprobe and initialize it (including uprobes). 336 */ 337 static struct trace_uprobe * 338 alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret) 339 { 340 struct trace_uprobe *tu; 341 int ret; 342 343 tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL); 344 if (!tu) 345 return ERR_PTR(-ENOMEM); 346 347 ret = trace_probe_init(&tu->tp, event, group, true); 348 if (ret < 0) 349 goto error; 350 351 dyn_event_init(&tu->devent, &trace_uprobe_ops); 352 tu->consumer.handler = uprobe_dispatcher; 353 if (is_ret) 354 tu->consumer.ret_handler = uretprobe_dispatcher; 355 init_trace_uprobe_filter(tu->tp.event->filter); 356 return tu; 357 358 error: 359 kfree(tu); 360 361 return ERR_PTR(ret); 362 } 363 364 static void free_trace_uprobe(struct trace_uprobe *tu) 365 { 366 if (!tu) 367 return; 368 369 path_put(&tu->path); 370 trace_probe_cleanup(&tu->tp); 371 kfree(tu->filename); 372 kfree(tu); 373 } 374 375 static struct trace_uprobe *find_probe_event(const char *event, const char *group) 376 { 377 struct dyn_event *pos; 378 struct trace_uprobe *tu; 379 380 for_each_trace_uprobe(tu, pos) 381 if (strcmp(trace_probe_name(&tu->tp), event) == 0 && 382 strcmp(trace_probe_group_name(&tu->tp), group) == 0) 383 return tu; 384 385 return NULL; 386 } 387 388 /* Unregister a trace_uprobe and probe_event */ 389 static int unregister_trace_uprobe(struct trace_uprobe *tu) 390 { 391 int ret; 392 393 if (trace_probe_has_sibling(&tu->tp)) 394 goto unreg; 395 396 ret = unregister_uprobe_event(tu); 397 if (ret) 398 return ret; 399 400 unreg: 401 dyn_event_remove(&tu->devent); 402 trace_probe_unlink(&tu->tp); 403 free_trace_uprobe(tu); 404 return 0; 405 } 406 407 static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig, 408 struct trace_uprobe *comp) 409 { 410 struct trace_probe_event *tpe = orig->tp.event; 411 struct trace_probe *pos; 412 struct inode *comp_inode = d_real_inode(comp->path.dentry); 413 int i; 414 415 list_for_each_entry(pos, &tpe->probes, list) { 416 orig = container_of(pos, struct trace_uprobe, tp); 417 if (comp_inode != d_real_inode(orig->path.dentry) || 418 comp->offset != orig->offset) 419 continue; 420 421 /* 422 * trace_probe_compare_arg_type() ensured that nr_args and 423 * each argument name and type are same. Let's compare comm. 424 */ 425 for (i = 0; i < orig->tp.nr_args; i++) { 426 if (strcmp(orig->tp.args[i].comm, 427 comp->tp.args[i].comm)) 428 break; 429 } 430 431 if (i == orig->tp.nr_args) 432 return true; 433 } 434 435 return false; 436 } 437 438 static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to) 439 { 440 int ret; 441 442 ret = trace_probe_compare_arg_type(&tu->tp, &to->tp); 443 if (ret) { 444 /* Note that argument starts index = 2 */ 445 trace_probe_log_set_index(ret + 1); 446 trace_probe_log_err(0, DIFF_ARG_TYPE); 447 return -EEXIST; 448 } 449 if (trace_uprobe_has_same_uprobe(to, tu)) { 450 trace_probe_log_set_index(0); 451 trace_probe_log_err(0, SAME_PROBE); 452 return -EEXIST; 453 } 454 455 /* Append to existing event */ 456 ret = trace_probe_append(&tu->tp, &to->tp); 457 if (!ret) 458 dyn_event_add(&tu->devent); 459 460 return ret; 461 } 462 463 /* 464 * Uprobe with multiple reference counter is not allowed. i.e. 465 * If inode and offset matches, reference counter offset *must* 466 * match as well. Though, there is one exception: If user is 467 * replacing old trace_uprobe with new one(same group/event), 468 * then we allow same uprobe with new reference counter as far 469 * as the new one does not conflict with any other existing 470 * ones. 471 */ 472 static int validate_ref_ctr_offset(struct trace_uprobe *new) 473 { 474 struct dyn_event *pos; 475 struct trace_uprobe *tmp; 476 struct inode *new_inode = d_real_inode(new->path.dentry); 477 478 for_each_trace_uprobe(tmp, pos) { 479 if (new_inode == d_real_inode(tmp->path.dentry) && 480 new->offset == tmp->offset && 481 new->ref_ctr_offset != tmp->ref_ctr_offset) { 482 pr_warn("Reference counter offset mismatch."); 483 return -EINVAL; 484 } 485 } 486 return 0; 487 } 488 489 /* Register a trace_uprobe and probe_event */ 490 static int register_trace_uprobe(struct trace_uprobe *tu) 491 { 492 struct trace_uprobe *old_tu; 493 int ret; 494 495 mutex_lock(&event_mutex); 496 497 ret = validate_ref_ctr_offset(tu); 498 if (ret) 499 goto end; 500 501 /* register as an event */ 502 old_tu = find_probe_event(trace_probe_name(&tu->tp), 503 trace_probe_group_name(&tu->tp)); 504 if (old_tu) { 505 if (is_ret_probe(tu) != is_ret_probe(old_tu)) { 506 trace_probe_log_set_index(0); 507 trace_probe_log_err(0, DIFF_PROBE_TYPE); 508 ret = -EEXIST; 509 } else { 510 ret = append_trace_uprobe(tu, old_tu); 511 } 512 goto end; 513 } 514 515 ret = register_uprobe_event(tu); 516 if (ret) { 517 pr_warn("Failed to register probe event(%d)\n", ret); 518 goto end; 519 } 520 521 dyn_event_add(&tu->devent); 522 523 end: 524 mutex_unlock(&event_mutex); 525 526 return ret; 527 } 528 529 /* 530 * Argument syntax: 531 * - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET[%return][(REF)] [FETCHARGS] 532 */ 533 static int __trace_uprobe_create(int argc, const char **argv) 534 { 535 struct trace_uprobe *tu; 536 const char *event = NULL, *group = UPROBE_EVENT_SYSTEM; 537 char *arg, *filename, *rctr, *rctr_end, *tmp; 538 char buf[MAX_EVENT_NAME_LEN]; 539 struct path path; 540 unsigned long offset, ref_ctr_offset; 541 bool is_return = false; 542 int i, ret; 543 544 ret = 0; 545 ref_ctr_offset = 0; 546 547 switch (argv[0][0]) { 548 case 'r': 549 is_return = true; 550 break; 551 case 'p': 552 break; 553 default: 554 return -ECANCELED; 555 } 556 557 if (argc < 2) 558 return -ECANCELED; 559 560 if (argv[0][1] == ':') 561 event = &argv[0][2]; 562 563 if (!strchr(argv[1], '/')) 564 return -ECANCELED; 565 566 filename = kstrdup(argv[1], GFP_KERNEL); 567 if (!filename) 568 return -ENOMEM; 569 570 /* Find the last occurrence, in case the path contains ':' too. */ 571 arg = strrchr(filename, ':'); 572 if (!arg || !isdigit(arg[1])) { 573 kfree(filename); 574 return -ECANCELED; 575 } 576 577 trace_probe_log_init("trace_uprobe", argc, argv); 578 trace_probe_log_set_index(1); /* filename is the 2nd argument */ 579 580 *arg++ = '\0'; 581 ret = kern_path(filename, LOOKUP_FOLLOW, &path); 582 if (ret) { 583 trace_probe_log_err(0, FILE_NOT_FOUND); 584 kfree(filename); 585 trace_probe_log_clear(); 586 return ret; 587 } 588 if (!d_is_reg(path.dentry)) { 589 trace_probe_log_err(0, NO_REGULAR_FILE); 590 ret = -EINVAL; 591 goto fail_address_parse; 592 } 593 594 /* Parse reference counter offset if specified. */ 595 rctr = strchr(arg, '('); 596 if (rctr) { 597 rctr_end = strchr(rctr, ')'); 598 if (!rctr_end) { 599 ret = -EINVAL; 600 rctr_end = rctr + strlen(rctr); 601 trace_probe_log_err(rctr_end - filename, 602 REFCNT_OPEN_BRACE); 603 goto fail_address_parse; 604 } else if (rctr_end[1] != '\0') { 605 ret = -EINVAL; 606 trace_probe_log_err(rctr_end + 1 - filename, 607 BAD_REFCNT_SUFFIX); 608 goto fail_address_parse; 609 } 610 611 *rctr++ = '\0'; 612 *rctr_end = '\0'; 613 ret = kstrtoul(rctr, 0, &ref_ctr_offset); 614 if (ret) { 615 trace_probe_log_err(rctr - filename, BAD_REFCNT); 616 goto fail_address_parse; 617 } 618 } 619 620 /* Check if there is %return suffix */ 621 tmp = strchr(arg, '%'); 622 if (tmp) { 623 if (!strcmp(tmp, "%return")) { 624 *tmp = '\0'; 625 is_return = true; 626 } else { 627 trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX); 628 ret = -EINVAL; 629 goto fail_address_parse; 630 } 631 } 632 633 /* Parse uprobe offset. */ 634 ret = kstrtoul(arg, 0, &offset); 635 if (ret) { 636 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS); 637 goto fail_address_parse; 638 } 639 640 /* setup a probe */ 641 trace_probe_log_set_index(0); 642 if (event) { 643 ret = traceprobe_parse_event_name(&event, &group, buf, 644 event - argv[0]); 645 if (ret) 646 goto fail_address_parse; 647 } else { 648 char *tail; 649 char *ptr; 650 651 tail = kstrdup(kbasename(filename), GFP_KERNEL); 652 if (!tail) { 653 ret = -ENOMEM; 654 goto fail_address_parse; 655 } 656 657 ptr = strpbrk(tail, ".-_"); 658 if (ptr) 659 *ptr = '\0'; 660 661 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset); 662 event = buf; 663 kfree(tail); 664 } 665 666 argc -= 2; 667 argv += 2; 668 669 tu = alloc_trace_uprobe(group, event, argc, is_return); 670 if (IS_ERR(tu)) { 671 ret = PTR_ERR(tu); 672 /* This must return -ENOMEM otherwise there is a bug */ 673 WARN_ON_ONCE(ret != -ENOMEM); 674 goto fail_address_parse; 675 } 676 tu->offset = offset; 677 tu->ref_ctr_offset = ref_ctr_offset; 678 tu->path = path; 679 tu->filename = filename; 680 681 /* parse arguments */ 682 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { 683 tmp = kstrdup(argv[i], GFP_KERNEL); 684 if (!tmp) { 685 ret = -ENOMEM; 686 goto error; 687 } 688 689 trace_probe_log_set_index(i + 2); 690 ret = traceprobe_parse_probe_arg(&tu->tp, i, tmp, 691 is_return ? TPARG_FL_RETURN : 0); 692 kfree(tmp); 693 if (ret) 694 goto error; 695 } 696 697 ret = traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)); 698 if (ret < 0) 699 goto error; 700 701 ret = register_trace_uprobe(tu); 702 if (!ret) 703 goto out; 704 705 error: 706 free_trace_uprobe(tu); 707 out: 708 trace_probe_log_clear(); 709 return ret; 710 711 fail_address_parse: 712 trace_probe_log_clear(); 713 path_put(&path); 714 kfree(filename); 715 716 return ret; 717 } 718 719 int trace_uprobe_create(const char *raw_command) 720 { 721 return trace_probe_create(raw_command, __trace_uprobe_create); 722 } 723 724 static int create_or_delete_trace_uprobe(const char *raw_command) 725 { 726 int ret; 727 728 if (raw_command[0] == '-') 729 return dyn_event_release(raw_command, &trace_uprobe_ops); 730 731 ret = trace_uprobe_create(raw_command); 732 return ret == -ECANCELED ? -EINVAL : ret; 733 } 734 735 static int trace_uprobe_release(struct dyn_event *ev) 736 { 737 struct trace_uprobe *tu = to_trace_uprobe(ev); 738 739 return unregister_trace_uprobe(tu); 740 } 741 742 /* Probes listing interfaces */ 743 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev) 744 { 745 struct trace_uprobe *tu = to_trace_uprobe(ev); 746 char c = is_ret_probe(tu) ? 'r' : 'p'; 747 int i; 748 749 seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp), 750 trace_probe_name(&tu->tp), tu->filename, 751 (int)(sizeof(void *) * 2), tu->offset); 752 753 if (tu->ref_ctr_offset) 754 seq_printf(m, "(0x%lx)", tu->ref_ctr_offset); 755 756 for (i = 0; i < tu->tp.nr_args; i++) 757 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm); 758 759 seq_putc(m, '\n'); 760 return 0; 761 } 762 763 static int probes_seq_show(struct seq_file *m, void *v) 764 { 765 struct dyn_event *ev = v; 766 767 if (!is_trace_uprobe(ev)) 768 return 0; 769 770 return trace_uprobe_show(m, ev); 771 } 772 773 static const struct seq_operations probes_seq_op = { 774 .start = dyn_event_seq_start, 775 .next = dyn_event_seq_next, 776 .stop = dyn_event_seq_stop, 777 .show = probes_seq_show 778 }; 779 780 static int probes_open(struct inode *inode, struct file *file) 781 { 782 int ret; 783 784 ret = security_locked_down(LOCKDOWN_TRACEFS); 785 if (ret) 786 return ret; 787 788 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { 789 ret = dyn_events_release_all(&trace_uprobe_ops); 790 if (ret) 791 return ret; 792 } 793 794 return seq_open(file, &probes_seq_op); 795 } 796 797 static ssize_t probes_write(struct file *file, const char __user *buffer, 798 size_t count, loff_t *ppos) 799 { 800 return trace_parse_run_command(file, buffer, count, ppos, 801 create_or_delete_trace_uprobe); 802 } 803 804 static const struct file_operations uprobe_events_ops = { 805 .owner = THIS_MODULE, 806 .open = probes_open, 807 .read = seq_read, 808 .llseek = seq_lseek, 809 .release = seq_release, 810 .write = probes_write, 811 }; 812 813 /* Probes profiling interfaces */ 814 static int probes_profile_seq_show(struct seq_file *m, void *v) 815 { 816 struct dyn_event *ev = v; 817 struct trace_uprobe *tu; 818 819 if (!is_trace_uprobe(ev)) 820 return 0; 821 822 tu = to_trace_uprobe(ev); 823 seq_printf(m, " %s %-44s %15lu\n", tu->filename, 824 trace_probe_name(&tu->tp), tu->nhit); 825 return 0; 826 } 827 828 static const struct seq_operations profile_seq_op = { 829 .start = dyn_event_seq_start, 830 .next = dyn_event_seq_next, 831 .stop = dyn_event_seq_stop, 832 .show = probes_profile_seq_show 833 }; 834 835 static int profile_open(struct inode *inode, struct file *file) 836 { 837 int ret; 838 839 ret = security_locked_down(LOCKDOWN_TRACEFS); 840 if (ret) 841 return ret; 842 843 return seq_open(file, &profile_seq_op); 844 } 845 846 static const struct file_operations uprobe_profile_ops = { 847 .owner = THIS_MODULE, 848 .open = profile_open, 849 .read = seq_read, 850 .llseek = seq_lseek, 851 .release = seq_release, 852 }; 853 854 struct uprobe_cpu_buffer { 855 struct mutex mutex; 856 void *buf; 857 }; 858 static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer; 859 static int uprobe_buffer_refcnt; 860 861 static int uprobe_buffer_init(void) 862 { 863 int cpu, err_cpu; 864 865 uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer); 866 if (uprobe_cpu_buffer == NULL) 867 return -ENOMEM; 868 869 for_each_possible_cpu(cpu) { 870 struct page *p = alloc_pages_node(cpu_to_node(cpu), 871 GFP_KERNEL, 0); 872 if (p == NULL) { 873 err_cpu = cpu; 874 goto err; 875 } 876 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p); 877 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex); 878 } 879 880 return 0; 881 882 err: 883 for_each_possible_cpu(cpu) { 884 if (cpu == err_cpu) 885 break; 886 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf); 887 } 888 889 free_percpu(uprobe_cpu_buffer); 890 return -ENOMEM; 891 } 892 893 static int uprobe_buffer_enable(void) 894 { 895 int ret = 0; 896 897 BUG_ON(!mutex_is_locked(&event_mutex)); 898 899 if (uprobe_buffer_refcnt++ == 0) { 900 ret = uprobe_buffer_init(); 901 if (ret < 0) 902 uprobe_buffer_refcnt--; 903 } 904 905 return ret; 906 } 907 908 static void uprobe_buffer_disable(void) 909 { 910 int cpu; 911 912 BUG_ON(!mutex_is_locked(&event_mutex)); 913 914 if (--uprobe_buffer_refcnt == 0) { 915 for_each_possible_cpu(cpu) 916 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, 917 cpu)->buf); 918 919 free_percpu(uprobe_cpu_buffer); 920 uprobe_cpu_buffer = NULL; 921 } 922 } 923 924 static struct uprobe_cpu_buffer *uprobe_buffer_get(void) 925 { 926 struct uprobe_cpu_buffer *ucb; 927 int cpu; 928 929 cpu = raw_smp_processor_id(); 930 ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu); 931 932 /* 933 * Use per-cpu buffers for fastest access, but we might migrate 934 * so the mutex makes sure we have sole access to it. 935 */ 936 mutex_lock(&ucb->mutex); 937 938 return ucb; 939 } 940 941 static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb) 942 { 943 mutex_unlock(&ucb->mutex); 944 } 945 946 static void __uprobe_trace_func(struct trace_uprobe *tu, 947 unsigned long func, struct pt_regs *regs, 948 struct uprobe_cpu_buffer *ucb, int dsize, 949 struct trace_event_file *trace_file) 950 { 951 struct uprobe_trace_entry_head *entry; 952 struct trace_buffer *buffer; 953 struct ring_buffer_event *event; 954 void *data; 955 int size, esize; 956 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 957 958 WARN_ON(call != trace_file->event_call); 959 960 if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE)) 961 return; 962 963 if (trace_trigger_soft_disabled(trace_file)) 964 return; 965 966 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 967 size = esize + tu->tp.size + dsize; 968 event = trace_event_buffer_lock_reserve(&buffer, trace_file, 969 call->event.type, size, 0); 970 if (!event) 971 return; 972 973 entry = ring_buffer_event_data(event); 974 if (is_ret_probe(tu)) { 975 entry->vaddr[0] = func; 976 entry->vaddr[1] = instruction_pointer(regs); 977 data = DATAOF_TRACE_ENTRY(entry, true); 978 } else { 979 entry->vaddr[0] = instruction_pointer(regs); 980 data = DATAOF_TRACE_ENTRY(entry, false); 981 } 982 983 memcpy(data, ucb->buf, tu->tp.size + dsize); 984 985 event_trigger_unlock_commit(trace_file, buffer, event, entry, 0); 986 } 987 988 /* uprobe handler */ 989 static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs, 990 struct uprobe_cpu_buffer *ucb, int dsize) 991 { 992 struct event_file_link *link; 993 994 if (is_ret_probe(tu)) 995 return 0; 996 997 rcu_read_lock(); 998 trace_probe_for_each_link_rcu(link, &tu->tp) 999 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file); 1000 rcu_read_unlock(); 1001 1002 return 0; 1003 } 1004 1005 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func, 1006 struct pt_regs *regs, 1007 struct uprobe_cpu_buffer *ucb, int dsize) 1008 { 1009 struct event_file_link *link; 1010 1011 rcu_read_lock(); 1012 trace_probe_for_each_link_rcu(link, &tu->tp) 1013 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file); 1014 rcu_read_unlock(); 1015 } 1016 1017 /* Event entry printers */ 1018 static enum print_line_t 1019 print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) 1020 { 1021 struct uprobe_trace_entry_head *entry; 1022 struct trace_seq *s = &iter->seq; 1023 struct trace_uprobe *tu; 1024 u8 *data; 1025 1026 entry = (struct uprobe_trace_entry_head *)iter->ent; 1027 tu = trace_uprobe_primary_from_call( 1028 container_of(event, struct trace_event_call, event)); 1029 if (unlikely(!tu)) 1030 goto out; 1031 1032 if (is_ret_probe(tu)) { 1033 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)", 1034 trace_probe_name(&tu->tp), 1035 entry->vaddr[1], entry->vaddr[0]); 1036 data = DATAOF_TRACE_ENTRY(entry, true); 1037 } else { 1038 trace_seq_printf(s, "%s: (0x%lx)", 1039 trace_probe_name(&tu->tp), 1040 entry->vaddr[0]); 1041 data = DATAOF_TRACE_ENTRY(entry, false); 1042 } 1043 1044 if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0) 1045 goto out; 1046 1047 trace_seq_putc(s, '\n'); 1048 1049 out: 1050 return trace_handle_return(s); 1051 } 1052 1053 typedef bool (*filter_func_t)(struct uprobe_consumer *self, 1054 enum uprobe_filter_ctx ctx, 1055 struct mm_struct *mm); 1056 1057 static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter) 1058 { 1059 int ret; 1060 1061 tu->consumer.filter = filter; 1062 tu->inode = d_real_inode(tu->path.dentry); 1063 1064 if (tu->ref_ctr_offset) 1065 ret = uprobe_register_refctr(tu->inode, tu->offset, 1066 tu->ref_ctr_offset, &tu->consumer); 1067 else 1068 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer); 1069 1070 if (ret) 1071 tu->inode = NULL; 1072 1073 return ret; 1074 } 1075 1076 static void __probe_event_disable(struct trace_probe *tp) 1077 { 1078 struct trace_probe *pos; 1079 struct trace_uprobe *tu; 1080 1081 tu = container_of(tp, struct trace_uprobe, tp); 1082 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter)); 1083 1084 list_for_each_entry(pos, trace_probe_probe_list(tp), list) { 1085 tu = container_of(pos, struct trace_uprobe, tp); 1086 if (!tu->inode) 1087 continue; 1088 1089 uprobe_unregister(tu->inode, tu->offset, &tu->consumer); 1090 tu->inode = NULL; 1091 } 1092 } 1093 1094 static int probe_event_enable(struct trace_event_call *call, 1095 struct trace_event_file *file, filter_func_t filter) 1096 { 1097 struct trace_probe *pos, *tp; 1098 struct trace_uprobe *tu; 1099 bool enabled; 1100 int ret; 1101 1102 tp = trace_probe_primary_from_call(call); 1103 if (WARN_ON_ONCE(!tp)) 1104 return -ENODEV; 1105 enabled = trace_probe_is_enabled(tp); 1106 1107 /* This may also change "enabled" state */ 1108 if (file) { 1109 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE)) 1110 return -EINTR; 1111 1112 ret = trace_probe_add_file(tp, file); 1113 if (ret < 0) 1114 return ret; 1115 } else { 1116 if (trace_probe_test_flag(tp, TP_FLAG_TRACE)) 1117 return -EINTR; 1118 1119 trace_probe_set_flag(tp, TP_FLAG_PROFILE); 1120 } 1121 1122 tu = container_of(tp, struct trace_uprobe, tp); 1123 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter)); 1124 1125 if (enabled) 1126 return 0; 1127 1128 ret = uprobe_buffer_enable(); 1129 if (ret) 1130 goto err_flags; 1131 1132 list_for_each_entry(pos, trace_probe_probe_list(tp), list) { 1133 tu = container_of(pos, struct trace_uprobe, tp); 1134 ret = trace_uprobe_enable(tu, filter); 1135 if (ret) { 1136 __probe_event_disable(tp); 1137 goto err_buffer; 1138 } 1139 } 1140 1141 return 0; 1142 1143 err_buffer: 1144 uprobe_buffer_disable(); 1145 1146 err_flags: 1147 if (file) 1148 trace_probe_remove_file(tp, file); 1149 else 1150 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 1151 1152 return ret; 1153 } 1154 1155 static void probe_event_disable(struct trace_event_call *call, 1156 struct trace_event_file *file) 1157 { 1158 struct trace_probe *tp; 1159 1160 tp = trace_probe_primary_from_call(call); 1161 if (WARN_ON_ONCE(!tp)) 1162 return; 1163 1164 if (!trace_probe_is_enabled(tp)) 1165 return; 1166 1167 if (file) { 1168 if (trace_probe_remove_file(tp, file) < 0) 1169 return; 1170 1171 if (trace_probe_is_enabled(tp)) 1172 return; 1173 } else 1174 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 1175 1176 __probe_event_disable(tp); 1177 uprobe_buffer_disable(); 1178 } 1179 1180 static int uprobe_event_define_fields(struct trace_event_call *event_call) 1181 { 1182 int ret, size; 1183 struct uprobe_trace_entry_head field; 1184 struct trace_uprobe *tu; 1185 1186 tu = trace_uprobe_primary_from_call(event_call); 1187 if (unlikely(!tu)) 1188 return -ENODEV; 1189 1190 if (is_ret_probe(tu)) { 1191 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0); 1192 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0); 1193 size = SIZEOF_TRACE_ENTRY(true); 1194 } else { 1195 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0); 1196 size = SIZEOF_TRACE_ENTRY(false); 1197 } 1198 1199 return traceprobe_define_arg_fields(event_call, size, &tu->tp); 1200 } 1201 1202 #ifdef CONFIG_PERF_EVENTS 1203 static bool 1204 __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm) 1205 { 1206 struct perf_event *event; 1207 1208 if (filter->nr_systemwide) 1209 return true; 1210 1211 list_for_each_entry(event, &filter->perf_events, hw.tp_list) { 1212 if (event->hw.target->mm == mm) 1213 return true; 1214 } 1215 1216 return false; 1217 } 1218 1219 static inline bool 1220 trace_uprobe_filter_event(struct trace_uprobe_filter *filter, 1221 struct perf_event *event) 1222 { 1223 return __uprobe_perf_filter(filter, event->hw.target->mm); 1224 } 1225 1226 static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter, 1227 struct perf_event *event) 1228 { 1229 bool done; 1230 1231 write_lock(&filter->rwlock); 1232 if (event->hw.target) { 1233 list_del(&event->hw.tp_list); 1234 done = filter->nr_systemwide || 1235 (event->hw.target->flags & PF_EXITING) || 1236 trace_uprobe_filter_event(filter, event); 1237 } else { 1238 filter->nr_systemwide--; 1239 done = filter->nr_systemwide; 1240 } 1241 write_unlock(&filter->rwlock); 1242 1243 return done; 1244 } 1245 1246 /* This returns true if the filter always covers target mm */ 1247 static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter, 1248 struct perf_event *event) 1249 { 1250 bool done; 1251 1252 write_lock(&filter->rwlock); 1253 if (event->hw.target) { 1254 /* 1255 * event->parent != NULL means copy_process(), we can avoid 1256 * uprobe_apply(). current->mm must be probed and we can rely 1257 * on dup_mmap() which preserves the already installed bp's. 1258 * 1259 * attr.enable_on_exec means that exec/mmap will install the 1260 * breakpoints we need. 1261 */ 1262 done = filter->nr_systemwide || 1263 event->parent || event->attr.enable_on_exec || 1264 trace_uprobe_filter_event(filter, event); 1265 list_add(&event->hw.tp_list, &filter->perf_events); 1266 } else { 1267 done = filter->nr_systemwide; 1268 filter->nr_systemwide++; 1269 } 1270 write_unlock(&filter->rwlock); 1271 1272 return done; 1273 } 1274 1275 static int uprobe_perf_close(struct trace_event_call *call, 1276 struct perf_event *event) 1277 { 1278 struct trace_probe *pos, *tp; 1279 struct trace_uprobe *tu; 1280 int ret = 0; 1281 1282 tp = trace_probe_primary_from_call(call); 1283 if (WARN_ON_ONCE(!tp)) 1284 return -ENODEV; 1285 1286 tu = container_of(tp, struct trace_uprobe, tp); 1287 if (trace_uprobe_filter_remove(tu->tp.event->filter, event)) 1288 return 0; 1289 1290 list_for_each_entry(pos, trace_probe_probe_list(tp), list) { 1291 tu = container_of(pos, struct trace_uprobe, tp); 1292 ret = uprobe_apply(tu->inode, tu->offset, &tu->consumer, false); 1293 if (ret) 1294 break; 1295 } 1296 1297 return ret; 1298 } 1299 1300 static int uprobe_perf_open(struct trace_event_call *call, 1301 struct perf_event *event) 1302 { 1303 struct trace_probe *pos, *tp; 1304 struct trace_uprobe *tu; 1305 int err = 0; 1306 1307 tp = trace_probe_primary_from_call(call); 1308 if (WARN_ON_ONCE(!tp)) 1309 return -ENODEV; 1310 1311 tu = container_of(tp, struct trace_uprobe, tp); 1312 if (trace_uprobe_filter_add(tu->tp.event->filter, event)) 1313 return 0; 1314 1315 list_for_each_entry(pos, trace_probe_probe_list(tp), list) { 1316 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true); 1317 if (err) { 1318 uprobe_perf_close(call, event); 1319 break; 1320 } 1321 } 1322 1323 return err; 1324 } 1325 1326 static bool uprobe_perf_filter(struct uprobe_consumer *uc, 1327 enum uprobe_filter_ctx ctx, struct mm_struct *mm) 1328 { 1329 struct trace_uprobe_filter *filter; 1330 struct trace_uprobe *tu; 1331 int ret; 1332 1333 tu = container_of(uc, struct trace_uprobe, consumer); 1334 filter = tu->tp.event->filter; 1335 1336 read_lock(&filter->rwlock); 1337 ret = __uprobe_perf_filter(filter, mm); 1338 read_unlock(&filter->rwlock); 1339 1340 return ret; 1341 } 1342 1343 static void __uprobe_perf_func(struct trace_uprobe *tu, 1344 unsigned long func, struct pt_regs *regs, 1345 struct uprobe_cpu_buffer *ucb, int dsize) 1346 { 1347 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 1348 struct uprobe_trace_entry_head *entry; 1349 struct hlist_head *head; 1350 void *data; 1351 int size, esize; 1352 int rctx; 1353 1354 if (bpf_prog_array_valid(call)) { 1355 u32 ret; 1356 1357 preempt_disable(); 1358 ret = trace_call_bpf(call, regs); 1359 preempt_enable(); 1360 if (!ret) 1361 return; 1362 } 1363 1364 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1365 1366 size = esize + tu->tp.size + dsize; 1367 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32); 1368 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) 1369 return; 1370 1371 preempt_disable(); 1372 head = this_cpu_ptr(call->perf_events); 1373 if (hlist_empty(head)) 1374 goto out; 1375 1376 entry = perf_trace_buf_alloc(size, NULL, &rctx); 1377 if (!entry) 1378 goto out; 1379 1380 if (is_ret_probe(tu)) { 1381 entry->vaddr[0] = func; 1382 entry->vaddr[1] = instruction_pointer(regs); 1383 data = DATAOF_TRACE_ENTRY(entry, true); 1384 } else { 1385 entry->vaddr[0] = instruction_pointer(regs); 1386 data = DATAOF_TRACE_ENTRY(entry, false); 1387 } 1388 1389 memcpy(data, ucb->buf, tu->tp.size + dsize); 1390 1391 if (size - esize > tu->tp.size + dsize) { 1392 int len = tu->tp.size + dsize; 1393 1394 memset(data + len, 0, size - esize - len); 1395 } 1396 1397 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, 1398 head, NULL); 1399 out: 1400 preempt_enable(); 1401 } 1402 1403 /* uprobe profile handler */ 1404 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs, 1405 struct uprobe_cpu_buffer *ucb, int dsize) 1406 { 1407 if (!uprobe_perf_filter(&tu->consumer, 0, current->mm)) 1408 return UPROBE_HANDLER_REMOVE; 1409 1410 if (!is_ret_probe(tu)) 1411 __uprobe_perf_func(tu, 0, regs, ucb, dsize); 1412 return 0; 1413 } 1414 1415 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func, 1416 struct pt_regs *regs, 1417 struct uprobe_cpu_buffer *ucb, int dsize) 1418 { 1419 __uprobe_perf_func(tu, func, regs, ucb, dsize); 1420 } 1421 1422 int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type, 1423 const char **filename, u64 *probe_offset, 1424 bool perf_type_tracepoint) 1425 { 1426 const char *pevent = trace_event_name(event->tp_event); 1427 const char *group = event->tp_event->class->system; 1428 struct trace_uprobe *tu; 1429 1430 if (perf_type_tracepoint) 1431 tu = find_probe_event(pevent, group); 1432 else 1433 tu = trace_uprobe_primary_from_call(event->tp_event); 1434 if (!tu) 1435 return -EINVAL; 1436 1437 *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE 1438 : BPF_FD_TYPE_UPROBE; 1439 *filename = tu->filename; 1440 *probe_offset = tu->offset; 1441 return 0; 1442 } 1443 #endif /* CONFIG_PERF_EVENTS */ 1444 1445 static int 1446 trace_uprobe_register(struct trace_event_call *event, enum trace_reg type, 1447 void *data) 1448 { 1449 struct trace_event_file *file = data; 1450 1451 switch (type) { 1452 case TRACE_REG_REGISTER: 1453 return probe_event_enable(event, file, NULL); 1454 1455 case TRACE_REG_UNREGISTER: 1456 probe_event_disable(event, file); 1457 return 0; 1458 1459 #ifdef CONFIG_PERF_EVENTS 1460 case TRACE_REG_PERF_REGISTER: 1461 return probe_event_enable(event, NULL, uprobe_perf_filter); 1462 1463 case TRACE_REG_PERF_UNREGISTER: 1464 probe_event_disable(event, NULL); 1465 return 0; 1466 1467 case TRACE_REG_PERF_OPEN: 1468 return uprobe_perf_open(event, data); 1469 1470 case TRACE_REG_PERF_CLOSE: 1471 return uprobe_perf_close(event, data); 1472 1473 #endif 1474 default: 1475 return 0; 1476 } 1477 } 1478 1479 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) 1480 { 1481 struct trace_uprobe *tu; 1482 struct uprobe_dispatch_data udd; 1483 struct uprobe_cpu_buffer *ucb; 1484 int dsize, esize; 1485 int ret = 0; 1486 1487 1488 tu = container_of(con, struct trace_uprobe, consumer); 1489 tu->nhit++; 1490 1491 udd.tu = tu; 1492 udd.bp_addr = instruction_pointer(regs); 1493 1494 current->utask->vaddr = (unsigned long) &udd; 1495 1496 if (WARN_ON_ONCE(!uprobe_cpu_buffer)) 1497 return 0; 1498 1499 dsize = __get_data_size(&tu->tp, regs); 1500 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1501 1502 ucb = uprobe_buffer_get(); 1503 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize); 1504 1505 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) 1506 ret |= uprobe_trace_func(tu, regs, ucb, dsize); 1507 1508 #ifdef CONFIG_PERF_EVENTS 1509 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) 1510 ret |= uprobe_perf_func(tu, regs, ucb, dsize); 1511 #endif 1512 uprobe_buffer_put(ucb); 1513 return ret; 1514 } 1515 1516 static int uretprobe_dispatcher(struct uprobe_consumer *con, 1517 unsigned long func, struct pt_regs *regs) 1518 { 1519 struct trace_uprobe *tu; 1520 struct uprobe_dispatch_data udd; 1521 struct uprobe_cpu_buffer *ucb; 1522 int dsize, esize; 1523 1524 tu = container_of(con, struct trace_uprobe, consumer); 1525 1526 udd.tu = tu; 1527 udd.bp_addr = func; 1528 1529 current->utask->vaddr = (unsigned long) &udd; 1530 1531 if (WARN_ON_ONCE(!uprobe_cpu_buffer)) 1532 return 0; 1533 1534 dsize = __get_data_size(&tu->tp, regs); 1535 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1536 1537 ucb = uprobe_buffer_get(); 1538 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize); 1539 1540 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) 1541 uretprobe_trace_func(tu, func, regs, ucb, dsize); 1542 1543 #ifdef CONFIG_PERF_EVENTS 1544 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) 1545 uretprobe_perf_func(tu, func, regs, ucb, dsize); 1546 #endif 1547 uprobe_buffer_put(ucb); 1548 return 0; 1549 } 1550 1551 static struct trace_event_functions uprobe_funcs = { 1552 .trace = print_uprobe_event 1553 }; 1554 1555 static struct trace_event_fields uprobe_fields_array[] = { 1556 { .type = TRACE_FUNCTION_TYPE, 1557 .define_fields = uprobe_event_define_fields }, 1558 {} 1559 }; 1560 1561 static inline void init_trace_event_call(struct trace_uprobe *tu) 1562 { 1563 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 1564 call->event.funcs = &uprobe_funcs; 1565 call->class->fields_array = uprobe_fields_array; 1566 1567 call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY; 1568 call->class->reg = trace_uprobe_register; 1569 } 1570 1571 static int register_uprobe_event(struct trace_uprobe *tu) 1572 { 1573 init_trace_event_call(tu); 1574 1575 return trace_probe_register_event_call(&tu->tp); 1576 } 1577 1578 static int unregister_uprobe_event(struct trace_uprobe *tu) 1579 { 1580 return trace_probe_unregister_event_call(&tu->tp); 1581 } 1582 1583 #ifdef CONFIG_PERF_EVENTS 1584 struct trace_event_call * 1585 create_local_trace_uprobe(char *name, unsigned long offs, 1586 unsigned long ref_ctr_offset, bool is_return) 1587 { 1588 struct trace_uprobe *tu; 1589 struct path path; 1590 int ret; 1591 1592 ret = kern_path(name, LOOKUP_FOLLOW, &path); 1593 if (ret) 1594 return ERR_PTR(ret); 1595 1596 if (!d_is_reg(path.dentry)) { 1597 path_put(&path); 1598 return ERR_PTR(-EINVAL); 1599 } 1600 1601 /* 1602 * local trace_kprobes are not added to dyn_event, so they are never 1603 * searched in find_trace_kprobe(). Therefore, there is no concern of 1604 * duplicated name "DUMMY_EVENT" here. 1605 */ 1606 tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0, 1607 is_return); 1608 1609 if (IS_ERR(tu)) { 1610 pr_info("Failed to allocate trace_uprobe.(%d)\n", 1611 (int)PTR_ERR(tu)); 1612 path_put(&path); 1613 return ERR_CAST(tu); 1614 } 1615 1616 tu->offset = offs; 1617 tu->path = path; 1618 tu->ref_ctr_offset = ref_ctr_offset; 1619 tu->filename = kstrdup(name, GFP_KERNEL); 1620 init_trace_event_call(tu); 1621 1622 if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) { 1623 ret = -ENOMEM; 1624 goto error; 1625 } 1626 1627 return trace_probe_event_call(&tu->tp); 1628 error: 1629 free_trace_uprobe(tu); 1630 return ERR_PTR(ret); 1631 } 1632 1633 void destroy_local_trace_uprobe(struct trace_event_call *event_call) 1634 { 1635 struct trace_uprobe *tu; 1636 1637 tu = trace_uprobe_primary_from_call(event_call); 1638 1639 free_trace_uprobe(tu); 1640 } 1641 #endif /* CONFIG_PERF_EVENTS */ 1642 1643 /* Make a trace interface for controlling probe points */ 1644 static __init int init_uprobe_trace(void) 1645 { 1646 int ret; 1647 1648 ret = dyn_event_register(&trace_uprobe_ops); 1649 if (ret) 1650 return ret; 1651 1652 ret = tracing_init_dentry(); 1653 if (ret) 1654 return 0; 1655 1656 trace_create_file("uprobe_events", 0644, NULL, 1657 NULL, &uprobe_events_ops); 1658 /* Profile interface */ 1659 trace_create_file("uprobe_profile", 0444, NULL, 1660 NULL, &uprobe_profile_ops); 1661 return 0; 1662 } 1663 1664 fs_initcall(init_uprobe_trace); 1665