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(int argc, const char **argv); 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 [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 /* Parse uprobe offset. */ 621 ret = kstrtoul(arg, 0, &offset); 622 if (ret) { 623 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS); 624 goto fail_address_parse; 625 } 626 627 /* setup a probe */ 628 trace_probe_log_set_index(0); 629 if (event) { 630 ret = traceprobe_parse_event_name(&event, &group, buf, 631 event - argv[0]); 632 if (ret) 633 goto fail_address_parse; 634 } else { 635 char *tail; 636 char *ptr; 637 638 tail = kstrdup(kbasename(filename), GFP_KERNEL); 639 if (!tail) { 640 ret = -ENOMEM; 641 goto fail_address_parse; 642 } 643 644 ptr = strpbrk(tail, ".-_"); 645 if (ptr) 646 *ptr = '\0'; 647 648 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset); 649 event = buf; 650 kfree(tail); 651 } 652 653 argc -= 2; 654 argv += 2; 655 656 tu = alloc_trace_uprobe(group, event, argc, is_return); 657 if (IS_ERR(tu)) { 658 ret = PTR_ERR(tu); 659 /* This must return -ENOMEM otherwise there is a bug */ 660 WARN_ON_ONCE(ret != -ENOMEM); 661 goto fail_address_parse; 662 } 663 tu->offset = offset; 664 tu->ref_ctr_offset = ref_ctr_offset; 665 tu->path = path; 666 tu->filename = filename; 667 668 /* parse arguments */ 669 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { 670 tmp = kstrdup(argv[i], GFP_KERNEL); 671 if (!tmp) { 672 ret = -ENOMEM; 673 goto error; 674 } 675 676 trace_probe_log_set_index(i + 2); 677 ret = traceprobe_parse_probe_arg(&tu->tp, i, tmp, 678 is_return ? TPARG_FL_RETURN : 0); 679 kfree(tmp); 680 if (ret) 681 goto error; 682 } 683 684 ret = traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)); 685 if (ret < 0) 686 goto error; 687 688 ret = register_trace_uprobe(tu); 689 if (!ret) 690 goto out; 691 692 error: 693 free_trace_uprobe(tu); 694 out: 695 trace_probe_log_clear(); 696 return ret; 697 698 fail_address_parse: 699 trace_probe_log_clear(); 700 path_put(&path); 701 kfree(filename); 702 703 return ret; 704 } 705 706 static int create_or_delete_trace_uprobe(int argc, char **argv) 707 { 708 int ret; 709 710 if (argv[0][0] == '-') 711 return dyn_event_release(argc, argv, &trace_uprobe_ops); 712 713 ret = trace_uprobe_create(argc, (const char **)argv); 714 return ret == -ECANCELED ? -EINVAL : ret; 715 } 716 717 static int trace_uprobe_release(struct dyn_event *ev) 718 { 719 struct trace_uprobe *tu = to_trace_uprobe(ev); 720 721 return unregister_trace_uprobe(tu); 722 } 723 724 /* Probes listing interfaces */ 725 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev) 726 { 727 struct trace_uprobe *tu = to_trace_uprobe(ev); 728 char c = is_ret_probe(tu) ? 'r' : 'p'; 729 int i; 730 731 seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp), 732 trace_probe_name(&tu->tp), tu->filename, 733 (int)(sizeof(void *) * 2), tu->offset); 734 735 if (tu->ref_ctr_offset) 736 seq_printf(m, "(0x%lx)", tu->ref_ctr_offset); 737 738 for (i = 0; i < tu->tp.nr_args; i++) 739 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm); 740 741 seq_putc(m, '\n'); 742 return 0; 743 } 744 745 static int probes_seq_show(struct seq_file *m, void *v) 746 { 747 struct dyn_event *ev = v; 748 749 if (!is_trace_uprobe(ev)) 750 return 0; 751 752 return trace_uprobe_show(m, ev); 753 } 754 755 static const struct seq_operations probes_seq_op = { 756 .start = dyn_event_seq_start, 757 .next = dyn_event_seq_next, 758 .stop = dyn_event_seq_stop, 759 .show = probes_seq_show 760 }; 761 762 static int probes_open(struct inode *inode, struct file *file) 763 { 764 int ret; 765 766 ret = security_locked_down(LOCKDOWN_TRACEFS); 767 if (ret) 768 return ret; 769 770 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { 771 ret = dyn_events_release_all(&trace_uprobe_ops); 772 if (ret) 773 return ret; 774 } 775 776 return seq_open(file, &probes_seq_op); 777 } 778 779 static ssize_t probes_write(struct file *file, const char __user *buffer, 780 size_t count, loff_t *ppos) 781 { 782 return trace_parse_run_command(file, buffer, count, ppos, 783 create_or_delete_trace_uprobe); 784 } 785 786 static const struct file_operations uprobe_events_ops = { 787 .owner = THIS_MODULE, 788 .open = probes_open, 789 .read = seq_read, 790 .llseek = seq_lseek, 791 .release = seq_release, 792 .write = probes_write, 793 }; 794 795 /* Probes profiling interfaces */ 796 static int probes_profile_seq_show(struct seq_file *m, void *v) 797 { 798 struct dyn_event *ev = v; 799 struct trace_uprobe *tu; 800 801 if (!is_trace_uprobe(ev)) 802 return 0; 803 804 tu = to_trace_uprobe(ev); 805 seq_printf(m, " %s %-44s %15lu\n", tu->filename, 806 trace_probe_name(&tu->tp), tu->nhit); 807 return 0; 808 } 809 810 static const struct seq_operations profile_seq_op = { 811 .start = dyn_event_seq_start, 812 .next = dyn_event_seq_next, 813 .stop = dyn_event_seq_stop, 814 .show = probes_profile_seq_show 815 }; 816 817 static int profile_open(struct inode *inode, struct file *file) 818 { 819 int ret; 820 821 ret = security_locked_down(LOCKDOWN_TRACEFS); 822 if (ret) 823 return ret; 824 825 return seq_open(file, &profile_seq_op); 826 } 827 828 static const struct file_operations uprobe_profile_ops = { 829 .owner = THIS_MODULE, 830 .open = profile_open, 831 .read = seq_read, 832 .llseek = seq_lseek, 833 .release = seq_release, 834 }; 835 836 struct uprobe_cpu_buffer { 837 struct mutex mutex; 838 void *buf; 839 }; 840 static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer; 841 static int uprobe_buffer_refcnt; 842 843 static int uprobe_buffer_init(void) 844 { 845 int cpu, err_cpu; 846 847 uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer); 848 if (uprobe_cpu_buffer == NULL) 849 return -ENOMEM; 850 851 for_each_possible_cpu(cpu) { 852 struct page *p = alloc_pages_node(cpu_to_node(cpu), 853 GFP_KERNEL, 0); 854 if (p == NULL) { 855 err_cpu = cpu; 856 goto err; 857 } 858 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p); 859 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex); 860 } 861 862 return 0; 863 864 err: 865 for_each_possible_cpu(cpu) { 866 if (cpu == err_cpu) 867 break; 868 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf); 869 } 870 871 free_percpu(uprobe_cpu_buffer); 872 return -ENOMEM; 873 } 874 875 static int uprobe_buffer_enable(void) 876 { 877 int ret = 0; 878 879 BUG_ON(!mutex_is_locked(&event_mutex)); 880 881 if (uprobe_buffer_refcnt++ == 0) { 882 ret = uprobe_buffer_init(); 883 if (ret < 0) 884 uprobe_buffer_refcnt--; 885 } 886 887 return ret; 888 } 889 890 static void uprobe_buffer_disable(void) 891 { 892 int cpu; 893 894 BUG_ON(!mutex_is_locked(&event_mutex)); 895 896 if (--uprobe_buffer_refcnt == 0) { 897 for_each_possible_cpu(cpu) 898 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, 899 cpu)->buf); 900 901 free_percpu(uprobe_cpu_buffer); 902 uprobe_cpu_buffer = NULL; 903 } 904 } 905 906 static struct uprobe_cpu_buffer *uprobe_buffer_get(void) 907 { 908 struct uprobe_cpu_buffer *ucb; 909 int cpu; 910 911 cpu = raw_smp_processor_id(); 912 ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu); 913 914 /* 915 * Use per-cpu buffers for fastest access, but we might migrate 916 * so the mutex makes sure we have sole access to it. 917 */ 918 mutex_lock(&ucb->mutex); 919 920 return ucb; 921 } 922 923 static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb) 924 { 925 mutex_unlock(&ucb->mutex); 926 } 927 928 static void __uprobe_trace_func(struct trace_uprobe *tu, 929 unsigned long func, struct pt_regs *regs, 930 struct uprobe_cpu_buffer *ucb, int dsize, 931 struct trace_event_file *trace_file) 932 { 933 struct uprobe_trace_entry_head *entry; 934 struct trace_buffer *buffer; 935 struct ring_buffer_event *event; 936 void *data; 937 int size, esize; 938 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 939 940 WARN_ON(call != trace_file->event_call); 941 942 if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE)) 943 return; 944 945 if (trace_trigger_soft_disabled(trace_file)) 946 return; 947 948 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 949 size = esize + tu->tp.size + dsize; 950 event = trace_event_buffer_lock_reserve(&buffer, trace_file, 951 call->event.type, size, 0, 0); 952 if (!event) 953 return; 954 955 entry = ring_buffer_event_data(event); 956 if (is_ret_probe(tu)) { 957 entry->vaddr[0] = func; 958 entry->vaddr[1] = instruction_pointer(regs); 959 data = DATAOF_TRACE_ENTRY(entry, true); 960 } else { 961 entry->vaddr[0] = instruction_pointer(regs); 962 data = DATAOF_TRACE_ENTRY(entry, false); 963 } 964 965 memcpy(data, ucb->buf, tu->tp.size + dsize); 966 967 event_trigger_unlock_commit(trace_file, buffer, event, entry, 0, 0); 968 } 969 970 /* uprobe handler */ 971 static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs, 972 struct uprobe_cpu_buffer *ucb, int dsize) 973 { 974 struct event_file_link *link; 975 976 if (is_ret_probe(tu)) 977 return 0; 978 979 rcu_read_lock(); 980 trace_probe_for_each_link_rcu(link, &tu->tp) 981 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file); 982 rcu_read_unlock(); 983 984 return 0; 985 } 986 987 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func, 988 struct pt_regs *regs, 989 struct uprobe_cpu_buffer *ucb, int dsize) 990 { 991 struct event_file_link *link; 992 993 rcu_read_lock(); 994 trace_probe_for_each_link_rcu(link, &tu->tp) 995 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file); 996 rcu_read_unlock(); 997 } 998 999 /* Event entry printers */ 1000 static enum print_line_t 1001 print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) 1002 { 1003 struct uprobe_trace_entry_head *entry; 1004 struct trace_seq *s = &iter->seq; 1005 struct trace_uprobe *tu; 1006 u8 *data; 1007 1008 entry = (struct uprobe_trace_entry_head *)iter->ent; 1009 tu = trace_uprobe_primary_from_call( 1010 container_of(event, struct trace_event_call, event)); 1011 if (unlikely(!tu)) 1012 goto out; 1013 1014 if (is_ret_probe(tu)) { 1015 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)", 1016 trace_probe_name(&tu->tp), 1017 entry->vaddr[1], entry->vaddr[0]); 1018 data = DATAOF_TRACE_ENTRY(entry, true); 1019 } else { 1020 trace_seq_printf(s, "%s: (0x%lx)", 1021 trace_probe_name(&tu->tp), 1022 entry->vaddr[0]); 1023 data = DATAOF_TRACE_ENTRY(entry, false); 1024 } 1025 1026 if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0) 1027 goto out; 1028 1029 trace_seq_putc(s, '\n'); 1030 1031 out: 1032 return trace_handle_return(s); 1033 } 1034 1035 typedef bool (*filter_func_t)(struct uprobe_consumer *self, 1036 enum uprobe_filter_ctx ctx, 1037 struct mm_struct *mm); 1038 1039 static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter) 1040 { 1041 int ret; 1042 1043 tu->consumer.filter = filter; 1044 tu->inode = d_real_inode(tu->path.dentry); 1045 1046 if (tu->ref_ctr_offset) 1047 ret = uprobe_register_refctr(tu->inode, tu->offset, 1048 tu->ref_ctr_offset, &tu->consumer); 1049 else 1050 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer); 1051 1052 if (ret) 1053 tu->inode = NULL; 1054 1055 return ret; 1056 } 1057 1058 static void __probe_event_disable(struct trace_probe *tp) 1059 { 1060 struct trace_probe *pos; 1061 struct trace_uprobe *tu; 1062 1063 tu = container_of(tp, struct trace_uprobe, tp); 1064 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter)); 1065 1066 list_for_each_entry(pos, trace_probe_probe_list(tp), list) { 1067 tu = container_of(pos, struct trace_uprobe, tp); 1068 if (!tu->inode) 1069 continue; 1070 1071 uprobe_unregister(tu->inode, tu->offset, &tu->consumer); 1072 tu->inode = NULL; 1073 } 1074 } 1075 1076 static int probe_event_enable(struct trace_event_call *call, 1077 struct trace_event_file *file, filter_func_t filter) 1078 { 1079 struct trace_probe *pos, *tp; 1080 struct trace_uprobe *tu; 1081 bool enabled; 1082 int ret; 1083 1084 tp = trace_probe_primary_from_call(call); 1085 if (WARN_ON_ONCE(!tp)) 1086 return -ENODEV; 1087 enabled = trace_probe_is_enabled(tp); 1088 1089 /* This may also change "enabled" state */ 1090 if (file) { 1091 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE)) 1092 return -EINTR; 1093 1094 ret = trace_probe_add_file(tp, file); 1095 if (ret < 0) 1096 return ret; 1097 } else { 1098 if (trace_probe_test_flag(tp, TP_FLAG_TRACE)) 1099 return -EINTR; 1100 1101 trace_probe_set_flag(tp, TP_FLAG_PROFILE); 1102 } 1103 1104 tu = container_of(tp, struct trace_uprobe, tp); 1105 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter)); 1106 1107 if (enabled) 1108 return 0; 1109 1110 ret = uprobe_buffer_enable(); 1111 if (ret) 1112 goto err_flags; 1113 1114 list_for_each_entry(pos, trace_probe_probe_list(tp), list) { 1115 tu = container_of(pos, struct trace_uprobe, tp); 1116 ret = trace_uprobe_enable(tu, filter); 1117 if (ret) { 1118 __probe_event_disable(tp); 1119 goto err_buffer; 1120 } 1121 } 1122 1123 return 0; 1124 1125 err_buffer: 1126 uprobe_buffer_disable(); 1127 1128 err_flags: 1129 if (file) 1130 trace_probe_remove_file(tp, file); 1131 else 1132 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 1133 1134 return ret; 1135 } 1136 1137 static void probe_event_disable(struct trace_event_call *call, 1138 struct trace_event_file *file) 1139 { 1140 struct trace_probe *tp; 1141 1142 tp = trace_probe_primary_from_call(call); 1143 if (WARN_ON_ONCE(!tp)) 1144 return; 1145 1146 if (!trace_probe_is_enabled(tp)) 1147 return; 1148 1149 if (file) { 1150 if (trace_probe_remove_file(tp, file) < 0) 1151 return; 1152 1153 if (trace_probe_is_enabled(tp)) 1154 return; 1155 } else 1156 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 1157 1158 __probe_event_disable(tp); 1159 uprobe_buffer_disable(); 1160 } 1161 1162 static int uprobe_event_define_fields(struct trace_event_call *event_call) 1163 { 1164 int ret, size; 1165 struct uprobe_trace_entry_head field; 1166 struct trace_uprobe *tu; 1167 1168 tu = trace_uprobe_primary_from_call(event_call); 1169 if (unlikely(!tu)) 1170 return -ENODEV; 1171 1172 if (is_ret_probe(tu)) { 1173 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0); 1174 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0); 1175 size = SIZEOF_TRACE_ENTRY(true); 1176 } else { 1177 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0); 1178 size = SIZEOF_TRACE_ENTRY(false); 1179 } 1180 1181 return traceprobe_define_arg_fields(event_call, size, &tu->tp); 1182 } 1183 1184 #ifdef CONFIG_PERF_EVENTS 1185 static bool 1186 __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm) 1187 { 1188 struct perf_event *event; 1189 1190 if (filter->nr_systemwide) 1191 return true; 1192 1193 list_for_each_entry(event, &filter->perf_events, hw.tp_list) { 1194 if (event->hw.target->mm == mm) 1195 return true; 1196 } 1197 1198 return false; 1199 } 1200 1201 static inline bool 1202 trace_uprobe_filter_event(struct trace_uprobe_filter *filter, 1203 struct perf_event *event) 1204 { 1205 return __uprobe_perf_filter(filter, event->hw.target->mm); 1206 } 1207 1208 static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter, 1209 struct perf_event *event) 1210 { 1211 bool done; 1212 1213 write_lock(&filter->rwlock); 1214 if (event->hw.target) { 1215 list_del(&event->hw.tp_list); 1216 done = filter->nr_systemwide || 1217 (event->hw.target->flags & PF_EXITING) || 1218 trace_uprobe_filter_event(filter, event); 1219 } else { 1220 filter->nr_systemwide--; 1221 done = filter->nr_systemwide; 1222 } 1223 write_unlock(&filter->rwlock); 1224 1225 return done; 1226 } 1227 1228 /* This returns true if the filter always covers target mm */ 1229 static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter, 1230 struct perf_event *event) 1231 { 1232 bool done; 1233 1234 write_lock(&filter->rwlock); 1235 if (event->hw.target) { 1236 /* 1237 * event->parent != NULL means copy_process(), we can avoid 1238 * uprobe_apply(). current->mm must be probed and we can rely 1239 * on dup_mmap() which preserves the already installed bp's. 1240 * 1241 * attr.enable_on_exec means that exec/mmap will install the 1242 * breakpoints we need. 1243 */ 1244 done = filter->nr_systemwide || 1245 event->parent || event->attr.enable_on_exec || 1246 trace_uprobe_filter_event(filter, event); 1247 list_add(&event->hw.tp_list, &filter->perf_events); 1248 } else { 1249 done = filter->nr_systemwide; 1250 filter->nr_systemwide++; 1251 } 1252 write_unlock(&filter->rwlock); 1253 1254 return done; 1255 } 1256 1257 static int uprobe_perf_close(struct trace_event_call *call, 1258 struct perf_event *event) 1259 { 1260 struct trace_probe *pos, *tp; 1261 struct trace_uprobe *tu; 1262 int ret = 0; 1263 1264 tp = trace_probe_primary_from_call(call); 1265 if (WARN_ON_ONCE(!tp)) 1266 return -ENODEV; 1267 1268 tu = container_of(tp, struct trace_uprobe, tp); 1269 if (trace_uprobe_filter_remove(tu->tp.event->filter, event)) 1270 return 0; 1271 1272 list_for_each_entry(pos, trace_probe_probe_list(tp), list) { 1273 tu = container_of(pos, struct trace_uprobe, tp); 1274 ret = uprobe_apply(tu->inode, tu->offset, &tu->consumer, false); 1275 if (ret) 1276 break; 1277 } 1278 1279 return ret; 1280 } 1281 1282 static int uprobe_perf_open(struct trace_event_call *call, 1283 struct perf_event *event) 1284 { 1285 struct trace_probe *pos, *tp; 1286 struct trace_uprobe *tu; 1287 int err = 0; 1288 1289 tp = trace_probe_primary_from_call(call); 1290 if (WARN_ON_ONCE(!tp)) 1291 return -ENODEV; 1292 1293 tu = container_of(tp, struct trace_uprobe, tp); 1294 if (trace_uprobe_filter_add(tu->tp.event->filter, event)) 1295 return 0; 1296 1297 list_for_each_entry(pos, trace_probe_probe_list(tp), list) { 1298 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true); 1299 if (err) { 1300 uprobe_perf_close(call, event); 1301 break; 1302 } 1303 } 1304 1305 return err; 1306 } 1307 1308 static bool uprobe_perf_filter(struct uprobe_consumer *uc, 1309 enum uprobe_filter_ctx ctx, struct mm_struct *mm) 1310 { 1311 struct trace_uprobe_filter *filter; 1312 struct trace_uprobe *tu; 1313 int ret; 1314 1315 tu = container_of(uc, struct trace_uprobe, consumer); 1316 filter = tu->tp.event->filter; 1317 1318 read_lock(&filter->rwlock); 1319 ret = __uprobe_perf_filter(filter, mm); 1320 read_unlock(&filter->rwlock); 1321 1322 return ret; 1323 } 1324 1325 static void __uprobe_perf_func(struct trace_uprobe *tu, 1326 unsigned long func, struct pt_regs *regs, 1327 struct uprobe_cpu_buffer *ucb, int dsize) 1328 { 1329 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 1330 struct uprobe_trace_entry_head *entry; 1331 struct hlist_head *head; 1332 void *data; 1333 int size, esize; 1334 int rctx; 1335 1336 if (bpf_prog_array_valid(call)) { 1337 u32 ret; 1338 1339 preempt_disable(); 1340 ret = trace_call_bpf(call, regs); 1341 preempt_enable(); 1342 if (!ret) 1343 return; 1344 } 1345 1346 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1347 1348 size = esize + tu->tp.size + dsize; 1349 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32); 1350 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) 1351 return; 1352 1353 preempt_disable(); 1354 head = this_cpu_ptr(call->perf_events); 1355 if (hlist_empty(head)) 1356 goto out; 1357 1358 entry = perf_trace_buf_alloc(size, NULL, &rctx); 1359 if (!entry) 1360 goto out; 1361 1362 if (is_ret_probe(tu)) { 1363 entry->vaddr[0] = func; 1364 entry->vaddr[1] = instruction_pointer(regs); 1365 data = DATAOF_TRACE_ENTRY(entry, true); 1366 } else { 1367 entry->vaddr[0] = instruction_pointer(regs); 1368 data = DATAOF_TRACE_ENTRY(entry, false); 1369 } 1370 1371 memcpy(data, ucb->buf, tu->tp.size + dsize); 1372 1373 if (size - esize > tu->tp.size + dsize) { 1374 int len = tu->tp.size + dsize; 1375 1376 memset(data + len, 0, size - esize - len); 1377 } 1378 1379 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, 1380 head, NULL); 1381 out: 1382 preempt_enable(); 1383 } 1384 1385 /* uprobe profile handler */ 1386 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs, 1387 struct uprobe_cpu_buffer *ucb, int dsize) 1388 { 1389 if (!uprobe_perf_filter(&tu->consumer, 0, current->mm)) 1390 return UPROBE_HANDLER_REMOVE; 1391 1392 if (!is_ret_probe(tu)) 1393 __uprobe_perf_func(tu, 0, regs, ucb, dsize); 1394 return 0; 1395 } 1396 1397 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func, 1398 struct pt_regs *regs, 1399 struct uprobe_cpu_buffer *ucb, int dsize) 1400 { 1401 __uprobe_perf_func(tu, func, regs, ucb, dsize); 1402 } 1403 1404 int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type, 1405 const char **filename, u64 *probe_offset, 1406 bool perf_type_tracepoint) 1407 { 1408 const char *pevent = trace_event_name(event->tp_event); 1409 const char *group = event->tp_event->class->system; 1410 struct trace_uprobe *tu; 1411 1412 if (perf_type_tracepoint) 1413 tu = find_probe_event(pevent, group); 1414 else 1415 tu = trace_uprobe_primary_from_call(event->tp_event); 1416 if (!tu) 1417 return -EINVAL; 1418 1419 *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE 1420 : BPF_FD_TYPE_UPROBE; 1421 *filename = tu->filename; 1422 *probe_offset = tu->offset; 1423 return 0; 1424 } 1425 #endif /* CONFIG_PERF_EVENTS */ 1426 1427 static int 1428 trace_uprobe_register(struct trace_event_call *event, enum trace_reg type, 1429 void *data) 1430 { 1431 struct trace_event_file *file = data; 1432 1433 switch (type) { 1434 case TRACE_REG_REGISTER: 1435 return probe_event_enable(event, file, NULL); 1436 1437 case TRACE_REG_UNREGISTER: 1438 probe_event_disable(event, file); 1439 return 0; 1440 1441 #ifdef CONFIG_PERF_EVENTS 1442 case TRACE_REG_PERF_REGISTER: 1443 return probe_event_enable(event, NULL, uprobe_perf_filter); 1444 1445 case TRACE_REG_PERF_UNREGISTER: 1446 probe_event_disable(event, NULL); 1447 return 0; 1448 1449 case TRACE_REG_PERF_OPEN: 1450 return uprobe_perf_open(event, data); 1451 1452 case TRACE_REG_PERF_CLOSE: 1453 return uprobe_perf_close(event, data); 1454 1455 #endif 1456 default: 1457 return 0; 1458 } 1459 return 0; 1460 } 1461 1462 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) 1463 { 1464 struct trace_uprobe *tu; 1465 struct uprobe_dispatch_data udd; 1466 struct uprobe_cpu_buffer *ucb; 1467 int dsize, esize; 1468 int ret = 0; 1469 1470 1471 tu = container_of(con, struct trace_uprobe, consumer); 1472 tu->nhit++; 1473 1474 udd.tu = tu; 1475 udd.bp_addr = instruction_pointer(regs); 1476 1477 current->utask->vaddr = (unsigned long) &udd; 1478 1479 if (WARN_ON_ONCE(!uprobe_cpu_buffer)) 1480 return 0; 1481 1482 dsize = __get_data_size(&tu->tp, regs); 1483 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1484 1485 ucb = uprobe_buffer_get(); 1486 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize); 1487 1488 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) 1489 ret |= uprobe_trace_func(tu, regs, ucb, dsize); 1490 1491 #ifdef CONFIG_PERF_EVENTS 1492 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) 1493 ret |= uprobe_perf_func(tu, regs, ucb, dsize); 1494 #endif 1495 uprobe_buffer_put(ucb); 1496 return ret; 1497 } 1498 1499 static int uretprobe_dispatcher(struct uprobe_consumer *con, 1500 unsigned long func, struct pt_regs *regs) 1501 { 1502 struct trace_uprobe *tu; 1503 struct uprobe_dispatch_data udd; 1504 struct uprobe_cpu_buffer *ucb; 1505 int dsize, esize; 1506 1507 tu = container_of(con, struct trace_uprobe, consumer); 1508 1509 udd.tu = tu; 1510 udd.bp_addr = func; 1511 1512 current->utask->vaddr = (unsigned long) &udd; 1513 1514 if (WARN_ON_ONCE(!uprobe_cpu_buffer)) 1515 return 0; 1516 1517 dsize = __get_data_size(&tu->tp, regs); 1518 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1519 1520 ucb = uprobe_buffer_get(); 1521 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize); 1522 1523 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) 1524 uretprobe_trace_func(tu, func, regs, ucb, dsize); 1525 1526 #ifdef CONFIG_PERF_EVENTS 1527 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) 1528 uretprobe_perf_func(tu, func, regs, ucb, dsize); 1529 #endif 1530 uprobe_buffer_put(ucb); 1531 return 0; 1532 } 1533 1534 static struct trace_event_functions uprobe_funcs = { 1535 .trace = print_uprobe_event 1536 }; 1537 1538 static struct trace_event_fields uprobe_fields_array[] = { 1539 { .type = TRACE_FUNCTION_TYPE, 1540 .define_fields = uprobe_event_define_fields }, 1541 {} 1542 }; 1543 1544 static inline void init_trace_event_call(struct trace_uprobe *tu) 1545 { 1546 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 1547 call->event.funcs = &uprobe_funcs; 1548 call->class->fields_array = uprobe_fields_array; 1549 1550 call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY; 1551 call->class->reg = trace_uprobe_register; 1552 } 1553 1554 static int register_uprobe_event(struct trace_uprobe *tu) 1555 { 1556 init_trace_event_call(tu); 1557 1558 return trace_probe_register_event_call(&tu->tp); 1559 } 1560 1561 static int unregister_uprobe_event(struct trace_uprobe *tu) 1562 { 1563 return trace_probe_unregister_event_call(&tu->tp); 1564 } 1565 1566 #ifdef CONFIG_PERF_EVENTS 1567 struct trace_event_call * 1568 create_local_trace_uprobe(char *name, unsigned long offs, 1569 unsigned long ref_ctr_offset, bool is_return) 1570 { 1571 struct trace_uprobe *tu; 1572 struct path path; 1573 int ret; 1574 1575 ret = kern_path(name, LOOKUP_FOLLOW, &path); 1576 if (ret) 1577 return ERR_PTR(ret); 1578 1579 if (!d_is_reg(path.dentry)) { 1580 path_put(&path); 1581 return ERR_PTR(-EINVAL); 1582 } 1583 1584 /* 1585 * local trace_kprobes are not added to dyn_event, so they are never 1586 * searched in find_trace_kprobe(). Therefore, there is no concern of 1587 * duplicated name "DUMMY_EVENT" here. 1588 */ 1589 tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0, 1590 is_return); 1591 1592 if (IS_ERR(tu)) { 1593 pr_info("Failed to allocate trace_uprobe.(%d)\n", 1594 (int)PTR_ERR(tu)); 1595 path_put(&path); 1596 return ERR_CAST(tu); 1597 } 1598 1599 tu->offset = offs; 1600 tu->path = path; 1601 tu->ref_ctr_offset = ref_ctr_offset; 1602 tu->filename = kstrdup(name, GFP_KERNEL); 1603 init_trace_event_call(tu); 1604 1605 if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) { 1606 ret = -ENOMEM; 1607 goto error; 1608 } 1609 1610 return trace_probe_event_call(&tu->tp); 1611 error: 1612 free_trace_uprobe(tu); 1613 return ERR_PTR(ret); 1614 } 1615 1616 void destroy_local_trace_uprobe(struct trace_event_call *event_call) 1617 { 1618 struct trace_uprobe *tu; 1619 1620 tu = trace_uprobe_primary_from_call(event_call); 1621 1622 free_trace_uprobe(tu); 1623 } 1624 #endif /* CONFIG_PERF_EVENTS */ 1625 1626 /* Make a trace interface for controling probe points */ 1627 static __init int init_uprobe_trace(void) 1628 { 1629 struct dentry *d_tracer; 1630 int ret; 1631 1632 ret = dyn_event_register(&trace_uprobe_ops); 1633 if (ret) 1634 return ret; 1635 1636 d_tracer = tracing_init_dentry(); 1637 if (IS_ERR(d_tracer)) 1638 return 0; 1639 1640 trace_create_file("uprobe_events", 0644, d_tracer, 1641 NULL, &uprobe_events_ops); 1642 /* Profile interface */ 1643 trace_create_file("uprobe_profile", 0444, d_tracer, 1644 NULL, &uprobe_profile_ops); 1645 return 0; 1646 } 1647 1648 fs_initcall(init_uprobe_trace); 1649