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