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 20 #include "trace_dynevent.h" 21 #include "trace_probe.h" 22 #include "trace_probe_tmpl.h" 23 24 #define UPROBE_EVENT_SYSTEM "uprobes" 25 26 struct uprobe_trace_entry_head { 27 struct trace_entry ent; 28 unsigned long vaddr[]; 29 }; 30 31 #define SIZEOF_TRACE_ENTRY(is_return) \ 32 (sizeof(struct uprobe_trace_entry_head) + \ 33 sizeof(unsigned long) * (is_return ? 2 : 1)) 34 35 #define DATAOF_TRACE_ENTRY(entry, is_return) \ 36 ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return)) 37 38 static int trace_uprobe_create(const char *raw_command); 39 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev); 40 static int trace_uprobe_release(struct dyn_event *ev); 41 static bool trace_uprobe_is_busy(struct dyn_event *ev); 42 static bool trace_uprobe_match(const char *system, const char *event, 43 int argc, const char **argv, struct dyn_event *ev); 44 45 static struct dyn_event_operations trace_uprobe_ops = { 46 .create = trace_uprobe_create, 47 .show = trace_uprobe_show, 48 .is_busy = trace_uprobe_is_busy, 49 .free = trace_uprobe_release, 50 .match = trace_uprobe_match, 51 }; 52 53 /* 54 * uprobe event core functions 55 */ 56 struct trace_uprobe { 57 struct dyn_event devent; 58 struct uprobe_consumer consumer; 59 struct path path; 60 struct inode *inode; 61 char *filename; 62 unsigned long offset; 63 unsigned long ref_ctr_offset; 64 unsigned long nhit; 65 struct trace_probe tp; 66 }; 67 68 static bool is_trace_uprobe(struct dyn_event *ev) 69 { 70 return ev->ops == &trace_uprobe_ops; 71 } 72 73 static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev) 74 { 75 return container_of(ev, struct trace_uprobe, devent); 76 } 77 78 /** 79 * for_each_trace_uprobe - iterate over the trace_uprobe list 80 * @pos: the struct trace_uprobe * for each entry 81 * @dpos: the struct dyn_event * to use as a loop cursor 82 */ 83 #define for_each_trace_uprobe(pos, dpos) \ 84 for_each_dyn_event(dpos) \ 85 if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos))) 86 87 static int register_uprobe_event(struct trace_uprobe *tu); 88 static int unregister_uprobe_event(struct trace_uprobe *tu); 89 90 struct uprobe_dispatch_data { 91 struct trace_uprobe *tu; 92 unsigned long bp_addr; 93 }; 94 95 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs); 96 static int uretprobe_dispatcher(struct uprobe_consumer *con, 97 unsigned long func, struct pt_regs *regs); 98 99 #ifdef CONFIG_STACK_GROWSUP 100 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) 101 { 102 return addr - (n * sizeof(long)); 103 } 104 #else 105 static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) 106 { 107 return addr + (n * sizeof(long)); 108 } 109 #endif 110 111 static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n) 112 { 113 unsigned long ret; 114 unsigned long addr = user_stack_pointer(regs); 115 116 addr = adjust_stack_addr(addr, n); 117 118 if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret))) 119 return 0; 120 121 return ret; 122 } 123 124 /* 125 * Uprobes-specific fetch functions 126 */ 127 static nokprobe_inline int 128 probe_mem_read(void *dest, void *src, size_t size) 129 { 130 void __user *vaddr = (void __force __user *)src; 131 132 return copy_from_user(dest, vaddr, size) ? -EFAULT : 0; 133 } 134 135 static nokprobe_inline int 136 probe_mem_read_user(void *dest, void *src, size_t size) 137 { 138 return probe_mem_read(dest, src, size); 139 } 140 141 /* 142 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max 143 * length and relative data location. 144 */ 145 static nokprobe_inline int 146 fetch_store_string(unsigned long addr, void *dest, void *base) 147 { 148 long ret; 149 u32 loc = *(u32 *)dest; 150 int maxlen = get_loc_len(loc); 151 u8 *dst = get_loc_data(dest, base); 152 void __user *src = (void __force __user *) addr; 153 154 if (unlikely(!maxlen)) 155 return -ENOMEM; 156 157 if (addr == FETCH_TOKEN_COMM) 158 ret = strlcpy(dst, current->comm, maxlen); 159 else 160 ret = strncpy_from_user(dst, src, maxlen); 161 if (ret >= 0) { 162 if (ret == maxlen) 163 dst[ret - 1] = '\0'; 164 else 165 /* 166 * Include the terminating null byte. In this case it 167 * was copied by strncpy_from_user but not accounted 168 * for in ret. 169 */ 170 ret++; 171 *(u32 *)dest = make_data_loc(ret, (void *)dst - base); 172 } 173 174 return ret; 175 } 176 177 static nokprobe_inline int 178 fetch_store_string_user(unsigned long addr, void *dest, void *base) 179 { 180 return fetch_store_string(addr, dest, base); 181 } 182 183 /* Return the length of string -- including null terminal byte */ 184 static nokprobe_inline int 185 fetch_store_strlen(unsigned long addr) 186 { 187 int len; 188 void __user *vaddr = (void __force __user *) addr; 189 190 if (addr == FETCH_TOKEN_COMM) 191 len = strlen(current->comm) + 1; 192 else 193 len = strnlen_user(vaddr, MAX_STRING_SIZE); 194 195 return (len > MAX_STRING_SIZE) ? 0 : len; 196 } 197 198 static nokprobe_inline int 199 fetch_store_strlen_user(unsigned long addr) 200 { 201 return fetch_store_strlen(addr); 202 } 203 204 static unsigned long translate_user_vaddr(unsigned long file_offset) 205 { 206 unsigned long base_addr; 207 struct uprobe_dispatch_data *udd; 208 209 udd = (void *) current->utask->vaddr; 210 211 base_addr = udd->bp_addr - udd->tu->offset; 212 return base_addr + file_offset; 213 } 214 215 /* Note that we don't verify it, since the code does not come from user space */ 216 static int 217 process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, 218 void *base) 219 { 220 struct pt_regs *regs = rec; 221 unsigned long val; 222 223 /* 1st stage: get value from context */ 224 switch (code->op) { 225 case FETCH_OP_REG: 226 val = regs_get_register(regs, code->param); 227 break; 228 case FETCH_OP_STACK: 229 val = get_user_stack_nth(regs, code->param); 230 break; 231 case FETCH_OP_STACKP: 232 val = user_stack_pointer(regs); 233 break; 234 case FETCH_OP_RETVAL: 235 val = regs_return_value(regs); 236 break; 237 case FETCH_OP_IMM: 238 val = code->immediate; 239 break; 240 case FETCH_OP_COMM: 241 val = FETCH_TOKEN_COMM; 242 break; 243 case FETCH_OP_DATA: 244 val = (unsigned long)code->data; 245 break; 246 case FETCH_OP_FOFFS: 247 val = translate_user_vaddr(code->immediate); 248 break; 249 default: 250 return -EILSEQ; 251 } 252 code++; 253 254 return process_fetch_insn_bottom(code, val, dest, base); 255 } 256 NOKPROBE_SYMBOL(process_fetch_insn) 257 258 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter) 259 { 260 rwlock_init(&filter->rwlock); 261 filter->nr_systemwide = 0; 262 INIT_LIST_HEAD(&filter->perf_events); 263 } 264 265 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter) 266 { 267 return !filter->nr_systemwide && list_empty(&filter->perf_events); 268 } 269 270 static inline bool is_ret_probe(struct trace_uprobe *tu) 271 { 272 return tu->consumer.ret_handler != NULL; 273 } 274 275 static bool trace_uprobe_is_busy(struct dyn_event *ev) 276 { 277 struct trace_uprobe *tu = to_trace_uprobe(ev); 278 279 return trace_probe_is_enabled(&tu->tp); 280 } 281 282 static bool trace_uprobe_match_command_head(struct trace_uprobe *tu, 283 int argc, const char **argv) 284 { 285 char buf[MAX_ARGSTR_LEN + 1]; 286 int len; 287 288 if (!argc) 289 return true; 290 291 len = strlen(tu->filename); 292 if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':') 293 return false; 294 295 if (tu->ref_ctr_offset == 0) 296 snprintf(buf, sizeof(buf), "0x%0*lx", 297 (int)(sizeof(void *) * 2), tu->offset); 298 else 299 snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)", 300 (int)(sizeof(void *) * 2), tu->offset, 301 tu->ref_ctr_offset); 302 if (strcmp(buf, &argv[0][len + 1])) 303 return false; 304 305 argc--; argv++; 306 307 return trace_probe_match_command_args(&tu->tp, argc, argv); 308 } 309 310 static bool trace_uprobe_match(const char *system, const char *event, 311 int argc, const char **argv, struct dyn_event *ev) 312 { 313 struct trace_uprobe *tu = to_trace_uprobe(ev); 314 315 return (event[0] == '\0' || 316 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 char gbuf[MAX_EVENT_NAME_LEN]; 545 enum probe_print_type ptype; 546 struct path path; 547 unsigned long offset, ref_ctr_offset; 548 bool is_return = false; 549 int i, ret; 550 551 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, gbuf, 650 event - argv[0]); 651 if (ret) 652 goto fail_address_parse; 653 } 654 655 if (!event) { 656 char *tail; 657 char *ptr; 658 659 tail = kstrdup(kbasename(filename), GFP_KERNEL); 660 if (!tail) { 661 ret = -ENOMEM; 662 goto fail_address_parse; 663 } 664 665 ptr = strpbrk(tail, ".-_"); 666 if (ptr) 667 *ptr = '\0'; 668 669 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset); 670 event = buf; 671 kfree(tail); 672 } 673 674 argc -= 2; 675 argv += 2; 676 677 tu = alloc_trace_uprobe(group, event, argc, is_return); 678 if (IS_ERR(tu)) { 679 ret = PTR_ERR(tu); 680 /* This must return -ENOMEM otherwise there is a bug */ 681 WARN_ON_ONCE(ret != -ENOMEM); 682 goto fail_address_parse; 683 } 684 tu->offset = offset; 685 tu->ref_ctr_offset = ref_ctr_offset; 686 tu->path = path; 687 tu->filename = filename; 688 689 /* parse arguments */ 690 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { 691 trace_probe_log_set_index(i + 2); 692 ret = traceprobe_parse_probe_arg(&tu->tp, i, argv[i], 693 is_return ? TPARG_FL_RETURN : 0); 694 if (ret) 695 goto error; 696 } 697 698 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; 699 ret = traceprobe_set_print_fmt(&tu->tp, ptype); 700 if (ret < 0) 701 goto error; 702 703 ret = register_trace_uprobe(tu); 704 if (!ret) 705 goto out; 706 707 error: 708 free_trace_uprobe(tu); 709 out: 710 trace_probe_log_clear(); 711 return ret; 712 713 fail_address_parse: 714 trace_probe_log_clear(); 715 path_put(&path); 716 kfree(filename); 717 718 return ret; 719 } 720 721 int trace_uprobe_create(const char *raw_command) 722 { 723 return trace_probe_create(raw_command, __trace_uprobe_create); 724 } 725 726 static int create_or_delete_trace_uprobe(const char *raw_command) 727 { 728 int ret; 729 730 if (raw_command[0] == '-') 731 return dyn_event_release(raw_command, &trace_uprobe_ops); 732 733 ret = trace_uprobe_create(raw_command); 734 return ret == -ECANCELED ? -EINVAL : ret; 735 } 736 737 static int trace_uprobe_release(struct dyn_event *ev) 738 { 739 struct trace_uprobe *tu = to_trace_uprobe(ev); 740 741 return unregister_trace_uprobe(tu); 742 } 743 744 /* Probes listing interfaces */ 745 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev) 746 { 747 struct trace_uprobe *tu = to_trace_uprobe(ev); 748 char c = is_ret_probe(tu) ? 'r' : 'p'; 749 int i; 750 751 seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp), 752 trace_probe_name(&tu->tp), tu->filename, 753 (int)(sizeof(void *) * 2), tu->offset); 754 755 if (tu->ref_ctr_offset) 756 seq_printf(m, "(0x%lx)", tu->ref_ctr_offset); 757 758 for (i = 0; i < tu->tp.nr_args; i++) 759 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm); 760 761 seq_putc(m, '\n'); 762 return 0; 763 } 764 765 static int probes_seq_show(struct seq_file *m, void *v) 766 { 767 struct dyn_event *ev = v; 768 769 if (!is_trace_uprobe(ev)) 770 return 0; 771 772 return trace_uprobe_show(m, ev); 773 } 774 775 static const struct seq_operations probes_seq_op = { 776 .start = dyn_event_seq_start, 777 .next = dyn_event_seq_next, 778 .stop = dyn_event_seq_stop, 779 .show = probes_seq_show 780 }; 781 782 static int probes_open(struct inode *inode, struct file *file) 783 { 784 int ret; 785 786 ret = security_locked_down(LOCKDOWN_TRACEFS); 787 if (ret) 788 return ret; 789 790 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { 791 ret = dyn_events_release_all(&trace_uprobe_ops); 792 if (ret) 793 return ret; 794 } 795 796 return seq_open(file, &probes_seq_op); 797 } 798 799 static ssize_t probes_write(struct file *file, const char __user *buffer, 800 size_t count, loff_t *ppos) 801 { 802 return trace_parse_run_command(file, buffer, count, ppos, 803 create_or_delete_trace_uprobe); 804 } 805 806 static const struct file_operations uprobe_events_ops = { 807 .owner = THIS_MODULE, 808 .open = probes_open, 809 .read = seq_read, 810 .llseek = seq_lseek, 811 .release = seq_release, 812 .write = probes_write, 813 }; 814 815 /* Probes profiling interfaces */ 816 static int probes_profile_seq_show(struct seq_file *m, void *v) 817 { 818 struct dyn_event *ev = v; 819 struct trace_uprobe *tu; 820 821 if (!is_trace_uprobe(ev)) 822 return 0; 823 824 tu = to_trace_uprobe(ev); 825 seq_printf(m, " %s %-44s %15lu\n", tu->filename, 826 trace_probe_name(&tu->tp), tu->nhit); 827 return 0; 828 } 829 830 static const struct seq_operations profile_seq_op = { 831 .start = dyn_event_seq_start, 832 .next = dyn_event_seq_next, 833 .stop = dyn_event_seq_stop, 834 .show = probes_profile_seq_show 835 }; 836 837 static int profile_open(struct inode *inode, struct file *file) 838 { 839 int ret; 840 841 ret = security_locked_down(LOCKDOWN_TRACEFS); 842 if (ret) 843 return ret; 844 845 return seq_open(file, &profile_seq_op); 846 } 847 848 static const struct file_operations uprobe_profile_ops = { 849 .owner = THIS_MODULE, 850 .open = profile_open, 851 .read = seq_read, 852 .llseek = seq_lseek, 853 .release = seq_release, 854 }; 855 856 struct uprobe_cpu_buffer { 857 struct mutex mutex; 858 void *buf; 859 }; 860 static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer; 861 static int uprobe_buffer_refcnt; 862 863 static int uprobe_buffer_init(void) 864 { 865 int cpu, err_cpu; 866 867 uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer); 868 if (uprobe_cpu_buffer == NULL) 869 return -ENOMEM; 870 871 for_each_possible_cpu(cpu) { 872 struct page *p = alloc_pages_node(cpu_to_node(cpu), 873 GFP_KERNEL, 0); 874 if (p == NULL) { 875 err_cpu = cpu; 876 goto err; 877 } 878 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p); 879 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex); 880 } 881 882 return 0; 883 884 err: 885 for_each_possible_cpu(cpu) { 886 if (cpu == err_cpu) 887 break; 888 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf); 889 } 890 891 free_percpu(uprobe_cpu_buffer); 892 return -ENOMEM; 893 } 894 895 static int uprobe_buffer_enable(void) 896 { 897 int ret = 0; 898 899 BUG_ON(!mutex_is_locked(&event_mutex)); 900 901 if (uprobe_buffer_refcnt++ == 0) { 902 ret = uprobe_buffer_init(); 903 if (ret < 0) 904 uprobe_buffer_refcnt--; 905 } 906 907 return ret; 908 } 909 910 static void uprobe_buffer_disable(void) 911 { 912 int cpu; 913 914 BUG_ON(!mutex_is_locked(&event_mutex)); 915 916 if (--uprobe_buffer_refcnt == 0) { 917 for_each_possible_cpu(cpu) 918 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, 919 cpu)->buf); 920 921 free_percpu(uprobe_cpu_buffer); 922 uprobe_cpu_buffer = NULL; 923 } 924 } 925 926 static struct uprobe_cpu_buffer *uprobe_buffer_get(void) 927 { 928 struct uprobe_cpu_buffer *ucb; 929 int cpu; 930 931 cpu = raw_smp_processor_id(); 932 ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu); 933 934 /* 935 * Use per-cpu buffers for fastest access, but we might migrate 936 * so the mutex makes sure we have sole access to it. 937 */ 938 mutex_lock(&ucb->mutex); 939 940 return ucb; 941 } 942 943 static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb) 944 { 945 mutex_unlock(&ucb->mutex); 946 } 947 948 static void __uprobe_trace_func(struct trace_uprobe *tu, 949 unsigned long func, struct pt_regs *regs, 950 struct uprobe_cpu_buffer *ucb, int dsize, 951 struct trace_event_file *trace_file) 952 { 953 struct uprobe_trace_entry_head *entry; 954 struct trace_event_buffer fbuffer; 955 void *data; 956 int size, esize; 957 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 958 959 WARN_ON(call != trace_file->event_call); 960 961 if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE)) 962 return; 963 964 if (trace_trigger_soft_disabled(trace_file)) 965 return; 966 967 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 968 size = esize + tu->tp.size + dsize; 969 entry = trace_event_buffer_reserve(&fbuffer, trace_file, size); 970 if (!entry) 971 return; 972 973 if (is_ret_probe(tu)) { 974 entry->vaddr[0] = func; 975 entry->vaddr[1] = instruction_pointer(regs); 976 data = DATAOF_TRACE_ENTRY(entry, true); 977 } else { 978 entry->vaddr[0] = instruction_pointer(regs); 979 data = DATAOF_TRACE_ENTRY(entry, false); 980 } 981 982 memcpy(data, ucb->buf, tu->tp.size + dsize); 983 984 trace_event_buffer_commit(&fbuffer); 985 } 986 987 /* uprobe handler */ 988 static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs, 989 struct uprobe_cpu_buffer *ucb, int dsize) 990 { 991 struct event_file_link *link; 992 993 if (is_ret_probe(tu)) 994 return 0; 995 996 rcu_read_lock(); 997 trace_probe_for_each_link_rcu(link, &tu->tp) 998 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file); 999 rcu_read_unlock(); 1000 1001 return 0; 1002 } 1003 1004 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func, 1005 struct pt_regs *regs, 1006 struct uprobe_cpu_buffer *ucb, int dsize) 1007 { 1008 struct event_file_link *link; 1009 1010 rcu_read_lock(); 1011 trace_probe_for_each_link_rcu(link, &tu->tp) 1012 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file); 1013 rcu_read_unlock(); 1014 } 1015 1016 /* Event entry printers */ 1017 static enum print_line_t 1018 print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) 1019 { 1020 struct uprobe_trace_entry_head *entry; 1021 struct trace_seq *s = &iter->seq; 1022 struct trace_uprobe *tu; 1023 u8 *data; 1024 1025 entry = (struct uprobe_trace_entry_head *)iter->ent; 1026 tu = trace_uprobe_primary_from_call( 1027 container_of(event, struct trace_event_call, event)); 1028 if (unlikely(!tu)) 1029 goto out; 1030 1031 if (is_ret_probe(tu)) { 1032 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)", 1033 trace_probe_name(&tu->tp), 1034 entry->vaddr[1], entry->vaddr[0]); 1035 data = DATAOF_TRACE_ENTRY(entry, true); 1036 } else { 1037 trace_seq_printf(s, "%s: (0x%lx)", 1038 trace_probe_name(&tu->tp), 1039 entry->vaddr[0]); 1040 data = DATAOF_TRACE_ENTRY(entry, false); 1041 } 1042 1043 if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0) 1044 goto out; 1045 1046 trace_seq_putc(s, '\n'); 1047 1048 out: 1049 return trace_handle_return(s); 1050 } 1051 1052 typedef bool (*filter_func_t)(struct uprobe_consumer *self, 1053 enum uprobe_filter_ctx ctx, 1054 struct mm_struct *mm); 1055 1056 static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter) 1057 { 1058 int ret; 1059 1060 tu->consumer.filter = filter; 1061 tu->inode = d_real_inode(tu->path.dentry); 1062 1063 if (tu->ref_ctr_offset) 1064 ret = uprobe_register_refctr(tu->inode, tu->offset, 1065 tu->ref_ctr_offset, &tu->consumer); 1066 else 1067 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer); 1068 1069 if (ret) 1070 tu->inode = NULL; 1071 1072 return ret; 1073 } 1074 1075 static void __probe_event_disable(struct trace_probe *tp) 1076 { 1077 struct trace_uprobe *tu; 1078 1079 tu = container_of(tp, struct trace_uprobe, tp); 1080 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter)); 1081 1082 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1083 if (!tu->inode) 1084 continue; 1085 1086 uprobe_unregister(tu->inode, tu->offset, &tu->consumer); 1087 tu->inode = NULL; 1088 } 1089 } 1090 1091 static int probe_event_enable(struct trace_event_call *call, 1092 struct trace_event_file *file, filter_func_t filter) 1093 { 1094 struct trace_probe *tp; 1095 struct trace_uprobe *tu; 1096 bool enabled; 1097 int ret; 1098 1099 tp = trace_probe_primary_from_call(call); 1100 if (WARN_ON_ONCE(!tp)) 1101 return -ENODEV; 1102 enabled = trace_probe_is_enabled(tp); 1103 1104 /* This may also change "enabled" state */ 1105 if (file) { 1106 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE)) 1107 return -EINTR; 1108 1109 ret = trace_probe_add_file(tp, file); 1110 if (ret < 0) 1111 return ret; 1112 } else { 1113 if (trace_probe_test_flag(tp, TP_FLAG_TRACE)) 1114 return -EINTR; 1115 1116 trace_probe_set_flag(tp, TP_FLAG_PROFILE); 1117 } 1118 1119 tu = container_of(tp, struct trace_uprobe, tp); 1120 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter)); 1121 1122 if (enabled) 1123 return 0; 1124 1125 ret = uprobe_buffer_enable(); 1126 if (ret) 1127 goto err_flags; 1128 1129 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1130 ret = trace_uprobe_enable(tu, filter); 1131 if (ret) { 1132 __probe_event_disable(tp); 1133 goto err_buffer; 1134 } 1135 } 1136 1137 return 0; 1138 1139 err_buffer: 1140 uprobe_buffer_disable(); 1141 1142 err_flags: 1143 if (file) 1144 trace_probe_remove_file(tp, file); 1145 else 1146 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 1147 1148 return ret; 1149 } 1150 1151 static void probe_event_disable(struct trace_event_call *call, 1152 struct trace_event_file *file) 1153 { 1154 struct trace_probe *tp; 1155 1156 tp = trace_probe_primary_from_call(call); 1157 if (WARN_ON_ONCE(!tp)) 1158 return; 1159 1160 if (!trace_probe_is_enabled(tp)) 1161 return; 1162 1163 if (file) { 1164 if (trace_probe_remove_file(tp, file) < 0) 1165 return; 1166 1167 if (trace_probe_is_enabled(tp)) 1168 return; 1169 } else 1170 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 1171 1172 __probe_event_disable(tp); 1173 uprobe_buffer_disable(); 1174 } 1175 1176 static int uprobe_event_define_fields(struct trace_event_call *event_call) 1177 { 1178 int ret, size; 1179 struct uprobe_trace_entry_head field; 1180 struct trace_uprobe *tu; 1181 1182 tu = trace_uprobe_primary_from_call(event_call); 1183 if (unlikely(!tu)) 1184 return -ENODEV; 1185 1186 if (is_ret_probe(tu)) { 1187 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0); 1188 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0); 1189 size = SIZEOF_TRACE_ENTRY(true); 1190 } else { 1191 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0); 1192 size = SIZEOF_TRACE_ENTRY(false); 1193 } 1194 1195 return traceprobe_define_arg_fields(event_call, size, &tu->tp); 1196 } 1197 1198 #ifdef CONFIG_PERF_EVENTS 1199 static bool 1200 __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm) 1201 { 1202 struct perf_event *event; 1203 1204 if (filter->nr_systemwide) 1205 return true; 1206 1207 list_for_each_entry(event, &filter->perf_events, hw.tp_list) { 1208 if (event->hw.target->mm == mm) 1209 return true; 1210 } 1211 1212 return false; 1213 } 1214 1215 static inline bool 1216 trace_uprobe_filter_event(struct trace_uprobe_filter *filter, 1217 struct perf_event *event) 1218 { 1219 return __uprobe_perf_filter(filter, event->hw.target->mm); 1220 } 1221 1222 static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter, 1223 struct perf_event *event) 1224 { 1225 bool done; 1226 1227 write_lock(&filter->rwlock); 1228 if (event->hw.target) { 1229 list_del(&event->hw.tp_list); 1230 done = filter->nr_systemwide || 1231 (event->hw.target->flags & PF_EXITING) || 1232 trace_uprobe_filter_event(filter, event); 1233 } else { 1234 filter->nr_systemwide--; 1235 done = filter->nr_systemwide; 1236 } 1237 write_unlock(&filter->rwlock); 1238 1239 return done; 1240 } 1241 1242 /* This returns true if the filter always covers target mm */ 1243 static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter, 1244 struct perf_event *event) 1245 { 1246 bool done; 1247 1248 write_lock(&filter->rwlock); 1249 if (event->hw.target) { 1250 /* 1251 * event->parent != NULL means copy_process(), we can avoid 1252 * uprobe_apply(). current->mm must be probed and we can rely 1253 * on dup_mmap() which preserves the already installed bp's. 1254 * 1255 * attr.enable_on_exec means that exec/mmap will install the 1256 * breakpoints we need. 1257 */ 1258 done = filter->nr_systemwide || 1259 event->parent || event->attr.enable_on_exec || 1260 trace_uprobe_filter_event(filter, event); 1261 list_add(&event->hw.tp_list, &filter->perf_events); 1262 } else { 1263 done = filter->nr_systemwide; 1264 filter->nr_systemwide++; 1265 } 1266 write_unlock(&filter->rwlock); 1267 1268 return done; 1269 } 1270 1271 static int uprobe_perf_close(struct trace_event_call *call, 1272 struct perf_event *event) 1273 { 1274 struct trace_probe *tp; 1275 struct trace_uprobe *tu; 1276 int ret = 0; 1277 1278 tp = trace_probe_primary_from_call(call); 1279 if (WARN_ON_ONCE(!tp)) 1280 return -ENODEV; 1281 1282 tu = container_of(tp, struct trace_uprobe, tp); 1283 if (trace_uprobe_filter_remove(tu->tp.event->filter, event)) 1284 return 0; 1285 1286 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1287 ret = uprobe_apply(tu->inode, tu->offset, &tu->consumer, false); 1288 if (ret) 1289 break; 1290 } 1291 1292 return ret; 1293 } 1294 1295 static int uprobe_perf_open(struct trace_event_call *call, 1296 struct perf_event *event) 1297 { 1298 struct trace_probe *tp; 1299 struct trace_uprobe *tu; 1300 int err = 0; 1301 1302 tp = trace_probe_primary_from_call(call); 1303 if (WARN_ON_ONCE(!tp)) 1304 return -ENODEV; 1305 1306 tu = container_of(tp, struct trace_uprobe, tp); 1307 if (trace_uprobe_filter_add(tu->tp.event->filter, event)) 1308 return 0; 1309 1310 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1311 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true); 1312 if (err) { 1313 uprobe_perf_close(call, event); 1314 break; 1315 } 1316 } 1317 1318 return err; 1319 } 1320 1321 static bool uprobe_perf_filter(struct uprobe_consumer *uc, 1322 enum uprobe_filter_ctx ctx, struct mm_struct *mm) 1323 { 1324 struct trace_uprobe_filter *filter; 1325 struct trace_uprobe *tu; 1326 int ret; 1327 1328 tu = container_of(uc, struct trace_uprobe, consumer); 1329 filter = tu->tp.event->filter; 1330 1331 read_lock(&filter->rwlock); 1332 ret = __uprobe_perf_filter(filter, mm); 1333 read_unlock(&filter->rwlock); 1334 1335 return ret; 1336 } 1337 1338 static void __uprobe_perf_func(struct trace_uprobe *tu, 1339 unsigned long func, struct pt_regs *regs, 1340 struct uprobe_cpu_buffer *ucb, int dsize) 1341 { 1342 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 1343 struct uprobe_trace_entry_head *entry; 1344 struct hlist_head *head; 1345 void *data; 1346 int size, esize; 1347 int rctx; 1348 1349 if (bpf_prog_array_valid(call)) { 1350 u32 ret; 1351 1352 preempt_disable(); 1353 ret = trace_call_bpf(call, regs); 1354 preempt_enable(); 1355 if (!ret) 1356 return; 1357 } 1358 1359 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1360 1361 size = esize + tu->tp.size + dsize; 1362 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32); 1363 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) 1364 return; 1365 1366 preempt_disable(); 1367 head = this_cpu_ptr(call->perf_events); 1368 if (hlist_empty(head)) 1369 goto out; 1370 1371 entry = perf_trace_buf_alloc(size, NULL, &rctx); 1372 if (!entry) 1373 goto out; 1374 1375 if (is_ret_probe(tu)) { 1376 entry->vaddr[0] = func; 1377 entry->vaddr[1] = instruction_pointer(regs); 1378 data = DATAOF_TRACE_ENTRY(entry, true); 1379 } else { 1380 entry->vaddr[0] = instruction_pointer(regs); 1381 data = DATAOF_TRACE_ENTRY(entry, false); 1382 } 1383 1384 memcpy(data, ucb->buf, tu->tp.size + dsize); 1385 1386 if (size - esize > tu->tp.size + dsize) { 1387 int len = tu->tp.size + dsize; 1388 1389 memset(data + len, 0, size - esize - len); 1390 } 1391 1392 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, 1393 head, NULL); 1394 out: 1395 preempt_enable(); 1396 } 1397 1398 /* uprobe profile handler */ 1399 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs, 1400 struct uprobe_cpu_buffer *ucb, int dsize) 1401 { 1402 if (!uprobe_perf_filter(&tu->consumer, 0, current->mm)) 1403 return UPROBE_HANDLER_REMOVE; 1404 1405 if (!is_ret_probe(tu)) 1406 __uprobe_perf_func(tu, 0, regs, ucb, dsize); 1407 return 0; 1408 } 1409 1410 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func, 1411 struct pt_regs *regs, 1412 struct uprobe_cpu_buffer *ucb, int dsize) 1413 { 1414 __uprobe_perf_func(tu, func, regs, ucb, dsize); 1415 } 1416 1417 int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type, 1418 const char **filename, u64 *probe_offset, 1419 bool perf_type_tracepoint) 1420 { 1421 const char *pevent = trace_event_name(event->tp_event); 1422 const char *group = event->tp_event->class->system; 1423 struct trace_uprobe *tu; 1424 1425 if (perf_type_tracepoint) 1426 tu = find_probe_event(pevent, group); 1427 else 1428 tu = trace_uprobe_primary_from_call(event->tp_event); 1429 if (!tu) 1430 return -EINVAL; 1431 1432 *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE 1433 : BPF_FD_TYPE_UPROBE; 1434 *filename = tu->filename; 1435 *probe_offset = tu->offset; 1436 return 0; 1437 } 1438 #endif /* CONFIG_PERF_EVENTS */ 1439 1440 static int 1441 trace_uprobe_register(struct trace_event_call *event, enum trace_reg type, 1442 void *data) 1443 { 1444 struct trace_event_file *file = data; 1445 1446 switch (type) { 1447 case TRACE_REG_REGISTER: 1448 return probe_event_enable(event, file, NULL); 1449 1450 case TRACE_REG_UNREGISTER: 1451 probe_event_disable(event, file); 1452 return 0; 1453 1454 #ifdef CONFIG_PERF_EVENTS 1455 case TRACE_REG_PERF_REGISTER: 1456 return probe_event_enable(event, NULL, uprobe_perf_filter); 1457 1458 case TRACE_REG_PERF_UNREGISTER: 1459 probe_event_disable(event, NULL); 1460 return 0; 1461 1462 case TRACE_REG_PERF_OPEN: 1463 return uprobe_perf_open(event, data); 1464 1465 case TRACE_REG_PERF_CLOSE: 1466 return uprobe_perf_close(event, data); 1467 1468 #endif 1469 default: 1470 return 0; 1471 } 1472 } 1473 1474 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) 1475 { 1476 struct trace_uprobe *tu; 1477 struct uprobe_dispatch_data udd; 1478 struct uprobe_cpu_buffer *ucb; 1479 int dsize, esize; 1480 int ret = 0; 1481 1482 1483 tu = container_of(con, struct trace_uprobe, consumer); 1484 tu->nhit++; 1485 1486 udd.tu = tu; 1487 udd.bp_addr = instruction_pointer(regs); 1488 1489 current->utask->vaddr = (unsigned long) &udd; 1490 1491 if (WARN_ON_ONCE(!uprobe_cpu_buffer)) 1492 return 0; 1493 1494 dsize = __get_data_size(&tu->tp, regs); 1495 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1496 1497 ucb = uprobe_buffer_get(); 1498 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize); 1499 1500 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) 1501 ret |= uprobe_trace_func(tu, regs, ucb, dsize); 1502 1503 #ifdef CONFIG_PERF_EVENTS 1504 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) 1505 ret |= uprobe_perf_func(tu, regs, ucb, dsize); 1506 #endif 1507 uprobe_buffer_put(ucb); 1508 return ret; 1509 } 1510 1511 static int uretprobe_dispatcher(struct uprobe_consumer *con, 1512 unsigned long func, struct pt_regs *regs) 1513 { 1514 struct trace_uprobe *tu; 1515 struct uprobe_dispatch_data udd; 1516 struct uprobe_cpu_buffer *ucb; 1517 int dsize, esize; 1518 1519 tu = container_of(con, struct trace_uprobe, consumer); 1520 1521 udd.tu = tu; 1522 udd.bp_addr = func; 1523 1524 current->utask->vaddr = (unsigned long) &udd; 1525 1526 if (WARN_ON_ONCE(!uprobe_cpu_buffer)) 1527 return 0; 1528 1529 dsize = __get_data_size(&tu->tp, regs); 1530 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1531 1532 ucb = uprobe_buffer_get(); 1533 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize); 1534 1535 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) 1536 uretprobe_trace_func(tu, func, regs, ucb, dsize); 1537 1538 #ifdef CONFIG_PERF_EVENTS 1539 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) 1540 uretprobe_perf_func(tu, func, regs, ucb, dsize); 1541 #endif 1542 uprobe_buffer_put(ucb); 1543 return 0; 1544 } 1545 1546 static struct trace_event_functions uprobe_funcs = { 1547 .trace = print_uprobe_event 1548 }; 1549 1550 static struct trace_event_fields uprobe_fields_array[] = { 1551 { .type = TRACE_FUNCTION_TYPE, 1552 .define_fields = uprobe_event_define_fields }, 1553 {} 1554 }; 1555 1556 static inline void init_trace_event_call(struct trace_uprobe *tu) 1557 { 1558 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 1559 call->event.funcs = &uprobe_funcs; 1560 call->class->fields_array = uprobe_fields_array; 1561 1562 call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY; 1563 call->class->reg = trace_uprobe_register; 1564 } 1565 1566 static int register_uprobe_event(struct trace_uprobe *tu) 1567 { 1568 init_trace_event_call(tu); 1569 1570 return trace_probe_register_event_call(&tu->tp); 1571 } 1572 1573 static int unregister_uprobe_event(struct trace_uprobe *tu) 1574 { 1575 return trace_probe_unregister_event_call(&tu->tp); 1576 } 1577 1578 #ifdef CONFIG_PERF_EVENTS 1579 struct trace_event_call * 1580 create_local_trace_uprobe(char *name, unsigned long offs, 1581 unsigned long ref_ctr_offset, bool is_return) 1582 { 1583 enum probe_print_type ptype; 1584 struct trace_uprobe *tu; 1585 struct path path; 1586 int ret; 1587 1588 ret = kern_path(name, LOOKUP_FOLLOW, &path); 1589 if (ret) 1590 return ERR_PTR(ret); 1591 1592 if (!d_is_reg(path.dentry)) { 1593 path_put(&path); 1594 return ERR_PTR(-EINVAL); 1595 } 1596 1597 /* 1598 * local trace_kprobes are not added to dyn_event, so they are never 1599 * searched in find_trace_kprobe(). Therefore, there is no concern of 1600 * duplicated name "DUMMY_EVENT" here. 1601 */ 1602 tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0, 1603 is_return); 1604 1605 if (IS_ERR(tu)) { 1606 pr_info("Failed to allocate trace_uprobe.(%d)\n", 1607 (int)PTR_ERR(tu)); 1608 path_put(&path); 1609 return ERR_CAST(tu); 1610 } 1611 1612 tu->offset = offs; 1613 tu->path = path; 1614 tu->ref_ctr_offset = ref_ctr_offset; 1615 tu->filename = kstrdup(name, GFP_KERNEL); 1616 if (!tu->filename) { 1617 ret = -ENOMEM; 1618 goto error; 1619 } 1620 1621 init_trace_event_call(tu); 1622 1623 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; 1624 if (traceprobe_set_print_fmt(&tu->tp, ptype) < 0) { 1625 ret = -ENOMEM; 1626 goto error; 1627 } 1628 1629 return trace_probe_event_call(&tu->tp); 1630 error: 1631 free_trace_uprobe(tu); 1632 return ERR_PTR(ret); 1633 } 1634 1635 void destroy_local_trace_uprobe(struct trace_event_call *event_call) 1636 { 1637 struct trace_uprobe *tu; 1638 1639 tu = trace_uprobe_primary_from_call(event_call); 1640 1641 free_trace_uprobe(tu); 1642 } 1643 #endif /* CONFIG_PERF_EVENTS */ 1644 1645 /* Make a trace interface for controlling probe points */ 1646 static __init int init_uprobe_trace(void) 1647 { 1648 int ret; 1649 1650 ret = dyn_event_register(&trace_uprobe_ops); 1651 if (ret) 1652 return ret; 1653 1654 ret = tracing_init_dentry(); 1655 if (ret) 1656 return 0; 1657 1658 trace_create_file("uprobe_events", TRACE_MODE_WRITE, NULL, 1659 NULL, &uprobe_events_ops); 1660 /* Profile interface */ 1661 trace_create_file("uprobe_profile", TRACE_MODE_READ, NULL, 1662 NULL, &uprobe_profile_ops); 1663 return 0; 1664 } 1665 1666 fs_initcall(init_uprobe_trace); 1667