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 int ret; 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_COMM: 240 val = FETCH_TOKEN_COMM; 241 break; 242 case FETCH_OP_FOFFS: 243 val = translate_user_vaddr(code->immediate); 244 break; 245 default: 246 ret = process_common_fetch_insn(code, &val); 247 if (ret < 0) 248 return ret; 249 } 250 code++; 251 252 return process_fetch_insn_bottom(code, val, dest, base); 253 } 254 NOKPROBE_SYMBOL(process_fetch_insn) 255 256 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter) 257 { 258 rwlock_init(&filter->rwlock); 259 filter->nr_systemwide = 0; 260 INIT_LIST_HEAD(&filter->perf_events); 261 } 262 263 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter) 264 { 265 return !filter->nr_systemwide && list_empty(&filter->perf_events); 266 } 267 268 static inline bool is_ret_probe(struct trace_uprobe *tu) 269 { 270 return tu->consumer.ret_handler != NULL; 271 } 272 273 static bool trace_uprobe_is_busy(struct dyn_event *ev) 274 { 275 struct trace_uprobe *tu = to_trace_uprobe(ev); 276 277 return trace_probe_is_enabled(&tu->tp); 278 } 279 280 static bool trace_uprobe_match_command_head(struct trace_uprobe *tu, 281 int argc, const char **argv) 282 { 283 char buf[MAX_ARGSTR_LEN + 1]; 284 int len; 285 286 if (!argc) 287 return true; 288 289 len = strlen(tu->filename); 290 if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':') 291 return false; 292 293 if (tu->ref_ctr_offset == 0) 294 snprintf(buf, sizeof(buf), "0x%0*lx", 295 (int)(sizeof(void *) * 2), tu->offset); 296 else 297 snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)", 298 (int)(sizeof(void *) * 2), tu->offset, 299 tu->ref_ctr_offset); 300 if (strcmp(buf, &argv[0][len + 1])) 301 return false; 302 303 argc--; argv++; 304 305 return trace_probe_match_command_args(&tu->tp, argc, argv); 306 } 307 308 static bool trace_uprobe_match(const char *system, const char *event, 309 int argc, const char **argv, struct dyn_event *ev) 310 { 311 struct trace_uprobe *tu = to_trace_uprobe(ev); 312 313 return (event[0] == '\0' || 314 strcmp(trace_probe_name(&tu->tp), event) == 0) && 315 (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) && 316 trace_uprobe_match_command_head(tu, argc, argv); 317 } 318 319 static nokprobe_inline struct trace_uprobe * 320 trace_uprobe_primary_from_call(struct trace_event_call *call) 321 { 322 struct trace_probe *tp; 323 324 tp = trace_probe_primary_from_call(call); 325 if (WARN_ON_ONCE(!tp)) 326 return NULL; 327 328 return container_of(tp, struct trace_uprobe, tp); 329 } 330 331 /* 332 * Allocate new trace_uprobe and initialize it (including uprobes). 333 */ 334 static struct trace_uprobe * 335 alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret) 336 { 337 struct trace_uprobe *tu; 338 int ret; 339 340 tu = kzalloc(struct_size(tu, tp.args, nargs), GFP_KERNEL); 341 if (!tu) 342 return ERR_PTR(-ENOMEM); 343 344 ret = trace_probe_init(&tu->tp, event, group, true); 345 if (ret < 0) 346 goto error; 347 348 dyn_event_init(&tu->devent, &trace_uprobe_ops); 349 tu->consumer.handler = uprobe_dispatcher; 350 if (is_ret) 351 tu->consumer.ret_handler = uretprobe_dispatcher; 352 init_trace_uprobe_filter(tu->tp.event->filter); 353 return tu; 354 355 error: 356 kfree(tu); 357 358 return ERR_PTR(ret); 359 } 360 361 static void free_trace_uprobe(struct trace_uprobe *tu) 362 { 363 if (!tu) 364 return; 365 366 path_put(&tu->path); 367 trace_probe_cleanup(&tu->tp); 368 kfree(tu->filename); 369 kfree(tu); 370 } 371 372 static struct trace_uprobe *find_probe_event(const char *event, const char *group) 373 { 374 struct dyn_event *pos; 375 struct trace_uprobe *tu; 376 377 for_each_trace_uprobe(tu, pos) 378 if (strcmp(trace_probe_name(&tu->tp), event) == 0 && 379 strcmp(trace_probe_group_name(&tu->tp), group) == 0) 380 return tu; 381 382 return NULL; 383 } 384 385 /* Unregister a trace_uprobe and probe_event */ 386 static int unregister_trace_uprobe(struct trace_uprobe *tu) 387 { 388 int ret; 389 390 if (trace_probe_has_sibling(&tu->tp)) 391 goto unreg; 392 393 /* If there's a reference to the dynamic event */ 394 if (trace_event_dyn_busy(trace_probe_event_call(&tu->tp))) 395 return -EBUSY; 396 397 ret = unregister_uprobe_event(tu); 398 if (ret) 399 return ret; 400 401 unreg: 402 dyn_event_remove(&tu->devent); 403 trace_probe_unlink(&tu->tp); 404 free_trace_uprobe(tu); 405 return 0; 406 } 407 408 static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig, 409 struct trace_uprobe *comp) 410 { 411 struct trace_probe_event *tpe = orig->tp.event; 412 struct inode *comp_inode = d_real_inode(comp->path.dentry); 413 int i; 414 415 list_for_each_entry(orig, &tpe->probes, tp.list) { 416 if (comp_inode != d_real_inode(orig->path.dentry) || 417 comp->offset != orig->offset) 418 continue; 419 420 /* 421 * trace_probe_compare_arg_type() ensured that nr_args and 422 * each argument name and type are same. Let's compare comm. 423 */ 424 for (i = 0; i < orig->tp.nr_args; i++) { 425 if (strcmp(orig->tp.args[i].comm, 426 comp->tp.args[i].comm)) 427 break; 428 } 429 430 if (i == orig->tp.nr_args) 431 return true; 432 } 433 434 return false; 435 } 436 437 static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to) 438 { 439 int ret; 440 441 ret = trace_probe_compare_arg_type(&tu->tp, &to->tp); 442 if (ret) { 443 /* Note that argument starts index = 2 */ 444 trace_probe_log_set_index(ret + 1); 445 trace_probe_log_err(0, DIFF_ARG_TYPE); 446 return -EEXIST; 447 } 448 if (trace_uprobe_has_same_uprobe(to, tu)) { 449 trace_probe_log_set_index(0); 450 trace_probe_log_err(0, SAME_PROBE); 451 return -EEXIST; 452 } 453 454 /* Append to existing event */ 455 ret = trace_probe_append(&tu->tp, &to->tp); 456 if (!ret) 457 dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp)); 458 459 return ret; 460 } 461 462 /* 463 * Uprobe with multiple reference counter is not allowed. i.e. 464 * If inode and offset matches, reference counter offset *must* 465 * match as well. Though, there is one exception: If user is 466 * replacing old trace_uprobe with new one(same group/event), 467 * then we allow same uprobe with new reference counter as far 468 * as the new one does not conflict with any other existing 469 * ones. 470 */ 471 static int validate_ref_ctr_offset(struct trace_uprobe *new) 472 { 473 struct dyn_event *pos; 474 struct trace_uprobe *tmp; 475 struct inode *new_inode = d_real_inode(new->path.dentry); 476 477 for_each_trace_uprobe(tmp, pos) { 478 if (new_inode == d_real_inode(tmp->path.dentry) && 479 new->offset == tmp->offset && 480 new->ref_ctr_offset != tmp->ref_ctr_offset) { 481 pr_warn("Reference counter offset mismatch."); 482 return -EINVAL; 483 } 484 } 485 return 0; 486 } 487 488 /* Register a trace_uprobe and probe_event */ 489 static int register_trace_uprobe(struct trace_uprobe *tu) 490 { 491 struct trace_uprobe *old_tu; 492 int ret; 493 494 mutex_lock(&event_mutex); 495 496 ret = validate_ref_ctr_offset(tu); 497 if (ret) 498 goto end; 499 500 /* register as an event */ 501 old_tu = find_probe_event(trace_probe_name(&tu->tp), 502 trace_probe_group_name(&tu->tp)); 503 if (old_tu) { 504 if (is_ret_probe(tu) != is_ret_probe(old_tu)) { 505 trace_probe_log_set_index(0); 506 trace_probe_log_err(0, DIFF_PROBE_TYPE); 507 ret = -EEXIST; 508 } else { 509 ret = append_trace_uprobe(tu, old_tu); 510 } 511 goto end; 512 } 513 514 ret = register_uprobe_event(tu); 515 if (ret) { 516 if (ret == -EEXIST) { 517 trace_probe_log_set_index(0); 518 trace_probe_log_err(0, EVENT_EXIST); 519 } else 520 pr_warn("Failed to register probe event(%d)\n", ret); 521 goto end; 522 } 523 524 dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp)); 525 526 end: 527 mutex_unlock(&event_mutex); 528 529 return ret; 530 } 531 532 /* 533 * Argument syntax: 534 * - Add uprobe: p|r[:[GRP/][EVENT]] PATH:OFFSET[%return][(REF)] [FETCHARGS] 535 */ 536 static int __trace_uprobe_create(int argc, const char **argv) 537 { 538 struct trace_uprobe *tu; 539 const char *event = NULL, *group = UPROBE_EVENT_SYSTEM; 540 char *arg, *filename, *rctr, *rctr_end, *tmp; 541 char buf[MAX_EVENT_NAME_LEN]; 542 char gbuf[MAX_EVENT_NAME_LEN]; 543 enum probe_print_type ptype; 544 struct path path; 545 unsigned long offset, ref_ctr_offset; 546 bool is_return = false; 547 int i, ret; 548 549 ref_ctr_offset = 0; 550 551 switch (argv[0][0]) { 552 case 'r': 553 is_return = true; 554 break; 555 case 'p': 556 break; 557 default: 558 return -ECANCELED; 559 } 560 561 if (argc < 2) 562 return -ECANCELED; 563 564 if (argv[0][1] == ':') 565 event = &argv[0][2]; 566 567 if (!strchr(argv[1], '/')) 568 return -ECANCELED; 569 570 filename = kstrdup(argv[1], GFP_KERNEL); 571 if (!filename) 572 return -ENOMEM; 573 574 /* Find the last occurrence, in case the path contains ':' too. */ 575 arg = strrchr(filename, ':'); 576 if (!arg || !isdigit(arg[1])) { 577 kfree(filename); 578 return -ECANCELED; 579 } 580 581 trace_probe_log_init("trace_uprobe", argc, argv); 582 trace_probe_log_set_index(1); /* filename is the 2nd argument */ 583 584 *arg++ = '\0'; 585 ret = kern_path(filename, LOOKUP_FOLLOW, &path); 586 if (ret) { 587 trace_probe_log_err(0, FILE_NOT_FOUND); 588 kfree(filename); 589 trace_probe_log_clear(); 590 return ret; 591 } 592 if (!d_is_reg(path.dentry)) { 593 trace_probe_log_err(0, NO_REGULAR_FILE); 594 ret = -EINVAL; 595 goto fail_address_parse; 596 } 597 598 /* Parse reference counter offset if specified. */ 599 rctr = strchr(arg, '('); 600 if (rctr) { 601 rctr_end = strchr(rctr, ')'); 602 if (!rctr_end) { 603 ret = -EINVAL; 604 rctr_end = rctr + strlen(rctr); 605 trace_probe_log_err(rctr_end - filename, 606 REFCNT_OPEN_BRACE); 607 goto fail_address_parse; 608 } else if (rctr_end[1] != '\0') { 609 ret = -EINVAL; 610 trace_probe_log_err(rctr_end + 1 - filename, 611 BAD_REFCNT_SUFFIX); 612 goto fail_address_parse; 613 } 614 615 *rctr++ = '\0'; 616 *rctr_end = '\0'; 617 ret = kstrtoul(rctr, 0, &ref_ctr_offset); 618 if (ret) { 619 trace_probe_log_err(rctr - filename, BAD_REFCNT); 620 goto fail_address_parse; 621 } 622 } 623 624 /* Check if there is %return suffix */ 625 tmp = strchr(arg, '%'); 626 if (tmp) { 627 if (!strcmp(tmp, "%return")) { 628 *tmp = '\0'; 629 is_return = true; 630 } else { 631 trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX); 632 ret = -EINVAL; 633 goto fail_address_parse; 634 } 635 } 636 637 /* Parse uprobe offset. */ 638 ret = kstrtoul(arg, 0, &offset); 639 if (ret) { 640 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS); 641 goto fail_address_parse; 642 } 643 644 /* setup a probe */ 645 trace_probe_log_set_index(0); 646 if (event) { 647 ret = traceprobe_parse_event_name(&event, &group, gbuf, 648 event - argv[0]); 649 if (ret) 650 goto fail_address_parse; 651 } 652 653 if (!event) { 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 TPARG_FL_USER); 693 if (ret) 694 goto error; 695 } 696 697 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; 698 ret = traceprobe_set_print_fmt(&tu->tp, ptype); 699 if (ret < 0) 700 goto error; 701 702 ret = register_trace_uprobe(tu); 703 if (!ret) 704 goto out; 705 706 error: 707 free_trace_uprobe(tu); 708 out: 709 trace_probe_log_clear(); 710 return ret; 711 712 fail_address_parse: 713 trace_probe_log_clear(); 714 path_put(&path); 715 kfree(filename); 716 717 return ret; 718 } 719 720 int trace_uprobe_create(const char *raw_command) 721 { 722 return trace_probe_create(raw_command, __trace_uprobe_create); 723 } 724 725 static int create_or_delete_trace_uprobe(const char *raw_command) 726 { 727 int ret; 728 729 if (raw_command[0] == '-') 730 return dyn_event_release(raw_command, &trace_uprobe_ops); 731 732 ret = trace_uprobe_create(raw_command); 733 return ret == -ECANCELED ? -EINVAL : ret; 734 } 735 736 static int trace_uprobe_release(struct dyn_event *ev) 737 { 738 struct trace_uprobe *tu = to_trace_uprobe(ev); 739 740 return unregister_trace_uprobe(tu); 741 } 742 743 /* Probes listing interfaces */ 744 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev) 745 { 746 struct trace_uprobe *tu = to_trace_uprobe(ev); 747 char c = is_ret_probe(tu) ? 'r' : 'p'; 748 int i; 749 750 seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp), 751 trace_probe_name(&tu->tp), tu->filename, 752 (int)(sizeof(void *) * 2), tu->offset); 753 754 if (tu->ref_ctr_offset) 755 seq_printf(m, "(0x%lx)", tu->ref_ctr_offset); 756 757 for (i = 0; i < tu->tp.nr_args; i++) 758 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm); 759 760 seq_putc(m, '\n'); 761 return 0; 762 } 763 764 static int probes_seq_show(struct seq_file *m, void *v) 765 { 766 struct dyn_event *ev = v; 767 768 if (!is_trace_uprobe(ev)) 769 return 0; 770 771 return trace_uprobe_show(m, ev); 772 } 773 774 static const struct seq_operations probes_seq_op = { 775 .start = dyn_event_seq_start, 776 .next = dyn_event_seq_next, 777 .stop = dyn_event_seq_stop, 778 .show = probes_seq_show 779 }; 780 781 static int probes_open(struct inode *inode, struct file *file) 782 { 783 int ret; 784 785 ret = security_locked_down(LOCKDOWN_TRACEFS); 786 if (ret) 787 return ret; 788 789 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { 790 ret = dyn_events_release_all(&trace_uprobe_ops); 791 if (ret) 792 return ret; 793 } 794 795 return seq_open(file, &probes_seq_op); 796 } 797 798 static ssize_t probes_write(struct file *file, const char __user *buffer, 799 size_t count, loff_t *ppos) 800 { 801 return trace_parse_run_command(file, buffer, count, ppos, 802 create_or_delete_trace_uprobe); 803 } 804 805 static const struct file_operations uprobe_events_ops = { 806 .owner = THIS_MODULE, 807 .open = probes_open, 808 .read = seq_read, 809 .llseek = seq_lseek, 810 .release = seq_release, 811 .write = probes_write, 812 }; 813 814 /* Probes profiling interfaces */ 815 static int probes_profile_seq_show(struct seq_file *m, void *v) 816 { 817 struct dyn_event *ev = v; 818 struct trace_uprobe *tu; 819 820 if (!is_trace_uprobe(ev)) 821 return 0; 822 823 tu = to_trace_uprobe(ev); 824 seq_printf(m, " %s %-44s %15lu\n", tu->filename, 825 trace_probe_name(&tu->tp), tu->nhit); 826 return 0; 827 } 828 829 static const struct seq_operations profile_seq_op = { 830 .start = dyn_event_seq_start, 831 .next = dyn_event_seq_next, 832 .stop = dyn_event_seq_stop, 833 .show = probes_profile_seq_show 834 }; 835 836 static int profile_open(struct inode *inode, struct file *file) 837 { 838 int ret; 839 840 ret = security_locked_down(LOCKDOWN_TRACEFS); 841 if (ret) 842 return ret; 843 844 return seq_open(file, &profile_seq_op); 845 } 846 847 static const struct file_operations uprobe_profile_ops = { 848 .owner = THIS_MODULE, 849 .open = profile_open, 850 .read = seq_read, 851 .llseek = seq_lseek, 852 .release = seq_release, 853 }; 854 855 struct uprobe_cpu_buffer { 856 struct mutex mutex; 857 void *buf; 858 }; 859 static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer; 860 static int uprobe_buffer_refcnt; 861 862 static int uprobe_buffer_init(void) 863 { 864 int cpu, err_cpu; 865 866 uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer); 867 if (uprobe_cpu_buffer == NULL) 868 return -ENOMEM; 869 870 for_each_possible_cpu(cpu) { 871 struct page *p = alloc_pages_node(cpu_to_node(cpu), 872 GFP_KERNEL, 0); 873 if (p == NULL) { 874 err_cpu = cpu; 875 goto err; 876 } 877 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p); 878 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex); 879 } 880 881 return 0; 882 883 err: 884 for_each_possible_cpu(cpu) { 885 if (cpu == err_cpu) 886 break; 887 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf); 888 } 889 890 free_percpu(uprobe_cpu_buffer); 891 return -ENOMEM; 892 } 893 894 static int uprobe_buffer_enable(void) 895 { 896 int ret = 0; 897 898 BUG_ON(!mutex_is_locked(&event_mutex)); 899 900 if (uprobe_buffer_refcnt++ == 0) { 901 ret = uprobe_buffer_init(); 902 if (ret < 0) 903 uprobe_buffer_refcnt--; 904 } 905 906 return ret; 907 } 908 909 static void uprobe_buffer_disable(void) 910 { 911 int cpu; 912 913 BUG_ON(!mutex_is_locked(&event_mutex)); 914 915 if (--uprobe_buffer_refcnt == 0) { 916 for_each_possible_cpu(cpu) 917 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, 918 cpu)->buf); 919 920 free_percpu(uprobe_cpu_buffer); 921 uprobe_cpu_buffer = NULL; 922 } 923 } 924 925 static struct uprobe_cpu_buffer *uprobe_buffer_get(void) 926 { 927 struct uprobe_cpu_buffer *ucb; 928 int cpu; 929 930 cpu = raw_smp_processor_id(); 931 ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu); 932 933 /* 934 * Use per-cpu buffers for fastest access, but we might migrate 935 * so the mutex makes sure we have sole access to it. 936 */ 937 mutex_lock(&ucb->mutex); 938 939 return ucb; 940 } 941 942 static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb) 943 { 944 mutex_unlock(&ucb->mutex); 945 } 946 947 static void __uprobe_trace_func(struct trace_uprobe *tu, 948 unsigned long func, struct pt_regs *regs, 949 struct uprobe_cpu_buffer *ucb, int dsize, 950 struct trace_event_file *trace_file) 951 { 952 struct uprobe_trace_entry_head *entry; 953 struct trace_event_buffer fbuffer; 954 void *data; 955 int size, esize; 956 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 957 958 WARN_ON(call != trace_file->event_call); 959 960 if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE)) 961 return; 962 963 if (trace_trigger_soft_disabled(trace_file)) 964 return; 965 966 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 967 size = esize + tu->tp.size + dsize; 968 entry = trace_event_buffer_reserve(&fbuffer, trace_file, size); 969 if (!entry) 970 return; 971 972 if (is_ret_probe(tu)) { 973 entry->vaddr[0] = func; 974 entry->vaddr[1] = instruction_pointer(regs); 975 data = DATAOF_TRACE_ENTRY(entry, true); 976 } else { 977 entry->vaddr[0] = instruction_pointer(regs); 978 data = DATAOF_TRACE_ENTRY(entry, false); 979 } 980 981 memcpy(data, ucb->buf, tu->tp.size + dsize); 982 983 trace_event_buffer_commit(&fbuffer); 984 } 985 986 /* uprobe handler */ 987 static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs, 988 struct uprobe_cpu_buffer *ucb, int dsize) 989 { 990 struct event_file_link *link; 991 992 if (is_ret_probe(tu)) 993 return 0; 994 995 rcu_read_lock(); 996 trace_probe_for_each_link_rcu(link, &tu->tp) 997 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file); 998 rcu_read_unlock(); 999 1000 return 0; 1001 } 1002 1003 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func, 1004 struct pt_regs *regs, 1005 struct uprobe_cpu_buffer *ucb, int dsize) 1006 { 1007 struct event_file_link *link; 1008 1009 rcu_read_lock(); 1010 trace_probe_for_each_link_rcu(link, &tu->tp) 1011 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file); 1012 rcu_read_unlock(); 1013 } 1014 1015 /* Event entry printers */ 1016 static enum print_line_t 1017 print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) 1018 { 1019 struct uprobe_trace_entry_head *entry; 1020 struct trace_seq *s = &iter->seq; 1021 struct trace_uprobe *tu; 1022 u8 *data; 1023 1024 entry = (struct uprobe_trace_entry_head *)iter->ent; 1025 tu = trace_uprobe_primary_from_call( 1026 container_of(event, struct trace_event_call, event)); 1027 if (unlikely(!tu)) 1028 goto out; 1029 1030 if (is_ret_probe(tu)) { 1031 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)", 1032 trace_probe_name(&tu->tp), 1033 entry->vaddr[1], entry->vaddr[0]); 1034 data = DATAOF_TRACE_ENTRY(entry, true); 1035 } else { 1036 trace_seq_printf(s, "%s: (0x%lx)", 1037 trace_probe_name(&tu->tp), 1038 entry->vaddr[0]); 1039 data = DATAOF_TRACE_ENTRY(entry, false); 1040 } 1041 1042 if (trace_probe_print_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0) 1043 goto out; 1044 1045 trace_seq_putc(s, '\n'); 1046 1047 out: 1048 return trace_handle_return(s); 1049 } 1050 1051 typedef bool (*filter_func_t)(struct uprobe_consumer *self, 1052 enum uprobe_filter_ctx ctx, 1053 struct mm_struct *mm); 1054 1055 static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter) 1056 { 1057 int ret; 1058 1059 tu->consumer.filter = filter; 1060 tu->inode = d_real_inode(tu->path.dentry); 1061 1062 if (tu->ref_ctr_offset) 1063 ret = uprobe_register_refctr(tu->inode, tu->offset, 1064 tu->ref_ctr_offset, &tu->consumer); 1065 else 1066 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer); 1067 1068 if (ret) 1069 tu->inode = NULL; 1070 1071 return ret; 1072 } 1073 1074 static void __probe_event_disable(struct trace_probe *tp) 1075 { 1076 struct trace_uprobe *tu; 1077 1078 tu = container_of(tp, struct trace_uprobe, tp); 1079 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter)); 1080 1081 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1082 if (!tu->inode) 1083 continue; 1084 1085 uprobe_unregister(tu->inode, tu->offset, &tu->consumer); 1086 tu->inode = NULL; 1087 } 1088 } 1089 1090 static int probe_event_enable(struct trace_event_call *call, 1091 struct trace_event_file *file, filter_func_t filter) 1092 { 1093 struct trace_probe *tp; 1094 struct trace_uprobe *tu; 1095 bool enabled; 1096 int ret; 1097 1098 tp = trace_probe_primary_from_call(call); 1099 if (WARN_ON_ONCE(!tp)) 1100 return -ENODEV; 1101 enabled = trace_probe_is_enabled(tp); 1102 1103 /* This may also change "enabled" state */ 1104 if (file) { 1105 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE)) 1106 return -EINTR; 1107 1108 ret = trace_probe_add_file(tp, file); 1109 if (ret < 0) 1110 return ret; 1111 } else { 1112 if (trace_probe_test_flag(tp, TP_FLAG_TRACE)) 1113 return -EINTR; 1114 1115 trace_probe_set_flag(tp, TP_FLAG_PROFILE); 1116 } 1117 1118 tu = container_of(tp, struct trace_uprobe, tp); 1119 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter)); 1120 1121 if (enabled) 1122 return 0; 1123 1124 ret = uprobe_buffer_enable(); 1125 if (ret) 1126 goto err_flags; 1127 1128 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1129 ret = trace_uprobe_enable(tu, filter); 1130 if (ret) { 1131 __probe_event_disable(tp); 1132 goto err_buffer; 1133 } 1134 } 1135 1136 return 0; 1137 1138 err_buffer: 1139 uprobe_buffer_disable(); 1140 1141 err_flags: 1142 if (file) 1143 trace_probe_remove_file(tp, file); 1144 else 1145 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 1146 1147 return ret; 1148 } 1149 1150 static void probe_event_disable(struct trace_event_call *call, 1151 struct trace_event_file *file) 1152 { 1153 struct trace_probe *tp; 1154 1155 tp = trace_probe_primary_from_call(call); 1156 if (WARN_ON_ONCE(!tp)) 1157 return; 1158 1159 if (!trace_probe_is_enabled(tp)) 1160 return; 1161 1162 if (file) { 1163 if (trace_probe_remove_file(tp, file) < 0) 1164 return; 1165 1166 if (trace_probe_is_enabled(tp)) 1167 return; 1168 } else 1169 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 1170 1171 __probe_event_disable(tp); 1172 uprobe_buffer_disable(); 1173 } 1174 1175 static int uprobe_event_define_fields(struct trace_event_call *event_call) 1176 { 1177 int ret, size; 1178 struct uprobe_trace_entry_head field; 1179 struct trace_uprobe *tu; 1180 1181 tu = trace_uprobe_primary_from_call(event_call); 1182 if (unlikely(!tu)) 1183 return -ENODEV; 1184 1185 if (is_ret_probe(tu)) { 1186 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0); 1187 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0); 1188 size = SIZEOF_TRACE_ENTRY(true); 1189 } else { 1190 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0); 1191 size = SIZEOF_TRACE_ENTRY(false); 1192 } 1193 1194 return traceprobe_define_arg_fields(event_call, size, &tu->tp); 1195 } 1196 1197 #ifdef CONFIG_PERF_EVENTS 1198 static bool 1199 __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm) 1200 { 1201 struct perf_event *event; 1202 1203 if (filter->nr_systemwide) 1204 return true; 1205 1206 list_for_each_entry(event, &filter->perf_events, hw.tp_list) { 1207 if (event->hw.target->mm == mm) 1208 return true; 1209 } 1210 1211 return false; 1212 } 1213 1214 static inline bool 1215 trace_uprobe_filter_event(struct trace_uprobe_filter *filter, 1216 struct perf_event *event) 1217 { 1218 return __uprobe_perf_filter(filter, event->hw.target->mm); 1219 } 1220 1221 static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter, 1222 struct perf_event *event) 1223 { 1224 bool done; 1225 1226 write_lock(&filter->rwlock); 1227 if (event->hw.target) { 1228 list_del(&event->hw.tp_list); 1229 done = filter->nr_systemwide || 1230 (event->hw.target->flags & PF_EXITING) || 1231 trace_uprobe_filter_event(filter, event); 1232 } else { 1233 filter->nr_systemwide--; 1234 done = filter->nr_systemwide; 1235 } 1236 write_unlock(&filter->rwlock); 1237 1238 return done; 1239 } 1240 1241 /* This returns true if the filter always covers target mm */ 1242 static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter, 1243 struct perf_event *event) 1244 { 1245 bool done; 1246 1247 write_lock(&filter->rwlock); 1248 if (event->hw.target) { 1249 /* 1250 * event->parent != NULL means copy_process(), we can avoid 1251 * uprobe_apply(). current->mm must be probed and we can rely 1252 * on dup_mmap() which preserves the already installed bp's. 1253 * 1254 * attr.enable_on_exec means that exec/mmap will install the 1255 * breakpoints we need. 1256 */ 1257 done = filter->nr_systemwide || 1258 event->parent || event->attr.enable_on_exec || 1259 trace_uprobe_filter_event(filter, event); 1260 list_add(&event->hw.tp_list, &filter->perf_events); 1261 } else { 1262 done = filter->nr_systemwide; 1263 filter->nr_systemwide++; 1264 } 1265 write_unlock(&filter->rwlock); 1266 1267 return done; 1268 } 1269 1270 static int uprobe_perf_close(struct trace_event_call *call, 1271 struct perf_event *event) 1272 { 1273 struct trace_probe *tp; 1274 struct trace_uprobe *tu; 1275 int ret = 0; 1276 1277 tp = trace_probe_primary_from_call(call); 1278 if (WARN_ON_ONCE(!tp)) 1279 return -ENODEV; 1280 1281 tu = container_of(tp, struct trace_uprobe, tp); 1282 if (trace_uprobe_filter_remove(tu->tp.event->filter, event)) 1283 return 0; 1284 1285 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1286 ret = uprobe_apply(tu->inode, tu->offset, &tu->consumer, false); 1287 if (ret) 1288 break; 1289 } 1290 1291 return ret; 1292 } 1293 1294 static int uprobe_perf_open(struct trace_event_call *call, 1295 struct perf_event *event) 1296 { 1297 struct trace_probe *tp; 1298 struct trace_uprobe *tu; 1299 int err = 0; 1300 1301 tp = trace_probe_primary_from_call(call); 1302 if (WARN_ON_ONCE(!tp)) 1303 return -ENODEV; 1304 1305 tu = container_of(tp, struct trace_uprobe, tp); 1306 if (trace_uprobe_filter_add(tu->tp.event->filter, event)) 1307 return 0; 1308 1309 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1310 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true); 1311 if (err) { 1312 uprobe_perf_close(call, event); 1313 break; 1314 } 1315 } 1316 1317 return err; 1318 } 1319 1320 static bool uprobe_perf_filter(struct uprobe_consumer *uc, 1321 enum uprobe_filter_ctx ctx, struct mm_struct *mm) 1322 { 1323 struct trace_uprobe_filter *filter; 1324 struct trace_uprobe *tu; 1325 int ret; 1326 1327 tu = container_of(uc, struct trace_uprobe, consumer); 1328 filter = tu->tp.event->filter; 1329 1330 read_lock(&filter->rwlock); 1331 ret = __uprobe_perf_filter(filter, mm); 1332 read_unlock(&filter->rwlock); 1333 1334 return ret; 1335 } 1336 1337 static void __uprobe_perf_func(struct trace_uprobe *tu, 1338 unsigned long func, struct pt_regs *regs, 1339 struct uprobe_cpu_buffer *ucb, int dsize) 1340 { 1341 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 1342 struct uprobe_trace_entry_head *entry; 1343 struct hlist_head *head; 1344 void *data; 1345 int size, esize; 1346 int rctx; 1347 1348 #ifdef CONFIG_BPF_EVENTS 1349 if (bpf_prog_array_valid(call)) { 1350 u32 ret; 1351 1352 ret = bpf_prog_run_array_sleepable(call->prog_array, regs, bpf_prog_run); 1353 if (!ret) 1354 return; 1355 } 1356 #endif /* CONFIG_BPF_EVENTS */ 1357 1358 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1359 1360 size = esize + tu->tp.size + dsize; 1361 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32); 1362 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) 1363 return; 1364 1365 preempt_disable(); 1366 head = this_cpu_ptr(call->perf_events); 1367 if (hlist_empty(head)) 1368 goto out; 1369 1370 entry = perf_trace_buf_alloc(size, NULL, &rctx); 1371 if (!entry) 1372 goto out; 1373 1374 if (is_ret_probe(tu)) { 1375 entry->vaddr[0] = func; 1376 entry->vaddr[1] = instruction_pointer(regs); 1377 data = DATAOF_TRACE_ENTRY(entry, true); 1378 } else { 1379 entry->vaddr[0] = instruction_pointer(regs); 1380 data = DATAOF_TRACE_ENTRY(entry, false); 1381 } 1382 1383 memcpy(data, ucb->buf, tu->tp.size + dsize); 1384 1385 if (size - esize > tu->tp.size + dsize) { 1386 int len = tu->tp.size + dsize; 1387 1388 memset(data + len, 0, size - esize - len); 1389 } 1390 1391 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, 1392 head, NULL); 1393 out: 1394 preempt_enable(); 1395 } 1396 1397 /* uprobe profile handler */ 1398 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs, 1399 struct uprobe_cpu_buffer *ucb, int dsize) 1400 { 1401 if (!uprobe_perf_filter(&tu->consumer, 0, current->mm)) 1402 return UPROBE_HANDLER_REMOVE; 1403 1404 if (!is_ret_probe(tu)) 1405 __uprobe_perf_func(tu, 0, regs, ucb, dsize); 1406 return 0; 1407 } 1408 1409 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func, 1410 struct pt_regs *regs, 1411 struct uprobe_cpu_buffer *ucb, int dsize) 1412 { 1413 __uprobe_perf_func(tu, func, regs, ucb, dsize); 1414 } 1415 1416 int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type, 1417 const char **filename, u64 *probe_offset, 1418 bool perf_type_tracepoint) 1419 { 1420 const char *pevent = trace_event_name(event->tp_event); 1421 const char *group = event->tp_event->class->system; 1422 struct trace_uprobe *tu; 1423 1424 if (perf_type_tracepoint) 1425 tu = find_probe_event(pevent, group); 1426 else 1427 tu = trace_uprobe_primary_from_call(event->tp_event); 1428 if (!tu) 1429 return -EINVAL; 1430 1431 *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE 1432 : BPF_FD_TYPE_UPROBE; 1433 *filename = tu->filename; 1434 *probe_offset = tu->offset; 1435 return 0; 1436 } 1437 #endif /* CONFIG_PERF_EVENTS */ 1438 1439 static int 1440 trace_uprobe_register(struct trace_event_call *event, enum trace_reg type, 1441 void *data) 1442 { 1443 struct trace_event_file *file = data; 1444 1445 switch (type) { 1446 case TRACE_REG_REGISTER: 1447 return probe_event_enable(event, file, NULL); 1448 1449 case TRACE_REG_UNREGISTER: 1450 probe_event_disable(event, file); 1451 return 0; 1452 1453 #ifdef CONFIG_PERF_EVENTS 1454 case TRACE_REG_PERF_REGISTER: 1455 return probe_event_enable(event, NULL, uprobe_perf_filter); 1456 1457 case TRACE_REG_PERF_UNREGISTER: 1458 probe_event_disable(event, NULL); 1459 return 0; 1460 1461 case TRACE_REG_PERF_OPEN: 1462 return uprobe_perf_open(event, data); 1463 1464 case TRACE_REG_PERF_CLOSE: 1465 return uprobe_perf_close(event, data); 1466 1467 #endif 1468 default: 1469 return 0; 1470 } 1471 } 1472 1473 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) 1474 { 1475 struct trace_uprobe *tu; 1476 struct uprobe_dispatch_data udd; 1477 struct uprobe_cpu_buffer *ucb; 1478 int dsize, esize; 1479 int ret = 0; 1480 1481 1482 tu = container_of(con, struct trace_uprobe, consumer); 1483 tu->nhit++; 1484 1485 udd.tu = tu; 1486 udd.bp_addr = instruction_pointer(regs); 1487 1488 current->utask->vaddr = (unsigned long) &udd; 1489 1490 if (WARN_ON_ONCE(!uprobe_cpu_buffer)) 1491 return 0; 1492 1493 dsize = __get_data_size(&tu->tp, regs); 1494 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1495 1496 ucb = uprobe_buffer_get(); 1497 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize); 1498 1499 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) 1500 ret |= uprobe_trace_func(tu, regs, ucb, dsize); 1501 1502 #ifdef CONFIG_PERF_EVENTS 1503 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) 1504 ret |= uprobe_perf_func(tu, regs, ucb, dsize); 1505 #endif 1506 uprobe_buffer_put(ucb); 1507 return ret; 1508 } 1509 1510 static int uretprobe_dispatcher(struct uprobe_consumer *con, 1511 unsigned long func, struct pt_regs *regs) 1512 { 1513 struct trace_uprobe *tu; 1514 struct uprobe_dispatch_data udd; 1515 struct uprobe_cpu_buffer *ucb; 1516 int dsize, esize; 1517 1518 tu = container_of(con, struct trace_uprobe, consumer); 1519 1520 udd.tu = tu; 1521 udd.bp_addr = func; 1522 1523 current->utask->vaddr = (unsigned long) &udd; 1524 1525 if (WARN_ON_ONCE(!uprobe_cpu_buffer)) 1526 return 0; 1527 1528 dsize = __get_data_size(&tu->tp, regs); 1529 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1530 1531 ucb = uprobe_buffer_get(); 1532 store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize); 1533 1534 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) 1535 uretprobe_trace_func(tu, func, regs, ucb, dsize); 1536 1537 #ifdef CONFIG_PERF_EVENTS 1538 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) 1539 uretprobe_perf_func(tu, func, regs, ucb, dsize); 1540 #endif 1541 uprobe_buffer_put(ucb); 1542 return 0; 1543 } 1544 1545 static struct trace_event_functions uprobe_funcs = { 1546 .trace = print_uprobe_event 1547 }; 1548 1549 static struct trace_event_fields uprobe_fields_array[] = { 1550 { .type = TRACE_FUNCTION_TYPE, 1551 .define_fields = uprobe_event_define_fields }, 1552 {} 1553 }; 1554 1555 static inline void init_trace_event_call(struct trace_uprobe *tu) 1556 { 1557 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 1558 call->event.funcs = &uprobe_funcs; 1559 call->class->fields_array = uprobe_fields_array; 1560 1561 call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY; 1562 call->class->reg = trace_uprobe_register; 1563 } 1564 1565 static int register_uprobe_event(struct trace_uprobe *tu) 1566 { 1567 init_trace_event_call(tu); 1568 1569 return trace_probe_register_event_call(&tu->tp); 1570 } 1571 1572 static int unregister_uprobe_event(struct trace_uprobe *tu) 1573 { 1574 return trace_probe_unregister_event_call(&tu->tp); 1575 } 1576 1577 #ifdef CONFIG_PERF_EVENTS 1578 struct trace_event_call * 1579 create_local_trace_uprobe(char *name, unsigned long offs, 1580 unsigned long ref_ctr_offset, bool is_return) 1581 { 1582 enum probe_print_type ptype; 1583 struct trace_uprobe *tu; 1584 struct path path; 1585 int ret; 1586 1587 ret = kern_path(name, LOOKUP_FOLLOW, &path); 1588 if (ret) 1589 return ERR_PTR(ret); 1590 1591 if (!d_is_reg(path.dentry)) { 1592 path_put(&path); 1593 return ERR_PTR(-EINVAL); 1594 } 1595 1596 /* 1597 * local trace_kprobes are not added to dyn_event, so they are never 1598 * searched in find_trace_kprobe(). Therefore, there is no concern of 1599 * duplicated name "DUMMY_EVENT" here. 1600 */ 1601 tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0, 1602 is_return); 1603 1604 if (IS_ERR(tu)) { 1605 pr_info("Failed to allocate trace_uprobe.(%d)\n", 1606 (int)PTR_ERR(tu)); 1607 path_put(&path); 1608 return ERR_CAST(tu); 1609 } 1610 1611 tu->offset = offs; 1612 tu->path = path; 1613 tu->ref_ctr_offset = ref_ctr_offset; 1614 tu->filename = kstrdup(name, GFP_KERNEL); 1615 if (!tu->filename) { 1616 ret = -ENOMEM; 1617 goto error; 1618 } 1619 1620 init_trace_event_call(tu); 1621 1622 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; 1623 if (traceprobe_set_print_fmt(&tu->tp, ptype) < 0) { 1624 ret = -ENOMEM; 1625 goto error; 1626 } 1627 1628 return trace_probe_event_call(&tu->tp); 1629 error: 1630 free_trace_uprobe(tu); 1631 return ERR_PTR(ret); 1632 } 1633 1634 void destroy_local_trace_uprobe(struct trace_event_call *event_call) 1635 { 1636 struct trace_uprobe *tu; 1637 1638 tu = trace_uprobe_primary_from_call(event_call); 1639 1640 free_trace_uprobe(tu); 1641 } 1642 #endif /* CONFIG_PERF_EVENTS */ 1643 1644 /* Make a trace interface for controlling probe points */ 1645 static __init int init_uprobe_trace(void) 1646 { 1647 int ret; 1648 1649 ret = dyn_event_register(&trace_uprobe_ops); 1650 if (ret) 1651 return ret; 1652 1653 ret = tracing_init_dentry(); 1654 if (ret) 1655 return 0; 1656 1657 trace_create_file("uprobe_events", TRACE_MODE_WRITE, NULL, 1658 NULL, &uprobe_events_ops); 1659 /* Profile interface */ 1660 trace_create_file("uprobe_profile", TRACE_MODE_READ, NULL, 1661 NULL, &uprobe_profile_ops); 1662 return 0; 1663 } 1664 1665 fs_initcall(init_uprobe_trace); 1666