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/cleanup.h> 12 #include <linux/ctype.h> 13 #include <linux/filter.h> 14 #include <linux/module.h> 15 #include <linux/namei.h> 16 #include <linux/percpu.h> 17 #include <linux/rculist.h> 18 #include <linux/security.h> 19 #include <linux/string.h> 20 #include <linux/uaccess.h> 21 #include <linux/uprobes.h> 22 23 #include "trace.h" 24 #include "trace_dynevent.h" 25 #include "trace_probe.h" 26 #include "trace_probe_tmpl.h" 27 28 #define UPROBE_EVENT_SYSTEM "uprobes" 29 30 struct uprobe_trace_entry_head { 31 struct trace_entry ent; 32 unsigned long vaddr[]; 33 }; 34 35 #define SIZEOF_TRACE_ENTRY(is_return) \ 36 (sizeof(struct uprobe_trace_entry_head) + \ 37 sizeof(unsigned long) * (is_return ? 2 : 1)) 38 39 #define DATAOF_TRACE_ENTRY(entry, is_return) \ 40 ((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return)) 41 42 static int trace_uprobe_create(const char *raw_command); 43 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev); 44 static int trace_uprobe_release(struct dyn_event *ev); 45 static bool trace_uprobe_is_busy(struct dyn_event *ev); 46 static bool trace_uprobe_match(const char *system, const char *event, 47 int argc, const char **argv, struct dyn_event *ev); 48 49 static struct dyn_event_operations trace_uprobe_ops = { 50 .create = trace_uprobe_create, 51 .show = trace_uprobe_show, 52 .is_busy = trace_uprobe_is_busy, 53 .free = trace_uprobe_release, 54 .match = trace_uprobe_match, 55 }; 56 57 /* 58 * uprobe event core functions 59 */ 60 struct trace_uprobe { 61 struct dyn_event devent; 62 struct uprobe_consumer consumer; 63 struct path path; 64 char *filename; 65 struct uprobe *uprobe; 66 unsigned long offset; 67 unsigned long ref_ctr_offset; 68 unsigned long __percpu *nhits; 69 struct trace_probe tp; 70 }; 71 72 static bool is_trace_uprobe(struct dyn_event *ev) 73 { 74 return ev->ops == &trace_uprobe_ops; 75 } 76 77 static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev) 78 { 79 return container_of(ev, struct trace_uprobe, devent); 80 } 81 82 /** 83 * for_each_trace_uprobe - iterate over the trace_uprobe list 84 * @pos: the struct trace_uprobe * for each entry 85 * @dpos: the struct dyn_event * to use as a loop cursor 86 */ 87 #define for_each_trace_uprobe(pos, dpos) \ 88 for_each_dyn_event(dpos) \ 89 if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos))) 90 91 static int register_uprobe_event(struct trace_uprobe *tu); 92 static int unregister_uprobe_event(struct trace_uprobe *tu); 93 94 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs, 95 __u64 *data); 96 static int uretprobe_dispatcher(struct uprobe_consumer *con, 97 unsigned long func, struct pt_regs *regs, 98 __u64 *data); 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 = strscpy(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 } else 174 *(u32 *)dest = make_data_loc(0, (void *)dst - base); 175 176 return ret; 177 } 178 179 static nokprobe_inline int 180 fetch_store_string_user(unsigned long addr, void *dest, void *base) 181 { 182 return fetch_store_string(addr, dest, base); 183 } 184 185 /* Return the length of string -- including null terminal byte */ 186 static nokprobe_inline int 187 fetch_store_strlen(unsigned long addr) 188 { 189 int len; 190 void __user *vaddr = (void __force __user *) addr; 191 192 if (addr == FETCH_TOKEN_COMM) 193 len = strlen(current->comm) + 1; 194 else 195 len = strnlen_user(vaddr, MAX_STRING_SIZE); 196 197 return (len > MAX_STRING_SIZE) ? 0 : len; 198 } 199 200 static nokprobe_inline int 201 fetch_store_strlen_user(unsigned long addr) 202 { 203 return fetch_store_strlen(addr); 204 } 205 206 static unsigned long translate_user_vaddr(unsigned long file_offset) 207 { 208 unsigned long base_addr; 209 struct uprobe_dispatch_data *udd; 210 211 udd = (void *) current->utask->vaddr; 212 213 base_addr = udd->bp_addr - udd->tu->offset; 214 return base_addr + file_offset; 215 } 216 217 /* Note that we don't verify it, since the code does not come from user space */ 218 static int 219 process_fetch_insn(struct fetch_insn *code, void *rec, void *edata, 220 void *dest, void *base) 221 { 222 struct pt_regs *regs = rec; 223 unsigned long val; 224 int ret; 225 226 /* 1st stage: get value from context */ 227 switch (code->op) { 228 case FETCH_OP_REG: 229 val = regs_get_register(regs, code->param); 230 break; 231 case FETCH_OP_STACK: 232 val = get_user_stack_nth(regs, code->param); 233 break; 234 case FETCH_OP_STACKP: 235 val = user_stack_pointer(regs); 236 break; 237 case FETCH_OP_RETVAL: 238 val = regs_return_value(regs); 239 break; 240 case FETCH_OP_COMM: 241 val = FETCH_TOKEN_COMM; 242 break; 243 case FETCH_OP_FOFFS: 244 val = translate_user_vaddr(code->immediate); 245 break; 246 default: 247 ret = process_common_fetch_insn(code, &val); 248 if (ret < 0) 249 return ret; 250 } 251 code++; 252 253 return process_fetch_insn_bottom(code, val, dest, base); 254 } 255 NOKPROBE_SYMBOL(process_fetch_insn) 256 257 static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter) 258 { 259 rwlock_init(&filter->rwlock); 260 filter->nr_systemwide = 0; 261 INIT_LIST_HEAD(&filter->perf_events); 262 } 263 264 static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter) 265 { 266 return !filter->nr_systemwide && list_empty(&filter->perf_events); 267 } 268 269 static inline bool is_ret_probe(struct trace_uprobe *tu) 270 { 271 return tu->consumer.ret_handler != NULL; 272 } 273 274 static bool trace_uprobe_is_busy(struct dyn_event *ev) 275 { 276 struct trace_uprobe *tu = to_trace_uprobe(ev); 277 278 return trace_probe_is_enabled(&tu->tp); 279 } 280 281 static bool trace_uprobe_match_command_head(struct trace_uprobe *tu, 282 int argc, const char **argv) 283 { 284 char buf[MAX_ARGSTR_LEN + 1]; 285 int len; 286 287 if (!argc) 288 return true; 289 290 len = strlen(tu->filename); 291 if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':') 292 return false; 293 294 if (tu->ref_ctr_offset == 0) 295 snprintf(buf, sizeof(buf), "0x%0*lx", 296 (int)(sizeof(void *) * 2), tu->offset); 297 else 298 snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)", 299 (int)(sizeof(void *) * 2), tu->offset, 300 tu->ref_ctr_offset); 301 if (strcmp(buf, &argv[0][len + 1])) 302 return false; 303 304 argc--; argv++; 305 306 return trace_probe_match_command_args(&tu->tp, argc, argv); 307 } 308 309 static bool trace_uprobe_match(const char *system, const char *event, 310 int argc, const char **argv, struct dyn_event *ev) 311 { 312 struct trace_uprobe *tu = to_trace_uprobe(ev); 313 314 return (event[0] == '\0' || 315 strcmp(trace_probe_name(&tu->tp), event) == 0) && 316 (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) && 317 trace_uprobe_match_command_head(tu, argc, argv); 318 } 319 320 static nokprobe_inline struct trace_uprobe * 321 trace_uprobe_primary_from_call(struct trace_event_call *call) 322 { 323 struct trace_probe *tp; 324 325 tp = trace_probe_primary_from_call(call); 326 if (WARN_ON_ONCE(!tp)) 327 return NULL; 328 329 return container_of(tp, struct trace_uprobe, tp); 330 } 331 332 /* 333 * Allocate new trace_uprobe and initialize it (including uprobes). 334 */ 335 static struct trace_uprobe * 336 alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret) 337 { 338 struct trace_uprobe *tu; 339 int ret; 340 341 tu = kzalloc(struct_size(tu, tp.args, nargs), GFP_KERNEL); 342 if (!tu) 343 return ERR_PTR(-ENOMEM); 344 345 tu->nhits = alloc_percpu(unsigned long); 346 if (!tu->nhits) { 347 ret = -ENOMEM; 348 goto error; 349 } 350 351 ret = trace_probe_init(&tu->tp, event, group, true, nargs); 352 if (ret < 0) 353 goto error; 354 355 dyn_event_init(&tu->devent, &trace_uprobe_ops); 356 tu->consumer.handler = uprobe_dispatcher; 357 if (is_ret) 358 tu->consumer.ret_handler = uretprobe_dispatcher; 359 init_trace_uprobe_filter(tu->tp.event->filter); 360 return tu; 361 362 error: 363 free_percpu(tu->nhits); 364 kfree(tu); 365 366 return ERR_PTR(ret); 367 } 368 369 static void free_trace_uprobe(struct trace_uprobe *tu) 370 { 371 if (!tu) 372 return; 373 374 path_put(&tu->path); 375 trace_probe_cleanup(&tu->tp); 376 kfree(tu->filename); 377 free_percpu(tu->nhits); 378 kfree(tu); 379 } 380 381 static struct trace_uprobe *find_probe_event(const char *event, const char *group) 382 { 383 struct dyn_event *pos; 384 struct trace_uprobe *tu; 385 386 for_each_trace_uprobe(tu, pos) 387 if (strcmp(trace_probe_name(&tu->tp), event) == 0 && 388 strcmp(trace_probe_group_name(&tu->tp), group) == 0) 389 return tu; 390 391 return NULL; 392 } 393 394 /* Unregister a trace_uprobe and probe_event */ 395 static int unregister_trace_uprobe(struct trace_uprobe *tu) 396 { 397 int ret; 398 399 if (trace_probe_has_sibling(&tu->tp)) 400 goto unreg; 401 402 /* If there's a reference to the dynamic event */ 403 if (trace_event_dyn_busy(trace_probe_event_call(&tu->tp))) 404 return -EBUSY; 405 406 ret = unregister_uprobe_event(tu); 407 if (ret) 408 return ret; 409 410 unreg: 411 dyn_event_remove(&tu->devent); 412 trace_probe_unlink(&tu->tp); 413 free_trace_uprobe(tu); 414 return 0; 415 } 416 417 static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig, 418 struct trace_uprobe *comp) 419 { 420 struct trace_probe_event *tpe = orig->tp.event; 421 struct inode *comp_inode = d_real_inode(comp->path.dentry); 422 int i; 423 424 list_for_each_entry(orig, &tpe->probes, tp.list) { 425 if (comp_inode != d_real_inode(orig->path.dentry) || 426 comp->offset != orig->offset) 427 continue; 428 429 /* 430 * trace_probe_compare_arg_type() ensured that nr_args and 431 * each argument name and type are same. Let's compare comm. 432 */ 433 for (i = 0; i < orig->tp.nr_args; i++) { 434 if (strcmp(orig->tp.args[i].comm, 435 comp->tp.args[i].comm)) 436 break; 437 } 438 439 if (i == orig->tp.nr_args) 440 return true; 441 } 442 443 return false; 444 } 445 446 static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to) 447 { 448 int ret; 449 450 ret = trace_probe_compare_arg_type(&tu->tp, &to->tp); 451 if (ret) { 452 /* Note that argument starts index = 2 */ 453 trace_probe_log_set_index(ret + 1); 454 trace_probe_log_err(0, DIFF_ARG_TYPE); 455 return -EEXIST; 456 } 457 if (trace_uprobe_has_same_uprobe(to, tu)) { 458 trace_probe_log_set_index(0); 459 trace_probe_log_err(0, SAME_PROBE); 460 return -EEXIST; 461 } 462 463 /* Append to existing event */ 464 ret = trace_probe_append(&tu->tp, &to->tp); 465 if (!ret) 466 dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp)); 467 468 return ret; 469 } 470 471 /* 472 * Uprobe with multiple reference counter is not allowed. i.e. 473 * If inode and offset matches, reference counter offset *must* 474 * match as well. Though, there is one exception: If user is 475 * replacing old trace_uprobe with new one(same group/event), 476 * then we allow same uprobe with new reference counter as far 477 * as the new one does not conflict with any other existing 478 * ones. 479 */ 480 static int validate_ref_ctr_offset(struct trace_uprobe *new) 481 { 482 struct dyn_event *pos; 483 struct trace_uprobe *tmp; 484 struct inode *new_inode = d_real_inode(new->path.dentry); 485 486 for_each_trace_uprobe(tmp, pos) { 487 if (new_inode == d_real_inode(tmp->path.dentry) && 488 new->offset == tmp->offset && 489 new->ref_ctr_offset != tmp->ref_ctr_offset) { 490 pr_warn("Reference counter offset mismatch."); 491 return -EINVAL; 492 } 493 } 494 return 0; 495 } 496 497 /* Register a trace_uprobe and probe_event */ 498 static int register_trace_uprobe(struct trace_uprobe *tu) 499 { 500 struct trace_uprobe *old_tu; 501 int ret; 502 503 guard(mutex)(&event_mutex); 504 505 ret = validate_ref_ctr_offset(tu); 506 if (ret) 507 return ret; 508 509 /* register as an event */ 510 old_tu = find_probe_event(trace_probe_name(&tu->tp), 511 trace_probe_group_name(&tu->tp)); 512 if (old_tu) { 513 if (is_ret_probe(tu) != is_ret_probe(old_tu)) { 514 trace_probe_log_set_index(0); 515 trace_probe_log_err(0, DIFF_PROBE_TYPE); 516 return -EEXIST; 517 } 518 return append_trace_uprobe(tu, old_tu); 519 } 520 521 ret = register_uprobe_event(tu); 522 if (ret) { 523 if (ret == -EEXIST) { 524 trace_probe_log_set_index(0); 525 trace_probe_log_err(0, EVENT_EXIST); 526 } else 527 pr_warn("Failed to register probe event(%d)\n", ret); 528 return ret; 529 } 530 531 dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp)); 532 533 return ret; 534 } 535 536 /* 537 * Argument syntax: 538 * - Add uprobe: p|r[:[GRP/][EVENT]] PATH:OFFSET[%return][(REF)] [FETCHARGS] 539 */ 540 static int __trace_uprobe_create(int argc, const char **argv) 541 { 542 const char *event = NULL, *group = UPROBE_EVENT_SYSTEM; 543 char *arg, *filename, *rctr, *rctr_end, *tmp; 544 unsigned long offset, ref_ctr_offset; 545 char *gbuf __free(kfree) = NULL; 546 char *buf __free(kfree) = NULL; 547 enum probe_print_type ptype; 548 struct trace_uprobe *tu; 549 bool is_return = false; 550 struct path path; 551 int i, ret; 552 553 ref_ctr_offset = 0; 554 555 switch (argv[0][0]) { 556 case 'r': 557 is_return = true; 558 break; 559 case 'p': 560 break; 561 default: 562 return -ECANCELED; 563 } 564 565 if (argc < 2) 566 return -ECANCELED; 567 568 trace_probe_log_init("trace_uprobe", argc, argv); 569 570 if (argc - 2 > MAX_TRACE_ARGS) { 571 trace_probe_log_set_index(2); 572 trace_probe_log_err(0, TOO_MANY_ARGS); 573 return -E2BIG; 574 } 575 576 if (argv[0][1] == ':') 577 event = &argv[0][2]; 578 579 if (!strchr(argv[1], '/')) 580 return -ECANCELED; 581 582 filename = kstrdup(argv[1], GFP_KERNEL); 583 if (!filename) 584 return -ENOMEM; 585 586 /* Find the last occurrence, in case the path contains ':' too. */ 587 arg = strrchr(filename, ':'); 588 if (!arg || !isdigit(arg[1])) { 589 kfree(filename); 590 return -ECANCELED; 591 } 592 593 trace_probe_log_set_index(1); /* filename is the 2nd argument */ 594 595 *arg++ = '\0'; 596 ret = kern_path(filename, LOOKUP_FOLLOW, &path); 597 if (ret) { 598 trace_probe_log_err(0, FILE_NOT_FOUND); 599 kfree(filename); 600 trace_probe_log_clear(); 601 return ret; 602 } 603 if (!d_is_reg(path.dentry)) { 604 trace_probe_log_err(0, NO_REGULAR_FILE); 605 ret = -EINVAL; 606 goto fail_address_parse; 607 } 608 609 /* Parse reference counter offset if specified. */ 610 rctr = strchr(arg, '('); 611 if (rctr) { 612 rctr_end = strchr(rctr, ')'); 613 if (!rctr_end) { 614 ret = -EINVAL; 615 rctr_end = rctr + strlen(rctr); 616 trace_probe_log_err(rctr_end - filename, 617 REFCNT_OPEN_BRACE); 618 goto fail_address_parse; 619 } else if (rctr_end[1] != '\0') { 620 ret = -EINVAL; 621 trace_probe_log_err(rctr_end + 1 - filename, 622 BAD_REFCNT_SUFFIX); 623 goto fail_address_parse; 624 } 625 626 *rctr++ = '\0'; 627 *rctr_end = '\0'; 628 ret = kstrtoul(rctr, 0, &ref_ctr_offset); 629 if (ret) { 630 trace_probe_log_err(rctr - filename, BAD_REFCNT); 631 goto fail_address_parse; 632 } 633 } 634 635 /* Check if there is %return suffix */ 636 tmp = strchr(arg, '%'); 637 if (tmp) { 638 if (!strcmp(tmp, "%return")) { 639 *tmp = '\0'; 640 is_return = true; 641 } else { 642 trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX); 643 ret = -EINVAL; 644 goto fail_address_parse; 645 } 646 } 647 648 /* Parse uprobe offset. */ 649 ret = kstrtoul(arg, 0, &offset); 650 if (ret) { 651 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS); 652 goto fail_address_parse; 653 } 654 655 /* setup a probe */ 656 trace_probe_log_set_index(0); 657 if (event) { 658 gbuf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL); 659 if (!gbuf) 660 goto fail_mem; 661 662 ret = traceprobe_parse_event_name(&event, &group, gbuf, 663 event - argv[0]); 664 if (ret) 665 goto fail_address_parse; 666 } 667 668 if (!event) { 669 char *tail; 670 char *ptr; 671 672 tail = kstrdup(kbasename(filename), GFP_KERNEL); 673 if (!tail) 674 goto fail_mem; 675 676 ptr = strpbrk(tail, ".-_"); 677 if (ptr) 678 *ptr = '\0'; 679 680 buf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL); 681 if (!buf) 682 goto fail_mem; 683 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset); 684 event = buf; 685 kfree(tail); 686 } 687 688 argc -= 2; 689 argv += 2; 690 691 tu = alloc_trace_uprobe(group, event, argc, is_return); 692 if (IS_ERR(tu)) { 693 ret = PTR_ERR(tu); 694 /* This must return -ENOMEM otherwise there is a bug */ 695 WARN_ON_ONCE(ret != -ENOMEM); 696 goto fail_address_parse; 697 } 698 tu->offset = offset; 699 tu->ref_ctr_offset = ref_ctr_offset; 700 tu->path = path; 701 tu->filename = filename; 702 703 /* parse arguments */ 704 for (i = 0; i < argc; i++) { 705 struct traceprobe_parse_context *ctx __free(traceprobe_parse_context) 706 = kzalloc(sizeof(*ctx), GFP_KERNEL); 707 708 if (!ctx) { 709 ret = -ENOMEM; 710 goto error; 711 } 712 ctx->flags = (is_return ? TPARG_FL_RETURN : 0) | TPARG_FL_USER; 713 trace_probe_log_set_index(i + 2); 714 ret = traceprobe_parse_probe_arg(&tu->tp, i, argv[i], ctx); 715 if (ret) 716 goto error; 717 } 718 719 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; 720 ret = traceprobe_set_print_fmt(&tu->tp, ptype); 721 if (ret < 0) 722 goto error; 723 724 ret = register_trace_uprobe(tu); 725 if (!ret) 726 goto out; 727 728 error: 729 free_trace_uprobe(tu); 730 out: 731 trace_probe_log_clear(); 732 return ret; 733 734 fail_mem: 735 ret = -ENOMEM; 736 737 fail_address_parse: 738 trace_probe_log_clear(); 739 path_put(&path); 740 kfree(filename); 741 742 return ret; 743 } 744 745 int trace_uprobe_create(const char *raw_command) 746 { 747 return trace_probe_create(raw_command, __trace_uprobe_create); 748 } 749 750 static int create_or_delete_trace_uprobe(const char *raw_command) 751 { 752 int ret; 753 754 if (raw_command[0] == '-') 755 return dyn_event_release(raw_command, &trace_uprobe_ops); 756 757 ret = dyn_event_create(raw_command, &trace_uprobe_ops); 758 return ret == -ECANCELED ? -EINVAL : ret; 759 } 760 761 static int trace_uprobe_release(struct dyn_event *ev) 762 { 763 struct trace_uprobe *tu = to_trace_uprobe(ev); 764 765 return unregister_trace_uprobe(tu); 766 } 767 768 /* Probes listing interfaces */ 769 static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev) 770 { 771 struct trace_uprobe *tu = to_trace_uprobe(ev); 772 char c = is_ret_probe(tu) ? 'r' : 'p'; 773 int i; 774 775 seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp), 776 trace_probe_name(&tu->tp), tu->filename, 777 (int)(sizeof(void *) * 2), tu->offset); 778 779 if (tu->ref_ctr_offset) 780 seq_printf(m, "(0x%lx)", tu->ref_ctr_offset); 781 782 for (i = 0; i < tu->tp.nr_args; i++) 783 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm); 784 785 seq_putc(m, '\n'); 786 return 0; 787 } 788 789 static int probes_seq_show(struct seq_file *m, void *v) 790 { 791 struct dyn_event *ev = v; 792 793 if (!is_trace_uprobe(ev)) 794 return 0; 795 796 return trace_uprobe_show(m, ev); 797 } 798 799 static const struct seq_operations probes_seq_op = { 800 .start = dyn_event_seq_start, 801 .next = dyn_event_seq_next, 802 .stop = dyn_event_seq_stop, 803 .show = probes_seq_show 804 }; 805 806 static int probes_open(struct inode *inode, struct file *file) 807 { 808 int ret; 809 810 ret = security_locked_down(LOCKDOWN_TRACEFS); 811 if (ret) 812 return ret; 813 814 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { 815 ret = dyn_events_release_all(&trace_uprobe_ops); 816 if (ret) 817 return ret; 818 } 819 820 return seq_open(file, &probes_seq_op); 821 } 822 823 static ssize_t probes_write(struct file *file, const char __user *buffer, 824 size_t count, loff_t *ppos) 825 { 826 return trace_parse_run_command(file, buffer, count, ppos, 827 create_or_delete_trace_uprobe); 828 } 829 830 static const struct file_operations uprobe_events_ops = { 831 .owner = THIS_MODULE, 832 .open = probes_open, 833 .read = seq_read, 834 .llseek = seq_lseek, 835 .release = seq_release, 836 .write = probes_write, 837 }; 838 839 /* Probes profiling interfaces */ 840 static int probes_profile_seq_show(struct seq_file *m, void *v) 841 { 842 struct dyn_event *ev = v; 843 struct trace_uprobe *tu; 844 unsigned long nhits; 845 int cpu; 846 847 if (!is_trace_uprobe(ev)) 848 return 0; 849 850 tu = to_trace_uprobe(ev); 851 852 nhits = 0; 853 for_each_possible_cpu(cpu) { 854 nhits += per_cpu(*tu->nhits, cpu); 855 } 856 857 seq_printf(m, " %s %-44s %15lu\n", tu->filename, 858 trace_probe_name(&tu->tp), nhits); 859 return 0; 860 } 861 862 static const struct seq_operations profile_seq_op = { 863 .start = dyn_event_seq_start, 864 .next = dyn_event_seq_next, 865 .stop = dyn_event_seq_stop, 866 .show = probes_profile_seq_show 867 }; 868 869 static int profile_open(struct inode *inode, struct file *file) 870 { 871 int ret; 872 873 ret = security_locked_down(LOCKDOWN_TRACEFS); 874 if (ret) 875 return ret; 876 877 return seq_open(file, &profile_seq_op); 878 } 879 880 static const struct file_operations uprobe_profile_ops = { 881 .owner = THIS_MODULE, 882 .open = profile_open, 883 .read = seq_read, 884 .llseek = seq_lseek, 885 .release = seq_release, 886 }; 887 888 struct uprobe_cpu_buffer { 889 struct mutex mutex; 890 void *buf; 891 int dsize; 892 }; 893 static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer; 894 static int uprobe_buffer_refcnt; 895 #define MAX_UCB_BUFFER_SIZE PAGE_SIZE 896 897 static int uprobe_buffer_init(void) 898 { 899 int cpu, err_cpu; 900 901 uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer); 902 if (uprobe_cpu_buffer == NULL) 903 return -ENOMEM; 904 905 for_each_possible_cpu(cpu) { 906 struct page *p = alloc_pages_node(cpu_to_node(cpu), 907 GFP_KERNEL, 0); 908 if (p == NULL) { 909 err_cpu = cpu; 910 goto err; 911 } 912 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p); 913 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex); 914 } 915 916 return 0; 917 918 err: 919 for_each_possible_cpu(cpu) { 920 if (cpu == err_cpu) 921 break; 922 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf); 923 } 924 925 free_percpu(uprobe_cpu_buffer); 926 return -ENOMEM; 927 } 928 929 static int uprobe_buffer_enable(void) 930 { 931 int ret = 0; 932 933 BUG_ON(!mutex_is_locked(&event_mutex)); 934 935 if (uprobe_buffer_refcnt++ == 0) { 936 ret = uprobe_buffer_init(); 937 if (ret < 0) 938 uprobe_buffer_refcnt--; 939 } 940 941 return ret; 942 } 943 944 static void uprobe_buffer_disable(void) 945 { 946 int cpu; 947 948 BUG_ON(!mutex_is_locked(&event_mutex)); 949 950 if (--uprobe_buffer_refcnt == 0) { 951 for_each_possible_cpu(cpu) 952 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, 953 cpu)->buf); 954 955 free_percpu(uprobe_cpu_buffer); 956 uprobe_cpu_buffer = NULL; 957 } 958 } 959 960 static struct uprobe_cpu_buffer *uprobe_buffer_get(void) 961 { 962 struct uprobe_cpu_buffer *ucb; 963 int cpu; 964 965 cpu = raw_smp_processor_id(); 966 ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu); 967 968 /* 969 * Use per-cpu buffers for fastest access, but we might migrate 970 * so the mutex makes sure we have sole access to it. 971 */ 972 mutex_lock(&ucb->mutex); 973 974 return ucb; 975 } 976 977 static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb) 978 { 979 if (!ucb) 980 return; 981 mutex_unlock(&ucb->mutex); 982 } 983 984 static struct uprobe_cpu_buffer *prepare_uprobe_buffer(struct trace_uprobe *tu, 985 struct pt_regs *regs, 986 struct uprobe_cpu_buffer **ucbp) 987 { 988 struct uprobe_cpu_buffer *ucb; 989 int dsize, esize; 990 991 if (*ucbp) 992 return *ucbp; 993 994 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 995 dsize = __get_data_size(&tu->tp, regs, NULL); 996 997 ucb = uprobe_buffer_get(); 998 ucb->dsize = tu->tp.size + dsize; 999 1000 if (WARN_ON_ONCE(ucb->dsize > MAX_UCB_BUFFER_SIZE)) { 1001 ucb->dsize = MAX_UCB_BUFFER_SIZE; 1002 dsize = MAX_UCB_BUFFER_SIZE - tu->tp.size; 1003 } 1004 1005 store_trace_args(ucb->buf, &tu->tp, regs, NULL, esize, dsize); 1006 1007 *ucbp = ucb; 1008 return ucb; 1009 } 1010 1011 static void __uprobe_trace_func(struct trace_uprobe *tu, 1012 unsigned long func, struct pt_regs *regs, 1013 struct uprobe_cpu_buffer *ucb, 1014 struct trace_event_file *trace_file) 1015 { 1016 struct uprobe_trace_entry_head *entry; 1017 struct trace_event_buffer fbuffer; 1018 void *data; 1019 int size, esize; 1020 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 1021 1022 WARN_ON(call != trace_file->event_call); 1023 1024 if (trace_trigger_soft_disabled(trace_file)) 1025 return; 1026 1027 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1028 size = esize + ucb->dsize; 1029 entry = trace_event_buffer_reserve(&fbuffer, trace_file, size); 1030 if (!entry) 1031 return; 1032 1033 if (is_ret_probe(tu)) { 1034 entry->vaddr[0] = func; 1035 entry->vaddr[1] = instruction_pointer(regs); 1036 data = DATAOF_TRACE_ENTRY(entry, true); 1037 } else { 1038 entry->vaddr[0] = instruction_pointer(regs); 1039 data = DATAOF_TRACE_ENTRY(entry, false); 1040 } 1041 1042 memcpy(data, ucb->buf, ucb->dsize); 1043 1044 trace_event_buffer_commit(&fbuffer); 1045 } 1046 1047 /* uprobe handler */ 1048 static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs, 1049 struct uprobe_cpu_buffer **ucbp) 1050 { 1051 struct event_file_link *link; 1052 struct uprobe_cpu_buffer *ucb; 1053 1054 if (is_ret_probe(tu)) 1055 return 0; 1056 1057 ucb = prepare_uprobe_buffer(tu, regs, ucbp); 1058 1059 rcu_read_lock(); 1060 trace_probe_for_each_link_rcu(link, &tu->tp) 1061 __uprobe_trace_func(tu, 0, regs, ucb, link->file); 1062 rcu_read_unlock(); 1063 1064 return 0; 1065 } 1066 1067 static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func, 1068 struct pt_regs *regs, 1069 struct uprobe_cpu_buffer **ucbp) 1070 { 1071 struct event_file_link *link; 1072 struct uprobe_cpu_buffer *ucb; 1073 1074 ucb = prepare_uprobe_buffer(tu, regs, ucbp); 1075 1076 rcu_read_lock(); 1077 trace_probe_for_each_link_rcu(link, &tu->tp) 1078 __uprobe_trace_func(tu, func, regs, ucb, link->file); 1079 rcu_read_unlock(); 1080 } 1081 1082 /* Event entry printers */ 1083 static enum print_line_t 1084 print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) 1085 { 1086 struct uprobe_trace_entry_head *entry; 1087 struct trace_seq *s = &iter->seq; 1088 struct trace_uprobe *tu; 1089 u8 *data; 1090 1091 entry = (struct uprobe_trace_entry_head *)iter->ent; 1092 tu = trace_uprobe_primary_from_call( 1093 container_of(event, struct trace_event_call, event)); 1094 if (unlikely(!tu)) 1095 goto out; 1096 1097 if (is_ret_probe(tu)) { 1098 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)", 1099 trace_probe_name(&tu->tp), 1100 entry->vaddr[1], entry->vaddr[0]); 1101 data = DATAOF_TRACE_ENTRY(entry, true); 1102 } else { 1103 trace_seq_printf(s, "%s: (0x%lx)", 1104 trace_probe_name(&tu->tp), 1105 entry->vaddr[0]); 1106 data = DATAOF_TRACE_ENTRY(entry, false); 1107 } 1108 1109 if (trace_probe_print_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0) 1110 goto out; 1111 1112 trace_seq_putc(s, '\n'); 1113 1114 out: 1115 return trace_handle_return(s); 1116 } 1117 1118 typedef bool (*filter_func_t)(struct uprobe_consumer *self, struct mm_struct *mm); 1119 1120 static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter) 1121 { 1122 struct inode *inode = d_real_inode(tu->path.dentry); 1123 struct uprobe *uprobe; 1124 1125 tu->consumer.filter = filter; 1126 uprobe = uprobe_register(inode, tu->offset, tu->ref_ctr_offset, &tu->consumer); 1127 if (IS_ERR(uprobe)) 1128 return PTR_ERR(uprobe); 1129 1130 tu->uprobe = uprobe; 1131 return 0; 1132 } 1133 1134 static void __probe_event_disable(struct trace_probe *tp) 1135 { 1136 struct trace_uprobe *tu; 1137 bool sync = false; 1138 1139 tu = container_of(tp, struct trace_uprobe, tp); 1140 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter)); 1141 1142 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1143 if (!tu->uprobe) 1144 continue; 1145 1146 uprobe_unregister_nosync(tu->uprobe, &tu->consumer); 1147 sync = true; 1148 tu->uprobe = NULL; 1149 } 1150 if (sync) 1151 uprobe_unregister_sync(); 1152 } 1153 1154 static int probe_event_enable(struct trace_event_call *call, 1155 struct trace_event_file *file, filter_func_t filter) 1156 { 1157 struct trace_probe *tp; 1158 struct trace_uprobe *tu; 1159 bool enabled; 1160 int ret; 1161 1162 tp = trace_probe_primary_from_call(call); 1163 if (WARN_ON_ONCE(!tp)) 1164 return -ENODEV; 1165 enabled = trace_probe_is_enabled(tp); 1166 1167 /* This may also change "enabled" state */ 1168 if (file) { 1169 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE)) 1170 return -EINTR; 1171 1172 ret = trace_probe_add_file(tp, file); 1173 if (ret < 0) 1174 return ret; 1175 } else { 1176 if (trace_probe_test_flag(tp, TP_FLAG_TRACE)) 1177 return -EINTR; 1178 1179 trace_probe_set_flag(tp, TP_FLAG_PROFILE); 1180 } 1181 1182 tu = container_of(tp, struct trace_uprobe, tp); 1183 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter)); 1184 1185 if (enabled) 1186 return 0; 1187 1188 ret = uprobe_buffer_enable(); 1189 if (ret) 1190 goto err_flags; 1191 1192 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1193 ret = trace_uprobe_enable(tu, filter); 1194 if (ret) { 1195 __probe_event_disable(tp); 1196 goto err_buffer; 1197 } 1198 } 1199 1200 return 0; 1201 1202 err_buffer: 1203 uprobe_buffer_disable(); 1204 1205 err_flags: 1206 if (file) 1207 trace_probe_remove_file(tp, file); 1208 else 1209 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 1210 1211 return ret; 1212 } 1213 1214 static void probe_event_disable(struct trace_event_call *call, 1215 struct trace_event_file *file) 1216 { 1217 struct trace_probe *tp; 1218 1219 tp = trace_probe_primary_from_call(call); 1220 if (WARN_ON_ONCE(!tp)) 1221 return; 1222 1223 if (!trace_probe_is_enabled(tp)) 1224 return; 1225 1226 if (file) { 1227 if (trace_probe_remove_file(tp, file) < 0) 1228 return; 1229 1230 if (trace_probe_is_enabled(tp)) 1231 return; 1232 } else 1233 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 1234 1235 __probe_event_disable(tp); 1236 uprobe_buffer_disable(); 1237 } 1238 1239 static int uprobe_event_define_fields(struct trace_event_call *event_call) 1240 { 1241 int ret, size; 1242 struct uprobe_trace_entry_head field; 1243 struct trace_uprobe *tu; 1244 1245 tu = trace_uprobe_primary_from_call(event_call); 1246 if (unlikely(!tu)) 1247 return -ENODEV; 1248 1249 if (is_ret_probe(tu)) { 1250 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0); 1251 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0); 1252 size = SIZEOF_TRACE_ENTRY(true); 1253 } else { 1254 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0); 1255 size = SIZEOF_TRACE_ENTRY(false); 1256 } 1257 1258 return traceprobe_define_arg_fields(event_call, size, &tu->tp); 1259 } 1260 1261 #ifdef CONFIG_PERF_EVENTS 1262 static bool 1263 __uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm) 1264 { 1265 struct perf_event *event; 1266 1267 list_for_each_entry(event, &filter->perf_events, hw.tp_list) { 1268 if (event->hw.target->mm == mm) 1269 return true; 1270 } 1271 1272 return false; 1273 } 1274 1275 static inline bool 1276 trace_uprobe_filter_event(struct trace_uprobe_filter *filter, 1277 struct perf_event *event) 1278 { 1279 return __uprobe_perf_filter(filter, event->hw.target->mm); 1280 } 1281 1282 static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter, 1283 struct perf_event *event) 1284 { 1285 bool done; 1286 1287 write_lock(&filter->rwlock); 1288 if (event->hw.target) { 1289 list_del(&event->hw.tp_list); 1290 done = filter->nr_systemwide || 1291 (event->hw.target->flags & PF_EXITING) || 1292 trace_uprobe_filter_event(filter, event); 1293 } else { 1294 filter->nr_systemwide--; 1295 done = filter->nr_systemwide; 1296 } 1297 write_unlock(&filter->rwlock); 1298 1299 return done; 1300 } 1301 1302 /* This returns true if the filter always covers target mm */ 1303 static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter, 1304 struct perf_event *event) 1305 { 1306 bool done; 1307 1308 write_lock(&filter->rwlock); 1309 if (event->hw.target) { 1310 /* 1311 * event->parent != NULL means copy_process(), we can avoid 1312 * uprobe_apply(). current->mm must be probed and we can rely 1313 * on dup_mmap() which preserves the already installed bp's. 1314 * 1315 * attr.enable_on_exec means that exec/mmap will install the 1316 * breakpoints we need. 1317 */ 1318 done = filter->nr_systemwide || 1319 event->parent || event->attr.enable_on_exec || 1320 trace_uprobe_filter_event(filter, event); 1321 list_add(&event->hw.tp_list, &filter->perf_events); 1322 } else { 1323 done = filter->nr_systemwide; 1324 filter->nr_systemwide++; 1325 } 1326 write_unlock(&filter->rwlock); 1327 1328 return done; 1329 } 1330 1331 static int uprobe_perf_close(struct trace_event_call *call, 1332 struct perf_event *event) 1333 { 1334 struct trace_probe *tp; 1335 struct trace_uprobe *tu; 1336 int ret = 0; 1337 1338 tp = trace_probe_primary_from_call(call); 1339 if (WARN_ON_ONCE(!tp)) 1340 return -ENODEV; 1341 1342 tu = container_of(tp, struct trace_uprobe, tp); 1343 if (trace_uprobe_filter_remove(tu->tp.event->filter, event)) 1344 return 0; 1345 1346 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1347 ret = uprobe_apply(tu->uprobe, &tu->consumer, false); 1348 if (ret) 1349 break; 1350 } 1351 1352 return ret; 1353 } 1354 1355 static int uprobe_perf_open(struct trace_event_call *call, 1356 struct perf_event *event) 1357 { 1358 struct trace_probe *tp; 1359 struct trace_uprobe *tu; 1360 int err = 0; 1361 1362 tp = trace_probe_primary_from_call(call); 1363 if (WARN_ON_ONCE(!tp)) 1364 return -ENODEV; 1365 1366 tu = container_of(tp, struct trace_uprobe, tp); 1367 if (trace_uprobe_filter_add(tu->tp.event->filter, event)) 1368 return 0; 1369 1370 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1371 err = uprobe_apply(tu->uprobe, &tu->consumer, true); 1372 if (err) { 1373 uprobe_perf_close(call, event); 1374 break; 1375 } 1376 } 1377 1378 return err; 1379 } 1380 1381 static bool uprobe_perf_filter(struct uprobe_consumer *uc, struct mm_struct *mm) 1382 { 1383 struct trace_uprobe_filter *filter; 1384 struct trace_uprobe *tu; 1385 int ret; 1386 1387 tu = container_of(uc, struct trace_uprobe, consumer); 1388 filter = tu->tp.event->filter; 1389 1390 /* 1391 * speculative short-circuiting check to avoid unnecessarily taking 1392 * filter->rwlock below, if the uprobe has system-wide consumer 1393 */ 1394 if (READ_ONCE(filter->nr_systemwide)) 1395 return true; 1396 1397 read_lock(&filter->rwlock); 1398 ret = __uprobe_perf_filter(filter, mm); 1399 read_unlock(&filter->rwlock); 1400 1401 return ret; 1402 } 1403 1404 static void __uprobe_perf_func(struct trace_uprobe *tu, 1405 unsigned long func, struct pt_regs *regs, 1406 struct uprobe_cpu_buffer **ucbp) 1407 { 1408 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 1409 struct uprobe_trace_entry_head *entry; 1410 struct uprobe_cpu_buffer *ucb; 1411 struct hlist_head *head; 1412 void *data; 1413 int size, esize; 1414 int rctx; 1415 1416 #ifdef CONFIG_BPF_EVENTS 1417 if (bpf_prog_array_valid(call)) { 1418 const struct bpf_prog_array *array; 1419 u32 ret; 1420 1421 rcu_read_lock_trace(); 1422 array = rcu_dereference_check(call->prog_array, rcu_read_lock_trace_held()); 1423 ret = bpf_prog_run_array_uprobe(array, regs, bpf_prog_run); 1424 rcu_read_unlock_trace(); 1425 if (!ret) 1426 return; 1427 } 1428 #endif /* CONFIG_BPF_EVENTS */ 1429 1430 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1431 1432 ucb = prepare_uprobe_buffer(tu, regs, ucbp); 1433 size = esize + ucb->dsize; 1434 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32); 1435 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) 1436 return; 1437 1438 preempt_disable(); 1439 head = this_cpu_ptr(call->perf_events); 1440 if (hlist_empty(head)) 1441 goto out; 1442 1443 entry = perf_trace_buf_alloc(size, NULL, &rctx); 1444 if (!entry) 1445 goto out; 1446 1447 if (is_ret_probe(tu)) { 1448 entry->vaddr[0] = func; 1449 entry->vaddr[1] = instruction_pointer(regs); 1450 data = DATAOF_TRACE_ENTRY(entry, true); 1451 } else { 1452 entry->vaddr[0] = instruction_pointer(regs); 1453 data = DATAOF_TRACE_ENTRY(entry, false); 1454 } 1455 1456 memcpy(data, ucb->buf, ucb->dsize); 1457 1458 if (size - esize > ucb->dsize) 1459 memset(data + ucb->dsize, 0, size - esize - ucb->dsize); 1460 1461 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, 1462 head, NULL); 1463 out: 1464 preempt_enable(); 1465 } 1466 1467 /* uprobe profile handler */ 1468 static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs, 1469 struct uprobe_cpu_buffer **ucbp) 1470 { 1471 if (!uprobe_perf_filter(&tu->consumer, current->mm)) 1472 return UPROBE_HANDLER_REMOVE; 1473 1474 if (!is_ret_probe(tu)) 1475 __uprobe_perf_func(tu, 0, regs, ucbp); 1476 return 0; 1477 } 1478 1479 static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func, 1480 struct pt_regs *regs, 1481 struct uprobe_cpu_buffer **ucbp) 1482 { 1483 __uprobe_perf_func(tu, func, regs, ucbp); 1484 } 1485 1486 int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type, 1487 const char **filename, u64 *probe_offset, 1488 u64 *probe_addr, bool perf_type_tracepoint) 1489 { 1490 const char *pevent = trace_event_name(event->tp_event); 1491 const char *group = event->tp_event->class->system; 1492 struct trace_uprobe *tu; 1493 1494 if (perf_type_tracepoint) 1495 tu = find_probe_event(pevent, group); 1496 else 1497 tu = trace_uprobe_primary_from_call(event->tp_event); 1498 if (!tu) 1499 return -EINVAL; 1500 1501 *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE 1502 : BPF_FD_TYPE_UPROBE; 1503 *filename = tu->filename; 1504 *probe_offset = tu->offset; 1505 *probe_addr = tu->ref_ctr_offset; 1506 return 0; 1507 } 1508 #endif /* CONFIG_PERF_EVENTS */ 1509 1510 static int 1511 trace_uprobe_register(struct trace_event_call *event, enum trace_reg type, 1512 void *data) 1513 { 1514 struct trace_event_file *file = data; 1515 1516 switch (type) { 1517 case TRACE_REG_REGISTER: 1518 return probe_event_enable(event, file, NULL); 1519 1520 case TRACE_REG_UNREGISTER: 1521 probe_event_disable(event, file); 1522 return 0; 1523 1524 #ifdef CONFIG_PERF_EVENTS 1525 case TRACE_REG_PERF_REGISTER: 1526 return probe_event_enable(event, NULL, uprobe_perf_filter); 1527 1528 case TRACE_REG_PERF_UNREGISTER: 1529 probe_event_disable(event, NULL); 1530 return 0; 1531 1532 case TRACE_REG_PERF_OPEN: 1533 return uprobe_perf_open(event, data); 1534 1535 case TRACE_REG_PERF_CLOSE: 1536 return uprobe_perf_close(event, data); 1537 1538 #endif 1539 default: 1540 return 0; 1541 } 1542 } 1543 1544 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs, 1545 __u64 *data) 1546 { 1547 struct trace_uprobe *tu; 1548 struct uprobe_dispatch_data udd; 1549 struct uprobe_cpu_buffer *ucb = NULL; 1550 int ret = 0; 1551 1552 tu = container_of(con, struct trace_uprobe, consumer); 1553 1554 this_cpu_inc(*tu->nhits); 1555 1556 udd.tu = tu; 1557 udd.bp_addr = instruction_pointer(regs); 1558 1559 current->utask->vaddr = (unsigned long) &udd; 1560 1561 if (WARN_ON_ONCE(!uprobe_cpu_buffer)) 1562 return 0; 1563 1564 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) 1565 ret |= uprobe_trace_func(tu, regs, &ucb); 1566 1567 #ifdef CONFIG_PERF_EVENTS 1568 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) 1569 ret |= uprobe_perf_func(tu, regs, &ucb); 1570 #endif 1571 uprobe_buffer_put(ucb); 1572 return ret; 1573 } 1574 1575 static int uretprobe_dispatcher(struct uprobe_consumer *con, 1576 unsigned long func, struct pt_regs *regs, 1577 __u64 *data) 1578 { 1579 struct trace_uprobe *tu; 1580 struct uprobe_dispatch_data udd; 1581 struct uprobe_cpu_buffer *ucb = NULL; 1582 1583 tu = container_of(con, struct trace_uprobe, consumer); 1584 1585 udd.tu = tu; 1586 udd.bp_addr = func; 1587 1588 current->utask->vaddr = (unsigned long) &udd; 1589 1590 if (WARN_ON_ONCE(!uprobe_cpu_buffer)) 1591 return 0; 1592 1593 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) 1594 uretprobe_trace_func(tu, func, regs, &ucb); 1595 1596 #ifdef CONFIG_PERF_EVENTS 1597 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) 1598 uretprobe_perf_func(tu, func, regs, &ucb); 1599 #endif 1600 uprobe_buffer_put(ucb); 1601 return 0; 1602 } 1603 1604 static struct trace_event_functions uprobe_funcs = { 1605 .trace = print_uprobe_event 1606 }; 1607 1608 static struct trace_event_fields uprobe_fields_array[] = { 1609 { .type = TRACE_FUNCTION_TYPE, 1610 .define_fields = uprobe_event_define_fields }, 1611 {} 1612 }; 1613 1614 static inline void init_trace_event_call(struct trace_uprobe *tu) 1615 { 1616 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 1617 call->event.funcs = &uprobe_funcs; 1618 call->class->fields_array = uprobe_fields_array; 1619 1620 call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY; 1621 call->class->reg = trace_uprobe_register; 1622 } 1623 1624 static int register_uprobe_event(struct trace_uprobe *tu) 1625 { 1626 init_trace_event_call(tu); 1627 1628 return trace_probe_register_event_call(&tu->tp); 1629 } 1630 1631 static int unregister_uprobe_event(struct trace_uprobe *tu) 1632 { 1633 return trace_probe_unregister_event_call(&tu->tp); 1634 } 1635 1636 #ifdef CONFIG_PERF_EVENTS 1637 struct trace_event_call * 1638 create_local_trace_uprobe(char *name, unsigned long offs, 1639 unsigned long ref_ctr_offset, bool is_return) 1640 { 1641 enum probe_print_type ptype; 1642 struct trace_uprobe *tu; 1643 struct path path; 1644 int ret; 1645 1646 ret = kern_path(name, LOOKUP_FOLLOW, &path); 1647 if (ret) 1648 return ERR_PTR(ret); 1649 1650 if (!d_is_reg(path.dentry)) { 1651 path_put(&path); 1652 return ERR_PTR(-EINVAL); 1653 } 1654 1655 /* 1656 * local trace_kprobes are not added to dyn_event, so they are never 1657 * searched in find_trace_kprobe(). Therefore, there is no concern of 1658 * duplicated name "DUMMY_EVENT" here. 1659 */ 1660 tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0, 1661 is_return); 1662 1663 if (IS_ERR(tu)) { 1664 pr_info("Failed to allocate trace_uprobe.(%d)\n", 1665 (int)PTR_ERR(tu)); 1666 path_put(&path); 1667 return ERR_CAST(tu); 1668 } 1669 1670 tu->offset = offs; 1671 tu->path = path; 1672 tu->ref_ctr_offset = ref_ctr_offset; 1673 tu->filename = kstrdup(name, GFP_KERNEL); 1674 if (!tu->filename) { 1675 ret = -ENOMEM; 1676 goto error; 1677 } 1678 1679 init_trace_event_call(tu); 1680 1681 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; 1682 if (traceprobe_set_print_fmt(&tu->tp, ptype) < 0) { 1683 ret = -ENOMEM; 1684 goto error; 1685 } 1686 1687 return trace_probe_event_call(&tu->tp); 1688 error: 1689 free_trace_uprobe(tu); 1690 return ERR_PTR(ret); 1691 } 1692 1693 void destroy_local_trace_uprobe(struct trace_event_call *event_call) 1694 { 1695 struct trace_uprobe *tu; 1696 1697 tu = trace_uprobe_primary_from_call(event_call); 1698 1699 free_trace_uprobe(tu); 1700 } 1701 #endif /* CONFIG_PERF_EVENTS */ 1702 1703 /* Make a trace interface for controlling probe points */ 1704 static __init int init_uprobe_trace(void) 1705 { 1706 int ret; 1707 1708 ret = dyn_event_register(&trace_uprobe_ops); 1709 if (ret) 1710 return ret; 1711 1712 ret = tracing_init_dentry(); 1713 if (ret) 1714 return 0; 1715 1716 trace_create_file("uprobe_events", TRACE_MODE_WRITE, NULL, 1717 NULL, &uprobe_events_ops); 1718 /* Profile interface */ 1719 trace_create_file("uprobe_profile", TRACE_MODE_READ, NULL, 1720 NULL, &uprobe_profile_ops); 1721 return 0; 1722 } 1723 1724 fs_initcall(init_uprobe_trace); 1725