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 27struct 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 39static int trace_uprobe_create(const char *raw_command); 40static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev); 41static int trace_uprobe_release(struct dyn_event *ev); 42static bool trace_uprobe_is_busy(struct dyn_event *ev); 43static bool trace_uprobe_match(const char *system, const char *event, 44 int argc, const char **argv, struct dyn_event *ev); 45 46static 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 */ 57struct 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 69static bool is_trace_uprobe(struct dyn_event *ev) 70{ 71 return ev->ops == &trace_uprobe_ops; 72} 73 74static 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 88static int register_uprobe_event(struct trace_uprobe *tu); 89static int unregister_uprobe_event(struct trace_uprobe *tu); 90 91static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs); 92static int uretprobe_dispatcher(struct uprobe_consumer *con, 93 unsigned long func, struct pt_regs *regs); 94 95#ifdef CONFIG_STACK_GROWSUP 96static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) 97{ 98 return addr - (n * sizeof(long)); 99} 100#else 101static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) 102{ 103 return addr + (n * sizeof(long)); 104} 105#endif 106 107static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n) 108{ 109 unsigned long ret; 110 unsigned long addr = user_stack_pointer(regs); 111 112 addr = adjust_stack_addr(addr, n); 113 114 if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret))) 115 return 0; 116 117 return ret; 118} 119 120/* 121 * Uprobes-specific fetch functions 122 */ 123static nokprobe_inline int 124probe_mem_read(void *dest, void *src, size_t size) 125{ 126 void __user *vaddr = (void __force __user *)src; 127 128 return copy_from_user(dest, vaddr, size) ? -EFAULT : 0; 129} 130 131static nokprobe_inline int 132probe_mem_read_user(void *dest, void *src, size_t size) 133{ 134 return probe_mem_read(dest, src, size); 135} 136 137/* 138 * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max 139 * length and relative data location. 140 */ 141static nokprobe_inline int 142fetch_store_string(unsigned long addr, void *dest, void *base) 143{ 144 long ret; 145 u32 loc = *(u32 *)dest; 146 int maxlen = get_loc_len(loc); 147 u8 *dst = get_loc_data(dest, base); 148 void __user *src = (void __force __user *) addr; 149 150 if (unlikely(!maxlen)) 151 return -ENOMEM; 152 153 if (addr == FETCH_TOKEN_COMM) 154 ret = strscpy(dst, current->comm, maxlen); 155 else 156 ret = strncpy_from_user(dst, src, maxlen); 157 if (ret >= 0) { 158 if (ret == maxlen) 159 dst[ret - 1] = '\0'; 160 else 161 /* 162 * Include the terminating null byte. In this case it 163 * was copied by strncpy_from_user but not accounted 164 * for in ret. 165 */ 166 ret++; 167 *(u32 *)dest = make_data_loc(ret, (void *)dst - base); 168 } else 169 *(u32 *)dest = make_data_loc(0, (void *)dst - base); 170 171 return ret; 172} 173 174static nokprobe_inline int 175fetch_store_string_user(unsigned long addr, void *dest, void *base) 176{ 177 return fetch_store_string(addr, dest, base); 178} 179 180/* Return the length of string -- including null terminal byte */ 181static nokprobe_inline int 182fetch_store_strlen(unsigned long addr) 183{ 184 int len; 185 void __user *vaddr = (void __force __user *) addr; 186 187 if (addr == FETCH_TOKEN_COMM) 188 len = strlen(current->comm) + 1; 189 else 190 len = strnlen_user(vaddr, MAX_STRING_SIZE); 191 192 return (len > MAX_STRING_SIZE) ? 0 : len; 193} 194 195static nokprobe_inline int 196fetch_store_strlen_user(unsigned long addr) 197{ 198 return fetch_store_strlen(addr); 199} 200 201static unsigned long translate_user_vaddr(unsigned long file_offset) 202{ 203 unsigned long base_addr; 204 struct uprobe_dispatch_data *udd; 205 206 udd = (void *) current->utask->vaddr; 207 208 base_addr = udd->bp_addr - udd->tu->offset; 209 return base_addr + file_offset; 210} 211 212/* Note that we don't verify it, since the code does not come from user space */ 213static int 214process_fetch_insn(struct fetch_insn *code, void *rec, void *edata, 215 void *dest, void *base) 216{ 217 struct pt_regs *regs = rec; 218 unsigned long val; 219 int ret; 220 221 /* 1st stage: get value from context */ 222 switch (code->op) { 223 case FETCH_OP_REG: 224 val = regs_get_register(regs, code->param); 225 break; 226 case FETCH_OP_STACK: 227 val = get_user_stack_nth(regs, code->param); 228 break; 229 case FETCH_OP_STACKP: 230 val = user_stack_pointer(regs); 231 break; 232 case FETCH_OP_RETVAL: 233 val = regs_return_value(regs); 234 break; 235 case FETCH_OP_COMM: 236 val = FETCH_TOKEN_COMM; 237 break; 238 case FETCH_OP_FOFFS: 239 val = translate_user_vaddr(code->immediate); 240 break; 241 default: 242 ret = process_common_fetch_insn(code, &val); 243 if (ret < 0) 244 return ret; 245 } 246 code++; 247 248 return process_fetch_insn_bottom(code, val, dest, base); 249} 250NOKPROBE_SYMBOL(process_fetch_insn) 251 252static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter) 253{ 254 rwlock_init(&filter->rwlock); 255 filter->nr_systemwide = 0; 256 INIT_LIST_HEAD(&filter->perf_events); 257} 258 259static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter) 260{ 261 return !filter->nr_systemwide && list_empty(&filter->perf_events); 262} 263 264static inline bool is_ret_probe(struct trace_uprobe *tu) 265{ 266 return tu->consumer.ret_handler != NULL; 267} 268 269static bool trace_uprobe_is_busy(struct dyn_event *ev) 270{ 271 struct trace_uprobe *tu = to_trace_uprobe(ev); 272 273 return trace_probe_is_enabled(&tu->tp); 274} 275 276static bool trace_uprobe_match_command_head(struct trace_uprobe *tu, 277 int argc, const char **argv) 278{ 279 char buf[MAX_ARGSTR_LEN + 1]; 280 int len; 281 282 if (!argc) 283 return true; 284 285 len = strlen(tu->filename); 286 if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':') 287 return false; 288 289 if (tu->ref_ctr_offset == 0) 290 snprintf(buf, sizeof(buf), "0x%0*lx", 291 (int)(sizeof(void *) * 2), tu->offset); 292 else 293 snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)", 294 (int)(sizeof(void *) * 2), tu->offset, 295 tu->ref_ctr_offset); 296 if (strcmp(buf, &argv[0][len + 1])) 297 return false; 298 299 argc--; argv++; 300 301 return trace_probe_match_command_args(&tu->tp, argc, argv); 302} 303 304static bool trace_uprobe_match(const char *system, const char *event, 305 int argc, const char **argv, struct dyn_event *ev) 306{ 307 struct trace_uprobe *tu = to_trace_uprobe(ev); 308 309 return (event[0] == '\0' || 310 strcmp(trace_probe_name(&tu->tp), event) == 0) && 311 (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) && 312 trace_uprobe_match_command_head(tu, argc, argv); 313} 314 315static nokprobe_inline struct trace_uprobe * 316trace_uprobe_primary_from_call(struct trace_event_call *call) 317{ 318 struct trace_probe *tp; 319 320 tp = trace_probe_primary_from_call(call); 321 if (WARN_ON_ONCE(!tp)) 322 return NULL; 323 324 return container_of(tp, struct trace_uprobe, tp); 325} 326 327/* 328 * Allocate new trace_uprobe and initialize it (including uprobes). 329 */ 330static struct trace_uprobe * 331alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret) 332{ 333 struct trace_uprobe *tu; 334 int ret; 335 336 tu = kzalloc(struct_size(tu, tp.args, nargs), GFP_KERNEL); 337 if (!tu) 338 return ERR_PTR(-ENOMEM); 339 340 ret = trace_probe_init(&tu->tp, event, group, true, nargs); 341 if (ret < 0) 342 goto error; 343 344 dyn_event_init(&tu->devent, &trace_uprobe_ops); 345 tu->consumer.handler = uprobe_dispatcher; 346 if (is_ret) 347 tu->consumer.ret_handler = uretprobe_dispatcher; 348 init_trace_uprobe_filter(tu->tp.event->filter); 349 return tu; 350 351error: 352 kfree(tu); 353 354 return ERR_PTR(ret); 355} 356 357static void free_trace_uprobe(struct trace_uprobe *tu) 358{ 359 if (!tu) 360 return; 361 362 path_put(&tu->path); 363 trace_probe_cleanup(&tu->tp); 364 kfree(tu->filename); 365 kfree(tu); 366} 367 368static struct trace_uprobe *find_probe_event(const char *event, const char *group) 369{ 370 struct dyn_event *pos; 371 struct trace_uprobe *tu; 372 373 for_each_trace_uprobe(tu, pos) 374 if (strcmp(trace_probe_name(&tu->tp), event) == 0 && 375 strcmp(trace_probe_group_name(&tu->tp), group) == 0) 376 return tu; 377 378 return NULL; 379} 380 381/* Unregister a trace_uprobe and probe_event */ 382static int unregister_trace_uprobe(struct trace_uprobe *tu) 383{ 384 int ret; 385 386 if (trace_probe_has_sibling(&tu->tp)) 387 goto unreg; 388 389 /* If there's a reference to the dynamic event */ 390 if (trace_event_dyn_busy(trace_probe_event_call(&tu->tp))) 391 return -EBUSY; 392 393 ret = unregister_uprobe_event(tu); 394 if (ret) 395 return ret; 396 397unreg: 398 dyn_event_remove(&tu->devent); 399 trace_probe_unlink(&tu->tp); 400 free_trace_uprobe(tu); 401 return 0; 402} 403 404static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig, 405 struct trace_uprobe *comp) 406{ 407 struct trace_probe_event *tpe = orig->tp.event; 408 struct inode *comp_inode = d_real_inode(comp->path.dentry); 409 int i; 410 411 list_for_each_entry(orig, &tpe->probes, tp.list) { 412 if (comp_inode != d_real_inode(orig->path.dentry) || 413 comp->offset != orig->offset) 414 continue; 415 416 /* 417 * trace_probe_compare_arg_type() ensured that nr_args and 418 * each argument name and type are same. Let's compare comm. 419 */ 420 for (i = 0; i < orig->tp.nr_args; i++) { 421 if (strcmp(orig->tp.args[i].comm, 422 comp->tp.args[i].comm)) 423 break; 424 } 425 426 if (i == orig->tp.nr_args) 427 return true; 428 } 429 430 return false; 431} 432 433static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to) 434{ 435 int ret; 436 437 ret = trace_probe_compare_arg_type(&tu->tp, &to->tp); 438 if (ret) { 439 /* Note that argument starts index = 2 */ 440 trace_probe_log_set_index(ret + 1); 441 trace_probe_log_err(0, DIFF_ARG_TYPE); 442 return -EEXIST; 443 } 444 if (trace_uprobe_has_same_uprobe(to, tu)) { 445 trace_probe_log_set_index(0); 446 trace_probe_log_err(0, SAME_PROBE); 447 return -EEXIST; 448 } 449 450 /* Append to existing event */ 451 ret = trace_probe_append(&tu->tp, &to->tp); 452 if (!ret) 453 dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp)); 454 455 return ret; 456} 457 458/* 459 * Uprobe with multiple reference counter is not allowed. i.e. 460 * If inode and offset matches, reference counter offset *must* 461 * match as well. Though, there is one exception: If user is 462 * replacing old trace_uprobe with new one(same group/event), 463 * then we allow same uprobe with new reference counter as far 464 * as the new one does not conflict with any other existing 465 * ones. 466 */ 467static int validate_ref_ctr_offset(struct trace_uprobe *new) 468{ 469 struct dyn_event *pos; 470 struct trace_uprobe *tmp; 471 struct inode *new_inode = d_real_inode(new->path.dentry); 472 473 for_each_trace_uprobe(tmp, pos) { 474 if (new_inode == d_real_inode(tmp->path.dentry) && 475 new->offset == tmp->offset && 476 new->ref_ctr_offset != tmp->ref_ctr_offset) { 477 pr_warn("Reference counter offset mismatch."); 478 return -EINVAL; 479 } 480 } 481 return 0; 482} 483 484/* Register a trace_uprobe and probe_event */ 485static int register_trace_uprobe(struct trace_uprobe *tu) 486{ 487 struct trace_uprobe *old_tu; 488 int ret; 489 490 mutex_lock(&event_mutex); 491 492 ret = validate_ref_ctr_offset(tu); 493 if (ret) 494 goto end; 495 496 /* register as an event */ 497 old_tu = find_probe_event(trace_probe_name(&tu->tp), 498 trace_probe_group_name(&tu->tp)); 499 if (old_tu) { 500 if (is_ret_probe(tu) != is_ret_probe(old_tu)) { 501 trace_probe_log_set_index(0); 502 trace_probe_log_err(0, DIFF_PROBE_TYPE); 503 ret = -EEXIST; 504 } else { 505 ret = append_trace_uprobe(tu, old_tu); 506 } 507 goto end; 508 } 509 510 ret = register_uprobe_event(tu); 511 if (ret) { 512 if (ret == -EEXIST) { 513 trace_probe_log_set_index(0); 514 trace_probe_log_err(0, EVENT_EXIST); 515 } else 516 pr_warn("Failed to register probe event(%d)\n", ret); 517 goto end; 518 } 519 520 dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp)); 521 522end: 523 mutex_unlock(&event_mutex); 524 525 return ret; 526} 527 528/* 529 * Argument syntax: 530 * - Add uprobe: p|r[:[GRP/][EVENT]] PATH:OFFSET[%return][(REF)] [FETCHARGS] 531 */ 532static int __trace_uprobe_create(int argc, const char **argv) 533{ 534 struct trace_uprobe *tu; 535 const char *event = NULL, *group = UPROBE_EVENT_SYSTEM; 536 char *arg, *filename, *rctr, *rctr_end, *tmp; 537 char buf[MAX_EVENT_NAME_LEN]; 538 char gbuf[MAX_EVENT_NAME_LEN]; 539 enum probe_print_type ptype; 540 struct path path; 541 unsigned long offset, ref_ctr_offset; 542 bool is_return = false; 543 int i, ret; 544 545 ref_ctr_offset = 0; 546 547 switch (argv[0][0]) { 548 case 'r': 549 is_return = true; 550 break; 551 case 'p': 552 break; 553 default: 554 return -ECANCELED; 555 } 556 557 if (argc < 2) 558 return -ECANCELED; 559 560 if (argv[0][1] == ':') 561 event = &argv[0][2]; 562 563 if (!strchr(argv[1], '/')) 564 return -ECANCELED; 565 566 filename = kstrdup(argv[1], GFP_KERNEL); 567 if (!filename) 568 return -ENOMEM; 569 570 /* Find the last occurrence, in case the path contains ':' too. */ 571 arg = strrchr(filename, ':'); 572 if (!arg || !isdigit(arg[1])) { 573 kfree(filename); 574 return -ECANCELED; 575 } 576 577 trace_probe_log_init("trace_uprobe", argc, argv); 578 trace_probe_log_set_index(1); /* filename is the 2nd argument */ 579 580 *arg++ = '\0'; 581 ret = kern_path(filename, LOOKUP_FOLLOW, &path); 582 if (ret) { 583 trace_probe_log_err(0, FILE_NOT_FOUND); 584 kfree(filename); 585 trace_probe_log_clear(); 586 return ret; 587 } 588 if (!d_is_reg(path.dentry)) { 589 trace_probe_log_err(0, NO_REGULAR_FILE); 590 ret = -EINVAL; 591 goto fail_address_parse; 592 } 593 594 /* Parse reference counter offset if specified. */ 595 rctr = strchr(arg, '('); 596 if (rctr) { 597 rctr_end = strchr(rctr, ')'); 598 if (!rctr_end) { 599 ret = -EINVAL; 600 rctr_end = rctr + strlen(rctr); 601 trace_probe_log_err(rctr_end - filename, 602 REFCNT_OPEN_BRACE); 603 goto fail_address_parse; 604 } else if (rctr_end[1] != '\0') { 605 ret = -EINVAL; 606 trace_probe_log_err(rctr_end + 1 - filename, 607 BAD_REFCNT_SUFFIX); 608 goto fail_address_parse; 609 } 610 611 *rctr++ = '\0'; 612 *rctr_end = '\0'; 613 ret = kstrtoul(rctr, 0, &ref_ctr_offset); 614 if (ret) { 615 trace_probe_log_err(rctr - filename, BAD_REFCNT); 616 goto fail_address_parse; 617 } 618 } 619 620 /* Check if there is %return suffix */ 621 tmp = strchr(arg, '%'); 622 if (tmp) { 623 if (!strcmp(tmp, "%return")) { 624 *tmp = '\0'; 625 is_return = true; 626 } else { 627 trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX); 628 ret = -EINVAL; 629 goto fail_address_parse; 630 } 631 } 632 633 /* Parse uprobe offset. */ 634 ret = kstrtoul(arg, 0, &offset); 635 if (ret) { 636 trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS); 637 goto fail_address_parse; 638 } 639 640 /* setup a probe */ 641 trace_probe_log_set_index(0); 642 if (event) { 643 ret = traceprobe_parse_event_name(&event, &group, gbuf, 644 event - argv[0]); 645 if (ret) 646 goto fail_address_parse; 647 } 648 649 if (!event) { 650 char *tail; 651 char *ptr; 652 653 tail = kstrdup(kbasename(filename), GFP_KERNEL); 654 if (!tail) { 655 ret = -ENOMEM; 656 goto fail_address_parse; 657 } 658 659 ptr = strpbrk(tail, ".-_"); 660 if (ptr) 661 *ptr = '\0'; 662 663 snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset); 664 event = buf; 665 kfree(tail); 666 } 667 668 argc -= 2; 669 argv += 2; 670 671 tu = alloc_trace_uprobe(group, event, argc, is_return); 672 if (IS_ERR(tu)) { 673 ret = PTR_ERR(tu); 674 /* This must return -ENOMEM otherwise there is a bug */ 675 WARN_ON_ONCE(ret != -ENOMEM); 676 goto fail_address_parse; 677 } 678 tu->offset = offset; 679 tu->ref_ctr_offset = ref_ctr_offset; 680 tu->path = path; 681 tu->filename = filename; 682 683 /* parse arguments */ 684 for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) { 685 struct traceprobe_parse_context ctx = { 686 .flags = (is_return ? TPARG_FL_RETURN : 0) | TPARG_FL_USER, 687 }; 688 689 trace_probe_log_set_index(i + 2); 690 ret = traceprobe_parse_probe_arg(&tu->tp, i, argv[i], &ctx); 691 traceprobe_finish_parse(&ctx); 692 if (ret) 693 goto error; 694 } 695 696 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; 697 ret = traceprobe_set_print_fmt(&tu->tp, ptype); 698 if (ret < 0) 699 goto error; 700 701 ret = register_trace_uprobe(tu); 702 if (!ret) 703 goto out; 704 705error: 706 free_trace_uprobe(tu); 707out: 708 trace_probe_log_clear(); 709 return ret; 710 711fail_address_parse: 712 trace_probe_log_clear(); 713 path_put(&path); 714 kfree(filename); 715 716 return ret; 717} 718 719int trace_uprobe_create(const char *raw_command) 720{ 721 return trace_probe_create(raw_command, __trace_uprobe_create); 722} 723 724static int create_or_delete_trace_uprobe(const char *raw_command) 725{ 726 int ret; 727 728 if (raw_command[0] == '-') 729 return dyn_event_release(raw_command, &trace_uprobe_ops); 730 731 ret = trace_uprobe_create(raw_command); 732 return ret == -ECANCELED ? -EINVAL : ret; 733} 734 735static int trace_uprobe_release(struct dyn_event *ev) 736{ 737 struct trace_uprobe *tu = to_trace_uprobe(ev); 738 739 return unregister_trace_uprobe(tu); 740} 741 742/* Probes listing interfaces */ 743static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev) 744{ 745 struct trace_uprobe *tu = to_trace_uprobe(ev); 746 char c = is_ret_probe(tu) ? 'r' : 'p'; 747 int i; 748 749 seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp), 750 trace_probe_name(&tu->tp), tu->filename, 751 (int)(sizeof(void *) * 2), tu->offset); 752 753 if (tu->ref_ctr_offset) 754 seq_printf(m, "(0x%lx)", tu->ref_ctr_offset); 755 756 for (i = 0; i < tu->tp.nr_args; i++) 757 seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm); 758 759 seq_putc(m, '\n'); 760 return 0; 761} 762 763static int probes_seq_show(struct seq_file *m, void *v) 764{ 765 struct dyn_event *ev = v; 766 767 if (!is_trace_uprobe(ev)) 768 return 0; 769 770 return trace_uprobe_show(m, ev); 771} 772 773static const struct seq_operations probes_seq_op = { 774 .start = dyn_event_seq_start, 775 .next = dyn_event_seq_next, 776 .stop = dyn_event_seq_stop, 777 .show = probes_seq_show 778}; 779 780static int probes_open(struct inode *inode, struct file *file) 781{ 782 int ret; 783 784 ret = security_locked_down(LOCKDOWN_TRACEFS); 785 if (ret) 786 return ret; 787 788 if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { 789 ret = dyn_events_release_all(&trace_uprobe_ops); 790 if (ret) 791 return ret; 792 } 793 794 return seq_open(file, &probes_seq_op); 795} 796 797static ssize_t probes_write(struct file *file, const char __user *buffer, 798 size_t count, loff_t *ppos) 799{ 800 return trace_parse_run_command(file, buffer, count, ppos, 801 create_or_delete_trace_uprobe); 802} 803 804static const struct file_operations uprobe_events_ops = { 805 .owner = THIS_MODULE, 806 .open = probes_open, 807 .read = seq_read, 808 .llseek = seq_lseek, 809 .release = seq_release, 810 .write = probes_write, 811}; 812 813/* Probes profiling interfaces */ 814static int probes_profile_seq_show(struct seq_file *m, void *v) 815{ 816 struct dyn_event *ev = v; 817 struct trace_uprobe *tu; 818 819 if (!is_trace_uprobe(ev)) 820 return 0; 821 822 tu = to_trace_uprobe(ev); 823 seq_printf(m, " %s %-44s %15lu\n", tu->filename, 824 trace_probe_name(&tu->tp), tu->nhit); 825 return 0; 826} 827 828static const struct seq_operations profile_seq_op = { 829 .start = dyn_event_seq_start, 830 .next = dyn_event_seq_next, 831 .stop = dyn_event_seq_stop, 832 .show = probes_profile_seq_show 833}; 834 835static int profile_open(struct inode *inode, struct file *file) 836{ 837 int ret; 838 839 ret = security_locked_down(LOCKDOWN_TRACEFS); 840 if (ret) 841 return ret; 842 843 return seq_open(file, &profile_seq_op); 844} 845 846static const struct file_operations uprobe_profile_ops = { 847 .owner = THIS_MODULE, 848 .open = profile_open, 849 .read = seq_read, 850 .llseek = seq_lseek, 851 .release = seq_release, 852}; 853 854struct uprobe_cpu_buffer { 855 struct mutex mutex; 856 void *buf; 857 int dsize; 858}; 859static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer; 860static int uprobe_buffer_refcnt; 861 862static 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 883err: 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 894static 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 909static 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 925static 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 942static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb) 943{ 944 if (!ucb) 945 return; 946 mutex_unlock(&ucb->mutex); 947} 948 949static struct uprobe_cpu_buffer *prepare_uprobe_buffer(struct trace_uprobe *tu, 950 struct pt_regs *regs, 951 struct uprobe_cpu_buffer **ucbp) 952{ 953 struct uprobe_cpu_buffer *ucb; 954 int dsize, esize; 955 956 if (*ucbp) 957 return *ucbp; 958 959 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 960 dsize = __get_data_size(&tu->tp, regs, NULL); 961 962 ucb = uprobe_buffer_get(); 963 ucb->dsize = tu->tp.size + dsize; 964 965 store_trace_args(ucb->buf, &tu->tp, regs, NULL, esize, dsize); 966 967 *ucbp = ucb; 968 return ucb; 969} 970 971static void __uprobe_trace_func(struct trace_uprobe *tu, 972 unsigned long func, struct pt_regs *regs, 973 struct uprobe_cpu_buffer *ucb, 974 struct trace_event_file *trace_file) 975{ 976 struct uprobe_trace_entry_head *entry; 977 struct trace_event_buffer fbuffer; 978 void *data; 979 int size, esize; 980 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 981 982 WARN_ON(call != trace_file->event_call); 983 984 if (WARN_ON_ONCE(ucb->dsize > PAGE_SIZE)) 985 return; 986 987 if (trace_trigger_soft_disabled(trace_file)) 988 return; 989 990 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 991 size = esize + ucb->dsize; 992 entry = trace_event_buffer_reserve(&fbuffer, trace_file, size); 993 if (!entry) 994 return; 995 996 if (is_ret_probe(tu)) { 997 entry->vaddr[0] = func; 998 entry->vaddr[1] = instruction_pointer(regs); 999 data = DATAOF_TRACE_ENTRY(entry, true); 1000 } else { 1001 entry->vaddr[0] = instruction_pointer(regs); 1002 data = DATAOF_TRACE_ENTRY(entry, false); 1003 } 1004 1005 memcpy(data, ucb->buf, ucb->dsize); 1006 1007 trace_event_buffer_commit(&fbuffer); 1008} 1009 1010/* uprobe handler */ 1011static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs, 1012 struct uprobe_cpu_buffer **ucbp) 1013{ 1014 struct event_file_link *link; 1015 struct uprobe_cpu_buffer *ucb; 1016 1017 if (is_ret_probe(tu)) 1018 return 0; 1019 1020 ucb = prepare_uprobe_buffer(tu, regs, ucbp); 1021 1022 rcu_read_lock(); 1023 trace_probe_for_each_link_rcu(link, &tu->tp) 1024 __uprobe_trace_func(tu, 0, regs, ucb, link->file); 1025 rcu_read_unlock(); 1026 1027 return 0; 1028} 1029 1030static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func, 1031 struct pt_regs *regs, 1032 struct uprobe_cpu_buffer **ucbp) 1033{ 1034 struct event_file_link *link; 1035 struct uprobe_cpu_buffer *ucb; 1036 1037 ucb = prepare_uprobe_buffer(tu, regs, ucbp); 1038 1039 rcu_read_lock(); 1040 trace_probe_for_each_link_rcu(link, &tu->tp) 1041 __uprobe_trace_func(tu, func, regs, ucb, link->file); 1042 rcu_read_unlock(); 1043} 1044 1045/* Event entry printers */ 1046static enum print_line_t 1047print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) 1048{ 1049 struct uprobe_trace_entry_head *entry; 1050 struct trace_seq *s = &iter->seq; 1051 struct trace_uprobe *tu; 1052 u8 *data; 1053 1054 entry = (struct uprobe_trace_entry_head *)iter->ent; 1055 tu = trace_uprobe_primary_from_call( 1056 container_of(event, struct trace_event_call, event)); 1057 if (unlikely(!tu)) 1058 goto out; 1059 1060 if (is_ret_probe(tu)) { 1061 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)", 1062 trace_probe_name(&tu->tp), 1063 entry->vaddr[1], entry->vaddr[0]); 1064 data = DATAOF_TRACE_ENTRY(entry, true); 1065 } else { 1066 trace_seq_printf(s, "%s: (0x%lx)", 1067 trace_probe_name(&tu->tp), 1068 entry->vaddr[0]); 1069 data = DATAOF_TRACE_ENTRY(entry, false); 1070 } 1071 1072 if (trace_probe_print_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0) 1073 goto out; 1074 1075 trace_seq_putc(s, '\n'); 1076 1077 out: 1078 return trace_handle_return(s); 1079} 1080 1081typedef bool (*filter_func_t)(struct uprobe_consumer *self, 1082 enum uprobe_filter_ctx ctx, 1083 struct mm_struct *mm); 1084 1085static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter) 1086{ 1087 int ret; 1088 1089 tu->consumer.filter = filter; 1090 tu->inode = d_real_inode(tu->path.dentry); 1091 1092 if (tu->ref_ctr_offset) 1093 ret = uprobe_register_refctr(tu->inode, tu->offset, 1094 tu->ref_ctr_offset, &tu->consumer); 1095 else 1096 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer); 1097 1098 if (ret) 1099 tu->inode = NULL; 1100 1101 return ret; 1102} 1103 1104static void __probe_event_disable(struct trace_probe *tp) 1105{ 1106 struct trace_uprobe *tu; 1107 1108 tu = container_of(tp, struct trace_uprobe, tp); 1109 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter)); 1110 1111 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1112 if (!tu->inode) 1113 continue; 1114 1115 uprobe_unregister(tu->inode, tu->offset, &tu->consumer); 1116 tu->inode = NULL; 1117 } 1118} 1119 1120static int probe_event_enable(struct trace_event_call *call, 1121 struct trace_event_file *file, filter_func_t filter) 1122{ 1123 struct trace_probe *tp; 1124 struct trace_uprobe *tu; 1125 bool enabled; 1126 int ret; 1127 1128 tp = trace_probe_primary_from_call(call); 1129 if (WARN_ON_ONCE(!tp)) 1130 return -ENODEV; 1131 enabled = trace_probe_is_enabled(tp); 1132 1133 /* This may also change "enabled" state */ 1134 if (file) { 1135 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE)) 1136 return -EINTR; 1137 1138 ret = trace_probe_add_file(tp, file); 1139 if (ret < 0) 1140 return ret; 1141 } else { 1142 if (trace_probe_test_flag(tp, TP_FLAG_TRACE)) 1143 return -EINTR; 1144 1145 trace_probe_set_flag(tp, TP_FLAG_PROFILE); 1146 } 1147 1148 tu = container_of(tp, struct trace_uprobe, tp); 1149 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter)); 1150 1151 if (enabled) 1152 return 0; 1153 1154 ret = uprobe_buffer_enable(); 1155 if (ret) 1156 goto err_flags; 1157 1158 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1159 ret = trace_uprobe_enable(tu, filter); 1160 if (ret) { 1161 __probe_event_disable(tp); 1162 goto err_buffer; 1163 } 1164 } 1165 1166 return 0; 1167 1168 err_buffer: 1169 uprobe_buffer_disable(); 1170 1171 err_flags: 1172 if (file) 1173 trace_probe_remove_file(tp, file); 1174 else 1175 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 1176 1177 return ret; 1178} 1179 1180static void probe_event_disable(struct trace_event_call *call, 1181 struct trace_event_file *file) 1182{ 1183 struct trace_probe *tp; 1184 1185 tp = trace_probe_primary_from_call(call); 1186 if (WARN_ON_ONCE(!tp)) 1187 return; 1188 1189 if (!trace_probe_is_enabled(tp)) 1190 return; 1191 1192 if (file) { 1193 if (trace_probe_remove_file(tp, file) < 0) 1194 return; 1195 1196 if (trace_probe_is_enabled(tp)) 1197 return; 1198 } else 1199 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 1200 1201 __probe_event_disable(tp); 1202 uprobe_buffer_disable(); 1203} 1204 1205static int uprobe_event_define_fields(struct trace_event_call *event_call) 1206{ 1207 int ret, size; 1208 struct uprobe_trace_entry_head field; 1209 struct trace_uprobe *tu; 1210 1211 tu = trace_uprobe_primary_from_call(event_call); 1212 if (unlikely(!tu)) 1213 return -ENODEV; 1214 1215 if (is_ret_probe(tu)) { 1216 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0); 1217 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0); 1218 size = SIZEOF_TRACE_ENTRY(true); 1219 } else { 1220 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0); 1221 size = SIZEOF_TRACE_ENTRY(false); 1222 } 1223 1224 return traceprobe_define_arg_fields(event_call, size, &tu->tp); 1225} 1226 1227#ifdef CONFIG_PERF_EVENTS 1228static bool 1229__uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm) 1230{ 1231 struct perf_event *event; 1232 1233 list_for_each_entry(event, &filter->perf_events, hw.tp_list) { 1234 if (event->hw.target->mm == mm) 1235 return true; 1236 } 1237 1238 return false; 1239} 1240 1241static inline bool 1242trace_uprobe_filter_event(struct trace_uprobe_filter *filter, 1243 struct perf_event *event) 1244{ 1245 return __uprobe_perf_filter(filter, event->hw.target->mm); 1246} 1247 1248static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter, 1249 struct perf_event *event) 1250{ 1251 bool done; 1252 1253 write_lock(&filter->rwlock); 1254 if (event->hw.target) { 1255 list_del(&event->hw.tp_list); 1256 done = filter->nr_systemwide || 1257 (event->hw.target->flags & PF_EXITING) || 1258 trace_uprobe_filter_event(filter, event); 1259 } else { 1260 filter->nr_systemwide--; 1261 done = filter->nr_systemwide; 1262 } 1263 write_unlock(&filter->rwlock); 1264 1265 return done; 1266} 1267 1268/* This returns true if the filter always covers target mm */ 1269static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter, 1270 struct perf_event *event) 1271{ 1272 bool done; 1273 1274 write_lock(&filter->rwlock); 1275 if (event->hw.target) { 1276 /* 1277 * event->parent != NULL means copy_process(), we can avoid 1278 * uprobe_apply(). current->mm must be probed and we can rely 1279 * on dup_mmap() which preserves the already installed bp's. 1280 * 1281 * attr.enable_on_exec means that exec/mmap will install the 1282 * breakpoints we need. 1283 */ 1284 done = filter->nr_systemwide || 1285 event->parent || event->attr.enable_on_exec || 1286 trace_uprobe_filter_event(filter, event); 1287 list_add(&event->hw.tp_list, &filter->perf_events); 1288 } else { 1289 done = filter->nr_systemwide; 1290 filter->nr_systemwide++; 1291 } 1292 write_unlock(&filter->rwlock); 1293 1294 return done; 1295} 1296 1297static int uprobe_perf_close(struct trace_event_call *call, 1298 struct perf_event *event) 1299{ 1300 struct trace_probe *tp; 1301 struct trace_uprobe *tu; 1302 int ret = 0; 1303 1304 tp = trace_probe_primary_from_call(call); 1305 if (WARN_ON_ONCE(!tp)) 1306 return -ENODEV; 1307 1308 tu = container_of(tp, struct trace_uprobe, tp); 1309 if (trace_uprobe_filter_remove(tu->tp.event->filter, event)) 1310 return 0; 1311 1312 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1313 ret = uprobe_apply(tu->inode, tu->offset, &tu->consumer, false); 1314 if (ret) 1315 break; 1316 } 1317 1318 return ret; 1319} 1320 1321static int uprobe_perf_open(struct trace_event_call *call, 1322 struct perf_event *event) 1323{ 1324 struct trace_probe *tp; 1325 struct trace_uprobe *tu; 1326 int err = 0; 1327 1328 tp = trace_probe_primary_from_call(call); 1329 if (WARN_ON_ONCE(!tp)) 1330 return -ENODEV; 1331 1332 tu = container_of(tp, struct trace_uprobe, tp); 1333 if (trace_uprobe_filter_add(tu->tp.event->filter, event)) 1334 return 0; 1335 1336 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1337 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true); 1338 if (err) { 1339 uprobe_perf_close(call, event); 1340 break; 1341 } 1342 } 1343 1344 return err; 1345} 1346 1347static bool uprobe_perf_filter(struct uprobe_consumer *uc, 1348 enum uprobe_filter_ctx ctx, struct mm_struct *mm) 1349{ 1350 struct trace_uprobe_filter *filter; 1351 struct trace_uprobe *tu; 1352 int ret; 1353 1354 tu = container_of(uc, struct trace_uprobe, consumer); 1355 filter = tu->tp.event->filter; 1356 1357 /* 1358 * speculative short-circuiting check to avoid unnecessarily taking 1359 * filter->rwlock below, if the uprobe has system-wide consumer 1360 */ 1361 if (READ_ONCE(filter->nr_systemwide)) 1362 return true; 1363 1364 read_lock(&filter->rwlock); 1365 ret = __uprobe_perf_filter(filter, mm); 1366 read_unlock(&filter->rwlock); 1367 1368 return ret; 1369} 1370 1371static void __uprobe_perf_func(struct trace_uprobe *tu, 1372 unsigned long func, struct pt_regs *regs, 1373 struct uprobe_cpu_buffer **ucbp) 1374{ 1375 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 1376 struct uprobe_trace_entry_head *entry; 1377 struct uprobe_cpu_buffer *ucb; 1378 struct hlist_head *head; 1379 void *data; 1380 int size, esize; 1381 int rctx; 1382 1383#ifdef CONFIG_BPF_EVENTS 1384 if (bpf_prog_array_valid(call)) { 1385 u32 ret; 1386 1387 ret = bpf_prog_run_array_uprobe(call->prog_array, regs, bpf_prog_run); 1388 if (!ret) 1389 return; 1390 } 1391#endif /* CONFIG_BPF_EVENTS */ 1392 1393 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1394 1395 ucb = prepare_uprobe_buffer(tu, regs, ucbp); 1396 size = esize + ucb->dsize; 1397 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32); 1398 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) 1399 return; 1400 1401 preempt_disable(); 1402 head = this_cpu_ptr(call->perf_events); 1403 if (hlist_empty(head)) 1404 goto out; 1405 1406 entry = perf_trace_buf_alloc(size, NULL, &rctx); 1407 if (!entry) 1408 goto out; 1409 1410 if (is_ret_probe(tu)) { 1411 entry->vaddr[0] = func; 1412 entry->vaddr[1] = instruction_pointer(regs); 1413 data = DATAOF_TRACE_ENTRY(entry, true); 1414 } else { 1415 entry->vaddr[0] = instruction_pointer(regs); 1416 data = DATAOF_TRACE_ENTRY(entry, false); 1417 } 1418 1419 memcpy(data, ucb->buf, ucb->dsize); 1420 1421 if (size - esize > ucb->dsize) 1422 memset(data + ucb->dsize, 0, size - esize - ucb->dsize); 1423 1424 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, 1425 head, NULL); 1426 out: 1427 preempt_enable(); 1428} 1429 1430/* uprobe profile handler */ 1431static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs, 1432 struct uprobe_cpu_buffer **ucbp) 1433{ 1434 if (!uprobe_perf_filter(&tu->consumer, 0, current->mm)) 1435 return UPROBE_HANDLER_REMOVE; 1436 1437 if (!is_ret_probe(tu)) 1438 __uprobe_perf_func(tu, 0, regs, ucbp); 1439 return 0; 1440} 1441 1442static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func, 1443 struct pt_regs *regs, 1444 struct uprobe_cpu_buffer **ucbp) 1445{ 1446 __uprobe_perf_func(tu, func, regs, ucbp); 1447} 1448 1449int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type, 1450 const char **filename, u64 *probe_offset, 1451 u64 *probe_addr, bool perf_type_tracepoint) 1452{ 1453 const char *pevent = trace_event_name(event->tp_event); 1454 const char *group = event->tp_event->class->system; 1455 struct trace_uprobe *tu; 1456 1457 if (perf_type_tracepoint) 1458 tu = find_probe_event(pevent, group); 1459 else 1460 tu = trace_uprobe_primary_from_call(event->tp_event); 1461 if (!tu) 1462 return -EINVAL; 1463 1464 *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE 1465 : BPF_FD_TYPE_UPROBE; 1466 *filename = tu->filename; 1467 *probe_offset = tu->offset; 1468 *probe_addr = 0; 1469 return 0; 1470} 1471#endif /* CONFIG_PERF_EVENTS */ 1472 1473static int 1474trace_uprobe_register(struct trace_event_call *event, enum trace_reg type, 1475 void *data) 1476{ 1477 struct trace_event_file *file = data; 1478 1479 switch (type) { 1480 case TRACE_REG_REGISTER: 1481 return probe_event_enable(event, file, NULL); 1482 1483 case TRACE_REG_UNREGISTER: 1484 probe_event_disable(event, file); 1485 return 0; 1486 1487#ifdef CONFIG_PERF_EVENTS 1488 case TRACE_REG_PERF_REGISTER: 1489 return probe_event_enable(event, NULL, uprobe_perf_filter); 1490 1491 case TRACE_REG_PERF_UNREGISTER: 1492 probe_event_disable(event, NULL); 1493 return 0; 1494 1495 case TRACE_REG_PERF_OPEN: 1496 return uprobe_perf_open(event, data); 1497 1498 case TRACE_REG_PERF_CLOSE: 1499 return uprobe_perf_close(event, data); 1500 1501#endif 1502 default: 1503 return 0; 1504 } 1505} 1506 1507static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) 1508{ 1509 struct trace_uprobe *tu; 1510 struct uprobe_dispatch_data udd; 1511 struct uprobe_cpu_buffer *ucb = NULL; 1512 int ret = 0; 1513 1514 tu = container_of(con, struct trace_uprobe, consumer); 1515 tu->nhit++; 1516 1517 udd.tu = tu; 1518 udd.bp_addr = instruction_pointer(regs); 1519 1520 current->utask->vaddr = (unsigned long) &udd; 1521 1522 if (WARN_ON_ONCE(!uprobe_cpu_buffer)) 1523 return 0; 1524 1525 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) 1526 ret |= uprobe_trace_func(tu, regs, &ucb); 1527 1528#ifdef CONFIG_PERF_EVENTS 1529 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) 1530 ret |= uprobe_perf_func(tu, regs, &ucb); 1531#endif 1532 uprobe_buffer_put(ucb); 1533 return ret; 1534} 1535 1536static int uretprobe_dispatcher(struct uprobe_consumer *con, 1537 unsigned long func, struct pt_regs *regs) 1538{ 1539 struct trace_uprobe *tu; 1540 struct uprobe_dispatch_data udd; 1541 struct uprobe_cpu_buffer *ucb = NULL; 1542 1543 tu = container_of(con, struct trace_uprobe, consumer); 1544 1545 udd.tu = tu; 1546 udd.bp_addr = func; 1547 1548 current->utask->vaddr = (unsigned long) &udd; 1549 1550 if (WARN_ON_ONCE(!uprobe_cpu_buffer)) 1551 return 0; 1552 1553 if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) 1554 uretprobe_trace_func(tu, func, regs, &ucb); 1555 1556#ifdef CONFIG_PERF_EVENTS 1557 if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) 1558 uretprobe_perf_func(tu, func, regs, &ucb); 1559#endif 1560 uprobe_buffer_put(ucb); 1561 return 0; 1562} 1563 1564static struct trace_event_functions uprobe_funcs = { 1565 .trace = print_uprobe_event 1566}; 1567 1568static struct trace_event_fields uprobe_fields_array[] = { 1569 { .type = TRACE_FUNCTION_TYPE, 1570 .define_fields = uprobe_event_define_fields }, 1571 {} 1572}; 1573 1574static inline void init_trace_event_call(struct trace_uprobe *tu) 1575{ 1576 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 1577 call->event.funcs = &uprobe_funcs; 1578 call->class->fields_array = uprobe_fields_array; 1579 1580 call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY; 1581 call->class->reg = trace_uprobe_register; 1582} 1583 1584static int register_uprobe_event(struct trace_uprobe *tu) 1585{ 1586 init_trace_event_call(tu); 1587 1588 return trace_probe_register_event_call(&tu->tp); 1589} 1590 1591static int unregister_uprobe_event(struct trace_uprobe *tu) 1592{ 1593 return trace_probe_unregister_event_call(&tu->tp); 1594} 1595 1596#ifdef CONFIG_PERF_EVENTS 1597struct trace_event_call * 1598create_local_trace_uprobe(char *name, unsigned long offs, 1599 unsigned long ref_ctr_offset, bool is_return) 1600{ 1601 enum probe_print_type ptype; 1602 struct trace_uprobe *tu; 1603 struct path path; 1604 int ret; 1605 1606 ret = kern_path(name, LOOKUP_FOLLOW, &path); 1607 if (ret) 1608 return ERR_PTR(ret); 1609 1610 if (!d_is_reg(path.dentry)) { 1611 path_put(&path); 1612 return ERR_PTR(-EINVAL); 1613 } 1614 1615 /* 1616 * local trace_kprobes are not added to dyn_event, so they are never 1617 * searched in find_trace_kprobe(). Therefore, there is no concern of 1618 * duplicated name "DUMMY_EVENT" here. 1619 */ 1620 tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0, 1621 is_return); 1622 1623 if (IS_ERR(tu)) { 1624 pr_info("Failed to allocate trace_uprobe.(%d)\n", 1625 (int)PTR_ERR(tu)); 1626 path_put(&path); 1627 return ERR_CAST(tu); 1628 } 1629 1630 tu->offset = offs; 1631 tu->path = path; 1632 tu->ref_ctr_offset = ref_ctr_offset; 1633 tu->filename = kstrdup(name, GFP_KERNEL); 1634 if (!tu->filename) { 1635 ret = -ENOMEM; 1636 goto error; 1637 } 1638 1639 init_trace_event_call(tu); 1640 1641 ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL; 1642 if (traceprobe_set_print_fmt(&tu->tp, ptype) < 0) { 1643 ret = -ENOMEM; 1644 goto error; 1645 } 1646 1647 return trace_probe_event_call(&tu->tp); 1648error: 1649 free_trace_uprobe(tu); 1650 return ERR_PTR(ret); 1651} 1652 1653void destroy_local_trace_uprobe(struct trace_event_call *event_call) 1654{ 1655 struct trace_uprobe *tu; 1656 1657 tu = trace_uprobe_primary_from_call(event_call); 1658 1659 free_trace_uprobe(tu); 1660} 1661#endif /* CONFIG_PERF_EVENTS */ 1662 1663/* Make a trace interface for controlling probe points */ 1664static __init int init_uprobe_trace(void) 1665{ 1666 int ret; 1667 1668 ret = dyn_event_register(&trace_uprobe_ops); 1669 if (ret) 1670 return ret; 1671 1672 ret = tracing_init_dentry(); 1673 if (ret) 1674 return 0; 1675 1676 trace_create_file("uprobe_events", TRACE_MODE_WRITE, NULL, 1677 NULL, &uprobe_events_ops); 1678 /* Profile interface */ 1679 trace_create_file("uprobe_profile", TRACE_MODE_READ, NULL, 1680 NULL, &uprobe_profile_ops); 1681 return 0; 1682} 1683 1684fs_initcall(init_uprobe_trace); 1685