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}; 858static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer; 859static int uprobe_buffer_refcnt; 860 861static int uprobe_buffer_init(void) 862{ 863 int cpu, err_cpu; 864 865 uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer); 866 if (uprobe_cpu_buffer == NULL) 867 return -ENOMEM; 868 869 for_each_possible_cpu(cpu) { 870 struct page *p = alloc_pages_node(cpu_to_node(cpu), 871 GFP_KERNEL, 0); 872 if (p == NULL) { 873 err_cpu = cpu; 874 goto err; 875 } 876 per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p); 877 mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex); 878 } 879 880 return 0; 881 882err: 883 for_each_possible_cpu(cpu) { 884 if (cpu == err_cpu) 885 break; 886 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf); 887 } 888 889 free_percpu(uprobe_cpu_buffer); 890 return -ENOMEM; 891} 892 893static int uprobe_buffer_enable(void) 894{ 895 int ret = 0; 896 897 BUG_ON(!mutex_is_locked(&event_mutex)); 898 899 if (uprobe_buffer_refcnt++ == 0) { 900 ret = uprobe_buffer_init(); 901 if (ret < 0) 902 uprobe_buffer_refcnt--; 903 } 904 905 return ret; 906} 907 908static void uprobe_buffer_disable(void) 909{ 910 int cpu; 911 912 BUG_ON(!mutex_is_locked(&event_mutex)); 913 914 if (--uprobe_buffer_refcnt == 0) { 915 for_each_possible_cpu(cpu) 916 free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, 917 cpu)->buf); 918 919 free_percpu(uprobe_cpu_buffer); 920 uprobe_cpu_buffer = NULL; 921 } 922} 923 924static struct uprobe_cpu_buffer *uprobe_buffer_get(void) 925{ 926 struct uprobe_cpu_buffer *ucb; 927 int cpu; 928 929 cpu = raw_smp_processor_id(); 930 ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu); 931 932 /* 933 * Use per-cpu buffers for fastest access, but we might migrate 934 * so the mutex makes sure we have sole access to it. 935 */ 936 mutex_lock(&ucb->mutex); 937 938 return ucb; 939} 940 941static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb) 942{ 943 mutex_unlock(&ucb->mutex); 944} 945 946static void __uprobe_trace_func(struct trace_uprobe *tu, 947 unsigned long func, struct pt_regs *regs, 948 struct uprobe_cpu_buffer *ucb, int dsize, 949 struct trace_event_file *trace_file) 950{ 951 struct uprobe_trace_entry_head *entry; 952 struct trace_event_buffer fbuffer; 953 void *data; 954 int size, esize; 955 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 956 957 WARN_ON(call != trace_file->event_call); 958 959 if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE)) 960 return; 961 962 if (trace_trigger_soft_disabled(trace_file)) 963 return; 964 965 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 966 size = esize + tu->tp.size + dsize; 967 entry = trace_event_buffer_reserve(&fbuffer, trace_file, size); 968 if (!entry) 969 return; 970 971 if (is_ret_probe(tu)) { 972 entry->vaddr[0] = func; 973 entry->vaddr[1] = instruction_pointer(regs); 974 data = DATAOF_TRACE_ENTRY(entry, true); 975 } else { 976 entry->vaddr[0] = instruction_pointer(regs); 977 data = DATAOF_TRACE_ENTRY(entry, false); 978 } 979 980 memcpy(data, ucb->buf, tu->tp.size + dsize); 981 982 trace_event_buffer_commit(&fbuffer); 983} 984 985/* uprobe handler */ 986static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs, 987 struct uprobe_cpu_buffer *ucb, int dsize) 988{ 989 struct event_file_link *link; 990 991 if (is_ret_probe(tu)) 992 return 0; 993 994 rcu_read_lock(); 995 trace_probe_for_each_link_rcu(link, &tu->tp) 996 __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file); 997 rcu_read_unlock(); 998 999 return 0; 1000} 1001 1002static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func, 1003 struct pt_regs *regs, 1004 struct uprobe_cpu_buffer *ucb, int dsize) 1005{ 1006 struct event_file_link *link; 1007 1008 rcu_read_lock(); 1009 trace_probe_for_each_link_rcu(link, &tu->tp) 1010 __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file); 1011 rcu_read_unlock(); 1012} 1013 1014/* Event entry printers */ 1015static enum print_line_t 1016print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) 1017{ 1018 struct uprobe_trace_entry_head *entry; 1019 struct trace_seq *s = &iter->seq; 1020 struct trace_uprobe *tu; 1021 u8 *data; 1022 1023 entry = (struct uprobe_trace_entry_head *)iter->ent; 1024 tu = trace_uprobe_primary_from_call( 1025 container_of(event, struct trace_event_call, event)); 1026 if (unlikely(!tu)) 1027 goto out; 1028 1029 if (is_ret_probe(tu)) { 1030 trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)", 1031 trace_probe_name(&tu->tp), 1032 entry->vaddr[1], entry->vaddr[0]); 1033 data = DATAOF_TRACE_ENTRY(entry, true); 1034 } else { 1035 trace_seq_printf(s, "%s: (0x%lx)", 1036 trace_probe_name(&tu->tp), 1037 entry->vaddr[0]); 1038 data = DATAOF_TRACE_ENTRY(entry, false); 1039 } 1040 1041 if (trace_probe_print_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0) 1042 goto out; 1043 1044 trace_seq_putc(s, '\n'); 1045 1046 out: 1047 return trace_handle_return(s); 1048} 1049 1050typedef bool (*filter_func_t)(struct uprobe_consumer *self, 1051 enum uprobe_filter_ctx ctx, 1052 struct mm_struct *mm); 1053 1054static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter) 1055{ 1056 int ret; 1057 1058 tu->consumer.filter = filter; 1059 tu->inode = d_real_inode(tu->path.dentry); 1060 1061 if (tu->ref_ctr_offset) 1062 ret = uprobe_register_refctr(tu->inode, tu->offset, 1063 tu->ref_ctr_offset, &tu->consumer); 1064 else 1065 ret = uprobe_register(tu->inode, tu->offset, &tu->consumer); 1066 1067 if (ret) 1068 tu->inode = NULL; 1069 1070 return ret; 1071} 1072 1073static void __probe_event_disable(struct trace_probe *tp) 1074{ 1075 struct trace_uprobe *tu; 1076 1077 tu = container_of(tp, struct trace_uprobe, tp); 1078 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter)); 1079 1080 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1081 if (!tu->inode) 1082 continue; 1083 1084 uprobe_unregister(tu->inode, tu->offset, &tu->consumer); 1085 tu->inode = NULL; 1086 } 1087} 1088 1089static int probe_event_enable(struct trace_event_call *call, 1090 struct trace_event_file *file, filter_func_t filter) 1091{ 1092 struct trace_probe *tp; 1093 struct trace_uprobe *tu; 1094 bool enabled; 1095 int ret; 1096 1097 tp = trace_probe_primary_from_call(call); 1098 if (WARN_ON_ONCE(!tp)) 1099 return -ENODEV; 1100 enabled = trace_probe_is_enabled(tp); 1101 1102 /* This may also change "enabled" state */ 1103 if (file) { 1104 if (trace_probe_test_flag(tp, TP_FLAG_PROFILE)) 1105 return -EINTR; 1106 1107 ret = trace_probe_add_file(tp, file); 1108 if (ret < 0) 1109 return ret; 1110 } else { 1111 if (trace_probe_test_flag(tp, TP_FLAG_TRACE)) 1112 return -EINTR; 1113 1114 trace_probe_set_flag(tp, TP_FLAG_PROFILE); 1115 } 1116 1117 tu = container_of(tp, struct trace_uprobe, tp); 1118 WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter)); 1119 1120 if (enabled) 1121 return 0; 1122 1123 ret = uprobe_buffer_enable(); 1124 if (ret) 1125 goto err_flags; 1126 1127 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1128 ret = trace_uprobe_enable(tu, filter); 1129 if (ret) { 1130 __probe_event_disable(tp); 1131 goto err_buffer; 1132 } 1133 } 1134 1135 return 0; 1136 1137 err_buffer: 1138 uprobe_buffer_disable(); 1139 1140 err_flags: 1141 if (file) 1142 trace_probe_remove_file(tp, file); 1143 else 1144 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 1145 1146 return ret; 1147} 1148 1149static void probe_event_disable(struct trace_event_call *call, 1150 struct trace_event_file *file) 1151{ 1152 struct trace_probe *tp; 1153 1154 tp = trace_probe_primary_from_call(call); 1155 if (WARN_ON_ONCE(!tp)) 1156 return; 1157 1158 if (!trace_probe_is_enabled(tp)) 1159 return; 1160 1161 if (file) { 1162 if (trace_probe_remove_file(tp, file) < 0) 1163 return; 1164 1165 if (trace_probe_is_enabled(tp)) 1166 return; 1167 } else 1168 trace_probe_clear_flag(tp, TP_FLAG_PROFILE); 1169 1170 __probe_event_disable(tp); 1171 uprobe_buffer_disable(); 1172} 1173 1174static int uprobe_event_define_fields(struct trace_event_call *event_call) 1175{ 1176 int ret, size; 1177 struct uprobe_trace_entry_head field; 1178 struct trace_uprobe *tu; 1179 1180 tu = trace_uprobe_primary_from_call(event_call); 1181 if (unlikely(!tu)) 1182 return -ENODEV; 1183 1184 if (is_ret_probe(tu)) { 1185 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0); 1186 DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0); 1187 size = SIZEOF_TRACE_ENTRY(true); 1188 } else { 1189 DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0); 1190 size = SIZEOF_TRACE_ENTRY(false); 1191 } 1192 1193 return traceprobe_define_arg_fields(event_call, size, &tu->tp); 1194} 1195 1196#ifdef CONFIG_PERF_EVENTS 1197static bool 1198__uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm) 1199{ 1200 struct perf_event *event; 1201 1202 if (filter->nr_systemwide) 1203 return true; 1204 1205 list_for_each_entry(event, &filter->perf_events, hw.tp_list) { 1206 if (event->hw.target->mm == mm) 1207 return true; 1208 } 1209 1210 return false; 1211} 1212 1213static inline bool 1214trace_uprobe_filter_event(struct trace_uprobe_filter *filter, 1215 struct perf_event *event) 1216{ 1217 return __uprobe_perf_filter(filter, event->hw.target->mm); 1218} 1219 1220static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter, 1221 struct perf_event *event) 1222{ 1223 bool done; 1224 1225 write_lock(&filter->rwlock); 1226 if (event->hw.target) { 1227 list_del(&event->hw.tp_list); 1228 done = filter->nr_systemwide || 1229 (event->hw.target->flags & PF_EXITING) || 1230 trace_uprobe_filter_event(filter, event); 1231 } else { 1232 filter->nr_systemwide--; 1233 done = filter->nr_systemwide; 1234 } 1235 write_unlock(&filter->rwlock); 1236 1237 return done; 1238} 1239 1240/* This returns true if the filter always covers target mm */ 1241static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter, 1242 struct perf_event *event) 1243{ 1244 bool done; 1245 1246 write_lock(&filter->rwlock); 1247 if (event->hw.target) { 1248 /* 1249 * event->parent != NULL means copy_process(), we can avoid 1250 * uprobe_apply(). current->mm must be probed and we can rely 1251 * on dup_mmap() which preserves the already installed bp's. 1252 * 1253 * attr.enable_on_exec means that exec/mmap will install the 1254 * breakpoints we need. 1255 */ 1256 done = filter->nr_systemwide || 1257 event->parent || event->attr.enable_on_exec || 1258 trace_uprobe_filter_event(filter, event); 1259 list_add(&event->hw.tp_list, &filter->perf_events); 1260 } else { 1261 done = filter->nr_systemwide; 1262 filter->nr_systemwide++; 1263 } 1264 write_unlock(&filter->rwlock); 1265 1266 return done; 1267} 1268 1269static int uprobe_perf_close(struct trace_event_call *call, 1270 struct perf_event *event) 1271{ 1272 struct trace_probe *tp; 1273 struct trace_uprobe *tu; 1274 int ret = 0; 1275 1276 tp = trace_probe_primary_from_call(call); 1277 if (WARN_ON_ONCE(!tp)) 1278 return -ENODEV; 1279 1280 tu = container_of(tp, struct trace_uprobe, tp); 1281 if (trace_uprobe_filter_remove(tu->tp.event->filter, event)) 1282 return 0; 1283 1284 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1285 ret = uprobe_apply(tu->inode, tu->offset, &tu->consumer, false); 1286 if (ret) 1287 break; 1288 } 1289 1290 return ret; 1291} 1292 1293static int uprobe_perf_open(struct trace_event_call *call, 1294 struct perf_event *event) 1295{ 1296 struct trace_probe *tp; 1297 struct trace_uprobe *tu; 1298 int err = 0; 1299 1300 tp = trace_probe_primary_from_call(call); 1301 if (WARN_ON_ONCE(!tp)) 1302 return -ENODEV; 1303 1304 tu = container_of(tp, struct trace_uprobe, tp); 1305 if (trace_uprobe_filter_add(tu->tp.event->filter, event)) 1306 return 0; 1307 1308 list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) { 1309 err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true); 1310 if (err) { 1311 uprobe_perf_close(call, event); 1312 break; 1313 } 1314 } 1315 1316 return err; 1317} 1318 1319static bool uprobe_perf_filter(struct uprobe_consumer *uc, 1320 enum uprobe_filter_ctx ctx, struct mm_struct *mm) 1321{ 1322 struct trace_uprobe_filter *filter; 1323 struct trace_uprobe *tu; 1324 int ret; 1325 1326 tu = container_of(uc, struct trace_uprobe, consumer); 1327 filter = tu->tp.event->filter; 1328 1329 read_lock(&filter->rwlock); 1330 ret = __uprobe_perf_filter(filter, mm); 1331 read_unlock(&filter->rwlock); 1332 1333 return ret; 1334} 1335 1336static void __uprobe_perf_func(struct trace_uprobe *tu, 1337 unsigned long func, struct pt_regs *regs, 1338 struct uprobe_cpu_buffer *ucb, int dsize) 1339{ 1340 struct trace_event_call *call = trace_probe_event_call(&tu->tp); 1341 struct uprobe_trace_entry_head *entry; 1342 struct hlist_head *head; 1343 void *data; 1344 int size, esize; 1345 int rctx; 1346 1347#ifdef CONFIG_BPF_EVENTS 1348 if (bpf_prog_array_valid(call)) { 1349 u32 ret; 1350 1351 ret = bpf_prog_run_array_uprobe(call->prog_array, regs, bpf_prog_run); 1352 if (!ret) 1353 return; 1354 } 1355#endif /* CONFIG_BPF_EVENTS */ 1356 1357 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1358 1359 size = esize + tu->tp.size + dsize; 1360 size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32); 1361 if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) 1362 return; 1363 1364 preempt_disable(); 1365 head = this_cpu_ptr(call->perf_events); 1366 if (hlist_empty(head)) 1367 goto out; 1368 1369 entry = perf_trace_buf_alloc(size, NULL, &rctx); 1370 if (!entry) 1371 goto out; 1372 1373 if (is_ret_probe(tu)) { 1374 entry->vaddr[0] = func; 1375 entry->vaddr[1] = instruction_pointer(regs); 1376 data = DATAOF_TRACE_ENTRY(entry, true); 1377 } else { 1378 entry->vaddr[0] = instruction_pointer(regs); 1379 data = DATAOF_TRACE_ENTRY(entry, false); 1380 } 1381 1382 memcpy(data, ucb->buf, tu->tp.size + dsize); 1383 1384 if (size - esize > tu->tp.size + dsize) { 1385 int len = tu->tp.size + dsize; 1386 1387 memset(data + len, 0, size - esize - len); 1388 } 1389 1390 perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, 1391 head, NULL); 1392 out: 1393 preempt_enable(); 1394} 1395 1396/* uprobe profile handler */ 1397static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs, 1398 struct uprobe_cpu_buffer *ucb, int dsize) 1399{ 1400 if (!uprobe_perf_filter(&tu->consumer, 0, current->mm)) 1401 return UPROBE_HANDLER_REMOVE; 1402 1403 if (!is_ret_probe(tu)) 1404 __uprobe_perf_func(tu, 0, regs, ucb, dsize); 1405 return 0; 1406} 1407 1408static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func, 1409 struct pt_regs *regs, 1410 struct uprobe_cpu_buffer *ucb, int dsize) 1411{ 1412 __uprobe_perf_func(tu, func, regs, ucb, dsize); 1413} 1414 1415int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type, 1416 const char **filename, u64 *probe_offset, 1417 u64 *probe_addr, bool perf_type_tracepoint) 1418{ 1419 const char *pevent = trace_event_name(event->tp_event); 1420 const char *group = event->tp_event->class->system; 1421 struct trace_uprobe *tu; 1422 1423 if (perf_type_tracepoint) 1424 tu = find_probe_event(pevent, group); 1425 else 1426 tu = trace_uprobe_primary_from_call(event->tp_event); 1427 if (!tu) 1428 return -EINVAL; 1429 1430 *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE 1431 : BPF_FD_TYPE_UPROBE; 1432 *filename = tu->filename; 1433 *probe_offset = tu->offset; 1434 *probe_addr = 0; 1435 return 0; 1436} 1437#endif /* CONFIG_PERF_EVENTS */ 1438 1439static int 1440trace_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 1473static 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, NULL); 1494 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1495 1496 ucb = uprobe_buffer_get(); 1497 store_trace_args(ucb->buf, &tu->tp, regs, NULL, 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 1510static 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, NULL); 1529 esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); 1530 1531 ucb = uprobe_buffer_get(); 1532 store_trace_args(ucb->buf, &tu->tp, regs, NULL, 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 1545static struct trace_event_functions uprobe_funcs = { 1546 .trace = print_uprobe_event 1547}; 1548 1549static struct trace_event_fields uprobe_fields_array[] = { 1550 { .type = TRACE_FUNCTION_TYPE, 1551 .define_fields = uprobe_event_define_fields }, 1552 {} 1553}; 1554 1555static 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 1565static 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 1572static 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 1578struct trace_event_call * 1579create_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); 1629error: 1630 free_trace_uprobe(tu); 1631 return ERR_PTR(ret); 1632} 1633 1634void 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 */ 1645static __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 1665fs_initcall(init_uprobe_trace); 1666