1 /* 2 * Common code for probe-based Dynamic events. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public License 14 * along with this program; if not, write to the Free Software 15 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 16 * 17 * This code was copied from kernel/trace/trace_kprobe.c written by 18 * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> 19 * 20 * Updates to make this generic: 21 * Copyright (C) IBM Corporation, 2010-2011 22 * Author: Srikar Dronamraju 23 */ 24 #define pr_fmt(fmt) "trace_probe: " fmt 25 26 #include "trace_probe.h" 27 28 const char *reserved_field_names[] = { 29 "common_type", 30 "common_flags", 31 "common_preempt_count", 32 "common_pid", 33 "common_tgid", 34 FIELD_STRING_IP, 35 FIELD_STRING_RETIP, 36 FIELD_STRING_FUNC, 37 }; 38 39 /* Printing in basic type function template */ 40 #define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \ 41 int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, const char *name, \ 42 void *data, void *ent) \ 43 { \ 44 trace_seq_printf(s, " %s=" fmt, name, *(type *)data); \ 45 return !trace_seq_has_overflowed(s); \ 46 } \ 47 const char PRINT_TYPE_FMT_NAME(tname)[] = fmt; \ 48 NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(tname)); 49 50 DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u") 51 DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u") 52 DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u") 53 DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu") 54 DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d") 55 DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d") 56 DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d") 57 DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld") 58 DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x") 59 DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x") 60 DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x") 61 DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx") 62 63 /* Print type function for string type */ 64 int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, const char *name, 65 void *data, void *ent) 66 { 67 int len = *(u32 *)data >> 16; 68 69 if (!len) 70 trace_seq_printf(s, " %s=(fault)", name); 71 else 72 trace_seq_printf(s, " %s=\"%s\"", name, 73 (const char *)get_loc_data(data, ent)); 74 return !trace_seq_has_overflowed(s); 75 } 76 NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(string)); 77 78 const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; 79 80 #define CHECK_FETCH_FUNCS(method, fn) \ 81 (((FETCH_FUNC_NAME(method, u8) == fn) || \ 82 (FETCH_FUNC_NAME(method, u16) == fn) || \ 83 (FETCH_FUNC_NAME(method, u32) == fn) || \ 84 (FETCH_FUNC_NAME(method, u64) == fn) || \ 85 (FETCH_FUNC_NAME(method, string) == fn) || \ 86 (FETCH_FUNC_NAME(method, string_size) == fn)) \ 87 && (fn != NULL)) 88 89 /* Data fetch function templates */ 90 #define DEFINE_FETCH_reg(type) \ 91 void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, void *offset, void *dest) \ 92 { \ 93 *(type *)dest = (type)regs_get_register(regs, \ 94 (unsigned int)((unsigned long)offset)); \ 95 } \ 96 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(reg, type)); 97 DEFINE_BASIC_FETCH_FUNCS(reg) 98 /* No string on the register */ 99 #define fetch_reg_string NULL 100 #define fetch_reg_string_size NULL 101 102 #define DEFINE_FETCH_retval(type) \ 103 void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \ 104 void *dummy, void *dest) \ 105 { \ 106 *(type *)dest = (type)regs_return_value(regs); \ 107 } \ 108 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(retval, type)); 109 DEFINE_BASIC_FETCH_FUNCS(retval) 110 /* No string on the retval */ 111 #define fetch_retval_string NULL 112 #define fetch_retval_string_size NULL 113 114 /* Dereference memory access function */ 115 struct deref_fetch_param { 116 struct fetch_param orig; 117 long offset; 118 fetch_func_t fetch; 119 fetch_func_t fetch_size; 120 }; 121 122 #define DEFINE_FETCH_deref(type) \ 123 void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \ 124 void *data, void *dest) \ 125 { \ 126 struct deref_fetch_param *dprm = data; \ 127 unsigned long addr; \ 128 call_fetch(&dprm->orig, regs, &addr); \ 129 if (addr) { \ 130 addr += dprm->offset; \ 131 dprm->fetch(regs, (void *)addr, dest); \ 132 } else \ 133 *(type *)dest = 0; \ 134 } \ 135 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, type)); 136 DEFINE_BASIC_FETCH_FUNCS(deref) 137 DEFINE_FETCH_deref(string) 138 139 void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs, 140 void *data, void *dest) 141 { 142 struct deref_fetch_param *dprm = data; 143 unsigned long addr; 144 145 call_fetch(&dprm->orig, regs, &addr); 146 if (addr && dprm->fetch_size) { 147 addr += dprm->offset; 148 dprm->fetch_size(regs, (void *)addr, dest); 149 } else 150 *(string_size *)dest = 0; 151 } 152 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, string_size)); 153 154 static void update_deref_fetch_param(struct deref_fetch_param *data) 155 { 156 if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) 157 update_deref_fetch_param(data->orig.data); 158 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) 159 update_symbol_cache(data->orig.data); 160 } 161 NOKPROBE_SYMBOL(update_deref_fetch_param); 162 163 static void free_deref_fetch_param(struct deref_fetch_param *data) 164 { 165 if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) 166 free_deref_fetch_param(data->orig.data); 167 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) 168 free_symbol_cache(data->orig.data); 169 kfree(data); 170 } 171 NOKPROBE_SYMBOL(free_deref_fetch_param); 172 173 /* Bitfield fetch function */ 174 struct bitfield_fetch_param { 175 struct fetch_param orig; 176 unsigned char hi_shift; 177 unsigned char low_shift; 178 }; 179 180 #define DEFINE_FETCH_bitfield(type) \ 181 void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \ 182 void *data, void *dest) \ 183 { \ 184 struct bitfield_fetch_param *bprm = data; \ 185 type buf = 0; \ 186 call_fetch(&bprm->orig, regs, &buf); \ 187 if (buf) { \ 188 buf <<= bprm->hi_shift; \ 189 buf >>= bprm->low_shift; \ 190 } \ 191 *(type *)dest = buf; \ 192 } \ 193 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(bitfield, type)); 194 DEFINE_BASIC_FETCH_FUNCS(bitfield) 195 #define fetch_bitfield_string NULL 196 #define fetch_bitfield_string_size NULL 197 198 static void 199 update_bitfield_fetch_param(struct bitfield_fetch_param *data) 200 { 201 /* 202 * Don't check the bitfield itself, because this must be the 203 * last fetch function. 204 */ 205 if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) 206 update_deref_fetch_param(data->orig.data); 207 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) 208 update_symbol_cache(data->orig.data); 209 } 210 211 static void 212 free_bitfield_fetch_param(struct bitfield_fetch_param *data) 213 { 214 /* 215 * Don't check the bitfield itself, because this must be the 216 * last fetch function. 217 */ 218 if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) 219 free_deref_fetch_param(data->orig.data); 220 else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) 221 free_symbol_cache(data->orig.data); 222 223 kfree(data); 224 } 225 226 void FETCH_FUNC_NAME(comm, string)(struct pt_regs *regs, 227 void *data, void *dest) 228 { 229 int maxlen = get_rloc_len(*(u32 *)dest); 230 u8 *dst = get_rloc_data(dest); 231 long ret; 232 233 if (!maxlen) 234 return; 235 236 ret = strlcpy(dst, current->comm, maxlen); 237 *(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest)); 238 } 239 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string)); 240 241 void FETCH_FUNC_NAME(comm, string_size)(struct pt_regs *regs, 242 void *data, void *dest) 243 { 244 *(u32 *)dest = strlen(current->comm) + 1; 245 } 246 NOKPROBE_SYMBOL(FETCH_FUNC_NAME(comm, string_size)); 247 248 static const struct fetch_type *find_fetch_type(const char *type, 249 const struct fetch_type *ftbl) 250 { 251 int i; 252 253 if (!type) 254 type = DEFAULT_FETCH_TYPE_STR; 255 256 /* Special case: bitfield */ 257 if (*type == 'b') { 258 unsigned long bs; 259 260 type = strchr(type, '/'); 261 if (!type) 262 goto fail; 263 264 type++; 265 if (kstrtoul(type, 0, &bs)) 266 goto fail; 267 268 switch (bs) { 269 case 8: 270 return find_fetch_type("u8", ftbl); 271 case 16: 272 return find_fetch_type("u16", ftbl); 273 case 32: 274 return find_fetch_type("u32", ftbl); 275 case 64: 276 return find_fetch_type("u64", ftbl); 277 default: 278 goto fail; 279 } 280 } 281 282 for (i = 0; ftbl[i].name; i++) { 283 if (strcmp(type, ftbl[i].name) == 0) 284 return &ftbl[i]; 285 } 286 287 fail: 288 return NULL; 289 } 290 291 /* Special function : only accept unsigned long */ 292 static void fetch_kernel_stack_address(struct pt_regs *regs, void *dummy, void *dest) 293 { 294 *(unsigned long *)dest = kernel_stack_pointer(regs); 295 } 296 NOKPROBE_SYMBOL(fetch_kernel_stack_address); 297 298 static void fetch_user_stack_address(struct pt_regs *regs, void *dummy, void *dest) 299 { 300 *(unsigned long *)dest = user_stack_pointer(regs); 301 } 302 NOKPROBE_SYMBOL(fetch_user_stack_address); 303 304 static fetch_func_t get_fetch_size_function(const struct fetch_type *type, 305 fetch_func_t orig_fn, 306 const struct fetch_type *ftbl) 307 { 308 int i; 309 310 if (type != &ftbl[FETCH_TYPE_STRING]) 311 return NULL; /* Only string type needs size function */ 312 313 for (i = 0; i < FETCH_MTD_END; i++) 314 if (type->fetch[i] == orig_fn) 315 return ftbl[FETCH_TYPE_STRSIZE].fetch[i]; 316 317 WARN_ON(1); /* This should not happen */ 318 319 return NULL; 320 } 321 322 /* Split symbol and offset. */ 323 int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset) 324 { 325 char *tmp; 326 int ret; 327 328 if (!offset) 329 return -EINVAL; 330 331 tmp = strchr(symbol, '+'); 332 if (tmp) { 333 /* skip sign because kstrtoul doesn't accept '+' */ 334 ret = kstrtoul(tmp + 1, 0, offset); 335 if (ret) 336 return ret; 337 338 *tmp = '\0'; 339 } else 340 *offset = 0; 341 342 return 0; 343 } 344 345 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) 346 347 static int parse_probe_vars(char *arg, const struct fetch_type *t, 348 struct fetch_param *f, bool is_return, 349 bool is_kprobe) 350 { 351 int ret = 0; 352 unsigned long param; 353 354 if (strcmp(arg, "retval") == 0) { 355 if (is_return) 356 f->fn = t->fetch[FETCH_MTD_retval]; 357 else 358 ret = -EINVAL; 359 } else if (strncmp(arg, "stack", 5) == 0) { 360 if (arg[5] == '\0') { 361 if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR)) 362 return -EINVAL; 363 364 if (is_kprobe) 365 f->fn = fetch_kernel_stack_address; 366 else 367 f->fn = fetch_user_stack_address; 368 } else if (isdigit(arg[5])) { 369 ret = kstrtoul(arg + 5, 10, ¶m); 370 if (ret || (is_kprobe && param > PARAM_MAX_STACK)) 371 ret = -EINVAL; 372 else { 373 f->fn = t->fetch[FETCH_MTD_stack]; 374 f->data = (void *)param; 375 } 376 } else 377 ret = -EINVAL; 378 } else if (strcmp(arg, "comm") == 0) { 379 if (strcmp(t->name, "string") != 0 && 380 strcmp(t->name, "string_size") != 0) 381 return -EINVAL; 382 f->fn = t->fetch[FETCH_MTD_comm]; 383 } else 384 ret = -EINVAL; 385 386 return ret; 387 } 388 389 /* Recursive argument parser */ 390 static int parse_probe_arg(char *arg, const struct fetch_type *t, 391 struct fetch_param *f, bool is_return, bool is_kprobe, 392 const struct fetch_type *ftbl) 393 { 394 unsigned long param; 395 long offset; 396 char *tmp; 397 int ret = 0; 398 399 switch (arg[0]) { 400 case '$': 401 ret = parse_probe_vars(arg + 1, t, f, is_return, is_kprobe); 402 break; 403 404 case '%': /* named register */ 405 ret = regs_query_register_offset(arg + 1); 406 if (ret >= 0) { 407 f->fn = t->fetch[FETCH_MTD_reg]; 408 f->data = (void *)(unsigned long)ret; 409 ret = 0; 410 } 411 break; 412 413 case '@': /* memory, file-offset or symbol */ 414 if (isdigit(arg[1])) { 415 ret = kstrtoul(arg + 1, 0, ¶m); 416 if (ret) 417 break; 418 419 f->fn = t->fetch[FETCH_MTD_memory]; 420 f->data = (void *)param; 421 } else if (arg[1] == '+') { 422 /* kprobes don't support file offsets */ 423 if (is_kprobe) 424 return -EINVAL; 425 426 ret = kstrtol(arg + 2, 0, &offset); 427 if (ret) 428 break; 429 430 f->fn = t->fetch[FETCH_MTD_file_offset]; 431 f->data = (void *)offset; 432 } else { 433 /* uprobes don't support symbols */ 434 if (!is_kprobe) 435 return -EINVAL; 436 437 ret = traceprobe_split_symbol_offset(arg + 1, &offset); 438 if (ret) 439 break; 440 441 f->data = alloc_symbol_cache(arg + 1, offset); 442 if (f->data) 443 f->fn = t->fetch[FETCH_MTD_symbol]; 444 } 445 break; 446 447 case '+': /* deref memory */ 448 arg++; /* Skip '+', because kstrtol() rejects it. */ 449 case '-': 450 tmp = strchr(arg, '('); 451 if (!tmp) 452 break; 453 454 *tmp = '\0'; 455 ret = kstrtol(arg, 0, &offset); 456 457 if (ret) 458 break; 459 460 arg = tmp + 1; 461 tmp = strrchr(arg, ')'); 462 463 if (tmp) { 464 struct deref_fetch_param *dprm; 465 const struct fetch_type *t2; 466 467 t2 = find_fetch_type(NULL, ftbl); 468 *tmp = '\0'; 469 dprm = kzalloc(sizeof(struct deref_fetch_param), GFP_KERNEL); 470 471 if (!dprm) 472 return -ENOMEM; 473 474 dprm->offset = offset; 475 dprm->fetch = t->fetch[FETCH_MTD_memory]; 476 dprm->fetch_size = get_fetch_size_function(t, 477 dprm->fetch, ftbl); 478 ret = parse_probe_arg(arg, t2, &dprm->orig, is_return, 479 is_kprobe, ftbl); 480 if (ret) 481 kfree(dprm); 482 else { 483 f->fn = t->fetch[FETCH_MTD_deref]; 484 f->data = (void *)dprm; 485 } 486 } 487 break; 488 } 489 if (!ret && !f->fn) { /* Parsed, but do not find fetch method */ 490 pr_info("%s type has no corresponding fetch method.\n", t->name); 491 ret = -EINVAL; 492 } 493 494 return ret; 495 } 496 497 #define BYTES_TO_BITS(nb) ((BITS_PER_LONG * (nb)) / sizeof(long)) 498 499 /* Bitfield type needs to be parsed into a fetch function */ 500 static int __parse_bitfield_probe_arg(const char *bf, 501 const struct fetch_type *t, 502 struct fetch_param *f) 503 { 504 struct bitfield_fetch_param *bprm; 505 unsigned long bw, bo; 506 char *tail; 507 508 if (*bf != 'b') 509 return 0; 510 511 bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); 512 if (!bprm) 513 return -ENOMEM; 514 515 bprm->orig = *f; 516 f->fn = t->fetch[FETCH_MTD_bitfield]; 517 f->data = (void *)bprm; 518 bw = simple_strtoul(bf + 1, &tail, 0); /* Use simple one */ 519 520 if (bw == 0 || *tail != '@') 521 return -EINVAL; 522 523 bf = tail + 1; 524 bo = simple_strtoul(bf, &tail, 0); 525 526 if (tail == bf || *tail != '/') 527 return -EINVAL; 528 529 bprm->hi_shift = BYTES_TO_BITS(t->size) - (bw + bo); 530 bprm->low_shift = bprm->hi_shift + bo; 531 532 return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; 533 } 534 535 /* String length checking wrapper */ 536 int traceprobe_parse_probe_arg(char *arg, ssize_t *size, 537 struct probe_arg *parg, bool is_return, bool is_kprobe, 538 const struct fetch_type *ftbl) 539 { 540 const char *t; 541 int ret; 542 543 if (strlen(arg) > MAX_ARGSTR_LEN) { 544 pr_info("Argument is too long.: %s\n", arg); 545 return -ENOSPC; 546 } 547 parg->comm = kstrdup(arg, GFP_KERNEL); 548 if (!parg->comm) { 549 pr_info("Failed to allocate memory for command '%s'.\n", arg); 550 return -ENOMEM; 551 } 552 t = strchr(parg->comm, ':'); 553 if (t) { 554 arg[t - parg->comm] = '\0'; 555 t++; 556 } 557 /* 558 * The default type of $comm should be "string", and it can't be 559 * dereferenced. 560 */ 561 if (!t && strcmp(arg, "$comm") == 0) 562 t = "string"; 563 parg->type = find_fetch_type(t, ftbl); 564 if (!parg->type) { 565 pr_info("Unsupported type: %s\n", t); 566 return -EINVAL; 567 } 568 parg->offset = *size; 569 *size += parg->type->size; 570 ret = parse_probe_arg(arg, parg->type, &parg->fetch, is_return, 571 is_kprobe, ftbl); 572 573 if (ret >= 0 && t != NULL) 574 ret = __parse_bitfield_probe_arg(t, parg->type, &parg->fetch); 575 576 if (ret >= 0) { 577 parg->fetch_size.fn = get_fetch_size_function(parg->type, 578 parg->fetch.fn, 579 ftbl); 580 parg->fetch_size.data = parg->fetch.data; 581 } 582 583 return ret; 584 } 585 586 /* Return 1 if name is reserved or already used by another argument */ 587 int traceprobe_conflict_field_name(const char *name, 588 struct probe_arg *args, int narg) 589 { 590 int i; 591 592 for (i = 0; i < ARRAY_SIZE(reserved_field_names); i++) 593 if (strcmp(reserved_field_names[i], name) == 0) 594 return 1; 595 596 for (i = 0; i < narg; i++) 597 if (strcmp(args[i].name, name) == 0) 598 return 1; 599 600 return 0; 601 } 602 603 void traceprobe_update_arg(struct probe_arg *arg) 604 { 605 if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) 606 update_bitfield_fetch_param(arg->fetch.data); 607 else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) 608 update_deref_fetch_param(arg->fetch.data); 609 else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) 610 update_symbol_cache(arg->fetch.data); 611 } 612 613 void traceprobe_free_probe_arg(struct probe_arg *arg) 614 { 615 if (CHECK_FETCH_FUNCS(bitfield, arg->fetch.fn)) 616 free_bitfield_fetch_param(arg->fetch.data); 617 else if (CHECK_FETCH_FUNCS(deref, arg->fetch.fn)) 618 free_deref_fetch_param(arg->fetch.data); 619 else if (CHECK_FETCH_FUNCS(symbol, arg->fetch.fn)) 620 free_symbol_cache(arg->fetch.data); 621 622 kfree(arg->name); 623 kfree(arg->comm); 624 } 625 626 int traceprobe_command(const char *buf, int (*createfn)(int, char **)) 627 { 628 char **argv; 629 int argc, ret; 630 631 argc = 0; 632 ret = 0; 633 argv = argv_split(GFP_KERNEL, buf, &argc); 634 if (!argv) 635 return -ENOMEM; 636 637 if (argc) 638 ret = createfn(argc, argv); 639 640 argv_free(argv); 641 642 return ret; 643 } 644 645 #define WRITE_BUFSIZE 4096 646 647 ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer, 648 size_t count, loff_t *ppos, 649 int (*createfn)(int, char **)) 650 { 651 char *kbuf, *buf, *tmp; 652 int ret = 0; 653 size_t done = 0; 654 size_t size; 655 656 kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL); 657 if (!kbuf) 658 return -ENOMEM; 659 660 while (done < count) { 661 size = count - done; 662 663 if (size >= WRITE_BUFSIZE) 664 size = WRITE_BUFSIZE - 1; 665 666 if (copy_from_user(kbuf, buffer + done, size)) { 667 ret = -EFAULT; 668 goto out; 669 } 670 kbuf[size] = '\0'; 671 buf = kbuf; 672 do { 673 tmp = strchr(buf, '\n'); 674 if (tmp) { 675 *tmp = '\0'; 676 size = tmp - buf + 1; 677 } else { 678 size = strlen(buf); 679 if (done + size < count) { 680 if (buf != kbuf) 681 break; 682 /* This can accept WRITE_BUFSIZE - 2 ('\n' + '\0') */ 683 pr_warn("Line length is too long: Should be less than %d\n", 684 WRITE_BUFSIZE - 2); 685 ret = -EINVAL; 686 goto out; 687 } 688 } 689 done += size; 690 691 /* Remove comments */ 692 tmp = strchr(buf, '#'); 693 694 if (tmp) 695 *tmp = '\0'; 696 697 ret = traceprobe_command(buf, createfn); 698 if (ret) 699 goto out; 700 buf += size; 701 702 } while (done < count); 703 } 704 ret = done; 705 706 out: 707 kfree(kbuf); 708 709 return ret; 710 } 711 712 static int __set_print_fmt(struct trace_probe *tp, char *buf, int len, 713 bool is_return) 714 { 715 int i; 716 int pos = 0; 717 718 const char *fmt, *arg; 719 720 if (!is_return) { 721 fmt = "(%lx)"; 722 arg = "REC->" FIELD_STRING_IP; 723 } else { 724 fmt = "(%lx <- %lx)"; 725 arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP; 726 } 727 728 /* When len=0, we just calculate the needed length */ 729 #define LEN_OR_ZERO (len ? len - pos : 0) 730 731 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt); 732 733 for (i = 0; i < tp->nr_args; i++) { 734 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s", 735 tp->args[i].name, tp->args[i].type->fmt); 736 } 737 738 pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg); 739 740 for (i = 0; i < tp->nr_args; i++) { 741 if (strcmp(tp->args[i].type->name, "string") == 0) 742 pos += snprintf(buf + pos, LEN_OR_ZERO, 743 ", __get_str(%s)", 744 tp->args[i].name); 745 else 746 pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s", 747 tp->args[i].name); 748 } 749 750 #undef LEN_OR_ZERO 751 752 /* return the length of print_fmt */ 753 return pos; 754 } 755 756 int set_print_fmt(struct trace_probe *tp, bool is_return) 757 { 758 int len; 759 char *print_fmt; 760 761 /* First: called with 0 length to calculate the needed length */ 762 len = __set_print_fmt(tp, NULL, 0, is_return); 763 print_fmt = kmalloc(len + 1, GFP_KERNEL); 764 if (!print_fmt) 765 return -ENOMEM; 766 767 /* Second: actually write the @print_fmt */ 768 __set_print_fmt(tp, print_fmt, len + 1, is_return); 769 tp->call.print_fmt = print_fmt; 770 771 return 0; 772 } 773