1 /* 2 * lib/dynamic_debug.c 3 * 4 * make pr_debug()/dev_dbg() calls runtime configurable based upon their 5 * source module. 6 * 7 * Copyright (C) 2008 Jason Baron <jbaron@redhat.com> 8 * By Greg Banks <gnb@melbourne.sgi.com> 9 * Copyright (c) 2008 Silicon Graphics Inc. All Rights Reserved. 10 * Copyright (C) 2011 Bart Van Assche. All Rights Reserved. 11 */ 12 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <linux/moduleparam.h> 16 #include <linux/kallsyms.h> 17 #include <linux/version.h> 18 #include <linux/types.h> 19 #include <linux/mutex.h> 20 #include <linux/proc_fs.h> 21 #include <linux/seq_file.h> 22 #include <linux/list.h> 23 #include <linux/sysctl.h> 24 #include <linux/ctype.h> 25 #include <linux/string.h> 26 #include <linux/uaccess.h> 27 #include <linux/dynamic_debug.h> 28 #include <linux/debugfs.h> 29 #include <linux/slab.h> 30 #include <linux/jump_label.h> 31 #include <linux/hardirq.h> 32 #include <linux/sched.h> 33 34 extern struct _ddebug __start___verbose[]; 35 extern struct _ddebug __stop___verbose[]; 36 37 struct ddebug_table { 38 struct list_head link; 39 char *mod_name; 40 unsigned int num_ddebugs; 41 unsigned int num_enabled; 42 struct _ddebug *ddebugs; 43 }; 44 45 struct ddebug_query { 46 const char *filename; 47 const char *module; 48 const char *function; 49 const char *format; 50 unsigned int first_lineno, last_lineno; 51 }; 52 53 struct ddebug_iter { 54 struct ddebug_table *table; 55 unsigned int idx; 56 }; 57 58 static DEFINE_MUTEX(ddebug_lock); 59 static LIST_HEAD(ddebug_tables); 60 static int verbose = 0; 61 62 /* Return the last part of a pathname */ 63 static inline const char *basename(const char *path) 64 { 65 const char *tail = strrchr(path, '/'); 66 return tail ? tail+1 : path; 67 } 68 69 static struct { unsigned flag:8; char opt_char; } opt_array[] = { 70 { _DPRINTK_FLAGS_PRINT, 'p' }, 71 { _DPRINTK_FLAGS_INCL_MODNAME, 'm' }, 72 { _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' }, 73 { _DPRINTK_FLAGS_INCL_LINENO, 'l' }, 74 { _DPRINTK_FLAGS_INCL_TID, 't' }, 75 }; 76 77 /* format a string into buf[] which describes the _ddebug's flags */ 78 static char *ddebug_describe_flags(struct _ddebug *dp, char *buf, 79 size_t maxlen) 80 { 81 char *p = buf; 82 int i; 83 84 BUG_ON(maxlen < 4); 85 for (i = 0; i < ARRAY_SIZE(opt_array); ++i) 86 if (dp->flags & opt_array[i].flag) 87 *p++ = opt_array[i].opt_char; 88 if (p == buf) 89 *p++ = '-'; 90 *p = '\0'; 91 92 return buf; 93 } 94 95 /* 96 * Search the tables for _ddebug's which match the given 97 * `query' and apply the `flags' and `mask' to them. Tells 98 * the user which ddebug's were changed, or whether none 99 * were matched. 100 */ 101 static void ddebug_change(const struct ddebug_query *query, 102 unsigned int flags, unsigned int mask) 103 { 104 int i; 105 struct ddebug_table *dt; 106 unsigned int newflags; 107 unsigned int nfound = 0; 108 char flagbuf[8]; 109 110 /* search for matching ddebugs */ 111 mutex_lock(&ddebug_lock); 112 list_for_each_entry(dt, &ddebug_tables, link) { 113 114 /* match against the module name */ 115 if (query->module != NULL && 116 strcmp(query->module, dt->mod_name)) 117 continue; 118 119 for (i = 0 ; i < dt->num_ddebugs ; i++) { 120 struct _ddebug *dp = &dt->ddebugs[i]; 121 122 /* match against the source filename */ 123 if (query->filename != NULL && 124 strcmp(query->filename, dp->filename) && 125 strcmp(query->filename, basename(dp->filename))) 126 continue; 127 128 /* match against the function */ 129 if (query->function != NULL && 130 strcmp(query->function, dp->function)) 131 continue; 132 133 /* match against the format */ 134 if (query->format != NULL && 135 strstr(dp->format, query->format) == NULL) 136 continue; 137 138 /* match against the line number range */ 139 if (query->first_lineno && 140 dp->lineno < query->first_lineno) 141 continue; 142 if (query->last_lineno && 143 dp->lineno > query->last_lineno) 144 continue; 145 146 nfound++; 147 148 newflags = (dp->flags & mask) | flags; 149 if (newflags == dp->flags) 150 continue; 151 152 if (!newflags) 153 dt->num_enabled--; 154 else if (!dp->flags) 155 dt->num_enabled++; 156 dp->flags = newflags; 157 if (newflags) 158 dp->enabled = 1; 159 else 160 dp->enabled = 0; 161 if (verbose) 162 printk(KERN_INFO 163 "ddebug: changed %s:%d [%s]%s %s\n", 164 dp->filename, dp->lineno, 165 dt->mod_name, dp->function, 166 ddebug_describe_flags(dp, flagbuf, 167 sizeof(flagbuf))); 168 } 169 } 170 mutex_unlock(&ddebug_lock); 171 172 if (!nfound && verbose) 173 printk(KERN_INFO "ddebug: no matches for query\n"); 174 } 175 176 /* 177 * Split the buffer `buf' into space-separated words. 178 * Handles simple " and ' quoting, i.e. without nested, 179 * embedded or escaped \". Return the number of words 180 * or <0 on error. 181 */ 182 static int ddebug_tokenize(char *buf, char *words[], int maxwords) 183 { 184 int nwords = 0; 185 186 while (*buf) { 187 char *end; 188 189 /* Skip leading whitespace */ 190 buf = skip_spaces(buf); 191 if (!*buf) 192 break; /* oh, it was trailing whitespace */ 193 194 /* Run `end' over a word, either whitespace separated or quoted */ 195 if (*buf == '"' || *buf == '\'') { 196 int quote = *buf++; 197 for (end = buf ; *end && *end != quote ; end++) 198 ; 199 if (!*end) 200 return -EINVAL; /* unclosed quote */ 201 } else { 202 for (end = buf ; *end && !isspace(*end) ; end++) 203 ; 204 BUG_ON(end == buf); 205 } 206 /* Here `buf' is the start of the word, `end' is one past the end */ 207 208 if (nwords == maxwords) 209 return -EINVAL; /* ran out of words[] before bytes */ 210 if (*end) 211 *end++ = '\0'; /* terminate the word */ 212 words[nwords++] = buf; 213 buf = end; 214 } 215 216 if (verbose) { 217 int i; 218 printk(KERN_INFO "%s: split into words:", __func__); 219 for (i = 0 ; i < nwords ; i++) 220 printk(" \"%s\"", words[i]); 221 printk("\n"); 222 } 223 224 return nwords; 225 } 226 227 /* 228 * Parse a single line number. Note that the empty string "" 229 * is treated as a special case and converted to zero, which 230 * is later treated as a "don't care" value. 231 */ 232 static inline int parse_lineno(const char *str, unsigned int *val) 233 { 234 char *end = NULL; 235 BUG_ON(str == NULL); 236 if (*str == '\0') { 237 *val = 0; 238 return 0; 239 } 240 *val = simple_strtoul(str, &end, 10); 241 return end == NULL || end == str || *end != '\0' ? -EINVAL : 0; 242 } 243 244 /* 245 * Undo octal escaping in a string, inplace. This is useful to 246 * allow the user to express a query which matches a format 247 * containing embedded spaces. 248 */ 249 #define isodigit(c) ((c) >= '0' && (c) <= '7') 250 static char *unescape(char *str) 251 { 252 char *in = str; 253 char *out = str; 254 255 while (*in) { 256 if (*in == '\\') { 257 if (in[1] == '\\') { 258 *out++ = '\\'; 259 in += 2; 260 continue; 261 } else if (in[1] == 't') { 262 *out++ = '\t'; 263 in += 2; 264 continue; 265 } else if (in[1] == 'n') { 266 *out++ = '\n'; 267 in += 2; 268 continue; 269 } else if (isodigit(in[1]) && 270 isodigit(in[2]) && 271 isodigit(in[3])) { 272 *out++ = ((in[1] - '0')<<6) | 273 ((in[2] - '0')<<3) | 274 (in[3] - '0'); 275 in += 4; 276 continue; 277 } 278 } 279 *out++ = *in++; 280 } 281 *out = '\0'; 282 283 return str; 284 } 285 286 /* 287 * Parse words[] as a ddebug query specification, which is a series 288 * of (keyword, value) pairs chosen from these possibilities: 289 * 290 * func <function-name> 291 * file <full-pathname> 292 * file <base-filename> 293 * module <module-name> 294 * format <escaped-string-to-find-in-format> 295 * line <lineno> 296 * line <first-lineno>-<last-lineno> // where either may be empty 297 */ 298 static int ddebug_parse_query(char *words[], int nwords, 299 struct ddebug_query *query) 300 { 301 unsigned int i; 302 303 /* check we have an even number of words */ 304 if (nwords % 2 != 0) 305 return -EINVAL; 306 memset(query, 0, sizeof(*query)); 307 308 for (i = 0 ; i < nwords ; i += 2) { 309 if (!strcmp(words[i], "func")) 310 query->function = words[i+1]; 311 else if (!strcmp(words[i], "file")) 312 query->filename = words[i+1]; 313 else if (!strcmp(words[i], "module")) 314 query->module = words[i+1]; 315 else if (!strcmp(words[i], "format")) 316 query->format = unescape(words[i+1]); 317 else if (!strcmp(words[i], "line")) { 318 char *first = words[i+1]; 319 char *last = strchr(first, '-'); 320 if (last) 321 *last++ = '\0'; 322 if (parse_lineno(first, &query->first_lineno) < 0) 323 return -EINVAL; 324 if (last != NULL) { 325 /* range <first>-<last> */ 326 if (parse_lineno(last, &query->last_lineno) < 0) 327 return -EINVAL; 328 } else { 329 query->last_lineno = query->first_lineno; 330 } 331 } else { 332 if (verbose) 333 printk(KERN_ERR "%s: unknown keyword \"%s\"\n", 334 __func__, words[i]); 335 return -EINVAL; 336 } 337 } 338 339 if (verbose) 340 printk(KERN_INFO "%s: q->function=\"%s\" q->filename=\"%s\" " 341 "q->module=\"%s\" q->format=\"%s\" q->lineno=%u-%u\n", 342 __func__, query->function, query->filename, 343 query->module, query->format, query->first_lineno, 344 query->last_lineno); 345 346 return 0; 347 } 348 349 /* 350 * Parse `str' as a flags specification, format [-+=][p]+. 351 * Sets up *maskp and *flagsp to be used when changing the 352 * flags fields of matched _ddebug's. Returns 0 on success 353 * or <0 on error. 354 */ 355 static int ddebug_parse_flags(const char *str, unsigned int *flagsp, 356 unsigned int *maskp) 357 { 358 unsigned flags = 0; 359 int op = '=', i; 360 361 switch (*str) { 362 case '+': 363 case '-': 364 case '=': 365 op = *str++; 366 break; 367 default: 368 return -EINVAL; 369 } 370 if (verbose) 371 printk(KERN_INFO "%s: op='%c'\n", __func__, op); 372 373 for ( ; *str ; ++str) { 374 for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) { 375 if (*str == opt_array[i].opt_char) { 376 flags |= opt_array[i].flag; 377 break; 378 } 379 } 380 if (i < 0) 381 return -EINVAL; 382 } 383 if (flags == 0) 384 return -EINVAL; 385 if (verbose) 386 printk(KERN_INFO "%s: flags=0x%x\n", __func__, flags); 387 388 /* calculate final *flagsp, *maskp according to mask and op */ 389 switch (op) { 390 case '=': 391 *maskp = 0; 392 *flagsp = flags; 393 break; 394 case '+': 395 *maskp = ~0U; 396 *flagsp = flags; 397 break; 398 case '-': 399 *maskp = ~flags; 400 *flagsp = 0; 401 break; 402 } 403 if (verbose) 404 printk(KERN_INFO "%s: *flagsp=0x%x *maskp=0x%x\n", 405 __func__, *flagsp, *maskp); 406 return 0; 407 } 408 409 static int ddebug_exec_query(char *query_string) 410 { 411 unsigned int flags = 0, mask = 0; 412 struct ddebug_query query; 413 #define MAXWORDS 9 414 int nwords; 415 char *words[MAXWORDS]; 416 417 nwords = ddebug_tokenize(query_string, words, MAXWORDS); 418 if (nwords <= 0) 419 return -EINVAL; 420 if (ddebug_parse_query(words, nwords-1, &query)) 421 return -EINVAL; 422 if (ddebug_parse_flags(words[nwords-1], &flags, &mask)) 423 return -EINVAL; 424 425 /* actually go and implement the change */ 426 ddebug_change(&query, flags, mask); 427 return 0; 428 } 429 430 int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...) 431 { 432 va_list args; 433 int res; 434 435 BUG_ON(!descriptor); 436 BUG_ON(!fmt); 437 438 va_start(args, fmt); 439 res = printk(KERN_DEBUG); 440 if (descriptor->flags & _DPRINTK_FLAGS_INCL_TID) { 441 if (in_interrupt()) 442 res += printk(KERN_CONT "<intr> "); 443 else 444 res += printk(KERN_CONT "[%d] ", task_pid_vnr(current)); 445 } 446 if (descriptor->flags & _DPRINTK_FLAGS_INCL_MODNAME) 447 res += printk(KERN_CONT "%s:", descriptor->modname); 448 if (descriptor->flags & _DPRINTK_FLAGS_INCL_FUNCNAME) 449 res += printk(KERN_CONT "%s:", descriptor->function); 450 if (descriptor->flags & _DPRINTK_FLAGS_INCL_LINENO) 451 res += printk(KERN_CONT "%d ", descriptor->lineno); 452 res += vprintk(fmt, args); 453 va_end(args); 454 455 return res; 456 } 457 EXPORT_SYMBOL(__dynamic_pr_debug); 458 459 static __initdata char ddebug_setup_string[1024]; 460 static __init int ddebug_setup_query(char *str) 461 { 462 if (strlen(str) >= 1024) { 463 pr_warning("ddebug boot param string too large\n"); 464 return 0; 465 } 466 strcpy(ddebug_setup_string, str); 467 return 1; 468 } 469 470 __setup("ddebug_query=", ddebug_setup_query); 471 472 /* 473 * File_ops->write method for <debugfs>/dynamic_debug/conrol. Gathers the 474 * command text from userspace, parses and executes it. 475 */ 476 static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf, 477 size_t len, loff_t *offp) 478 { 479 char tmpbuf[256]; 480 int ret; 481 482 if (len == 0) 483 return 0; 484 /* we don't check *offp -- multiple writes() are allowed */ 485 if (len > sizeof(tmpbuf)-1) 486 return -E2BIG; 487 if (copy_from_user(tmpbuf, ubuf, len)) 488 return -EFAULT; 489 tmpbuf[len] = '\0'; 490 if (verbose) 491 printk(KERN_INFO "%s: read %d bytes from userspace\n", 492 __func__, (int)len); 493 494 ret = ddebug_exec_query(tmpbuf); 495 if (ret) 496 return ret; 497 498 *offp += len; 499 return len; 500 } 501 502 /* 503 * Set the iterator to point to the first _ddebug object 504 * and return a pointer to that first object. Returns 505 * NULL if there are no _ddebugs at all. 506 */ 507 static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter) 508 { 509 if (list_empty(&ddebug_tables)) { 510 iter->table = NULL; 511 iter->idx = 0; 512 return NULL; 513 } 514 iter->table = list_entry(ddebug_tables.next, 515 struct ddebug_table, link); 516 iter->idx = 0; 517 return &iter->table->ddebugs[iter->idx]; 518 } 519 520 /* 521 * Advance the iterator to point to the next _ddebug 522 * object from the one the iterator currently points at, 523 * and returns a pointer to the new _ddebug. Returns 524 * NULL if the iterator has seen all the _ddebugs. 525 */ 526 static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter) 527 { 528 if (iter->table == NULL) 529 return NULL; 530 if (++iter->idx == iter->table->num_ddebugs) { 531 /* iterate to next table */ 532 iter->idx = 0; 533 if (list_is_last(&iter->table->link, &ddebug_tables)) { 534 iter->table = NULL; 535 return NULL; 536 } 537 iter->table = list_entry(iter->table->link.next, 538 struct ddebug_table, link); 539 } 540 return &iter->table->ddebugs[iter->idx]; 541 } 542 543 /* 544 * Seq_ops start method. Called at the start of every 545 * read() call from userspace. Takes the ddebug_lock and 546 * seeks the seq_file's iterator to the given position. 547 */ 548 static void *ddebug_proc_start(struct seq_file *m, loff_t *pos) 549 { 550 struct ddebug_iter *iter = m->private; 551 struct _ddebug *dp; 552 int n = *pos; 553 554 if (verbose) 555 printk(KERN_INFO "%s: called m=%p *pos=%lld\n", 556 __func__, m, (unsigned long long)*pos); 557 558 mutex_lock(&ddebug_lock); 559 560 if (!n) 561 return SEQ_START_TOKEN; 562 if (n < 0) 563 return NULL; 564 dp = ddebug_iter_first(iter); 565 while (dp != NULL && --n > 0) 566 dp = ddebug_iter_next(iter); 567 return dp; 568 } 569 570 /* 571 * Seq_ops next method. Called several times within a read() 572 * call from userspace, with ddebug_lock held. Walks to the 573 * next _ddebug object with a special case for the header line. 574 */ 575 static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos) 576 { 577 struct ddebug_iter *iter = m->private; 578 struct _ddebug *dp; 579 580 if (verbose) 581 printk(KERN_INFO "%s: called m=%p p=%p *pos=%lld\n", 582 __func__, m, p, (unsigned long long)*pos); 583 584 if (p == SEQ_START_TOKEN) 585 dp = ddebug_iter_first(iter); 586 else 587 dp = ddebug_iter_next(iter); 588 ++*pos; 589 return dp; 590 } 591 592 /* 593 * Seq_ops show method. Called several times within a read() 594 * call from userspace, with ddebug_lock held. Formats the 595 * current _ddebug as a single human-readable line, with a 596 * special case for the header line. 597 */ 598 static int ddebug_proc_show(struct seq_file *m, void *p) 599 { 600 struct ddebug_iter *iter = m->private; 601 struct _ddebug *dp = p; 602 char flagsbuf[8]; 603 604 if (verbose) 605 printk(KERN_INFO "%s: called m=%p p=%p\n", 606 __func__, m, p); 607 608 if (p == SEQ_START_TOKEN) { 609 seq_puts(m, 610 "# filename:lineno [module]function flags format\n"); 611 return 0; 612 } 613 614 seq_printf(m, "%s:%u [%s]%s %s \"", 615 dp->filename, dp->lineno, 616 iter->table->mod_name, dp->function, 617 ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf))); 618 seq_escape(m, dp->format, "\t\r\n\""); 619 seq_puts(m, "\"\n"); 620 621 return 0; 622 } 623 624 /* 625 * Seq_ops stop method. Called at the end of each read() 626 * call from userspace. Drops ddebug_lock. 627 */ 628 static void ddebug_proc_stop(struct seq_file *m, void *p) 629 { 630 if (verbose) 631 printk(KERN_INFO "%s: called m=%p p=%p\n", 632 __func__, m, p); 633 mutex_unlock(&ddebug_lock); 634 } 635 636 static const struct seq_operations ddebug_proc_seqops = { 637 .start = ddebug_proc_start, 638 .next = ddebug_proc_next, 639 .show = ddebug_proc_show, 640 .stop = ddebug_proc_stop 641 }; 642 643 /* 644 * File_ops->open method for <debugfs>/dynamic_debug/control. Does the seq_file 645 * setup dance, and also creates an iterator to walk the _ddebugs. 646 * Note that we create a seq_file always, even for O_WRONLY files 647 * where it's not needed, as doing so simplifies the ->release method. 648 */ 649 static int ddebug_proc_open(struct inode *inode, struct file *file) 650 { 651 struct ddebug_iter *iter; 652 int err; 653 654 if (verbose) 655 printk(KERN_INFO "%s: called\n", __func__); 656 657 iter = kzalloc(sizeof(*iter), GFP_KERNEL); 658 if (iter == NULL) 659 return -ENOMEM; 660 661 err = seq_open(file, &ddebug_proc_seqops); 662 if (err) { 663 kfree(iter); 664 return err; 665 } 666 ((struct seq_file *) file->private_data)->private = iter; 667 return 0; 668 } 669 670 static const struct file_operations ddebug_proc_fops = { 671 .owner = THIS_MODULE, 672 .open = ddebug_proc_open, 673 .read = seq_read, 674 .llseek = seq_lseek, 675 .release = seq_release_private, 676 .write = ddebug_proc_write 677 }; 678 679 /* 680 * Allocate a new ddebug_table for the given module 681 * and add it to the global list. 682 */ 683 int ddebug_add_module(struct _ddebug *tab, unsigned int n, 684 const char *name) 685 { 686 struct ddebug_table *dt; 687 char *new_name; 688 689 dt = kzalloc(sizeof(*dt), GFP_KERNEL); 690 if (dt == NULL) 691 return -ENOMEM; 692 new_name = kstrdup(name, GFP_KERNEL); 693 if (new_name == NULL) { 694 kfree(dt); 695 return -ENOMEM; 696 } 697 dt->mod_name = new_name; 698 dt->num_ddebugs = n; 699 dt->num_enabled = 0; 700 dt->ddebugs = tab; 701 702 mutex_lock(&ddebug_lock); 703 list_add_tail(&dt->link, &ddebug_tables); 704 mutex_unlock(&ddebug_lock); 705 706 if (verbose) 707 printk(KERN_INFO "%u debug prints in module %s\n", 708 n, dt->mod_name); 709 return 0; 710 } 711 EXPORT_SYMBOL_GPL(ddebug_add_module); 712 713 static void ddebug_table_free(struct ddebug_table *dt) 714 { 715 list_del_init(&dt->link); 716 kfree(dt->mod_name); 717 kfree(dt); 718 } 719 720 /* 721 * Called in response to a module being unloaded. Removes 722 * any ddebug_table's which point at the module. 723 */ 724 int ddebug_remove_module(const char *mod_name) 725 { 726 struct ddebug_table *dt, *nextdt; 727 int ret = -ENOENT; 728 729 if (verbose) 730 printk(KERN_INFO "%s: removing module \"%s\"\n", 731 __func__, mod_name); 732 733 mutex_lock(&ddebug_lock); 734 list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) { 735 if (!strcmp(dt->mod_name, mod_name)) { 736 ddebug_table_free(dt); 737 ret = 0; 738 } 739 } 740 mutex_unlock(&ddebug_lock); 741 return ret; 742 } 743 EXPORT_SYMBOL_GPL(ddebug_remove_module); 744 745 static void ddebug_remove_all_tables(void) 746 { 747 mutex_lock(&ddebug_lock); 748 while (!list_empty(&ddebug_tables)) { 749 struct ddebug_table *dt = list_entry(ddebug_tables.next, 750 struct ddebug_table, 751 link); 752 ddebug_table_free(dt); 753 } 754 mutex_unlock(&ddebug_lock); 755 } 756 757 static __initdata int ddebug_init_success; 758 759 static int __init dynamic_debug_init_debugfs(void) 760 { 761 struct dentry *dir, *file; 762 763 if (!ddebug_init_success) 764 return -ENODEV; 765 766 dir = debugfs_create_dir("dynamic_debug", NULL); 767 if (!dir) 768 return -ENOMEM; 769 file = debugfs_create_file("control", 0644, dir, NULL, 770 &ddebug_proc_fops); 771 if (!file) { 772 debugfs_remove(dir); 773 return -ENOMEM; 774 } 775 return 0; 776 } 777 778 static int __init dynamic_debug_init(void) 779 { 780 struct _ddebug *iter, *iter_start; 781 const char *modname = NULL; 782 int ret = 0; 783 int n = 0; 784 785 if (__start___verbose != __stop___verbose) { 786 iter = __start___verbose; 787 modname = iter->modname; 788 iter_start = iter; 789 for (; iter < __stop___verbose; iter++) { 790 if (strcmp(modname, iter->modname)) { 791 ret = ddebug_add_module(iter_start, n, modname); 792 if (ret) 793 goto out_free; 794 n = 0; 795 modname = iter->modname; 796 iter_start = iter; 797 } 798 n++; 799 } 800 ret = ddebug_add_module(iter_start, n, modname); 801 } 802 803 /* ddebug_query boot param got passed -> set it up */ 804 if (ddebug_setup_string[0] != '\0') { 805 ret = ddebug_exec_query(ddebug_setup_string); 806 if (ret) 807 pr_warning("Invalid ddebug boot param %s", 808 ddebug_setup_string); 809 else 810 pr_info("ddebug initialized with string %s", 811 ddebug_setup_string); 812 } 813 814 out_free: 815 if (ret) 816 ddebug_remove_all_tables(); 817 else 818 ddebug_init_success = 1; 819 return 0; 820 } 821 /* Allow early initialization for boot messages via boot param */ 822 arch_initcall(dynamic_debug_init); 823 /* Debugfs setup must be done later */ 824 module_init(dynamic_debug_init_debugfs); 825