1 /* Helpers for initial module or kernel cmdline parsing 2 Copyright (C) 2001 Rusty Russell. 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 as published by 6 the Free Software Foundation; either version 2 of the License, or 7 (at your option) any later version. 8 9 This program is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU General Public License for more details. 13 14 You should have received a copy of the GNU General Public License 15 along with this program; if not, write to the Free Software 16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 17 */ 18 #include <linux/module.h> 19 #include <linux/kernel.h> 20 #include <linux/string.h> 21 #include <linux/errno.h> 22 #include <linux/module.h> 23 #include <linux/device.h> 24 #include <linux/err.h> 25 #include <linux/slab.h> 26 #include <linux/ctype.h> 27 28 #if 0 29 #define DEBUGP printk 30 #else 31 #define DEBUGP(fmt, a...) 32 #endif 33 34 /* Protects all parameters, and incidentally kmalloced_param list. */ 35 static DEFINE_MUTEX(param_lock); 36 37 /* This just allows us to keep track of which parameters are kmalloced. */ 38 struct kmalloced_param { 39 struct list_head list; 40 char val[]; 41 }; 42 static LIST_HEAD(kmalloced_params); 43 44 static void *kmalloc_parameter(unsigned int size) 45 { 46 struct kmalloced_param *p; 47 48 p = kmalloc(sizeof(*p) + size, GFP_KERNEL); 49 if (!p) 50 return NULL; 51 52 list_add(&p->list, &kmalloced_params); 53 return p->val; 54 } 55 56 /* Does nothing if parameter wasn't kmalloced above. */ 57 static void maybe_kfree_parameter(void *param) 58 { 59 struct kmalloced_param *p; 60 61 list_for_each_entry(p, &kmalloced_params, list) { 62 if (p->val == param) { 63 list_del(&p->list); 64 kfree(p); 65 break; 66 } 67 } 68 } 69 70 static char dash2underscore(char c) 71 { 72 if (c == '-') 73 return '_'; 74 return c; 75 } 76 77 bool parameqn(const char *a, const char *b, size_t n) 78 { 79 size_t i; 80 81 for (i = 0; i < n; i++) { 82 if (dash2underscore(a[i]) != dash2underscore(b[i])) 83 return false; 84 } 85 return true; 86 } 87 88 bool parameq(const char *a, const char *b) 89 { 90 return parameqn(a, b, strlen(a)+1); 91 } 92 93 static int parse_one(char *param, 94 char *val, 95 const struct kernel_param *params, 96 unsigned num_params, 97 int (*handle_unknown)(char *param, char *val)) 98 { 99 unsigned int i; 100 int err; 101 102 /* Find parameter */ 103 for (i = 0; i < num_params; i++) { 104 if (parameq(param, params[i].name)) { 105 /* No one handled NULL, so do it here. */ 106 if (!val && params[i].ops->set != param_set_bool) 107 return -EINVAL; 108 DEBUGP("They are equal! Calling %p\n", 109 params[i].ops->set); 110 mutex_lock(¶m_lock); 111 err = params[i].ops->set(val, ¶ms[i]); 112 mutex_unlock(¶m_lock); 113 return err; 114 } 115 } 116 117 if (handle_unknown) { 118 DEBUGP("Unknown argument: calling %p\n", handle_unknown); 119 return handle_unknown(param, val); 120 } 121 122 DEBUGP("Unknown argument `%s'\n", param); 123 return -ENOENT; 124 } 125 126 /* You can use " around spaces, but can't escape ". */ 127 /* Hyphens and underscores equivalent in parameter names. */ 128 static char *next_arg(char *args, char **param, char **val) 129 { 130 unsigned int i, equals = 0; 131 int in_quote = 0, quoted = 0; 132 char *next; 133 134 if (*args == '"') { 135 args++; 136 in_quote = 1; 137 quoted = 1; 138 } 139 140 for (i = 0; args[i]; i++) { 141 if (isspace(args[i]) && !in_quote) 142 break; 143 if (equals == 0) { 144 if (args[i] == '=') 145 equals = i; 146 } 147 if (args[i] == '"') 148 in_quote = !in_quote; 149 } 150 151 *param = args; 152 if (!equals) 153 *val = NULL; 154 else { 155 args[equals] = '\0'; 156 *val = args + equals + 1; 157 158 /* Don't include quotes in value. */ 159 if (**val == '"') { 160 (*val)++; 161 if (args[i-1] == '"') 162 args[i-1] = '\0'; 163 } 164 if (quoted && args[i-1] == '"') 165 args[i-1] = '\0'; 166 } 167 168 if (args[i]) { 169 args[i] = '\0'; 170 next = args + i + 1; 171 } else 172 next = args + i; 173 174 /* Chew up trailing spaces. */ 175 return skip_spaces(next); 176 } 177 178 /* Args looks like "foo=bar,bar2 baz=fuz wiz". */ 179 int parse_args(const char *name, 180 char *args, 181 const struct kernel_param *params, 182 unsigned num, 183 int (*unknown)(char *param, char *val)) 184 { 185 char *param, *val; 186 187 DEBUGP("Parsing ARGS: %s\n", args); 188 189 /* Chew leading spaces */ 190 args = skip_spaces(args); 191 192 while (*args) { 193 int ret; 194 int irq_was_disabled; 195 196 args = next_arg(args, ¶m, &val); 197 irq_was_disabled = irqs_disabled(); 198 ret = parse_one(param, val, params, num, unknown); 199 if (irq_was_disabled && !irqs_disabled()) { 200 printk(KERN_WARNING "parse_args(): option '%s' enabled " 201 "irq's!\n", param); 202 } 203 switch (ret) { 204 case -ENOENT: 205 printk(KERN_ERR "%s: Unknown parameter `%s'\n", 206 name, param); 207 return ret; 208 case -ENOSPC: 209 printk(KERN_ERR 210 "%s: `%s' too large for parameter `%s'\n", 211 name, val ?: "", param); 212 return ret; 213 case 0: 214 break; 215 default: 216 printk(KERN_ERR 217 "%s: `%s' invalid for parameter `%s'\n", 218 name, val ?: "", param); 219 return ret; 220 } 221 } 222 223 /* All parsed OK. */ 224 return 0; 225 } 226 227 /* Lazy bastard, eh? */ 228 #define STANDARD_PARAM_DEF(name, type, format, tmptype, strtolfn) \ 229 int param_set_##name(const char *val, const struct kernel_param *kp) \ 230 { \ 231 tmptype l; \ 232 int ret; \ 233 \ 234 ret = strtolfn(val, 0, &l); \ 235 if (ret < 0 || ((type)l != l)) \ 236 return ret < 0 ? ret : -EINVAL; \ 237 *((type *)kp->arg) = l; \ 238 return 0; \ 239 } \ 240 int param_get_##name(char *buffer, const struct kernel_param *kp) \ 241 { \ 242 return sprintf(buffer, format, *((type *)kp->arg)); \ 243 } \ 244 struct kernel_param_ops param_ops_##name = { \ 245 .set = param_set_##name, \ 246 .get = param_get_##name, \ 247 }; \ 248 EXPORT_SYMBOL(param_set_##name); \ 249 EXPORT_SYMBOL(param_get_##name); \ 250 EXPORT_SYMBOL(param_ops_##name) 251 252 253 STANDARD_PARAM_DEF(byte, unsigned char, "%c", unsigned long, strict_strtoul); 254 STANDARD_PARAM_DEF(short, short, "%hi", long, strict_strtol); 255 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, strict_strtoul); 256 STANDARD_PARAM_DEF(int, int, "%i", long, strict_strtol); 257 STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, strict_strtoul); 258 STANDARD_PARAM_DEF(long, long, "%li", long, strict_strtol); 259 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul); 260 261 int param_set_charp(const char *val, const struct kernel_param *kp) 262 { 263 if (strlen(val) > 1024) { 264 printk(KERN_ERR "%s: string parameter too long\n", 265 kp->name); 266 return -ENOSPC; 267 } 268 269 maybe_kfree_parameter(*(char **)kp->arg); 270 271 /* This is a hack. We can't kmalloc in early boot, and we 272 * don't need to; this mangled commandline is preserved. */ 273 if (slab_is_available()) { 274 *(char **)kp->arg = kmalloc_parameter(strlen(val)+1); 275 if (!*(char **)kp->arg) 276 return -ENOMEM; 277 strcpy(*(char **)kp->arg, val); 278 } else 279 *(const char **)kp->arg = val; 280 281 return 0; 282 } 283 EXPORT_SYMBOL(param_set_charp); 284 285 int param_get_charp(char *buffer, const struct kernel_param *kp) 286 { 287 return sprintf(buffer, "%s", *((char **)kp->arg)); 288 } 289 EXPORT_SYMBOL(param_get_charp); 290 291 static void param_free_charp(void *arg) 292 { 293 maybe_kfree_parameter(*((char **)arg)); 294 } 295 296 struct kernel_param_ops param_ops_charp = { 297 .set = param_set_charp, 298 .get = param_get_charp, 299 .free = param_free_charp, 300 }; 301 EXPORT_SYMBOL(param_ops_charp); 302 303 /* Actually could be a bool or an int, for historical reasons. */ 304 int param_set_bool(const char *val, const struct kernel_param *kp) 305 { 306 bool v; 307 int ret; 308 309 /* No equals means "set"... */ 310 if (!val) val = "1"; 311 312 /* One of =[yYnN01] */ 313 ret = strtobool(val, &v); 314 if (ret) 315 return ret; 316 317 if (kp->flags & KPARAM_ISBOOL) 318 *(bool *)kp->arg = v; 319 else 320 *(int *)kp->arg = v; 321 return 0; 322 } 323 EXPORT_SYMBOL(param_set_bool); 324 325 int param_get_bool(char *buffer, const struct kernel_param *kp) 326 { 327 bool val; 328 if (kp->flags & KPARAM_ISBOOL) 329 val = *(bool *)kp->arg; 330 else 331 val = *(int *)kp->arg; 332 333 /* Y and N chosen as being relatively non-coder friendly */ 334 return sprintf(buffer, "%c", val ? 'Y' : 'N'); 335 } 336 EXPORT_SYMBOL(param_get_bool); 337 338 struct kernel_param_ops param_ops_bool = { 339 .set = param_set_bool, 340 .get = param_get_bool, 341 }; 342 EXPORT_SYMBOL(param_ops_bool); 343 344 /* This one must be bool. */ 345 int param_set_invbool(const char *val, const struct kernel_param *kp) 346 { 347 int ret; 348 bool boolval; 349 struct kernel_param dummy; 350 351 dummy.arg = &boolval; 352 dummy.flags = KPARAM_ISBOOL; 353 ret = param_set_bool(val, &dummy); 354 if (ret == 0) 355 *(bool *)kp->arg = !boolval; 356 return ret; 357 } 358 EXPORT_SYMBOL(param_set_invbool); 359 360 int param_get_invbool(char *buffer, const struct kernel_param *kp) 361 { 362 return sprintf(buffer, "%c", (*(bool *)kp->arg) ? 'N' : 'Y'); 363 } 364 EXPORT_SYMBOL(param_get_invbool); 365 366 struct kernel_param_ops param_ops_invbool = { 367 .set = param_set_invbool, 368 .get = param_get_invbool, 369 }; 370 EXPORT_SYMBOL(param_ops_invbool); 371 372 /* We break the rule and mangle the string. */ 373 static int param_array(const char *name, 374 const char *val, 375 unsigned int min, unsigned int max, 376 void *elem, int elemsize, 377 int (*set)(const char *, const struct kernel_param *kp), 378 u16 flags, 379 unsigned int *num) 380 { 381 int ret; 382 struct kernel_param kp; 383 char save; 384 385 /* Get the name right for errors. */ 386 kp.name = name; 387 kp.arg = elem; 388 kp.flags = flags; 389 390 *num = 0; 391 /* We expect a comma-separated list of values. */ 392 do { 393 int len; 394 395 if (*num == max) { 396 printk(KERN_ERR "%s: can only take %i arguments\n", 397 name, max); 398 return -EINVAL; 399 } 400 len = strcspn(val, ","); 401 402 /* nul-terminate and parse */ 403 save = val[len]; 404 ((char *)val)[len] = '\0'; 405 BUG_ON(!mutex_is_locked(¶m_lock)); 406 ret = set(val, &kp); 407 408 if (ret != 0) 409 return ret; 410 kp.arg += elemsize; 411 val += len+1; 412 (*num)++; 413 } while (save == ','); 414 415 if (*num < min) { 416 printk(KERN_ERR "%s: needs at least %i arguments\n", 417 name, min); 418 return -EINVAL; 419 } 420 return 0; 421 } 422 423 static int param_array_set(const char *val, const struct kernel_param *kp) 424 { 425 const struct kparam_array *arr = kp->arr; 426 unsigned int temp_num; 427 428 return param_array(kp->name, val, 1, arr->max, arr->elem, 429 arr->elemsize, arr->ops->set, kp->flags, 430 arr->num ?: &temp_num); 431 } 432 433 static int param_array_get(char *buffer, const struct kernel_param *kp) 434 { 435 int i, off, ret; 436 const struct kparam_array *arr = kp->arr; 437 struct kernel_param p; 438 439 p = *kp; 440 for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) { 441 if (i) 442 buffer[off++] = ','; 443 p.arg = arr->elem + arr->elemsize * i; 444 BUG_ON(!mutex_is_locked(¶m_lock)); 445 ret = arr->ops->get(buffer + off, &p); 446 if (ret < 0) 447 return ret; 448 off += ret; 449 } 450 buffer[off] = '\0'; 451 return off; 452 } 453 454 static void param_array_free(void *arg) 455 { 456 unsigned int i; 457 const struct kparam_array *arr = arg; 458 459 if (arr->ops->free) 460 for (i = 0; i < (arr->num ? *arr->num : arr->max); i++) 461 arr->ops->free(arr->elem + arr->elemsize * i); 462 } 463 464 struct kernel_param_ops param_array_ops = { 465 .set = param_array_set, 466 .get = param_array_get, 467 .free = param_array_free, 468 }; 469 EXPORT_SYMBOL(param_array_ops); 470 471 int param_set_copystring(const char *val, const struct kernel_param *kp) 472 { 473 const struct kparam_string *kps = kp->str; 474 475 if (strlen(val)+1 > kps->maxlen) { 476 printk(KERN_ERR "%s: string doesn't fit in %u chars.\n", 477 kp->name, kps->maxlen-1); 478 return -ENOSPC; 479 } 480 strcpy(kps->string, val); 481 return 0; 482 } 483 EXPORT_SYMBOL(param_set_copystring); 484 485 int param_get_string(char *buffer, const struct kernel_param *kp) 486 { 487 const struct kparam_string *kps = kp->str; 488 return strlcpy(buffer, kps->string, kps->maxlen); 489 } 490 EXPORT_SYMBOL(param_get_string); 491 492 struct kernel_param_ops param_ops_string = { 493 .set = param_set_copystring, 494 .get = param_get_string, 495 }; 496 EXPORT_SYMBOL(param_ops_string); 497 498 /* sysfs output in /sys/modules/XYZ/parameters/ */ 499 #define to_module_attr(n) container_of(n, struct module_attribute, attr) 500 #define to_module_kobject(n) container_of(n, struct module_kobject, kobj) 501 502 extern struct kernel_param __start___param[], __stop___param[]; 503 504 struct param_attribute 505 { 506 struct module_attribute mattr; 507 const struct kernel_param *param; 508 }; 509 510 struct module_param_attrs 511 { 512 unsigned int num; 513 struct attribute_group grp; 514 struct param_attribute attrs[0]; 515 }; 516 517 #ifdef CONFIG_SYSFS 518 #define to_param_attr(n) container_of(n, struct param_attribute, mattr) 519 520 static ssize_t param_attr_show(struct module_attribute *mattr, 521 struct module_kobject *mk, char *buf) 522 { 523 int count; 524 struct param_attribute *attribute = to_param_attr(mattr); 525 526 if (!attribute->param->ops->get) 527 return -EPERM; 528 529 mutex_lock(¶m_lock); 530 count = attribute->param->ops->get(buf, attribute->param); 531 mutex_unlock(¶m_lock); 532 if (count > 0) { 533 strcat(buf, "\n"); 534 ++count; 535 } 536 return count; 537 } 538 539 /* sysfs always hands a nul-terminated string in buf. We rely on that. */ 540 static ssize_t param_attr_store(struct module_attribute *mattr, 541 struct module_kobject *km, 542 const char *buf, size_t len) 543 { 544 int err; 545 struct param_attribute *attribute = to_param_attr(mattr); 546 547 if (!attribute->param->ops->set) 548 return -EPERM; 549 550 mutex_lock(¶m_lock); 551 err = attribute->param->ops->set(buf, attribute->param); 552 mutex_unlock(¶m_lock); 553 if (!err) 554 return len; 555 return err; 556 } 557 #endif 558 559 #ifdef CONFIG_MODULES 560 #define __modinit 561 #else 562 #define __modinit __init 563 #endif 564 565 #ifdef CONFIG_SYSFS 566 void __kernel_param_lock(void) 567 { 568 mutex_lock(¶m_lock); 569 } 570 EXPORT_SYMBOL(__kernel_param_lock); 571 572 void __kernel_param_unlock(void) 573 { 574 mutex_unlock(¶m_lock); 575 } 576 EXPORT_SYMBOL(__kernel_param_unlock); 577 578 /* 579 * add_sysfs_param - add a parameter to sysfs 580 * @mk: struct module_kobject 581 * @kparam: the actual parameter definition to add to sysfs 582 * @name: name of parameter 583 * 584 * Create a kobject if for a (per-module) parameter if mp NULL, and 585 * create file in sysfs. Returns an error on out of memory. Always cleans up 586 * if there's an error. 587 */ 588 static __modinit int add_sysfs_param(struct module_kobject *mk, 589 const struct kernel_param *kp, 590 const char *name) 591 { 592 struct module_param_attrs *new; 593 struct attribute **attrs; 594 int err, num; 595 596 /* We don't bother calling this with invisible parameters. */ 597 BUG_ON(!kp->perm); 598 599 if (!mk->mp) { 600 num = 0; 601 attrs = NULL; 602 } else { 603 num = mk->mp->num; 604 attrs = mk->mp->grp.attrs; 605 } 606 607 /* Enlarge. */ 608 new = krealloc(mk->mp, 609 sizeof(*mk->mp) + sizeof(mk->mp->attrs[0]) * (num+1), 610 GFP_KERNEL); 611 if (!new) { 612 kfree(mk->mp); 613 err = -ENOMEM; 614 goto fail; 615 } 616 attrs = krealloc(attrs, sizeof(new->grp.attrs[0])*(num+2), GFP_KERNEL); 617 if (!attrs) { 618 err = -ENOMEM; 619 goto fail_free_new; 620 } 621 622 /* Sysfs wants everything zeroed. */ 623 memset(new, 0, sizeof(*new)); 624 memset(&new->attrs[num], 0, sizeof(new->attrs[num])); 625 memset(&attrs[num], 0, sizeof(attrs[num])); 626 new->grp.name = "parameters"; 627 new->grp.attrs = attrs; 628 629 /* Tack new one on the end. */ 630 sysfs_attr_init(&new->attrs[num].mattr.attr); 631 new->attrs[num].param = kp; 632 new->attrs[num].mattr.show = param_attr_show; 633 new->attrs[num].mattr.store = param_attr_store; 634 new->attrs[num].mattr.attr.name = (char *)name; 635 new->attrs[num].mattr.attr.mode = kp->perm; 636 new->num = num+1; 637 638 /* Fix up all the pointers, since krealloc can move us */ 639 for (num = 0; num < new->num; num++) 640 new->grp.attrs[num] = &new->attrs[num].mattr.attr; 641 new->grp.attrs[num] = NULL; 642 643 mk->mp = new; 644 return 0; 645 646 fail_free_new: 647 kfree(new); 648 fail: 649 mk->mp = NULL; 650 return err; 651 } 652 653 #ifdef CONFIG_MODULES 654 static void free_module_param_attrs(struct module_kobject *mk) 655 { 656 kfree(mk->mp->grp.attrs); 657 kfree(mk->mp); 658 mk->mp = NULL; 659 } 660 661 /* 662 * module_param_sysfs_setup - setup sysfs support for one module 663 * @mod: module 664 * @kparam: module parameters (array) 665 * @num_params: number of module parameters 666 * 667 * Adds sysfs entries for module parameters under 668 * /sys/module/[mod->name]/parameters/ 669 */ 670 int module_param_sysfs_setup(struct module *mod, 671 const struct kernel_param *kparam, 672 unsigned int num_params) 673 { 674 int i, err; 675 bool params = false; 676 677 for (i = 0; i < num_params; i++) { 678 if (kparam[i].perm == 0) 679 continue; 680 err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name); 681 if (err) 682 return err; 683 params = true; 684 } 685 686 if (!params) 687 return 0; 688 689 /* Create the param group. */ 690 err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp); 691 if (err) 692 free_module_param_attrs(&mod->mkobj); 693 return err; 694 } 695 696 /* 697 * module_param_sysfs_remove - remove sysfs support for one module 698 * @mod: module 699 * 700 * Remove sysfs entries for module parameters and the corresponding 701 * kobject. 702 */ 703 void module_param_sysfs_remove(struct module *mod) 704 { 705 if (mod->mkobj.mp) { 706 sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp); 707 /* We are positive that no one is using any param 708 * attrs at this point. Deallocate immediately. */ 709 free_module_param_attrs(&mod->mkobj); 710 } 711 } 712 #endif 713 714 void destroy_params(const struct kernel_param *params, unsigned num) 715 { 716 unsigned int i; 717 718 for (i = 0; i < num; i++) 719 if (params[i].ops->free) 720 params[i].ops->free(params[i].arg); 721 } 722 723 static struct module_kobject * __init locate_module_kobject(const char *name) 724 { 725 struct module_kobject *mk; 726 struct kobject *kobj; 727 int err; 728 729 kobj = kset_find_obj(module_kset, name); 730 if (kobj) { 731 mk = to_module_kobject(kobj); 732 } else { 733 mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL); 734 BUG_ON(!mk); 735 736 mk->mod = THIS_MODULE; 737 mk->kobj.kset = module_kset; 738 err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL, 739 "%s", name); 740 #ifdef CONFIG_MODULES 741 if (!err) 742 err = sysfs_create_file(&mk->kobj, &module_uevent.attr); 743 #endif 744 if (err) { 745 kobject_put(&mk->kobj); 746 printk(KERN_ERR 747 "Module '%s' failed add to sysfs, error number %d\n", 748 name, err); 749 printk(KERN_ERR 750 "The system will be unstable now.\n"); 751 return NULL; 752 } 753 754 /* So that we hold reference in both cases. */ 755 kobject_get(&mk->kobj); 756 } 757 758 return mk; 759 } 760 761 static void __init kernel_add_sysfs_param(const char *name, 762 struct kernel_param *kparam, 763 unsigned int name_skip) 764 { 765 struct module_kobject *mk; 766 int err; 767 768 mk = locate_module_kobject(name); 769 if (!mk) 770 return; 771 772 /* We need to remove old parameters before adding more. */ 773 if (mk->mp) 774 sysfs_remove_group(&mk->kobj, &mk->mp->grp); 775 776 /* These should not fail at boot. */ 777 err = add_sysfs_param(mk, kparam, kparam->name + name_skip); 778 BUG_ON(err); 779 err = sysfs_create_group(&mk->kobj, &mk->mp->grp); 780 BUG_ON(err); 781 kobject_uevent(&mk->kobj, KOBJ_ADD); 782 kobject_put(&mk->kobj); 783 } 784 785 /* 786 * param_sysfs_builtin - add contents in /sys/parameters for built-in modules 787 * 788 * Add module_parameters to sysfs for "modules" built into the kernel. 789 * 790 * The "module" name (KBUILD_MODNAME) is stored before a dot, the 791 * "parameter" name is stored behind a dot in kernel_param->name. So, 792 * extract the "module" name for all built-in kernel_param-eters, 793 * and for all who have the same, call kernel_add_sysfs_param. 794 */ 795 static void __init param_sysfs_builtin(void) 796 { 797 struct kernel_param *kp; 798 unsigned int name_len; 799 char modname[MODULE_NAME_LEN]; 800 801 for (kp = __start___param; kp < __stop___param; kp++) { 802 char *dot; 803 804 if (kp->perm == 0) 805 continue; 806 807 dot = strchr(kp->name, '.'); 808 if (!dot) { 809 /* This happens for core_param() */ 810 strcpy(modname, "kernel"); 811 name_len = 0; 812 } else { 813 name_len = dot - kp->name + 1; 814 strlcpy(modname, kp->name, name_len); 815 } 816 kernel_add_sysfs_param(modname, kp, name_len); 817 } 818 } 819 820 ssize_t __modver_version_show(struct module_attribute *mattr, 821 struct module_kobject *mk, char *buf) 822 { 823 struct module_version_attribute *vattr = 824 container_of(mattr, struct module_version_attribute, mattr); 825 826 return sprintf(buf, "%s\n", vattr->version); 827 } 828 829 extern const struct module_version_attribute *__start___modver[]; 830 extern const struct module_version_attribute *__stop___modver[]; 831 832 static void __init version_sysfs_builtin(void) 833 { 834 const struct module_version_attribute **p; 835 struct module_kobject *mk; 836 int err; 837 838 for (p = __start___modver; p < __stop___modver; p++) { 839 const struct module_version_attribute *vattr = *p; 840 841 mk = locate_module_kobject(vattr->module_name); 842 if (mk) { 843 err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr); 844 kobject_uevent(&mk->kobj, KOBJ_ADD); 845 kobject_put(&mk->kobj); 846 } 847 } 848 } 849 850 /* module-related sysfs stuff */ 851 852 static ssize_t module_attr_show(struct kobject *kobj, 853 struct attribute *attr, 854 char *buf) 855 { 856 struct module_attribute *attribute; 857 struct module_kobject *mk; 858 int ret; 859 860 attribute = to_module_attr(attr); 861 mk = to_module_kobject(kobj); 862 863 if (!attribute->show) 864 return -EIO; 865 866 ret = attribute->show(attribute, mk, buf); 867 868 return ret; 869 } 870 871 static ssize_t module_attr_store(struct kobject *kobj, 872 struct attribute *attr, 873 const char *buf, size_t len) 874 { 875 struct module_attribute *attribute; 876 struct module_kobject *mk; 877 int ret; 878 879 attribute = to_module_attr(attr); 880 mk = to_module_kobject(kobj); 881 882 if (!attribute->store) 883 return -EIO; 884 885 ret = attribute->store(attribute, mk, buf, len); 886 887 return ret; 888 } 889 890 static const struct sysfs_ops module_sysfs_ops = { 891 .show = module_attr_show, 892 .store = module_attr_store, 893 }; 894 895 static int uevent_filter(struct kset *kset, struct kobject *kobj) 896 { 897 struct kobj_type *ktype = get_ktype(kobj); 898 899 if (ktype == &module_ktype) 900 return 1; 901 return 0; 902 } 903 904 static const struct kset_uevent_ops module_uevent_ops = { 905 .filter = uevent_filter, 906 }; 907 908 struct kset *module_kset; 909 int module_sysfs_initialized; 910 911 struct kobj_type module_ktype = { 912 .sysfs_ops = &module_sysfs_ops, 913 }; 914 915 /* 916 * param_sysfs_init - wrapper for built-in params support 917 */ 918 static int __init param_sysfs_init(void) 919 { 920 module_kset = kset_create_and_add("module", &module_uevent_ops, NULL); 921 if (!module_kset) { 922 printk(KERN_WARNING "%s (%d): error creating kset\n", 923 __FILE__, __LINE__); 924 return -ENOMEM; 925 } 926 module_sysfs_initialized = 1; 927 928 version_sysfs_builtin(); 929 param_sysfs_builtin(); 930 931 return 0; 932 } 933 subsys_initcall(param_sysfs_init); 934 935 #endif /* CONFIG_SYSFS */ 936