| 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
| 2 | /* Helpers for initial module or kernel cmdline parsing |
| 3 | Copyright (C) 2001 Rusty Russell. |
| 4 | |
| 5 | */ |
| 6 | #include <linux/kernel.h> |
| 7 | #include <linux/string.h> |
| 8 | #include <linux/errno.h> |
| 9 | #include <linux/module.h> |
| 10 | #include <linux/moduleparam.h> |
| 11 | #include <linux/device.h> |
| 12 | #include <linux/err.h> |
| 13 | #include <linux/slab.h> |
| 14 | #include <linux/ctype.h> |
| 15 | #include <linux/security.h> |
| 16 | |
| 17 | #ifdef CONFIG_SYSFS |
| 18 | /* Protects all built-in parameters, modules use their own param_lock */ |
| 19 | static DEFINE_MUTEX(param_lock); |
| 20 | |
| 21 | /* Use the module's mutex, or if built-in use the built-in mutex */ |
| 22 | #ifdef CONFIG_MODULES |
| 23 | #define KPARAM_MUTEX(mod) ((mod) ? &(mod)->param_lock : ¶m_lock) |
| 24 | #else |
| 25 | #define KPARAM_MUTEX(mod) (¶m_lock) |
| 26 | #endif |
| 27 | |
| 28 | static inline void check_kparam_locked(struct module *mod) |
| 29 | { |
| 30 | BUG_ON(!mutex_is_locked(KPARAM_MUTEX(mod))); |
| 31 | } |
| 32 | #else |
| 33 | static inline void check_kparam_locked(struct module *mod) |
| 34 | { |
| 35 | } |
| 36 | #endif /* !CONFIG_SYSFS */ |
| 37 | |
| 38 | /* This just allows us to keep track of which parameters are kmalloced. */ |
| 39 | struct kmalloced_param { |
| 40 | struct list_head list; |
| 41 | char val[]; |
| 42 | }; |
| 43 | static LIST_HEAD(kmalloced_params); |
| 44 | static DEFINE_SPINLOCK(kmalloced_params_lock); |
| 45 | |
| 46 | static void *kmalloc_parameter(unsigned int size) |
| 47 | { |
| 48 | struct kmalloced_param *p; |
| 49 | |
| 50 | p = kmalloc(sizeof(*p) + size, GFP_KERNEL); |
| 51 | if (!p) |
| 52 | return NULL; |
| 53 | |
| 54 | spin_lock(&kmalloced_params_lock); |
| 55 | list_add(&p->list, &kmalloced_params); |
| 56 | spin_unlock(&kmalloced_params_lock); |
| 57 | |
| 58 | return p->val; |
| 59 | } |
| 60 | |
| 61 | /* Does nothing if parameter wasn't kmalloced above. */ |
| 62 | static void maybe_kfree_parameter(void *param) |
| 63 | { |
| 64 | struct kmalloced_param *p; |
| 65 | |
| 66 | spin_lock(&kmalloced_params_lock); |
| 67 | list_for_each_entry(p, &kmalloced_params, list) { |
| 68 | if (p->val == param) { |
| 69 | list_del(&p->list); |
| 70 | kfree(p); |
| 71 | break; |
| 72 | } |
| 73 | } |
| 74 | spin_unlock(&kmalloced_params_lock); |
| 75 | } |
| 76 | |
| 77 | static char dash2underscore(char c) |
| 78 | { |
| 79 | if (c == '-') |
| 80 | return '_'; |
| 81 | return c; |
| 82 | } |
| 83 | |
| 84 | bool parameqn(const char *a, const char *b, size_t n) |
| 85 | { |
| 86 | size_t i; |
| 87 | |
| 88 | for (i = 0; i < n; i++) { |
| 89 | if (dash2underscore(a[i]) != dash2underscore(b[i])) |
| 90 | return false; |
| 91 | } |
| 92 | return true; |
| 93 | } |
| 94 | |
| 95 | bool parameq(const char *a, const char *b) |
| 96 | { |
| 97 | return parameqn(a, b, strlen(a)+1); |
| 98 | } |
| 99 | |
| 100 | static bool param_check_unsafe(const struct kernel_param *kp) |
| 101 | { |
| 102 | if (kp->flags & KERNEL_PARAM_FL_HWPARAM && |
| 103 | security_locked_down(LOCKDOWN_MODULE_PARAMETERS)) |
| 104 | return false; |
| 105 | |
| 106 | if (kp->flags & KERNEL_PARAM_FL_UNSAFE) { |
| 107 | pr_notice("Setting dangerous option %s - tainting kernel\n", |
| 108 | kp->name); |
| 109 | add_taint(TAINT_USER, LOCKDEP_STILL_OK); |
| 110 | } |
| 111 | |
| 112 | return true; |
| 113 | } |
| 114 | |
| 115 | static int parse_one(char *param, |
| 116 | char *val, |
| 117 | const char *doing, |
| 118 | const struct kernel_param *params, |
| 119 | unsigned num_params, |
| 120 | s16 min_level, |
| 121 | s16 max_level, |
| 122 | void *arg, |
| 123 | int (*handle_unknown)(char *param, char *val, |
| 124 | const char *doing, void *arg)) |
| 125 | { |
| 126 | unsigned int i; |
| 127 | int err; |
| 128 | |
| 129 | /* Find parameter */ |
| 130 | for (i = 0; i < num_params; i++) { |
| 131 | if (parameq(param, params[i].name)) { |
| 132 | if (params[i].level < min_level |
| 133 | || params[i].level > max_level) |
| 134 | return 0; |
| 135 | /* No one handled NULL, so do it here. */ |
| 136 | if (!val && |
| 137 | !(params[i].ops->flags & KERNEL_PARAM_OPS_FL_NOARG)) |
| 138 | return -EINVAL; |
| 139 | pr_debug("handling %s with %p\n", param, |
| 140 | params[i].ops->set); |
| 141 | kernel_param_lock(params[i].mod); |
| 142 | if (param_check_unsafe(¶ms[i])) |
| 143 | err = params[i].ops->set(val, ¶ms[i]); |
| 144 | else |
| 145 | err = -EPERM; |
| 146 | kernel_param_unlock(params[i].mod); |
| 147 | return err; |
| 148 | } |
| 149 | } |
| 150 | |
| 151 | if (handle_unknown) { |
| 152 | pr_debug("doing %s: %s='%s'\n", doing, param, val); |
| 153 | return handle_unknown(param, val, doing, arg); |
| 154 | } |
| 155 | |
| 156 | pr_debug("Unknown argument '%s'\n", param); |
| 157 | return -ENOENT; |
| 158 | } |
| 159 | |
| 160 | /* Args looks like "foo=bar,bar2 baz=fuz wiz". */ |
| 161 | char *parse_args(const char *doing, |
| 162 | char *args, |
| 163 | const struct kernel_param *params, |
| 164 | unsigned num, |
| 165 | s16 min_level, |
| 166 | s16 max_level, |
| 167 | void *arg, |
| 168 | int (*unknown)(char *param, char *val, |
| 169 | const char *doing, void *arg)) |
| 170 | { |
| 171 | char *param, *val, *err = NULL; |
| 172 | |
| 173 | /* Chew leading spaces */ |
| 174 | args = skip_spaces(args); |
| 175 | |
| 176 | if (*args) |
| 177 | pr_debug("doing %s, parsing ARGS: '%s'\n", doing, args); |
| 178 | |
| 179 | while (*args) { |
| 180 | int ret; |
| 181 | int irq_was_disabled; |
| 182 | |
| 183 | args = next_arg(args, ¶m, &val); |
| 184 | /* Stop at -- */ |
| 185 | if (!val && strcmp(param, "--") == 0) |
| 186 | return err ?: args; |
| 187 | irq_was_disabled = irqs_disabled(); |
| 188 | ret = parse_one(param, val, doing, params, num, |
| 189 | min_level, max_level, arg, unknown); |
| 190 | if (irq_was_disabled && !irqs_disabled()) |
| 191 | pr_warn("%s: option '%s' enabled irq's!\n", |
| 192 | doing, param); |
| 193 | |
| 194 | switch (ret) { |
| 195 | case 0: |
| 196 | continue; |
| 197 | case -ENOENT: |
| 198 | pr_err("%s: Unknown parameter `%s'\n", doing, param); |
| 199 | break; |
| 200 | case -ENOSPC: |
| 201 | pr_err("%s: `%s' too large for parameter `%s'\n", |
| 202 | doing, val ?: "", param); |
| 203 | break; |
| 204 | default: |
| 205 | pr_err("%s: `%s' invalid for parameter `%s'\n", |
| 206 | doing, val ?: "", param); |
| 207 | break; |
| 208 | } |
| 209 | |
| 210 | err = ERR_PTR(ret); |
| 211 | } |
| 212 | |
| 213 | return err; |
| 214 | } |
| 215 | |
| 216 | /* Lazy bastard, eh? */ |
| 217 | #define STANDARD_PARAM_DEF(name, type, format, strtolfn) \ |
| 218 | int param_set_##name(const char *val, const struct kernel_param *kp) \ |
| 219 | { \ |
| 220 | return strtolfn(val, 0, (type *)kp->arg); \ |
| 221 | } \ |
| 222 | int param_get_##name(char *buffer, const struct kernel_param *kp) \ |
| 223 | { \ |
| 224 | return scnprintf(buffer, PAGE_SIZE, format "\n", \ |
| 225 | *((type *)kp->arg)); \ |
| 226 | } \ |
| 227 | const struct kernel_param_ops param_ops_##name = { \ |
| 228 | .set = param_set_##name, \ |
| 229 | .get = param_get_##name, \ |
| 230 | }; \ |
| 231 | EXPORT_SYMBOL(param_set_##name); \ |
| 232 | EXPORT_SYMBOL(param_get_##name); \ |
| 233 | EXPORT_SYMBOL(param_ops_##name) |
| 234 | |
| 235 | |
| 236 | STANDARD_PARAM_DEF(byte, unsigned char, "%hhu", kstrtou8); |
| 237 | STANDARD_PARAM_DEF(short, short, "%hi", kstrtos16); |
| 238 | STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", kstrtou16); |
| 239 | STANDARD_PARAM_DEF(int, int, "%i", kstrtoint); |
| 240 | STANDARD_PARAM_DEF(uint, unsigned int, "%u", kstrtouint); |
| 241 | STANDARD_PARAM_DEF(long, long, "%li", kstrtol); |
| 242 | STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", kstrtoul); |
| 243 | STANDARD_PARAM_DEF(ullong, unsigned long long, "%llu", kstrtoull); |
| 244 | STANDARD_PARAM_DEF(hexint, unsigned int, "%#08x", kstrtouint); |
| 245 | |
| 246 | int param_set_uint_minmax(const char *val, const struct kernel_param *kp, |
| 247 | unsigned int min, unsigned int max) |
| 248 | { |
| 249 | unsigned int num; |
| 250 | int ret; |
| 251 | |
| 252 | if (!val) |
| 253 | return -EINVAL; |
| 254 | ret = kstrtouint(val, 0, &num); |
| 255 | if (ret) |
| 256 | return ret; |
| 257 | if (num < min || num > max) |
| 258 | return -EINVAL; |
| 259 | *((unsigned int *)kp->arg) = num; |
| 260 | return 0; |
| 261 | } |
| 262 | EXPORT_SYMBOL_GPL(param_set_uint_minmax); |
| 263 | |
| 264 | int param_set_charp(const char *val, const struct kernel_param *kp) |
| 265 | { |
| 266 | if (strlen(val) > 1024) { |
| 267 | pr_err("%s: string parameter too long\n", kp->name); |
| 268 | return -ENOSPC; |
| 269 | } |
| 270 | |
| 271 | maybe_kfree_parameter(*(char **)kp->arg); |
| 272 | |
| 273 | /* This is a hack. We can't kmalloc in early boot, and we |
| 274 | * don't need to; this mangled commandline is preserved. */ |
| 275 | if (slab_is_available()) { |
| 276 | *(char **)kp->arg = kmalloc_parameter(strlen(val)+1); |
| 277 | if (!*(char **)kp->arg) |
| 278 | return -ENOMEM; |
| 279 | strcpy(*(char **)kp->arg, val); |
| 280 | } else |
| 281 | *(const char **)kp->arg = val; |
| 282 | |
| 283 | return 0; |
| 284 | } |
| 285 | EXPORT_SYMBOL(param_set_charp); |
| 286 | |
| 287 | int param_get_charp(char *buffer, const struct kernel_param *kp) |
| 288 | { |
| 289 | return scnprintf(buffer, PAGE_SIZE, "%s\n", *((char **)kp->arg)); |
| 290 | } |
| 291 | EXPORT_SYMBOL(param_get_charp); |
| 292 | |
| 293 | void param_free_charp(void *arg) |
| 294 | { |
| 295 | maybe_kfree_parameter(*((char **)arg)); |
| 296 | } |
| 297 | EXPORT_SYMBOL(param_free_charp); |
| 298 | |
| 299 | const struct kernel_param_ops param_ops_charp = { |
| 300 | .set = param_set_charp, |
| 301 | .get = param_get_charp, |
| 302 | .free = param_free_charp, |
| 303 | }; |
| 304 | EXPORT_SYMBOL(param_ops_charp); |
| 305 | |
| 306 | /* Actually could be a bool or an int, for historical reasons. */ |
| 307 | int param_set_bool(const char *val, const struct kernel_param *kp) |
| 308 | { |
| 309 | /* No equals means "set"... */ |
| 310 | if (!val) val = "1"; |
| 311 | |
| 312 | /* One of =[yYnN01] */ |
| 313 | return strtobool(val, kp->arg); |
| 314 | } |
| 315 | EXPORT_SYMBOL(param_set_bool); |
| 316 | |
| 317 | int param_get_bool(char *buffer, const struct kernel_param *kp) |
| 318 | { |
| 319 | /* Y and N chosen as being relatively non-coder friendly */ |
| 320 | return sprintf(buffer, "%c\n", *(bool *)kp->arg ? 'Y' : 'N'); |
| 321 | } |
| 322 | EXPORT_SYMBOL(param_get_bool); |
| 323 | |
| 324 | const struct kernel_param_ops param_ops_bool = { |
| 325 | .flags = KERNEL_PARAM_OPS_FL_NOARG, |
| 326 | .set = param_set_bool, |
| 327 | .get = param_get_bool, |
| 328 | }; |
| 329 | EXPORT_SYMBOL(param_ops_bool); |
| 330 | |
| 331 | int param_set_bool_enable_only(const char *val, const struct kernel_param *kp) |
| 332 | { |
| 333 | int err = 0; |
| 334 | bool new_value; |
| 335 | bool orig_value = *(bool *)kp->arg; |
| 336 | struct kernel_param dummy_kp = *kp; |
| 337 | |
| 338 | dummy_kp.arg = &new_value; |
| 339 | |
| 340 | err = param_set_bool(val, &dummy_kp); |
| 341 | if (err) |
| 342 | return err; |
| 343 | |
| 344 | /* Don't let them unset it once it's set! */ |
| 345 | if (!new_value && orig_value) |
| 346 | return -EROFS; |
| 347 | |
| 348 | if (new_value) |
| 349 | err = param_set_bool(val, kp); |
| 350 | |
| 351 | return err; |
| 352 | } |
| 353 | EXPORT_SYMBOL_GPL(param_set_bool_enable_only); |
| 354 | |
| 355 | const struct kernel_param_ops param_ops_bool_enable_only = { |
| 356 | .flags = KERNEL_PARAM_OPS_FL_NOARG, |
| 357 | .set = param_set_bool_enable_only, |
| 358 | .get = param_get_bool, |
| 359 | }; |
| 360 | EXPORT_SYMBOL_GPL(param_ops_bool_enable_only); |
| 361 | |
| 362 | /* This one must be bool. */ |
| 363 | int param_set_invbool(const char *val, const struct kernel_param *kp) |
| 364 | { |
| 365 | int ret; |
| 366 | bool boolval; |
| 367 | struct kernel_param dummy; |
| 368 | |
| 369 | dummy.arg = &boolval; |
| 370 | ret = param_set_bool(val, &dummy); |
| 371 | if (ret == 0) |
| 372 | *(bool *)kp->arg = !boolval; |
| 373 | return ret; |
| 374 | } |
| 375 | EXPORT_SYMBOL(param_set_invbool); |
| 376 | |
| 377 | int param_get_invbool(char *buffer, const struct kernel_param *kp) |
| 378 | { |
| 379 | return sprintf(buffer, "%c\n", (*(bool *)kp->arg) ? 'N' : 'Y'); |
| 380 | } |
| 381 | EXPORT_SYMBOL(param_get_invbool); |
| 382 | |
| 383 | const struct kernel_param_ops param_ops_invbool = { |
| 384 | .set = param_set_invbool, |
| 385 | .get = param_get_invbool, |
| 386 | }; |
| 387 | EXPORT_SYMBOL(param_ops_invbool); |
| 388 | |
| 389 | int param_set_bint(const char *val, const struct kernel_param *kp) |
| 390 | { |
| 391 | /* Match bool exactly, by re-using it. */ |
| 392 | struct kernel_param boolkp = *kp; |
| 393 | bool v; |
| 394 | int ret; |
| 395 | |
| 396 | boolkp.arg = &v; |
| 397 | |
| 398 | ret = param_set_bool(val, &boolkp); |
| 399 | if (ret == 0) |
| 400 | *(int *)kp->arg = v; |
| 401 | return ret; |
| 402 | } |
| 403 | EXPORT_SYMBOL(param_set_bint); |
| 404 | |
| 405 | const struct kernel_param_ops param_ops_bint = { |
| 406 | .flags = KERNEL_PARAM_OPS_FL_NOARG, |
| 407 | .set = param_set_bint, |
| 408 | .get = param_get_int, |
| 409 | }; |
| 410 | EXPORT_SYMBOL(param_ops_bint); |
| 411 | |
| 412 | /* We break the rule and mangle the string. */ |
| 413 | static int param_array(struct module *mod, |
| 414 | const char *name, |
| 415 | const char *val, |
| 416 | unsigned int min, unsigned int max, |
| 417 | void *elem, int elemsize, |
| 418 | int (*set)(const char *, const struct kernel_param *kp), |
| 419 | s16 level, |
| 420 | unsigned int *num) |
| 421 | { |
| 422 | int ret; |
| 423 | struct kernel_param kp; |
| 424 | char save; |
| 425 | |
| 426 | /* Get the name right for errors. */ |
| 427 | kp.name = name; |
| 428 | kp.arg = elem; |
| 429 | kp.level = level; |
| 430 | |
| 431 | *num = 0; |
| 432 | /* We expect a comma-separated list of values. */ |
| 433 | do { |
| 434 | int len; |
| 435 | |
| 436 | if (*num == max) { |
| 437 | pr_err("%s: can only take %i arguments\n", name, max); |
| 438 | return -EINVAL; |
| 439 | } |
| 440 | len = strcspn(val, ","); |
| 441 | |
| 442 | /* nul-terminate and parse */ |
| 443 | save = val[len]; |
| 444 | ((char *)val)[len] = '\0'; |
| 445 | check_kparam_locked(mod); |
| 446 | ret = set(val, &kp); |
| 447 | |
| 448 | if (ret != 0) |
| 449 | return ret; |
| 450 | kp.arg += elemsize; |
| 451 | val += len+1; |
| 452 | (*num)++; |
| 453 | } while (save == ','); |
| 454 | |
| 455 | if (*num < min) { |
| 456 | pr_err("%s: needs at least %i arguments\n", name, min); |
| 457 | return -EINVAL; |
| 458 | } |
| 459 | return 0; |
| 460 | } |
| 461 | |
| 462 | static int param_array_set(const char *val, const struct kernel_param *kp) |
| 463 | { |
| 464 | const struct kparam_array *arr = kp->arr; |
| 465 | unsigned int temp_num; |
| 466 | |
| 467 | return param_array(kp->mod, kp->name, val, 1, arr->max, arr->elem, |
| 468 | arr->elemsize, arr->ops->set, kp->level, |
| 469 | arr->num ?: &temp_num); |
| 470 | } |
| 471 | |
| 472 | static int param_array_get(char *buffer, const struct kernel_param *kp) |
| 473 | { |
| 474 | int i, off, ret; |
| 475 | const struct kparam_array *arr = kp->arr; |
| 476 | struct kernel_param p = *kp; |
| 477 | |
| 478 | for (i = off = 0; i < (arr->num ? *arr->num : arr->max); i++) { |
| 479 | /* Replace \n with comma */ |
| 480 | if (i) |
| 481 | buffer[off - 1] = ','; |
| 482 | p.arg = arr->elem + arr->elemsize * i; |
| 483 | check_kparam_locked(p.mod); |
| 484 | ret = arr->ops->get(buffer + off, &p); |
| 485 | if (ret < 0) |
| 486 | return ret; |
| 487 | off += ret; |
| 488 | } |
| 489 | buffer[off] = '\0'; |
| 490 | return off; |
| 491 | } |
| 492 | |
| 493 | static void param_array_free(void *arg) |
| 494 | { |
| 495 | unsigned int i; |
| 496 | const struct kparam_array *arr = arg; |
| 497 | |
| 498 | if (arr->ops->free) |
| 499 | for (i = 0; i < (arr->num ? *arr->num : arr->max); i++) |
| 500 | arr->ops->free(arr->elem + arr->elemsize * i); |
| 501 | } |
| 502 | |
| 503 | const struct kernel_param_ops param_array_ops = { |
| 504 | .set = param_array_set, |
| 505 | .get = param_array_get, |
| 506 | .free = param_array_free, |
| 507 | }; |
| 508 | EXPORT_SYMBOL(param_array_ops); |
| 509 | |
| 510 | int param_set_copystring(const char *val, const struct kernel_param *kp) |
| 511 | { |
| 512 | const struct kparam_string *kps = kp->str; |
| 513 | |
| 514 | if (strlen(val)+1 > kps->maxlen) { |
| 515 | pr_err("%s: string doesn't fit in %u chars.\n", |
| 516 | kp->name, kps->maxlen-1); |
| 517 | return -ENOSPC; |
| 518 | } |
| 519 | strcpy(kps->string, val); |
| 520 | return 0; |
| 521 | } |
| 522 | EXPORT_SYMBOL(param_set_copystring); |
| 523 | |
| 524 | int param_get_string(char *buffer, const struct kernel_param *kp) |
| 525 | { |
| 526 | const struct kparam_string *kps = kp->str; |
| 527 | return scnprintf(buffer, PAGE_SIZE, "%s\n", kps->string); |
| 528 | } |
| 529 | EXPORT_SYMBOL(param_get_string); |
| 530 | |
| 531 | const struct kernel_param_ops param_ops_string = { |
| 532 | .set = param_set_copystring, |
| 533 | .get = param_get_string, |
| 534 | }; |
| 535 | EXPORT_SYMBOL(param_ops_string); |
| 536 | |
| 537 | /* sysfs output in /sys/modules/XYZ/parameters/ */ |
| 538 | #define to_module_attr(n) container_of(n, struct module_attribute, attr) |
| 539 | #define to_module_kobject(n) container_of(n, struct module_kobject, kobj) |
| 540 | |
| 541 | struct param_attribute |
| 542 | { |
| 543 | struct module_attribute mattr; |
| 544 | const struct kernel_param *param; |
| 545 | }; |
| 546 | |
| 547 | struct module_param_attrs |
| 548 | { |
| 549 | unsigned int num; |
| 550 | struct attribute_group grp; |
| 551 | struct param_attribute attrs[]; |
| 552 | }; |
| 553 | |
| 554 | #ifdef CONFIG_SYSFS |
| 555 | #define to_param_attr(n) container_of(n, struct param_attribute, mattr) |
| 556 | |
| 557 | static ssize_t param_attr_show(struct module_attribute *mattr, |
| 558 | struct module_kobject *mk, char *buf) |
| 559 | { |
| 560 | int count; |
| 561 | struct param_attribute *attribute = to_param_attr(mattr); |
| 562 | |
| 563 | if (!attribute->param->ops->get) |
| 564 | return -EPERM; |
| 565 | |
| 566 | kernel_param_lock(mk->mod); |
| 567 | count = attribute->param->ops->get(buf, attribute->param); |
| 568 | kernel_param_unlock(mk->mod); |
| 569 | return count; |
| 570 | } |
| 571 | |
| 572 | /* sysfs always hands a nul-terminated string in buf. We rely on that. */ |
| 573 | static ssize_t param_attr_store(struct module_attribute *mattr, |
| 574 | struct module_kobject *mk, |
| 575 | const char *buf, size_t len) |
| 576 | { |
| 577 | int err; |
| 578 | struct param_attribute *attribute = to_param_attr(mattr); |
| 579 | |
| 580 | if (!attribute->param->ops->set) |
| 581 | return -EPERM; |
| 582 | |
| 583 | kernel_param_lock(mk->mod); |
| 584 | if (param_check_unsafe(attribute->param)) |
| 585 | err = attribute->param->ops->set(buf, attribute->param); |
| 586 | else |
| 587 | err = -EPERM; |
| 588 | kernel_param_unlock(mk->mod); |
| 589 | if (!err) |
| 590 | return len; |
| 591 | return err; |
| 592 | } |
| 593 | #endif |
| 594 | |
| 595 | #ifdef CONFIG_MODULES |
| 596 | #define __modinit |
| 597 | #else |
| 598 | #define __modinit __init |
| 599 | #endif |
| 600 | |
| 601 | #ifdef CONFIG_SYSFS |
| 602 | void kernel_param_lock(struct module *mod) |
| 603 | { |
| 604 | mutex_lock(KPARAM_MUTEX(mod)); |
| 605 | } |
| 606 | |
| 607 | void kernel_param_unlock(struct module *mod) |
| 608 | { |
| 609 | mutex_unlock(KPARAM_MUTEX(mod)); |
| 610 | } |
| 611 | |
| 612 | EXPORT_SYMBOL(kernel_param_lock); |
| 613 | EXPORT_SYMBOL(kernel_param_unlock); |
| 614 | |
| 615 | /* |
| 616 | * add_sysfs_param - add a parameter to sysfs |
| 617 | * @mk: struct module_kobject |
| 618 | * @kp: the actual parameter definition to add to sysfs |
| 619 | * @name: name of parameter |
| 620 | * |
| 621 | * Create a kobject if for a (per-module) parameter if mp NULL, and |
| 622 | * create file in sysfs. Returns an error on out of memory. Always cleans up |
| 623 | * if there's an error. |
| 624 | */ |
| 625 | static __modinit int add_sysfs_param(struct module_kobject *mk, |
| 626 | const struct kernel_param *kp, |
| 627 | const char *name) |
| 628 | { |
| 629 | struct module_param_attrs *new_mp; |
| 630 | struct attribute **new_attrs; |
| 631 | unsigned int i; |
| 632 | |
| 633 | /* We don't bother calling this with invisible parameters. */ |
| 634 | BUG_ON(!kp->perm); |
| 635 | |
| 636 | if (!mk->mp) { |
| 637 | /* First allocation. */ |
| 638 | mk->mp = kzalloc(sizeof(*mk->mp), GFP_KERNEL); |
| 639 | if (!mk->mp) |
| 640 | return -ENOMEM; |
| 641 | mk->mp->grp.name = "parameters"; |
| 642 | /* NULL-terminated attribute array. */ |
| 643 | mk->mp->grp.attrs = kzalloc(sizeof(mk->mp->grp.attrs[0]), |
| 644 | GFP_KERNEL); |
| 645 | /* Caller will cleanup via free_module_param_attrs */ |
| 646 | if (!mk->mp->grp.attrs) |
| 647 | return -ENOMEM; |
| 648 | } |
| 649 | |
| 650 | /* Enlarge allocations. */ |
| 651 | new_mp = krealloc(mk->mp, |
| 652 | sizeof(*mk->mp) + |
| 653 | sizeof(mk->mp->attrs[0]) * (mk->mp->num + 1), |
| 654 | GFP_KERNEL); |
| 655 | if (!new_mp) |
| 656 | return -ENOMEM; |
| 657 | mk->mp = new_mp; |
| 658 | |
| 659 | /* Extra pointer for NULL terminator */ |
| 660 | new_attrs = krealloc(mk->mp->grp.attrs, |
| 661 | sizeof(mk->mp->grp.attrs[0]) * (mk->mp->num + 2), |
| 662 | GFP_KERNEL); |
| 663 | if (!new_attrs) |
| 664 | return -ENOMEM; |
| 665 | mk->mp->grp.attrs = new_attrs; |
| 666 | |
| 667 | /* Tack new one on the end. */ |
| 668 | memset(&mk->mp->attrs[mk->mp->num], 0, sizeof(mk->mp->attrs[0])); |
| 669 | sysfs_attr_init(&mk->mp->attrs[mk->mp->num].mattr.attr); |
| 670 | mk->mp->attrs[mk->mp->num].param = kp; |
| 671 | mk->mp->attrs[mk->mp->num].mattr.show = param_attr_show; |
| 672 | /* Do not allow runtime DAC changes to make param writable. */ |
| 673 | if ((kp->perm & (S_IWUSR | S_IWGRP | S_IWOTH)) != 0) |
| 674 | mk->mp->attrs[mk->mp->num].mattr.store = param_attr_store; |
| 675 | else |
| 676 | mk->mp->attrs[mk->mp->num].mattr.store = NULL; |
| 677 | mk->mp->attrs[mk->mp->num].mattr.attr.name = (char *)name; |
| 678 | mk->mp->attrs[mk->mp->num].mattr.attr.mode = kp->perm; |
| 679 | mk->mp->num++; |
| 680 | |
| 681 | /* Fix up all the pointers, since krealloc can move us */ |
| 682 | for (i = 0; i < mk->mp->num; i++) |
| 683 | mk->mp->grp.attrs[i] = &mk->mp->attrs[i].mattr.attr; |
| 684 | mk->mp->grp.attrs[mk->mp->num] = NULL; |
| 685 | return 0; |
| 686 | } |
| 687 | |
| 688 | #ifdef CONFIG_MODULES |
| 689 | static void free_module_param_attrs(struct module_kobject *mk) |
| 690 | { |
| 691 | if (mk->mp) |
| 692 | kfree(mk->mp->grp.attrs); |
| 693 | kfree(mk->mp); |
| 694 | mk->mp = NULL; |
| 695 | } |
| 696 | |
| 697 | /* |
| 698 | * module_param_sysfs_setup - setup sysfs support for one module |
| 699 | * @mod: module |
| 700 | * @kparam: module parameters (array) |
| 701 | * @num_params: number of module parameters |
| 702 | * |
| 703 | * Adds sysfs entries for module parameters under |
| 704 | * /sys/module/[mod->name]/parameters/ |
| 705 | */ |
| 706 | int module_param_sysfs_setup(struct module *mod, |
| 707 | const struct kernel_param *kparam, |
| 708 | unsigned int num_params) |
| 709 | { |
| 710 | int i, err; |
| 711 | bool params = false; |
| 712 | |
| 713 | for (i = 0; i < num_params; i++) { |
| 714 | if (kparam[i].perm == 0) |
| 715 | continue; |
| 716 | err = add_sysfs_param(&mod->mkobj, &kparam[i], kparam[i].name); |
| 717 | if (err) { |
| 718 | free_module_param_attrs(&mod->mkobj); |
| 719 | return err; |
| 720 | } |
| 721 | params = true; |
| 722 | } |
| 723 | |
| 724 | if (!params) |
| 725 | return 0; |
| 726 | |
| 727 | /* Create the param group. */ |
| 728 | err = sysfs_create_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp); |
| 729 | if (err) |
| 730 | free_module_param_attrs(&mod->mkobj); |
| 731 | return err; |
| 732 | } |
| 733 | |
| 734 | /* |
| 735 | * module_param_sysfs_remove - remove sysfs support for one module |
| 736 | * @mod: module |
| 737 | * |
| 738 | * Remove sysfs entries for module parameters and the corresponding |
| 739 | * kobject. |
| 740 | */ |
| 741 | void module_param_sysfs_remove(struct module *mod) |
| 742 | { |
| 743 | if (mod->mkobj.mp) { |
| 744 | sysfs_remove_group(&mod->mkobj.kobj, &mod->mkobj.mp->grp); |
| 745 | /* We are positive that no one is using any param |
| 746 | * attrs at this point. Deallocate immediately. */ |
| 747 | free_module_param_attrs(&mod->mkobj); |
| 748 | } |
| 749 | } |
| 750 | #endif |
| 751 | |
| 752 | void destroy_params(const struct kernel_param *params, unsigned num) |
| 753 | { |
| 754 | unsigned int i; |
| 755 | |
| 756 | for (i = 0; i < num; i++) |
| 757 | if (params[i].ops->free) |
| 758 | params[i].ops->free(params[i].arg); |
| 759 | } |
| 760 | |
| 761 | static struct module_kobject * __init locate_module_kobject(const char *name) |
| 762 | { |
| 763 | struct module_kobject *mk; |
| 764 | struct kobject *kobj; |
| 765 | int err; |
| 766 | |
| 767 | kobj = kset_find_obj(module_kset, name); |
| 768 | if (kobj) { |
| 769 | mk = to_module_kobject(kobj); |
| 770 | } else { |
| 771 | mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL); |
| 772 | BUG_ON(!mk); |
| 773 | |
| 774 | mk->mod = THIS_MODULE; |
| 775 | mk->kobj.kset = module_kset; |
| 776 | err = kobject_init_and_add(&mk->kobj, &module_ktype, NULL, |
| 777 | "%s", name); |
| 778 | #ifdef CONFIG_MODULES |
| 779 | if (!err) |
| 780 | err = sysfs_create_file(&mk->kobj, &module_uevent.attr); |
| 781 | #endif |
| 782 | if (err) { |
| 783 | kobject_put(&mk->kobj); |
| 784 | pr_crit("Adding module '%s' to sysfs failed (%d), the system may be unstable.\n", |
| 785 | name, err); |
| 786 | return NULL; |
| 787 | } |
| 788 | |
| 789 | /* So that we hold reference in both cases. */ |
| 790 | kobject_get(&mk->kobj); |
| 791 | } |
| 792 | |
| 793 | return mk; |
| 794 | } |
| 795 | |
| 796 | static void __init kernel_add_sysfs_param(const char *name, |
| 797 | const struct kernel_param *kparam, |
| 798 | unsigned int name_skip) |
| 799 | { |
| 800 | struct module_kobject *mk; |
| 801 | int err; |
| 802 | |
| 803 | mk = locate_module_kobject(name); |
| 804 | if (!mk) |
| 805 | return; |
| 806 | |
| 807 | /* We need to remove old parameters before adding more. */ |
| 808 | if (mk->mp) |
| 809 | sysfs_remove_group(&mk->kobj, &mk->mp->grp); |
| 810 | |
| 811 | /* These should not fail at boot. */ |
| 812 | err = add_sysfs_param(mk, kparam, kparam->name + name_skip); |
| 813 | BUG_ON(err); |
| 814 | err = sysfs_create_group(&mk->kobj, &mk->mp->grp); |
| 815 | BUG_ON(err); |
| 816 | kobject_uevent(&mk->kobj, KOBJ_ADD); |
| 817 | kobject_put(&mk->kobj); |
| 818 | } |
| 819 | |
| 820 | /* |
| 821 | * param_sysfs_builtin - add sysfs parameters for built-in modules |
| 822 | * |
| 823 | * Add module_parameters to sysfs for "modules" built into the kernel. |
| 824 | * |
| 825 | * The "module" name (KBUILD_MODNAME) is stored before a dot, the |
| 826 | * "parameter" name is stored behind a dot in kernel_param->name. So, |
| 827 | * extract the "module" name for all built-in kernel_param-eters, |
| 828 | * and for all who have the same, call kernel_add_sysfs_param. |
| 829 | */ |
| 830 | static void __init param_sysfs_builtin(void) |
| 831 | { |
| 832 | const struct kernel_param *kp; |
| 833 | unsigned int name_len; |
| 834 | char modname[MODULE_NAME_LEN]; |
| 835 | |
| 836 | for (kp = __start___param; kp < __stop___param; kp++) { |
| 837 | char *dot; |
| 838 | |
| 839 | if (kp->perm == 0) |
| 840 | continue; |
| 841 | |
| 842 | dot = strchr(kp->name, '.'); |
| 843 | if (!dot) { |
| 844 | /* This happens for core_param() */ |
| 845 | strcpy(modname, "kernel"); |
| 846 | name_len = 0; |
| 847 | } else { |
| 848 | name_len = dot - kp->name + 1; |
| 849 | strlcpy(modname, kp->name, name_len); |
| 850 | } |
| 851 | kernel_add_sysfs_param(modname, kp, name_len); |
| 852 | } |
| 853 | } |
| 854 | |
| 855 | ssize_t __modver_version_show(struct module_attribute *mattr, |
| 856 | struct module_kobject *mk, char *buf) |
| 857 | { |
| 858 | struct module_version_attribute *vattr = |
| 859 | container_of(mattr, struct module_version_attribute, mattr); |
| 860 | |
| 861 | return scnprintf(buf, PAGE_SIZE, "%s\n", vattr->version); |
| 862 | } |
| 863 | |
| 864 | extern const struct module_version_attribute __start___modver[]; |
| 865 | extern const struct module_version_attribute __stop___modver[]; |
| 866 | |
| 867 | static void __init version_sysfs_builtin(void) |
| 868 | { |
| 869 | const struct module_version_attribute *vattr; |
| 870 | struct module_kobject *mk; |
| 871 | int err; |
| 872 | |
| 873 | for (vattr = __start___modver; vattr < __stop___modver; vattr++) { |
| 874 | mk = locate_module_kobject(vattr->module_name); |
| 875 | if (mk) { |
| 876 | err = sysfs_create_file(&mk->kobj, &vattr->mattr.attr); |
| 877 | WARN_ON_ONCE(err); |
| 878 | kobject_uevent(&mk->kobj, KOBJ_ADD); |
| 879 | kobject_put(&mk->kobj); |
| 880 | } |
| 881 | } |
| 882 | } |
| 883 | |
| 884 | /* module-related sysfs stuff */ |
| 885 | |
| 886 | static ssize_t module_attr_show(struct kobject *kobj, |
| 887 | struct attribute *attr, |
| 888 | char *buf) |
| 889 | { |
| 890 | struct module_attribute *attribute; |
| 891 | struct module_kobject *mk; |
| 892 | int ret; |
| 893 | |
| 894 | attribute = to_module_attr(attr); |
| 895 | mk = to_module_kobject(kobj); |
| 896 | |
| 897 | if (!attribute->show) |
| 898 | return -EIO; |
| 899 | |
| 900 | ret = attribute->show(attribute, mk, buf); |
| 901 | |
| 902 | return ret; |
| 903 | } |
| 904 | |
| 905 | static ssize_t module_attr_store(struct kobject *kobj, |
| 906 | struct attribute *attr, |
| 907 | const char *buf, size_t len) |
| 908 | { |
| 909 | struct module_attribute *attribute; |
| 910 | struct module_kobject *mk; |
| 911 | int ret; |
| 912 | |
| 913 | attribute = to_module_attr(attr); |
| 914 | mk = to_module_kobject(kobj); |
| 915 | |
| 916 | if (!attribute->store) |
| 917 | return -EIO; |
| 918 | |
| 919 | ret = attribute->store(attribute, mk, buf, len); |
| 920 | |
| 921 | return ret; |
| 922 | } |
| 923 | |
| 924 | static const struct sysfs_ops module_sysfs_ops = { |
| 925 | .show = module_attr_show, |
| 926 | .store = module_attr_store, |
| 927 | }; |
| 928 | |
| 929 | static int uevent_filter(struct kset *kset, struct kobject *kobj) |
| 930 | { |
| 931 | struct kobj_type *ktype = get_ktype(kobj); |
| 932 | |
| 933 | if (ktype == &module_ktype) |
| 934 | return 1; |
| 935 | return 0; |
| 936 | } |
| 937 | |
| 938 | static const struct kset_uevent_ops module_uevent_ops = { |
| 939 | .filter = uevent_filter, |
| 940 | }; |
| 941 | |
| 942 | struct kset *module_kset; |
| 943 | int module_sysfs_initialized; |
| 944 | |
| 945 | static void module_kobj_release(struct kobject *kobj) |
| 946 | { |
| 947 | struct module_kobject *mk = to_module_kobject(kobj); |
| 948 | complete(mk->kobj_completion); |
| 949 | } |
| 950 | |
| 951 | struct kobj_type module_ktype = { |
| 952 | .release = module_kobj_release, |
| 953 | .sysfs_ops = &module_sysfs_ops, |
| 954 | }; |
| 955 | |
| 956 | /* |
| 957 | * param_sysfs_init - wrapper for built-in params support |
| 958 | */ |
| 959 | static int __init param_sysfs_init(void) |
| 960 | { |
| 961 | module_kset = kset_create_and_add("module", &module_uevent_ops, NULL); |
| 962 | if (!module_kset) { |
| 963 | printk(KERN_WARNING "%s (%d): error creating kset\n", |
| 964 | __FILE__, __LINE__); |
| 965 | return -ENOMEM; |
| 966 | } |
| 967 | module_sysfs_initialized = 1; |
| 968 | |
| 969 | version_sysfs_builtin(); |
| 970 | param_sysfs_builtin(); |
| 971 | |
| 972 | return 0; |
| 973 | } |
| 974 | subsys_initcall(param_sysfs_init); |
| 975 | |
| 976 | #endif /* CONFIG_SYSFS */ |