1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1997 Doug Rabson 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/kernel.h> 34 #include <sys/systm.h> 35 #include <sys/eventhandler.h> 36 #include <sys/malloc.h> 37 #include <sys/sysproto.h> 38 #include <sys/sysent.h> 39 #include <sys/proc.h> 40 #include <sys/lock.h> 41 #include <sys/mutex.h> 42 #include <sys/reboot.h> 43 #include <sys/sx.h> 44 #include <sys/module.h> 45 #include <sys/linker.h> 46 47 static MALLOC_DEFINE(M_MODULE, "module", "module data structures"); 48 49 struct module { 50 TAILQ_ENTRY(module) link; /* chain together all modules */ 51 TAILQ_ENTRY(module) flink; /* all modules in a file */ 52 struct linker_file *file; /* file which contains this module */ 53 int refs; /* reference count */ 54 int id; /* unique id number */ 55 char *name; /* module name */ 56 modeventhand_t handler; /* event handler */ 57 void *arg; /* argument for handler */ 58 modspecific_t data; /* module specific data */ 59 }; 60 61 #define MOD_EVENT(mod, type) (mod)->handler((mod), (type), (mod)->arg) 62 63 static TAILQ_HEAD(modulelist, module) modules; 64 struct sx modules_sx; 65 static int nextid = 1; 66 static void module_shutdown(void *, int); 67 68 static int 69 modevent_nop(module_t mod, int what, void *arg) 70 { 71 72 switch(what) { 73 case MOD_LOAD: 74 return (0); 75 case MOD_UNLOAD: 76 return (EBUSY); 77 default: 78 return (EOPNOTSUPP); 79 } 80 } 81 82 static void 83 module_init(void *arg) 84 { 85 86 sx_init(&modules_sx, "module subsystem sx lock"); 87 TAILQ_INIT(&modules); 88 EVENTHANDLER_REGISTER(shutdown_final, module_shutdown, NULL, 89 SHUTDOWN_PRI_DEFAULT); 90 } 91 92 SYSINIT(module, SI_SUB_KLD, SI_ORDER_FIRST, module_init, NULL); 93 94 static void 95 module_shutdown(void *arg1, int arg2) 96 { 97 module_t mod; 98 99 if (arg2 & RB_NOSYNC) 100 return; 101 mtx_lock(&Giant); 102 MOD_SLOCK; 103 TAILQ_FOREACH_REVERSE(mod, &modules, modulelist, link) 104 MOD_EVENT(mod, MOD_SHUTDOWN); 105 MOD_SUNLOCK; 106 mtx_unlock(&Giant); 107 } 108 109 void 110 module_register_init(const void *arg) 111 { 112 const moduledata_t *data = (const moduledata_t *)arg; 113 int error; 114 module_t mod; 115 116 mtx_lock(&Giant); 117 MOD_SLOCK; 118 mod = module_lookupbyname(data->name); 119 if (mod == NULL) 120 panic("module_register_init: module named %s not found\n", 121 data->name); 122 MOD_SUNLOCK; 123 error = MOD_EVENT(mod, MOD_LOAD); 124 if (error) { 125 MOD_EVENT(mod, MOD_UNLOAD); 126 MOD_XLOCK; 127 module_release(mod); 128 MOD_XUNLOCK; 129 printf("module_register_init: MOD_LOAD (%s, %p, %p) error" 130 " %d\n", data->name, (void *)data->evhand, data->priv, 131 error); 132 } else { 133 MOD_XLOCK; 134 if (mod->file) { 135 /* 136 * Once a module is successfully loaded, move 137 * it to the head of the module list for this 138 * linker file. This resorts the list so that 139 * when the kernel linker iterates over the 140 * modules to unload them, it will unload them 141 * in the reverse order they were loaded. 142 */ 143 TAILQ_REMOVE(&mod->file->modules, mod, flink); 144 TAILQ_INSERT_HEAD(&mod->file->modules, mod, flink); 145 } 146 MOD_XUNLOCK; 147 } 148 mtx_unlock(&Giant); 149 } 150 151 int 152 module_register(const moduledata_t *data, linker_file_t container) 153 { 154 size_t namelen; 155 module_t newmod; 156 157 MOD_XLOCK; 158 newmod = module_lookupbyname(data->name); 159 if (newmod != NULL) { 160 MOD_XUNLOCK; 161 printf("%s: cannot register %s from %s; already loaded from %s\n", 162 __func__, data->name, container->filename, newmod->file->filename); 163 return (EEXIST); 164 } 165 namelen = strlen(data->name) + 1; 166 newmod = malloc(sizeof(struct module) + namelen, M_MODULE, M_WAITOK); 167 newmod->refs = 1; 168 newmod->id = nextid++; 169 newmod->name = (char *)(newmod + 1); 170 strcpy(newmod->name, data->name); 171 newmod->handler = data->evhand ? data->evhand : modevent_nop; 172 newmod->arg = data->priv; 173 bzero(&newmod->data, sizeof(newmod->data)); 174 TAILQ_INSERT_TAIL(&modules, newmod, link); 175 176 if (container) 177 TAILQ_INSERT_TAIL(&container->modules, newmod, flink); 178 newmod->file = container; 179 MOD_XUNLOCK; 180 return (0); 181 } 182 183 void 184 module_reference(module_t mod) 185 { 186 187 MOD_XLOCK_ASSERT; 188 189 MOD_DPF(REFS, ("module_reference: before, refs=%d\n", mod->refs)); 190 mod->refs++; 191 } 192 193 void 194 module_release(module_t mod) 195 { 196 197 MOD_XLOCK_ASSERT; 198 199 if (mod->refs <= 0) 200 panic("module_release: bad reference count"); 201 202 MOD_DPF(REFS, ("module_release: before, refs=%d\n", mod->refs)); 203 204 mod->refs--; 205 if (mod->refs == 0) { 206 TAILQ_REMOVE(&modules, mod, link); 207 if (mod->file) 208 TAILQ_REMOVE(&mod->file->modules, mod, flink); 209 free(mod, M_MODULE); 210 } 211 } 212 213 module_t 214 module_lookupbyname(const char *name) 215 { 216 module_t mod; 217 int err; 218 219 MOD_LOCK_ASSERT; 220 221 TAILQ_FOREACH(mod, &modules, link) { 222 err = strcmp(mod->name, name); 223 if (err == 0) 224 return (mod); 225 } 226 return (NULL); 227 } 228 229 module_t 230 module_lookupbyid(int modid) 231 { 232 module_t mod; 233 234 MOD_LOCK_ASSERT; 235 236 TAILQ_FOREACH(mod, &modules, link) 237 if (mod->id == modid) 238 return(mod); 239 return (NULL); 240 } 241 242 int 243 module_quiesce(module_t mod) 244 { 245 int error; 246 247 mtx_lock(&Giant); 248 error = MOD_EVENT(mod, MOD_QUIESCE); 249 mtx_unlock(&Giant); 250 if (error == EOPNOTSUPP || error == EINVAL) 251 error = 0; 252 return (error); 253 } 254 255 int 256 module_unload(module_t mod) 257 { 258 int error; 259 260 mtx_lock(&Giant); 261 error = MOD_EVENT(mod, MOD_UNLOAD); 262 mtx_unlock(&Giant); 263 return (error); 264 } 265 266 int 267 module_getid(module_t mod) 268 { 269 270 MOD_LOCK_ASSERT; 271 return (mod->id); 272 } 273 274 module_t 275 module_getfnext(module_t mod) 276 { 277 278 MOD_LOCK_ASSERT; 279 return (TAILQ_NEXT(mod, flink)); 280 } 281 282 const char * 283 module_getname(module_t mod) 284 { 285 286 MOD_LOCK_ASSERT; 287 return (mod->name); 288 } 289 290 void 291 module_setspecific(module_t mod, modspecific_t *datap) 292 { 293 294 MOD_XLOCK_ASSERT; 295 mod->data = *datap; 296 } 297 298 linker_file_t 299 module_file(module_t mod) 300 { 301 302 return (mod->file); 303 } 304 305 /* 306 * Syscalls. 307 */ 308 int 309 sys_modnext(struct thread *td, struct modnext_args *uap) 310 { 311 module_t mod; 312 int error = 0; 313 314 td->td_retval[0] = -1; 315 316 MOD_SLOCK; 317 if (uap->modid == 0) { 318 mod = TAILQ_FIRST(&modules); 319 if (mod) 320 td->td_retval[0] = mod->id; 321 else 322 error = ENOENT; 323 goto done2; 324 } 325 mod = module_lookupbyid(uap->modid); 326 if (mod == NULL) { 327 error = ENOENT; 328 goto done2; 329 } 330 if (TAILQ_NEXT(mod, link)) 331 td->td_retval[0] = TAILQ_NEXT(mod, link)->id; 332 else 333 td->td_retval[0] = 0; 334 done2: 335 MOD_SUNLOCK; 336 return (error); 337 } 338 339 int 340 sys_modfnext(struct thread *td, struct modfnext_args *uap) 341 { 342 module_t mod; 343 int error; 344 345 td->td_retval[0] = -1; 346 347 MOD_SLOCK; 348 mod = module_lookupbyid(uap->modid); 349 if (mod == NULL) { 350 error = ENOENT; 351 } else { 352 error = 0; 353 if (TAILQ_NEXT(mod, flink)) 354 td->td_retval[0] = TAILQ_NEXT(mod, flink)->id; 355 else 356 td->td_retval[0] = 0; 357 } 358 MOD_SUNLOCK; 359 return (error); 360 } 361 362 struct module_stat_v1 { 363 int version; /* set to sizeof(struct module_stat) */ 364 char name[MAXMODNAME]; 365 int refs; 366 int id; 367 }; 368 369 int 370 sys_modstat(struct thread *td, struct modstat_args *uap) 371 { 372 module_t mod; 373 modspecific_t data; 374 int error = 0; 375 int id, namelen, refs, version; 376 struct module_stat *stat; 377 char *name; 378 379 MOD_SLOCK; 380 mod = module_lookupbyid(uap->modid); 381 if (mod == NULL) { 382 MOD_SUNLOCK; 383 return (ENOENT); 384 } 385 id = mod->id; 386 refs = mod->refs; 387 name = mod->name; 388 data = mod->data; 389 MOD_SUNLOCK; 390 stat = uap->stat; 391 392 /* 393 * Check the version of the user's structure. 394 */ 395 if ((error = copyin(&stat->version, &version, sizeof(version))) != 0) 396 return (error); 397 if (version != sizeof(struct module_stat_v1) 398 && version != sizeof(struct module_stat)) 399 return (EINVAL); 400 namelen = strlen(mod->name) + 1; 401 if (namelen > MAXMODNAME) 402 namelen = MAXMODNAME; 403 if ((error = copyout(name, &stat->name[0], namelen)) != 0) 404 return (error); 405 406 if ((error = copyout(&refs, &stat->refs, sizeof(int))) != 0) 407 return (error); 408 if ((error = copyout(&id, &stat->id, sizeof(int))) != 0) 409 return (error); 410 411 /* 412 * >v1 stat includes module data. 413 */ 414 if (version == sizeof(struct module_stat)) 415 if ((error = copyout(&data, &stat->data, 416 sizeof(data))) != 0) 417 return (error); 418 td->td_retval[0] = 0; 419 return (error); 420 } 421 422 int 423 sys_modfind(struct thread *td, struct modfind_args *uap) 424 { 425 int error = 0; 426 char name[MAXMODNAME]; 427 module_t mod; 428 429 if ((error = copyinstr(uap->name, name, sizeof name, 0)) != 0) 430 return (error); 431 432 MOD_SLOCK; 433 mod = module_lookupbyname(name); 434 if (mod == NULL) 435 error = ENOENT; 436 else 437 td->td_retval[0] = module_getid(mod); 438 MOD_SUNLOCK; 439 return (error); 440 } 441 442 MODULE_VERSION(kernel, __FreeBSD_version); 443 444 #ifdef COMPAT_FREEBSD32 445 #include <sys/mount.h> 446 #include <sys/socket.h> 447 #include <compat/freebsd32/freebsd32_util.h> 448 #include <compat/freebsd32/freebsd32.h> 449 #include <compat/freebsd32/freebsd32_proto.h> 450 451 typedef union modspecific32 { 452 int intval; 453 uint32_t uintval; 454 int longval; 455 uint32_t ulongval; 456 } modspecific32_t; 457 458 struct module_stat32 { 459 int version; 460 char name[MAXMODNAME]; 461 int refs; 462 int id; 463 modspecific32_t data; 464 }; 465 466 int 467 freebsd32_modstat(struct thread *td, struct freebsd32_modstat_args *uap) 468 { 469 module_t mod; 470 modspecific32_t data32; 471 int error = 0; 472 int id, namelen, refs, version; 473 struct module_stat32 *stat32; 474 char *name; 475 476 MOD_SLOCK; 477 mod = module_lookupbyid(uap->modid); 478 if (mod == NULL) { 479 MOD_SUNLOCK; 480 return (ENOENT); 481 } 482 483 id = mod->id; 484 refs = mod->refs; 485 name = mod->name; 486 CP(mod->data, data32, intval); 487 CP(mod->data, data32, uintval); 488 CP(mod->data, data32, longval); 489 CP(mod->data, data32, ulongval); 490 MOD_SUNLOCK; 491 stat32 = uap->stat; 492 493 if ((error = copyin(&stat32->version, &version, sizeof(version))) != 0) 494 return (error); 495 if (version != sizeof(struct module_stat_v1) 496 && version != sizeof(struct module_stat32)) 497 return (EINVAL); 498 namelen = strlen(mod->name) + 1; 499 if (namelen > MAXMODNAME) 500 namelen = MAXMODNAME; 501 if ((error = copyout(name, &stat32->name[0], namelen)) != 0) 502 return (error); 503 504 if ((error = copyout(&refs, &stat32->refs, sizeof(int))) != 0) 505 return (error); 506 if ((error = copyout(&id, &stat32->id, sizeof(int))) != 0) 507 return (error); 508 509 /* 510 * >v1 stat includes module data. 511 */ 512 if (version == sizeof(struct module_stat32)) 513 if ((error = copyout(&data32, &stat32->data, 514 sizeof(data32))) != 0) 515 return (error); 516 td->td_retval[0] = 0; 517 return (error); 518 } 519 #endif 520