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 "opt_compat.h" 30 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 #include <sys/param.h> 35 #include <sys/kernel.h> 36 #include <sys/systm.h> 37 #include <sys/eventhandler.h> 38 #include <sys/malloc.h> 39 #include <sys/sysproto.h> 40 #include <sys/sysent.h> 41 #include <sys/proc.h> 42 #include <sys/lock.h> 43 #include <sys/mutex.h> 44 #include <sys/reboot.h> 45 #include <sys/sx.h> 46 #include <sys/module.h> 47 #include <sys/linker.h> 48 49 static MALLOC_DEFINE(M_MODULE, "module", "module data structures"); 50 51 struct module { 52 TAILQ_ENTRY(module) link; /* chain together all modules */ 53 TAILQ_ENTRY(module) flink; /* all modules in a file */ 54 struct linker_file *file; /* file which contains this module */ 55 int refs; /* reference count */ 56 int id; /* unique id number */ 57 char *name; /* module name */ 58 modeventhand_t handler; /* event handler */ 59 void *arg; /* argument for handler */ 60 modspecific_t data; /* module specific data */ 61 }; 62 63 #define MOD_EVENT(mod, type) (mod)->handler((mod), (type), (mod)->arg) 64 65 static TAILQ_HEAD(modulelist, module) modules; 66 struct sx modules_sx; 67 static int nextid = 1; 68 static void module_shutdown(void *, int); 69 70 static int 71 modevent_nop(module_t mod, int what, void *arg) 72 { 73 74 switch(what) { 75 case MOD_LOAD: 76 return (0); 77 case MOD_UNLOAD: 78 return (EBUSY); 79 default: 80 return (EOPNOTSUPP); 81 } 82 } 83 84 static void 85 module_init(void *arg) 86 { 87 88 sx_init(&modules_sx, "module subsystem sx lock"); 89 TAILQ_INIT(&modules); 90 EVENTHANDLER_REGISTER(shutdown_final, module_shutdown, NULL, 91 SHUTDOWN_PRI_DEFAULT); 92 } 93 94 SYSINIT(module, SI_SUB_KLD, SI_ORDER_FIRST, module_init, 0); 95 96 static void 97 module_shutdown(void *arg1, int arg2) 98 { 99 module_t mod; 100 101 if (arg2 & RB_NOSYNC) 102 return; 103 mtx_lock(&Giant); 104 MOD_SLOCK; 105 TAILQ_FOREACH_REVERSE(mod, &modules, modulelist, link) 106 MOD_EVENT(mod, MOD_SHUTDOWN); 107 MOD_SUNLOCK; 108 mtx_unlock(&Giant); 109 } 110 111 void 112 module_register_init(const void *arg) 113 { 114 const moduledata_t *data = (const moduledata_t *)arg; 115 int error; 116 module_t mod; 117 118 mtx_lock(&Giant); 119 MOD_SLOCK; 120 mod = module_lookupbyname(data->name); 121 if (mod == NULL) 122 panic("module_register_init: module named %s not found\n", 123 data->name); 124 MOD_SUNLOCK; 125 error = MOD_EVENT(mod, MOD_LOAD); 126 if (error) { 127 MOD_EVENT(mod, MOD_UNLOAD); 128 MOD_XLOCK; 129 module_release(mod); 130 MOD_XUNLOCK; 131 printf("module_register_init: MOD_LOAD (%s, %p, %p) error" 132 " %d\n", data->name, (void *)data->evhand, data->priv, 133 error); 134 } else { 135 MOD_XLOCK; 136 if (mod->file) { 137 /* 138 * Once a module is successfully loaded, move 139 * it to the head of the module list for this 140 * linker file. This resorts the list so that 141 * when the kernel linker iterates over the 142 * modules to unload them, it will unload them 143 * in the reverse order they were loaded. 144 */ 145 TAILQ_REMOVE(&mod->file->modules, mod, flink); 146 TAILQ_INSERT_HEAD(&mod->file->modules, mod, flink); 147 } 148 MOD_XUNLOCK; 149 } 150 mtx_unlock(&Giant); 151 } 152 153 int 154 module_register(const moduledata_t *data, linker_file_t container) 155 { 156 size_t namelen; 157 module_t newmod; 158 159 MOD_XLOCK; 160 newmod = module_lookupbyname(data->name); 161 if (newmod != NULL) { 162 MOD_XUNLOCK; 163 printf("%s: cannot register %s from %s; already loaded from %s\n", 164 __func__, data->name, container->filename, newmod->file->filename); 165 return (EEXIST); 166 } 167 namelen = strlen(data->name) + 1; 168 newmod = malloc(sizeof(struct module) + namelen, M_MODULE, M_WAITOK); 169 newmod->refs = 1; 170 newmod->id = nextid++; 171 newmod->name = (char *)(newmod + 1); 172 strcpy(newmod->name, data->name); 173 newmod->handler = data->evhand ? data->evhand : modevent_nop; 174 newmod->arg = data->priv; 175 bzero(&newmod->data, sizeof(newmod->data)); 176 TAILQ_INSERT_TAIL(&modules, newmod, link); 177 178 if (container) 179 TAILQ_INSERT_TAIL(&container->modules, newmod, flink); 180 newmod->file = container; 181 MOD_XUNLOCK; 182 return (0); 183 } 184 185 void 186 module_reference(module_t mod) 187 { 188 189 MOD_XLOCK_ASSERT; 190 191 MOD_DPF(REFS, ("module_reference: before, refs=%d\n", mod->refs)); 192 mod->refs++; 193 } 194 195 void 196 module_release(module_t mod) 197 { 198 199 MOD_XLOCK_ASSERT; 200 201 if (mod->refs <= 0) 202 panic("module_release: bad reference count"); 203 204 MOD_DPF(REFS, ("module_release: before, refs=%d\n", mod->refs)); 205 206 mod->refs--; 207 if (mod->refs == 0) { 208 TAILQ_REMOVE(&modules, mod, link); 209 if (mod->file) 210 TAILQ_REMOVE(&mod->file->modules, mod, flink); 211 free(mod, M_MODULE); 212 } 213 } 214 215 module_t 216 module_lookupbyname(const char *name) 217 { 218 module_t mod; 219 int err; 220 221 MOD_LOCK_ASSERT; 222 223 TAILQ_FOREACH(mod, &modules, link) { 224 err = strcmp(mod->name, name); 225 if (err == 0) 226 return (mod); 227 } 228 return (NULL); 229 } 230 231 module_t 232 module_lookupbyid(int modid) 233 { 234 module_t mod; 235 236 MOD_LOCK_ASSERT; 237 238 TAILQ_FOREACH(mod, &modules, link) 239 if (mod->id == modid) 240 return(mod); 241 return (NULL); 242 } 243 244 int 245 module_quiesce(module_t mod) 246 { 247 int error; 248 249 mtx_lock(&Giant); 250 error = MOD_EVENT(mod, MOD_QUIESCE); 251 mtx_unlock(&Giant); 252 if (error == EOPNOTSUPP || error == EINVAL) 253 error = 0; 254 return (error); 255 } 256 257 int 258 module_unload(module_t mod) 259 { 260 int error; 261 262 mtx_lock(&Giant); 263 error = MOD_EVENT(mod, MOD_UNLOAD); 264 mtx_unlock(&Giant); 265 return (error); 266 } 267 268 int 269 module_getid(module_t mod) 270 { 271 272 MOD_LOCK_ASSERT; 273 return (mod->id); 274 } 275 276 module_t 277 module_getfnext(module_t mod) 278 { 279 280 MOD_LOCK_ASSERT; 281 return (TAILQ_NEXT(mod, flink)); 282 } 283 284 const char * 285 module_getname(module_t mod) 286 { 287 288 MOD_LOCK_ASSERT; 289 return (mod->name); 290 } 291 292 void 293 module_setspecific(module_t mod, modspecific_t *datap) 294 { 295 296 MOD_XLOCK_ASSERT; 297 mod->data = *datap; 298 } 299 300 linker_file_t 301 module_file(module_t mod) 302 { 303 304 return (mod->file); 305 } 306 307 /* 308 * Syscalls. 309 */ 310 int 311 sys_modnext(struct thread *td, struct modnext_args *uap) 312 { 313 module_t mod; 314 int error = 0; 315 316 td->td_retval[0] = -1; 317 318 MOD_SLOCK; 319 if (uap->modid == 0) { 320 mod = TAILQ_FIRST(&modules); 321 if (mod) 322 td->td_retval[0] = mod->id; 323 else 324 error = ENOENT; 325 goto done2; 326 } 327 mod = module_lookupbyid(uap->modid); 328 if (mod == NULL) { 329 error = ENOENT; 330 goto done2; 331 } 332 if (TAILQ_NEXT(mod, link)) 333 td->td_retval[0] = TAILQ_NEXT(mod, link)->id; 334 else 335 td->td_retval[0] = 0; 336 done2: 337 MOD_SUNLOCK; 338 return (error); 339 } 340 341 int 342 sys_modfnext(struct thread *td, struct modfnext_args *uap) 343 { 344 module_t mod; 345 int error; 346 347 td->td_retval[0] = -1; 348 349 MOD_SLOCK; 350 mod = module_lookupbyid(uap->modid); 351 if (mod == NULL) { 352 error = ENOENT; 353 } else { 354 error = 0; 355 if (TAILQ_NEXT(mod, flink)) 356 td->td_retval[0] = TAILQ_NEXT(mod, flink)->id; 357 else 358 td->td_retval[0] = 0; 359 } 360 MOD_SUNLOCK; 361 return (error); 362 } 363 364 struct module_stat_v1 { 365 int version; /* set to sizeof(struct module_stat) */ 366 char name[MAXMODNAME]; 367 int refs; 368 int id; 369 }; 370 371 int 372 sys_modstat(struct thread *td, struct modstat_args *uap) 373 { 374 module_t mod; 375 modspecific_t data; 376 int error = 0; 377 int id, namelen, refs, version; 378 struct module_stat *stat; 379 char *name; 380 381 MOD_SLOCK; 382 mod = module_lookupbyid(uap->modid); 383 if (mod == NULL) { 384 MOD_SUNLOCK; 385 return (ENOENT); 386 } 387 id = mod->id; 388 refs = mod->refs; 389 name = mod->name; 390 data = mod->data; 391 MOD_SUNLOCK; 392 stat = uap->stat; 393 394 /* 395 * Check the version of the user's structure. 396 */ 397 if ((error = copyin(&stat->version, &version, sizeof(version))) != 0) 398 return (error); 399 if (version != sizeof(struct module_stat_v1) 400 && version != sizeof(struct module_stat)) 401 return (EINVAL); 402 namelen = strlen(mod->name) + 1; 403 if (namelen > MAXMODNAME) 404 namelen = MAXMODNAME; 405 if ((error = copyout(name, &stat->name[0], namelen)) != 0) 406 return (error); 407 408 if ((error = copyout(&refs, &stat->refs, sizeof(int))) != 0) 409 return (error); 410 if ((error = copyout(&id, &stat->id, sizeof(int))) != 0) 411 return (error); 412 413 /* 414 * >v1 stat includes module data. 415 */ 416 if (version == sizeof(struct module_stat)) 417 if ((error = copyout(&data, &stat->data, 418 sizeof(data))) != 0) 419 return (error); 420 td->td_retval[0] = 0; 421 return (error); 422 } 423 424 int 425 sys_modfind(struct thread *td, struct modfind_args *uap) 426 { 427 int error = 0; 428 char name[MAXMODNAME]; 429 module_t mod; 430 431 if ((error = copyinstr(uap->name, name, sizeof name, 0)) != 0) 432 return (error); 433 434 MOD_SLOCK; 435 mod = module_lookupbyname(name); 436 if (mod == NULL) 437 error = ENOENT; 438 else 439 td->td_retval[0] = module_getid(mod); 440 MOD_SUNLOCK; 441 return (error); 442 } 443 444 MODULE_VERSION(kernel, __FreeBSD_version); 445 446 #ifdef COMPAT_FREEBSD32 447 #include <sys/mount.h> 448 #include <sys/socket.h> 449 #include <compat/freebsd32/freebsd32_util.h> 450 #include <compat/freebsd32/freebsd32.h> 451 #include <compat/freebsd32/freebsd32_proto.h> 452 453 typedef union modspecific32 { 454 int intval; 455 uint32_t uintval; 456 int longval; 457 uint32_t ulongval; 458 } modspecific32_t; 459 460 struct module_stat32 { 461 int version; 462 char name[MAXMODNAME]; 463 int refs; 464 int id; 465 modspecific32_t data; 466 }; 467 468 int 469 freebsd32_modstat(struct thread *td, struct freebsd32_modstat_args *uap) 470 { 471 module_t mod; 472 modspecific32_t data32; 473 int error = 0; 474 int id, namelen, refs, version; 475 struct module_stat32 *stat32; 476 char *name; 477 478 MOD_SLOCK; 479 mod = module_lookupbyid(uap->modid); 480 if (mod == NULL) { 481 MOD_SUNLOCK; 482 return (ENOENT); 483 } 484 485 id = mod->id; 486 refs = mod->refs; 487 name = mod->name; 488 CP(mod->data, data32, intval); 489 CP(mod->data, data32, uintval); 490 CP(mod->data, data32, longval); 491 CP(mod->data, data32, ulongval); 492 MOD_SUNLOCK; 493 stat32 = uap->stat; 494 495 if ((error = copyin(&stat32->version, &version, sizeof(version))) != 0) 496 return (error); 497 if (version != sizeof(struct module_stat_v1) 498 && version != sizeof(struct module_stat32)) 499 return (EINVAL); 500 namelen = strlen(mod->name) + 1; 501 if (namelen > MAXMODNAME) 502 namelen = MAXMODNAME; 503 if ((error = copyout(name, &stat32->name[0], namelen)) != 0) 504 return (error); 505 506 if ((error = copyout(&refs, &stat32->refs, sizeof(int))) != 0) 507 return (error); 508 if ((error = copyout(&id, &stat32->id, sizeof(int))) != 0) 509 return (error); 510 511 /* 512 * >v1 stat includes module data. 513 */ 514 if (version == sizeof(struct module_stat32)) 515 if ((error = copyout(&data32, &stat32->data, 516 sizeof(data32))) != 0) 517 return (error); 518 td->td_retval[0] = 0; 519 return (error); 520 } 521 #endif 522