1 /*- 2 * Copyright (c) 1997 Doug Rabson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include "opt_compat.h" 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, 0); 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 succesfully 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("module_register: module %s already exists!\n", 162 data->name); 163 return (EEXIST); 164 } 165 namelen = strlen(data->name) + 1; 166 newmod = malloc(sizeof(struct module) + namelen, M_MODULE, M_WAITOK); 167 if (newmod == NULL) { 168 MOD_XUNLOCK; 169 return (ENOMEM); 170 } 171 newmod->refs = 1; 172 newmod->id = nextid++; 173 newmod->name = (char *)(newmod + 1); 174 strcpy(newmod->name, data->name); 175 newmod->handler = data->evhand ? data->evhand : modevent_nop; 176 newmod->arg = data->priv; 177 bzero(&newmod->data, sizeof(newmod->data)); 178 TAILQ_INSERT_TAIL(&modules, newmod, link); 179 180 if (container) 181 TAILQ_INSERT_TAIL(&container->modules, newmod, flink); 182 newmod->file = container; 183 MOD_XUNLOCK; 184 return (0); 185 } 186 187 void 188 module_reference(module_t mod) 189 { 190 191 MOD_XLOCK_ASSERT; 192 193 MOD_DPF(REFS, ("module_reference: before, refs=%d\n", mod->refs)); 194 mod->refs++; 195 } 196 197 void 198 module_release(module_t mod) 199 { 200 201 MOD_XLOCK_ASSERT; 202 203 if (mod->refs <= 0) 204 panic("module_release: bad reference count"); 205 206 MOD_DPF(REFS, ("module_release: before, refs=%d\n", mod->refs)); 207 208 mod->refs--; 209 if (mod->refs == 0) { 210 TAILQ_REMOVE(&modules, mod, link); 211 if (mod->file) 212 TAILQ_REMOVE(&mod->file->modules, mod, flink); 213 free(mod, M_MODULE); 214 } 215 } 216 217 module_t 218 module_lookupbyname(const char *name) 219 { 220 module_t mod; 221 int err; 222 223 MOD_LOCK_ASSERT; 224 225 TAILQ_FOREACH(mod, &modules, link) { 226 err = strcmp(mod->name, name); 227 if (err == 0) 228 return (mod); 229 } 230 return (NULL); 231 } 232 233 module_t 234 module_lookupbyid(int modid) 235 { 236 module_t mod; 237 238 MOD_LOCK_ASSERT; 239 240 TAILQ_FOREACH(mod, &modules, link) 241 if (mod->id == modid) 242 return(mod); 243 return (NULL); 244 } 245 246 int 247 module_quiesce(module_t mod) 248 { 249 int error; 250 251 mtx_lock(&Giant); 252 error = MOD_EVENT(mod, MOD_QUIESCE); 253 mtx_unlock(&Giant); 254 if (error == EOPNOTSUPP || error == EINVAL) 255 error = 0; 256 return (error); 257 } 258 259 int 260 module_unload(module_t mod) 261 { 262 int error; 263 264 mtx_lock(&Giant); 265 error = MOD_EVENT(mod, MOD_UNLOAD); 266 mtx_unlock(&Giant); 267 return (error); 268 } 269 270 int 271 module_getid(module_t mod) 272 { 273 274 MOD_LOCK_ASSERT; 275 return (mod->id); 276 } 277 278 module_t 279 module_getfnext(module_t mod) 280 { 281 282 MOD_LOCK_ASSERT; 283 return (TAILQ_NEXT(mod, flink)); 284 } 285 286 const char * 287 module_getname(module_t mod) 288 { 289 290 MOD_LOCK_ASSERT; 291 return (mod->name); 292 } 293 294 void 295 module_setspecific(module_t mod, modspecific_t *datap) 296 { 297 298 MOD_XLOCK_ASSERT; 299 mod->data = *datap; 300 } 301 302 linker_file_t 303 module_file(module_t mod) 304 { 305 306 return (mod->file); 307 } 308 309 /* 310 * Syscalls. 311 */ 312 int 313 sys_modnext(struct thread *td, struct modnext_args *uap) 314 { 315 module_t mod; 316 int error = 0; 317 318 td->td_retval[0] = -1; 319 320 MOD_SLOCK; 321 if (uap->modid == 0) { 322 mod = TAILQ_FIRST(&modules); 323 if (mod) 324 td->td_retval[0] = mod->id; 325 else 326 error = ENOENT; 327 goto done2; 328 } 329 mod = module_lookupbyid(uap->modid); 330 if (mod == NULL) { 331 error = ENOENT; 332 goto done2; 333 } 334 if (TAILQ_NEXT(mod, link)) 335 td->td_retval[0] = TAILQ_NEXT(mod, link)->id; 336 else 337 td->td_retval[0] = 0; 338 done2: 339 MOD_SUNLOCK; 340 return (error); 341 } 342 343 int 344 sys_modfnext(struct thread *td, struct modfnext_args *uap) 345 { 346 module_t mod; 347 int error; 348 349 td->td_retval[0] = -1; 350 351 MOD_SLOCK; 352 mod = module_lookupbyid(uap->modid); 353 if (mod == NULL) { 354 error = ENOENT; 355 } else { 356 error = 0; 357 if (TAILQ_NEXT(mod, flink)) 358 td->td_retval[0] = TAILQ_NEXT(mod, flink)->id; 359 else 360 td->td_retval[0] = 0; 361 } 362 MOD_SUNLOCK; 363 return (error); 364 } 365 366 struct module_stat_v1 { 367 int version; /* set to sizeof(struct module_stat) */ 368 char name[MAXMODNAME]; 369 int refs; 370 int id; 371 }; 372 373 int 374 sys_modstat(struct thread *td, struct modstat_args *uap) 375 { 376 module_t mod; 377 modspecific_t data; 378 int error = 0; 379 int id, namelen, refs, version; 380 struct module_stat *stat; 381 char *name; 382 383 MOD_SLOCK; 384 mod = module_lookupbyid(uap->modid); 385 if (mod == NULL) { 386 MOD_SUNLOCK; 387 return (ENOENT); 388 } 389 id = mod->id; 390 refs = mod->refs; 391 name = mod->name; 392 data = mod->data; 393 MOD_SUNLOCK; 394 stat = uap->stat; 395 396 /* 397 * Check the version of the user's structure. 398 */ 399 if ((error = copyin(&stat->version, &version, sizeof(version))) != 0) 400 return (error); 401 if (version != sizeof(struct module_stat_v1) 402 && version != sizeof(struct module_stat)) 403 return (EINVAL); 404 namelen = strlen(mod->name) + 1; 405 if (namelen > MAXMODNAME) 406 namelen = MAXMODNAME; 407 if ((error = copyout(name, &stat->name[0], namelen)) != 0) 408 return (error); 409 410 if ((error = copyout(&refs, &stat->refs, sizeof(int))) != 0) 411 return (error); 412 if ((error = copyout(&id, &stat->id, sizeof(int))) != 0) 413 return (error); 414 415 /* 416 * >v1 stat includes module data. 417 */ 418 if (version == sizeof(struct module_stat)) 419 if ((error = copyout(&data, &stat->data, 420 sizeof(data))) != 0) 421 return (error); 422 td->td_retval[0] = 0; 423 return (error); 424 } 425 426 int 427 sys_modfind(struct thread *td, struct modfind_args *uap) 428 { 429 int error = 0; 430 char name[MAXMODNAME]; 431 module_t mod; 432 433 if ((error = copyinstr(uap->name, name, sizeof name, 0)) != 0) 434 return (error); 435 436 MOD_SLOCK; 437 mod = module_lookupbyname(name); 438 if (mod == NULL) 439 error = ENOENT; 440 else 441 td->td_retval[0] = module_getid(mod); 442 MOD_SUNLOCK; 443 return (error); 444 } 445 446 MODULE_VERSION(kernel, __FreeBSD_version); 447 448 #ifdef COMPAT_FREEBSD32 449 #include <sys/mount.h> 450 #include <sys/socket.h> 451 #include <compat/freebsd32/freebsd32_util.h> 452 #include <compat/freebsd32/freebsd32.h> 453 #include <compat/freebsd32/freebsd32_proto.h> 454 455 typedef union modspecific32 { 456 int intval; 457 uint32_t uintval; 458 int longval; 459 uint32_t ulongval; 460 } modspecific32_t; 461 462 struct module_stat32 { 463 int version; 464 char name[MAXMODNAME]; 465 int refs; 466 int id; 467 modspecific32_t data; 468 }; 469 470 int 471 freebsd32_modstat(struct thread *td, struct freebsd32_modstat_args *uap) 472 { 473 module_t mod; 474 modspecific32_t data32; 475 int error = 0; 476 int id, namelen, refs, version; 477 struct module_stat32 *stat32; 478 char *name; 479 480 MOD_SLOCK; 481 mod = module_lookupbyid(uap->modid); 482 if (mod == NULL) { 483 MOD_SUNLOCK; 484 return (ENOENT); 485 } 486 487 id = mod->id; 488 refs = mod->refs; 489 name = mod->name; 490 CP(mod->data, data32, intval); 491 CP(mod->data, data32, uintval); 492 CP(mod->data, data32, longval); 493 CP(mod->data, data32, ulongval); 494 MOD_SUNLOCK; 495 stat32 = uap->stat; 496 497 if ((error = copyin(&stat32->version, &version, sizeof(version))) != 0) 498 return (error); 499 if (version != sizeof(struct module_stat_v1) 500 && version != sizeof(struct module_stat32)) 501 return (EINVAL); 502 namelen = strlen(mod->name) + 1; 503 if (namelen > MAXMODNAME) 504 namelen = MAXMODNAME; 505 if ((error = copyout(name, &stat32->name[0], namelen)) != 0) 506 return (error); 507 508 if ((error = copyout(&refs, &stat32->refs, sizeof(int))) != 0) 509 return (error); 510 if ((error = copyout(&id, &stat32->id, sizeof(int))) != 0) 511 return (error); 512 513 /* 514 * >v1 stat includes module data. 515 */ 516 if (version == sizeof(struct module_stat32)) 517 if ((error = copyout(&data32, &stat32->data, 518 sizeof(data32))) != 0) 519 return (error); 520 td->td_retval[0] = 0; 521 return (error); 522 } 523 #endif 524