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 <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/kernel.h> 32 #include <sys/systm.h> 33 #include <sys/eventhandler.h> 34 #include <sys/malloc.h> 35 #include <sys/sysproto.h> 36 #include <sys/sysent.h> 37 #include <sys/proc.h> 38 #include <sys/lock.h> 39 #include <sys/mutex.h> 40 #include <sys/reboot.h> 41 #include <sys/sx.h> 42 #include <sys/module.h> 43 #include <sys/linker.h> 44 45 static MALLOC_DEFINE(M_MODULE, "module", "module data structures"); 46 47 typedef TAILQ_HEAD(, module) modulelist_t; 48 struct module { 49 TAILQ_ENTRY(module) link; /* chain together all modules */ 50 TAILQ_ENTRY(module) flink; /* all modules in a file */ 51 struct linker_file *file; /* file which contains this module */ 52 int refs; /* reference count */ 53 int id; /* unique id number */ 54 char *name; /* module name */ 55 modeventhand_t handler; /* event handler */ 56 void *arg; /* argument for handler */ 57 modspecific_t data; /* module specific data */ 58 }; 59 60 #define MOD_EVENT(mod, type) (mod)->handler((mod), (type), (mod)->arg) 61 62 static modulelist_t modules; 63 struct sx modules_sx; 64 static int nextid = 1; 65 static void module_shutdown(void *, int); 66 67 static int 68 modevent_nop(module_t mod, int what, void *arg) 69 { 70 71 switch(what) { 72 case MOD_LOAD: 73 return (0); 74 case MOD_UNLOAD: 75 return (EBUSY); 76 default: 77 return (EOPNOTSUPP); 78 } 79 } 80 81 static void 82 module_init(void *arg) 83 { 84 85 sx_init(&modules_sx, "module subsystem sx lock"); 86 TAILQ_INIT(&modules); 87 EVENTHANDLER_REGISTER(shutdown_final, module_shutdown, NULL, 88 SHUTDOWN_PRI_DEFAULT); 89 } 90 91 SYSINIT(module, SI_SUB_KLD, SI_ORDER_FIRST, module_init, 0) 92 93 static void 94 module_shutdown(void *arg1, int arg2) 95 { 96 module_t mod; 97 98 if (arg2 & RB_NOSYNC) 99 return; 100 MOD_SLOCK; 101 TAILQ_FOREACH(mod, &modules, link) 102 MOD_EVENT(mod, MOD_SHUTDOWN); 103 MOD_SUNLOCK; 104 } 105 106 void 107 module_register_init(const void *arg) 108 { 109 const moduledata_t *data = (const moduledata_t *)arg; 110 int error; 111 module_t mod; 112 113 MOD_SLOCK; 114 mod = module_lookupbyname(data->name); 115 if (mod == NULL) 116 panic("module_register_init: module named %s not found\n", 117 data->name); 118 MOD_SUNLOCK; 119 error = MOD_EVENT(mod, MOD_LOAD); 120 if (error) { 121 MOD_EVENT(mod, MOD_UNLOAD); 122 MOD_XLOCK; 123 module_release(mod); 124 MOD_XUNLOCK; 125 printf("module_register_init: MOD_LOAD (%s, %p, %p) error" 126 " %d\n", data->name, (void *)data->evhand, data->priv, 127 error); 128 } 129 } 130 131 int 132 module_register(const moduledata_t *data, linker_file_t container) 133 { 134 size_t namelen; 135 module_t newmod; 136 137 MOD_SLOCK; 138 newmod = module_lookupbyname(data->name); 139 if (newmod != NULL) { 140 MOD_SUNLOCK; 141 printf("module_register: module %s already exists!\n", 142 data->name); 143 return (EEXIST); 144 } 145 MOD_SUNLOCK; 146 namelen = strlen(data->name) + 1; 147 newmod = malloc(sizeof(struct module) + namelen, M_MODULE, M_WAITOK); 148 if (newmod == NULL) 149 return (ENOMEM); 150 MOD_XLOCK; 151 newmod->refs = 1; 152 newmod->id = nextid++; 153 newmod->name = (char *)(newmod + 1); 154 strcpy(newmod->name, data->name); 155 newmod->handler = data->evhand ? data->evhand : modevent_nop; 156 newmod->arg = data->priv; 157 bzero(&newmod->data, sizeof(newmod->data)); 158 TAILQ_INSERT_TAIL(&modules, newmod, link); 159 160 if (container) 161 TAILQ_INSERT_TAIL(&container->modules, newmod, flink); 162 newmod->file = container; 163 MOD_XUNLOCK; 164 return (0); 165 } 166 167 void 168 module_reference(module_t mod) 169 { 170 171 MOD_XLOCK_ASSERT; 172 173 MOD_DPF(REFS, ("module_reference: before, refs=%d\n", mod->refs)); 174 mod->refs++; 175 } 176 177 void 178 module_release(module_t mod) 179 { 180 181 MOD_XLOCK_ASSERT; 182 183 if (mod->refs <= 0) 184 panic("module_release: bad reference count"); 185 186 MOD_DPF(REFS, ("module_release: before, refs=%d\n", mod->refs)); 187 188 mod->refs--; 189 if (mod->refs == 0) { 190 TAILQ_REMOVE(&modules, mod, link); 191 if (mod->file) 192 TAILQ_REMOVE(&mod->file->modules, mod, flink); 193 MOD_XUNLOCK; 194 free(mod, M_MODULE); 195 MOD_XLOCK; 196 } 197 } 198 199 module_t 200 module_lookupbyname(const char *name) 201 { 202 module_t mod; 203 int err; 204 205 MOD_LOCK_ASSERT; 206 207 TAILQ_FOREACH(mod, &modules, link) { 208 err = strcmp(mod->name, name); 209 if (err == 0) 210 return (mod); 211 } 212 return (NULL); 213 } 214 215 module_t 216 module_lookupbyid(int modid) 217 { 218 module_t mod; 219 220 MOD_LOCK_ASSERT; 221 222 TAILQ_FOREACH(mod, &modules, link) 223 if (mod->id == modid) 224 return(mod); 225 return (NULL); 226 } 227 228 int 229 module_unload(module_t mod, int flags) 230 { 231 int error; 232 233 error = MOD_EVENT(mod, MOD_QUIESCE); 234 if (error == EOPNOTSUPP || error == EINVAL) 235 error = 0; 236 if (flags == LINKER_UNLOAD_NORMAL && error != 0) 237 return (error); 238 return (MOD_EVENT(mod, MOD_UNLOAD)); 239 } 240 241 int 242 module_getid(module_t mod) 243 { 244 245 MOD_LOCK_ASSERT; 246 return (mod->id); 247 } 248 249 module_t 250 module_getfnext(module_t mod) 251 { 252 253 MOD_LOCK_ASSERT; 254 return (TAILQ_NEXT(mod, flink)); 255 } 256 257 void 258 module_setspecific(module_t mod, modspecific_t *datap) 259 { 260 261 MOD_XLOCK_ASSERT; 262 mod->data = *datap; 263 } 264 265 /* 266 * Syscalls. 267 */ 268 /* 269 * MPSAFE 270 */ 271 int 272 modnext(struct thread *td, struct modnext_args *uap) 273 { 274 module_t mod; 275 int error = 0; 276 277 td->td_retval[0] = -1; 278 279 MOD_SLOCK; 280 if (uap->modid == 0) { 281 mod = TAILQ_FIRST(&modules); 282 if (mod) 283 td->td_retval[0] = mod->id; 284 else 285 error = ENOENT; 286 goto done2; 287 } 288 mod = module_lookupbyid(uap->modid); 289 if (mod == NULL) { 290 error = ENOENT; 291 goto done2; 292 } 293 if (TAILQ_NEXT(mod, link)) 294 td->td_retval[0] = TAILQ_NEXT(mod, link)->id; 295 else 296 td->td_retval[0] = 0; 297 done2: 298 MOD_SUNLOCK; 299 return (error); 300 } 301 302 /* 303 * MPSAFE 304 */ 305 int 306 modfnext(struct thread *td, struct modfnext_args *uap) 307 { 308 module_t mod; 309 int error; 310 311 td->td_retval[0] = -1; 312 313 MOD_SLOCK; 314 mod = module_lookupbyid(uap->modid); 315 if (mod == NULL) { 316 error = ENOENT; 317 } else { 318 error = 0; 319 if (TAILQ_NEXT(mod, flink)) 320 td->td_retval[0] = TAILQ_NEXT(mod, flink)->id; 321 else 322 td->td_retval[0] = 0; 323 } 324 MOD_SUNLOCK; 325 return (error); 326 } 327 328 struct module_stat_v1 { 329 int version; /* set to sizeof(struct module_stat) */ 330 char name[MAXMODNAME]; 331 int refs; 332 int id; 333 }; 334 335 /* 336 * MPSAFE 337 */ 338 int 339 modstat(struct thread *td, struct modstat_args *uap) 340 { 341 module_t mod; 342 modspecific_t data; 343 int error = 0; 344 int id, namelen, refs, version; 345 struct module_stat *stat; 346 char *name; 347 348 MOD_SLOCK; 349 mod = module_lookupbyid(uap->modid); 350 if (mod == NULL) { 351 MOD_SUNLOCK; 352 return (ENOENT); 353 } 354 id = mod->id; 355 refs = mod->refs; 356 name = mod->name; 357 data = mod->data; 358 MOD_SUNLOCK; 359 stat = uap->stat; 360 361 /* 362 * Check the version of the user's structure. 363 */ 364 if ((error = copyin(&stat->version, &version, sizeof(version))) != 0) 365 return (error); 366 if (version != sizeof(struct module_stat_v1) 367 && version != sizeof(struct module_stat)) 368 return (EINVAL); 369 namelen = strlen(mod->name) + 1; 370 if (namelen > MAXMODNAME) 371 namelen = MAXMODNAME; 372 if ((error = copyout(name, &stat->name[0], namelen)) != 0) 373 return (error); 374 375 if ((error = copyout(&refs, &stat->refs, sizeof(int))) != 0) 376 return (error); 377 if ((error = copyout(&id, &stat->id, sizeof(int))) != 0) 378 return (error); 379 380 /* 381 * >v1 stat includes module data. 382 */ 383 if (version == sizeof(struct module_stat)) 384 if ((error = copyout(&data, &stat->data, 385 sizeof(data))) != 0) 386 return (error); 387 td->td_retval[0] = 0; 388 return (error); 389 } 390 391 /* 392 * MPSAFE 393 */ 394 int 395 modfind(struct thread *td, struct modfind_args *uap) 396 { 397 int error = 0; 398 char name[MAXMODNAME]; 399 module_t mod; 400 401 if ((error = copyinstr(uap->name, name, sizeof name, 0)) != 0) 402 return (error); 403 404 MOD_SLOCK; 405 mod = module_lookupbyname(name); 406 if (mod == NULL) 407 error = ENOENT; 408 else 409 td->td_retval[0] = module_getid(mod); 410 MOD_SUNLOCK; 411 return (error); 412 } 413