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 * $FreeBSD: src/sys/kern/kern_module.c,v 1.21 1999/11/08 06:53:30 peter Exp $ 27 */ 28 29 #include <sys/param.h> 30 #include <sys/kernel.h> 31 #include <sys/systm.h> 32 #include <sys/eventhandler.h> 33 #include <sys/malloc.h> 34 #include <sys/sysmsg.h> 35 #include <sys/sysent.h> 36 #include <sys/module.h> 37 #include <sys/linker.h> 38 #include <sys/proc.h> 39 40 MALLOC_DEFINE(M_MODULE, "module", "module data structures"); 41 42 typedef TAILQ_HEAD(, module) modulelist_t; 43 struct module { 44 TAILQ_ENTRY(module) link; /* chain together all modules */ 45 TAILQ_ENTRY(module) flink; /* all modules in a file */ 46 struct linker_file* file; /* file which contains this module */ 47 int refs; /* reference count */ 48 int id; /* unique id number */ 49 char *name; /* module name */ 50 modeventhand_t handler; /* event handler */ 51 void *arg; /* argument for handler */ 52 modspecific_t data; /* module specific data */ 53 }; 54 55 #define MOD_EVENT(mod, type) (mod)->handler((mod), (type), (mod)->arg) 56 57 static modulelist_t modules = TAILQ_HEAD_INITIALIZER(modules); 58 static struct lwkt_token mod_token = LWKT_TOKEN_INITIALIZER(mod_token); 59 static int nextid = 1; 60 61 static void module_shutdown(void*, int); 62 63 static int 64 modevent_nop(module_t mod, int what, void* arg) 65 { 66 return 0; 67 } 68 69 70 static void 71 module_init(void* arg) 72 { 73 TAILQ_INIT(&modules); 74 EVENTHANDLER_REGISTER(shutdown_post_sync, module_shutdown, NULL, 75 SHUTDOWN_PRI_DEFAULT); 76 } 77 78 SYSINIT(module, SI_BOOT2_KLD, SI_ORDER_FIRST, module_init, 0); 79 80 static void 81 module_shutdown(void* arg1, int arg2) 82 { 83 module_t mod; 84 85 for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link)) 86 MOD_EVENT(mod, MOD_SHUTDOWN); 87 } 88 89 void 90 module_register_init(const void *arg) 91 { 92 const moduledata_t* data = (const moduledata_t*) arg; 93 int error; 94 module_t mod; 95 96 mod = module_lookupbyname(data->name); 97 if (mod == NULL) { 98 #if 0 99 panic("module_register_init: module named %s not found", data->name); 100 #else 101 /* temporary kludge until kernel `file' attachment registers modules */ 102 error = module_register(data, linker_kernel_file); 103 if (error) 104 panic("module_register_init: register of module failed! %d", error); 105 mod = module_lookupbyname(data->name); 106 if (mod == NULL) 107 panic("module_register_init: module STILL not found!"); 108 #endif 109 } 110 error = MOD_EVENT(mod, MOD_LOAD); 111 if (error) { 112 module_unload(mod); /* ignore error */ 113 module_release(mod); 114 kprintf("module_register_init: MOD_LOAD (%s, %lx, %p) error %d\n", 115 data->name, (u_long)data->evhand, data->priv, error); 116 } 117 } 118 119 int 120 module_register(const moduledata_t *data, linker_file_t container) 121 { 122 size_t namelen; 123 module_t newmod; 124 125 newmod = module_lookupbyname(data->name); 126 if (newmod != NULL) { 127 kprintf("module_register: module %s already exists!\n", data->name); 128 return EEXIST; 129 } 130 namelen = strlen(data->name) + 1; 131 newmod = (module_t) kmalloc(sizeof(struct module) + namelen, 132 M_MODULE, M_WAITOK); 133 134 newmod->refs = 1; 135 newmod->id = nextid++; 136 newmod->name = (char *) (newmod + 1); 137 strcpy(newmod->name, data->name); 138 newmod->handler = data->evhand ? data->evhand : modevent_nop; 139 newmod->arg = data->priv; 140 bzero(&newmod->data, sizeof(newmod->data)); 141 TAILQ_INSERT_TAIL(&modules, newmod, link); 142 143 if (container == NULL) 144 container = linker_current_file; 145 if (container) 146 TAILQ_INSERT_TAIL(&container->modules, newmod, flink); 147 newmod->file = container; 148 149 return 0; 150 } 151 152 void 153 module_reference(module_t mod) 154 { 155 MOD_DPF(REFS, ("module_reference: before, refs=%d\n", mod->refs)); 156 157 mod->refs++; 158 } 159 160 /* 161 * module_release() 162 * 163 * Release ref on the module and return the new reference count. If 0 164 * is returned, the module has been removed from its list and freed. 165 */ 166 int 167 module_release(module_t mod) 168 { 169 int rc; 170 171 if (mod->refs <= 0) 172 panic("module_release: bad reference count"); 173 174 MOD_DPF(REFS, ("module_release: before, refs=%d\n", mod->refs)); 175 176 rc = --mod->refs; 177 if (rc == 0) { 178 TAILQ_REMOVE(&modules, mod, link); 179 if (mod->file) { 180 TAILQ_REMOVE(&mod->file->modules, mod, flink); 181 } 182 kfree(mod, M_MODULE); 183 } 184 return(rc); 185 } 186 187 module_t 188 module_lookupbyname(const char* name) 189 { 190 module_t mod; 191 192 for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link)) { 193 if (!strcmp(mod->name, name)) 194 return mod; 195 } 196 197 return NULL; 198 } 199 200 module_t 201 module_lookupbyid(int modid) 202 { 203 module_t mod; 204 205 for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link)) { 206 if (mod->id == modid) 207 return mod; 208 } 209 210 return NULL; 211 } 212 213 int 214 module_unload(module_t mod) 215 { 216 int error; 217 218 error = MOD_EVENT(mod, MOD_UNLOAD); 219 /*sync_devs();*/ 220 return (error); 221 } 222 223 int 224 module_getid(module_t mod) 225 { 226 return mod->id; 227 } 228 229 module_t 230 module_getfnext(module_t mod) 231 { 232 return TAILQ_NEXT(mod, flink); 233 } 234 235 void 236 module_setspecific(module_t mod, modspecific_t *datap) 237 { 238 mod->data = *datap; 239 } 240 241 /* 242 * Syscalls. 243 * 244 * MPALMOSTSAFE 245 */ 246 int 247 sys_modnext(struct sysmsg *sysmsg, const struct modnext_args *uap) 248 { 249 module_t mod; 250 int error; 251 252 error = 0; 253 lwkt_gettoken(&mod_token); 254 sysmsg->sysmsg_result = -1; 255 if (uap->modid == 0) { 256 mod = TAILQ_FIRST(&modules); 257 if (mod) 258 sysmsg->sysmsg_result = mod->id; 259 else 260 error = ENOENT; 261 goto done; 262 } 263 264 mod = module_lookupbyid(uap->modid); 265 if (!mod) { 266 error = ENOENT; 267 goto done; 268 } 269 270 if (TAILQ_NEXT(mod, link)) 271 sysmsg->sysmsg_result = TAILQ_NEXT(mod, link)->id; 272 else 273 sysmsg->sysmsg_result = 0; 274 done: 275 lwkt_reltoken(&mod_token); 276 277 return error; 278 } 279 280 /* 281 * MPALMOSTSAFE 282 */ 283 int 284 sys_modfnext(struct sysmsg *sysmsg, const struct modfnext_args *uap) 285 { 286 module_t mod; 287 int error; 288 289 lwkt_gettoken(&mod_token); 290 sysmsg->sysmsg_result = -1; 291 292 mod = module_lookupbyid(uap->modid); 293 if (!mod) { 294 error = ENOENT; 295 goto done; 296 } 297 298 if (TAILQ_NEXT(mod, flink)) 299 sysmsg->sysmsg_result = TAILQ_NEXT(mod, flink)->id; 300 else 301 sysmsg->sysmsg_result = 0; 302 error = 0; 303 done: 304 lwkt_reltoken(&mod_token); 305 306 return error; 307 } 308 309 struct module_stat_v1 { 310 int version; /* set to sizeof(struct module_stat) */ 311 char name[MAXMODNAME]; 312 int refs; 313 int id; 314 }; 315 316 /* 317 * MPALMOSTSAFE 318 */ 319 int 320 sys_modstat(struct sysmsg *sysmsg, const struct modstat_args *uap) 321 { 322 module_t mod; 323 int error; 324 int namelen; 325 int version; 326 struct module_stat* stat; 327 328 lwkt_gettoken(&mod_token); 329 mod = module_lookupbyid(uap->modid); 330 if (!mod) { 331 error = ENOENT; 332 goto out; 333 } 334 335 stat = uap->stat; 336 337 /* 338 * Check the version of the user's structure. 339 */ 340 if ((error = copyin(&stat->version, &version, sizeof(version))) != 0) 341 goto out; 342 if (version != sizeof(struct module_stat_v1) 343 && version != sizeof(struct module_stat)) { 344 error = EINVAL; 345 goto out; 346 } 347 348 namelen = strlen(mod->name) + 1; 349 if (namelen > MAXMODNAME) 350 namelen = MAXMODNAME; 351 if ((error = copyout(mod->name, &stat->name[0], namelen)) != 0) 352 goto out; 353 354 if ((error = copyout(&mod->refs, &stat->refs, sizeof(int))) != 0) 355 goto out; 356 if ((error = copyout(&mod->id, &stat->id, sizeof(int))) != 0) 357 goto out; 358 359 /* 360 * >v1 stat includes module data. 361 */ 362 if (version == sizeof(struct module_stat)) { 363 if ((error = copyout(&mod->data, &stat->data, sizeof(mod->data))) != 0) 364 goto out; 365 } 366 367 sysmsg->sysmsg_result = 0; 368 369 out: 370 lwkt_reltoken(&mod_token); 371 372 return error; 373 } 374 375 /* 376 * MPALMOSTSAFE 377 */ 378 int 379 sys_modfind(struct sysmsg *sysmsg, const struct modfind_args *uap) 380 { 381 int error; 382 char name[MAXMODNAME]; 383 module_t mod; 384 385 lwkt_gettoken(&mod_token); 386 if ((error = copyinstr(uap->name, name, sizeof name, 0)) != 0) 387 goto out; 388 389 mod = module_lookupbyname(name); 390 if (!mod) 391 error = ENOENT; 392 else 393 sysmsg->sysmsg_result = mod->id; 394 395 out: 396 lwkt_reltoken(&mod_token); 397 398 return error; 399 } 400