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 * $DragonFly: src/sys/kern/kern_module.c,v 1.16 2008/06/07 11:44:04 mneumann Exp $ 28 */ 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/module.h> 38 #include <sys/linker.h> 39 #include <sys/proc.h> 40 41 MALLOC_DEFINE(M_MODULE, "module", "module data structures"); 42 43 typedef TAILQ_HEAD(, module) modulelist_t; 44 struct module { 45 TAILQ_ENTRY(module) link; /* chain together all modules */ 46 TAILQ_ENTRY(module) flink; /* all modules in a file */ 47 struct linker_file* file; /* file which contains this module */ 48 int refs; /* reference count */ 49 int id; /* unique id number */ 50 char *name; /* module name */ 51 modeventhand_t handler; /* event handler */ 52 void *arg; /* argument for handler */ 53 modspecific_t data; /* module specific data */ 54 }; 55 56 #define MOD_EVENT(mod, type) (mod)->handler((mod), (type), (mod)->arg) 57 58 static modulelist_t modules = TAILQ_HEAD_INITIALIZER(modules); 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)(uintfptr_t)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 modnext_args *uap) 248 { 249 module_t mod; 250 int error; 251 252 get_mplock(); 253 uap->sysmsg_result = -1; 254 if (uap->modid == 0) { 255 mod = TAILQ_FIRST(&modules); 256 if (mod) { 257 uap->sysmsg_result = mod->id; 258 error = 0; 259 goto done; 260 } else { 261 error = ENOENT; 262 goto done; 263 } 264 } 265 266 mod = module_lookupbyid(uap->modid); 267 if (!mod) { 268 error = ENOENT; 269 goto done; 270 } 271 272 if (TAILQ_NEXT(mod, link)) 273 uap->sysmsg_result = TAILQ_NEXT(mod, link)->id; 274 else 275 uap->sysmsg_result = 0; 276 error = 0; 277 done: 278 rel_mplock(); 279 return error; 280 } 281 282 /* 283 * MPALMOSTSAFE 284 */ 285 int 286 sys_modfnext(struct modfnext_args *uap) 287 { 288 module_t mod; 289 int error; 290 291 get_mplock(); 292 uap->sysmsg_result = -1; 293 294 mod = module_lookupbyid(uap->modid); 295 if (!mod) { 296 error = ENOENT; 297 goto done; 298 } 299 300 if (TAILQ_NEXT(mod, flink)) 301 uap->sysmsg_result = TAILQ_NEXT(mod, flink)->id; 302 else 303 uap->sysmsg_result = 0; 304 error = 0; 305 done: 306 rel_mplock(); 307 return error; 308 } 309 310 struct module_stat_v1 { 311 int version; /* set to sizeof(struct module_stat) */ 312 char name[MAXMODNAME]; 313 int refs; 314 int id; 315 }; 316 317 /* 318 * MPALMOSTSAFE 319 */ 320 int 321 sys_modstat(struct modstat_args *uap) 322 { 323 module_t mod; 324 int error; 325 int namelen; 326 int version; 327 struct module_stat* stat; 328 329 get_mplock(); 330 mod = module_lookupbyid(uap->modid); 331 if (!mod) { 332 error = ENOENT; 333 goto out; 334 } 335 336 stat = uap->stat; 337 338 /* 339 * Check the version of the user's structure. 340 */ 341 if ((error = copyin(&stat->version, &version, sizeof(version))) != 0) 342 goto out; 343 if (version != sizeof(struct module_stat_v1) 344 && version != sizeof(struct module_stat)) { 345 error = EINVAL; 346 goto out; 347 } 348 349 namelen = strlen(mod->name) + 1; 350 if (namelen > MAXMODNAME) 351 namelen = MAXMODNAME; 352 if ((error = copyout(mod->name, &stat->name[0], namelen)) != 0) 353 goto out; 354 355 if ((error = copyout(&mod->refs, &stat->refs, sizeof(int))) != 0) 356 goto out; 357 if ((error = copyout(&mod->id, &stat->id, sizeof(int))) != 0) 358 goto out; 359 360 /* 361 * >v1 stat includes module data. 362 */ 363 if (version == sizeof(struct module_stat)) { 364 if ((error = copyout(&mod->data, &stat->data, sizeof(mod->data))) != 0) 365 goto out; 366 } 367 368 uap->sysmsg_result = 0; 369 370 out: 371 rel_mplock(); 372 return error; 373 } 374 375 /* 376 * MPALMOSTSAFE 377 */ 378 int 379 sys_modfind(struct modfind_args *uap) 380 { 381 int error; 382 char name[MAXMODNAME]; 383 module_t mod; 384 385 get_mplock(); 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 uap->sysmsg_result = mod->id; 394 395 out: 396 rel_mplock(); 397 return error; 398 } 399