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 #include <sys/mplock2.h> 42 43 MALLOC_DEFINE(M_MODULE, "module", "module data structures"); 44 45 typedef TAILQ_HEAD(, module) modulelist_t; 46 struct module { 47 TAILQ_ENTRY(module) link; /* chain together all modules */ 48 TAILQ_ENTRY(module) flink; /* all modules in a file */ 49 struct linker_file* file; /* file which contains this module */ 50 int refs; /* reference count */ 51 int id; /* unique id number */ 52 char *name; /* module name */ 53 modeventhand_t handler; /* event handler */ 54 void *arg; /* argument for handler */ 55 modspecific_t data; /* module specific data */ 56 }; 57 58 #define MOD_EVENT(mod, type) (mod)->handler((mod), (type), (mod)->arg) 59 60 static modulelist_t modules = TAILQ_HEAD_INITIALIZER(modules); 61 static int nextid = 1; 62 63 static void module_shutdown(void*, int); 64 65 static int 66 modevent_nop(module_t mod, int what, void* arg) 67 { 68 return 0; 69 } 70 71 72 static void 73 module_init(void* arg) 74 { 75 TAILQ_INIT(&modules); 76 EVENTHANDLER_REGISTER(shutdown_post_sync, module_shutdown, NULL, 77 SHUTDOWN_PRI_DEFAULT); 78 } 79 80 SYSINIT(module, SI_BOOT2_KLD, SI_ORDER_FIRST, module_init, 0); 81 82 static void 83 module_shutdown(void* arg1, int arg2) 84 { 85 module_t mod; 86 87 for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link)) 88 MOD_EVENT(mod, MOD_SHUTDOWN); 89 } 90 91 void 92 module_register_init(const void *arg) 93 { 94 const moduledata_t* data = (const moduledata_t*) arg; 95 int error; 96 module_t mod; 97 98 mod = module_lookupbyname(data->name); 99 if (mod == NULL) { 100 #if 0 101 panic("module_register_init: module named %s not found", data->name); 102 #else 103 /* temporary kludge until kernel `file' attachment registers modules */ 104 error = module_register(data, linker_kernel_file); 105 if (error) 106 panic("module_register_init: register of module failed! %d", error); 107 mod = module_lookupbyname(data->name); 108 if (mod == NULL) 109 panic("module_register_init: module STILL not found!"); 110 #endif 111 } 112 error = MOD_EVENT(mod, MOD_LOAD); 113 if (error) { 114 module_unload(mod); /* ignore error */ 115 module_release(mod); 116 kprintf("module_register_init: MOD_LOAD (%s, %lx, %p) error %d\n", 117 data->name, (u_long)(uintfptr_t)data->evhand, data->priv, error); 118 } 119 } 120 121 int 122 module_register(const moduledata_t *data, linker_file_t container) 123 { 124 size_t namelen; 125 module_t newmod; 126 127 newmod = module_lookupbyname(data->name); 128 if (newmod != NULL) { 129 kprintf("module_register: module %s already exists!\n", data->name); 130 return EEXIST; 131 } 132 namelen = strlen(data->name) + 1; 133 newmod = (module_t) kmalloc(sizeof(struct module) + namelen, 134 M_MODULE, M_WAITOK); 135 136 newmod->refs = 1; 137 newmod->id = nextid++; 138 newmod->name = (char *) (newmod + 1); 139 strcpy(newmod->name, data->name); 140 newmod->handler = data->evhand ? data->evhand : modevent_nop; 141 newmod->arg = data->priv; 142 bzero(&newmod->data, sizeof(newmod->data)); 143 TAILQ_INSERT_TAIL(&modules, newmod, link); 144 145 if (container == NULL) 146 container = linker_current_file; 147 if (container) 148 TAILQ_INSERT_TAIL(&container->modules, newmod, flink); 149 newmod->file = container; 150 151 return 0; 152 } 153 154 void 155 module_reference(module_t mod) 156 { 157 MOD_DPF(REFS, ("module_reference: before, refs=%d\n", mod->refs)); 158 159 mod->refs++; 160 } 161 162 /* 163 * module_release() 164 * 165 * Release ref on the module and return the new reference count. If 0 166 * is returned, the module has been removed from its list and freed. 167 */ 168 int 169 module_release(module_t mod) 170 { 171 int rc; 172 173 if (mod->refs <= 0) 174 panic("module_release: bad reference count"); 175 176 MOD_DPF(REFS, ("module_release: before, refs=%d\n", mod->refs)); 177 178 rc = --mod->refs; 179 if (rc == 0) { 180 TAILQ_REMOVE(&modules, mod, link); 181 if (mod->file) { 182 TAILQ_REMOVE(&mod->file->modules, mod, flink); 183 } 184 kfree(mod, M_MODULE); 185 } 186 return(rc); 187 } 188 189 module_t 190 module_lookupbyname(const char* name) 191 { 192 module_t mod; 193 194 for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link)) { 195 if (!strcmp(mod->name, name)) 196 return mod; 197 } 198 199 return NULL; 200 } 201 202 module_t 203 module_lookupbyid(int modid) 204 { 205 module_t mod; 206 207 for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link)) { 208 if (mod->id == modid) 209 return mod; 210 } 211 212 return NULL; 213 } 214 215 int 216 module_unload(module_t mod) 217 { 218 int error; 219 220 error = MOD_EVENT(mod, MOD_UNLOAD); 221 /*sync_devs();*/ 222 return (error); 223 } 224 225 int 226 module_getid(module_t mod) 227 { 228 return mod->id; 229 } 230 231 module_t 232 module_getfnext(module_t mod) 233 { 234 return TAILQ_NEXT(mod, flink); 235 } 236 237 void 238 module_setspecific(module_t mod, modspecific_t *datap) 239 { 240 mod->data = *datap; 241 } 242 243 /* 244 * Syscalls. 245 * 246 * MPALMOSTSAFE 247 */ 248 int 249 sys_modnext(struct modnext_args *uap) 250 { 251 module_t mod; 252 int error; 253 254 get_mplock(); 255 uap->sysmsg_result = -1; 256 if (uap->modid == 0) { 257 mod = TAILQ_FIRST(&modules); 258 if (mod) { 259 uap->sysmsg_result = mod->id; 260 error = 0; 261 goto done; 262 } else { 263 error = ENOENT; 264 goto done; 265 } 266 } 267 268 mod = module_lookupbyid(uap->modid); 269 if (!mod) { 270 error = ENOENT; 271 goto done; 272 } 273 274 if (TAILQ_NEXT(mod, link)) 275 uap->sysmsg_result = TAILQ_NEXT(mod, link)->id; 276 else 277 uap->sysmsg_result = 0; 278 error = 0; 279 done: 280 rel_mplock(); 281 return error; 282 } 283 284 /* 285 * MPALMOSTSAFE 286 */ 287 int 288 sys_modfnext(struct modfnext_args *uap) 289 { 290 module_t mod; 291 int error; 292 293 get_mplock(); 294 uap->sysmsg_result = -1; 295 296 mod = module_lookupbyid(uap->modid); 297 if (!mod) { 298 error = ENOENT; 299 goto done; 300 } 301 302 if (TAILQ_NEXT(mod, flink)) 303 uap->sysmsg_result = TAILQ_NEXT(mod, flink)->id; 304 else 305 uap->sysmsg_result = 0; 306 error = 0; 307 done: 308 rel_mplock(); 309 return error; 310 } 311 312 struct module_stat_v1 { 313 int version; /* set to sizeof(struct module_stat) */ 314 char name[MAXMODNAME]; 315 int refs; 316 int id; 317 }; 318 319 /* 320 * MPALMOSTSAFE 321 */ 322 int 323 sys_modstat(struct modstat_args *uap) 324 { 325 module_t mod; 326 int error; 327 int namelen; 328 int version; 329 struct module_stat* stat; 330 331 get_mplock(); 332 mod = module_lookupbyid(uap->modid); 333 if (!mod) { 334 error = ENOENT; 335 goto out; 336 } 337 338 stat = uap->stat; 339 340 /* 341 * Check the version of the user's structure. 342 */ 343 if ((error = copyin(&stat->version, &version, sizeof(version))) != 0) 344 goto out; 345 if (version != sizeof(struct module_stat_v1) 346 && version != sizeof(struct module_stat)) { 347 error = EINVAL; 348 goto out; 349 } 350 351 namelen = strlen(mod->name) + 1; 352 if (namelen > MAXMODNAME) 353 namelen = MAXMODNAME; 354 if ((error = copyout(mod->name, &stat->name[0], namelen)) != 0) 355 goto out; 356 357 if ((error = copyout(&mod->refs, &stat->refs, sizeof(int))) != 0) 358 goto out; 359 if ((error = copyout(&mod->id, &stat->id, sizeof(int))) != 0) 360 goto out; 361 362 /* 363 * >v1 stat includes module data. 364 */ 365 if (version == sizeof(struct module_stat)) { 366 if ((error = copyout(&mod->data, &stat->data, sizeof(mod->data))) != 0) 367 goto out; 368 } 369 370 uap->sysmsg_result = 0; 371 372 out: 373 rel_mplock(); 374 return error; 375 } 376 377 /* 378 * MPALMOSTSAFE 379 */ 380 int 381 sys_modfind(struct modfind_args *uap) 382 { 383 int error; 384 char name[MAXMODNAME]; 385 module_t mod; 386 387 get_mplock(); 388 if ((error = copyinstr(uap->name, name, sizeof name, 0)) != 0) 389 goto out; 390 391 mod = module_lookupbyname(name); 392 if (!mod) 393 error = ENOENT; 394 else 395 uap->sysmsg_result = mod->id; 396 397 out: 398 rel_mplock(); 399 return error; 400 } 401