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