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 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 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", 100 data->name); 101 error = MOD_EVENT(mod, MOD_LOAD); 102 if (error) { 103 MOD_EVENT(mod, MOD_UNLOAD); 104 module_release(mod); 105 printf("module_register_init: MOD_LOAD (%s, %p, %p) error" 106 " %d\n", data->name, (void *)data->evhand, data->priv, 107 error); 108 } 109 } 110 111 int 112 module_register(const moduledata_t *data, linker_file_t container) 113 { 114 size_t namelen; 115 module_t newmod; 116 117 newmod = module_lookupbyname(data->name); 118 if (newmod != NULL) { 119 printf("module_register: module %s already exists!\n", 120 data->name); 121 return (EEXIST); 122 } 123 namelen = strlen(data->name) + 1; 124 newmod = malloc(sizeof(struct module) + namelen, M_MODULE, M_WAITOK); 125 if (newmod == NULL) 126 return (ENOMEM); 127 newmod->refs = 1; 128 newmod->id = nextid++; 129 newmod->name = (char *)(newmod + 1); 130 strcpy(newmod->name, data->name); 131 newmod->handler = data->evhand ? data->evhand : modevent_nop; 132 newmod->arg = data->priv; 133 bzero(&newmod->data, sizeof(newmod->data)); 134 TAILQ_INSERT_TAIL(&modules, newmod, link); 135 136 if (container) 137 TAILQ_INSERT_TAIL(&container->modules, newmod, flink); 138 newmod->file = container; 139 return (0); 140 } 141 142 void 143 module_reference(module_t mod) 144 { 145 146 MOD_DPF(REFS, ("module_reference: before, refs=%d\n", mod->refs)); 147 mod->refs++; 148 } 149 150 void 151 module_release(module_t mod) 152 { 153 154 if (mod->refs <= 0) 155 panic("module_release: bad reference count"); 156 157 MOD_DPF(REFS, ("module_release: before, refs=%d\n", mod->refs)); 158 159 mod->refs--; 160 if (mod->refs == 0) { 161 TAILQ_REMOVE(&modules, mod, link); 162 if (mod->file) 163 TAILQ_REMOVE(&mod->file->modules, mod, flink); 164 free(mod, M_MODULE); 165 } 166 } 167 168 module_t 169 module_lookupbyname(const char *name) 170 { 171 module_t mod; 172 int err; 173 174 TAILQ_FOREACH(mod, &modules, link) { 175 err = strcmp(mod->name, name); 176 if (err == 0) 177 return (mod); 178 } 179 return (NULL); 180 } 181 182 module_t 183 module_lookupbyid(int modid) 184 { 185 module_t mod; 186 187 TAILQ_FOREACH(mod, &modules, link) { 188 if (mod->id == modid) 189 return (mod); 190 } 191 return (NULL); 192 } 193 194 int 195 module_unload(module_t mod) 196 { 197 198 return (MOD_EVENT(mod, MOD_UNLOAD)); 199 } 200 201 int 202 module_getid(module_t mod) 203 { 204 205 return (mod->id); 206 } 207 208 module_t 209 module_getfnext(module_t mod) 210 { 211 212 return (TAILQ_NEXT(mod, flink)); 213 } 214 215 void 216 module_setspecific(module_t mod, modspecific_t *datap) 217 { 218 219 mod->data = *datap; 220 } 221 222 /* 223 * Syscalls. 224 */ 225 /* 226 * MPSAFE 227 */ 228 int 229 modnext(struct thread *td, struct modnext_args *uap) 230 { 231 module_t mod; 232 int error = 0; 233 234 mtx_lock(&Giant); 235 236 td->td_retval[0] = -1; 237 if (SCARG(uap, modid) == 0) { 238 mod = TAILQ_FIRST(&modules); 239 if (mod) 240 td->td_retval[0] = mod->id; 241 else 242 error = ENOENT; 243 goto done2; 244 } 245 mod = module_lookupbyid(SCARG(uap, modid)); 246 if (mod == NULL) { 247 error = ENOENT; 248 goto done2; 249 } 250 if (TAILQ_NEXT(mod, link)) 251 td->td_retval[0] = TAILQ_NEXT(mod, link)->id; 252 else 253 td->td_retval[0] = 0; 254 done2: 255 mtx_unlock(&Giant); 256 return (error); 257 } 258 259 /* 260 * MPSAFE 261 */ 262 int 263 modfnext(struct thread *td, struct modfnext_args *uap) 264 { 265 module_t mod; 266 int error; 267 268 td->td_retval[0] = -1; 269 270 mtx_lock(&Giant); 271 272 mod = module_lookupbyid(SCARG(uap, modid)); 273 if (mod == NULL) { 274 error = ENOENT; 275 } else { 276 error = 0; 277 if (TAILQ_NEXT(mod, flink)) 278 td->td_retval[0] = TAILQ_NEXT(mod, flink)->id; 279 else 280 td->td_retval[0] = 0; 281 } 282 mtx_unlock(&Giant); 283 return (error); 284 } 285 286 struct module_stat_v1 { 287 int version; /* set to sizeof(struct module_stat) */ 288 char name[MAXMODNAME]; 289 int refs; 290 int id; 291 }; 292 293 /* 294 * MPSAFE 295 */ 296 int 297 modstat(struct thread *td, struct modstat_args *uap) 298 { 299 module_t mod; 300 int error = 0; 301 int namelen; 302 int version; 303 struct module_stat *stat; 304 305 mtx_lock(&Giant); 306 307 mod = module_lookupbyid(SCARG(uap, modid)); 308 if (mod == NULL) { 309 error = ENOENT; 310 goto out; 311 } 312 stat = SCARG(uap, stat); 313 314 /* 315 * Check the version of the user's structure. 316 */ 317 if ((error = copyin(&stat->version, &version, sizeof(version))) != 0) 318 goto out; 319 if (version != sizeof(struct module_stat_v1) 320 && version != sizeof(struct module_stat)) { 321 error = EINVAL; 322 goto out; 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, 340 sizeof(mod->data))) != 0) 341 goto out; 342 } 343 td->td_retval[0] = 0; 344 out: 345 mtx_unlock(&Giant); 346 return (error); 347 } 348 349 /* 350 * MPSAFE 351 */ 352 int 353 modfind(struct thread *td, struct modfind_args *uap) 354 { 355 int error = 0; 356 char name[MAXMODNAME]; 357 module_t mod; 358 359 if ((error = copyinstr(SCARG(uap, name), name, sizeof name, 0)) != 0) 360 goto out; 361 362 mtx_lock(&Giant); 363 mod = module_lookupbyname(name); 364 if (mod == NULL) 365 error = ENOENT; 366 else 367 td->td_retval[0] = mod->id; 368 mtx_unlock(&Giant); 369 out: 370 return (error); 371 } 372