kern_module.c revision 90963
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: head/sys/kern/kern_module.c 90963 2002-02-20 14:30:02Z arr $ 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 42static MALLOC_DEFINE(M_MODULE, "module", "module data structures"); 43 44typedef TAILQ_HEAD(, module) modulelist_t; 45struct 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 59static modulelist_t modules; 60static int nextid = 1; 61static void module_shutdown(void *, int); 62 63static int 64modevent_nop(module_t mod, int what, void *arg) 65{ 66 return 0; 67} 68 69 70static void 71module_init(void *arg) 72{ 73 74 TAILQ_INIT(&modules); 75 EVENTHANDLER_REGISTER(shutdown_post_sync, module_shutdown, NULL, 76 SHUTDOWN_PRI_DEFAULT); 77} 78 79SYSINIT(module, SI_SUB_KLD, SI_ORDER_FIRST, module_init, 0) 80 81static void 82module_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 90void 91module_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( 106 "module_register_init: MOD_LOAD (%s, %lx, %p) error %d\n", 107 data->name, (u_long)(uintfptr_t)data->evhand, data->priv, 108 error); 109 } 110} 111 112int 113module_register(const moduledata_t *data, linker_file_t container) 114{ 115 size_t namelen; 116 module_t newmod; 117 118 newmod = module_lookupbyname(data->name); 119 if (newmod != NULL) { 120 printf("module_register: module %s already exists!\n", 121 data->name); 122 return EEXIST; 123 } 124 namelen = strlen(data->name) + 1; 125 newmod = malloc(sizeof(struct module) + namelen, M_MODULE, M_WAITOK); 126 if (newmod == NULL) 127 return ENOMEM; 128 newmod->refs = 1; 129 newmod->id = nextid++; 130 newmod->name = (char *)(newmod + 1); 131 strcpy(newmod->name, data->name); 132 newmod->handler = data->evhand ? data->evhand : modevent_nop; 133 newmod->arg = data->priv; 134 bzero(&newmod->data, sizeof(newmod->data)); 135 TAILQ_INSERT_TAIL(&modules, newmod, link); 136 137 if (container) 138 TAILQ_INSERT_TAIL(&container->modules, newmod, flink); 139 newmod->file = container; 140 return 0; 141} 142 143void 144module_reference(module_t mod) 145{ 146 147 MOD_DPF(REFS, ("module_reference: before, refs=%d\n", mod->refs)); 148 mod->refs++; 149} 150 151void 152module_release(module_t mod) 153{ 154 155 if (mod->refs <= 0) 156 panic("module_release: bad reference count"); 157 158 MOD_DPF(REFS, ("module_release: before, refs=%d\n", mod->refs)); 159 160 mod->refs--; 161 if (mod->refs == 0) { 162 TAILQ_REMOVE(&modules, mod, link); 163 if (mod->file) 164 TAILQ_REMOVE(&mod->file->modules, mod, flink); 165 free(mod, M_MODULE); 166 } 167} 168 169module_t 170module_lookupbyname(const char *name) 171{ 172 module_t mod; 173 int err; 174 175 TAILQ_FOREACH(mod, &modules, link) { 176 err = strcmp(mod->name, name); 177 if (err == 0) 178 return mod; 179 } 180 return 0; 181} 182 183module_t 184module_lookupbyid(int modid) 185{ 186 module_t mod; 187 188 TAILQ_FOREACH(mod, &modules, link) { 189 if (mod->id == modid) 190 return mod; 191 } 192 return 0; 193} 194 195int 196module_unload(module_t mod) 197{ 198 199 return MOD_EVENT(mod, MOD_UNLOAD); 200} 201 202int 203module_getid(module_t mod) 204{ 205 206 return mod->id; 207} 208 209module_t 210module_getfnext(module_t mod) 211{ 212 213 return TAILQ_NEXT(mod, flink); 214} 215 216void 217module_setspecific(module_t mod, modspecific_t *datap) 218{ 219 220 mod->data = *datap; 221} 222 223/* 224 * Syscalls. 225 */ 226/* 227 * MPSAFE 228 */ 229int 230modnext(struct thread *td, struct modnext_args *uap) 231{ 232 module_t mod; 233 int error = 0; 234 235 mtx_lock(&Giant); 236 237 td->td_retval[0] = -1; 238 if (SCARG(uap, modid) == 0) { 239 mod = TAILQ_FIRST(&modules); 240 if (mod) 241 td->td_retval[0] = mod->id; 242 else 243 error = ENOENT; 244 goto done2; 245 } 246 mod = module_lookupbyid(SCARG(uap, modid)); 247 if (mod == NULL) { 248 error = ENOENT; 249 goto done2; 250 } 251 if (TAILQ_NEXT(mod, link)) 252 td->td_retval[0] = TAILQ_NEXT(mod, link)->id; 253 else 254 td->td_retval[0] = 0; 255done2: 256 mtx_unlock(&Giant); 257 return (error); 258} 259 260/* 261 * MPSAFE 262 */ 263int 264modfnext(struct thread *td, struct modfnext_args *uap) 265{ 266 module_t mod; 267 int error; 268 269 td->td_retval[0] = -1; 270 271 mtx_lock(&Giant); 272 273 mod = module_lookupbyid(SCARG(uap, modid)); 274 if (mod == NULL) { 275 error = ENOENT; 276 } else { 277 error = 0; 278 if (TAILQ_NEXT(mod, flink)) 279 td->td_retval[0] = TAILQ_NEXT(mod, flink)->id; 280 else 281 td->td_retval[0] = 0; 282 } 283 mtx_unlock(&Giant); 284 return (error); 285} 286 287struct module_stat_v1 { 288 int version; /* set to sizeof(struct module_stat) */ 289 char name[MAXMODNAME]; 290 int refs; 291 int id; 292}; 293 294/* 295 * MPSAFE 296 */ 297int 298modstat(struct thread *td, struct modstat_args *uap) 299{ 300 module_t mod; 301 int error = 0; 302 int namelen; 303 int version; 304 struct module_stat *stat; 305 306 mtx_lock(&Giant); 307 308 mod = module_lookupbyid(SCARG(uap, modid)); 309 if (mod == NULL) { 310 error = ENOENT; 311 goto out; 312 } 313 stat = SCARG(uap, stat); 314 315 /* 316 * Check the version of the user's structure. 317 */ 318 if ((error = copyin(&stat->version, &version, sizeof(version))) != 0) 319 goto out; 320 if (version != sizeof(struct module_stat_v1) 321 && version != sizeof(struct module_stat)) { 322 error = EINVAL; 323 goto out; 324 } 325 namelen = strlen(mod->name) + 1; 326 if (namelen > MAXMODNAME) 327 namelen = MAXMODNAME; 328 if ((error = copyout(mod->name, &stat->name[0], namelen)) != 0) 329 goto out; 330 331 if ((error = copyout(&mod->refs, &stat->refs, sizeof(int))) != 0) 332 goto out; 333 if ((error = copyout(&mod->id, &stat->id, sizeof(int))) != 0) 334 goto out; 335 336 /* 337 * >v1 stat includes module data. 338 */ 339 if (version == sizeof(struct module_stat)) { 340 if ((error = copyout(&mod->data, &stat->data, 341 sizeof(mod->data))) != 0) 342 goto out; 343 } 344 td->td_retval[0] = 0; 345out: 346 mtx_unlock(&Giant); 347 return error; 348} 349 350/* 351 * MPSAFE 352 */ 353int 354modfind(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); 370out: 371 return error; 372} 373