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; 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 MOD_EVENT(mod, MOD_UNLOAD); 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 return MOD_EVENT(mod, MOD_UNLOAD); 217 } 218 219 int 220 module_getid(module_t mod) 221 { 222 return mod->id; 223 } 224 225 module_t 226 module_getfnext(module_t mod) 227 { 228 return TAILQ_NEXT(mod, flink); 229 } 230 231 void 232 module_setspecific(module_t mod, modspecific_t *datap) 233 { 234 mod->data = *datap; 235 } 236 237 /* 238 * Syscalls. 239 */ 240 int 241 sys_modnext(struct modnext_args *uap) 242 { 243 module_t mod; 244 245 uap->sysmsg_result = -1; 246 if (uap->modid == 0) { 247 mod = TAILQ_FIRST(&modules); 248 if (mod) { 249 uap->sysmsg_result = mod->id; 250 return 0; 251 } else 252 return ENOENT; 253 } 254 255 mod = module_lookupbyid(uap->modid); 256 if (!mod) 257 return ENOENT; 258 259 if (TAILQ_NEXT(mod, link)) 260 uap->sysmsg_result = TAILQ_NEXT(mod, link)->id; 261 else 262 uap->sysmsg_result = 0; 263 return 0; 264 } 265 266 int 267 sys_modfnext(struct modfnext_args *uap) 268 { 269 module_t mod; 270 271 uap->sysmsg_result = -1; 272 273 mod = module_lookupbyid(uap->modid); 274 if (!mod) 275 return ENOENT; 276 277 if (TAILQ_NEXT(mod, flink)) 278 uap->sysmsg_result = TAILQ_NEXT(mod, flink)->id; 279 else 280 uap->sysmsg_result = 0; 281 return 0; 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 int 292 sys_modstat(struct modstat_args *uap) 293 { 294 module_t mod; 295 int error = 0; 296 int namelen; 297 int version; 298 struct module_stat* stat; 299 300 mod = module_lookupbyid(uap->modid); 301 if (!mod) 302 return ENOENT; 303 304 stat = uap->stat; 305 306 /* 307 * Check the version of the user's structure. 308 */ 309 if ((error = copyin(&stat->version, &version, sizeof(version))) != 0) 310 goto out; 311 if (version != sizeof(struct module_stat_v1) 312 && version != sizeof(struct module_stat)) { 313 error = EINVAL; 314 goto out; 315 } 316 317 namelen = strlen(mod->name) + 1; 318 if (namelen > MAXMODNAME) 319 namelen = MAXMODNAME; 320 if ((error = copyout(mod->name, &stat->name[0], namelen)) != 0) 321 goto out; 322 323 if ((error = copyout(&mod->refs, &stat->refs, sizeof(int))) != 0) 324 goto out; 325 if ((error = copyout(&mod->id, &stat->id, sizeof(int))) != 0) 326 goto out; 327 328 /* 329 * >v1 stat includes module data. 330 */ 331 if (version == sizeof(struct module_stat)) { 332 if ((error = copyout(&mod->data, &stat->data, sizeof(mod->data))) != 0) 333 goto out; 334 } 335 336 uap->sysmsg_result = 0; 337 338 out: 339 return error; 340 } 341 342 int 343 sys_modfind(struct modfind_args *uap) 344 { 345 int error = 0; 346 char name[MAXMODNAME]; 347 module_t mod; 348 349 if ((error = copyinstr(uap->name, name, sizeof name, 0)) != 0) 350 goto out; 351 352 mod = module_lookupbyname(name); 353 if (!mod) 354 error = ENOENT; 355 else 356 uap->sysmsg_result = mod->id; 357 358 out: 359 return error; 360 } 361