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 1.8 2004/05/10 10:51:31 hmp 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_SUB_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 printf("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 printf("module_register: module %s already exists!\n", data->name); 128 return EEXIST; 129 } 130 namelen = strlen(data->name) + 1; 131 newmod = (module_t) malloc(sizeof(struct module) + namelen, 132 M_MODULE, M_WAITOK); 133 if (newmod == 0) 134 return ENOMEM; 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 free(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 0; 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 0; 213 } 214 215 int 216 module_unload(module_t mod) 217 { 218 return MOD_EVENT(mod, MOD_UNLOAD); 219 } 220 221 int 222 module_getid(module_t mod) 223 { 224 return mod->id; 225 } 226 227 module_t 228 module_getfnext(module_t mod) 229 { 230 return TAILQ_NEXT(mod, flink); 231 } 232 233 void 234 module_setspecific(module_t mod, modspecific_t *datap) 235 { 236 mod->data = *datap; 237 } 238 239 /* 240 * Syscalls. 241 */ 242 int 243 modnext(struct modnext_args *uap) 244 { 245 module_t mod; 246 247 uap->sysmsg_result = -1; 248 if (SCARG(uap, modid) == 0) { 249 mod = TAILQ_FIRST(&modules); 250 if (mod) { 251 uap->sysmsg_result = mod->id; 252 return 0; 253 } else 254 return ENOENT; 255 } 256 257 mod = module_lookupbyid(SCARG(uap, modid)); 258 if (!mod) 259 return ENOENT; 260 261 if (TAILQ_NEXT(mod, link)) 262 uap->sysmsg_result = TAILQ_NEXT(mod, link)->id; 263 else 264 uap->sysmsg_result = 0; 265 return 0; 266 } 267 268 int 269 modfnext(struct modfnext_args *uap) 270 { 271 module_t mod; 272 273 uap->sysmsg_result = -1; 274 275 mod = module_lookupbyid(SCARG(uap, modid)); 276 if (!mod) 277 return ENOENT; 278 279 if (TAILQ_NEXT(mod, flink)) 280 uap->sysmsg_result = TAILQ_NEXT(mod, flink)->id; 281 else 282 uap->sysmsg_result = 0; 283 return 0; 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 int 294 modstat(struct modstat_args *uap) 295 { 296 module_t mod; 297 int error = 0; 298 int namelen; 299 int version; 300 struct module_stat* stat; 301 302 mod = module_lookupbyid(SCARG(uap, modid)); 303 if (!mod) 304 return ENOENT; 305 306 stat = SCARG(uap, stat); 307 308 /* 309 * Check the version of the user's structure. 310 */ 311 if ((error = copyin(&stat->version, &version, sizeof(version))) != 0) 312 goto out; 313 if (version != sizeof(struct module_stat_v1) 314 && version != sizeof(struct module_stat)) { 315 error = EINVAL; 316 goto out; 317 } 318 319 namelen = strlen(mod->name) + 1; 320 if (namelen > MAXMODNAME) 321 namelen = MAXMODNAME; 322 if ((error = copyout(mod->name, &stat->name[0], namelen)) != 0) 323 goto out; 324 325 if ((error = copyout(&mod->refs, &stat->refs, sizeof(int))) != 0) 326 goto out; 327 if ((error = copyout(&mod->id, &stat->id, sizeof(int))) != 0) 328 goto out; 329 330 /* 331 * >v1 stat includes module data. 332 */ 333 if (version == sizeof(struct module_stat)) { 334 if ((error = copyout(&mod->data, &stat->data, sizeof(mod->data))) != 0) 335 goto out; 336 } 337 338 uap->sysmsg_result = 0; 339 340 out: 341 return error; 342 } 343 344 int 345 modfind(struct modfind_args *uap) 346 { 347 int error = 0; 348 char name[MAXMODNAME]; 349 module_t mod; 350 351 if ((error = copyinstr(SCARG(uap, name), name, sizeof name, 0)) != 0) 352 goto out; 353 354 mod = module_lookupbyname(name); 355 if (!mod) 356 error = ENOENT; 357 else 358 uap->sysmsg_result = mod->id; 359 360 out: 361 return error; 362 } 363