sys/kern/kern_module.c

   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 }