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 1.9 2005/03/29 00:35:55 drhodus 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 (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(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(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(uap->modid);
 303     if (!mod)
 304         return ENOENT;
 305
 306     stat = 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(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 }