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 = TAILQ_HEAD_INITIALIZER(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         module_unload(mod);     /* ignore error */
 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     int error;
 217
 218     error = MOD_EVENT(mod, MOD_UNLOAD);
 219     /*sync_devs();*/
 220     return (error);
 221 }
 222
 223 int
 224 module_getid(module_t mod)
 225 {
 226     return mod->id;
 227 }
 228
 229 module_t
 230 module_getfnext(module_t mod)
 231 {
 232     return TAILQ_NEXT(mod, flink);
 233 }
 234
 235 void
 236 module_setspecific(module_t mod, modspecific_t *datap)
 237 {
 238     mod->data = *datap;
 239 }
 240
 241 /*
 242  * Syscalls.
 243  */
 244 int
 245 sys_modnext(struct modnext_args *uap)
 246 {
 247     module_t mod;
 248
 249     uap->sysmsg_result = -1;
 250     if (uap->modid == 0) {
 251         mod = TAILQ_FIRST(&modules);
 252         if (mod) {
 253             uap->sysmsg_result = mod->id;
 254             return 0;
 255         } else
 256             return ENOENT;
 257     }
 258
 259     mod = module_lookupbyid(uap->modid);
 260     if (!mod)
 261         return ENOENT;
 262
 263     if (TAILQ_NEXT(mod, link))
 264         uap->sysmsg_result = TAILQ_NEXT(mod, link)->id;
 265     else
 266         uap->sysmsg_result = 0;
 267     return 0;
 268 }
 269
 270 int
 271 sys_modfnext(struct modfnext_args *uap)
 272 {
 273     module_t mod;
 274
 275     uap->sysmsg_result = -1;
 276
 277     mod = module_lookupbyid(uap->modid);
 278     if (!mod)
 279         return ENOENT;
 280
 281     if (TAILQ_NEXT(mod, flink))
 282         uap->sysmsg_result = TAILQ_NEXT(mod, flink)->id;
 283     else
 284         uap->sysmsg_result = 0;
 285     return 0;
 286 }
 287
 288 struct module_stat_v1 {
 289     int         version;        /* set to sizeof(struct module_stat) */
 290     char        name[MAXMODNAME];
 291     int         refs;
 292     int         id;
 293 };
 294
 295 int
 296 sys_modstat(struct modstat_args *uap)
 297 {
 298     module_t mod;
 299     int error = 0;
 300     int namelen;
 301     int version;
 302     struct module_stat* stat;
 303
 304     mod = module_lookupbyid(uap->modid);
 305     if (!mod)
 306         return ENOENT;
 307
 308     stat = uap->stat;
 309
 310     /*
 311      * Check the version of the user's structure.
 312      */
 313     if ((error = copyin(&stat->version, &version, sizeof(version))) != 0)
 314         goto out;
 315     if (version != sizeof(struct module_stat_v1)
 316         && version != sizeof(struct module_stat)) {
 317         error = EINVAL;
 318         goto out;
 319     }
 320
 321     namelen = strlen(mod->name) + 1;
 322     if (namelen > MAXMODNAME)
 323         namelen = MAXMODNAME;
 324     if ((error = copyout(mod->name, &stat->name[0], namelen)) != 0)
 325         goto out;
 326
 327     if ((error = copyout(&mod->refs, &stat->refs, sizeof(int))) != 0)
 328         goto out;
 329     if ((error = copyout(&mod->id, &stat->id, sizeof(int))) != 0)
 330         goto out;
 331
 332     /*
 333      * >v1 stat includes module data.
 334      */
 335     if (version == sizeof(struct module_stat)) {
 336         if ((error = copyout(&mod->data, &stat->data, sizeof(mod->data))) != 0)
 337             goto out;
 338     }
 339
 340     uap->sysmsg_result = 0;
 341
 342 out:
 343     return error;
 344 }
 345
 346 int
 347 sys_modfind(struct modfind_args *uap)
 348 {
 349     int error = 0;
 350     char name[MAXMODNAME];
 351     module_t mod;
 352
 353     if ((error = copyinstr(uap->name, name, sizeof name, 0)) != 0)
 354         goto out;
 355
 356     mod = module_lookupbyname(name);
 357     if (!mod)
 358         error = ENOENT;
 359     else
 360         uap->sysmsg_result = mod->id;
 361
 362 out:
 363     return error;
 364 }