FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_module.c

     /*-
      * Copyright (c) 1997 Doug Rabson
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
      * 1. Redistributions of source code must retain the above copyright
      *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     * $FreeBSD$
     */
    
    #include <sys/param.h>
    #include <sys/kernel.h>
    #include <sys/systm.h>
    #include <sys/malloc.h>
    #include <sys/sysproto.h>
    #include <sys/sysent.h>
    #include <sys/module.h>
    #include <sys/linker.h>
    #include <sys/proc.h>
    
    #define M_MODULE        M_TEMP          /* XXX */
    
    typedef TAILQ_HEAD(, module) modulelist_t;
    struct module {
        TAILQ_ENTRY(module) link;           /* chain together all modules */
        TAILQ_ENTRY(module) flink;          /* all modules in a file */
        struct linker_file* file;           /* file which contains this module */
        int                 refs;           /* reference count */
        int                 id;             /* unique id number */
        char                *name;          /* module name */
        modeventhand_t      handler;        /* event handler */
        void                *arg;           /* argument for handler */
        modspecific_t       data;           /* module specific data */
    };
    
    #define MOD_EVENT(mod, type) (mod)->handler((mod), (type), (mod)->arg)
    
    static modulelist_t modules;
    static int nextid = 1;
    
    static void module_shutdown(int, void*);
    
    static void
    module_init(void* arg)
    {
        TAILQ_INIT(&modules);
        at_shutdown(module_shutdown, 0, SHUTDOWN_POST_SYNC);
    }
    
    SYSINIT(module, SI_SUB_KLD, SI_ORDER_FIRST, module_init, 0);
    
    static void
    module_shutdown(int arg1, void* arg2)
    {
        module_t mod;
    
        for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link))
            MOD_EVENT(mod, MOD_SHUTDOWN);
    }
    
    void
    module_register_init(void *arg)
    {
        moduledata_t* data = (moduledata_t*) arg;
        int error;
    
        error = module_register(data->name, data->evhand, data->priv, data->_file);
        if (error)
            printf("module_register_init: module_register(%s, %lx, %p) error %d\n",
                   data->name, (u_long)(uintfptr_t)data->evhand, data->priv, error);
    }
    
    int
    module_register(const char* name, modeventhand_t handler, void* arg, void *file)
    {
        size_t namelen;
        module_t newmod;
        int error;
        linker_file_t container = file;
    
        namelen = strlen(name) + 1;
       newmod = (module_t) malloc(sizeof(struct module) + namelen,
                                  M_MODULE, M_WAITOK);
       if (newmod == 0)
           return ENOMEM;
   
       newmod->refs = 1;
       newmod->id = nextid++;
       newmod->name = (char *) (newmod + 1);
       strcpy(newmod->name, name);
       newmod->handler = handler;
       newmod->arg = arg;
       bzero(&newmod->data, sizeof(newmod->data));
       TAILQ_INSERT_TAIL(&modules, newmod, link);
   
       if (container == NULL)
           container = linker_current_file;
       if (container) {
           TAILQ_INSERT_TAIL(&container->modules, newmod, flink);
           newmod->file = container;
       } else
           newmod->file = 0;
   
       if (error = MOD_EVENT(newmod, MOD_LOAD)) {
           MOD_EVENT(newmod, MOD_UNLOAD);
           module_release(newmod);
           return error;
       }
   
       return 0;
   }
   
   void
   module_reference(module_t mod)
   {
       MOD_DPF(REFS, ("module_reference: before, refs=%d\n", mod->refs));
   
       mod->refs++;
   }
   
   void
   module_release(module_t mod)
   {
       if (mod->refs <= 0)
           panic("module_release: bad reference count");
   
       MOD_DPF(REFS, ("module_release: before, refs=%d\n", mod->refs));
   
       mod->refs--;
       if (mod->refs == 0) {
           TAILQ_REMOVE(&modules, mod, link);
           if (mod->file) {
               TAILQ_REMOVE(&mod->file->modules, mod, flink);
           }
           free(mod, M_MODULE);
       }
   }
   
   module_t
   module_lookupbyname(const char* name)
   {
       module_t mod;
   
       for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link)) {
           if (!strcmp(mod->name, name))
               return mod;
       }
   
       return 0;
   }
   
   module_t
   module_lookupbyid(int modid)
   {
       module_t mod;
   
       for (mod = TAILQ_FIRST(&modules); mod; mod = TAILQ_NEXT(mod, link)) {
           if (mod->id == modid)
               return mod;
       }
   
       return 0;
   }
   
   int
   module_unload(module_t mod)
   {
       return MOD_EVENT(mod, MOD_UNLOAD);
   }
   
   int
   module_getid(module_t mod)
   {
       return mod->id;
   }
   
   module_t
   module_getfnext(module_t mod)
   {
       return TAILQ_NEXT(mod, flink);
   }
   
   void
   module_setspecific(module_t mod, modspecific_t *datap)
   {
       mod->data = *datap;
   }
   
   /*
    * Syscalls.
    */
   int
   modnext(struct proc* p, struct modnext_args* uap)
   {
       module_t mod;
   
       p->p_retval[0] = -1;
       if (SCARG(uap, modid) == 0) {
           mod = TAILQ_FIRST(&modules);
           if (mod) {
               p->p_retval[0] = mod->id;
               return 0;
           } else
               return ENOENT;
       }
   
       mod = module_lookupbyid(SCARG(uap, modid));
       if (!mod)
           return ENOENT;
   
       if (TAILQ_NEXT(mod, link))
           p->p_retval[0] = TAILQ_NEXT(mod, link)->id;
       else
           p->p_retval[0] = 0;
       return 0;
   }
   
   int
   modfnext(struct proc* p, struct modfnext_args* uap)
   {
       module_t mod;
   
       p->p_retval[0] = -1;
   
       mod = module_lookupbyid(SCARG(uap, modid));
       if (!mod)
           return ENOENT;
   
       if (TAILQ_NEXT(mod, flink))
           p->p_retval[0] = TAILQ_NEXT(mod, flink)->id;
       else
           p->p_retval[0] = 0;
       return 0;
   }
   
   struct module_stat_v1 {
       int         version;        /* set to sizeof(struct module_stat) */
       char        name[MAXMODNAME];
       int         refs;
       int         id;
   };
   
   int
   modstat(struct proc* p, struct modstat_args* uap)
   {
       module_t mod;
       int error = 0;
       int namelen;
       int version;
       struct module_stat* stat;
   
       mod = module_lookupbyid(SCARG(uap, modid));
       if (!mod)
           return ENOENT;
   
       stat = SCARG(uap, stat);
   
       /*
        * Check the version of the user's structure.
        */
       if (error = copyin(&stat->version, &version, sizeof(version)))
           goto out;
       if (version != sizeof(struct module_stat_v1)
           && version != sizeof(struct module_stat)) {
           error = EINVAL;
           goto out;
       }
   
       namelen = strlen(mod->name) + 1;
       if (namelen > MAXMODNAME)
           namelen = MAXMODNAME;
       if (error = copyout(mod->name, &stat->name[0], namelen))
           goto out;
   
       if (error = copyout(&mod->refs, &stat->refs, sizeof(int)))
           goto out;
       if (error = copyout(&mod->id, &stat->id, sizeof(int)))
           goto out;
   
       /*
        * >v1 stat includes module data.
        */
       if (version == sizeof(struct module_stat)) {
           if (error = copyout(&mod->data, &stat->data, sizeof(mod->data)))
               goto out;
       }
   
       p->p_retval[0] = 0;
   
   out:
       return error;
   }
   
   int
   modfind(struct proc* p, struct modfind_args* uap)
   {
       int error = 0;
       char name[MAXMODNAME];
       module_t mod;
   
       if (error = copyinstr(SCARG(uap, name), name, sizeof name, 0))
           goto out;
   
       mod = module_lookupbyname(name);
       if (!mod)
           error = ENOENT;
       else
           p->p_retval[0] = mod->id;
   
   out:
       return error;
   }

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