#include <linux/config.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <asm/module.h>
#include <asm/uaccess.h>
#include <linux/vmalloc.h>
#include <linux/smp_lock.h>
#include <asm/pgalloc.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/kmod.h>
#include <linux/seq_file.h>

/*
 * Originally by Anonymous (as far as I know...)
 * Linux version by Bas Laarhoven <bas@vimec.nl>
 * 0.99.14 version by Jon Tombs <jon@gtex02.us.es>,
 * Heavily modified by Bjorn Ekwall <bj0rn@blox.se> May 1994 (C)
 * Rewritten by Richard Henderson <rth@tamu.edu> Dec 1996
 * Add MOD_INITIALIZING Keith Owens <kaos@ocs.com.au> Nov 1999
 * Add kallsyms support, Keith Owens <kaos@ocs.com.au> Apr 2000
 * Add asm/module support, IA64 has special requirements.  Keith Owens <kaos@ocs.com.au> Sep 2000
 * Fix assorted bugs in module verification.  Keith Owens <kaos@ocs.com.au> Sep 2000
 * Fix sys_init_module race, Andrew Morton <andrewm@uow.edu.au> Oct 2000
 *     http://www.uwsg.iu.edu/hypermail/linux/kernel/0008.3/0379.html
 * Replace xxx_module_symbol with inter_module_xxx.  Keith Owens <kaos@ocs.com.au> Oct 2000
 * Add a module list lock for kernel fault race fixing. Alan Cox <alan@redhat.com>
 *
 * This source is covered by the GNU GPL, the same as all kernel sources.
 */

#if defined(CONFIG_MODULES) || defined(CONFIG_KALLSYMS)

extern struct module_symbol __start___ksymtab[];
extern struct module_symbol __stop___ksymtab[];

extern const struct exception_table_entry __start___ex_table[];
extern const struct exception_table_entry __stop___ex_table[];

extern const char __start___kallsyms[] __attribute__ ((weak));
extern const char __stop___kallsyms[] __attribute__ ((weak));

struct module kernel_module =
{
        size_of_struct:         sizeof(struct module),
        name:                   "",
        uc:                     {ATOMIC_INIT(1)},
        flags:                  MOD_RUNNING,
        syms:                   __start___ksymtab,
        ex_table_start:         __start___ex_table,
        ex_table_end:           __stop___ex_table,
        kallsyms_start:         __start___kallsyms,
        kallsyms_end:           __stop___kallsyms,
};

struct module *module_list = &kernel_module;

#endif  /* defined(CONFIG_MODULES) || defined(CONFIG_KALLSYMS) */

/* inter_module functions are always available, even when the kernel is
 * compiled without modules.  Consumers of inter_module_xxx routines
 * will always work, even when both are built into the kernel, this
 * approach removes lots of #ifdefs in mainline code.
 */

static struct list_head ime_list = LIST_HEAD_INIT(ime_list);
static spinlock_t ime_lock = SPIN_LOCK_UNLOCKED;
static int kmalloc_failed;

/*
 *      This lock prevents modifications that might race the kernel fault
 *      fixups. It does not prevent reader walks that the modules code
 *      does. The kernel lock does that.
 *
 *      Since vmalloc fault fixups occur in any context this lock is taken
 *      irqsave at all times.
 */
 
spinlock_t modlist_lock = SPIN_LOCK_UNLOCKED;

/**
 * inter_module_register - register a new set of inter module data.
 * @im_name: an arbitrary string to identify the data, must be unique
 * @owner: module that is registering the data, always use THIS_MODULE
 * @userdata: pointer to arbitrary userdata to be registered
 *
 * Description: Check that the im_name has not already been registered,
 * complain if it has.  For new data, add it to the inter_module_entry
 * list.
 */
void inter_module_register(const char *im_name, struct module *owner, const void *userdata)
{
        struct list_head *tmp;
        struct inter_module_entry *ime, *ime_new;

        if (!(ime_new = kmalloc(sizeof(*ime), GFP_KERNEL))) {
                /* Overloaded kernel, not fatal */
                printk(KERN_ERR
                        "Aiee, inter_module_register: cannot kmalloc entry for '%s'\n",
                        im_name);
                kmalloc_failed = 1;
                return;
        }
        memset(ime_new, 0, sizeof(*ime_new));
        ime_new->im_name = im_name;
        ime_new->owner = owner;
        ime_new->userdata = userdata;

        spin_lock(&ime_lock);
        list_for_each(tmp, &ime_list) {
                ime = list_entry(tmp, struct inter_module_entry, list);
                if (strcmp(ime->im_name, im_name) == 0) {
                        spin_unlock(&ime_lock);
                        kfree(ime_new);
                        /* Program logic error, fatal */
                        printk(KERN_ERR "inter_module_register: duplicate im_name '%s'", im_name);
                        BUG();
                }
        }
        list_add(&(ime_new->list), &ime_list);
        spin_unlock(&ime_lock);
}

/**
 * inter_module_unregister - unregister a set of inter module data.
 * @im_name: an arbitrary string to identify the data, must be unique
 *
 * Description: Check that the im_name has been registered, complain if
 * it has not.  For existing data, remove it from the
 * inter_module_entry list.
 */
void inter_module_unregister(const char *im_name)
{
        struct list_head *tmp;
        struct inter_module_entry *ime;

        spin_lock(&ime_lock);
        list_for_each(tmp, &ime_list) {
                ime = list_entry(tmp, struct inter_module_entry, list);
                if (strcmp(ime->im_name, im_name) == 0) {
                        list_del(&(ime->list));
                        spin_unlock(&ime_lock);
                        kfree(ime);
                        return;
                }
        }
        spin_unlock(&ime_lock);
        if (kmalloc_failed) {
                printk(KERN_ERR
                        "inter_module_unregister: no entry for '%s', "
                        "probably caused by previous kmalloc failure\n",
                        im_name);
                return;
        }
        else {
                /* Program logic error, fatal */
                printk(KERN_ERR "inter_module_unregister: no entry for '%s'", im_name);
                BUG();
        }
}

/**
 * inter_module_get - return arbitrary userdata from another module.
 * @im_name: an arbitrary string to identify the data, must be unique
 *
 * Description: If the im_name has not been registered, return NULL.
 * Try to increment the use count on the owning module, if that fails
 * then return NULL.  Otherwise return the userdata.
 */
const void *inter_module_get(const char *im_name)
{
        struct list_head *tmp;
        struct inter_module_entry *ime;
        const void *result = NULL;

        spin_lock(&ime_lock);
        list_for_each(tmp, &ime_list) {
                ime = list_entry(tmp, struct inter_module_entry, list);
                if (strcmp(ime->im_name, im_name) == 0) {
                        if (try_inc_mod_count(ime->owner))
                                result = ime->userdata;
                        break;
                }
        }
        spin_unlock(&ime_lock);
        return(result);
}

/**
 * inter_module_get_request - im get with automatic request_module.
 * @im_name: an arbitrary string to identify the data, must be unique
 * @modname: module that is expected to register im_name
 *
 * Description: If inter_module_get fails, do request_module then retry.
 */
const void *inter_module_get_request(const char *im_name, const char *modname)
{
        const void *result = inter_module_get(im_name);
        if (!result) {
                request_module(modname);
                result = inter_module_get(im_name);
        }
        return(result);
}

/**
 * inter_module_put - release use of data from another module.
 * @im_name: an arbitrary string to identify the data, must be unique
 *
 * Description: If the im_name has not been registered, complain,
 * otherwise decrement the use count on the owning module.
 */
void inter_module_put(const char *im_name)
{
        struct list_head *tmp;
        struct inter_module_entry *ime;

        spin_lock(&ime_lock);
        list_for_each(tmp, &ime_list) {
                ime = list_entry(tmp, struct inter_module_entry, list);
                if (strcmp(ime->im_name, im_name) == 0) {
                        if (ime->owner)
                                __MOD_DEC_USE_COUNT(ime->owner);
                        spin_unlock(&ime_lock);
                        return;
                }
        }
        spin_unlock(&ime_lock);
        printk(KERN_ERR "inter_module_put: no entry for '%s'", im_name);
        BUG();
}


#if defined(CONFIG_MODULES)     /* The rest of the source */

static long get_mod_name(const char *user_name, char **buf);
static void put_mod_name(char *buf);
struct module *find_module(const char *name);
void free_module(struct module *, int tag_freed);


/*
 * Called at boot time
 */

void __init init_modules(void)
{
        kernel_module.nsyms = __stop___ksymtab - __start___ksymtab;

        arch_init_modules(&kernel_module);
}

/*
 * Copy the name of a module from user space.
 */

static inline long
get_mod_name(const char *user_name, char **buf)
{
        unsigned long page;
        long retval;

        page = __get_free_page(GFP_KERNEL);
        if (!page)
                return -ENOMEM;

        retval = strncpy_from_user((char *)page, user_name, PAGE_SIZE);
        if (retval > 0) {
                if (retval < PAGE_SIZE) {
                        *buf = (char *)page;
                        return retval;
                }
                retval = -ENAMETOOLONG;
        } else if (!retval)
                retval = -EINVAL;

        free_page(page);
        return retval;
}

static inline void
put_mod_name(char *buf)
{
        free_page((unsigned long)buf);
}

/*
 * Allocate space for a module.
 */

asmlinkage unsigned long
sys_create_module(const char *name_user, size_t size)
{
        char *name;
        long namelen, error;
        struct module *mod;
        unsigned long flags;

        if (!capable(CAP_SYS_MODULE))
                return -EPERM;
        lock_kernel();
        if ((namelen = get_mod_name(name_user, &name)) < 0) {
                error = namelen;
                goto err0;
        }
        if (size < sizeof(struct module)+namelen+1) {
                error = -EINVAL;
                goto err1;
        }
        if (find_module(name) != NULL) {
                error = -EEXIST;
                goto err1;
        }
        if ((mod = (struct module *)module_map(size)) == NULL) {
                error = -ENOMEM;
                goto err1;
        }

        memset(mod, 0, sizeof(*mod));
        mod->size_of_struct = sizeof(*mod);
        mod->name = (char *)(mod + 1);
        mod->size = size;
        memcpy((char*)(mod+1), name, namelen+1);

        put_mod_name(name);

        spin_lock_irqsave(&modlist_lock, flags);
        mod->next = module_list;
        module_list = mod;      /* link it in */
        spin_unlock_irqrestore(&modlist_lock, flags);

        error = (long) mod;
        goto err0;
err1:
        put_mod_name(name);
err0:
        unlock_kernel();
        return error;
}

/*
 * Initialize a module.
 */

asmlinkage long
sys_init_module(const char *name_user, struct module *mod_user)
{
        struct module mod_tmp, *mod, *mod2 = NULL;
        char *name, *n_name, *name_tmp = NULL;
        long namelen, n_namelen, i, error;
        unsigned long mod_user_size, flags;
        struct module_ref *dep;

        if (!capable(CAP_SYS_MODULE))
                return -EPERM;
        lock_kernel();
        if ((namelen = get_mod_name(name_user, &name)) < 0) {
                error = namelen;
                goto err0;
        }
        if ((mod = find_module(name)) == NULL) {
                error = -ENOENT;
                goto err1;
        }

        /* Check module header size.  We allow a bit of slop over the
           size we are familiar with to cope with a version of insmod
           for a newer kernel.  But don't over do it. */
        if ((error = get_user(mod_user_size, &mod_user->size_of_struct)) != 0)
                goto err1;
        if (mod_user_size < (unsigned long)&((struct module *)0L)->persist_start
            || mod_user_size > sizeof(struct module) + 16*sizeof(void*)) {
                printk(KERN_ERR "init_module: Invalid module header size.\n"
                       KERN_ERR "A new version of the modutils is likely "
                                "needed.\n");
                error = -EINVAL;
                goto err1;
        }

        /* Hold the current contents while we play with the user's idea
           of righteousness.  */
        mod_tmp = *mod;
        name_tmp = kmalloc(strlen(mod->name) + 1, GFP_KERNEL);  /* Where's kstrdup()? */
        if (name_tmp == NULL) {
                error = -ENOMEM;
                goto err1;
        }
        strcpy(name_tmp, mod->name);

        /* Copying mod_user directly over mod breaks the module_list chain and
         * races against search_exception_table.  copy_from_user may sleep so it
         * cannot be under modlist_lock, do the copy in two stages.
         */
        if (!(mod2 = vmalloc(mod_user_size))) {
                error = -ENOMEM;
                goto err2;
        }
        error = copy_from_user(mod2, mod_user, mod_user_size);
        if (error) {
                error = -EFAULT;
                goto err2;
        }
        spin_lock_irqsave(&modlist_lock, flags);
        memcpy(mod, mod2, mod_user_size);
        mod->next = mod_tmp.next;
        spin_unlock_irqrestore(&modlist_lock, flags);

        /* Sanity check the size of the module.  */
        error = -EINVAL;

        if (mod->size > mod_tmp.size) {
                printk(KERN_ERR "init_module: Size of initialized module "
                                "exceeds size of created module.\n");
                goto err2;
        }

        /* Make sure all interesting pointers are sane.  */

        if (!mod_bound(mod->name, namelen, mod)) {
                printk(KERN_ERR "init_module: mod->name out of bounds.\n");
                goto err2;
        }
        if (mod->nsyms && !mod_bound(mod->syms, mod->nsyms, mod)) {
                printk(KERN_ERR "init_module: mod->syms out of bounds.\n");
                goto err2;
        }
        if (mod->ndeps && !mod_bound(mod->deps, mod->ndeps, mod)) {
                printk(KERN_ERR "init_module: mod->deps out of bounds.\n");
                goto err2;
        }
        if (mod->init && !mod_bound(mod->init, 0, mod)) {
                printk(KERN_ERR "init_module: mod->init out of bounds.\n");
                goto err2;
        }
        if (mod->cleanup && !mod_bound(mod->cleanup, 0, mod)) {
                printk(KERN_ERR "init_module: mod->cleanup out of bounds.\n");
                goto err2;
        }
        if (mod->ex_table_start > mod->ex_table_end
            || (mod->ex_table_start &&
                !((unsigned long)mod->ex_table_start >= ((unsigned long)mod + mod->size_of_struct)
                  && ((unsigned long)mod->ex_table_end
                      < (unsigned long)mod + mod->size)))
            || (((unsigned long)mod->ex_table_start
                 - (unsigned long)mod->ex_table_end)
                % sizeof(struct exception_table_entry))) {
                printk(KERN_ERR "init_module: mod->ex_table_* invalid.\n");
                goto err2;
        }
        if (mod->flags & ~MOD_AUTOCLEAN) {
                printk(KERN_ERR "init_module: mod->flags invalid.\n");
                goto err2;
        }
        if (mod_member_present(mod, can_unload)
            && mod->can_unload && !mod_bound(mod->can_unload, 0, mod)) {
                printk(KERN_ERR "init_module: mod->can_unload out of bounds.\n");
                goto err2;
        }
        if (mod_member_present(mod, kallsyms_end)) {
            if (mod->kallsyms_end &&
                (!mod_bound(mod->kallsyms_start, 0, mod) ||
                 !mod_bound(mod->kallsyms_end, 0, mod))) {
                printk(KERN_ERR "init_module: mod->kallsyms out of bounds.\n");
                goto err2;
            }
            if (mod->kallsyms_start > mod->kallsyms_end) {
                printk(KERN_ERR "init_module: mod->kallsyms invalid.\n");
                goto err2;
            }
        }
        if (mod_member_present(mod, archdata_end)) {
            if (mod->archdata_end &&
                (!mod_bound(mod->archdata_start, 0, mod) ||
                 !mod_bound(mod->archdata_end, 0, mod))) {
                printk(KERN_ERR "init_module: mod->archdata out of bounds.\n");
                goto err2;
            }
            if (mod->archdata_start > mod->archdata_end) {
                printk(KERN_ERR "init_module: mod->archdata invalid.\n");
                goto err2;
            }
        }
        if (mod_member_present(mod, kernel_data) && mod->kernel_data) {
            printk(KERN_ERR "init_module: mod->kernel_data must be zero.\n");
            goto err2;
        }

        /* Check that the user isn't doing something silly with the name.  */

        if ((n_namelen = get_mod_name(mod->name - (unsigned long)mod
                                      + (unsigned long)mod_user,
                                      &n_name)) < 0) {
                printk(KERN_ERR "init_module: get_mod_name failure.\n");
                error = n_namelen;
                goto err2;
        }
        if (namelen != n_namelen || strcmp(n_name, name_tmp) != 0) {
                printk(KERN_ERR "init_module: changed module name to "
                                "`%s' from `%s'\n",
                       n_name, name_tmp);
                goto err3;
        }

        /* Ok, that's about all the sanity we can stomach; copy the rest.  */

        if (copy_from_user((char *)mod+mod_user_size,
                           (char *)mod_user+mod_user_size,
                           mod->size-mod_user_size)) {
                error = -EFAULT;
                goto err3;
        }

        if (module_arch_init(mod))
                goto err3;

        /* On some machines it is necessary to do something here
           to make the I and D caches consistent.  */
        flush_icache_range((unsigned long)mod, (unsigned long)mod + mod->size);

        mod->refs = NULL;

        /* Sanity check the module's dependents */
        for (i = 0, dep = mod->deps; i < mod->ndeps; ++i, ++dep) {
                struct module *o, *d = dep->dep;

                /* Make sure the indicated dependencies are really modules.  */
                if (d == mod) {
                        printk(KERN_ERR "init_module: self-referential "
                                        "dependency in mod->deps.\n");
                        goto err3;
                }

                /* Scan the current modules for this dependency */
                for (o = module_list; o != &kernel_module && o != d; o = o->next)
                        ;

                if (o != d) {
                        printk(KERN_ERR "init_module: found dependency that is "
                                "(no longer?) a module.\n");
                        goto err3;
                }
        }

        /* Update module references.  */
        for (i = 0, dep = mod->deps; i < mod->ndeps; ++i, ++dep) {
                struct module *d = dep->dep;

                dep->ref = mod;
                dep->next_ref = d->refs;
                d->refs = dep;
                /* Being referenced by a dependent module counts as a
                   use as far as kmod is concerned.  */
                d->flags |= MOD_USED_ONCE;
        }

        /* Free our temporary memory.  */
        put_mod_name(n_name);
        put_mod_name(name);

        /* Initialize the module.  */
        atomic_set(&mod->uc.usecount,1);
        mod->flags |= MOD_INITIALIZING;
        if (mod->init && (error = mod->init()) != 0) {
                atomic_set(&mod->uc.usecount,0);
                mod->flags &= ~MOD_INITIALIZING;
                if (error > 0)  /* Buggy module */
                        error = -EBUSY;
                goto err0;
        }
        atomic_dec(&mod->uc.usecount);

        /* And set it running.  */
        mod->flags = (mod->flags | MOD_RUNNING) & ~MOD_INITIALIZING;
        error = 0;
        goto err0;

err3:
        put_mod_name(n_name);
err2:
        *mod = mod_tmp;
        strcpy((char *)mod->name, name_tmp);    /* We know there is room for this */
err1:
        put_mod_name(name);
err0:
        if (mod2)
                vfree(mod2);
        unlock_kernel();
        kfree(name_tmp);
        return error;
}

static spinlock_t unload_lock = SPIN_LOCK_UNLOCKED;
int try_inc_mod_count(struct module *mod)
{
        int res = 1;
        if (mod) {
                spin_lock(&unload_lock);
                if (mod->flags & MOD_DELETED)
                        res = 0;
                else
                        __MOD_INC_USE_COUNT(mod);
                spin_unlock(&unload_lock);
        }
        return res;
}

asmlinkage long
sys_delete_module(const char *name_user)
{
        struct module *mod, *next;
        char *name;
        long error;
        int something_changed;

        if (!capable(CAP_SYS_MODULE))
                return -EPERM;

        lock_kernel();
        if (name_user) {
                if ((error = get_mod_name(name_user, &name)) < 0)
                        goto out;
                error = -ENOENT;
                if ((mod = find_module(name)) == NULL) {
                        put_mod_name(name);
                        goto out;
                }
                put_mod_name(name);
                error = -EBUSY;
                if (mod->refs != NULL)
                        goto out;

                spin_lock(&unload_lock);
                if (!__MOD_IN_USE(mod)) {
                        mod->flags |= MOD_DELETED;
                        spin_unlock(&unload_lock);
                        free_module(mod, 0);
                        error = 0;
                } else {
                        spin_unlock(&unload_lock);
                }
                goto out;
        }

        /* Do automatic reaping */
restart:
        something_changed = 0;
        
        for (mod = module_list; mod != &kernel_module; mod = next) {
                next = mod->next;
                spin_lock(&unload_lock);
                if (mod->refs == NULL
                    && (mod->flags & MOD_AUTOCLEAN)
                    && (mod->flags & MOD_RUNNING)
                    && !(mod->flags & MOD_DELETED)
                    && (mod->flags & MOD_USED_ONCE)
                    && !__MOD_IN_USE(mod)) {
                        if ((mod->flags & MOD_VISITED)
                            && !(mod->flags & MOD_JUST_FREED)) {
                                spin_unlock(&unload_lock);
                                mod->flags &= ~MOD_VISITED;
                        } else {
                                mod->flags |= MOD_DELETED;
                                spin_unlock(&unload_lock);
                                free_module(mod, 1);
                                something_changed = 1;
                        }
                } else {
                        spin_unlock(&unload_lock);
                }
        }
        
        if (something_changed)
                goto restart;
                
        for (mod = module_list; mod != &kernel_module; mod = mod->next)
                mod->flags &= ~MOD_JUST_FREED;
        
        error = 0;
out:
        unlock_kernel();
        return error;
}

/* Query various bits about modules.  */

static int
qm_modules(char *buf, size_t bufsize, size_t *ret)
{
        struct module *mod;
        size_t nmod, space, len;

        nmod = space = 0;

        for (mod=module_list; mod != &kernel_module; mod=mod->next, ++nmod) {
                len = strlen(mod->name)+1;
                if (len > bufsize)
                        goto calc_space_needed;
                if (copy_to_user(buf, mod->name, len))
                        return -EFAULT;
                buf += len;
                bufsize -= len;
                space += len;
        }

        if (put_user(nmod, ret))
                return -EFAULT;
        else
                return 0;

calc_space_needed:
        space += len;
        while ((mod = mod->next) != &kernel_module)
                space += strlen(mod->name)+1;

        if (put_user(space, ret))
                return -EFAULT;
        else
                return -ENOSPC;
}

static int
qm_deps(struct module *mod, char *buf, size_t bufsize, size_t *ret)
{
        size_t i, space, len;

        if (mod == &kernel_module)
                return -EINVAL;
        if (!MOD_CAN_QUERY(mod))
                if (put_user(0, ret))
                        return -EFAULT;
                else
                        return 0;

        space = 0;
        for (i = 0; i < mod->ndeps; ++i) {
                const char *dep_name = mod->deps[i].dep->name;

                len = strlen(dep_name)+1;
                if (len > bufsize)
                        goto calc_space_needed;
                if (copy_to_user(buf, dep_name, len))
                        return -EFAULT;
                buf += len;
                bufsize -= len;
                space += len;
        }

        if (put_user(i, ret))
                return -EFAULT;
        else
                return 0;

calc_space_needed:
        space += len;
        while (++i < mod->ndeps)
                space += strlen(mod->deps[i].dep->name)+1;

        if (put_user(space, ret))
                return -EFAULT;
        else
                return -ENOSPC;
}

static int
qm_refs(struct module *mod, char *buf, size_t bufsize, size_t *ret)
{
        size_t nrefs, space, len;
        struct module_ref *ref;

        if (mod == &kernel_module)
                return -EINVAL;
        if (!MOD_CAN_QUERY(mod))
                if (put_user(0, ret))
                        return -EFAULT;
                else
                        return 0;

        space = 0;
        for (nrefs = 0, ref = mod->refs; ref ; ++nrefs, ref = ref->next_ref) {
                const char *ref_name = ref->ref->name;

                len = strlen(ref_name)+1;
                if (len > bufsize)
                        goto calc_space_needed;
                if (copy_to_user(buf, ref_name, len))
                        return -EFAULT;
                buf += len;
                bufsize -= len;
                space += len;
        }

        if (put_user(nrefs, ret))
                return -EFAULT;
        else
                return 0;

calc_space_needed:
        space += len;
        while ((ref = ref->next_ref) != NULL)
                space += strlen(ref->ref->name)+1;

        if (put_user(space, ret))
                return -EFAULT;
        else
                return -ENOSPC;
}

static int
qm_symbols(struct module *mod, char *buf, size_t bufsize, size_t *ret)
{
        size_t i, space, len;
        struct module_symbol *s;
        char *strings;
        unsigned long *vals;

        if (!MOD_CAN_QUERY(mod))
                if (put_user(0, ret))
                        return -EFAULT;
                else
                        return 0;

        space = mod->nsyms * 2*sizeof(void *);

        i = len = 0;
        s = mod->syms;

        if (space > bufsize)
                goto calc_space_needed;

        if (!access_ok(VERIFY_WRITE, buf, space))
                return -EFAULT;

        bufsize -= space;
        vals = (unsigned long *)buf;
        strings = buf+space;

        for (; i < mod->nsyms ; ++i, ++s, vals += 2) {
                len = strlen(s->name)+1;
                if (len > bufsize)
                        goto calc_space_needed;

                if (copy_to_user(strings, s->name, len)
                    || __put_user(s->value, vals+0)
                    || __put_user(space, vals+1))
                        return -EFAULT;

                strings += len;
                bufsize -= len;
                space += len;
        }
        if (put_user(i, ret))
                return -EFAULT;
        else
                return 0;

calc_space_needed:
        for (; i < mod->nsyms; ++i, ++s)
                space += strlen(s->name)+1;

        if (put_user(space, ret))
                return -EFAULT;
        else
                return -ENOSPC;
}

static int
qm_info(struct module *mod, char *buf, size_t bufsize, size_t *ret)
{
        int error = 0;

        if (mod == &kernel_module)
                return -EINVAL;

        if (sizeof(struct module_info) <= bufsize) {
                struct module_info info;
                info.addr = (unsigned long)mod;
                info.size = mod->size;
                info.flags = mod->flags;
                
                /* usecount is one too high here - report appropriately to
                   compensate for locking */
                info.usecount = (mod_member_present(mod, can_unload)
                                 && mod->can_unload ? -1 : atomic_read(&mod->uc.usecount)-1);

                if (copy_to_user(buf, &info, sizeof(struct module_info)))
                        return -EFAULT;
        } else
                error = -ENOSPC;

        if (put_user(sizeof(struct module_info), ret))
                return -EFAULT;

        return error;
}

asmlinkage long
sys_query_module(const char *name_user, int which, char *buf, size_t bufsize,
                 size_t *ret)
{
        struct module *mod;
        int err;

        lock_kernel();
        if (name_user == NULL)
                mod = &kernel_module;
        else {
                long namelen;
                char *name;

                if ((namelen = get_mod_name(name_user, &name)) < 0) {
                        err = namelen;
                        goto out;
                }
                err = -ENOENT;
                if ((mod = find_module(name)) == NULL) {
                        put_mod_name(name);
                        goto out;
                }
                put_mod_name(name);
        }

        /* __MOD_ touches the flags. We must avoid that */
        
        atomic_inc(&mod->uc.usecount);
                
        switch (which)
        {
        case 0:
                err = 0;
                break;
        case QM_MODULES:
                err = qm_modules(buf, bufsize, ret);
                break;
        case QM_DEPS:
                err = qm_deps(mod, buf, bufsize, ret);
                break;
        case QM_REFS:
                err = qm_refs(mod, buf, bufsize, ret);
                break;
        case QM_SYMBOLS:
                err = qm_symbols(mod, buf, bufsize, ret);
                break;
        case QM_INFO:
                err = qm_info(mod, buf, bufsize, ret);
                break;
        default:
                err = -EINVAL;
                break;
        }
        atomic_dec(&mod->uc.usecount);
        
out:
        unlock_kernel();
        return err;
}

/*
 * Copy the kernel symbol table to user space.  If the argument is
 * NULL, just return the size of the table.
 *
 * This call is obsolete.  New programs should use query_module+QM_SYMBOLS
 * which does not arbitrarily limit the length of symbols.
 */

asmlinkage long
sys_get_kernel_syms(struct kernel_sym *table)
{
        struct module *mod;
        int i;
        struct kernel_sym ksym;

        lock_kernel();
        for (mod = module_list, i = 0; mod; mod = mod->next) {
                /* include the count for the module name! */
                i += mod->nsyms + 1;
        }

        if (table == NULL)
                goto out;

        /* So that we don't give the user our stack content */
        memset (&ksym, 0, sizeof (ksym));

        for (mod = module_list, i = 0; mod; mod = mod->next) {
                struct module_symbol *msym;
                unsigned int j;

                if (!MOD_CAN_QUERY(mod))
                        continue;

                /* magic: write module info as a pseudo symbol */
                ksym.value = (unsigned long)mod;
                ksym.name[0] = '#';
                strncpy(ksym.name+1, mod->name, sizeof(ksym.name)-1);
                ksym.name[sizeof(ksym.name)-1] = '\0';

                if (copy_to_user(table, &ksym, sizeof(ksym)) != 0)
                        goto out;
                ++i, ++table;

                if (mod->nsyms == 0)
                        continue;

                for (j = 0, msym = mod->syms; j < mod->nsyms; ++j, ++msym) {
                        ksym.value = msym->value;
                        strncpy(ksym.name, msym->name, sizeof(ksym.name));
                        ksym.name[sizeof(ksym.name)-1] = '\0';

                        if (copy_to_user(table, &ksym, sizeof(ksym)) != 0)
                                goto out;
                        ++i, ++table;
                }
        }
out:
        unlock_kernel();
        return i;
}

/*
 * Look for a module by name, ignoring modules marked for deletion.
 */

struct module *
find_module(const char *name)
{
        struct module *mod;

        for (mod = module_list; mod ; mod = mod->next) {
                if (mod->flags & MOD_DELETED)
                        continue;
                if (!strcmp(mod->name, name))
                        break;
        }

        return mod;
}

/*
 * Free the given module.
 */

void
free_module(struct module *mod, int tag_freed)
{
        struct module_ref *dep;
        unsigned i;
        unsigned long flags;

        /* Let the module clean up.  */

        if (mod->flags & MOD_RUNNING)
        {
                if(mod->cleanup)
                        mod->cleanup();
                mod->flags &= ~MOD_RUNNING;
        }

        /* Remove the module from the dependency lists.  */

        for (i = 0, dep = mod->deps; i < mod->ndeps; ++i, ++dep) {
                struct module_ref **pp;
                for (pp = &dep->dep->refs; *pp != dep; pp = &(*pp)->next_ref)
                        continue;
                *pp = dep->next_ref;
                if (tag_freed && dep->dep->refs == NULL)
                        dep->dep->flags |= MOD_JUST_FREED;
        }

        /* And from the main module list.  */

        spin_lock_irqsave(&modlist_lock, flags);
        if (mod == module_list) {
                module_list = mod->next;
        } else {
                struct module *p;
                for (p = module_list; p->next != mod; p = p->next)
                        continue;
                p->next = mod->next;
        }
        spin_unlock_irqrestore(&modlist_lock, flags);

        /* And free the memory.  */

        module_unmap(mod);
}

/*
 * Called by the /proc file system to return a current list of modules.
 */

int get_module_list(char *p)
{
        size_t left = PAGE_SIZE;
        struct module *mod;
        char tmpstr[64];
        struct module_ref *ref;

        for (mod = module_list; mod != &kernel_module; mod = mod->next) {
                long len;
                const char *q;

#define safe_copy_str(str, len)                                         \
                do {                                                    \
                        if (left < len)                                 \
                                goto fini;                              \
                        memcpy(p, str, len); p += len, left -= len;     \
                } while (0)
#define safe_copy_cstr(str)     safe_copy_str(str, sizeof(str)-1)

                len = strlen(mod->name);
                safe_copy_str(mod->name, len);

                if ((len = 20 - len) > 0) {
                        if (left < len)
                                goto fini;
                        memset(p, ' ', len);
                        p += len;
                        left -= len;
                }

                len = sprintf(tmpstr, "%8lu", mod->size);
                safe_copy_str(tmpstr, len);

                if (mod->flags & MOD_RUNNING) {
                        len = sprintf(tmpstr, "%4ld",
                                      (mod_member_present(mod, can_unload)
                                       && mod->can_unload
                                       ? -1L : (long)atomic_read(&mod->uc.usecount)));
                        safe_copy_str(tmpstr, len);
                }

                if (mod->flags & MOD_DELETED)
                        safe_copy_cstr(" (deleted)");
                else if (mod->flags & MOD_RUNNING) {
                        if (mod->flags & MOD_AUTOCLEAN)
                                safe_copy_cstr(" (autoclean)");
                        if (!(mod->flags & MOD_USED_ONCE))
                                safe_copy_cstr(" (unused)");
                }
                else if (mod->flags & MOD_INITIALIZING)
                        safe_copy_cstr(" (initializing)");
                else
                        safe_copy_cstr(" (uninitialized)");

                if ((ref = mod->refs) != NULL) {
                        safe_copy_cstr(" [");
                        while (1) {
                                q = ref->ref->name;
                                len = strlen(q);
                                safe_copy_str(q, len);

                                if ((ref = ref->next_ref) != NULL)
                                        safe_copy_cstr(" ");
                                else
                                        break;
                        }
                        safe_copy_cstr("]");
                }
                safe_copy_cstr("\n");

#undef safe_copy_str
#undef safe_copy_cstr
        }

fini:
        return PAGE_SIZE - left;
}

/*
 * Called by the /proc file system to return a current list of ksyms.
 */

struct mod_sym {
        struct module *mod;
        int index;
};

/* iterator */

static void *s_start(struct seq_file *m, loff_t *pos)
{
        struct mod_sym *p = kmalloc(sizeof(*p), GFP_KERNEL);
        struct module *v;
        loff_t n = *pos;

        if (!p)
                return ERR_PTR(-ENOMEM);
        lock_kernel();
        for (v = module_list, n = *pos; v; n -= v->nsyms, v = v->next) {
                if (n < v->nsyms) {
                        p->mod = v;
                        p->index = n;
                        return p;
                }
        }
        unlock_kernel();
        kfree(p);
        return NULL;
}

static void *s_next(struct seq_file *m, void *p, loff_t *pos)
{
        struct mod_sym *v = p;
        (*pos)++;
        if (++v->index >= v->mod->nsyms) {
                do {
                        v->mod = v->mod->next;
                        if (!v->mod) {
                                unlock_kernel();
                                kfree(p);
                                return NULL;
                        }
                } while (!v->mod->nsyms);
                v->index = 0;
        }
        return p;
}

static void s_stop(struct seq_file *m, void *p)
{
        if (p && !IS_ERR(p)) {
                unlock_kernel();
                kfree(p);
        }
}

static int s_show(struct seq_file *m, void *p)
{
        struct mod_sym *v = p;
        struct module_symbol *sym;

        if (!MOD_CAN_QUERY(v->mod))
                return 0;
        sym = &v->mod->syms[v->index];
        if (*v->mod->name)
                seq_printf(m, "%0*lx %s\t[%s]\n", (int)(2*sizeof(void*)),
                               sym->value, sym->name, v->mod->name);
        else
                seq_printf(m, "%0*lx %s\n", (int)(2*sizeof(void*)),
                               sym->value, sym->name);
        return 0;
}

struct seq_operations ksyms_op = {
        start:  s_start,
        next:   s_next,
        stop:   s_stop,
        show:   s_show
};

#else           /* CONFIG_MODULES */

/* Dummy syscalls for people who don't want modules */

asmlinkage unsigned long
sys_create_module(const char *name_user, size_t size)
{
        return -ENOSYS;
}

asmlinkage long
sys_init_module(const char *name_user, struct module *mod_user)
{
        return -ENOSYS;
}

asmlinkage long
sys_delete_module(const char *name_user)
{
        return -ENOSYS;
}

asmlinkage long
sys_query_module(const char *name_user, int which, char *buf, size_t bufsize,
                 size_t *ret)
{
        /* Let the program know about the new interface.  Not that
           it'll do them much good.  */
        if (which == 0)
                return 0;

        return -ENOSYS;
}

asmlinkage long
sys_get_kernel_syms(struct kernel_sym *table)
{
        return -ENOSYS;
}

int try_inc_mod_count(struct module *mod)
{
        return 1;
}

#endif  /* CONFIG_MODULES */