The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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

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    1 /*-
    2  * Copyright (c) 1997-2000 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 
   27 #include <sys/cdefs.h>
   28 __FBSDID("$FreeBSD: releng/10.1/sys/kern/kern_linker.c 264370 2014-04-12 14:18:25Z kib $");
   29 
   30 #include "opt_ddb.h"
   31 #include "opt_kld.h"
   32 #include "opt_hwpmc_hooks.h"
   33 
   34 #include <sys/param.h>
   35 #include <sys/kernel.h>
   36 #include <sys/systm.h>
   37 #include <sys/malloc.h>
   38 #include <sys/sysproto.h>
   39 #include <sys/sysent.h>
   40 #include <sys/priv.h>
   41 #include <sys/proc.h>
   42 #include <sys/lock.h>
   43 #include <sys/mutex.h>
   44 #include <sys/sx.h>
   45 #include <sys/module.h>
   46 #include <sys/mount.h>
   47 #include <sys/linker.h>
   48 #include <sys/eventhandler.h>
   49 #include <sys/fcntl.h>
   50 #include <sys/jail.h>
   51 #include <sys/libkern.h>
   52 #include <sys/namei.h>
   53 #include <sys/vnode.h>
   54 #include <sys/syscallsubr.h>
   55 #include <sys/sysctl.h>
   56 
   57 #include <net/vnet.h>
   58 
   59 #include <security/mac/mac_framework.h>
   60 
   61 #include "linker_if.h"
   62 
   63 #ifdef HWPMC_HOOKS
   64 #include <sys/pmckern.h>
   65 #endif
   66 
   67 #ifdef KLD_DEBUG
   68 int kld_debug = 0;
   69 SYSCTL_INT(_debug, OID_AUTO, kld_debug, CTLFLAG_RW | CTLFLAG_TUN,
   70     &kld_debug, 0, "Set various levels of KLD debug");
   71 TUNABLE_INT("debug.kld_debug", &kld_debug);
   72 #endif
   73 
   74 /*
   75  * static char *linker_search_path(const char *name, struct mod_depend
   76  * *verinfo);
   77  */
   78 static const char       *linker_basename(const char *path);
   79 
   80 /*
   81  * Find a currently loaded file given its filename.
   82  */
   83 static linker_file_t linker_find_file_by_name(const char* _filename);
   84 
   85 /*
   86  * Find a currently loaded file given its file id.
   87  */
   88 static linker_file_t linker_find_file_by_id(int _fileid);
   89 
   90 /* Metadata from the static kernel */
   91 SET_DECLARE(modmetadata_set, struct mod_metadata);
   92 
   93 MALLOC_DEFINE(M_LINKER, "linker", "kernel linker");
   94 
   95 linker_file_t linker_kernel_file;
   96 
   97 static struct sx kld_sx;        /* kernel linker lock */
   98 
   99 /*
  100  * Load counter used by clients to determine if a linker file has been
  101  * re-loaded. This counter is incremented for each file load.
  102  */
  103 static int loadcnt;
  104 
  105 static linker_class_list_t classes;
  106 static linker_file_list_t linker_files;
  107 static int next_file_id = 1;
  108 static int linker_no_more_classes = 0;
  109 
  110 #define LINKER_GET_NEXT_FILE_ID(a) do {                                 \
  111         linker_file_t lftmp;                                            \
  112                                                                         \
  113         if (!cold)                                                      \
  114                 sx_assert(&kld_sx, SA_XLOCKED);                         \
  115 retry:                                                                  \
  116         TAILQ_FOREACH(lftmp, &linker_files, link) {                     \
  117                 if (next_file_id == lftmp->id) {                        \
  118                         next_file_id++;                                 \
  119                         goto retry;                                     \
  120                 }                                                       \
  121         }                                                               \
  122         (a) = next_file_id;                                             \
  123 } while(0)
  124 
  125 
  126 /* XXX wrong name; we're looking at version provision tags here, not modules */
  127 typedef TAILQ_HEAD(, modlist) modlisthead_t;
  128 struct modlist {
  129         TAILQ_ENTRY(modlist) link;      /* chain together all modules */
  130         linker_file_t   container;
  131         const char      *name;
  132         int             version;
  133 };
  134 typedef struct modlist *modlist_t;
  135 static modlisthead_t found_modules;
  136 
  137 static int      linker_file_add_dependency(linker_file_t file,
  138                     linker_file_t dep);
  139 static caddr_t  linker_file_lookup_symbol_internal(linker_file_t file,
  140                     const char* name, int deps);
  141 static int      linker_load_module(const char *kldname,
  142                     const char *modname, struct linker_file *parent,
  143                     struct mod_depend *verinfo, struct linker_file **lfpp);
  144 static modlist_t modlist_lookup2(const char *name, struct mod_depend *verinfo);
  145 
  146 static void
  147 linker_init(void *arg)
  148 {
  149 
  150         sx_init(&kld_sx, "kernel linker");
  151         TAILQ_INIT(&classes);
  152         TAILQ_INIT(&linker_files);
  153 }
  154 
  155 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0);
  156 
  157 static void
  158 linker_stop_class_add(void *arg)
  159 {
  160 
  161         linker_no_more_classes = 1;
  162 }
  163 
  164 SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL);
  165 
  166 int
  167 linker_add_class(linker_class_t lc)
  168 {
  169 
  170         /*
  171          * We disallow any class registration past SI_ORDER_ANY
  172          * of SI_SUB_KLD.  We bump the reference count to keep the
  173          * ops from being freed.
  174          */
  175         if (linker_no_more_classes == 1)
  176                 return (EPERM);
  177         kobj_class_compile((kobj_class_t) lc);
  178         ((kobj_class_t)lc)->refs++;     /* XXX: kobj_mtx */
  179         TAILQ_INSERT_TAIL(&classes, lc, link);
  180         return (0);
  181 }
  182 
  183 static void
  184 linker_file_sysinit(linker_file_t lf)
  185 {
  186         struct sysinit **start, **stop, **sipp, **xipp, *save;
  187 
  188         KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n",
  189             lf->filename));
  190 
  191         sx_assert(&kld_sx, SA_XLOCKED);
  192 
  193         if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0)
  194                 return;
  195         /*
  196          * Perform a bubble sort of the system initialization objects by
  197          * their subsystem (primary key) and order (secondary key).
  198          *
  199          * Since some things care about execution order, this is the operation
  200          * which ensures continued function.
  201          */
  202         for (sipp = start; sipp < stop; sipp++) {
  203                 for (xipp = sipp + 1; xipp < stop; xipp++) {
  204                         if ((*sipp)->subsystem < (*xipp)->subsystem ||
  205                             ((*sipp)->subsystem == (*xipp)->subsystem &&
  206                             (*sipp)->order <= (*xipp)->order))
  207                                 continue;       /* skip */
  208                         save = *sipp;
  209                         *sipp = *xipp;
  210                         *xipp = save;
  211                 }
  212         }
  213 
  214         /*
  215          * Traverse the (now) ordered list of system initialization tasks.
  216          * Perform each task, and continue on to the next task.
  217          */
  218         sx_xunlock(&kld_sx);
  219         mtx_lock(&Giant);
  220         for (sipp = start; sipp < stop; sipp++) {
  221                 if ((*sipp)->subsystem == SI_SUB_DUMMY)
  222                         continue;       /* skip dummy task(s) */
  223 
  224                 /* Call function */
  225                 (*((*sipp)->func)) ((*sipp)->udata);
  226         }
  227         mtx_unlock(&Giant);
  228         sx_xlock(&kld_sx);
  229 }
  230 
  231 static void
  232 linker_file_sysuninit(linker_file_t lf)
  233 {
  234         struct sysinit **start, **stop, **sipp, **xipp, *save;
  235 
  236         KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n",
  237             lf->filename));
  238 
  239         sx_assert(&kld_sx, SA_XLOCKED);
  240 
  241         if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop,
  242             NULL) != 0)
  243                 return;
  244 
  245         /*
  246          * Perform a reverse bubble sort of the system initialization objects
  247          * by their subsystem (primary key) and order (secondary key).
  248          *
  249          * Since some things care about execution order, this is the operation
  250          * which ensures continued function.
  251          */
  252         for (sipp = start; sipp < stop; sipp++) {
  253                 for (xipp = sipp + 1; xipp < stop; xipp++) {
  254                         if ((*sipp)->subsystem > (*xipp)->subsystem ||
  255                             ((*sipp)->subsystem == (*xipp)->subsystem &&
  256                             (*sipp)->order >= (*xipp)->order))
  257                                 continue;       /* skip */
  258                         save = *sipp;
  259                         *sipp = *xipp;
  260                         *xipp = save;
  261                 }
  262         }
  263 
  264         /*
  265          * Traverse the (now) ordered list of system initialization tasks.
  266          * Perform each task, and continue on to the next task.
  267          */
  268         sx_xunlock(&kld_sx);
  269         mtx_lock(&Giant);
  270         for (sipp = start; sipp < stop; sipp++) {
  271                 if ((*sipp)->subsystem == SI_SUB_DUMMY)
  272                         continue;       /* skip dummy task(s) */
  273 
  274                 /* Call function */
  275                 (*((*sipp)->func)) ((*sipp)->udata);
  276         }
  277         mtx_unlock(&Giant);
  278         sx_xlock(&kld_sx);
  279 }
  280 
  281 static void
  282 linker_file_register_sysctls(linker_file_t lf)
  283 {
  284         struct sysctl_oid **start, **stop, **oidp;
  285 
  286         KLD_DPF(FILE,
  287             ("linker_file_register_sysctls: registering SYSCTLs for %s\n",
  288             lf->filename));
  289 
  290         sx_assert(&kld_sx, SA_XLOCKED);
  291 
  292         if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
  293                 return;
  294 
  295         sx_xunlock(&kld_sx);
  296         sysctl_lock();
  297         for (oidp = start; oidp < stop; oidp++)
  298                 sysctl_register_oid(*oidp);
  299         sysctl_unlock();
  300         sx_xlock(&kld_sx);
  301 }
  302 
  303 static void
  304 linker_file_unregister_sysctls(linker_file_t lf)
  305 {
  306         struct sysctl_oid **start, **stop, **oidp;
  307 
  308         KLD_DPF(FILE, ("linker_file_unregister_sysctls: unregistering SYSCTLs"
  309             " for %s\n", lf->filename));
  310 
  311         sx_assert(&kld_sx, SA_XLOCKED);
  312 
  313         if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
  314                 return;
  315 
  316         sx_xunlock(&kld_sx);
  317         sysctl_lock();
  318         for (oidp = start; oidp < stop; oidp++)
  319                 sysctl_unregister_oid(*oidp);
  320         sysctl_unlock();
  321         sx_xlock(&kld_sx);
  322 }
  323 
  324 static int
  325 linker_file_register_modules(linker_file_t lf)
  326 {
  327         struct mod_metadata **start, **stop, **mdp;
  328         const moduledata_t *moddata;
  329         int first_error, error;
  330 
  331         KLD_DPF(FILE, ("linker_file_register_modules: registering modules"
  332             " in %s\n", lf->filename));
  333 
  334         sx_assert(&kld_sx, SA_XLOCKED);
  335 
  336         if (linker_file_lookup_set(lf, "modmetadata_set", &start,
  337             &stop, NULL) != 0) {
  338                 /*
  339                  * This fallback should be unnecessary, but if we get booted
  340                  * from boot2 instead of loader and we are missing our
  341                  * metadata then we have to try the best we can.
  342                  */
  343                 if (lf == linker_kernel_file) {
  344                         start = SET_BEGIN(modmetadata_set);
  345                         stop = SET_LIMIT(modmetadata_set);
  346                 } else
  347                         return (0);
  348         }
  349         first_error = 0;
  350         for (mdp = start; mdp < stop; mdp++) {
  351                 if ((*mdp)->md_type != MDT_MODULE)
  352                         continue;
  353                 moddata = (*mdp)->md_data;
  354                 KLD_DPF(FILE, ("Registering module %s in %s\n",
  355                     moddata->name, lf->filename));
  356                 error = module_register(moddata, lf);
  357                 if (error) {
  358                         printf("Module %s failed to register: %d\n",
  359                             moddata->name, error);
  360                         if (first_error == 0)
  361                                 first_error = error;
  362                 }
  363         }
  364         return (first_error);
  365 }
  366 
  367 static void
  368 linker_init_kernel_modules(void)
  369 {
  370 
  371         sx_xlock(&kld_sx);
  372         linker_file_register_modules(linker_kernel_file);
  373         sx_xunlock(&kld_sx);
  374 }
  375 
  376 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules,
  377     0);
  378 
  379 static int
  380 linker_load_file(const char *filename, linker_file_t *result)
  381 {
  382         linker_class_t lc;
  383         linker_file_t lf;
  384         int foundfile, error, modules;
  385 
  386         /* Refuse to load modules if securelevel raised */
  387         if (prison0.pr_securelevel > 0)
  388                 return (EPERM);
  389 
  390         sx_assert(&kld_sx, SA_XLOCKED);
  391         lf = linker_find_file_by_name(filename);
  392         if (lf) {
  393                 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded,"
  394                     " incrementing refs\n", filename));
  395                 *result = lf;
  396                 lf->refs++;
  397                 return (0);
  398         }
  399         foundfile = 0;
  400         error = 0;
  401 
  402         /*
  403          * We do not need to protect (lock) classes here because there is
  404          * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY)
  405          * and there is no class deregistration mechanism at this time.
  406          */
  407         TAILQ_FOREACH(lc, &classes, link) {
  408                 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n",
  409                     filename));
  410                 error = LINKER_LOAD_FILE(lc, filename, &lf);
  411                 /*
  412                  * If we got something other than ENOENT, then it exists but
  413                  * we cannot load it for some other reason.
  414                  */
  415                 if (error != ENOENT)
  416                         foundfile = 1;
  417                 if (lf) {
  418                         error = linker_file_register_modules(lf);
  419                         if (error == EEXIST) {
  420                                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
  421                                 return (error);
  422                         }
  423                         modules = !TAILQ_EMPTY(&lf->modules);
  424                         linker_file_register_sysctls(lf);
  425                         linker_file_sysinit(lf);
  426                         lf->flags |= LINKER_FILE_LINKED;
  427 
  428                         /*
  429                          * If all of the modules in this file failed
  430                          * to load, unload the file and return an
  431                          * error of ENOEXEC.
  432                          */
  433                         if (modules && TAILQ_EMPTY(&lf->modules)) {
  434                                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
  435                                 return (ENOEXEC);
  436                         }
  437                         EVENTHANDLER_INVOKE(kld_load, lf);
  438                         *result = lf;
  439                         return (0);
  440                 }
  441         }
  442         /*
  443          * Less than ideal, but tells the user whether it failed to load or
  444          * the module was not found.
  445          */
  446         if (foundfile) {
  447 
  448                 /*
  449                  * If the file type has not been recognized by the last try
  450                  * printout a message before to fail.
  451                  */
  452                 if (error == ENOSYS)
  453                         printf("linker_load_file: Unsupported file type\n");
  454 
  455                 /*
  456                  * Format not recognized or otherwise unloadable.
  457                  * When loading a module that is statically built into
  458                  * the kernel EEXIST percolates back up as the return
  459                  * value.  Preserve this so that apps like sysinstall
  460                  * can recognize this special case and not post bogus
  461                  * dialog boxes.
  462                  */
  463                 if (error != EEXIST)
  464                         error = ENOEXEC;
  465         } else
  466                 error = ENOENT;         /* Nothing found */
  467         return (error);
  468 }
  469 
  470 int
  471 linker_reference_module(const char *modname, struct mod_depend *verinfo,
  472     linker_file_t *result)
  473 {
  474         modlist_t mod;
  475         int error;
  476 
  477         sx_xlock(&kld_sx);
  478         if ((mod = modlist_lookup2(modname, verinfo)) != NULL) {
  479                 *result = mod->container;
  480                 (*result)->refs++;
  481                 sx_xunlock(&kld_sx);
  482                 return (0);
  483         }
  484 
  485         error = linker_load_module(NULL, modname, NULL, verinfo, result);
  486         sx_xunlock(&kld_sx);
  487         return (error);
  488 }
  489 
  490 int
  491 linker_release_module(const char *modname, struct mod_depend *verinfo,
  492     linker_file_t lf)
  493 {
  494         modlist_t mod;
  495         int error;
  496 
  497         sx_xlock(&kld_sx);
  498         if (lf == NULL) {
  499                 KASSERT(modname != NULL,
  500                     ("linker_release_module: no file or name"));
  501                 mod = modlist_lookup2(modname, verinfo);
  502                 if (mod == NULL) {
  503                         sx_xunlock(&kld_sx);
  504                         return (ESRCH);
  505                 }
  506                 lf = mod->container;
  507         } else
  508                 KASSERT(modname == NULL && verinfo == NULL,
  509                     ("linker_release_module: both file and name"));
  510         error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL);
  511         sx_xunlock(&kld_sx);
  512         return (error);
  513 }
  514 
  515 static linker_file_t
  516 linker_find_file_by_name(const char *filename)
  517 {
  518         linker_file_t lf;
  519         char *koname;
  520 
  521         koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
  522         sprintf(koname, "%s.ko", filename);
  523 
  524         sx_assert(&kld_sx, SA_XLOCKED);
  525         TAILQ_FOREACH(lf, &linker_files, link) {
  526                 if (strcmp(lf->filename, koname) == 0)
  527                         break;
  528                 if (strcmp(lf->filename, filename) == 0)
  529                         break;
  530         }
  531         free(koname, M_LINKER);
  532         return (lf);
  533 }
  534 
  535 static linker_file_t
  536 linker_find_file_by_id(int fileid)
  537 {
  538         linker_file_t lf;
  539 
  540         sx_assert(&kld_sx, SA_XLOCKED);
  541         TAILQ_FOREACH(lf, &linker_files, link)
  542                 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED)
  543                         break;
  544         return (lf);
  545 }
  546 
  547 int
  548 linker_file_foreach(linker_predicate_t *predicate, void *context)
  549 {
  550         linker_file_t lf;
  551         int retval = 0;
  552 
  553         sx_xlock(&kld_sx);
  554         TAILQ_FOREACH(lf, &linker_files, link) {
  555                 retval = predicate(lf, context);
  556                 if (retval != 0)
  557                         break;
  558         }
  559         sx_xunlock(&kld_sx);
  560         return (retval);
  561 }
  562 
  563 linker_file_t
  564 linker_make_file(const char *pathname, linker_class_t lc)
  565 {
  566         linker_file_t lf;
  567         const char *filename;
  568 
  569         if (!cold)
  570                 sx_assert(&kld_sx, SA_XLOCKED);
  571         filename = linker_basename(pathname);
  572 
  573         KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname));
  574         lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK);
  575         if (lf == NULL)
  576                 return (NULL);
  577         lf->refs = 1;
  578         lf->userrefs = 0;
  579         lf->flags = 0;
  580         lf->filename = strdup(filename, M_LINKER);
  581         lf->pathname = strdup(pathname, M_LINKER);
  582         LINKER_GET_NEXT_FILE_ID(lf->id);
  583         lf->ndeps = 0;
  584         lf->deps = NULL;
  585         lf->loadcnt = ++loadcnt;
  586         STAILQ_INIT(&lf->common);
  587         TAILQ_INIT(&lf->modules);
  588         TAILQ_INSERT_TAIL(&linker_files, lf, link);
  589         return (lf);
  590 }
  591 
  592 int
  593 linker_file_unload(linker_file_t file, int flags)
  594 {
  595         module_t mod, next;
  596         modlist_t ml, nextml;
  597         struct common_symbol *cp;
  598         int error, i;
  599 
  600         /* Refuse to unload modules if securelevel raised. */
  601         if (prison0.pr_securelevel > 0)
  602                 return (EPERM);
  603 
  604         sx_assert(&kld_sx, SA_XLOCKED);
  605         KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
  606 
  607         /* Easy case of just dropping a reference. */
  608         if (file->refs > 1) {
  609                 file->refs--;
  610                 return (0);
  611         }
  612 
  613         /* Give eventhandlers a chance to prevent the unload. */
  614         error = 0;
  615         EVENTHANDLER_INVOKE(kld_unload_try, file, &error);
  616         if (error != 0)
  617                 return (EBUSY);
  618 
  619         KLD_DPF(FILE, ("linker_file_unload: file is unloading,"
  620             " informing modules\n"));
  621 
  622         /*
  623          * Quiesce all the modules to give them a chance to veto the unload.
  624          */
  625         MOD_SLOCK;
  626         for (mod = TAILQ_FIRST(&file->modules); mod;
  627              mod = module_getfnext(mod)) {
  628 
  629                 error = module_quiesce(mod);
  630                 if (error != 0 && flags != LINKER_UNLOAD_FORCE) {
  631                         KLD_DPF(FILE, ("linker_file_unload: module %s"
  632                             " vetoed unload\n", module_getname(mod)));
  633                         /*
  634                          * XXX: Do we need to tell all the quiesced modules
  635                          * that they can resume work now via a new module
  636                          * event?
  637                          */
  638                         MOD_SUNLOCK;
  639                         return (error);
  640                 }
  641         }
  642         MOD_SUNLOCK;
  643 
  644         /*
  645          * Inform any modules associated with this file that they are
  646          * being unloaded.
  647          */
  648         MOD_XLOCK;
  649         for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
  650                 next = module_getfnext(mod);
  651                 MOD_XUNLOCK;
  652 
  653                 /*
  654                  * Give the module a chance to veto the unload.
  655                  */
  656                 if ((error = module_unload(mod)) != 0) {
  657 #ifdef KLD_DEBUG
  658                         MOD_SLOCK;
  659                         KLD_DPF(FILE, ("linker_file_unload: module %s"
  660                             " failed unload\n", module_getname(mod)));
  661                         MOD_SUNLOCK;
  662 #endif
  663                         return (error);
  664                 }
  665                 MOD_XLOCK;
  666                 module_release(mod);
  667         }
  668         MOD_XUNLOCK;
  669 
  670         TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) {
  671                 if (ml->container == file) {
  672                         TAILQ_REMOVE(&found_modules, ml, link);
  673                         free(ml, M_LINKER);
  674                 }
  675         }
  676 
  677         /*
  678          * Don't try to run SYSUNINITs if we are unloaded due to a
  679          * link error.
  680          */
  681         if (file->flags & LINKER_FILE_LINKED) {
  682                 file->flags &= ~LINKER_FILE_LINKED;
  683                 linker_file_sysuninit(file);
  684                 linker_file_unregister_sysctls(file);
  685         }
  686         TAILQ_REMOVE(&linker_files, file, link);
  687 
  688         if (file->deps) {
  689                 for (i = 0; i < file->ndeps; i++)
  690                         linker_file_unload(file->deps[i], flags);
  691                 free(file->deps, M_LINKER);
  692                 file->deps = NULL;
  693         }
  694         while ((cp = STAILQ_FIRST(&file->common)) != NULL) {
  695                 STAILQ_REMOVE_HEAD(&file->common, link);
  696                 free(cp, M_LINKER);
  697         }
  698 
  699         LINKER_UNLOAD(file);
  700 
  701         EVENTHANDLER_INVOKE(kld_unload, file->filename, file->address,
  702             file->size);
  703 
  704         if (file->filename) {
  705                 free(file->filename, M_LINKER);
  706                 file->filename = NULL;
  707         }
  708         if (file->pathname) {
  709                 free(file->pathname, M_LINKER);
  710                 file->pathname = NULL;
  711         }
  712         kobj_delete((kobj_t) file, M_LINKER);
  713         return (0);
  714 }
  715 
  716 int
  717 linker_ctf_get(linker_file_t file, linker_ctf_t *lc)
  718 {
  719         return (LINKER_CTF_GET(file, lc));
  720 }
  721 
  722 static int
  723 linker_file_add_dependency(linker_file_t file, linker_file_t dep)
  724 {
  725         linker_file_t *newdeps;
  726 
  727         sx_assert(&kld_sx, SA_XLOCKED);
  728         file->deps = realloc(file->deps, (file->ndeps + 1) * sizeof(*newdeps),
  729             M_LINKER, M_WAITOK | M_ZERO);
  730         file->deps[file->ndeps] = dep;
  731         file->ndeps++;
  732         KLD_DPF(FILE, ("linker_file_add_dependency:"
  733             " adding %s as dependency for %s\n", 
  734             dep->filename, file->filename));
  735         return (0);
  736 }
  737 
  738 /*
  739  * Locate a linker set and its contents.  This is a helper function to avoid
  740  * linker_if.h exposure elsewhere.  Note: firstp and lastp are really void **.
  741  * This function is used in this file so we can avoid having lots of (void **)
  742  * casts.
  743  */
  744 int
  745 linker_file_lookup_set(linker_file_t file, const char *name,
  746     void *firstp, void *lastp, int *countp)
  747 {
  748 
  749         sx_assert(&kld_sx, SA_LOCKED);
  750         return (LINKER_LOOKUP_SET(file, name, firstp, lastp, countp));
  751 }
  752 
  753 /*
  754  * List all functions in a file.
  755  */
  756 int
  757 linker_file_function_listall(linker_file_t lf,
  758     linker_function_nameval_callback_t callback_func, void *arg)
  759 {
  760         return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg));
  761 }
  762 
  763 caddr_t
  764 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps)
  765 {
  766         caddr_t sym;
  767         int locked;
  768 
  769         locked = sx_xlocked(&kld_sx);
  770         if (!locked)
  771                 sx_xlock(&kld_sx);
  772         sym = linker_file_lookup_symbol_internal(file, name, deps);
  773         if (!locked)
  774                 sx_xunlock(&kld_sx);
  775         return (sym);
  776 }
  777 
  778 static caddr_t
  779 linker_file_lookup_symbol_internal(linker_file_t file, const char *name,
  780     int deps)
  781 {
  782         c_linker_sym_t sym;
  783         linker_symval_t symval;
  784         caddr_t address;
  785         size_t common_size = 0;
  786         int i;
  787 
  788         sx_assert(&kld_sx, SA_XLOCKED);
  789         KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n",
  790             file, name, deps));
  791 
  792         if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) {
  793                 LINKER_SYMBOL_VALUES(file, sym, &symval);
  794                 if (symval.value == 0)
  795                         /*
  796                          * For commons, first look them up in the
  797                          * dependencies and only allocate space if not found
  798                          * there.
  799                          */
  800                         common_size = symval.size;
  801                 else {
  802                         KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol"
  803                             ".value=%p\n", symval.value));
  804                         return (symval.value);
  805                 }
  806         }
  807         if (deps) {
  808                 for (i = 0; i < file->ndeps; i++) {
  809                         address = linker_file_lookup_symbol_internal(
  810                             file->deps[i], name, 0);
  811                         if (address) {
  812                                 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
  813                                     " deps value=%p\n", address));
  814                                 return (address);
  815                         }
  816                 }
  817         }
  818         if (common_size > 0) {
  819                 /*
  820                  * This is a common symbol which was not found in the
  821                  * dependencies.  We maintain a simple common symbol table in
  822                  * the file object.
  823                  */
  824                 struct common_symbol *cp;
  825 
  826                 STAILQ_FOREACH(cp, &file->common, link) {
  827                         if (strcmp(cp->name, name) == 0) {
  828                                 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
  829                                     " old common value=%p\n", cp->address));
  830                                 return (cp->address);
  831                         }
  832                 }
  833                 /*
  834                  * Round the symbol size up to align.
  835                  */
  836                 common_size = (common_size + sizeof(int) - 1) & -sizeof(int);
  837                 cp = malloc(sizeof(struct common_symbol)
  838                     + common_size + strlen(name) + 1, M_LINKER,
  839                     M_WAITOK | M_ZERO);
  840                 cp->address = (caddr_t)(cp + 1);
  841                 cp->name = cp->address + common_size;
  842                 strcpy(cp->name, name);
  843                 bzero(cp->address, common_size);
  844                 STAILQ_INSERT_TAIL(&file->common, cp, link);
  845 
  846                 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common"
  847                     " value=%p\n", cp->address));
  848                 return (cp->address);
  849         }
  850         KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
  851         return (0);
  852 }
  853 
  854 /*
  855  * Both DDB and stack(9) rely on the kernel linker to provide forward and
  856  * backward lookup of symbols.  However, DDB and sometimes stack(9) need to
  857  * do this in a lockfree manner.  We provide a set of internal helper
  858  * routines to perform these operations without locks, and then wrappers that
  859  * optionally lock.
  860  *
  861  * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB.
  862  */
  863 #ifdef DDB
  864 static int
  865 linker_debug_lookup(const char *symstr, c_linker_sym_t *sym)
  866 {
  867         linker_file_t lf;
  868 
  869         TAILQ_FOREACH(lf, &linker_files, link) {
  870                 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0)
  871                         return (0);
  872         }
  873         return (ENOENT);
  874 }
  875 #endif
  876 
  877 static int
  878 linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
  879 {
  880         linker_file_t lf;
  881         c_linker_sym_t best, es;
  882         u_long diff, bestdiff, off;
  883 
  884         best = 0;
  885         off = (uintptr_t)value;
  886         bestdiff = off;
  887         TAILQ_FOREACH(lf, &linker_files, link) {
  888                 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0)
  889                         continue;
  890                 if (es != 0 && diff < bestdiff) {
  891                         best = es;
  892                         bestdiff = diff;
  893                 }
  894                 if (bestdiff == 0)
  895                         break;
  896         }
  897         if (best) {
  898                 *sym = best;
  899                 *diffp = bestdiff;
  900                 return (0);
  901         } else {
  902                 *sym = 0;
  903                 *diffp = off;
  904                 return (ENOENT);
  905         }
  906 }
  907 
  908 static int
  909 linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
  910 {
  911         linker_file_t lf;
  912 
  913         TAILQ_FOREACH(lf, &linker_files, link) {
  914                 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0)
  915                         return (0);
  916         }
  917         return (ENOENT);
  918 }
  919 
  920 static int
  921 linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen,
  922     long *offset)
  923 {
  924         linker_symval_t symval;
  925         c_linker_sym_t sym;
  926         int error;
  927 
  928         *offset = 0;
  929         error = linker_debug_search_symbol(value, &sym, offset);
  930         if (error)
  931                 return (error);
  932         error = linker_debug_symbol_values(sym, &symval);
  933         if (error)
  934                 return (error);
  935         strlcpy(buf, symval.name, buflen);
  936         return (0);
  937 }
  938 
  939 /*
  940  * DDB Helpers.  DDB has to look across multiple files with their own symbol
  941  * tables and string tables.
  942  *
  943  * Note that we do not obey list locking protocols here.  We really don't need
  944  * DDB to hang because somebody's got the lock held.  We'll take the chance
  945  * that the files list is inconsistant instead.
  946  */
  947 #ifdef DDB
  948 int
  949 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
  950 {
  951 
  952         return (linker_debug_lookup(symstr, sym));
  953 }
  954 #endif
  955 
  956 int
  957 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
  958 {
  959 
  960         return (linker_debug_search_symbol(value, sym, diffp));
  961 }
  962 
  963 int
  964 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
  965 {
  966 
  967         return (linker_debug_symbol_values(sym, symval));
  968 }
  969 
  970 int
  971 linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen,
  972     long *offset)
  973 {
  974 
  975         return (linker_debug_search_symbol_name(value, buf, buflen, offset));
  976 }
  977 
  978 /*
  979  * stack(9) helper for non-debugging environemnts.  Unlike DDB helpers, we do
  980  * obey locking protocols, and offer a significantly less complex interface.
  981  */
  982 int
  983 linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
  984     long *offset)
  985 {
  986         int error;
  987 
  988         sx_xlock(&kld_sx);
  989         error = linker_debug_search_symbol_name(value, buf, buflen, offset);
  990         sx_xunlock(&kld_sx);
  991         return (error);
  992 }
  993 
  994 /*
  995  * Syscalls.
  996  */
  997 int
  998 kern_kldload(struct thread *td, const char *file, int *fileid)
  999 {
 1000         const char *kldname, *modname;
 1001         linker_file_t lf;
 1002         int error;
 1003 
 1004         if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
 1005                 return (error);
 1006 
 1007         if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0)
 1008                 return (error);
 1009 
 1010         /*
 1011          * It is possible that kldloaded module will attach a new ifnet,
 1012          * so vnet context must be set when this ocurs.
 1013          */
 1014         CURVNET_SET(TD_TO_VNET(td));
 1015 
 1016         /*
 1017          * If file does not contain a qualified name or any dot in it
 1018          * (kldname.ko, or kldname.ver.ko) treat it as an interface
 1019          * name.
 1020          */
 1021         if (strchr(file, '/') || strchr(file, '.')) {
 1022                 kldname = file;
 1023                 modname = NULL;
 1024         } else {
 1025                 kldname = NULL;
 1026                 modname = file;
 1027         }
 1028 
 1029         sx_xlock(&kld_sx);
 1030         error = linker_load_module(kldname, modname, NULL, NULL, &lf);
 1031         if (error) {
 1032                 sx_xunlock(&kld_sx);
 1033                 goto done;
 1034         }
 1035         lf->userrefs++;
 1036         if (fileid != NULL)
 1037                 *fileid = lf->id;
 1038         sx_xunlock(&kld_sx);
 1039 
 1040 done:
 1041         CURVNET_RESTORE();
 1042         return (error);
 1043 }
 1044 
 1045 int
 1046 sys_kldload(struct thread *td, struct kldload_args *uap)
 1047 {
 1048         char *pathname = NULL;
 1049         int error, fileid;
 1050 
 1051         td->td_retval[0] = -1;
 1052 
 1053         pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
 1054         error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL);
 1055         if (error == 0) {
 1056                 error = kern_kldload(td, pathname, &fileid);
 1057                 if (error == 0)
 1058                         td->td_retval[0] = fileid;
 1059         }
 1060         free(pathname, M_TEMP);
 1061         return (error);
 1062 }
 1063 
 1064 int
 1065 kern_kldunload(struct thread *td, int fileid, int flags)
 1066 {
 1067         linker_file_t lf;
 1068         int error = 0;
 1069 
 1070         if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
 1071                 return (error);
 1072 
 1073         if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0)
 1074                 return (error);
 1075 
 1076         CURVNET_SET(TD_TO_VNET(td));
 1077         sx_xlock(&kld_sx);
 1078         lf = linker_find_file_by_id(fileid);
 1079         if (lf) {
 1080                 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
 1081 
 1082                 if (lf->userrefs == 0) {
 1083                         /*
 1084                          * XXX: maybe LINKER_UNLOAD_FORCE should override ?
 1085                          */
 1086                         printf("kldunload: attempt to unload file that was"
 1087                             " loaded by the kernel\n");
 1088                         error = EBUSY;
 1089                 } else {
 1090                         lf->userrefs--;
 1091                         error = linker_file_unload(lf, flags);
 1092                         if (error)
 1093                                 lf->userrefs++;
 1094                 }
 1095         } else
 1096                 error = ENOENT;
 1097         sx_xunlock(&kld_sx);
 1098 
 1099         CURVNET_RESTORE();
 1100         return (error);
 1101 }
 1102 
 1103 int
 1104 sys_kldunload(struct thread *td, struct kldunload_args *uap)
 1105 {
 1106 
 1107         return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL));
 1108 }
 1109 
 1110 int
 1111 sys_kldunloadf(struct thread *td, struct kldunloadf_args *uap)
 1112 {
 1113 
 1114         if (uap->flags != LINKER_UNLOAD_NORMAL &&
 1115             uap->flags != LINKER_UNLOAD_FORCE)
 1116                 return (EINVAL);
 1117         return (kern_kldunload(td, uap->fileid, uap->flags));
 1118 }
 1119 
 1120 int
 1121 sys_kldfind(struct thread *td, struct kldfind_args *uap)
 1122 {
 1123         char *pathname;
 1124         const char *filename;
 1125         linker_file_t lf;
 1126         int error;
 1127 
 1128 #ifdef MAC
 1129         error = mac_kld_check_stat(td->td_ucred);
 1130         if (error)
 1131                 return (error);
 1132 #endif
 1133 
 1134         td->td_retval[0] = -1;
 1135 
 1136         pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
 1137         if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0)
 1138                 goto out;
 1139 
 1140         filename = linker_basename(pathname);
 1141         sx_xlock(&kld_sx);
 1142         lf = linker_find_file_by_name(filename);
 1143         if (lf)
 1144                 td->td_retval[0] = lf->id;
 1145         else
 1146                 error = ENOENT;
 1147         sx_xunlock(&kld_sx);
 1148 out:
 1149         free(pathname, M_TEMP);
 1150         return (error);
 1151 }
 1152 
 1153 int
 1154 sys_kldnext(struct thread *td, struct kldnext_args *uap)
 1155 {
 1156         linker_file_t lf;
 1157         int error = 0;
 1158 
 1159 #ifdef MAC
 1160         error = mac_kld_check_stat(td->td_ucred);
 1161         if (error)
 1162                 return (error);
 1163 #endif
 1164 
 1165         sx_xlock(&kld_sx);
 1166         if (uap->fileid == 0)
 1167                 lf = TAILQ_FIRST(&linker_files);
 1168         else {
 1169                 lf = linker_find_file_by_id(uap->fileid);
 1170                 if (lf == NULL) {
 1171                         error = ENOENT;
 1172                         goto out;
 1173                 }
 1174                 lf = TAILQ_NEXT(lf, link);
 1175         }
 1176 
 1177         /* Skip partially loaded files. */
 1178         while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED))
 1179                 lf = TAILQ_NEXT(lf, link);
 1180 
 1181         if (lf)
 1182                 td->td_retval[0] = lf->id;
 1183         else
 1184                 td->td_retval[0] = 0;
 1185 out:
 1186         sx_xunlock(&kld_sx);
 1187         return (error);
 1188 }
 1189 
 1190 int
 1191 sys_kldstat(struct thread *td, struct kldstat_args *uap)
 1192 {
 1193         struct kld_file_stat stat;
 1194         int error, version;
 1195 
 1196         /*
 1197          * Check the version of the user's structure.
 1198          */
 1199         if ((error = copyin(&uap->stat->version, &version, sizeof(version)))
 1200             != 0)
 1201                 return (error);
 1202         if (version != sizeof(struct kld_file_stat_1) &&
 1203             version != sizeof(struct kld_file_stat))
 1204                 return (EINVAL);
 1205 
 1206         error = kern_kldstat(td, uap->fileid, &stat);
 1207         if (error != 0)
 1208                 return (error);
 1209         return (copyout(&stat, uap->stat, version));
 1210 }
 1211 
 1212 int
 1213 kern_kldstat(struct thread *td, int fileid, struct kld_file_stat *stat)
 1214 {
 1215         linker_file_t lf;
 1216         int namelen;
 1217 #ifdef MAC
 1218         int error;
 1219 
 1220         error = mac_kld_check_stat(td->td_ucred);
 1221         if (error)
 1222                 return (error);
 1223 #endif
 1224 
 1225         sx_xlock(&kld_sx);
 1226         lf = linker_find_file_by_id(fileid);
 1227         if (lf == NULL) {
 1228                 sx_xunlock(&kld_sx);
 1229                 return (ENOENT);
 1230         }
 1231 
 1232         /* Version 1 fields: */
 1233         namelen = strlen(lf->filename) + 1;
 1234         if (namelen > MAXPATHLEN)
 1235                 namelen = MAXPATHLEN;
 1236         bcopy(lf->filename, &stat->name[0], namelen);
 1237         stat->refs = lf->refs;
 1238         stat->id = lf->id;
 1239         stat->address = lf->address;
 1240         stat->size = lf->size;
 1241         /* Version 2 fields: */
 1242         namelen = strlen(lf->pathname) + 1;
 1243         if (namelen > MAXPATHLEN)
 1244                 namelen = MAXPATHLEN;
 1245         bcopy(lf->pathname, &stat->pathname[0], namelen);
 1246         sx_xunlock(&kld_sx);
 1247 
 1248         td->td_retval[0] = 0;
 1249         return (0);
 1250 }
 1251 
 1252 int
 1253 sys_kldfirstmod(struct thread *td, struct kldfirstmod_args *uap)
 1254 {
 1255         linker_file_t lf;
 1256         module_t mp;
 1257         int error = 0;
 1258 
 1259 #ifdef MAC
 1260         error = mac_kld_check_stat(td->td_ucred);
 1261         if (error)
 1262                 return (error);
 1263 #endif
 1264 
 1265         sx_xlock(&kld_sx);
 1266         lf = linker_find_file_by_id(uap->fileid);
 1267         if (lf) {
 1268                 MOD_SLOCK;
 1269                 mp = TAILQ_FIRST(&lf->modules);
 1270                 if (mp != NULL)
 1271                         td->td_retval[0] = module_getid(mp);
 1272                 else
 1273                         td->td_retval[0] = 0;
 1274                 MOD_SUNLOCK;
 1275         } else
 1276                 error = ENOENT;
 1277         sx_xunlock(&kld_sx);
 1278         return (error);
 1279 }
 1280 
 1281 int
 1282 sys_kldsym(struct thread *td, struct kldsym_args *uap)
 1283 {
 1284         char *symstr = NULL;
 1285         c_linker_sym_t sym;
 1286         linker_symval_t symval;
 1287         linker_file_t lf;
 1288         struct kld_sym_lookup lookup;
 1289         int error = 0;
 1290 
 1291 #ifdef MAC
 1292         error = mac_kld_check_stat(td->td_ucred);
 1293         if (error)
 1294                 return (error);
 1295 #endif
 1296 
 1297         if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0)
 1298                 return (error);
 1299         if (lookup.version != sizeof(lookup) ||
 1300             uap->cmd != KLDSYM_LOOKUP)
 1301                 return (EINVAL);
 1302         symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
 1303         if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
 1304                 goto out;
 1305         sx_xlock(&kld_sx);
 1306         if (uap->fileid != 0) {
 1307                 lf = linker_find_file_by_id(uap->fileid);
 1308                 if (lf == NULL)
 1309                         error = ENOENT;
 1310                 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
 1311                     LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
 1312                         lookup.symvalue = (uintptr_t) symval.value;
 1313                         lookup.symsize = symval.size;
 1314                         error = copyout(&lookup, uap->data, sizeof(lookup));
 1315                 } else
 1316                         error = ENOENT;
 1317         } else {
 1318                 TAILQ_FOREACH(lf, &linker_files, link) {
 1319                         if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
 1320                             LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
 1321                                 lookup.symvalue = (uintptr_t)symval.value;
 1322                                 lookup.symsize = symval.size;
 1323                                 error = copyout(&lookup, uap->data,
 1324                                     sizeof(lookup));
 1325                                 break;
 1326                         }
 1327                 }
 1328                 if (lf == NULL)
 1329                         error = ENOENT;
 1330         }
 1331         sx_xunlock(&kld_sx);
 1332 out:
 1333         free(symstr, M_TEMP);
 1334         return (error);
 1335 }
 1336 
 1337 /*
 1338  * Preloaded module support
 1339  */
 1340 
 1341 static modlist_t
 1342 modlist_lookup(const char *name, int ver)
 1343 {
 1344         modlist_t mod;
 1345 
 1346         TAILQ_FOREACH(mod, &found_modules, link) {
 1347                 if (strcmp(mod->name, name) == 0 &&
 1348                     (ver == 0 || mod->version == ver))
 1349                         return (mod);
 1350         }
 1351         return (NULL);
 1352 }
 1353 
 1354 static modlist_t
 1355 modlist_lookup2(const char *name, struct mod_depend *verinfo)
 1356 {
 1357         modlist_t mod, bestmod;
 1358         int ver;
 1359 
 1360         if (verinfo == NULL)
 1361                 return (modlist_lookup(name, 0));
 1362         bestmod = NULL;
 1363         TAILQ_FOREACH(mod, &found_modules, link) {
 1364                 if (strcmp(mod->name, name) != 0)
 1365                         continue;
 1366                 ver = mod->version;
 1367                 if (ver == verinfo->md_ver_preferred)
 1368                         return (mod);
 1369                 if (ver >= verinfo->md_ver_minimum &&
 1370                     ver <= verinfo->md_ver_maximum &&
 1371                     (bestmod == NULL || ver > bestmod->version))
 1372                         bestmod = mod;
 1373         }
 1374         return (bestmod);
 1375 }
 1376 
 1377 static modlist_t
 1378 modlist_newmodule(const char *modname, int version, linker_file_t container)
 1379 {
 1380         modlist_t mod;
 1381 
 1382         mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO);
 1383         if (mod == NULL)
 1384                 panic("no memory for module list");
 1385         mod->container = container;
 1386         mod->name = modname;
 1387         mod->version = version;
 1388         TAILQ_INSERT_TAIL(&found_modules, mod, link);
 1389         return (mod);
 1390 }
 1391 
 1392 static void
 1393 linker_addmodules(linker_file_t lf, struct mod_metadata **start,
 1394     struct mod_metadata **stop, int preload)
 1395 {
 1396         struct mod_metadata *mp, **mdp;
 1397         const char *modname;
 1398         int ver;
 1399 
 1400         for (mdp = start; mdp < stop; mdp++) {
 1401                 mp = *mdp;
 1402                 if (mp->md_type != MDT_VERSION)
 1403                         continue;
 1404                 modname = mp->md_cval;
 1405                 ver = ((struct mod_version *)mp->md_data)->mv_version;
 1406                 if (modlist_lookup(modname, ver) != NULL) {
 1407                         printf("module %s already present!\n", modname);
 1408                         /* XXX what can we do? this is a build error. :-( */
 1409                         continue;
 1410                 }
 1411                 modlist_newmodule(modname, ver, lf);
 1412         }
 1413 }
 1414 
 1415 static void
 1416 linker_preload(void *arg)
 1417 {
 1418         caddr_t modptr;
 1419         const char *modname, *nmodname;
 1420         char *modtype;
 1421         linker_file_t lf, nlf;
 1422         linker_class_t lc;
 1423         int error;
 1424         linker_file_list_t loaded_files;
 1425         linker_file_list_t depended_files;
 1426         struct mod_metadata *mp, *nmp;
 1427         struct mod_metadata **start, **stop, **mdp, **nmdp;
 1428         struct mod_depend *verinfo;
 1429         int nver;
 1430         int resolves;
 1431         modlist_t mod;
 1432         struct sysinit **si_start, **si_stop;
 1433 
 1434         TAILQ_INIT(&loaded_files);
 1435         TAILQ_INIT(&depended_files);
 1436         TAILQ_INIT(&found_modules);
 1437         error = 0;
 1438 
 1439         modptr = NULL;
 1440         sx_xlock(&kld_sx);
 1441         while ((modptr = preload_search_next_name(modptr)) != NULL) {
 1442                 modname = (char *)preload_search_info(modptr, MODINFO_NAME);
 1443                 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
 1444                 if (modname == NULL) {
 1445                         printf("Preloaded module at %p does not have a"
 1446                             " name!\n", modptr);
 1447                         continue;
 1448                 }
 1449                 if (modtype == NULL) {
 1450                         printf("Preloaded module at %p does not have a type!\n",
 1451                             modptr);
 1452                         continue;
 1453                 }
 1454                 if (bootverbose)
 1455                         printf("Preloaded %s \"%s\" at %p.\n", modtype, modname,
 1456                             modptr);
 1457                 lf = NULL;
 1458                 TAILQ_FOREACH(lc, &classes, link) {
 1459                         error = LINKER_LINK_PRELOAD(lc, modname, &lf);
 1460                         if (!error)
 1461                                 break;
 1462                         lf = NULL;
 1463                 }
 1464                 if (lf)
 1465                         TAILQ_INSERT_TAIL(&loaded_files, lf, loaded);
 1466         }
 1467 
 1468         /*
 1469          * First get a list of stuff in the kernel.
 1470          */
 1471         if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start,
 1472             &stop, NULL) == 0)
 1473                 linker_addmodules(linker_kernel_file, start, stop, 1);
 1474 
 1475         /*
 1476          * This is a once-off kinky bubble sort to resolve relocation
 1477          * dependency requirements.
 1478          */
 1479 restart:
 1480         TAILQ_FOREACH(lf, &loaded_files, loaded) {
 1481                 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
 1482                     &stop, NULL);
 1483                 /*
 1484                  * First, look to see if we would successfully link with this
 1485                  * stuff.
 1486                  */
 1487                 resolves = 1;   /* unless we know otherwise */
 1488                 if (!error) {
 1489                         for (mdp = start; mdp < stop; mdp++) {
 1490                                 mp = *mdp;
 1491                                 if (mp->md_type != MDT_DEPEND)
 1492                                         continue;
 1493                                 modname = mp->md_cval;
 1494                                 verinfo = mp->md_data;
 1495                                 for (nmdp = start; nmdp < stop; nmdp++) {
 1496                                         nmp = *nmdp;
 1497                                         if (nmp->md_type != MDT_VERSION)
 1498                                                 continue;
 1499                                         nmodname = nmp->md_cval;
 1500                                         if (strcmp(modname, nmodname) == 0)
 1501                                                 break;
 1502                                 }
 1503                                 if (nmdp < stop)   /* it's a self reference */
 1504                                         continue;
 1505 
 1506                                 /*
 1507                                  * ok, the module isn't here yet, we
 1508                                  * are not finished
 1509                                  */
 1510                                 if (modlist_lookup2(modname, verinfo) == NULL)
 1511                                         resolves = 0;
 1512                         }
 1513                 }
 1514                 /*
 1515                  * OK, if we found our modules, we can link.  So, "provide"
 1516                  * the modules inside and add it to the end of the link order
 1517                  * list.
 1518                  */
 1519                 if (resolves) {
 1520                         if (!error) {
 1521                                 for (mdp = start; mdp < stop; mdp++) {
 1522                                         mp = *mdp;
 1523                                         if (mp->md_type != MDT_VERSION)
 1524                                                 continue;
 1525                                         modname = mp->md_cval;
 1526                                         nver = ((struct mod_version *)
 1527                                             mp->md_data)->mv_version;
 1528                                         if (modlist_lookup(modname,
 1529                                             nver) != NULL) {
 1530                                                 printf("module %s already"
 1531                                                     " present!\n", modname);
 1532                                                 TAILQ_REMOVE(&loaded_files,
 1533                                                     lf, loaded);
 1534                                                 linker_file_unload(lf,
 1535                                                     LINKER_UNLOAD_FORCE);
 1536                                                 /* we changed tailq next ptr */
 1537                                                 goto restart;
 1538                                         }
 1539                                         modlist_newmodule(modname, nver, lf);
 1540                                 }
 1541                         }
 1542                         TAILQ_REMOVE(&loaded_files, lf, loaded);
 1543                         TAILQ_INSERT_TAIL(&depended_files, lf, loaded);
 1544                         /*
 1545                          * Since we provided modules, we need to restart the
 1546                          * sort so that the previous files that depend on us
 1547                          * have a chance. Also, we've busted the tailq next
 1548                          * pointer with the REMOVE.
 1549                          */
 1550                         goto restart;
 1551                 }
 1552         }
 1553 
 1554         /*
 1555          * At this point, we check to see what could not be resolved..
 1556          */
 1557         while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) {
 1558                 TAILQ_REMOVE(&loaded_files, lf, loaded);
 1559                 printf("KLD file %s is missing dependencies\n", lf->filename);
 1560                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 1561         }
 1562 
 1563         /*
 1564          * We made it. Finish off the linking in the order we determined.
 1565          */
 1566         TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) {
 1567                 if (linker_kernel_file) {
 1568                         linker_kernel_file->refs++;
 1569                         error = linker_file_add_dependency(lf,
 1570                             linker_kernel_file);
 1571                         if (error)
 1572                                 panic("cannot add dependency");
 1573                 }
 1574                 lf->userrefs++; /* so we can (try to) kldunload it */
 1575                 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
 1576                     &stop, NULL);
 1577                 if (!error) {
 1578                         for (mdp = start; mdp < stop; mdp++) {
 1579                                 mp = *mdp;
 1580                                 if (mp->md_type != MDT_DEPEND)
 1581                                         continue;
 1582                                 modname = mp->md_cval;
 1583                                 verinfo = mp->md_data;
 1584                                 mod = modlist_lookup2(modname, verinfo);
 1585                                 if (mod == NULL) {
 1586                                         printf("KLD file %s - cannot find "
 1587                                             "dependency \"%s\"\n",
 1588                                             lf->filename, modname);
 1589                                         goto fail;
 1590                                 }
 1591                                 /* Don't count self-dependencies */
 1592                                 if (lf == mod->container)
 1593                                         continue;
 1594                                 mod->container->refs++;
 1595                                 error = linker_file_add_dependency(lf,
 1596                                     mod->container);
 1597                                 if (error)
 1598                                         panic("cannot add dependency");
 1599                         }
 1600                 }
 1601                 /*
 1602                  * Now do relocation etc using the symbol search paths
 1603                  * established by the dependencies
 1604                  */
 1605                 error = LINKER_LINK_PRELOAD_FINISH(lf);
 1606                 if (error) {
 1607                         printf("KLD file %s - could not finalize loading\n",
 1608                             lf->filename);
 1609                         goto fail;
 1610                 }
 1611                 linker_file_register_modules(lf);
 1612                 if (linker_file_lookup_set(lf, "sysinit_set", &si_start,
 1613                     &si_stop, NULL) == 0)
 1614                         sysinit_add(si_start, si_stop);
 1615                 linker_file_register_sysctls(lf);
 1616                 lf->flags |= LINKER_FILE_LINKED;
 1617                 continue;
 1618 fail:
 1619                 TAILQ_REMOVE(&depended_files, lf, loaded);
 1620                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 1621         }
 1622         sx_xunlock(&kld_sx);
 1623         /* woohoo! we made it! */
 1624 }
 1625 
 1626 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0);
 1627 
 1628 /*
 1629  * Search for a not-loaded module by name.
 1630  *
 1631  * Modules may be found in the following locations:
 1632  *
 1633  * - preloaded (result is just the module name) - on disk (result is full path
 1634  * to module)
 1635  *
 1636  * If the module name is qualified in any way (contains path, etc.) the we
 1637  * simply return a copy of it.
 1638  *
 1639  * The search path can be manipulated via sysctl.  Note that we use the ';'
 1640  * character as a separator to be consistent with the bootloader.
 1641  */
 1642 
 1643 static char linker_hintfile[] = "linker.hints";
 1644 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules";
 1645 
 1646 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path,
 1647     sizeof(linker_path), "module load search path");
 1648 
 1649 TUNABLE_STR("module_path", linker_path, sizeof(linker_path));
 1650 
 1651 static char *linker_ext_list[] = {
 1652         "",
 1653         ".ko",
 1654         NULL
 1655 };
 1656 
 1657 /*
 1658  * Check if file actually exists either with or without extension listed in
 1659  * the linker_ext_list. (probably should be generic for the rest of the
 1660  * kernel)
 1661  */
 1662 static char *
 1663 linker_lookup_file(const char *path, int pathlen, const char *name,
 1664     int namelen, struct vattr *vap)
 1665 {
 1666         struct nameidata nd;
 1667         struct thread *td = curthread;  /* XXX */
 1668         char *result, **cpp, *sep;
 1669         int error, len, extlen, reclen, flags;
 1670         enum vtype type;
 1671 
 1672         extlen = 0;
 1673         for (cpp = linker_ext_list; *cpp; cpp++) {
 1674                 len = strlen(*cpp);
 1675                 if (len > extlen)
 1676                         extlen = len;
 1677         }
 1678         extlen++;               /* trailing '\0' */
 1679         sep = (path[pathlen - 1] != '/') ? "/" : "";
 1680 
 1681         reclen = pathlen + strlen(sep) + namelen + extlen + 1;
 1682         result = malloc(reclen, M_LINKER, M_WAITOK);
 1683         for (cpp = linker_ext_list; *cpp; cpp++) {
 1684                 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep,
 1685                     namelen, name, *cpp);
 1686                 /*
 1687                  * Attempt to open the file, and return the path if
 1688                  * we succeed and it's a regular file.
 1689                  */
 1690                 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, result, td);
 1691                 flags = FREAD;
 1692                 error = vn_open(&nd, &flags, 0, NULL);
 1693                 if (error == 0) {
 1694                         NDFREE(&nd, NDF_ONLY_PNBUF);
 1695                         type = nd.ni_vp->v_type;
 1696                         if (vap)
 1697                                 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred);
 1698                         VOP_UNLOCK(nd.ni_vp, 0);
 1699                         vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
 1700                         if (type == VREG)
 1701                                 return (result);
 1702                 }
 1703         }
 1704         free(result, M_LINKER);
 1705         return (NULL);
 1706 }
 1707 
 1708 #define INT_ALIGN(base, ptr)    ptr =                                   \
 1709         (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1))
 1710 
 1711 /*
 1712  * Lookup KLD which contains requested module in the "linker.hints" file. If
 1713  * version specification is available, then try to find the best KLD.
 1714  * Otherwise just find the latest one.
 1715  */
 1716 static char *
 1717 linker_hints_lookup(const char *path, int pathlen, const char *modname,
 1718     int modnamelen, struct mod_depend *verinfo)
 1719 {
 1720         struct thread *td = curthread;  /* XXX */
 1721         struct ucred *cred = td ? td->td_ucred : NULL;
 1722         struct nameidata nd;
 1723         struct vattr vattr, mattr;
 1724         u_char *hints = NULL;
 1725         u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep;
 1726         int error, ival, bestver, *intp, found, flags, clen, blen;
 1727         ssize_t reclen;
 1728 
 1729         result = NULL;
 1730         bestver = found = 0;
 1731 
 1732         sep = (path[pathlen - 1] != '/') ? "/" : "";
 1733         reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen +
 1734             strlen(sep) + 1;
 1735         pathbuf = malloc(reclen, M_LINKER, M_WAITOK);
 1736         snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep,
 1737             linker_hintfile);
 1738 
 1739         NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, pathbuf, td);
 1740         flags = FREAD;
 1741         error = vn_open(&nd, &flags, 0, NULL);
 1742         if (error)
 1743                 goto bad;
 1744         NDFREE(&nd, NDF_ONLY_PNBUF);
 1745         if (nd.ni_vp->v_type != VREG)
 1746                 goto bad;
 1747         best = cp = NULL;
 1748         error = VOP_GETATTR(nd.ni_vp, &vattr, cred);
 1749         if (error)
 1750                 goto bad;
 1751         /*
 1752          * XXX: we need to limit this number to some reasonable value
 1753          */
 1754         if (vattr.va_size > 100 * 1024) {
 1755                 printf("hints file too large %ld\n", (long)vattr.va_size);
 1756                 goto bad;
 1757         }
 1758         hints = malloc(vattr.va_size, M_TEMP, M_WAITOK);
 1759         if (hints == NULL)
 1760                 goto bad;
 1761         error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0,
 1762             UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td);
 1763         if (error)
 1764                 goto bad;
 1765         VOP_UNLOCK(nd.ni_vp, 0);
 1766         vn_close(nd.ni_vp, FREAD, cred, td);
 1767         nd.ni_vp = NULL;
 1768         if (reclen != 0) {
 1769                 printf("can't read %zd\n", reclen);
 1770                 goto bad;
 1771         }
 1772         intp = (int *)hints;
 1773         ival = *intp++;
 1774         if (ival != LINKER_HINTS_VERSION) {
 1775                 printf("hints file version mismatch %d\n", ival);
 1776                 goto bad;
 1777         }
 1778         bufend = hints + vattr.va_size;
 1779         recptr = (u_char *)intp;
 1780         clen = blen = 0;
 1781         while (recptr < bufend && !found) {
 1782                 intp = (int *)recptr;
 1783                 reclen = *intp++;
 1784                 ival = *intp++;
 1785                 cp = (char *)intp;
 1786                 switch (ival) {
 1787                 case MDT_VERSION:
 1788                         clen = *cp++;
 1789                         if (clen != modnamelen || bcmp(cp, modname, clen) != 0)
 1790                                 break;
 1791                         cp += clen;
 1792                         INT_ALIGN(hints, cp);
 1793                         ival = *(int *)cp;
 1794                         cp += sizeof(int);
 1795                         clen = *cp++;
 1796                         if (verinfo == NULL ||
 1797                             ival == verinfo->md_ver_preferred) {
 1798                                 found = 1;
 1799                                 break;
 1800                         }
 1801                         if (ival >= verinfo->md_ver_minimum &&
 1802                             ival <= verinfo->md_ver_maximum &&
 1803                             ival > bestver) {
 1804                                 bestver = ival;
 1805                                 best = cp;
 1806                                 blen = clen;
 1807                         }
 1808                         break;
 1809                 default:
 1810                         break;
 1811                 }
 1812                 recptr += reclen + sizeof(int);
 1813         }
 1814         /*
 1815          * Finally check if KLD is in the place
 1816          */
 1817         if (found)
 1818                 result = linker_lookup_file(path, pathlen, cp, clen, &mattr);
 1819         else if (best)
 1820                 result = linker_lookup_file(path, pathlen, best, blen, &mattr);
 1821 
 1822         /*
 1823          * KLD is newer than hints file. What we should do now?
 1824          */
 1825         if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >))
 1826                 printf("warning: KLD '%s' is newer than the linker.hints"
 1827                     " file\n", result);
 1828 bad:
 1829         free(pathbuf, M_LINKER);
 1830         if (hints)
 1831                 free(hints, M_TEMP);
 1832         if (nd.ni_vp != NULL) {
 1833                 VOP_UNLOCK(nd.ni_vp, 0);
 1834                 vn_close(nd.ni_vp, FREAD, cred, td);
 1835         }
 1836         /*
 1837          * If nothing found or hints is absent - fallback to the old
 1838          * way by using "kldname[.ko]" as module name.
 1839          */
 1840         if (!found && !bestver && result == NULL)
 1841                 result = linker_lookup_file(path, pathlen, modname,
 1842                     modnamelen, NULL);
 1843         return (result);
 1844 }
 1845 
 1846 /*
 1847  * Lookup KLD which contains requested module in the all directories.
 1848  */
 1849 static char *
 1850 linker_search_module(const char *modname, int modnamelen,
 1851     struct mod_depend *verinfo)
 1852 {
 1853         char *cp, *ep, *result;
 1854 
 1855         /*
 1856          * traverse the linker path
 1857          */
 1858         for (cp = linker_path; *cp; cp = ep + 1) {
 1859                 /* find the end of this component */
 1860                 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++);
 1861                 result = linker_hints_lookup(cp, ep - cp, modname,
 1862                     modnamelen, verinfo);
 1863                 if (result != NULL)
 1864                         return (result);
 1865                 if (*ep == 0)
 1866                         break;
 1867         }
 1868         return (NULL);
 1869 }
 1870 
 1871 /*
 1872  * Search for module in all directories listed in the linker_path.
 1873  */
 1874 static char *
 1875 linker_search_kld(const char *name)
 1876 {
 1877         char *cp, *ep, *result;
 1878         int len;
 1879 
 1880         /* qualified at all? */
 1881         if (strchr(name, '/'))
 1882                 return (strdup(name, M_LINKER));
 1883 
 1884         /* traverse the linker path */
 1885         len = strlen(name);
 1886         for (ep = linker_path; *ep; ep++) {
 1887                 cp = ep;
 1888                 /* find the end of this component */
 1889                 for (; *ep != 0 && *ep != ';'; ep++);
 1890                 result = linker_lookup_file(cp, ep - cp, name, len, NULL);
 1891                 if (result != NULL)
 1892                         return (result);
 1893         }
 1894         return (NULL);
 1895 }
 1896 
 1897 static const char *
 1898 linker_basename(const char *path)
 1899 {
 1900         const char *filename;
 1901 
 1902         filename = strrchr(path, '/');
 1903         if (filename == NULL)
 1904                 return path;
 1905         if (filename[1])
 1906                 filename++;
 1907         return (filename);
 1908 }
 1909 
 1910 #ifdef HWPMC_HOOKS
 1911 /*
 1912  * Inform hwpmc about the set of kernel modules currently loaded.
 1913  */
 1914 void *
 1915 linker_hwpmc_list_objects(void)
 1916 {
 1917         linker_file_t lf;
 1918         struct pmckern_map_in *kobase;
 1919         int i, nmappings;
 1920 
 1921         nmappings = 0;
 1922         sx_slock(&kld_sx);
 1923         TAILQ_FOREACH(lf, &linker_files, link)
 1924                 nmappings++;
 1925 
 1926         /* Allocate nmappings + 1 entries. */
 1927         kobase = malloc((nmappings + 1) * sizeof(struct pmckern_map_in),
 1928             M_LINKER, M_WAITOK | M_ZERO);
 1929         i = 0;
 1930         TAILQ_FOREACH(lf, &linker_files, link) {
 1931 
 1932                 /* Save the info for this linker file. */
 1933                 kobase[i].pm_file = lf->filename;
 1934                 kobase[i].pm_address = (uintptr_t)lf->address;
 1935                 i++;
 1936         }
 1937         sx_sunlock(&kld_sx);
 1938 
 1939         KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?"));
 1940 
 1941         /* The last entry of the malloced area comprises of all zeros. */
 1942         KASSERT(kobase[i].pm_file == NULL,
 1943             ("linker_hwpmc_list_objects: last object not NULL"));
 1944 
 1945         return ((void *)kobase);
 1946 }
 1947 #endif
 1948 
 1949 /*
 1950  * Find a file which contains given module and load it, if "parent" is not
 1951  * NULL, register a reference to it.
 1952  */
 1953 static int
 1954 linker_load_module(const char *kldname, const char *modname,
 1955     struct linker_file *parent, struct mod_depend *verinfo,
 1956     struct linker_file **lfpp)
 1957 {
 1958         linker_file_t lfdep;
 1959         const char *filename;
 1960         char *pathname;
 1961         int error;
 1962 
 1963         sx_assert(&kld_sx, SA_XLOCKED);
 1964         if (modname == NULL) {
 1965                 /*
 1966                  * We have to load KLD
 1967                  */
 1968                 KASSERT(verinfo == NULL, ("linker_load_module: verinfo"
 1969                     " is not NULL"));
 1970                 pathname = linker_search_kld(kldname);
 1971         } else {
 1972                 if (modlist_lookup2(modname, verinfo) != NULL)
 1973                         return (EEXIST);
 1974                 if (kldname != NULL)
 1975                         pathname = strdup(kldname, M_LINKER);
 1976                 else if (rootvnode == NULL)
 1977                         pathname = NULL;
 1978                 else
 1979                         /*
 1980                          * Need to find a KLD with required module
 1981                          */
 1982                         pathname = linker_search_module(modname,
 1983                             strlen(modname), verinfo);
 1984         }
 1985         if (pathname == NULL)
 1986                 return (ENOENT);
 1987 
 1988         /*
 1989          * Can't load more than one file with the same basename XXX:
 1990          * Actually it should be possible to have multiple KLDs with
 1991          * the same basename but different path because they can
 1992          * provide different versions of the same modules.
 1993          */
 1994         filename = linker_basename(pathname);
 1995         if (linker_find_file_by_name(filename))
 1996                 error = EEXIST;
 1997         else do {
 1998                 error = linker_load_file(pathname, &lfdep);
 1999                 if (error)
 2000                         break;
 2001                 if (modname && verinfo &&
 2002                     modlist_lookup2(modname, verinfo) == NULL) {
 2003                         linker_file_unload(lfdep, LINKER_UNLOAD_FORCE);
 2004                         error = ENOENT;
 2005                         break;
 2006                 }
 2007                 if (parent) {
 2008                         error = linker_file_add_dependency(parent, lfdep);
 2009                         if (error)
 2010                                 break;
 2011                 }
 2012                 if (lfpp)
 2013                         *lfpp = lfdep;
 2014         } while (0);
 2015         free(pathname, M_LINKER);
 2016         return (error);
 2017 }
 2018 
 2019 /*
 2020  * This routine is responsible for finding dependencies of userland initiated
 2021  * kldload(2)'s of files.
 2022  */
 2023 int
 2024 linker_load_dependencies(linker_file_t lf)
 2025 {
 2026         linker_file_t lfdep;
 2027         struct mod_metadata **start, **stop, **mdp, **nmdp;
 2028         struct mod_metadata *mp, *nmp;
 2029         struct mod_depend *verinfo;
 2030         modlist_t mod;
 2031         const char *modname, *nmodname;
 2032         int ver, error = 0, count;
 2033 
 2034         /*
 2035          * All files are dependant on /kernel.
 2036          */
 2037         sx_assert(&kld_sx, SA_XLOCKED);
 2038         if (linker_kernel_file) {
 2039                 linker_kernel_file->refs++;
 2040                 error = linker_file_add_dependency(lf, linker_kernel_file);
 2041                 if (error)
 2042                         return (error);
 2043         }
 2044         if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop,
 2045             &count) != 0)
 2046                 return (0);
 2047         for (mdp = start; mdp < stop; mdp++) {
 2048                 mp = *mdp;
 2049                 if (mp->md_type != MDT_VERSION)
 2050                         continue;
 2051                 modname = mp->md_cval;
 2052                 ver = ((struct mod_version *)mp->md_data)->mv_version;
 2053                 mod = modlist_lookup(modname, ver);
 2054                 if (mod != NULL) {
 2055                         printf("interface %s.%d already present in the KLD"
 2056                             " '%s'!\n", modname, ver,
 2057                             mod->container->filename);
 2058                         return (EEXIST);
 2059                 }
 2060         }
 2061 
 2062         for (mdp = start; mdp < stop; mdp++) {
 2063                 mp = *mdp;
 2064                 if (mp->md_type != MDT_DEPEND)
 2065                         continue;
 2066                 modname = mp->md_cval;
 2067                 verinfo = mp->md_data;
 2068                 nmodname = NULL;
 2069                 for (nmdp = start; nmdp < stop; nmdp++) {
 2070                         nmp = *nmdp;
 2071                         if (nmp->md_type != MDT_VERSION)
 2072                                 continue;
 2073                         nmodname = nmp->md_cval;
 2074                         if (strcmp(modname, nmodname) == 0)
 2075                                 break;
 2076                 }
 2077                 if (nmdp < stop)/* early exit, it's a self reference */
 2078                         continue;
 2079                 mod = modlist_lookup2(modname, verinfo);
 2080                 if (mod) {      /* woohoo, it's loaded already */
 2081                         lfdep = mod->container;
 2082                         lfdep->refs++;
 2083                         error = linker_file_add_dependency(lf, lfdep);
 2084                         if (error)
 2085                                 break;
 2086                         continue;
 2087                 }
 2088                 error = linker_load_module(NULL, modname, lf, verinfo, NULL);
 2089                 if (error) {
 2090                         printf("KLD %s: depends on %s - not available or"
 2091                             " version mismatch\n", lf->filename, modname);
 2092                         break;
 2093                 }
 2094         }
 2095 
 2096         if (error)
 2097                 return (error);
 2098         linker_addmodules(lf, start, stop, 0);
 2099         return (error);
 2100 }
 2101 
 2102 static int
 2103 sysctl_kern_function_list_iterate(const char *name, void *opaque)
 2104 {
 2105         struct sysctl_req *req;
 2106 
 2107         req = opaque;
 2108         return (SYSCTL_OUT(req, name, strlen(name) + 1));
 2109 }
 2110 
 2111 /*
 2112  * Export a nul-separated, double-nul-terminated list of all function names
 2113  * in the kernel.
 2114  */
 2115 static int
 2116 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS)
 2117 {
 2118         linker_file_t lf;
 2119         int error;
 2120 
 2121 #ifdef MAC
 2122         error = mac_kld_check_stat(req->td->td_ucred);
 2123         if (error)
 2124                 return (error);
 2125 #endif
 2126         error = sysctl_wire_old_buffer(req, 0);
 2127         if (error != 0)
 2128                 return (error);
 2129         sx_xlock(&kld_sx);
 2130         TAILQ_FOREACH(lf, &linker_files, link) {
 2131                 error = LINKER_EACH_FUNCTION_NAME(lf,
 2132                     sysctl_kern_function_list_iterate, req);
 2133                 if (error) {
 2134                         sx_xunlock(&kld_sx);
 2135                         return (error);
 2136                 }
 2137         }
 2138         sx_xunlock(&kld_sx);
 2139         return (SYSCTL_OUT(req, "", 1));
 2140 }
 2141 
 2142 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLTYPE_OPAQUE | CTLFLAG_RD,
 2143     NULL, 0, sysctl_kern_function_list, "", "kernel function list");

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