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/8.4/sys/kern/kern_linker.c 235621 2012-05-18 18:53:28Z jhb $");
   29 
   30 #include "opt_ddb.h"
   31 #include "opt_hwpmc_hooks.h"
   32 
   33 #include <sys/param.h>
   34 #include <sys/kernel.h>
   35 #include <sys/systm.h>
   36 #include <sys/malloc.h>
   37 #include <sys/sysproto.h>
   38 #include <sys/sysent.h>
   39 #include <sys/priv.h>
   40 #include <sys/proc.h>
   41 #include <sys/lock.h>
   42 #include <sys/mutex.h>
   43 #include <sys/sx.h>
   44 #include <sys/module.h>
   45 #include <sys/mount.h>
   46 #include <sys/linker.h>
   47 #include <sys/fcntl.h>
   48 #include <sys/jail.h>
   49 #include <sys/libkern.h>
   50 #include <sys/namei.h>
   51 #include <sys/vnode.h>
   52 #include <sys/syscallsubr.h>
   53 #include <sys/sysctl.h>
   54 
   55 #include <net/vnet.h>
   56 
   57 #include <security/mac/mac_framework.h>
   58 
   59 #include "linker_if.h"
   60 
   61 #ifdef HWPMC_HOOKS
   62 #include <sys/pmckern.h>
   63 #endif
   64 
   65 #ifdef KLD_DEBUG
   66 int kld_debug = 0;
   67 #endif
   68 
   69 #define KLD_LOCK()              sx_xlock(&kld_sx)
   70 #define KLD_UNLOCK()            sx_xunlock(&kld_sx)
   71 #define KLD_DOWNGRADE()         sx_downgrade(&kld_sx)
   72 #define KLD_LOCK_READ()         sx_slock(&kld_sx)
   73 #define KLD_UNLOCK_READ()       sx_sunlock(&kld_sx)
   74 #define KLD_LOCKED()            sx_xlocked(&kld_sx)
   75 #define KLD_LOCK_ASSERT() do {                                          \
   76         if (!cold)                                                      \
   77                 sx_assert(&kld_sx, SX_XLOCKED);                         \
   78 } while (0)
   79 
   80 /*
   81  * static char *linker_search_path(const char *name, struct mod_depend
   82  * *verinfo);
   83  */
   84 static const char       *linker_basename(const char *path);
   85 
   86 /*
   87  * Find a currently loaded file given its filename.
   88  */
   89 static linker_file_t linker_find_file_by_name(const char* _filename);
   90 
   91 /*
   92  * Find a currently loaded file given its file id.
   93  */
   94 static linker_file_t linker_find_file_by_id(int _fileid);
   95 
   96 /* Metadata from the static kernel */
   97 SET_DECLARE(modmetadata_set, struct mod_metadata);
   98 
   99 MALLOC_DEFINE(M_LINKER, "linker", "kernel linker");
  100 
  101 linker_file_t linker_kernel_file;
  102 
  103 static struct sx kld_sx;        /* kernel linker lock */
  104 
  105 /*
  106  * Load counter used by clients to determine if a linker file has been
  107  * re-loaded. This counter is incremented for each file load.
  108  */
  109 static int loadcnt;
  110 
  111 static linker_class_list_t classes;
  112 static linker_file_list_t linker_files;
  113 static int next_file_id = 1;
  114 static int linker_no_more_classes = 0;
  115 
  116 #define LINKER_GET_NEXT_FILE_ID(a) do {                                 \
  117         linker_file_t lftmp;                                            \
  118                                                                         \
  119         KLD_LOCK_ASSERT();                                              \
  120 retry:                                                                  \
  121         TAILQ_FOREACH(lftmp, &linker_files, link) {                     \
  122                 if (next_file_id == lftmp->id) {                        \
  123                         next_file_id++;                                 \
  124                         goto retry;                                     \
  125                 }                                                       \
  126         }                                                               \
  127         (a) = next_file_id;                                             \
  128 } while(0)
  129 
  130 
  131 /* XXX wrong name; we're looking at version provision tags here, not modules */
  132 typedef TAILQ_HEAD(, modlist) modlisthead_t;
  133 struct modlist {
  134         TAILQ_ENTRY(modlist) link;      /* chain together all modules */
  135         linker_file_t   container;
  136         const char      *name;
  137         int             version;
  138 };
  139 typedef struct modlist *modlist_t;
  140 static modlisthead_t found_modules;
  141 
  142 static int      linker_file_add_dependency(linker_file_t file,
  143                     linker_file_t dep);
  144 static caddr_t  linker_file_lookup_symbol_internal(linker_file_t file,
  145                     const char* name, int deps);
  146 static int      linker_load_module(const char *kldname,
  147                     const char *modname, struct linker_file *parent,
  148                     struct mod_depend *verinfo, struct linker_file **lfpp);
  149 static modlist_t modlist_lookup2(const char *name, struct mod_depend *verinfo);
  150 
  151 static char *
  152 linker_strdup(const char *str)
  153 {
  154         char *result;
  155 
  156         if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL)
  157                 strcpy(result, str);
  158         return (result);
  159 }
  160 
  161 static void
  162 linker_init(void *arg)
  163 {
  164 
  165         sx_init(&kld_sx, "kernel linker");
  166         TAILQ_INIT(&classes);
  167         TAILQ_INIT(&linker_files);
  168 }
  169 
  170 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0);
  171 
  172 static void
  173 linker_stop_class_add(void *arg)
  174 {
  175 
  176         linker_no_more_classes = 1;
  177 }
  178 
  179 SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL);
  180 
  181 int
  182 linker_add_class(linker_class_t lc)
  183 {
  184 
  185         /*
  186          * We disallow any class registration past SI_ORDER_ANY
  187          * of SI_SUB_KLD.  We bump the reference count to keep the
  188          * ops from being freed.
  189          */
  190         if (linker_no_more_classes == 1)
  191                 return (EPERM);
  192         kobj_class_compile((kobj_class_t) lc);
  193         ((kobj_class_t)lc)->refs++;     /* XXX: kobj_mtx */
  194         TAILQ_INSERT_TAIL(&classes, lc, link);
  195         return (0);
  196 }
  197 
  198 static void
  199 linker_file_sysinit(linker_file_t lf)
  200 {
  201         struct sysinit **start, **stop, **sipp, **xipp, *save;
  202 
  203         KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n",
  204             lf->filename));
  205 
  206         if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0)
  207                 return;
  208         /*
  209          * Perform a bubble sort of the system initialization objects by
  210          * their subsystem (primary key) and order (secondary key).
  211          *
  212          * Since some things care about execution order, this is the operation
  213          * which ensures continued function.
  214          */
  215         for (sipp = start; sipp < stop; sipp++) {
  216                 for (xipp = sipp + 1; xipp < stop; xipp++) {
  217                         if ((*sipp)->subsystem < (*xipp)->subsystem ||
  218                             ((*sipp)->subsystem == (*xipp)->subsystem &&
  219                             (*sipp)->order <= (*xipp)->order))
  220                                 continue;       /* skip */
  221                         save = *sipp;
  222                         *sipp = *xipp;
  223                         *xipp = save;
  224                 }
  225         }
  226 
  227         /*
  228          * Traverse the (now) ordered list of system initialization tasks.
  229          * Perform each task, and continue on to the next task.
  230          */
  231         mtx_lock(&Giant);
  232         for (sipp = start; sipp < stop; sipp++) {
  233                 if ((*sipp)->subsystem == SI_SUB_DUMMY)
  234                         continue;       /* skip dummy task(s) */
  235 
  236                 /* Call function */
  237                 (*((*sipp)->func)) ((*sipp)->udata);
  238         }
  239         mtx_unlock(&Giant);
  240 }
  241 
  242 static void
  243 linker_file_sysuninit(linker_file_t lf)
  244 {
  245         struct sysinit **start, **stop, **sipp, **xipp, *save;
  246 
  247         KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n",
  248             lf->filename));
  249 
  250         if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop,
  251             NULL) != 0)
  252                 return;
  253 
  254         /*
  255          * Perform a reverse bubble sort of the system initialization objects
  256          * by their subsystem (primary key) and order (secondary key).
  257          *
  258          * Since some things care about execution order, this is the operation
  259          * which ensures continued function.
  260          */
  261         for (sipp = start; sipp < stop; sipp++) {
  262                 for (xipp = sipp + 1; xipp < stop; xipp++) {
  263                         if ((*sipp)->subsystem > (*xipp)->subsystem ||
  264                             ((*sipp)->subsystem == (*xipp)->subsystem &&
  265                             (*sipp)->order >= (*xipp)->order))
  266                                 continue;       /* skip */
  267                         save = *sipp;
  268                         *sipp = *xipp;
  269                         *xipp = save;
  270                 }
  271         }
  272 
  273         /*
  274          * Traverse the (now) ordered list of system initialization tasks.
  275          * Perform each task, and continue on to the next task.
  276          */
  277         mtx_lock(&Giant);
  278         for (sipp = start; sipp < stop; sipp++) {
  279                 if ((*sipp)->subsystem == SI_SUB_DUMMY)
  280                         continue;       /* skip dummy task(s) */
  281 
  282                 /* Call function */
  283                 (*((*sipp)->func)) ((*sipp)->udata);
  284         }
  285         mtx_unlock(&Giant);
  286 }
  287 
  288 static void
  289 linker_file_register_sysctls(linker_file_t lf)
  290 {
  291         struct sysctl_oid **start, **stop, **oidp;
  292 
  293         KLD_DPF(FILE,
  294             ("linker_file_register_sysctls: registering SYSCTLs for %s\n",
  295             lf->filename));
  296 
  297         if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
  298                 return;
  299 
  300         sysctl_lock();
  301         for (oidp = start; oidp < stop; oidp++)
  302                 sysctl_register_oid(*oidp);
  303         sysctl_unlock();
  304 }
  305 
  306 static void
  307 linker_file_unregister_sysctls(linker_file_t lf)
  308 {
  309         struct sysctl_oid **start, **stop, **oidp;
  310 
  311         KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs"
  312             " for %s\n", lf->filename));
  313 
  314         if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
  315                 return;
  316 
  317         sysctl_lock();
  318         for (oidp = start; oidp < stop; oidp++)
  319                 sysctl_unregister_oid(*oidp);
  320         sysctl_unlock();
  321 }
  322 
  323 static int
  324 linker_file_register_modules(linker_file_t lf)
  325 {
  326         struct mod_metadata **start, **stop, **mdp;
  327         const moduledata_t *moddata;
  328         int first_error, error;
  329 
  330         KLD_DPF(FILE, ("linker_file_register_modules: registering modules"
  331             " in %s\n", lf->filename));
  332 
  333         if (linker_file_lookup_set(lf, "modmetadata_set", &start,
  334             &stop, NULL) != 0) {
  335                 /*
  336                  * This fallback should be unnecessary, but if we get booted
  337                  * from boot2 instead of loader and we are missing our
  338                  * metadata then we have to try the best we can.
  339                  */
  340                 if (lf == linker_kernel_file) {
  341                         start = SET_BEGIN(modmetadata_set);
  342                         stop = SET_LIMIT(modmetadata_set);
  343                 } else
  344                         return (0);
  345         }
  346         first_error = 0;
  347         for (mdp = start; mdp < stop; mdp++) {
  348                 if ((*mdp)->md_type != MDT_MODULE)
  349                         continue;
  350                 moddata = (*mdp)->md_data;
  351                 KLD_DPF(FILE, ("Registering module %s in %s\n",
  352                     moddata->name, lf->filename));
  353                 error = module_register(moddata, lf);
  354                 if (error) {
  355                         printf("Module %s failed to register: %d\n",
  356                             moddata->name, error);
  357                         if (first_error == 0)
  358                                 first_error = error;
  359                 }
  360         }
  361         return (first_error);
  362 }
  363 
  364 static void
  365 linker_init_kernel_modules(void)
  366 {
  367 
  368         linker_file_register_modules(linker_kernel_file);
  369 }
  370 
  371 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules,
  372     0);
  373 
  374 static int
  375 linker_load_file(const char *filename, linker_file_t *result)
  376 {
  377         linker_class_t lc;
  378         linker_file_t lf;
  379         int foundfile, error, modules;
  380 
  381         /* Refuse to load modules if securelevel raised */
  382         if (prison0.pr_securelevel > 0)
  383                 return (EPERM);
  384 
  385         KLD_LOCK_ASSERT();
  386         lf = linker_find_file_by_name(filename);
  387         if (lf) {
  388                 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded,"
  389                     " incrementing refs\n", filename));
  390                 *result = lf;
  391                 lf->refs++;
  392                 return (0);
  393         }
  394         foundfile = 0;
  395         error = 0;
  396 
  397         /*
  398          * We do not need to protect (lock) classes here because there is
  399          * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY)
  400          * and there is no class deregistration mechanism at this time.
  401          */
  402         TAILQ_FOREACH(lc, &classes, link) {
  403                 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n",
  404                     filename));
  405                 error = LINKER_LOAD_FILE(lc, filename, &lf);
  406                 /*
  407                  * If we got something other than ENOENT, then it exists but
  408                  * we cannot load it for some other reason.
  409                  */
  410                 if (error != ENOENT)
  411                         foundfile = 1;
  412                 if (lf) {
  413                         error = linker_file_register_modules(lf);
  414                         if (error == EEXIST) {
  415                                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
  416                                 return (error);
  417                         }
  418                         modules = !TAILQ_EMPTY(&lf->modules);
  419                         KLD_UNLOCK();
  420                         linker_file_register_sysctls(lf);
  421                         linker_file_sysinit(lf);
  422                         KLD_LOCK();
  423                         lf->flags |= LINKER_FILE_LINKED;
  424 
  425                         /*
  426                          * If all of the modules in this file failed
  427                          * to load, unload the file and return an
  428                          * error of ENOEXEC.
  429                          */
  430                         if (modules && TAILQ_EMPTY(&lf->modules)) {
  431                                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
  432                                 return (ENOEXEC);
  433                         }
  434                         *result = lf;
  435                         return (0);
  436                 }
  437         }
  438         /*
  439          * Less than ideal, but tells the user whether it failed to load or
  440          * the module was not found.
  441          */
  442         if (foundfile) {
  443 
  444                 /*
  445                  * If the file type has not been recognized by the last try
  446                  * printout a message before to fail.
  447                  */
  448                 if (error == ENOSYS)
  449                         printf("linker_load_file: Unsupported file type\n");
  450 
  451                 /*
  452                  * Format not recognized or otherwise unloadable.
  453                  * When loading a module that is statically built into
  454                  * the kernel EEXIST percolates back up as the return
  455                  * value.  Preserve this so that apps like sysinstall
  456                  * can recognize this special case and not post bogus
  457                  * dialog boxes.
  458                  */
  459                 if (error != EEXIST)
  460                         error = ENOEXEC;
  461         } else
  462                 error = ENOENT;         /* Nothing found */
  463         return (error);
  464 }
  465 
  466 int
  467 linker_reference_module(const char *modname, struct mod_depend *verinfo,
  468     linker_file_t *result)
  469 {
  470         modlist_t mod;
  471         int error;
  472 
  473         KLD_LOCK();
  474         if ((mod = modlist_lookup2(modname, verinfo)) != NULL) {
  475                 *result = mod->container;
  476                 (*result)->refs++;
  477                 KLD_UNLOCK();
  478                 return (0);
  479         }
  480 
  481         error = linker_load_module(NULL, modname, NULL, verinfo, result);
  482         KLD_UNLOCK();
  483         return (error);
  484 }
  485 
  486 int
  487 linker_release_module(const char *modname, struct mod_depend *verinfo,
  488     linker_file_t lf)
  489 {
  490         modlist_t mod;
  491         int error;
  492 
  493         KLD_LOCK();
  494         if (lf == NULL) {
  495                 KASSERT(modname != NULL,
  496                     ("linker_release_module: no file or name"));
  497                 mod = modlist_lookup2(modname, verinfo);
  498                 if (mod == NULL) {
  499                         KLD_UNLOCK();
  500                         return (ESRCH);
  501                 }
  502                 lf = mod->container;
  503         } else
  504                 KASSERT(modname == NULL && verinfo == NULL,
  505                     ("linker_release_module: both file and name"));
  506         error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL);
  507         KLD_UNLOCK();
  508         return (error);
  509 }
  510 
  511 static linker_file_t
  512 linker_find_file_by_name(const char *filename)
  513 {
  514         linker_file_t lf;
  515         char *koname;
  516 
  517         koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
  518         sprintf(koname, "%s.ko", filename);
  519 
  520         KLD_LOCK_ASSERT();
  521         TAILQ_FOREACH(lf, &linker_files, link) {
  522                 if (strcmp(lf->filename, koname) == 0)
  523                         break;
  524                 if (strcmp(lf->filename, filename) == 0)
  525                         break;
  526         }
  527         free(koname, M_LINKER);
  528         return (lf);
  529 }
  530 
  531 static linker_file_t
  532 linker_find_file_by_id(int fileid)
  533 {
  534         linker_file_t lf;
  535 
  536         KLD_LOCK_ASSERT();
  537         TAILQ_FOREACH(lf, &linker_files, link)
  538                 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED)
  539                         break;
  540         return (lf);
  541 }
  542 
  543 int
  544 linker_file_foreach(linker_predicate_t *predicate, void *context)
  545 {
  546         linker_file_t lf;
  547         int retval = 0;
  548 
  549         KLD_LOCK();
  550         TAILQ_FOREACH(lf, &linker_files, link) {
  551                 retval = predicate(lf, context);
  552                 if (retval != 0)
  553                         break;
  554         }
  555         KLD_UNLOCK();
  556         return (retval);
  557 }
  558 
  559 linker_file_t
  560 linker_make_file(const char *pathname, linker_class_t lc)
  561 {
  562         linker_file_t lf;
  563         const char *filename;
  564 
  565         KLD_LOCK_ASSERT();
  566         filename = linker_basename(pathname);
  567 
  568         KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname));
  569         lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK);
  570         if (lf == NULL)
  571                 return (NULL);
  572         lf->refs = 1;
  573         lf->userrefs = 0;
  574         lf->flags = 0;
  575         lf->filename = linker_strdup(filename);
  576         lf->pathname = linker_strdup(pathname);
  577         LINKER_GET_NEXT_FILE_ID(lf->id);
  578         lf->ndeps = 0;
  579         lf->deps = NULL;
  580         lf->loadcnt = ++loadcnt;
  581         lf->sdt_probes = NULL;
  582         lf->sdt_nprobes = 0;
  583         STAILQ_INIT(&lf->common);
  584         TAILQ_INIT(&lf->modules);
  585         TAILQ_INSERT_TAIL(&linker_files, lf, link);
  586         return (lf);
  587 }
  588 
  589 int
  590 linker_file_unload(linker_file_t file, int flags)
  591 {
  592         module_t mod, next;
  593         modlist_t ml, nextml;
  594         struct common_symbol *cp;
  595         int error, i;
  596 
  597         /* Refuse to unload modules if securelevel raised. */
  598         if (prison0.pr_securelevel > 0)
  599                 return (EPERM);
  600 
  601         KLD_LOCK_ASSERT();
  602         KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
  603 
  604         /* Easy case of just dropping a reference. */
  605         if (file->refs > 1) {
  606                 file->refs--;
  607                 return (0);
  608         }
  609 
  610         KLD_DPF(FILE, ("linker_file_unload: file is unloading,"
  611             " informing modules\n"));
  612 
  613         /*
  614          * Quiesce all the modules to give them a chance to veto the unload.
  615          */
  616         MOD_SLOCK;
  617         for (mod = TAILQ_FIRST(&file->modules); mod;
  618              mod = module_getfnext(mod)) {
  619 
  620                 error = module_quiesce(mod);
  621                 if (error != 0 && flags != LINKER_UNLOAD_FORCE) {
  622                         KLD_DPF(FILE, ("linker_file_unload: module %s"
  623                             " vetoed unload\n", module_getname(mod)));
  624                         /*
  625                          * XXX: Do we need to tell all the quiesced modules
  626                          * that they can resume work now via a new module
  627                          * event?
  628                          */
  629                         MOD_SUNLOCK;
  630                         return (error);
  631                 }
  632         }
  633         MOD_SUNLOCK;
  634 
  635         /*
  636          * Inform any modules associated with this file that they are
  637          * being unloaded.
  638          */
  639         MOD_XLOCK;
  640         for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
  641                 next = module_getfnext(mod);
  642                 MOD_XUNLOCK;
  643 
  644                 /*
  645                  * Give the module a chance to veto the unload.
  646                  */
  647                 if ((error = module_unload(mod)) != 0) {
  648 #ifdef KLD_DEBUG
  649                         MOD_SLOCK;
  650                         KLD_DPF(FILE, ("linker_file_unload: module %s"
  651                             " failed unload\n", module_getname(mod)));
  652                         MOD_SUNLOCK;
  653 #endif
  654                         return (error);
  655                 }
  656                 MOD_XLOCK;
  657                 module_release(mod);
  658         }
  659         MOD_XUNLOCK;
  660 
  661         TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) {
  662                 if (ml->container == file) {
  663                         TAILQ_REMOVE(&found_modules, ml, link);
  664                         free(ml, M_LINKER);
  665                 }
  666         }
  667 
  668         /*
  669          * Don't try to run SYSUNINITs if we are unloaded due to a
  670          * link error.
  671          */
  672         if (file->flags & LINKER_FILE_LINKED) {
  673                 file->flags &= ~LINKER_FILE_LINKED;
  674                 KLD_UNLOCK();
  675                 linker_file_sysuninit(file);
  676                 linker_file_unregister_sysctls(file);
  677                 KLD_LOCK();
  678         }
  679         TAILQ_REMOVE(&linker_files, file, link);
  680 
  681         if (file->deps) {
  682                 for (i = 0; i < file->ndeps; i++)
  683                         linker_file_unload(file->deps[i], flags);
  684                 free(file->deps, M_LINKER);
  685                 file->deps = NULL;
  686         }
  687         while ((cp = STAILQ_FIRST(&file->common)) != NULL) {
  688                 STAILQ_REMOVE_HEAD(&file->common, link);
  689                 free(cp, M_LINKER);
  690         }
  691 
  692         LINKER_UNLOAD(file);
  693         if (file->filename) {
  694                 free(file->filename, M_LINKER);
  695                 file->filename = NULL;
  696         }
  697         if (file->pathname) {
  698                 free(file->pathname, M_LINKER);
  699                 file->pathname = NULL;
  700         }
  701         kobj_delete((kobj_t) file, M_LINKER);
  702         return (0);
  703 }
  704 
  705 int
  706 linker_ctf_get(linker_file_t file, linker_ctf_t *lc)
  707 {
  708         return (LINKER_CTF_GET(file, lc));
  709 }
  710 
  711 static int
  712 linker_file_add_dependency(linker_file_t file, linker_file_t dep)
  713 {
  714         linker_file_t *newdeps;
  715 
  716         KLD_LOCK_ASSERT();
  717         newdeps = malloc((file->ndeps + 1) * sizeof(linker_file_t *),
  718             M_LINKER, M_WAITOK | M_ZERO);
  719         if (newdeps == NULL)
  720                 return (ENOMEM);
  721 
  722         if (file->deps) {
  723                 bcopy(file->deps, newdeps,
  724                     file->ndeps * sizeof(linker_file_t *));
  725                 free(file->deps, M_LINKER);
  726         }
  727         file->deps = newdeps;
  728         file->deps[file->ndeps] = dep;
  729         file->ndeps++;
  730         return (0);
  731 }
  732 
  733 /*
  734  * Locate a linker set and its contents.  This is a helper function to avoid
  735  * linker_if.h exposure elsewhere.  Note: firstp and lastp are really void **.
  736  * This function is used in this file so we can avoid having lots of (void **)
  737  * casts.
  738  */
  739 int
  740 linker_file_lookup_set(linker_file_t file, const char *name,
  741     void *firstp, void *lastp, int *countp)
  742 {
  743         int error, locked;
  744 
  745         locked = KLD_LOCKED();
  746         if (!locked)
  747                 KLD_LOCK();
  748         error = LINKER_LOOKUP_SET(file, name, firstp, lastp, countp);
  749         if (!locked)
  750                 KLD_UNLOCK();
  751         return (error);
  752 }
  753 
  754 /*
  755  * List all functions in a file.
  756  */
  757 int
  758 linker_file_function_listall(linker_file_t lf,
  759     linker_function_nameval_callback_t callback_func, void *arg)
  760 {
  761         return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg));
  762 }
  763 
  764 caddr_t
  765 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps)
  766 {
  767         caddr_t sym;
  768         int locked;
  769 
  770         locked = KLD_LOCKED();
  771         if (!locked)
  772                 KLD_LOCK();
  773         sym = linker_file_lookup_symbol_internal(file, name, deps);
  774         if (!locked)
  775                 KLD_UNLOCK();
  776         return (sym);
  777 }
  778 
  779 static caddr_t
  780 linker_file_lookup_symbol_internal(linker_file_t file, const char *name,
  781     int deps)
  782 {
  783         c_linker_sym_t sym;
  784         linker_symval_t symval;
  785         caddr_t address;
  786         size_t common_size = 0;
  787         int i;
  788 
  789         KLD_LOCK_ASSERT();
  790         KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n",
  791             file, name, deps));
  792 
  793         if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) {
  794                 LINKER_SYMBOL_VALUES(file, sym, &symval);
  795                 if (symval.value == 0)
  796                         /*
  797                          * For commons, first look them up in the
  798                          * dependencies and only allocate space if not found
  799                          * there.
  800                          */
  801                         common_size = symval.size;
  802                 else {
  803                         KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol"
  804                             ".value=%p\n", symval.value));
  805                         return (symval.value);
  806                 }
  807         }
  808         if (deps) {
  809                 for (i = 0; i < file->ndeps; i++) {
  810                         address = linker_file_lookup_symbol_internal(
  811                             file->deps[i], name, 0);
  812                         if (address) {
  813                                 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
  814                                     " deps value=%p\n", address));
  815                                 return (address);
  816                         }
  817                 }
  818         }
  819         if (common_size > 0) {
  820                 /*
  821                  * This is a common symbol which was not found in the
  822                  * dependencies.  We maintain a simple common symbol table in
  823                  * the file object.
  824                  */
  825                 struct common_symbol *cp;
  826 
  827                 STAILQ_FOREACH(cp, &file->common, link) {
  828                         if (strcmp(cp->name, name) == 0) {
  829                                 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
  830                                     " old common value=%p\n", cp->address));
  831                                 return (cp->address);
  832                         }
  833                 }
  834                 /*
  835                  * Round the symbol size up to align.
  836                  */
  837                 common_size = (common_size + sizeof(int) - 1) & -sizeof(int);
  838                 cp = malloc(sizeof(struct common_symbol)
  839                     + common_size + strlen(name) + 1, M_LINKER,
  840                     M_WAITOK | M_ZERO);
  841                 cp->address = (caddr_t)(cp + 1);
  842                 cp->name = cp->address + common_size;
  843                 strcpy(cp->name, name);
  844                 bzero(cp->address, common_size);
  845                 STAILQ_INSERT_TAIL(&file->common, cp, link);
  846 
  847                 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common"
  848                     " value=%p\n", cp->address));
  849                 return (cp->address);
  850         }
  851         KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
  852         return (0);
  853 }
  854 
  855 /*
  856  * Both DDB and stack(9) rely on the kernel linker to provide forward and
  857  * backward lookup of symbols.  However, DDB and sometimes stack(9) need to
  858  * do this in a lockfree manner.  We provide a set of internal helper
  859  * routines to perform these operations without locks, and then wrappers that
  860  * optionally lock.
  861  *
  862  * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB.
  863  */
  864 #ifdef DDB
  865 static int
  866 linker_debug_lookup(const char *symstr, c_linker_sym_t *sym)
  867 {
  868         linker_file_t lf;
  869 
  870         TAILQ_FOREACH(lf, &linker_files, link) {
  871                 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0)
  872                         return (0);
  873         }
  874         return (ENOENT);
  875 }
  876 #endif
  877 
  878 static int
  879 linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
  880 {
  881         linker_file_t lf;
  882         c_linker_sym_t best, es;
  883         u_long diff, bestdiff, off;
  884 
  885         best = 0;
  886         off = (uintptr_t)value;
  887         bestdiff = off;
  888         TAILQ_FOREACH(lf, &linker_files, link) {
  889                 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0)
  890                         continue;
  891                 if (es != 0 && diff < bestdiff) {
  892                         best = es;
  893                         bestdiff = diff;
  894                 }
  895                 if (bestdiff == 0)
  896                         break;
  897         }
  898         if (best) {
  899                 *sym = best;
  900                 *diffp = bestdiff;
  901                 return (0);
  902         } else {
  903                 *sym = 0;
  904                 *diffp = off;
  905                 return (ENOENT);
  906         }
  907 }
  908 
  909 static int
  910 linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
  911 {
  912         linker_file_t lf;
  913 
  914         TAILQ_FOREACH(lf, &linker_files, link) {
  915                 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0)
  916                         return (0);
  917         }
  918         return (ENOENT);
  919 }
  920 
  921 static int
  922 linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen,
  923     long *offset)
  924 {
  925         linker_symval_t symval;
  926         c_linker_sym_t sym;
  927         int error;
  928 
  929         *offset = 0;
  930         error = linker_debug_search_symbol(value, &sym, offset);
  931         if (error)
  932                 return (error);
  933         error = linker_debug_symbol_values(sym, &symval);
  934         if (error)
  935                 return (error);
  936         strlcpy(buf, symval.name, buflen);
  937         return (0);
  938 }
  939 
  940 /*
  941  * DDB Helpers.  DDB has to look across multiple files with their own symbol
  942  * tables and string tables.
  943  *
  944  * Note that we do not obey list locking protocols here.  We really don't need
  945  * DDB to hang because somebody's got the lock held.  We'll take the chance
  946  * that the files list is inconsistant instead.
  947  */
  948 #ifdef DDB
  949 int
  950 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
  951 {
  952 
  953         return (linker_debug_lookup(symstr, sym));
  954 }
  955 #endif
  956 
  957 int
  958 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
  959 {
  960 
  961         return (linker_debug_search_symbol(value, sym, diffp));
  962 }
  963 
  964 int
  965 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
  966 {
  967 
  968         return (linker_debug_symbol_values(sym, symval));
  969 }
  970 
  971 int
  972 linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen,
  973     long *offset)
  974 {
  975 
  976         return (linker_debug_search_symbol_name(value, buf, buflen, offset));
  977 }
  978 
  979 /*
  980  * stack(9) helper for non-debugging environemnts.  Unlike DDB helpers, we do
  981  * obey locking protocols, and offer a significantly less complex interface.
  982  */
  983 int
  984 linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
  985     long *offset)
  986 {
  987         int error;
  988 
  989         KLD_LOCK();
  990         error = linker_debug_search_symbol_name(value, buf, buflen, offset);
  991         KLD_UNLOCK();
  992         return (error);
  993 }
  994 
  995 /*
  996  * Syscalls.
  997  */
  998 int
  999 kern_kldload(struct thread *td, const char *file, int *fileid)
 1000 {
 1001 #ifdef HWPMC_HOOKS
 1002         struct pmckern_map_in pkm;
 1003 #endif
 1004         const char *kldname, *modname;
 1005         linker_file_t lf;
 1006         int error;
 1007 
 1008         if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
 1009                 return (error);
 1010 
 1011         if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0)
 1012                 return (error);
 1013 
 1014         /*
 1015          * It is possible that kldloaded module will attach a new ifnet,
 1016          * so vnet context must be set when this ocurs.
 1017          */
 1018         CURVNET_SET(TD_TO_VNET(td));
 1019 
 1020         /*
 1021          * If file does not contain a qualified name or any dot in it
 1022          * (kldname.ko, or kldname.ver.ko) treat it as an interface
 1023          * name.
 1024          */
 1025         if (index(file, '/') || index(file, '.')) {
 1026                 kldname = file;
 1027                 modname = NULL;
 1028         } else {
 1029                 kldname = NULL;
 1030                 modname = file;
 1031         }
 1032 
 1033         KLD_LOCK();
 1034         error = linker_load_module(kldname, modname, NULL, NULL, &lf);
 1035         if (error) {
 1036                 KLD_UNLOCK();
 1037                 goto done;
 1038         }
 1039         lf->userrefs++;
 1040         if (fileid != NULL)
 1041                 *fileid = lf->id;
 1042 #ifdef HWPMC_HOOKS
 1043         KLD_DOWNGRADE();
 1044         pkm.pm_file = lf->filename;
 1045         pkm.pm_address = (uintptr_t) lf->address;
 1046         PMC_CALL_HOOK(td, PMC_FN_KLD_LOAD, (void *) &pkm);
 1047         KLD_UNLOCK_READ();
 1048 #else
 1049         KLD_UNLOCK();
 1050 #endif
 1051 
 1052 done:
 1053         CURVNET_RESTORE();
 1054         return (error);
 1055 }
 1056 
 1057 int
 1058 kldload(struct thread *td, struct kldload_args *uap)
 1059 {
 1060         char *pathname = NULL;
 1061         int error, fileid;
 1062 
 1063         td->td_retval[0] = -1;
 1064 
 1065         pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
 1066         error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL);
 1067         if (error == 0) {
 1068                 error = kern_kldload(td, pathname, &fileid);
 1069                 if (error == 0)
 1070                         td->td_retval[0] = fileid;
 1071         }
 1072         free(pathname, M_TEMP);
 1073         return (error);
 1074 }
 1075 
 1076 int
 1077 kern_kldunload(struct thread *td, int fileid, int flags)
 1078 {
 1079 #ifdef HWPMC_HOOKS
 1080         struct pmckern_map_out pkm;
 1081 #endif
 1082         linker_file_t lf;
 1083         int error = 0;
 1084 
 1085         if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
 1086                 return (error);
 1087 
 1088         if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0)
 1089                 return (error);
 1090 
 1091         CURVNET_SET(TD_TO_VNET(td));
 1092         KLD_LOCK();
 1093         lf = linker_find_file_by_id(fileid);
 1094         if (lf) {
 1095                 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
 1096 
 1097                 /* Check if there are DTrace probes enabled on this file. */
 1098                 if (lf->nenabled > 0) {
 1099                         printf("kldunload: attempt to unload file that has"
 1100                             " DTrace probes enabled\n");
 1101                         error = EBUSY;
 1102                 } else if (lf->userrefs == 0) {
 1103                         /*
 1104                          * XXX: maybe LINKER_UNLOAD_FORCE should override ?
 1105                          */
 1106                         printf("kldunload: attempt to unload file that was"
 1107                             " loaded by the kernel\n");
 1108                         error = EBUSY;
 1109                 } else {
 1110 #ifdef HWPMC_HOOKS
 1111                         /* Save data needed by hwpmc(4) before unloading. */
 1112                         pkm.pm_address = (uintptr_t) lf->address;
 1113                         pkm.pm_size = lf->size;
 1114 #endif
 1115                         lf->userrefs--;
 1116                         error = linker_file_unload(lf, flags);
 1117                         if (error)
 1118                                 lf->userrefs++;
 1119                 }
 1120         } else
 1121                 error = ENOENT;
 1122 
 1123 #ifdef HWPMC_HOOKS
 1124         if (error == 0) {
 1125                 KLD_DOWNGRADE();
 1126                 PMC_CALL_HOOK(td, PMC_FN_KLD_UNLOAD, (void *) &pkm);
 1127                 KLD_UNLOCK_READ();
 1128         } else
 1129                 KLD_UNLOCK();
 1130 #else
 1131         KLD_UNLOCK();
 1132 #endif
 1133         CURVNET_RESTORE();
 1134         return (error);
 1135 }
 1136 
 1137 int
 1138 kldunload(struct thread *td, struct kldunload_args *uap)
 1139 {
 1140 
 1141         return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL));
 1142 }
 1143 
 1144 int
 1145 kldunloadf(struct thread *td, struct kldunloadf_args *uap)
 1146 {
 1147 
 1148         if (uap->flags != LINKER_UNLOAD_NORMAL &&
 1149             uap->flags != LINKER_UNLOAD_FORCE)
 1150                 return (EINVAL);
 1151         return (kern_kldunload(td, uap->fileid, uap->flags));
 1152 }
 1153 
 1154 int
 1155 kldfind(struct thread *td, struct kldfind_args *uap)
 1156 {
 1157         char *pathname;
 1158         const char *filename;
 1159         linker_file_t lf;
 1160         int error;
 1161 
 1162 #ifdef MAC
 1163         error = mac_kld_check_stat(td->td_ucred);
 1164         if (error)
 1165                 return (error);
 1166 #endif
 1167 
 1168         td->td_retval[0] = -1;
 1169 
 1170         pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
 1171         if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0)
 1172                 goto out;
 1173 
 1174         filename = linker_basename(pathname);
 1175         KLD_LOCK();
 1176         lf = linker_find_file_by_name(filename);
 1177         if (lf)
 1178                 td->td_retval[0] = lf->id;
 1179         else
 1180                 error = ENOENT;
 1181         KLD_UNLOCK();
 1182 out:
 1183         free(pathname, M_TEMP);
 1184         return (error);
 1185 }
 1186 
 1187 int
 1188 kldnext(struct thread *td, struct kldnext_args *uap)
 1189 {
 1190         linker_file_t lf;
 1191         int error = 0;
 1192 
 1193 #ifdef MAC
 1194         error = mac_kld_check_stat(td->td_ucred);
 1195         if (error)
 1196                 return (error);
 1197 #endif
 1198 
 1199         KLD_LOCK();
 1200         if (uap->fileid == 0)
 1201                 lf = TAILQ_FIRST(&linker_files);
 1202         else {
 1203                 lf = linker_find_file_by_id(uap->fileid);
 1204                 if (lf == NULL) {
 1205                         error = ENOENT;
 1206                         goto out;
 1207                 }
 1208                 lf = TAILQ_NEXT(lf, link);
 1209         }
 1210 
 1211         /* Skip partially loaded files. */
 1212         while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED))
 1213                 lf = TAILQ_NEXT(lf, link);
 1214 
 1215         if (lf)
 1216                 td->td_retval[0] = lf->id;
 1217         else
 1218                 td->td_retval[0] = 0;
 1219 out:
 1220         KLD_UNLOCK();
 1221         return (error);
 1222 }
 1223 
 1224 int
 1225 kldstat(struct thread *td, struct kldstat_args *uap)
 1226 {
 1227         struct kld_file_stat stat;
 1228         int error, version;
 1229 
 1230         /*
 1231          * Check the version of the user's structure.
 1232          */
 1233         if ((error = copyin(&uap->stat->version, &version, sizeof(version)))
 1234             != 0)
 1235                 return (error);
 1236         if (version != sizeof(struct kld_file_stat_1) &&
 1237             version != sizeof(struct kld_file_stat))
 1238                 return (EINVAL);
 1239 
 1240         error = kern_kldstat(td, uap->fileid, &stat);
 1241         if (error != 0)
 1242                 return (error);
 1243         return (copyout(&stat, uap->stat, version));
 1244 }
 1245 
 1246 int
 1247 kern_kldstat(struct thread *td, int fileid, struct kld_file_stat *stat)
 1248 {
 1249         linker_file_t lf;
 1250         int namelen;
 1251 #ifdef MAC
 1252         int error;
 1253 
 1254         error = mac_kld_check_stat(td->td_ucred);
 1255         if (error)
 1256                 return (error);
 1257 #endif
 1258 
 1259         KLD_LOCK();
 1260         lf = linker_find_file_by_id(fileid);
 1261         if (lf == NULL) {
 1262                 KLD_UNLOCK();
 1263                 return (ENOENT);
 1264         }
 1265 
 1266         /* Version 1 fields: */
 1267         namelen = strlen(lf->filename) + 1;
 1268         if (namelen > MAXPATHLEN)
 1269                 namelen = MAXPATHLEN;
 1270         bcopy(lf->filename, &stat->name[0], namelen);
 1271         stat->refs = lf->refs;
 1272         stat->id = lf->id;
 1273         stat->address = lf->address;
 1274         stat->size = lf->size;
 1275         /* Version 2 fields: */
 1276         namelen = strlen(lf->pathname) + 1;
 1277         if (namelen > MAXPATHLEN)
 1278                 namelen = MAXPATHLEN;
 1279         bcopy(lf->pathname, &stat->pathname[0], namelen);
 1280         KLD_UNLOCK();
 1281 
 1282         td->td_retval[0] = 0;
 1283         return (0);
 1284 }
 1285 
 1286 int
 1287 kldfirstmod(struct thread *td, struct kldfirstmod_args *uap)
 1288 {
 1289         linker_file_t lf;
 1290         module_t mp;
 1291         int error = 0;
 1292 
 1293 #ifdef MAC
 1294         error = mac_kld_check_stat(td->td_ucred);
 1295         if (error)
 1296                 return (error);
 1297 #endif
 1298 
 1299         KLD_LOCK();
 1300         lf = linker_find_file_by_id(uap->fileid);
 1301         if (lf) {
 1302                 MOD_SLOCK;
 1303                 mp = TAILQ_FIRST(&lf->modules);
 1304                 if (mp != NULL)
 1305                         td->td_retval[0] = module_getid(mp);
 1306                 else
 1307                         td->td_retval[0] = 0;
 1308                 MOD_SUNLOCK;
 1309         } else
 1310                 error = ENOENT;
 1311         KLD_UNLOCK();
 1312         return (error);
 1313 }
 1314 
 1315 int
 1316 kldsym(struct thread *td, struct kldsym_args *uap)
 1317 {
 1318         char *symstr = NULL;
 1319         c_linker_sym_t sym;
 1320         linker_symval_t symval;
 1321         linker_file_t lf;
 1322         struct kld_sym_lookup lookup;
 1323         int error = 0;
 1324 
 1325 #ifdef MAC
 1326         error = mac_kld_check_stat(td->td_ucred);
 1327         if (error)
 1328                 return (error);
 1329 #endif
 1330 
 1331         if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0)
 1332                 return (error);
 1333         if (lookup.version != sizeof(lookup) ||
 1334             uap->cmd != KLDSYM_LOOKUP)
 1335                 return (EINVAL);
 1336         symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
 1337         if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
 1338                 goto out;
 1339         KLD_LOCK();
 1340         if (uap->fileid != 0) {
 1341                 lf = linker_find_file_by_id(uap->fileid);
 1342                 if (lf == NULL)
 1343                         error = ENOENT;
 1344                 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
 1345                     LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
 1346                         lookup.symvalue = (uintptr_t) symval.value;
 1347                         lookup.symsize = symval.size;
 1348                         error = copyout(&lookup, uap->data, sizeof(lookup));
 1349                 } else
 1350                         error = ENOENT;
 1351         } else {
 1352                 TAILQ_FOREACH(lf, &linker_files, link) {
 1353                         if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
 1354                             LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
 1355                                 lookup.symvalue = (uintptr_t)symval.value;
 1356                                 lookup.symsize = symval.size;
 1357                                 error = copyout(&lookup, uap->data,
 1358                                     sizeof(lookup));
 1359                                 break;
 1360                         }
 1361                 }
 1362                 if (lf == NULL)
 1363                         error = ENOENT;
 1364         }
 1365         KLD_UNLOCK();
 1366 out:
 1367         free(symstr, M_TEMP);
 1368         return (error);
 1369 }
 1370 
 1371 /*
 1372  * Preloaded module support
 1373  */
 1374 
 1375 static modlist_t
 1376 modlist_lookup(const char *name, int ver)
 1377 {
 1378         modlist_t mod;
 1379 
 1380         TAILQ_FOREACH(mod, &found_modules, link) {
 1381                 if (strcmp(mod->name, name) == 0 &&
 1382                     (ver == 0 || mod->version == ver))
 1383                         return (mod);
 1384         }
 1385         return (NULL);
 1386 }
 1387 
 1388 static modlist_t
 1389 modlist_lookup2(const char *name, struct mod_depend *verinfo)
 1390 {
 1391         modlist_t mod, bestmod;
 1392         int ver;
 1393 
 1394         if (verinfo == NULL)
 1395                 return (modlist_lookup(name, 0));
 1396         bestmod = NULL;
 1397         TAILQ_FOREACH(mod, &found_modules, link) {
 1398                 if (strcmp(mod->name, name) != 0)
 1399                         continue;
 1400                 ver = mod->version;
 1401                 if (ver == verinfo->md_ver_preferred)
 1402                         return (mod);
 1403                 if (ver >= verinfo->md_ver_minimum &&
 1404                     ver <= verinfo->md_ver_maximum &&
 1405                     (bestmod == NULL || ver > bestmod->version))
 1406                         bestmod = mod;
 1407         }
 1408         return (bestmod);
 1409 }
 1410 
 1411 static modlist_t
 1412 modlist_newmodule(const char *modname, int version, linker_file_t container)
 1413 {
 1414         modlist_t mod;
 1415 
 1416         mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO);
 1417         if (mod == NULL)
 1418                 panic("no memory for module list");
 1419         mod->container = container;
 1420         mod->name = modname;
 1421         mod->version = version;
 1422         TAILQ_INSERT_TAIL(&found_modules, mod, link);
 1423         return (mod);
 1424 }
 1425 
 1426 static void
 1427 linker_addmodules(linker_file_t lf, struct mod_metadata **start,
 1428     struct mod_metadata **stop, int preload)
 1429 {
 1430         struct mod_metadata *mp, **mdp;
 1431         const char *modname;
 1432         int ver;
 1433 
 1434         for (mdp = start; mdp < stop; mdp++) {
 1435                 mp = *mdp;
 1436                 if (mp->md_type != MDT_VERSION)
 1437                         continue;
 1438                 modname = mp->md_cval;
 1439                 ver = ((struct mod_version *)mp->md_data)->mv_version;
 1440                 if (modlist_lookup(modname, ver) != NULL) {
 1441                         printf("module %s already present!\n", modname);
 1442                         /* XXX what can we do? this is a build error. :-( */
 1443                         continue;
 1444                 }
 1445                 modlist_newmodule(modname, ver, lf);
 1446         }
 1447 }
 1448 
 1449 static void
 1450 linker_preload(void *arg)
 1451 {
 1452         caddr_t modptr;
 1453         const char *modname, *nmodname;
 1454         char *modtype;
 1455         linker_file_t lf, nlf;
 1456         linker_class_t lc;
 1457         int error;
 1458         linker_file_list_t loaded_files;
 1459         linker_file_list_t depended_files;
 1460         struct mod_metadata *mp, *nmp;
 1461         struct mod_metadata **start, **stop, **mdp, **nmdp;
 1462         struct mod_depend *verinfo;
 1463         int nver;
 1464         int resolves;
 1465         modlist_t mod;
 1466         struct sysinit **si_start, **si_stop;
 1467 
 1468         TAILQ_INIT(&loaded_files);
 1469         TAILQ_INIT(&depended_files);
 1470         TAILQ_INIT(&found_modules);
 1471         error = 0;
 1472 
 1473         modptr = NULL;
 1474         while ((modptr = preload_search_next_name(modptr)) != NULL) {
 1475                 modname = (char *)preload_search_info(modptr, MODINFO_NAME);
 1476                 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
 1477                 if (modname == NULL) {
 1478                         printf("Preloaded module at %p does not have a"
 1479                             " name!\n", modptr);
 1480                         continue;
 1481                 }
 1482                 if (modtype == NULL) {
 1483                         printf("Preloaded module at %p does not have a type!\n",
 1484                             modptr);
 1485                         continue;
 1486                 }
 1487                 if (bootverbose)
 1488                         printf("Preloaded %s \"%s\" at %p.\n", modtype, modname,
 1489                             modptr);
 1490                 lf = NULL;
 1491                 TAILQ_FOREACH(lc, &classes, link) {
 1492                         error = LINKER_LINK_PRELOAD(lc, modname, &lf);
 1493                         if (!error)
 1494                                 break;
 1495                         lf = NULL;
 1496                 }
 1497                 if (lf)
 1498                         TAILQ_INSERT_TAIL(&loaded_files, lf, loaded);
 1499         }
 1500 
 1501         /*
 1502          * First get a list of stuff in the kernel.
 1503          */
 1504         if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start,
 1505             &stop, NULL) == 0)
 1506                 linker_addmodules(linker_kernel_file, start, stop, 1);
 1507 
 1508         /*
 1509          * This is a once-off kinky bubble sort to resolve relocation
 1510          * dependency requirements.
 1511          */
 1512 restart:
 1513         TAILQ_FOREACH(lf, &loaded_files, loaded) {
 1514                 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
 1515                     &stop, NULL);
 1516                 /*
 1517                  * First, look to see if we would successfully link with this
 1518                  * stuff.
 1519                  */
 1520                 resolves = 1;   /* unless we know otherwise */
 1521                 if (!error) {
 1522                         for (mdp = start; mdp < stop; mdp++) {
 1523                                 mp = *mdp;
 1524                                 if (mp->md_type != MDT_DEPEND)
 1525                                         continue;
 1526                                 modname = mp->md_cval;
 1527                                 verinfo = mp->md_data;
 1528                                 for (nmdp = start; nmdp < stop; nmdp++) {
 1529                                         nmp = *nmdp;
 1530                                         if (nmp->md_type != MDT_VERSION)
 1531                                                 continue;
 1532                                         nmodname = nmp->md_cval;
 1533                                         if (strcmp(modname, nmodname) == 0)
 1534                                                 break;
 1535                                 }
 1536                                 if (nmdp < stop)   /* it's a self reference */
 1537                                         continue;
 1538 
 1539                                 /*
 1540                                  * ok, the module isn't here yet, we
 1541                                  * are not finished
 1542                                  */
 1543                                 if (modlist_lookup2(modname, verinfo) == NULL)
 1544                                         resolves = 0;
 1545                         }
 1546                 }
 1547                 /*
 1548                  * OK, if we found our modules, we can link.  So, "provide"
 1549                  * the modules inside and add it to the end of the link order
 1550                  * list.
 1551                  */
 1552                 if (resolves) {
 1553                         if (!error) {
 1554                                 for (mdp = start; mdp < stop; mdp++) {
 1555                                         mp = *mdp;
 1556                                         if (mp->md_type != MDT_VERSION)
 1557                                                 continue;
 1558                                         modname = mp->md_cval;
 1559                                         nver = ((struct mod_version *)
 1560                                             mp->md_data)->mv_version;
 1561                                         if (modlist_lookup(modname,
 1562                                             nver) != NULL) {
 1563                                                 printf("module %s already"
 1564                                                     " present!\n", modname);
 1565                                                 TAILQ_REMOVE(&loaded_files,
 1566                                                     lf, loaded);
 1567                                                 linker_file_unload(lf,
 1568                                                     LINKER_UNLOAD_FORCE);
 1569                                                 /* we changed tailq next ptr */
 1570                                                 goto restart;
 1571                                         }
 1572                                         modlist_newmodule(modname, nver, lf);
 1573                                 }
 1574                         }
 1575                         TAILQ_REMOVE(&loaded_files, lf, loaded);
 1576                         TAILQ_INSERT_TAIL(&depended_files, lf, loaded);
 1577                         /*
 1578                          * Since we provided modules, we need to restart the
 1579                          * sort so that the previous files that depend on us
 1580                          * have a chance. Also, we've busted the tailq next
 1581                          * pointer with the REMOVE.
 1582                          */
 1583                         goto restart;
 1584                 }
 1585         }
 1586 
 1587         /*
 1588          * At this point, we check to see what could not be resolved..
 1589          */
 1590         while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) {
 1591                 TAILQ_REMOVE(&loaded_files, lf, loaded);
 1592                 printf("KLD file %s is missing dependencies\n", lf->filename);
 1593                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 1594         }
 1595 
 1596         /*
 1597          * We made it. Finish off the linking in the order we determined.
 1598          */
 1599         TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) {
 1600                 if (linker_kernel_file) {
 1601                         linker_kernel_file->refs++;
 1602                         error = linker_file_add_dependency(lf,
 1603                             linker_kernel_file);
 1604                         if (error)
 1605                                 panic("cannot add dependency");
 1606                 }
 1607                 lf->userrefs++; /* so we can (try to) kldunload it */
 1608                 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
 1609                     &stop, NULL);
 1610                 if (!error) {
 1611                         for (mdp = start; mdp < stop; mdp++) {
 1612                                 mp = *mdp;
 1613                                 if (mp->md_type != MDT_DEPEND)
 1614                                         continue;
 1615                                 modname = mp->md_cval;
 1616                                 verinfo = mp->md_data;
 1617                                 mod = modlist_lookup2(modname, verinfo);
 1618                                 /* Don't count self-dependencies */
 1619                                 if (lf == mod->container)
 1620                                         continue;
 1621                                 mod->container->refs++;
 1622                                 error = linker_file_add_dependency(lf,
 1623                                     mod->container);
 1624                                 if (error)
 1625                                         panic("cannot add dependency");
 1626                         }
 1627                 }
 1628                 /*
 1629                  * Now do relocation etc using the symbol search paths
 1630                  * established by the dependencies
 1631                  */
 1632                 error = LINKER_LINK_PRELOAD_FINISH(lf);
 1633                 if (error) {
 1634                         TAILQ_REMOVE(&depended_files, lf, loaded);
 1635                         printf("KLD file %s - could not finalize loading\n",
 1636                             lf->filename);
 1637                         linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 1638                         continue;
 1639                 }
 1640                 linker_file_register_modules(lf);
 1641                 if (linker_file_lookup_set(lf, "sysinit_set", &si_start,
 1642                     &si_stop, NULL) == 0)
 1643                         sysinit_add(si_start, si_stop);
 1644                 linker_file_register_sysctls(lf);
 1645                 lf->flags |= LINKER_FILE_LINKED;
 1646         }
 1647         /* woohoo! we made it! */
 1648 }
 1649 
 1650 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0);
 1651 
 1652 /*
 1653  * Search for a not-loaded module by name.
 1654  *
 1655  * Modules may be found in the following locations:
 1656  *
 1657  * - preloaded (result is just the module name) - on disk (result is full path
 1658  * to module)
 1659  *
 1660  * If the module name is qualified in any way (contains path, etc.) the we
 1661  * simply return a copy of it.
 1662  *
 1663  * The search path can be manipulated via sysctl.  Note that we use the ';'
 1664  * character as a separator to be consistent with the bootloader.
 1665  */
 1666 
 1667 static char linker_hintfile[] = "linker.hints";
 1668 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules";
 1669 
 1670 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path,
 1671     sizeof(linker_path), "module load search path");
 1672 
 1673 TUNABLE_STR("module_path", linker_path, sizeof(linker_path));
 1674 
 1675 static char *linker_ext_list[] = {
 1676         "",
 1677         ".ko",
 1678         NULL
 1679 };
 1680 
 1681 /*
 1682  * Check if file actually exists either with or without extension listed in
 1683  * the linker_ext_list. (probably should be generic for the rest of the
 1684  * kernel)
 1685  */
 1686 static char *
 1687 linker_lookup_file(const char *path, int pathlen, const char *name,
 1688     int namelen, struct vattr *vap)
 1689 {
 1690         struct nameidata nd;
 1691         struct thread *td = curthread;  /* XXX */
 1692         char *result, **cpp, *sep;
 1693         int error, len, extlen, reclen, flags, vfslocked;
 1694         enum vtype type;
 1695 
 1696         extlen = 0;
 1697         for (cpp = linker_ext_list; *cpp; cpp++) {
 1698                 len = strlen(*cpp);
 1699                 if (len > extlen)
 1700                         extlen = len;
 1701         }
 1702         extlen++;               /* trailing '\0' */
 1703         sep = (path[pathlen - 1] != '/') ? "/" : "";
 1704 
 1705         reclen = pathlen + strlen(sep) + namelen + extlen + 1;
 1706         result = malloc(reclen, M_LINKER, M_WAITOK);
 1707         for (cpp = linker_ext_list; *cpp; cpp++) {
 1708                 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep,
 1709                     namelen, name, *cpp);
 1710                 /*
 1711                  * Attempt to open the file, and return the path if
 1712                  * we succeed and it's a regular file.
 1713                  */
 1714                 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, result, td);
 1715                 flags = FREAD;
 1716                 error = vn_open(&nd, &flags, 0, NULL);
 1717                 if (error == 0) {
 1718                         vfslocked = NDHASGIANT(&nd);
 1719                         NDFREE(&nd, NDF_ONLY_PNBUF);
 1720                         type = nd.ni_vp->v_type;
 1721                         if (vap)
 1722                                 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred);
 1723                         VOP_UNLOCK(nd.ni_vp, 0);
 1724                         vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
 1725                         VFS_UNLOCK_GIANT(vfslocked);
 1726                         if (type == VREG)
 1727                                 return (result);
 1728                 }
 1729         }
 1730         free(result, M_LINKER);
 1731         return (NULL);
 1732 }
 1733 
 1734 #define INT_ALIGN(base, ptr)    ptr =                                   \
 1735         (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1))
 1736 
 1737 /*
 1738  * Lookup KLD which contains requested module in the "linker.hints" file. If
 1739  * version specification is available, then try to find the best KLD.
 1740  * Otherwise just find the latest one.
 1741  */
 1742 static char *
 1743 linker_hints_lookup(const char *path, int pathlen, const char *modname,
 1744     int modnamelen, struct mod_depend *verinfo)
 1745 {
 1746         struct thread *td = curthread;  /* XXX */
 1747         struct ucred *cred = td ? td->td_ucred : NULL;
 1748         struct nameidata nd;
 1749         struct vattr vattr, mattr;
 1750         u_char *hints = NULL;
 1751         u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep;
 1752         int error, ival, bestver, *intp, reclen, found, flags, clen, blen;
 1753         int vfslocked = 0;
 1754 
 1755         result = NULL;
 1756         bestver = found = 0;
 1757 
 1758         sep = (path[pathlen - 1] != '/') ? "/" : "";
 1759         reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen +
 1760             strlen(sep) + 1;
 1761         pathbuf = malloc(reclen, M_LINKER, M_WAITOK);
 1762         snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep,
 1763             linker_hintfile);
 1764 
 1765         NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, pathbuf, td);
 1766         flags = FREAD;
 1767         error = vn_open(&nd, &flags, 0, NULL);
 1768         if (error)
 1769                 goto bad;
 1770         vfslocked = NDHASGIANT(&nd);
 1771         NDFREE(&nd, NDF_ONLY_PNBUF);
 1772         if (nd.ni_vp->v_type != VREG)
 1773                 goto bad;
 1774         best = cp = NULL;
 1775         error = VOP_GETATTR(nd.ni_vp, &vattr, cred);
 1776         if (error)
 1777                 goto bad;
 1778         /*
 1779          * XXX: we need to limit this number to some reasonable value
 1780          */
 1781         if (vattr.va_size > 100 * 1024) {
 1782                 printf("hints file too large %ld\n", (long)vattr.va_size);
 1783                 goto bad;
 1784         }
 1785         hints = malloc(vattr.va_size, M_TEMP, M_WAITOK);
 1786         if (hints == NULL)
 1787                 goto bad;
 1788         error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0,
 1789             UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td);
 1790         if (error)
 1791                 goto bad;
 1792         VOP_UNLOCK(nd.ni_vp, 0);
 1793         vn_close(nd.ni_vp, FREAD, cred, td);
 1794         VFS_UNLOCK_GIANT(vfslocked);
 1795         nd.ni_vp = NULL;
 1796         if (reclen != 0) {
 1797                 printf("can't read %d\n", reclen);
 1798                 goto bad;
 1799         }
 1800         intp = (int *)hints;
 1801         ival = *intp++;
 1802         if (ival != LINKER_HINTS_VERSION) {
 1803                 printf("hints file version mismatch %d\n", ival);
 1804                 goto bad;
 1805         }
 1806         bufend = hints + vattr.va_size;
 1807         recptr = (u_char *)intp;
 1808         clen = blen = 0;
 1809         while (recptr < bufend && !found) {
 1810                 intp = (int *)recptr;
 1811                 reclen = *intp++;
 1812                 ival = *intp++;
 1813                 cp = (char *)intp;
 1814                 switch (ival) {
 1815                 case MDT_VERSION:
 1816                         clen = *cp++;
 1817                         if (clen != modnamelen || bcmp(cp, modname, clen) != 0)
 1818                                 break;
 1819                         cp += clen;
 1820                         INT_ALIGN(hints, cp);
 1821                         ival = *(int *)cp;
 1822                         cp += sizeof(int);
 1823                         clen = *cp++;
 1824                         if (verinfo == NULL ||
 1825                             ival == verinfo->md_ver_preferred) {
 1826                                 found = 1;
 1827                                 break;
 1828                         }
 1829                         if (ival >= verinfo->md_ver_minimum &&
 1830                             ival <= verinfo->md_ver_maximum &&
 1831                             ival > bestver) {
 1832                                 bestver = ival;
 1833                                 best = cp;
 1834                                 blen = clen;
 1835                         }
 1836                         break;
 1837                 default:
 1838                         break;
 1839                 }
 1840                 recptr += reclen + sizeof(int);
 1841         }
 1842         /*
 1843          * Finally check if KLD is in the place
 1844          */
 1845         if (found)
 1846                 result = linker_lookup_file(path, pathlen, cp, clen, &mattr);
 1847         else if (best)
 1848                 result = linker_lookup_file(path, pathlen, best, blen, &mattr);
 1849 
 1850         /*
 1851          * KLD is newer than hints file. What we should do now?
 1852          */
 1853         if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >))
 1854                 printf("warning: KLD '%s' is newer than the linker.hints"
 1855                     " file\n", result);
 1856 bad:
 1857         free(pathbuf, M_LINKER);
 1858         if (hints)
 1859                 free(hints, M_TEMP);
 1860         if (nd.ni_vp != NULL) {
 1861                 VOP_UNLOCK(nd.ni_vp, 0);
 1862                 vn_close(nd.ni_vp, FREAD, cred, td);
 1863                 VFS_UNLOCK_GIANT(vfslocked);
 1864         }
 1865         /*
 1866          * If nothing found or hints is absent - fallback to the old
 1867          * way by using "kldname[.ko]" as module name.
 1868          */
 1869         if (!found && !bestver && result == NULL)
 1870                 result = linker_lookup_file(path, pathlen, modname,
 1871                     modnamelen, NULL);
 1872         return (result);
 1873 }
 1874 
 1875 /*
 1876  * Lookup KLD which contains requested module in the all directories.
 1877  */
 1878 static char *
 1879 linker_search_module(const char *modname, int modnamelen,
 1880     struct mod_depend *verinfo)
 1881 {
 1882         char *cp, *ep, *result;
 1883 
 1884         /*
 1885          * traverse the linker path
 1886          */
 1887         for (cp = linker_path; *cp; cp = ep + 1) {
 1888                 /* find the end of this component */
 1889                 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++);
 1890                 result = linker_hints_lookup(cp, ep - cp, modname,
 1891                     modnamelen, verinfo);
 1892                 if (result != NULL)
 1893                         return (result);
 1894                 if (*ep == 0)
 1895                         break;
 1896         }
 1897         return (NULL);
 1898 }
 1899 
 1900 /*
 1901  * Search for module in all directories listed in the linker_path.
 1902  */
 1903 static char *
 1904 linker_search_kld(const char *name)
 1905 {
 1906         char *cp, *ep, *result;
 1907         int len;
 1908 
 1909         /* qualified at all? */
 1910         if (index(name, '/'))
 1911                 return (linker_strdup(name));
 1912 
 1913         /* traverse the linker path */
 1914         len = strlen(name);
 1915         for (ep = linker_path; *ep; ep++) {
 1916                 cp = ep;
 1917                 /* find the end of this component */
 1918                 for (; *ep != 0 && *ep != ';'; ep++);
 1919                 result = linker_lookup_file(cp, ep - cp, name, len, NULL);
 1920                 if (result != NULL)
 1921                         return (result);
 1922         }
 1923         return (NULL);
 1924 }
 1925 
 1926 static const char *
 1927 linker_basename(const char *path)
 1928 {
 1929         const char *filename;
 1930 
 1931         filename = rindex(path, '/');
 1932         if (filename == NULL)
 1933                 return path;
 1934         if (filename[1])
 1935                 filename++;
 1936         return (filename);
 1937 }
 1938 
 1939 #ifdef HWPMC_HOOKS
 1940 /*
 1941  * Inform hwpmc about the set of kernel modules currently loaded.
 1942  */
 1943 void *
 1944 linker_hwpmc_list_objects(void)
 1945 {
 1946         linker_file_t lf;
 1947         struct pmckern_map_in *kobase;
 1948         int i, nmappings;
 1949 
 1950         nmappings = 0;
 1951         KLD_LOCK_READ();
 1952         TAILQ_FOREACH(lf, &linker_files, link)
 1953                 nmappings++;
 1954 
 1955         /* Allocate nmappings + 1 entries. */
 1956         kobase = malloc((nmappings + 1) * sizeof(struct pmckern_map_in),
 1957             M_LINKER, M_WAITOK | M_ZERO);
 1958         i = 0;
 1959         TAILQ_FOREACH(lf, &linker_files, link) {
 1960 
 1961                 /* Save the info for this linker file. */
 1962                 kobase[i].pm_file = lf->filename;
 1963                 kobase[i].pm_address = (uintptr_t)lf->address;
 1964                 i++;
 1965         }
 1966         KLD_UNLOCK_READ();
 1967 
 1968         KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?"));
 1969 
 1970         /* The last entry of the malloced area comprises of all zeros. */
 1971         KASSERT(kobase[i].pm_file == NULL,
 1972             ("linker_hwpmc_list_objects: last object not NULL"));
 1973 
 1974         return ((void *)kobase);
 1975 }
 1976 #endif
 1977 
 1978 /*
 1979  * Find a file which contains given module and load it, if "parent" is not
 1980  * NULL, register a reference to it.
 1981  */
 1982 static int
 1983 linker_load_module(const char *kldname, const char *modname,
 1984     struct linker_file *parent, struct mod_depend *verinfo,
 1985     struct linker_file **lfpp)
 1986 {
 1987         linker_file_t lfdep;
 1988         const char *filename;
 1989         char *pathname;
 1990         int error;
 1991 
 1992         KLD_LOCK_ASSERT();
 1993         if (modname == NULL) {
 1994                 /*
 1995                  * We have to load KLD
 1996                  */
 1997                 KASSERT(verinfo == NULL, ("linker_load_module: verinfo"
 1998                     " is not NULL"));
 1999                 pathname = linker_search_kld(kldname);
 2000         } else {
 2001                 if (modlist_lookup2(modname, verinfo) != NULL)
 2002                         return (EEXIST);
 2003                 if (kldname != NULL)
 2004                         pathname = linker_strdup(kldname);
 2005                 else if (rootvnode == NULL)
 2006                         pathname = NULL;
 2007                 else
 2008                         /*
 2009                          * Need to find a KLD with required module
 2010                          */
 2011                         pathname = linker_search_module(modname,
 2012                             strlen(modname), verinfo);
 2013         }
 2014         if (pathname == NULL)
 2015                 return (ENOENT);
 2016 
 2017         /*
 2018          * Can't load more than one file with the same basename XXX:
 2019          * Actually it should be possible to have multiple KLDs with
 2020          * the same basename but different path because they can
 2021          * provide different versions of the same modules.
 2022          */
 2023         filename = linker_basename(pathname);
 2024         if (linker_find_file_by_name(filename))
 2025                 error = EEXIST;
 2026         else do {
 2027                 error = linker_load_file(pathname, &lfdep);
 2028                 if (error)
 2029                         break;
 2030                 if (modname && verinfo &&
 2031                     modlist_lookup2(modname, verinfo) == NULL) {
 2032                         linker_file_unload(lfdep, LINKER_UNLOAD_FORCE);
 2033                         error = ENOENT;
 2034                         break;
 2035                 }
 2036                 if (parent) {
 2037                         error = linker_file_add_dependency(parent, lfdep);
 2038                         if (error)
 2039                                 break;
 2040                 }
 2041                 if (lfpp)
 2042                         *lfpp = lfdep;
 2043         } while (0);
 2044         free(pathname, M_LINKER);
 2045         return (error);
 2046 }
 2047 
 2048 /*
 2049  * This routine is responsible for finding dependencies of userland initiated
 2050  * kldload(2)'s of files.
 2051  */
 2052 int
 2053 linker_load_dependencies(linker_file_t lf)
 2054 {
 2055         linker_file_t lfdep;
 2056         struct mod_metadata **start, **stop, **mdp, **nmdp;
 2057         struct mod_metadata *mp, *nmp;
 2058         struct mod_depend *verinfo;
 2059         modlist_t mod;
 2060         const char *modname, *nmodname;
 2061         int ver, error = 0, count;
 2062 
 2063         /*
 2064          * All files are dependant on /kernel.
 2065          */
 2066         KLD_LOCK_ASSERT();
 2067         if (linker_kernel_file) {
 2068                 linker_kernel_file->refs++;
 2069                 error = linker_file_add_dependency(lf, linker_kernel_file);
 2070                 if (error)
 2071                         return (error);
 2072         }
 2073         if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop,
 2074             &count) != 0)
 2075                 return (0);
 2076         for (mdp = start; mdp < stop; mdp++) {
 2077                 mp = *mdp;
 2078                 if (mp->md_type != MDT_VERSION)
 2079                         continue;
 2080                 modname = mp->md_cval;
 2081                 ver = ((struct mod_version *)mp->md_data)->mv_version;
 2082                 mod = modlist_lookup(modname, ver);
 2083                 if (mod != NULL) {
 2084                         printf("interface %s.%d already present in the KLD"
 2085                             " '%s'!\n", modname, ver,
 2086                             mod->container->filename);
 2087                         return (EEXIST);
 2088                 }
 2089         }
 2090 
 2091         for (mdp = start; mdp < stop; mdp++) {
 2092                 mp = *mdp;
 2093                 if (mp->md_type != MDT_DEPEND)
 2094                         continue;
 2095                 modname = mp->md_cval;
 2096                 verinfo = mp->md_data;
 2097                 nmodname = NULL;
 2098                 for (nmdp = start; nmdp < stop; nmdp++) {
 2099                         nmp = *nmdp;
 2100                         if (nmp->md_type != MDT_VERSION)
 2101                                 continue;
 2102                         nmodname = nmp->md_cval;
 2103                         if (strcmp(modname, nmodname) == 0)
 2104                                 break;
 2105                 }
 2106                 if (nmdp < stop)/* early exit, it's a self reference */
 2107                         continue;
 2108                 mod = modlist_lookup2(modname, verinfo);
 2109                 if (mod) {      /* woohoo, it's loaded already */
 2110                         lfdep = mod->container;
 2111                         lfdep->refs++;
 2112                         error = linker_file_add_dependency(lf, lfdep);
 2113                         if (error)
 2114                                 break;
 2115                         continue;
 2116                 }
 2117                 error = linker_load_module(NULL, modname, lf, verinfo, NULL);
 2118                 if (error) {
 2119                         printf("KLD %s: depends on %s - not available or"
 2120                             " version mismatch\n", lf->filename, modname);
 2121                         break;
 2122                 }
 2123         }
 2124 
 2125         if (error)
 2126                 return (error);
 2127         linker_addmodules(lf, start, stop, 0);
 2128         return (error);
 2129 }
 2130 
 2131 static int
 2132 sysctl_kern_function_list_iterate(const char *name, void *opaque)
 2133 {
 2134         struct sysctl_req *req;
 2135 
 2136         req = opaque;
 2137         return (SYSCTL_OUT(req, name, strlen(name) + 1));
 2138 }
 2139 
 2140 /*
 2141  * Export a nul-separated, double-nul-terminated list of all function names
 2142  * in the kernel.
 2143  */
 2144 static int
 2145 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS)
 2146 {
 2147         linker_file_t lf;
 2148         int error;
 2149 
 2150 #ifdef MAC
 2151         error = mac_kld_check_stat(req->td->td_ucred);
 2152         if (error)
 2153                 return (error);
 2154 #endif
 2155         error = sysctl_wire_old_buffer(req, 0);
 2156         if (error != 0)
 2157                 return (error);
 2158         KLD_LOCK();
 2159         TAILQ_FOREACH(lf, &linker_files, link) {
 2160                 error = LINKER_EACH_FUNCTION_NAME(lf,
 2161                     sysctl_kern_function_list_iterate, req);
 2162                 if (error) {
 2163                         KLD_UNLOCK();
 2164                         return (error);
 2165                 }
 2166         }
 2167         KLD_UNLOCK();
 2168         return (SYSCTL_OUT(req, "", 1));
 2169 }
 2170 
 2171 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLFLAG_RD,
 2172     NULL, 0, sysctl_kern_function_list, "", "kernel function list");

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