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


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

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

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    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: stable/9/sys/kern/kern_linker.c 264371 2014-04-12 14:18:48Z kib $");
   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/eventhandler.h>
   48 #include <sys/fcntl.h>
   49 #include <sys/jail.h>
   50 #include <sys/libkern.h>
   51 #include <sys/namei.h>
   52 #include <sys/vnode.h>
   53 #include <sys/syscallsubr.h>
   54 #include <sys/sysctl.h>
   55 
   56 #include <net/vnet.h>
   57 
   58 #include <security/mac/mac_framework.h>
   59 
   60 #include "linker_if.h"
   61 
   62 #ifdef HWPMC_HOOKS
   63 #include <sys/pmckern.h>
   64 #endif
   65 
   66 #ifdef KLD_DEBUG
   67 int kld_debug = 0;
   68 SYSCTL_INT(_debug, OID_AUTO, kld_debug, CTLFLAG_RW,
   69         &kld_debug, 0, "Set various levels of KLD debug");
   70 #endif
   71 
   72 /*
   73  * static char *linker_search_path(const char *name, struct mod_depend
   74  * *verinfo);
   75  */
   76 static const char       *linker_basename(const char *path);
   77 
   78 /*
   79  * Find a currently loaded file given its filename.
   80  */
   81 static linker_file_t linker_find_file_by_name(const char* _filename);
   82 
   83 /*
   84  * Find a currently loaded file given its file id.
   85  */
   86 static linker_file_t linker_find_file_by_id(int _fileid);
   87 
   88 /* Metadata from the static kernel */
   89 SET_DECLARE(modmetadata_set, struct mod_metadata);
   90 
   91 MALLOC_DEFINE(M_LINKER, "linker", "kernel linker");
   92 
   93 linker_file_t linker_kernel_file;
   94 
   95 static struct sx kld_sx;        /* kernel linker lock */
   96 
   97 /*
   98  * Load counter used by clients to determine if a linker file has been
   99  * re-loaded. This counter is incremented for each file load.
  100  */
  101 static int loadcnt;
  102 
  103 static linker_class_list_t classes;
  104 static linker_file_list_t linker_files;
  105 static int next_file_id = 1;
  106 static int linker_no_more_classes = 0;
  107 
  108 #define LINKER_GET_NEXT_FILE_ID(a) do {                                 \
  109         linker_file_t lftmp;                                            \
  110                                                                         \
  111         if (!cold)                                                      \
  112                 sx_assert(&kld_sx, SA_XLOCKED);                         \
  113 retry:                                                                  \
  114         TAILQ_FOREACH(lftmp, &linker_files, link) {                     \
  115                 if (next_file_id == lftmp->id) {                        \
  116                         next_file_id++;                                 \
  117                         goto retry;                                     \
  118                 }                                                       \
  119         }                                                               \
  120         (a) = next_file_id;                                             \
  121 } while(0)
  122 
  123 
  124 /* XXX wrong name; we're looking at version provision tags here, not modules */
  125 typedef TAILQ_HEAD(, modlist) modlisthead_t;
  126 struct modlist {
  127         TAILQ_ENTRY(modlist) link;      /* chain together all modules */
  128         linker_file_t   container;
  129         const char      *name;
  130         int             version;
  131 };
  132 typedef struct modlist *modlist_t;
  133 static modlisthead_t found_modules;
  134 
  135 static int      linker_file_add_dependency(linker_file_t file,
  136                     linker_file_t dep);
  137 static caddr_t  linker_file_lookup_symbol_internal(linker_file_t file,
  138                     const char* name, int deps);
  139 static int      linker_load_module(const char *kldname,
  140                     const char *modname, struct linker_file *parent,
  141                     struct mod_depend *verinfo, struct linker_file **lfpp);
  142 static modlist_t modlist_lookup2(const char *name, struct mod_depend *verinfo);
  143 
  144 static char *
  145 linker_strdup(const char *str)
  146 {
  147         char *result;
  148 
  149         if ((result = malloc((strlen(str) + 1), M_LINKER, M_WAITOK)) != NULL)
  150                 strcpy(result, str);
  151         return (result);
  152 }
  153 
  154 static void
  155 linker_init(void *arg)
  156 {
  157 
  158         sx_init(&kld_sx, "kernel linker");
  159         TAILQ_INIT(&classes);
  160         TAILQ_INIT(&linker_files);
  161 }
  162 
  163 SYSINIT(linker, SI_SUB_KLD, SI_ORDER_FIRST, linker_init, 0);
  164 
  165 static void
  166 linker_stop_class_add(void *arg)
  167 {
  168 
  169         linker_no_more_classes = 1;
  170 }
  171 
  172 SYSINIT(linker_class, SI_SUB_KLD, SI_ORDER_ANY, linker_stop_class_add, NULL);
  173 
  174 int
  175 linker_add_class(linker_class_t lc)
  176 {
  177 
  178         /*
  179          * We disallow any class registration past SI_ORDER_ANY
  180          * of SI_SUB_KLD.  We bump the reference count to keep the
  181          * ops from being freed.
  182          */
  183         if (linker_no_more_classes == 1)
  184                 return (EPERM);
  185         kobj_class_compile((kobj_class_t) lc);
  186         ((kobj_class_t)lc)->refs++;     /* XXX: kobj_mtx */
  187         TAILQ_INSERT_TAIL(&classes, lc, link);
  188         return (0);
  189 }
  190 
  191 static void
  192 linker_file_sysinit(linker_file_t lf)
  193 {
  194         struct sysinit **start, **stop, **sipp, **xipp, *save;
  195 
  196         KLD_DPF(FILE, ("linker_file_sysinit: calling SYSINITs for %s\n",
  197             lf->filename));
  198 
  199         sx_assert(&kld_sx, SA_XLOCKED);
  200 
  201         if (linker_file_lookup_set(lf, "sysinit_set", &start, &stop, NULL) != 0)
  202                 return;
  203         /*
  204          * Perform a bubble sort of the system initialization objects by
  205          * their subsystem (primary key) and order (secondary key).
  206          *
  207          * Since some things care about execution order, this is the operation
  208          * which ensures continued function.
  209          */
  210         for (sipp = start; sipp < stop; sipp++) {
  211                 for (xipp = sipp + 1; xipp < stop; xipp++) {
  212                         if ((*sipp)->subsystem < (*xipp)->subsystem ||
  213                             ((*sipp)->subsystem == (*xipp)->subsystem &&
  214                             (*sipp)->order <= (*xipp)->order))
  215                                 continue;       /* skip */
  216                         save = *sipp;
  217                         *sipp = *xipp;
  218                         *xipp = save;
  219                 }
  220         }
  221 
  222         /*
  223          * Traverse the (now) ordered list of system initialization tasks.
  224          * Perform each task, and continue on to the next task.
  225          */
  226         sx_xunlock(&kld_sx);
  227         mtx_lock(&Giant);
  228         for (sipp = start; sipp < stop; sipp++) {
  229                 if ((*sipp)->subsystem == SI_SUB_DUMMY)
  230                         continue;       /* skip dummy task(s) */
  231 
  232                 /* Call function */
  233                 (*((*sipp)->func)) ((*sipp)->udata);
  234         }
  235         mtx_unlock(&Giant);
  236         sx_xlock(&kld_sx);
  237 }
  238 
  239 static void
  240 linker_file_sysuninit(linker_file_t lf)
  241 {
  242         struct sysinit **start, **stop, **sipp, **xipp, *save;
  243 
  244         KLD_DPF(FILE, ("linker_file_sysuninit: calling SYSUNINITs for %s\n",
  245             lf->filename));
  246 
  247         sx_assert(&kld_sx, SA_XLOCKED);
  248 
  249         if (linker_file_lookup_set(lf, "sysuninit_set", &start, &stop,
  250             NULL) != 0)
  251                 return;
  252 
  253         /*
  254          * Perform a reverse bubble sort of the system initialization objects
  255          * by their subsystem (primary key) and order (secondary key).
  256          *
  257          * Since some things care about execution order, this is the operation
  258          * which ensures continued function.
  259          */
  260         for (sipp = start; sipp < stop; sipp++) {
  261                 for (xipp = sipp + 1; xipp < stop; xipp++) {
  262                         if ((*sipp)->subsystem > (*xipp)->subsystem ||
  263                             ((*sipp)->subsystem == (*xipp)->subsystem &&
  264                             (*sipp)->order >= (*xipp)->order))
  265                                 continue;       /* skip */
  266                         save = *sipp;
  267                         *sipp = *xipp;
  268                         *xipp = save;
  269                 }
  270         }
  271 
  272         /*
  273          * Traverse the (now) ordered list of system initialization tasks.
  274          * Perform each task, and continue on to the next task.
  275          */
  276         sx_xunlock(&kld_sx);
  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         sx_xlock(&kld_sx);
  287 }
  288 
  289 static void
  290 linker_file_register_sysctls(linker_file_t lf)
  291 {
  292         struct sysctl_oid **start, **stop, **oidp;
  293 
  294         KLD_DPF(FILE,
  295             ("linker_file_register_sysctls: registering SYSCTLs for %s\n",
  296             lf->filename));
  297 
  298         sx_assert(&kld_sx, SA_XLOCKED);
  299 
  300         if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
  301                 return;
  302 
  303         sx_xunlock(&kld_sx);
  304         sysctl_lock();
  305         for (oidp = start; oidp < stop; oidp++)
  306                 sysctl_register_oid(*oidp);
  307         sysctl_unlock();
  308         sx_xlock(&kld_sx);
  309 }
  310 
  311 static void
  312 linker_file_unregister_sysctls(linker_file_t lf)
  313 {
  314         struct sysctl_oid **start, **stop, **oidp;
  315 
  316         KLD_DPF(FILE, ("linker_file_unregister_sysctls: registering SYSCTLs"
  317             " for %s\n", lf->filename));
  318 
  319         sx_assert(&kld_sx, SA_XLOCKED);
  320 
  321         if (linker_file_lookup_set(lf, "sysctl_set", &start, &stop, NULL) != 0)
  322                 return;
  323 
  324         sx_xunlock(&kld_sx);
  325         sysctl_lock();
  326         for (oidp = start; oidp < stop; oidp++)
  327                 sysctl_unregister_oid(*oidp);
  328         sysctl_unlock();
  329         sx_xlock(&kld_sx);
  330 }
  331 
  332 static int
  333 linker_file_register_modules(linker_file_t lf)
  334 {
  335         struct mod_metadata **start, **stop, **mdp;
  336         const moduledata_t *moddata;
  337         int first_error, error;
  338 
  339         KLD_DPF(FILE, ("linker_file_register_modules: registering modules"
  340             " in %s\n", lf->filename));
  341 
  342         sx_assert(&kld_sx, SA_XLOCKED);
  343 
  344         if (linker_file_lookup_set(lf, "modmetadata_set", &start,
  345             &stop, NULL) != 0) {
  346                 /*
  347                  * This fallback should be unnecessary, but if we get booted
  348                  * from boot2 instead of loader and we are missing our
  349                  * metadata then we have to try the best we can.
  350                  */
  351                 if (lf == linker_kernel_file) {
  352                         start = SET_BEGIN(modmetadata_set);
  353                         stop = SET_LIMIT(modmetadata_set);
  354                 } else
  355                         return (0);
  356         }
  357         first_error = 0;
  358         for (mdp = start; mdp < stop; mdp++) {
  359                 if ((*mdp)->md_type != MDT_MODULE)
  360                         continue;
  361                 moddata = (*mdp)->md_data;
  362                 KLD_DPF(FILE, ("Registering module %s in %s\n",
  363                     moddata->name, lf->filename));
  364                 error = module_register(moddata, lf);
  365                 if (error) {
  366                         printf("Module %s failed to register: %d\n",
  367                             moddata->name, error);
  368                         if (first_error == 0)
  369                                 first_error = error;
  370                 }
  371         }
  372         return (first_error);
  373 }
  374 
  375 static void
  376 linker_init_kernel_modules(void)
  377 {
  378 
  379         sx_xlock(&kld_sx);
  380         linker_file_register_modules(linker_kernel_file);
  381         sx_xunlock(&kld_sx);
  382 }
  383 
  384 SYSINIT(linker_kernel, SI_SUB_KLD, SI_ORDER_ANY, linker_init_kernel_modules,
  385     0);
  386 
  387 static int
  388 linker_load_file(const char *filename, linker_file_t *result)
  389 {
  390         linker_class_t lc;
  391         linker_file_t lf;
  392         int foundfile, error, modules;
  393 
  394         /* Refuse to load modules if securelevel raised */
  395         if (prison0.pr_securelevel > 0)
  396                 return (EPERM);
  397 
  398         sx_assert(&kld_sx, SA_XLOCKED);
  399         lf = linker_find_file_by_name(filename);
  400         if (lf) {
  401                 KLD_DPF(FILE, ("linker_load_file: file %s is already loaded,"
  402                     " incrementing refs\n", filename));
  403                 *result = lf;
  404                 lf->refs++;
  405                 return (0);
  406         }
  407         foundfile = 0;
  408         error = 0;
  409 
  410         /*
  411          * We do not need to protect (lock) classes here because there is
  412          * no class registration past startup (SI_SUB_KLD, SI_ORDER_ANY)
  413          * and there is no class deregistration mechanism at this time.
  414          */
  415         TAILQ_FOREACH(lc, &classes, link) {
  416                 KLD_DPF(FILE, ("linker_load_file: trying to load %s\n",
  417                     filename));
  418                 error = LINKER_LOAD_FILE(lc, filename, &lf);
  419                 /*
  420                  * If we got something other than ENOENT, then it exists but
  421                  * we cannot load it for some other reason.
  422                  */
  423                 if (error != ENOENT)
  424                         foundfile = 1;
  425                 if (lf) {
  426                         error = linker_file_register_modules(lf);
  427                         if (error == EEXIST) {
  428                                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
  429                                 return (error);
  430                         }
  431                         modules = !TAILQ_EMPTY(&lf->modules);
  432                         linker_file_register_sysctls(lf);
  433                         linker_file_sysinit(lf);
  434                         lf->flags |= LINKER_FILE_LINKED;
  435 
  436                         /*
  437                          * If all of the modules in this file failed
  438                          * to load, unload the file and return an
  439                          * error of ENOEXEC.
  440                          */
  441                         if (modules && TAILQ_EMPTY(&lf->modules)) {
  442                                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
  443                                 return (ENOEXEC);
  444                         }
  445                         EVENTHANDLER_INVOKE(kld_load, lf);
  446                         *result = lf;
  447                         return (0);
  448                 }
  449         }
  450         /*
  451          * Less than ideal, but tells the user whether it failed to load or
  452          * the module was not found.
  453          */
  454         if (foundfile) {
  455 
  456                 /*
  457                  * If the file type has not been recognized by the last try
  458                  * printout a message before to fail.
  459                  */
  460                 if (error == ENOSYS)
  461                         printf("linker_load_file: Unsupported file type\n");
  462 
  463                 /*
  464                  * Format not recognized or otherwise unloadable.
  465                  * When loading a module that is statically built into
  466                  * the kernel EEXIST percolates back up as the return
  467                  * value.  Preserve this so that apps like sysinstall
  468                  * can recognize this special case and not post bogus
  469                  * dialog boxes.
  470                  */
  471                 if (error != EEXIST)
  472                         error = ENOEXEC;
  473         } else
  474                 error = ENOENT;         /* Nothing found */
  475         return (error);
  476 }
  477 
  478 int
  479 linker_reference_module(const char *modname, struct mod_depend *verinfo,
  480     linker_file_t *result)
  481 {
  482         modlist_t mod;
  483         int error;
  484 
  485         sx_xlock(&kld_sx);
  486         if ((mod = modlist_lookup2(modname, verinfo)) != NULL) {
  487                 *result = mod->container;
  488                 (*result)->refs++;
  489                 sx_xunlock(&kld_sx);
  490                 return (0);
  491         }
  492 
  493         error = linker_load_module(NULL, modname, NULL, verinfo, result);
  494         sx_xunlock(&kld_sx);
  495         return (error);
  496 }
  497 
  498 int
  499 linker_release_module(const char *modname, struct mod_depend *verinfo,
  500     linker_file_t lf)
  501 {
  502         modlist_t mod;
  503         int error;
  504 
  505         sx_xlock(&kld_sx);
  506         if (lf == NULL) {
  507                 KASSERT(modname != NULL,
  508                     ("linker_release_module: no file or name"));
  509                 mod = modlist_lookup2(modname, verinfo);
  510                 if (mod == NULL) {
  511                         sx_xunlock(&kld_sx);
  512                         return (ESRCH);
  513                 }
  514                 lf = mod->container;
  515         } else
  516                 KASSERT(modname == NULL && verinfo == NULL,
  517                     ("linker_release_module: both file and name"));
  518         error = linker_file_unload(lf, LINKER_UNLOAD_NORMAL);
  519         sx_xunlock(&kld_sx);
  520         return (error);
  521 }
  522 
  523 static linker_file_t
  524 linker_find_file_by_name(const char *filename)
  525 {
  526         linker_file_t lf;
  527         char *koname;
  528 
  529         koname = malloc(strlen(filename) + 4, M_LINKER, M_WAITOK);
  530         sprintf(koname, "%s.ko", filename);
  531 
  532         sx_assert(&kld_sx, SA_XLOCKED);
  533         TAILQ_FOREACH(lf, &linker_files, link) {
  534                 if (strcmp(lf->filename, koname) == 0)
  535                         break;
  536                 if (strcmp(lf->filename, filename) == 0)
  537                         break;
  538         }
  539         free(koname, M_LINKER);
  540         return (lf);
  541 }
  542 
  543 static linker_file_t
  544 linker_find_file_by_id(int fileid)
  545 {
  546         linker_file_t lf;
  547 
  548         sx_assert(&kld_sx, SA_XLOCKED);
  549         TAILQ_FOREACH(lf, &linker_files, link)
  550                 if (lf->id == fileid && lf->flags & LINKER_FILE_LINKED)
  551                         break;
  552         return (lf);
  553 }
  554 
  555 int
  556 linker_file_foreach(linker_predicate_t *predicate, void *context)
  557 {
  558         linker_file_t lf;
  559         int retval = 0;
  560 
  561         sx_xlock(&kld_sx);
  562         TAILQ_FOREACH(lf, &linker_files, link) {
  563                 retval = predicate(lf, context);
  564                 if (retval != 0)
  565                         break;
  566         }
  567         sx_xunlock(&kld_sx);
  568         return (retval);
  569 }
  570 
  571 linker_file_t
  572 linker_make_file(const char *pathname, linker_class_t lc)
  573 {
  574         linker_file_t lf;
  575         const char *filename;
  576 
  577         if (!cold)
  578                 sx_assert(&kld_sx, SA_XLOCKED);
  579         filename = linker_basename(pathname);
  580 
  581         KLD_DPF(FILE, ("linker_make_file: new file, filename='%s' for pathname='%s'\n", filename, pathname));
  582         lf = (linker_file_t)kobj_create((kobj_class_t)lc, M_LINKER, M_WAITOK);
  583         if (lf == NULL)
  584                 return (NULL);
  585         lf->refs = 1;
  586         lf->userrefs = 0;
  587         lf->flags = 0;
  588         lf->filename = linker_strdup(filename);
  589         lf->pathname = linker_strdup(pathname);
  590         LINKER_GET_NEXT_FILE_ID(lf->id);
  591         lf->ndeps = 0;
  592         lf->deps = NULL;
  593         lf->loadcnt = ++loadcnt;
  594         STAILQ_INIT(&lf->common);
  595         TAILQ_INIT(&lf->modules);
  596         TAILQ_INSERT_TAIL(&linker_files, lf, link);
  597         return (lf);
  598 }
  599 
  600 int
  601 linker_file_unload(linker_file_t file, int flags)
  602 {
  603         module_t mod, next;
  604         modlist_t ml, nextml;
  605         struct common_symbol *cp;
  606         int error, i;
  607 
  608         /* Refuse to unload modules if securelevel raised. */
  609         if (prison0.pr_securelevel > 0)
  610                 return (EPERM);
  611 
  612         sx_assert(&kld_sx, SA_XLOCKED);
  613         KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));
  614 
  615         /* Easy case of just dropping a reference. */
  616         if (file->refs > 1) {
  617                 file->refs--;
  618                 return (0);
  619         }
  620 
  621         /* Give eventhandlers a chance to prevent the unload. */
  622         error = 0;
  623         EVENTHANDLER_INVOKE(kld_unload_try, file, &error);
  624         if (error != 0)
  625                 return (EBUSY);
  626 
  627         KLD_DPF(FILE, ("linker_file_unload: file is unloading,"
  628             " informing modules\n"));
  629 
  630         /*
  631          * Quiesce all the modules to give them a chance to veto the unload.
  632          */
  633         MOD_SLOCK;
  634         for (mod = TAILQ_FIRST(&file->modules); mod;
  635              mod = module_getfnext(mod)) {
  636 
  637                 error = module_quiesce(mod);
  638                 if (error != 0 && flags != LINKER_UNLOAD_FORCE) {
  639                         KLD_DPF(FILE, ("linker_file_unload: module %s"
  640                             " vetoed unload\n", module_getname(mod)));
  641                         /*
  642                          * XXX: Do we need to tell all the quiesced modules
  643                          * that they can resume work now via a new module
  644                          * event?
  645                          */
  646                         MOD_SUNLOCK;
  647                         return (error);
  648                 }
  649         }
  650         MOD_SUNLOCK;
  651 
  652         /*
  653          * Inform any modules associated with this file that they are
  654          * being unloaded.
  655          */
  656         MOD_XLOCK;
  657         for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
  658                 next = module_getfnext(mod);
  659                 MOD_XUNLOCK;
  660 
  661                 /*
  662                  * Give the module a chance to veto the unload.
  663                  */
  664                 if ((error = module_unload(mod)) != 0) {
  665 #ifdef KLD_DEBUG
  666                         MOD_SLOCK;
  667                         KLD_DPF(FILE, ("linker_file_unload: module %s"
  668                             " failed unload\n", module_getname(mod)));
  669                         MOD_SUNLOCK;
  670 #endif
  671                         return (error);
  672                 }
  673                 MOD_XLOCK;
  674                 module_release(mod);
  675         }
  676         MOD_XUNLOCK;
  677 
  678         TAILQ_FOREACH_SAFE(ml, &found_modules, link, nextml) {
  679                 if (ml->container == file) {
  680                         TAILQ_REMOVE(&found_modules, ml, link);
  681                         free(ml, M_LINKER);
  682                 }
  683         }
  684 
  685         /*
  686          * Don't try to run SYSUNINITs if we are unloaded due to a
  687          * link error.
  688          */
  689         if (file->flags & LINKER_FILE_LINKED) {
  690                 file->flags &= ~LINKER_FILE_LINKED;
  691                 linker_file_sysuninit(file);
  692                 linker_file_unregister_sysctls(file);
  693         }
  694         TAILQ_REMOVE(&linker_files, file, link);
  695 
  696         if (file->deps) {
  697                 for (i = 0; i < file->ndeps; i++)
  698                         linker_file_unload(file->deps[i], flags);
  699                 free(file->deps, M_LINKER);
  700                 file->deps = NULL;
  701         }
  702         while ((cp = STAILQ_FIRST(&file->common)) != NULL) {
  703                 STAILQ_REMOVE_HEAD(&file->common, link);
  704                 free(cp, M_LINKER);
  705         }
  706 
  707         LINKER_UNLOAD(file);
  708 
  709         EVENTHANDLER_INVOKE(kld_unload, file->filename, file->address,
  710             file->size);
  711 
  712         if (file->filename) {
  713                 free(file->filename, M_LINKER);
  714                 file->filename = NULL;
  715         }
  716         if (file->pathname) {
  717                 free(file->pathname, M_LINKER);
  718                 file->pathname = NULL;
  719         }
  720         kobj_delete((kobj_t) file, M_LINKER);
  721         return (0);
  722 }
  723 
  724 int
  725 linker_ctf_get(linker_file_t file, linker_ctf_t *lc)
  726 {
  727         return (LINKER_CTF_GET(file, lc));
  728 }
  729 
  730 static int
  731 linker_file_add_dependency(linker_file_t file, linker_file_t dep)
  732 {
  733         linker_file_t *newdeps;
  734 
  735         sx_assert(&kld_sx, SA_XLOCKED);
  736         file->deps = realloc(file->deps, (file->ndeps + 1) * sizeof(*newdeps),
  737             M_LINKER, M_WAITOK | M_ZERO);
  738         file->deps[file->ndeps] = dep;
  739         file->ndeps++;
  740         KLD_DPF(FILE, ("linker_file_add_dependency:"
  741             " adding %s as dependency for %s\n", 
  742             dep->filename, file->filename));
  743         return (0);
  744 }
  745 
  746 /*
  747  * Locate a linker set and its contents.  This is a helper function to avoid
  748  * linker_if.h exposure elsewhere.  Note: firstp and lastp are really void **.
  749  * This function is used in this file so we can avoid having lots of (void **)
  750  * casts.
  751  */
  752 int
  753 linker_file_lookup_set(linker_file_t file, const char *name,
  754     void *firstp, void *lastp, int *countp)
  755 {
  756 
  757         sx_assert(&kld_sx, SA_LOCKED);
  758         return (LINKER_LOOKUP_SET(file, name, firstp, lastp, countp));
  759 }
  760 
  761 /*
  762  * List all functions in a file.
  763  */
  764 int
  765 linker_file_function_listall(linker_file_t lf,
  766     linker_function_nameval_callback_t callback_func, void *arg)
  767 {
  768         return (LINKER_EACH_FUNCTION_NAMEVAL(lf, callback_func, arg));
  769 }
  770 
  771 caddr_t
  772 linker_file_lookup_symbol(linker_file_t file, const char *name, int deps)
  773 {
  774         caddr_t sym;
  775         int locked;
  776 
  777         locked = sx_xlocked(&kld_sx);
  778         if (!locked)
  779                 sx_xlock(&kld_sx);
  780         sym = linker_file_lookup_symbol_internal(file, name, deps);
  781         if (!locked)
  782                 sx_xunlock(&kld_sx);
  783         return (sym);
  784 }
  785 
  786 static caddr_t
  787 linker_file_lookup_symbol_internal(linker_file_t file, const char *name,
  788     int deps)
  789 {
  790         c_linker_sym_t sym;
  791         linker_symval_t symval;
  792         caddr_t address;
  793         size_t common_size = 0;
  794         int i;
  795 
  796         sx_assert(&kld_sx, SA_XLOCKED);
  797         KLD_DPF(SYM, ("linker_file_lookup_symbol: file=%p, name=%s, deps=%d\n",
  798             file, name, deps));
  799 
  800         if (LINKER_LOOKUP_SYMBOL(file, name, &sym) == 0) {
  801                 LINKER_SYMBOL_VALUES(file, sym, &symval);
  802                 if (symval.value == 0)
  803                         /*
  804                          * For commons, first look them up in the
  805                          * dependencies and only allocate space if not found
  806                          * there.
  807                          */
  808                         common_size = symval.size;
  809                 else {
  810                         KLD_DPF(SYM, ("linker_file_lookup_symbol: symbol"
  811                             ".value=%p\n", symval.value));
  812                         return (symval.value);
  813                 }
  814         }
  815         if (deps) {
  816                 for (i = 0; i < file->ndeps; i++) {
  817                         address = linker_file_lookup_symbol_internal(
  818                             file->deps[i], name, 0);
  819                         if (address) {
  820                                 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
  821                                     " deps value=%p\n", address));
  822                                 return (address);
  823                         }
  824                 }
  825         }
  826         if (common_size > 0) {
  827                 /*
  828                  * This is a common symbol which was not found in the
  829                  * dependencies.  We maintain a simple common symbol table in
  830                  * the file object.
  831                  */
  832                 struct common_symbol *cp;
  833 
  834                 STAILQ_FOREACH(cp, &file->common, link) {
  835                         if (strcmp(cp->name, name) == 0) {
  836                                 KLD_DPF(SYM, ("linker_file_lookup_symbol:"
  837                                     " old common value=%p\n", cp->address));
  838                                 return (cp->address);
  839                         }
  840                 }
  841                 /*
  842                  * Round the symbol size up to align.
  843                  */
  844                 common_size = (common_size + sizeof(int) - 1) & -sizeof(int);
  845                 cp = malloc(sizeof(struct common_symbol)
  846                     + common_size + strlen(name) + 1, M_LINKER,
  847                     M_WAITOK | M_ZERO);
  848                 cp->address = (caddr_t)(cp + 1);
  849                 cp->name = cp->address + common_size;
  850                 strcpy(cp->name, name);
  851                 bzero(cp->address, common_size);
  852                 STAILQ_INSERT_TAIL(&file->common, cp, link);
  853 
  854                 KLD_DPF(SYM, ("linker_file_lookup_symbol: new common"
  855                     " value=%p\n", cp->address));
  856                 return (cp->address);
  857         }
  858         KLD_DPF(SYM, ("linker_file_lookup_symbol: fail\n"));
  859         return (0);
  860 }
  861 
  862 /*
  863  * Both DDB and stack(9) rely on the kernel linker to provide forward and
  864  * backward lookup of symbols.  However, DDB and sometimes stack(9) need to
  865  * do this in a lockfree manner.  We provide a set of internal helper
  866  * routines to perform these operations without locks, and then wrappers that
  867  * optionally lock.
  868  *
  869  * linker_debug_lookup() is ifdef DDB as currently it's only used by DDB.
  870  */
  871 #ifdef DDB
  872 static int
  873 linker_debug_lookup(const char *symstr, c_linker_sym_t *sym)
  874 {
  875         linker_file_t lf;
  876 
  877         TAILQ_FOREACH(lf, &linker_files, link) {
  878                 if (LINKER_LOOKUP_SYMBOL(lf, symstr, sym) == 0)
  879                         return (0);
  880         }
  881         return (ENOENT);
  882 }
  883 #endif
  884 
  885 static int
  886 linker_debug_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
  887 {
  888         linker_file_t lf;
  889         c_linker_sym_t best, es;
  890         u_long diff, bestdiff, off;
  891 
  892         best = 0;
  893         off = (uintptr_t)value;
  894         bestdiff = off;
  895         TAILQ_FOREACH(lf, &linker_files, link) {
  896                 if (LINKER_SEARCH_SYMBOL(lf, value, &es, &diff) != 0)
  897                         continue;
  898                 if (es != 0 && diff < bestdiff) {
  899                         best = es;
  900                         bestdiff = diff;
  901                 }
  902                 if (bestdiff == 0)
  903                         break;
  904         }
  905         if (best) {
  906                 *sym = best;
  907                 *diffp = bestdiff;
  908                 return (0);
  909         } else {
  910                 *sym = 0;
  911                 *diffp = off;
  912                 return (ENOENT);
  913         }
  914 }
  915 
  916 static int
  917 linker_debug_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
  918 {
  919         linker_file_t lf;
  920 
  921         TAILQ_FOREACH(lf, &linker_files, link) {
  922                 if (LINKER_SYMBOL_VALUES(lf, sym, symval) == 0)
  923                         return (0);
  924         }
  925         return (ENOENT);
  926 }
  927 
  928 static int
  929 linker_debug_search_symbol_name(caddr_t value, char *buf, u_int buflen,
  930     long *offset)
  931 {
  932         linker_symval_t symval;
  933         c_linker_sym_t sym;
  934         int error;
  935 
  936         *offset = 0;
  937         error = linker_debug_search_symbol(value, &sym, offset);
  938         if (error)
  939                 return (error);
  940         error = linker_debug_symbol_values(sym, &symval);
  941         if (error)
  942                 return (error);
  943         strlcpy(buf, symval.name, buflen);
  944         return (0);
  945 }
  946 
  947 /*
  948  * DDB Helpers.  DDB has to look across multiple files with their own symbol
  949  * tables and string tables.
  950  *
  951  * Note that we do not obey list locking protocols here.  We really don't need
  952  * DDB to hang because somebody's got the lock held.  We'll take the chance
  953  * that the files list is inconsistant instead.
  954  */
  955 #ifdef DDB
  956 int
  957 linker_ddb_lookup(const char *symstr, c_linker_sym_t *sym)
  958 {
  959 
  960         return (linker_debug_lookup(symstr, sym));
  961 }
  962 #endif
  963 
  964 int
  965 linker_ddb_search_symbol(caddr_t value, c_linker_sym_t *sym, long *diffp)
  966 {
  967 
  968         return (linker_debug_search_symbol(value, sym, diffp));
  969 }
  970 
  971 int
  972 linker_ddb_symbol_values(c_linker_sym_t sym, linker_symval_t *symval)
  973 {
  974 
  975         return (linker_debug_symbol_values(sym, symval));
  976 }
  977 
  978 int
  979 linker_ddb_search_symbol_name(caddr_t value, char *buf, u_int buflen,
  980     long *offset)
  981 {
  982 
  983         return (linker_debug_search_symbol_name(value, buf, buflen, offset));
  984 }
  985 
  986 /*
  987  * stack(9) helper for non-debugging environemnts.  Unlike DDB helpers, we do
  988  * obey locking protocols, and offer a significantly less complex interface.
  989  */
  990 int
  991 linker_search_symbol_name(caddr_t value, char *buf, u_int buflen,
  992     long *offset)
  993 {
  994         int error;
  995 
  996         sx_xlock(&kld_sx);
  997         error = linker_debug_search_symbol_name(value, buf, buflen, offset);
  998         sx_xunlock(&kld_sx);
  999         return (error);
 1000 }
 1001 
 1002 /*
 1003  * Syscalls.
 1004  */
 1005 int
 1006 kern_kldload(struct thread *td, const char *file, int *fileid)
 1007 {
 1008         const char *kldname, *modname;
 1009         linker_file_t lf;
 1010         int error;
 1011 
 1012         if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
 1013                 return (error);
 1014 
 1015         if ((error = priv_check(td, PRIV_KLD_LOAD)) != 0)
 1016                 return (error);
 1017 
 1018         /*
 1019          * It is possible that kldloaded module will attach a new ifnet,
 1020          * so vnet context must be set when this ocurs.
 1021          */
 1022         CURVNET_SET(TD_TO_VNET(td));
 1023 
 1024         /*
 1025          * If file does not contain a qualified name or any dot in it
 1026          * (kldname.ko, or kldname.ver.ko) treat it as an interface
 1027          * name.
 1028          */
 1029         if (index(file, '/') || index(file, '.')) {
 1030                 kldname = file;
 1031                 modname = NULL;
 1032         } else {
 1033                 kldname = NULL;
 1034                 modname = file;
 1035         }
 1036 
 1037         sx_xlock(&kld_sx);
 1038         error = linker_load_module(kldname, modname, NULL, NULL, &lf);
 1039         if (error) {
 1040                 sx_xunlock(&kld_sx);
 1041                 goto done;
 1042         }
 1043         lf->userrefs++;
 1044         if (fileid != NULL)
 1045                 *fileid = lf->id;
 1046         sx_xunlock(&kld_sx);
 1047 
 1048 done:
 1049         CURVNET_RESTORE();
 1050         return (error);
 1051 }
 1052 
 1053 int
 1054 sys_kldload(struct thread *td, struct kldload_args *uap)
 1055 {
 1056         char *pathname = NULL;
 1057         int error, fileid;
 1058 
 1059         td->td_retval[0] = -1;
 1060 
 1061         pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
 1062         error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL);
 1063         if (error == 0) {
 1064                 error = kern_kldload(td, pathname, &fileid);
 1065                 if (error == 0)
 1066                         td->td_retval[0] = fileid;
 1067         }
 1068         free(pathname, M_TEMP);
 1069         return (error);
 1070 }
 1071 
 1072 int
 1073 kern_kldunload(struct thread *td, int fileid, int flags)
 1074 {
 1075         linker_file_t lf;
 1076         int error = 0;
 1077 
 1078         if ((error = securelevel_gt(td->td_ucred, 0)) != 0)
 1079                 return (error);
 1080 
 1081         if ((error = priv_check(td, PRIV_KLD_UNLOAD)) != 0)
 1082                 return (error);
 1083 
 1084         CURVNET_SET(TD_TO_VNET(td));
 1085         sx_xlock(&kld_sx);
 1086         lf = linker_find_file_by_id(fileid);
 1087         if (lf) {
 1088                 KLD_DPF(FILE, ("kldunload: lf->userrefs=%d\n", lf->userrefs));
 1089 
 1090                 if (lf->userrefs == 0) {
 1091                         /*
 1092                          * XXX: maybe LINKER_UNLOAD_FORCE should override ?
 1093                          */
 1094                         printf("kldunload: attempt to unload file that was"
 1095                             " loaded by the kernel\n");
 1096                         error = EBUSY;
 1097                 } else {
 1098                         lf->userrefs--;
 1099                         error = linker_file_unload(lf, flags);
 1100                         if (error)
 1101                                 lf->userrefs++;
 1102                 }
 1103         } else
 1104                 error = ENOENT;
 1105         sx_xunlock(&kld_sx);
 1106 
 1107         CURVNET_RESTORE();
 1108         return (error);
 1109 }
 1110 
 1111 int
 1112 sys_kldunload(struct thread *td, struct kldunload_args *uap)
 1113 {
 1114 
 1115         return (kern_kldunload(td, uap->fileid, LINKER_UNLOAD_NORMAL));
 1116 }
 1117 
 1118 int
 1119 sys_kldunloadf(struct thread *td, struct kldunloadf_args *uap)
 1120 {
 1121 
 1122         if (uap->flags != LINKER_UNLOAD_NORMAL &&
 1123             uap->flags != LINKER_UNLOAD_FORCE)
 1124                 return (EINVAL);
 1125         return (kern_kldunload(td, uap->fileid, uap->flags));
 1126 }
 1127 
 1128 int
 1129 sys_kldfind(struct thread *td, struct kldfind_args *uap)
 1130 {
 1131         char *pathname;
 1132         const char *filename;
 1133         linker_file_t lf;
 1134         int error;
 1135 
 1136 #ifdef MAC
 1137         error = mac_kld_check_stat(td->td_ucred);
 1138         if (error)
 1139                 return (error);
 1140 #endif
 1141 
 1142         td->td_retval[0] = -1;
 1143 
 1144         pathname = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
 1145         if ((error = copyinstr(uap->file, pathname, MAXPATHLEN, NULL)) != 0)
 1146                 goto out;
 1147 
 1148         filename = linker_basename(pathname);
 1149         sx_xlock(&kld_sx);
 1150         lf = linker_find_file_by_name(filename);
 1151         if (lf)
 1152                 td->td_retval[0] = lf->id;
 1153         else
 1154                 error = ENOENT;
 1155         sx_xunlock(&kld_sx);
 1156 out:
 1157         free(pathname, M_TEMP);
 1158         return (error);
 1159 }
 1160 
 1161 int
 1162 sys_kldnext(struct thread *td, struct kldnext_args *uap)
 1163 {
 1164         linker_file_t lf;
 1165         int error = 0;
 1166 
 1167 #ifdef MAC
 1168         error = mac_kld_check_stat(td->td_ucred);
 1169         if (error)
 1170                 return (error);
 1171 #endif
 1172 
 1173         sx_xlock(&kld_sx);
 1174         if (uap->fileid == 0)
 1175                 lf = TAILQ_FIRST(&linker_files);
 1176         else {
 1177                 lf = linker_find_file_by_id(uap->fileid);
 1178                 if (lf == NULL) {
 1179                         error = ENOENT;
 1180                         goto out;
 1181                 }
 1182                 lf = TAILQ_NEXT(lf, link);
 1183         }
 1184 
 1185         /* Skip partially loaded files. */
 1186         while (lf != NULL && !(lf->flags & LINKER_FILE_LINKED))
 1187                 lf = TAILQ_NEXT(lf, link);
 1188 
 1189         if (lf)
 1190                 td->td_retval[0] = lf->id;
 1191         else
 1192                 td->td_retval[0] = 0;
 1193 out:
 1194         sx_xunlock(&kld_sx);
 1195         return (error);
 1196 }
 1197 
 1198 int
 1199 sys_kldstat(struct thread *td, struct kldstat_args *uap)
 1200 {
 1201         struct kld_file_stat stat;
 1202         int error, version;
 1203 
 1204         /*
 1205          * Check the version of the user's structure.
 1206          */
 1207         if ((error = copyin(&uap->stat->version, &version, sizeof(version)))
 1208             != 0)
 1209                 return (error);
 1210         if (version != sizeof(struct kld_file_stat_1) &&
 1211             version != sizeof(struct kld_file_stat))
 1212                 return (EINVAL);
 1213 
 1214         error = kern_kldstat(td, uap->fileid, &stat);
 1215         if (error != 0)
 1216                 return (error);
 1217         return (copyout(&stat, uap->stat, version));
 1218 }
 1219 
 1220 int
 1221 kern_kldstat(struct thread *td, int fileid, struct kld_file_stat *stat)
 1222 {
 1223         linker_file_t lf;
 1224         int namelen;
 1225 #ifdef MAC
 1226         int error;
 1227 
 1228         error = mac_kld_check_stat(td->td_ucred);
 1229         if (error)
 1230                 return (error);
 1231 #endif
 1232 
 1233         sx_xlock(&kld_sx);
 1234         lf = linker_find_file_by_id(fileid);
 1235         if (lf == NULL) {
 1236                 sx_xunlock(&kld_sx);
 1237                 return (ENOENT);
 1238         }
 1239 
 1240         /* Version 1 fields: */
 1241         namelen = strlen(lf->filename) + 1;
 1242         if (namelen > MAXPATHLEN)
 1243                 namelen = MAXPATHLEN;
 1244         bcopy(lf->filename, &stat->name[0], namelen);
 1245         stat->refs = lf->refs;
 1246         stat->id = lf->id;
 1247         stat->address = lf->address;
 1248         stat->size = lf->size;
 1249         /* Version 2 fields: */
 1250         namelen = strlen(lf->pathname) + 1;
 1251         if (namelen > MAXPATHLEN)
 1252                 namelen = MAXPATHLEN;
 1253         bcopy(lf->pathname, &stat->pathname[0], namelen);
 1254         sx_xunlock(&kld_sx);
 1255 
 1256         td->td_retval[0] = 0;
 1257         return (0);
 1258 }
 1259 
 1260 int
 1261 sys_kldfirstmod(struct thread *td, struct kldfirstmod_args *uap)
 1262 {
 1263         linker_file_t lf;
 1264         module_t mp;
 1265         int error = 0;
 1266 
 1267 #ifdef MAC
 1268         error = mac_kld_check_stat(td->td_ucred);
 1269         if (error)
 1270                 return (error);
 1271 #endif
 1272 
 1273         sx_xlock(&kld_sx);
 1274         lf = linker_find_file_by_id(uap->fileid);
 1275         if (lf) {
 1276                 MOD_SLOCK;
 1277                 mp = TAILQ_FIRST(&lf->modules);
 1278                 if (mp != NULL)
 1279                         td->td_retval[0] = module_getid(mp);
 1280                 else
 1281                         td->td_retval[0] = 0;
 1282                 MOD_SUNLOCK;
 1283         } else
 1284                 error = ENOENT;
 1285         sx_xunlock(&kld_sx);
 1286         return (error);
 1287 }
 1288 
 1289 int
 1290 sys_kldsym(struct thread *td, struct kldsym_args *uap)
 1291 {
 1292         char *symstr = NULL;
 1293         c_linker_sym_t sym;
 1294         linker_symval_t symval;
 1295         linker_file_t lf;
 1296         struct kld_sym_lookup lookup;
 1297         int error = 0;
 1298 
 1299 #ifdef MAC
 1300         error = mac_kld_check_stat(td->td_ucred);
 1301         if (error)
 1302                 return (error);
 1303 #endif
 1304 
 1305         if ((error = copyin(uap->data, &lookup, sizeof(lookup))) != 0)
 1306                 return (error);
 1307         if (lookup.version != sizeof(lookup) ||
 1308             uap->cmd != KLDSYM_LOOKUP)
 1309                 return (EINVAL);
 1310         symstr = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
 1311         if ((error = copyinstr(lookup.symname, symstr, MAXPATHLEN, NULL)) != 0)
 1312                 goto out;
 1313         sx_xlock(&kld_sx);
 1314         if (uap->fileid != 0) {
 1315                 lf = linker_find_file_by_id(uap->fileid);
 1316                 if (lf == NULL)
 1317                         error = ENOENT;
 1318                 else if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
 1319                     LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
 1320                         lookup.symvalue = (uintptr_t) symval.value;
 1321                         lookup.symsize = symval.size;
 1322                         error = copyout(&lookup, uap->data, sizeof(lookup));
 1323                 } else
 1324                         error = ENOENT;
 1325         } else {
 1326                 TAILQ_FOREACH(lf, &linker_files, link) {
 1327                         if (LINKER_LOOKUP_SYMBOL(lf, symstr, &sym) == 0 &&
 1328                             LINKER_SYMBOL_VALUES(lf, sym, &symval) == 0) {
 1329                                 lookup.symvalue = (uintptr_t)symval.value;
 1330                                 lookup.symsize = symval.size;
 1331                                 error = copyout(&lookup, uap->data,
 1332                                     sizeof(lookup));
 1333                                 break;
 1334                         }
 1335                 }
 1336                 if (lf == NULL)
 1337                         error = ENOENT;
 1338         }
 1339         sx_xunlock(&kld_sx);
 1340 out:
 1341         free(symstr, M_TEMP);
 1342         return (error);
 1343 }
 1344 
 1345 /*
 1346  * Preloaded module support
 1347  */
 1348 
 1349 static modlist_t
 1350 modlist_lookup(const char *name, int ver)
 1351 {
 1352         modlist_t mod;
 1353 
 1354         TAILQ_FOREACH(mod, &found_modules, link) {
 1355                 if (strcmp(mod->name, name) == 0 &&
 1356                     (ver == 0 || mod->version == ver))
 1357                         return (mod);
 1358         }
 1359         return (NULL);
 1360 }
 1361 
 1362 static modlist_t
 1363 modlist_lookup2(const char *name, struct mod_depend *verinfo)
 1364 {
 1365         modlist_t mod, bestmod;
 1366         int ver;
 1367 
 1368         if (verinfo == NULL)
 1369                 return (modlist_lookup(name, 0));
 1370         bestmod = NULL;
 1371         TAILQ_FOREACH(mod, &found_modules, link) {
 1372                 if (strcmp(mod->name, name) != 0)
 1373                         continue;
 1374                 ver = mod->version;
 1375                 if (ver == verinfo->md_ver_preferred)
 1376                         return (mod);
 1377                 if (ver >= verinfo->md_ver_minimum &&
 1378                     ver <= verinfo->md_ver_maximum &&
 1379                     (bestmod == NULL || ver > bestmod->version))
 1380                         bestmod = mod;
 1381         }
 1382         return (bestmod);
 1383 }
 1384 
 1385 static modlist_t
 1386 modlist_newmodule(const char *modname, int version, linker_file_t container)
 1387 {
 1388         modlist_t mod;
 1389 
 1390         mod = malloc(sizeof(struct modlist), M_LINKER, M_NOWAIT | M_ZERO);
 1391         if (mod == NULL)
 1392                 panic("no memory for module list");
 1393         mod->container = container;
 1394         mod->name = modname;
 1395         mod->version = version;
 1396         TAILQ_INSERT_TAIL(&found_modules, mod, link);
 1397         return (mod);
 1398 }
 1399 
 1400 static void
 1401 linker_addmodules(linker_file_t lf, struct mod_metadata **start,
 1402     struct mod_metadata **stop, int preload)
 1403 {
 1404         struct mod_metadata *mp, **mdp;
 1405         const char *modname;
 1406         int ver;
 1407 
 1408         for (mdp = start; mdp < stop; mdp++) {
 1409                 mp = *mdp;
 1410                 if (mp->md_type != MDT_VERSION)
 1411                         continue;
 1412                 modname = mp->md_cval;
 1413                 ver = ((struct mod_version *)mp->md_data)->mv_version;
 1414                 if (modlist_lookup(modname, ver) != NULL) {
 1415                         printf("module %s already present!\n", modname);
 1416                         /* XXX what can we do? this is a build error. :-( */
 1417                         continue;
 1418                 }
 1419                 modlist_newmodule(modname, ver, lf);
 1420         }
 1421 }
 1422 
 1423 static void
 1424 linker_preload(void *arg)
 1425 {
 1426         caddr_t modptr;
 1427         const char *modname, *nmodname;
 1428         char *modtype;
 1429         linker_file_t lf, nlf;
 1430         linker_class_t lc;
 1431         int error;
 1432         linker_file_list_t loaded_files;
 1433         linker_file_list_t depended_files;
 1434         struct mod_metadata *mp, *nmp;
 1435         struct mod_metadata **start, **stop, **mdp, **nmdp;
 1436         struct mod_depend *verinfo;
 1437         int nver;
 1438         int resolves;
 1439         modlist_t mod;
 1440         struct sysinit **si_start, **si_stop;
 1441 
 1442         TAILQ_INIT(&loaded_files);
 1443         TAILQ_INIT(&depended_files);
 1444         TAILQ_INIT(&found_modules);
 1445         error = 0;
 1446 
 1447         modptr = NULL;
 1448         sx_xlock(&kld_sx);
 1449         while ((modptr = preload_search_next_name(modptr)) != NULL) {
 1450                 modname = (char *)preload_search_info(modptr, MODINFO_NAME);
 1451                 modtype = (char *)preload_search_info(modptr, MODINFO_TYPE);
 1452                 if (modname == NULL) {
 1453                         printf("Preloaded module at %p does not have a"
 1454                             " name!\n", modptr);
 1455                         continue;
 1456                 }
 1457                 if (modtype == NULL) {
 1458                         printf("Preloaded module at %p does not have a type!\n",
 1459                             modptr);
 1460                         continue;
 1461                 }
 1462                 if (bootverbose)
 1463                         printf("Preloaded %s \"%s\" at %p.\n", modtype, modname,
 1464                             modptr);
 1465                 lf = NULL;
 1466                 TAILQ_FOREACH(lc, &classes, link) {
 1467                         error = LINKER_LINK_PRELOAD(lc, modname, &lf);
 1468                         if (!error)
 1469                                 break;
 1470                         lf = NULL;
 1471                 }
 1472                 if (lf)
 1473                         TAILQ_INSERT_TAIL(&loaded_files, lf, loaded);
 1474         }
 1475 
 1476         /*
 1477          * First get a list of stuff in the kernel.
 1478          */
 1479         if (linker_file_lookup_set(linker_kernel_file, MDT_SETNAME, &start,
 1480             &stop, NULL) == 0)
 1481                 linker_addmodules(linker_kernel_file, start, stop, 1);
 1482 
 1483         /*
 1484          * This is a once-off kinky bubble sort to resolve relocation
 1485          * dependency requirements.
 1486          */
 1487 restart:
 1488         TAILQ_FOREACH(lf, &loaded_files, loaded) {
 1489                 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
 1490                     &stop, NULL);
 1491                 /*
 1492                  * First, look to see if we would successfully link with this
 1493                  * stuff.
 1494                  */
 1495                 resolves = 1;   /* unless we know otherwise */
 1496                 if (!error) {
 1497                         for (mdp = start; mdp < stop; mdp++) {
 1498                                 mp = *mdp;
 1499                                 if (mp->md_type != MDT_DEPEND)
 1500                                         continue;
 1501                                 modname = mp->md_cval;
 1502                                 verinfo = mp->md_data;
 1503                                 for (nmdp = start; nmdp < stop; nmdp++) {
 1504                                         nmp = *nmdp;
 1505                                         if (nmp->md_type != MDT_VERSION)
 1506                                                 continue;
 1507                                         nmodname = nmp->md_cval;
 1508                                         if (strcmp(modname, nmodname) == 0)
 1509                                                 break;
 1510                                 }
 1511                                 if (nmdp < stop)   /* it's a self reference */
 1512                                         continue;
 1513 
 1514                                 /*
 1515                                  * ok, the module isn't here yet, we
 1516                                  * are not finished
 1517                                  */
 1518                                 if (modlist_lookup2(modname, verinfo) == NULL)
 1519                                         resolves = 0;
 1520                         }
 1521                 }
 1522                 /*
 1523                  * OK, if we found our modules, we can link.  So, "provide"
 1524                  * the modules inside and add it to the end of the link order
 1525                  * list.
 1526                  */
 1527                 if (resolves) {
 1528                         if (!error) {
 1529                                 for (mdp = start; mdp < stop; mdp++) {
 1530                                         mp = *mdp;
 1531                                         if (mp->md_type != MDT_VERSION)
 1532                                                 continue;
 1533                                         modname = mp->md_cval;
 1534                                         nver = ((struct mod_version *)
 1535                                             mp->md_data)->mv_version;
 1536                                         if (modlist_lookup(modname,
 1537                                             nver) != NULL) {
 1538                                                 printf("module %s already"
 1539                                                     " present!\n", modname);
 1540                                                 TAILQ_REMOVE(&loaded_files,
 1541                                                     lf, loaded);
 1542                                                 linker_file_unload(lf,
 1543                                                     LINKER_UNLOAD_FORCE);
 1544                                                 /* we changed tailq next ptr */
 1545                                                 goto restart;
 1546                                         }
 1547                                         modlist_newmodule(modname, nver, lf);
 1548                                 }
 1549                         }
 1550                         TAILQ_REMOVE(&loaded_files, lf, loaded);
 1551                         TAILQ_INSERT_TAIL(&depended_files, lf, loaded);
 1552                         /*
 1553                          * Since we provided modules, we need to restart the
 1554                          * sort so that the previous files that depend on us
 1555                          * have a chance. Also, we've busted the tailq next
 1556                          * pointer with the REMOVE.
 1557                          */
 1558                         goto restart;
 1559                 }
 1560         }
 1561 
 1562         /*
 1563          * At this point, we check to see what could not be resolved..
 1564          */
 1565         while ((lf = TAILQ_FIRST(&loaded_files)) != NULL) {
 1566                 TAILQ_REMOVE(&loaded_files, lf, loaded);
 1567                 printf("KLD file %s is missing dependencies\n", lf->filename);
 1568                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 1569         }
 1570 
 1571         /*
 1572          * We made it. Finish off the linking in the order we determined.
 1573          */
 1574         TAILQ_FOREACH_SAFE(lf, &depended_files, loaded, nlf) {
 1575                 if (linker_kernel_file) {
 1576                         linker_kernel_file->refs++;
 1577                         error = linker_file_add_dependency(lf,
 1578                             linker_kernel_file);
 1579                         if (error)
 1580                                 panic("cannot add dependency");
 1581                 }
 1582                 lf->userrefs++; /* so we can (try to) kldunload it */
 1583                 error = linker_file_lookup_set(lf, MDT_SETNAME, &start,
 1584                     &stop, NULL);
 1585                 if (!error) {
 1586                         for (mdp = start; mdp < stop; mdp++) {
 1587                                 mp = *mdp;
 1588                                 if (mp->md_type != MDT_DEPEND)
 1589                                         continue;
 1590                                 modname = mp->md_cval;
 1591                                 verinfo = mp->md_data;
 1592                                 mod = modlist_lookup2(modname, verinfo);
 1593                                 if (mod == NULL) {
 1594                                         printf("KLD file %s - cannot find "
 1595                                             "dependency \"%s\"\n",
 1596                                             lf->filename, modname);
 1597                                         goto fail;
 1598                                 }
 1599                                 /* Don't count self-dependencies */
 1600                                 if (lf == mod->container)
 1601                                         continue;
 1602                                 mod->container->refs++;
 1603                                 error = linker_file_add_dependency(lf,
 1604                                     mod->container);
 1605                                 if (error)
 1606                                         panic("cannot add dependency");
 1607                         }
 1608                 }
 1609                 /*
 1610                  * Now do relocation etc using the symbol search paths
 1611                  * established by the dependencies
 1612                  */
 1613                 error = LINKER_LINK_PRELOAD_FINISH(lf);
 1614                 if (error) {
 1615                         printf("KLD file %s - could not finalize loading\n",
 1616                             lf->filename);
 1617                         goto fail;
 1618                 }
 1619                 linker_file_register_modules(lf);
 1620                 if (linker_file_lookup_set(lf, "sysinit_set", &si_start,
 1621                     &si_stop, NULL) == 0)
 1622                         sysinit_add(si_start, si_stop);
 1623                 linker_file_register_sysctls(lf);
 1624                 lf->flags |= LINKER_FILE_LINKED;
 1625                 continue;
 1626 fail:
 1627                 TAILQ_REMOVE(&depended_files, lf, loaded);
 1628                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
 1629         }
 1630         sx_xunlock(&kld_sx);
 1631         /* woohoo! we made it! */
 1632 }
 1633 
 1634 SYSINIT(preload, SI_SUB_KLD, SI_ORDER_MIDDLE, linker_preload, 0);
 1635 
 1636 /*
 1637  * Search for a not-loaded module by name.
 1638  *
 1639  * Modules may be found in the following locations:
 1640  *
 1641  * - preloaded (result is just the module name) - on disk (result is full path
 1642  * to module)
 1643  *
 1644  * If the module name is qualified in any way (contains path, etc.) the we
 1645  * simply return a copy of it.
 1646  *
 1647  * The search path can be manipulated via sysctl.  Note that we use the ';'
 1648  * character as a separator to be consistent with the bootloader.
 1649  */
 1650 
 1651 static char linker_hintfile[] = "linker.hints";
 1652 static char linker_path[MAXPATHLEN] = "/boot/kernel;/boot/modules";
 1653 
 1654 SYSCTL_STRING(_kern, OID_AUTO, module_path, CTLFLAG_RW, linker_path,
 1655     sizeof(linker_path), "module load search path");
 1656 
 1657 TUNABLE_STR("module_path", linker_path, sizeof(linker_path));
 1658 
 1659 static char *linker_ext_list[] = {
 1660         "",
 1661         ".ko",
 1662         NULL
 1663 };
 1664 
 1665 /*
 1666  * Check if file actually exists either with or without extension listed in
 1667  * the linker_ext_list. (probably should be generic for the rest of the
 1668  * kernel)
 1669  */
 1670 static char *
 1671 linker_lookup_file(const char *path, int pathlen, const char *name,
 1672     int namelen, struct vattr *vap)
 1673 {
 1674         struct nameidata nd;
 1675         struct thread *td = curthread;  /* XXX */
 1676         char *result, **cpp, *sep;
 1677         int error, len, extlen, reclen, flags, vfslocked;
 1678         enum vtype type;
 1679 
 1680         extlen = 0;
 1681         for (cpp = linker_ext_list; *cpp; cpp++) {
 1682                 len = strlen(*cpp);
 1683                 if (len > extlen)
 1684                         extlen = len;
 1685         }
 1686         extlen++;               /* trailing '\0' */
 1687         sep = (path[pathlen - 1] != '/') ? "/" : "";
 1688 
 1689         reclen = pathlen + strlen(sep) + namelen + extlen + 1;
 1690         result = malloc(reclen, M_LINKER, M_WAITOK);
 1691         for (cpp = linker_ext_list; *cpp; cpp++) {
 1692                 snprintf(result, reclen, "%.*s%s%.*s%s", pathlen, path, sep,
 1693                     namelen, name, *cpp);
 1694                 /*
 1695                  * Attempt to open the file, and return the path if
 1696                  * we succeed and it's a regular file.
 1697                  */
 1698                 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, result, td);
 1699                 flags = FREAD;
 1700                 error = vn_open(&nd, &flags, 0, NULL);
 1701                 if (error == 0) {
 1702                         vfslocked = NDHASGIANT(&nd);
 1703                         NDFREE(&nd, NDF_ONLY_PNBUF);
 1704                         type = nd.ni_vp->v_type;
 1705                         if (vap)
 1706                                 VOP_GETATTR(nd.ni_vp, vap, td->td_ucred);
 1707                         VOP_UNLOCK(nd.ni_vp, 0);
 1708                         vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
 1709                         VFS_UNLOCK_GIANT(vfslocked);
 1710                         if (type == VREG)
 1711                                 return (result);
 1712                 }
 1713         }
 1714         free(result, M_LINKER);
 1715         return (NULL);
 1716 }
 1717 
 1718 #define INT_ALIGN(base, ptr)    ptr =                                   \
 1719         (base) + (((ptr) - (base) + sizeof(int) - 1) & ~(sizeof(int) - 1))
 1720 
 1721 /*
 1722  * Lookup KLD which contains requested module in the "linker.hints" file. If
 1723  * version specification is available, then try to find the best KLD.
 1724  * Otherwise just find the latest one.
 1725  */
 1726 static char *
 1727 linker_hints_lookup(const char *path, int pathlen, const char *modname,
 1728     int modnamelen, struct mod_depend *verinfo)
 1729 {
 1730         struct thread *td = curthread;  /* XXX */
 1731         struct ucred *cred = td ? td->td_ucred : NULL;
 1732         struct nameidata nd;
 1733         struct vattr vattr, mattr;
 1734         u_char *hints = NULL;
 1735         u_char *cp, *recptr, *bufend, *result, *best, *pathbuf, *sep;
 1736         int error, ival, bestver, *intp, found, flags, clen, blen;
 1737         ssize_t reclen;
 1738         int vfslocked = 0;
 1739 
 1740         result = NULL;
 1741         bestver = found = 0;
 1742 
 1743         sep = (path[pathlen - 1] != '/') ? "/" : "";
 1744         reclen = imax(modnamelen, strlen(linker_hintfile)) + pathlen +
 1745             strlen(sep) + 1;
 1746         pathbuf = malloc(reclen, M_LINKER, M_WAITOK);
 1747         snprintf(pathbuf, reclen, "%.*s%s%s", pathlen, path, sep,
 1748             linker_hintfile);
 1749 
 1750         NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, pathbuf, td);
 1751         flags = FREAD;
 1752         error = vn_open(&nd, &flags, 0, NULL);
 1753         if (error)
 1754                 goto bad;
 1755         vfslocked = NDHASGIANT(&nd);
 1756         NDFREE(&nd, NDF_ONLY_PNBUF);
 1757         if (nd.ni_vp->v_type != VREG)
 1758                 goto bad;
 1759         best = cp = NULL;
 1760         error = VOP_GETATTR(nd.ni_vp, &vattr, cred);
 1761         if (error)
 1762                 goto bad;
 1763         /*
 1764          * XXX: we need to limit this number to some reasonable value
 1765          */
 1766         if (vattr.va_size > 100 * 1024) {
 1767                 printf("hints file too large %ld\n", (long)vattr.va_size);
 1768                 goto bad;
 1769         }
 1770         hints = malloc(vattr.va_size, M_TEMP, M_WAITOK);
 1771         if (hints == NULL)
 1772                 goto bad;
 1773         error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)hints, vattr.va_size, 0,
 1774             UIO_SYSSPACE, IO_NODELOCKED, cred, NOCRED, &reclen, td);
 1775         if (error)
 1776                 goto bad;
 1777         VOP_UNLOCK(nd.ni_vp, 0);
 1778         vn_close(nd.ni_vp, FREAD, cred, td);
 1779         VFS_UNLOCK_GIANT(vfslocked);
 1780         nd.ni_vp = NULL;
 1781         if (reclen != 0) {
 1782                 printf("can't read %zd\n", reclen);
 1783                 goto bad;
 1784         }
 1785         intp = (int *)hints;
 1786         ival = *intp++;
 1787         if (ival != LINKER_HINTS_VERSION) {
 1788                 printf("hints file version mismatch %d\n", ival);
 1789                 goto bad;
 1790         }
 1791         bufend = hints + vattr.va_size;
 1792         recptr = (u_char *)intp;
 1793         clen = blen = 0;
 1794         while (recptr < bufend && !found) {
 1795                 intp = (int *)recptr;
 1796                 reclen = *intp++;
 1797                 ival = *intp++;
 1798                 cp = (char *)intp;
 1799                 switch (ival) {
 1800                 case MDT_VERSION:
 1801                         clen = *cp++;
 1802                         if (clen != modnamelen || bcmp(cp, modname, clen) != 0)
 1803                                 break;
 1804                         cp += clen;
 1805                         INT_ALIGN(hints, cp);
 1806                         ival = *(int *)cp;
 1807                         cp += sizeof(int);
 1808                         clen = *cp++;
 1809                         if (verinfo == NULL ||
 1810                             ival == verinfo->md_ver_preferred) {
 1811                                 found = 1;
 1812                                 break;
 1813                         }
 1814                         if (ival >= verinfo->md_ver_minimum &&
 1815                             ival <= verinfo->md_ver_maximum &&
 1816                             ival > bestver) {
 1817                                 bestver = ival;
 1818                                 best = cp;
 1819                                 blen = clen;
 1820                         }
 1821                         break;
 1822                 default:
 1823                         break;
 1824                 }
 1825                 recptr += reclen + sizeof(int);
 1826         }
 1827         /*
 1828          * Finally check if KLD is in the place
 1829          */
 1830         if (found)
 1831                 result = linker_lookup_file(path, pathlen, cp, clen, &mattr);
 1832         else if (best)
 1833                 result = linker_lookup_file(path, pathlen, best, blen, &mattr);
 1834 
 1835         /*
 1836          * KLD is newer than hints file. What we should do now?
 1837          */
 1838         if (result && timespeccmp(&mattr.va_mtime, &vattr.va_mtime, >))
 1839                 printf("warning: KLD '%s' is newer than the linker.hints"
 1840                     " file\n", result);
 1841 bad:
 1842         free(pathbuf, M_LINKER);
 1843         if (hints)
 1844                 free(hints, M_TEMP);
 1845         if (nd.ni_vp != NULL) {
 1846                 VOP_UNLOCK(nd.ni_vp, 0);
 1847                 vn_close(nd.ni_vp, FREAD, cred, td);
 1848                 VFS_UNLOCK_GIANT(vfslocked);
 1849         }
 1850         /*
 1851          * If nothing found or hints is absent - fallback to the old
 1852          * way by using "kldname[.ko]" as module name.
 1853          */
 1854         if (!found && !bestver && result == NULL)
 1855                 result = linker_lookup_file(path, pathlen, modname,
 1856                     modnamelen, NULL);
 1857         return (result);
 1858 }
 1859 
 1860 /*
 1861  * Lookup KLD which contains requested module in the all directories.
 1862  */
 1863 static char *
 1864 linker_search_module(const char *modname, int modnamelen,
 1865     struct mod_depend *verinfo)
 1866 {
 1867         char *cp, *ep, *result;
 1868 
 1869         /*
 1870          * traverse the linker path
 1871          */
 1872         for (cp = linker_path; *cp; cp = ep + 1) {
 1873                 /* find the end of this component */
 1874                 for (ep = cp; (*ep != 0) && (*ep != ';'); ep++);
 1875                 result = linker_hints_lookup(cp, ep - cp, modname,
 1876                     modnamelen, verinfo);
 1877                 if (result != NULL)
 1878                         return (result);
 1879                 if (*ep == 0)
 1880                         break;
 1881         }
 1882         return (NULL);
 1883 }
 1884 
 1885 /*
 1886  * Search for module in all directories listed in the linker_path.
 1887  */
 1888 static char *
 1889 linker_search_kld(const char *name)
 1890 {
 1891         char *cp, *ep, *result;
 1892         int len;
 1893 
 1894         /* qualified at all? */
 1895         if (index(name, '/'))
 1896                 return (linker_strdup(name));
 1897 
 1898         /* traverse the linker path */
 1899         len = strlen(name);
 1900         for (ep = linker_path; *ep; ep++) {
 1901                 cp = ep;
 1902                 /* find the end of this component */
 1903                 for (; *ep != 0 && *ep != ';'; ep++);
 1904                 result = linker_lookup_file(cp, ep - cp, name, len, NULL);
 1905                 if (result != NULL)
 1906                         return (result);
 1907         }
 1908         return (NULL);
 1909 }
 1910 
 1911 static const char *
 1912 linker_basename(const char *path)
 1913 {
 1914         const char *filename;
 1915 
 1916         filename = rindex(path, '/');
 1917         if (filename == NULL)
 1918                 return path;
 1919         if (filename[1])
 1920                 filename++;
 1921         return (filename);
 1922 }
 1923 
 1924 #ifdef HWPMC_HOOKS
 1925 /*
 1926  * Inform hwpmc about the set of kernel modules currently loaded.
 1927  */
 1928 void *
 1929 linker_hwpmc_list_objects(void)
 1930 {
 1931         linker_file_t lf;
 1932         struct pmckern_map_in *kobase;
 1933         int i, nmappings;
 1934 
 1935         nmappings = 0;
 1936         sx_slock(&kld_sx);
 1937         TAILQ_FOREACH(lf, &linker_files, link)
 1938                 nmappings++;
 1939 
 1940         /* Allocate nmappings + 1 entries. */
 1941         kobase = malloc((nmappings + 1) * sizeof(struct pmckern_map_in),
 1942             M_LINKER, M_WAITOK | M_ZERO);
 1943         i = 0;
 1944         TAILQ_FOREACH(lf, &linker_files, link) {
 1945 
 1946                 /* Save the info for this linker file. */
 1947                 kobase[i].pm_file = lf->filename;
 1948                 kobase[i].pm_address = (uintptr_t)lf->address;
 1949                 i++;
 1950         }
 1951         sx_sunlock(&kld_sx);
 1952 
 1953         KASSERT(i > 0, ("linker_hpwmc_list_objects: no kernel objects?"));
 1954 
 1955         /* The last entry of the malloced area comprises of all zeros. */
 1956         KASSERT(kobase[i].pm_file == NULL,
 1957             ("linker_hwpmc_list_objects: last object not NULL"));
 1958 
 1959         return ((void *)kobase);
 1960 }
 1961 #endif
 1962 
 1963 /*
 1964  * Find a file which contains given module and load it, if "parent" is not
 1965  * NULL, register a reference to it.
 1966  */
 1967 static int
 1968 linker_load_module(const char *kldname, const char *modname,
 1969     struct linker_file *parent, struct mod_depend *verinfo,
 1970     struct linker_file **lfpp)
 1971 {
 1972         linker_file_t lfdep;
 1973         const char *filename;
 1974         char *pathname;
 1975         int error;
 1976 
 1977         sx_assert(&kld_sx, SA_XLOCKED);
 1978         if (modname == NULL) {
 1979                 /*
 1980                  * We have to load KLD
 1981                  */
 1982                 KASSERT(verinfo == NULL, ("linker_load_module: verinfo"
 1983                     " is not NULL"));
 1984                 pathname = linker_search_kld(kldname);
 1985         } else {
 1986                 if (modlist_lookup2(modname, verinfo) != NULL)
 1987                         return (EEXIST);
 1988                 if (kldname != NULL)
 1989                         pathname = linker_strdup(kldname);
 1990                 else if (rootvnode == NULL)
 1991                         pathname = NULL;
 1992                 else
 1993                         /*
 1994                          * Need to find a KLD with required module
 1995                          */
 1996                         pathname = linker_search_module(modname,
 1997                             strlen(modname), verinfo);
 1998         }
 1999         if (pathname == NULL)
 2000                 return (ENOENT);
 2001 
 2002         /*
 2003          * Can't load more than one file with the same basename XXX:
 2004          * Actually it should be possible to have multiple KLDs with
 2005          * the same basename but different path because they can
 2006          * provide different versions of the same modules.
 2007          */
 2008         filename = linker_basename(pathname);
 2009         if (linker_find_file_by_name(filename))
 2010                 error = EEXIST;
 2011         else do {
 2012                 error = linker_load_file(pathname, &lfdep);
 2013                 if (error)
 2014                         break;
 2015                 if (modname && verinfo &&
 2016                     modlist_lookup2(modname, verinfo) == NULL) {
 2017                         linker_file_unload(lfdep, LINKER_UNLOAD_FORCE);
 2018                         error = ENOENT;
 2019                         break;
 2020                 }
 2021                 if (parent) {
 2022                         error = linker_file_add_dependency(parent, lfdep);
 2023                         if (error)
 2024                                 break;
 2025                 }
 2026                 if (lfpp)
 2027                         *lfpp = lfdep;
 2028         } while (0);
 2029         free(pathname, M_LINKER);
 2030         return (error);
 2031 }
 2032 
 2033 /*
 2034  * This routine is responsible for finding dependencies of userland initiated
 2035  * kldload(2)'s of files.
 2036  */
 2037 int
 2038 linker_load_dependencies(linker_file_t lf)
 2039 {
 2040         linker_file_t lfdep;
 2041         struct mod_metadata **start, **stop, **mdp, **nmdp;
 2042         struct mod_metadata *mp, *nmp;
 2043         struct mod_depend *verinfo;
 2044         modlist_t mod;
 2045         const char *modname, *nmodname;
 2046         int ver, error = 0, count;
 2047 
 2048         /*
 2049          * All files are dependant on /kernel.
 2050          */
 2051         sx_assert(&kld_sx, SA_XLOCKED);
 2052         if (linker_kernel_file) {
 2053                 linker_kernel_file->refs++;
 2054                 error = linker_file_add_dependency(lf, linker_kernel_file);
 2055                 if (error)
 2056                         return (error);
 2057         }
 2058         if (linker_file_lookup_set(lf, MDT_SETNAME, &start, &stop,
 2059             &count) != 0)
 2060                 return (0);
 2061         for (mdp = start; mdp < stop; mdp++) {
 2062                 mp = *mdp;
 2063                 if (mp->md_type != MDT_VERSION)
 2064                         continue;
 2065                 modname = mp->md_cval;
 2066                 ver = ((struct mod_version *)mp->md_data)->mv_version;
 2067                 mod = modlist_lookup(modname, ver);
 2068                 if (mod != NULL) {
 2069                         printf("interface %s.%d already present in the KLD"
 2070                             " '%s'!\n", modname, ver,
 2071                             mod->container->filename);
 2072                         return (EEXIST);
 2073                 }
 2074         }
 2075 
 2076         for (mdp = start; mdp < stop; mdp++) {
 2077                 mp = *mdp;
 2078                 if (mp->md_type != MDT_DEPEND)
 2079                         continue;
 2080                 modname = mp->md_cval;
 2081                 verinfo = mp->md_data;
 2082                 nmodname = NULL;
 2083                 for (nmdp = start; nmdp < stop; nmdp++) {
 2084                         nmp = *nmdp;
 2085                         if (nmp->md_type != MDT_VERSION)
 2086                                 continue;
 2087                         nmodname = nmp->md_cval;
 2088                         if (strcmp(modname, nmodname) == 0)
 2089                                 break;
 2090                 }
 2091                 if (nmdp < stop)/* early exit, it's a self reference */
 2092                         continue;
 2093                 mod = modlist_lookup2(modname, verinfo);
 2094                 if (mod) {      /* woohoo, it's loaded already */
 2095                         lfdep = mod->container;
 2096                         lfdep->refs++;
 2097                         error = linker_file_add_dependency(lf, lfdep);
 2098                         if (error)
 2099                                 break;
 2100                         continue;
 2101                 }
 2102                 error = linker_load_module(NULL, modname, lf, verinfo, NULL);
 2103                 if (error) {
 2104                         printf("KLD %s: depends on %s - not available or"
 2105                             " version mismatch\n", lf->filename, modname);
 2106                         break;
 2107                 }
 2108         }
 2109 
 2110         if (error)
 2111                 return (error);
 2112         linker_addmodules(lf, start, stop, 0);
 2113         return (error);
 2114 }
 2115 
 2116 static int
 2117 sysctl_kern_function_list_iterate(const char *name, void *opaque)
 2118 {
 2119         struct sysctl_req *req;
 2120 
 2121         req = opaque;
 2122         return (SYSCTL_OUT(req, name, strlen(name) + 1));
 2123 }
 2124 
 2125 /*
 2126  * Export a nul-separated, double-nul-terminated list of all function names
 2127  * in the kernel.
 2128  */
 2129 static int
 2130 sysctl_kern_function_list(SYSCTL_HANDLER_ARGS)
 2131 {
 2132         linker_file_t lf;
 2133         int error;
 2134 
 2135 #ifdef MAC
 2136         error = mac_kld_check_stat(req->td->td_ucred);
 2137         if (error)
 2138                 return (error);
 2139 #endif
 2140         error = sysctl_wire_old_buffer(req, 0);
 2141         if (error != 0)
 2142                 return (error);
 2143         sx_xlock(&kld_sx);
 2144         TAILQ_FOREACH(lf, &linker_files, link) {
 2145                 error = LINKER_EACH_FUNCTION_NAME(lf,
 2146                     sysctl_kern_function_list_iterate, req);
 2147                 if (error) {
 2148                         sx_xunlock(&kld_sx);
 2149                         return (error);
 2150                 }
 2151         }
 2152         sx_xunlock(&kld_sx);
 2153         return (SYSCTL_OUT(req, "", 1));
 2154 }
 2155 
 2156 SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLTYPE_OPAQUE | CTLFLAG_RD,
 2157     NULL, 0, sysctl_kern_function_list, "", "kernel function list");

Cache object: 238bd944792734dd257e3281eee0375b


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.