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/link_elf_obj.c

Version: -  FREEBSD  -  FREEBSD-13-STABLE  -  FREEBSD-13-0  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  l41  -  OPENBSD  -  linux-2.6  -  MK84  -  PLAN9  -  xnu-8792 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * Copyright (c) 1998-2000 Doug Rabson
    3  * Copyright (c) 2004 Peter Wemm
    4  * All rights reserved.
    5  *
    6  * Redistribution and use in source and binary forms, with or without
    7  * modification, are permitted provided that the following conditions
    8  * are met:
    9  * 1. Redistributions of source code must retain the above copyright
   10  *    notice, this list of conditions and the following disclaimer.
   11  * 2. Redistributions in binary form must reproduce the above copyright
   12  *    notice, this list of conditions and the following disclaimer in the
   13  *    documentation and/or other materials provided with the distribution.
   14  *
   15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   25  * SUCH DAMAGE.
   26  */
   27 
   28 #include <sys/cdefs.h>
   29 __FBSDID("$FreeBSD$");
   30 
   31 #include "opt_ddb.h"
   32 #include "opt_mac.h"
   33 
   34 #include <sys/param.h>
   35 #include <sys/systm.h>
   36 #include <sys/kernel.h>
   37 #include <sys/lock.h>
   38 #include <sys/malloc.h>
   39 #include <sys/mutex.h>
   40 #include <sys/mount.h>
   41 #include <sys/proc.h>
   42 #include <sys/namei.h>
   43 #include <sys/fcntl.h>
   44 #include <sys/vnode.h>
   45 #include <sys/linker.h>
   46 
   47 #include <machine/elf.h>
   48 
   49 #include <security/mac/mac_framework.h>
   50 
   51 #include <vm/vm.h>
   52 #include <vm/vm_param.h>
   53 #include <vm/vm_object.h>
   54 #include <vm/vm_kern.h>
   55 #include <vm/vm_extern.h>
   56 #include <vm/pmap.h>
   57 #include <vm/vm_map.h>
   58 
   59 #include <sys/link_elf.h>
   60 
   61 #ifdef DDB_CTF
   62 #include <net/zlib.h>
   63 #endif
   64 
   65 #include "linker_if.h"
   66 
   67 typedef struct {
   68         void            *addr;
   69         Elf_Off         size;
   70         int             flags;
   71         int             sec;    /* Original section */
   72         char            *name;
   73 } Elf_progent;
   74 
   75 typedef struct {
   76         Elf_Rel         *rel;
   77         int             nrel;
   78         int             sec;
   79 } Elf_relent;
   80 
   81 typedef struct {
   82         Elf_Rela        *rela;
   83         int             nrela;
   84         int             sec;
   85 } Elf_relaent;
   86 
   87 
   88 typedef struct elf_file {
   89         struct linker_file lf;          /* Common fields */
   90 
   91         int             preloaded;
   92         caddr_t         address;        /* Relocation address */
   93         vm_object_t     object;         /* VM object to hold file pages */
   94         Elf_Shdr        *e_shdr;
   95 
   96         Elf_progent     *progtab;
   97         int             nprogtab;
   98 
   99         Elf_relaent     *relatab;
  100         int             nrelatab;
  101 
  102         Elf_relent      *reltab;
  103         int             nreltab;
  104 
  105         Elf_Sym         *ddbsymtab;     /* The symbol table we are using */
  106         long            ddbsymcnt;      /* Number of symbols */
  107         caddr_t         ddbstrtab;      /* String table */
  108         long            ddbstrcnt;      /* number of bytes in string table */
  109 
  110         caddr_t         shstrtab;       /* Section name string table */
  111         long            shstrcnt;       /* number of bytes in string table */
  112 
  113         caddr_t         ctftab;         /* CTF table */
  114         long            ctfcnt;         /* number of bytes in CTF table */
  115         caddr_t         ctfoff;         /* CTF offset table */
  116         caddr_t         typoff;         /* Type offset table */
  117         long            typlen;         /* Number of type entries. */
  118 
  119 } *elf_file_t;
  120 
  121 #include <kern/kern_ctf.c>
  122 
  123 static int      link_elf_link_preload(linker_class_t cls,
  124                     const char *, linker_file_t *);
  125 static int      link_elf_link_preload_finish(linker_file_t);
  126 static int      link_elf_load_file(linker_class_t, const char *, linker_file_t *);
  127 static int      link_elf_lookup_symbol(linker_file_t, const char *,
  128                     c_linker_sym_t *);
  129 static int      link_elf_symbol_values(linker_file_t, c_linker_sym_t,
  130                     linker_symval_t *);
  131 static int      link_elf_search_symbol(linker_file_t, caddr_t value,
  132                     c_linker_sym_t *sym, long *diffp);
  133 
  134 static void     link_elf_unload_file(linker_file_t);
  135 static int      link_elf_lookup_set(linker_file_t, const char *,
  136                     void ***, void ***, int *);
  137 static int      link_elf_each_function_name(linker_file_t,
  138                     int (*)(const char *, void *), void *);
  139 static int      link_elf_each_function_nameval(linker_file_t,
  140                                 linker_function_nameval_callback_t,
  141                                 void *);
  142 static void     link_elf_reloc_local(linker_file_t);
  143 
  144 static Elf_Addr elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps);
  145 
  146 static kobj_method_t link_elf_methods[] = {
  147         KOBJMETHOD(linker_lookup_symbol,        link_elf_lookup_symbol),
  148         KOBJMETHOD(linker_symbol_values,        link_elf_symbol_values),
  149         KOBJMETHOD(linker_search_symbol,        link_elf_search_symbol),
  150         KOBJMETHOD(linker_unload,               link_elf_unload_file),
  151         KOBJMETHOD(linker_load_file,            link_elf_load_file),
  152         KOBJMETHOD(linker_link_preload,         link_elf_link_preload),
  153         KOBJMETHOD(linker_link_preload_finish,  link_elf_link_preload_finish),
  154         KOBJMETHOD(linker_lookup_set,           link_elf_lookup_set),
  155         KOBJMETHOD(linker_each_function_name,   link_elf_each_function_name),
  156         KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
  157         KOBJMETHOD(linker_ctf_get,              link_elf_ctf_get),
  158         { 0, 0 }
  159 };
  160 
  161 static struct linker_class link_elf_class = {
  162 #if ELF_TARG_CLASS == ELFCLASS32
  163         "elf32_obj",
  164 #else
  165         "elf64_obj",
  166 #endif
  167         link_elf_methods, sizeof(struct elf_file)
  168 };
  169 
  170 static int      relocate_file(elf_file_t ef);
  171 
  172 static void
  173 link_elf_error(const char *filename, const char *s)
  174 {
  175         if (filename == NULL)
  176                 printf("kldload: %s\n", s);
  177         else
  178                 printf("kldload: %s: %s\n", filename, s);
  179 }
  180 
  181 static void
  182 link_elf_init(void *arg)
  183 {
  184 
  185         linker_add_class(&link_elf_class);
  186 }
  187 
  188 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, 0);
  189 
  190 static int
  191 link_elf_link_preload(linker_class_t cls, const char *filename,
  192     linker_file_t *result)
  193 {
  194         Elf_Ehdr *hdr;
  195         Elf_Shdr *shdr;
  196         Elf_Sym *es;
  197         void *modptr, *baseptr, *sizeptr;
  198         char *type;
  199         elf_file_t ef;
  200         linker_file_t lf;
  201         Elf_Addr off;
  202         int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex;
  203 
  204         /* Look to see if we have the file preloaded */
  205         modptr = preload_search_by_name(filename);
  206         if (modptr == NULL)
  207                 return ENOENT;
  208 
  209         type = (char *)preload_search_info(modptr, MODINFO_TYPE);
  210         baseptr = preload_search_info(modptr, MODINFO_ADDR);
  211         sizeptr = preload_search_info(modptr, MODINFO_SIZE);
  212         hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA |
  213             MODINFOMD_ELFHDR);
  214         shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA |
  215             MODINFOMD_SHDR);
  216         if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE)
  217             " obj module") != 0 &&
  218             strcmp(type, "elf obj module") != 0)) {
  219                 return (EFTYPE);
  220         }
  221         if (baseptr == NULL || sizeptr == NULL || hdr == NULL ||
  222             shdr == NULL)
  223                 return (EINVAL);
  224 
  225         lf = linker_make_file(filename, &link_elf_class);
  226         if (lf == NULL)
  227                 return (ENOMEM);
  228 
  229         ef = (elf_file_t)lf;
  230         ef->preloaded = 1;
  231         ef->address = *(caddr_t *)baseptr;
  232         lf->address = *(caddr_t *)baseptr;
  233         lf->size = *(size_t *)sizeptr;
  234 
  235         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
  236             hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
  237             hdr->e_ident[EI_VERSION] != EV_CURRENT ||
  238             hdr->e_version != EV_CURRENT ||
  239             hdr->e_type != ET_REL ||
  240             hdr->e_machine != ELF_TARG_MACH) {
  241                 error = EFTYPE;
  242                 goto out;
  243         }
  244         ef->e_shdr = shdr;
  245 
  246         /* Scan the section header for information and table sizing. */
  247         symtabindex = -1;
  248         symstrindex = -1;
  249         for (i = 0; i < hdr->e_shnum; i++) {
  250                 switch (shdr[i].sh_type) {
  251                 case SHT_PROGBITS:
  252                 case SHT_NOBITS:
  253                         ef->nprogtab++;
  254                         break;
  255                 case SHT_SYMTAB:
  256                         symtabindex = i;
  257                         symstrindex = shdr[i].sh_link;
  258                         break;
  259                 case SHT_REL:
  260                         ef->nreltab++;
  261                         break;
  262                 case SHT_RELA:
  263                         ef->nrelatab++;
  264                         break;
  265                 }
  266         }
  267 
  268         shstrindex = hdr->e_shstrndx;
  269         if (ef->nprogtab == 0 || symstrindex < 0 ||
  270             symstrindex >= hdr->e_shnum ||
  271             shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
  272             shstrindex >= hdr->e_shnum ||
  273             shdr[shstrindex].sh_type != SHT_STRTAB) {
  274                 printf("%s: bad/missing section headers\n", filename);
  275                 error = ENOEXEC;
  276                 goto out;
  277         }
  278 
  279         /* Allocate space for tracking the load chunks */
  280         if (ef->nprogtab != 0)
  281                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
  282                     M_LINKER, M_WAITOK | M_ZERO);
  283         if (ef->nreltab != 0)
  284                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
  285                     M_LINKER, M_WAITOK | M_ZERO);
  286         if (ef->nrelatab != 0)
  287                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
  288                     M_LINKER, M_WAITOK | M_ZERO);
  289         if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
  290             (ef->nreltab != 0 && ef->reltab == NULL) ||
  291             (ef->nrelatab != 0 && ef->relatab == NULL)) {
  292                 error = ENOMEM;
  293                 goto out;
  294         }
  295 
  296         /* XXX, relocate the sh_addr fields saved by the loader. */
  297         off = 0;
  298         for (i = 0; i < hdr->e_shnum; i++) {
  299                 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
  300                         off = shdr[i].sh_addr;
  301         }
  302         for (i = 0; i < hdr->e_shnum; i++) {
  303                 if (shdr[i].sh_addr != 0)
  304                         shdr[i].sh_addr = shdr[i].sh_addr - off +
  305                             (Elf_Addr)ef->address;
  306         }
  307 
  308         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
  309         ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
  310         ef->ddbstrcnt = shdr[symstrindex].sh_size;
  311         ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
  312         ef->shstrcnt = shdr[shstrindex].sh_size;
  313         ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
  314 
  315         /* Now fill out progtab and the relocation tables. */
  316         pb = 0;
  317         rl = 0;
  318         ra = 0;
  319         for (i = 0; i < hdr->e_shnum; i++) {
  320                 switch (shdr[i].sh_type) {
  321                 case SHT_PROGBITS:
  322                 case SHT_NOBITS:
  323                         ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
  324                         if (shdr[i].sh_type == SHT_PROGBITS)
  325                                 ef->progtab[pb].name = "<<PROGBITS>>";
  326                         else
  327                                 ef->progtab[pb].name = "<<NOBITS>>";
  328                         ef->progtab[pb].size = shdr[i].sh_size;
  329                         ef->progtab[pb].sec = i;
  330                         if (ef->shstrtab && shdr[i].sh_name != 0)
  331                                 ef->progtab[pb].name =
  332                                     ef->shstrtab + shdr[i].sh_name;
  333 
  334                         /* Update all symbol values with the offset. */
  335                         for (j = 0; j < ef->ddbsymcnt; j++) {
  336                                 es = &ef->ddbsymtab[j];
  337                                 if (es->st_shndx != i)
  338                                         continue;
  339                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
  340                         }
  341                         pb++;
  342                         break;
  343                 case SHT_REL:
  344                         ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
  345                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
  346                         ef->reltab[rl].sec = shdr[i].sh_info;
  347                         rl++;
  348                         break;
  349                 case SHT_RELA:
  350                         ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
  351                         ef->relatab[ra].nrela =
  352                             shdr[i].sh_size / sizeof(Elf_Rela);
  353                         ef->relatab[ra].sec = shdr[i].sh_info;
  354                         ra++;
  355                         break;
  356                 }
  357         }
  358         if (pb != ef->nprogtab)
  359                 panic("lost progbits");
  360         if (rl != ef->nreltab)
  361                 panic("lost reltab");
  362         if (ra != ef->nrelatab)
  363                 panic("lost relatab");
  364 
  365         /* Local intra-module relocations */
  366         link_elf_reloc_local(lf);
  367 
  368         *result = lf;
  369         return (0);
  370 
  371 out:
  372         /* preload not done this way */
  373         linker_file_unload(lf, LINKER_UNLOAD_FORCE);
  374         return (error);
  375 }
  376 
  377 static int
  378 link_elf_link_preload_finish(linker_file_t lf)
  379 {
  380         elf_file_t ef;
  381         int error;
  382 
  383         ef = (elf_file_t)lf;
  384         error = relocate_file(ef);
  385         if (error)
  386                 return error;
  387 
  388         /* Notify MD code that a module is being loaded. */
  389         error = elf_cpu_load_file(lf);
  390         if (error)
  391                 return (error);
  392 
  393         return (0);
  394 }
  395 
  396 static int
  397 link_elf_load_file(linker_class_t cls, const char *filename,
  398     linker_file_t *result)
  399 {
  400         struct nameidata nd;
  401         struct thread *td = curthread;  /* XXX */
  402         Elf_Ehdr *hdr;
  403         Elf_Shdr *shdr;
  404         Elf_Sym *es;
  405         int nbytes, i, j;
  406         vm_offset_t mapbase;
  407         size_t mapsize;
  408         int error = 0;
  409         int resid, flags;
  410         elf_file_t ef;
  411         linker_file_t lf;
  412         int symtabindex;
  413         int symstrindex;
  414         int shstrindex;
  415         int nsym;
  416         int pb, rl, ra;
  417         int alignmask;
  418         int vfslocked;
  419 
  420         shdr = NULL;
  421         lf = NULL;
  422         mapsize = 0;
  423         hdr = NULL;
  424 
  425         NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, filename, td);
  426         flags = FREAD;
  427         error = vn_open(&nd, &flags, 0, NULL);
  428         if (error)
  429                 return error;
  430         vfslocked = NDHASGIANT(&nd);
  431         NDFREE(&nd, NDF_ONLY_PNBUF);
  432         if (nd.ni_vp->v_type != VREG) {
  433                 error = ENOEXEC;
  434                 goto out;
  435         }
  436 #ifdef MAC
  437         error = mac_check_kld_load(td->td_ucred, nd.ni_vp);
  438         if (error) {
  439                 goto out;
  440         }
  441 #endif
  442 
  443         /* Read the elf header from the file. */
  444         hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
  445         if (hdr == NULL) {
  446                 error = ENOMEM;
  447                 goto out;
  448         }
  449         error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
  450             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
  451             &resid, td);
  452         if (error)
  453                 goto out;
  454         if (resid != 0){
  455                 error = ENOEXEC;
  456                 goto out;
  457         }
  458 
  459         if (!IS_ELF(*hdr)) {
  460                 error = ENOEXEC;
  461                 goto out;
  462         }
  463 
  464         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
  465             || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
  466                 link_elf_error(filename, "Unsupported file layout");
  467                 error = ENOEXEC;
  468                 goto out;
  469         }
  470         if (hdr->e_ident[EI_VERSION] != EV_CURRENT
  471             || hdr->e_version != EV_CURRENT) {
  472                 link_elf_error(filename, "Unsupported file version");
  473                 error = ENOEXEC;
  474                 goto out;
  475         }
  476         if (hdr->e_type != ET_REL) {
  477                 link_elf_error(filename, "Unsupported file type");
  478                 error = ENOEXEC;
  479                 goto out;
  480         }
  481         if (hdr->e_machine != ELF_TARG_MACH) {
  482                 link_elf_error(filename, "Unsupported machine");
  483                 error = ENOEXEC;
  484                 goto out;
  485         }
  486 
  487         lf = linker_make_file(filename, &link_elf_class);
  488         if (!lf) {
  489                 error = ENOMEM;
  490                 goto out;
  491         }
  492         ef = (elf_file_t) lf;
  493         ef->nprogtab = 0;
  494         ef->e_shdr = 0;
  495         ef->nreltab = 0;
  496         ef->nrelatab = 0;
  497 
  498         /* Allocate and read in the section header */
  499         nbytes = hdr->e_shnum * hdr->e_shentsize;
  500         if (nbytes == 0 || hdr->e_shoff == 0 ||
  501             hdr->e_shentsize != sizeof(Elf_Shdr)) {
  502                 error = ENOEXEC;
  503                 goto out;
  504         }
  505         shdr = malloc(nbytes, M_LINKER, M_WAITOK);
  506         if (shdr == NULL) {
  507                 error = ENOMEM;
  508                 goto out;
  509         }
  510         ef->e_shdr = shdr;
  511         error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
  512             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
  513         if (error)
  514                 goto out;
  515         if (resid) {
  516                 error = ENOEXEC;
  517                 goto out;
  518         }
  519 
  520         /* Scan the section header for information and table sizing. */
  521         nsym = 0;
  522         symtabindex = -1;
  523         symstrindex = -1;
  524         for (i = 0; i < hdr->e_shnum; i++) {
  525                 switch (shdr[i].sh_type) {
  526                 case SHT_PROGBITS:
  527                 case SHT_NOBITS:
  528                         ef->nprogtab++;
  529                         break;
  530                 case SHT_SYMTAB:
  531                         nsym++;
  532                         symtabindex = i;
  533                         symstrindex = shdr[i].sh_link;
  534                         break;
  535                 case SHT_REL:
  536                         ef->nreltab++;
  537                         break;
  538                 case SHT_RELA:
  539                         ef->nrelatab++;
  540                         break;
  541                 case SHT_STRTAB:
  542                         break;
  543                 }
  544         }
  545         if (ef->nprogtab == 0) {
  546                 link_elf_error(filename, "file has no contents");
  547                 error = ENOEXEC;
  548                 goto out;
  549         }
  550         if (nsym != 1) {
  551                 /* Only allow one symbol table for now */
  552                 link_elf_error(filename, "file has no valid symbol table");
  553                 error = ENOEXEC;
  554                 goto out;
  555         }
  556         if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
  557             shdr[symstrindex].sh_type != SHT_STRTAB) {
  558                 link_elf_error(filename, "file has invalid symbol strings");
  559                 error = ENOEXEC;
  560                 goto out;
  561         }
  562 
  563         /* Allocate space for tracking the load chunks */
  564         if (ef->nprogtab != 0)
  565                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
  566                     M_LINKER, M_WAITOK | M_ZERO);
  567         if (ef->nreltab != 0)
  568                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
  569                     M_LINKER, M_WAITOK | M_ZERO);
  570         if (ef->nrelatab != 0)
  571                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
  572                     M_LINKER, M_WAITOK | M_ZERO);
  573         if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
  574             (ef->nreltab != 0 && ef->reltab == NULL) ||
  575             (ef->nrelatab != 0 && ef->relatab == NULL)) {
  576                 error = ENOMEM;
  577                 goto out;
  578         }
  579 
  580         if (symtabindex == -1)
  581                 panic("lost symbol table index");
  582         /* Allocate space for and load the symbol table */
  583         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
  584         ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
  585         if (ef->ddbsymtab == NULL) {
  586                 error = ENOMEM;
  587                 goto out;
  588         }
  589         error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
  590             shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
  591             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
  592             &resid, td);
  593         if (error)
  594                 goto out;
  595         if (resid != 0){
  596                 error = EINVAL;
  597                 goto out;
  598         }
  599 
  600         if (symstrindex == -1)
  601                 panic("lost symbol string index");
  602         /* Allocate space for and load the symbol strings */
  603         ef->ddbstrcnt = shdr[symstrindex].sh_size;
  604         ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
  605         if (ef->ddbstrtab == NULL) {
  606                 error = ENOMEM;
  607                 goto out;
  608         }
  609         error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
  610             shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
  611             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
  612             &resid, td);
  613         if (error)
  614                 goto out;
  615         if (resid != 0){
  616                 error = EINVAL;
  617                 goto out;
  618         }
  619 
  620         /* Do we have a string table for the section names?  */
  621         shstrindex = -1;
  622         if (hdr->e_shstrndx != 0 &&
  623             shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
  624                 shstrindex = hdr->e_shstrndx;
  625                 ef->shstrcnt = shdr[shstrindex].sh_size;
  626                 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
  627                     M_WAITOK);
  628                 if (ef->shstrtab == NULL) {
  629                         error = ENOMEM;
  630                         goto out;
  631                 }
  632                 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
  633                     shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
  634                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
  635                     &resid, td);
  636                 if (error)
  637                         goto out;
  638                 if (resid != 0){
  639                         error = EINVAL;
  640                         goto out;
  641                 }
  642         }
  643 
  644         /* Size up code/data(progbits) and bss(nobits). */
  645         alignmask = 0;
  646         for (i = 0; i < hdr->e_shnum; i++) {
  647                 switch (shdr[i].sh_type) {
  648                 case SHT_PROGBITS:
  649                 case SHT_NOBITS:
  650                         alignmask = shdr[i].sh_addralign - 1;
  651                         mapsize += alignmask;
  652                         mapsize &= ~alignmask;
  653                         mapsize += shdr[i].sh_size;
  654                         break;
  655                 }
  656         }
  657 
  658         /*
  659          * We know how much space we need for the text/data/bss/etc.
  660          * This stuff needs to be in a single chunk so that profiling etc
  661          * can get the bounds and gdb can associate offsets with modules
  662          */
  663         ef->object = vm_object_allocate(OBJT_DEFAULT,
  664             round_page(mapsize) >> PAGE_SHIFT);
  665         if (ef->object == NULL) {
  666                 error = ENOMEM;
  667                 goto out;
  668         }
  669         ef->address = (caddr_t) vm_map_min(kernel_map);
  670 
  671         /*
  672          * In order to satisfy amd64's architectural requirements on the
  673          * location of code and data in the kernel's address space, request a
  674          * mapping that is above the kernel.  
  675          */
  676         mapbase = KERNBASE;
  677         error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
  678             round_page(mapsize), TRUE, VM_PROT_ALL, VM_PROT_ALL, FALSE);
  679         if (error) {
  680                 vm_object_deallocate(ef->object);
  681                 ef->object = 0;
  682                 goto out;
  683         }
  684 
  685         /* Wire the pages */
  686         error = vm_map_wire(kernel_map, mapbase,
  687             mapbase + round_page(mapsize),
  688             VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
  689         if (error != KERN_SUCCESS) {
  690                 error = ENOMEM;
  691                 goto out;
  692         }
  693 
  694         /* Inform the kld system about the situation */
  695         lf->address = ef->address = (caddr_t)mapbase;
  696         lf->size = mapsize;
  697 
  698         /*
  699          * Now load code/data(progbits), zero bss(nobits), allocate space for
  700          * and load relocs
  701          */
  702         pb = 0;
  703         rl = 0;
  704         ra = 0;
  705         alignmask = 0;
  706         for (i = 0; i < hdr->e_shnum; i++) {
  707                 switch (shdr[i].sh_type) {
  708                 case SHT_PROGBITS:
  709                 case SHT_NOBITS:
  710                         alignmask = shdr[i].sh_addralign - 1;
  711                         mapbase += alignmask;
  712                         mapbase &= ~alignmask;
  713                         ef->progtab[pb].addr = (void *)(uintptr_t)mapbase;
  714                         if (shdr[i].sh_type == SHT_PROGBITS) {
  715                                 ef->progtab[pb].name = "<<PROGBITS>>";
  716                                 error = vn_rdwr(UIO_READ, nd.ni_vp,
  717                                     ef->progtab[pb].addr,
  718                                     shdr[i].sh_size, shdr[i].sh_offset,
  719                                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
  720                                     NOCRED, &resid, td);
  721                                 if (error)
  722                                         goto out;
  723                                 if (resid != 0){
  724                                         error = EINVAL;
  725                                         goto out;
  726                                 }
  727                         } else {
  728                                 ef->progtab[pb].name = "<<NOBITS>>";
  729                                 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
  730                         }
  731                         ef->progtab[pb].size = shdr[i].sh_size;
  732                         ef->progtab[pb].sec = i;
  733                         if (ef->shstrtab && shdr[i].sh_name != 0)
  734                                 ef->progtab[pb].name =
  735                                     ef->shstrtab + shdr[i].sh_name;
  736 
  737                         /* Update all symbol values with the offset. */
  738                         for (j = 0; j < ef->ddbsymcnt; j++) {
  739                                 es = &ef->ddbsymtab[j];
  740                                 if (es->st_shndx != i)
  741                                         continue;
  742                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
  743                         }
  744                         mapbase += shdr[i].sh_size;
  745                         pb++;
  746                         break;
  747                 case SHT_REL:
  748                         ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
  749                             M_WAITOK);
  750                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
  751                         ef->reltab[rl].sec = shdr[i].sh_info;
  752                         error = vn_rdwr(UIO_READ, nd.ni_vp,
  753                             (void *)ef->reltab[rl].rel,
  754                             shdr[i].sh_size, shdr[i].sh_offset,
  755                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
  756                             &resid, td);
  757                         if (error)
  758                                 goto out;
  759                         if (resid != 0){
  760                                 error = EINVAL;
  761                                 goto out;
  762                         }
  763                         rl++;
  764                         break;
  765                 case SHT_RELA:
  766                         ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
  767                             M_WAITOK);
  768                         ef->relatab[ra].nrela =
  769                             shdr[i].sh_size / sizeof(Elf_Rela);
  770                         ef->relatab[ra].sec = shdr[i].sh_info;
  771                         error = vn_rdwr(UIO_READ, nd.ni_vp,
  772                             (void *)ef->relatab[ra].rela,
  773                             shdr[i].sh_size, shdr[i].sh_offset,
  774                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
  775                             &resid, td);
  776                         if (error)
  777                                 goto out;
  778                         if (resid != 0){
  779                                 error = EINVAL;
  780                                 goto out;
  781                         }
  782                         ra++;
  783                         break;
  784                 }
  785         }
  786         if (pb != ef->nprogtab)
  787                 panic("lost progbits");
  788         if (rl != ef->nreltab)
  789                 panic("lost reltab");
  790         if (ra != ef->nrelatab)
  791                 panic("lost relatab");
  792         if (mapbase != (vm_offset_t)ef->address + mapsize)
  793                 panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
  794                     mapbase, ef->address, mapsize,
  795                     (vm_offset_t)ef->address + mapsize);
  796 
  797         /* Local intra-module relocations */
  798         link_elf_reloc_local(lf);
  799 
  800         /* Pull in dependencies */
  801         VOP_UNLOCK(nd.ni_vp, 0, td);
  802         error = linker_load_dependencies(lf);
  803         vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY, td);
  804         if (error)
  805                 goto out;
  806 
  807         /* External relocations */
  808         error = relocate_file(ef);
  809         if (error)
  810                 goto out;
  811 
  812         /* Notify MD code that a module is being loaded. */
  813         error = elf_cpu_load_file(lf);
  814         if (error)
  815                 goto out;
  816 
  817         *result = lf;
  818 
  819 out:
  820         if (error && lf)
  821                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
  822         if (hdr)
  823                 free(hdr, M_LINKER);
  824         VOP_UNLOCK(nd.ni_vp, 0, td);
  825         vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
  826         VFS_UNLOCK_GIANT(vfslocked);
  827 
  828         return error;
  829 }
  830 
  831 static void
  832 link_elf_unload_file(linker_file_t file)
  833 {
  834         elf_file_t ef = (elf_file_t) file;
  835         int i;
  836 
  837         /* Notify MD code that a module is being unloaded. */
  838         elf_cpu_unload_file(file);
  839 
  840         if (ef->preloaded) {
  841                 if (ef->reltab)
  842                         free(ef->reltab, M_LINKER);
  843                 if (ef->relatab)
  844                         free(ef->relatab, M_LINKER);
  845                 if (ef->progtab)
  846                         free(ef->progtab, M_LINKER);
  847                 if (ef->ctftab)
  848                         free(ef->ctftab, M_LINKER);
  849                 if (ef->ctfoff)
  850                         free(ef->ctfoff, M_LINKER);
  851                 if (ef->typoff)
  852                         free(ef->typoff, M_LINKER);
  853                 if (file->filename != NULL)
  854                         preload_delete_name(file->filename);
  855                 /* XXX reclaim module memory? */
  856                 return;
  857         }
  858 
  859         for (i = 0; i < ef->nreltab; i++)
  860                 if (ef->reltab[i].rel)
  861                         free(ef->reltab[i].rel, M_LINKER);
  862         for (i = 0; i < ef->nrelatab; i++)
  863                 if (ef->relatab[i].rela)
  864                         free(ef->relatab[i].rela, M_LINKER);
  865         if (ef->reltab)
  866                 free(ef->reltab, M_LINKER);
  867         if (ef->relatab)
  868                 free(ef->relatab, M_LINKER);
  869         if (ef->progtab)
  870                 free(ef->progtab, M_LINKER);
  871 
  872         if (ef->object) {
  873                 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
  874                     (vm_offset_t) ef->address +
  875                     (ef->object->size << PAGE_SHIFT));
  876         }
  877         if (ef->e_shdr)
  878                 free(ef->e_shdr, M_LINKER);
  879         if (ef->ddbsymtab)
  880                 free(ef->ddbsymtab, M_LINKER);
  881         if (ef->ddbstrtab)
  882                 free(ef->ddbstrtab, M_LINKER);
  883         if (ef->shstrtab)
  884                 free(ef->shstrtab, M_LINKER);
  885         if (ef->ctftab)
  886                 free(ef->ctftab, M_LINKER);
  887         if (ef->ctfoff)
  888                 free(ef->ctfoff, M_LINKER);
  889         if (ef->typoff)
  890                 free(ef->typoff, M_LINKER);
  891 }
  892 
  893 static const char *
  894 symbol_name(elf_file_t ef, Elf_Size r_info)
  895 {
  896         const Elf_Sym *ref;
  897 
  898         if (ELF_R_SYM(r_info)) {
  899                 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
  900                 return ef->ddbstrtab + ref->st_name;
  901         } else
  902                 return NULL;
  903 }
  904 
  905 static Elf_Addr
  906 findbase(elf_file_t ef, int sec)
  907 {
  908         int i;
  909         Elf_Addr base = 0;
  910 
  911         for (i = 0; i < ef->nprogtab; i++) {
  912                 if (sec == ef->progtab[i].sec) {
  913                         base = (Elf_Addr)ef->progtab[i].addr;
  914                         break;
  915                 }
  916         }
  917         return base;
  918 }
  919 
  920 static int
  921 relocate_file(elf_file_t ef)
  922 {
  923         const Elf_Rel *rellim;
  924         const Elf_Rel *rel;
  925         const Elf_Rela *relalim;
  926         const Elf_Rela *rela;
  927         const char *symname;
  928         const Elf_Sym *sym;
  929         int i;
  930         Elf_Size symidx;
  931         Elf_Addr base;
  932 
  933 
  934         /* Perform relocations without addend if there are any: */
  935         for (i = 0; i < ef->nreltab; i++) {
  936                 rel = ef->reltab[i].rel;
  937                 if (rel == NULL)
  938                         panic("lost a reltab!");
  939                 rellim = rel + ef->reltab[i].nrel;
  940                 base = findbase(ef, ef->reltab[i].sec);
  941                 if (base == 0)
  942                         panic("lost base for reltab");
  943                 for ( ; rel < rellim; rel++) {
  944                         symidx = ELF_R_SYM(rel->r_info);
  945                         if (symidx >= ef->ddbsymcnt)
  946                                 continue;
  947                         sym = ef->ddbsymtab + symidx;
  948                         /* Local relocs are already done */
  949                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
  950                                 continue;
  951                         if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
  952                             elf_obj_lookup)) {
  953                                 symname = symbol_name(ef, rel->r_info);
  954                                 printf("link_elf_obj: symbol %s undefined\n",
  955                                     symname);
  956                                 return ENOENT;
  957                         }
  958                 }
  959         }
  960 
  961         /* Perform relocations with addend if there are any: */
  962         for (i = 0; i < ef->nrelatab; i++) {
  963                 rela = ef->relatab[i].rela;
  964                 if (rela == NULL)
  965                         panic("lost a relatab!");
  966                 relalim = rela + ef->relatab[i].nrela;
  967                 base = findbase(ef, ef->relatab[i].sec);
  968                 if (base == 0)
  969                         panic("lost base for relatab");
  970                 for ( ; rela < relalim; rela++) {
  971                         symidx = ELF_R_SYM(rela->r_info);
  972                         if (symidx >= ef->ddbsymcnt)
  973                                 continue;
  974                         sym = ef->ddbsymtab + symidx;
  975                         /* Local relocs are already done */
  976                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
  977                                 continue;
  978                         if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
  979                             elf_obj_lookup)) {
  980                                 symname = symbol_name(ef, rela->r_info);
  981                                 printf("link_elf_obj: symbol %s undefined\n",
  982                                     symname);
  983                                 return ENOENT;
  984                         }
  985                 }
  986         }
  987 
  988         return 0;
  989 }
  990 
  991 static int
  992 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
  993 {
  994         elf_file_t ef = (elf_file_t) lf;
  995         const Elf_Sym *symp;
  996         const char *strp;
  997         int i;
  998 
  999         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
 1000                 strp = ef->ddbstrtab + symp->st_name;
 1001                 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
 1002                         *sym = (c_linker_sym_t) symp;
 1003                         return 0;
 1004                 }
 1005         }
 1006         return ENOENT;
 1007 }
 1008 
 1009 static int
 1010 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
 1011     linker_symval_t *symval)
 1012 {
 1013         elf_file_t ef = (elf_file_t) lf;
 1014         const Elf_Sym *es = (const Elf_Sym*) sym;
 1015 
 1016         if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
 1017                 symval->name = ef->ddbstrtab + es->st_name;
 1018                 symval->value = (caddr_t)es->st_value;
 1019                 symval->size = es->st_size;
 1020                 return 0;
 1021         }
 1022         return ENOENT;
 1023 }
 1024 
 1025 static int
 1026 link_elf_search_symbol(linker_file_t lf, caddr_t value,
 1027     c_linker_sym_t *sym, long *diffp)
 1028 {
 1029         elf_file_t ef = (elf_file_t) lf;
 1030         u_long off = (uintptr_t) (void *) value;
 1031         u_long diff = off;
 1032         u_long st_value;
 1033         const Elf_Sym *es;
 1034         const Elf_Sym *best = 0;
 1035         int i;
 1036 
 1037         for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
 1038                 if (es->st_name == 0)
 1039                         continue;
 1040                 st_value = es->st_value;
 1041                 if (off >= st_value) {
 1042                         if (off - st_value < diff) {
 1043                                 diff = off - st_value;
 1044                                 best = es;
 1045                                 if (diff == 0)
 1046                                         break;
 1047                         } else if (off - st_value == diff) {
 1048                                 best = es;
 1049                         }
 1050                 }
 1051         }
 1052         if (best == 0)
 1053                 *diffp = off;
 1054         else
 1055                 *diffp = diff;
 1056         *sym = (c_linker_sym_t) best;
 1057 
 1058         return 0;
 1059 }
 1060 
 1061 /*
 1062  * Look up a linker set on an ELF system.
 1063  */
 1064 static int
 1065 link_elf_lookup_set(linker_file_t lf, const char *name,
 1066     void ***startp, void ***stopp, int *countp)
 1067 {
 1068         elf_file_t ef = (elf_file_t)lf;
 1069         void **start, **stop;
 1070         int i, count;
 1071 
 1072         /* Relative to section number */
 1073         for (i = 0; i < ef->nprogtab; i++) {
 1074                 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
 1075                     strcmp(ef->progtab[i].name + 4, name) == 0) {
 1076                         start  = (void **)ef->progtab[i].addr;
 1077                         stop = (void **)((char *)ef->progtab[i].addr +
 1078                             ef->progtab[i].size);
 1079                         count = stop - start;
 1080                         if (startp)
 1081                                 *startp = start;
 1082                         if (stopp)
 1083                                 *stopp = stop;
 1084                         if (countp)
 1085                                 *countp = count;
 1086                         return (0);
 1087                 }
 1088         }
 1089         return (ESRCH);
 1090 }
 1091 
 1092 static int
 1093 link_elf_each_function_name(linker_file_t file,
 1094     int (*callback)(const char *, void *), void *opaque)
 1095 {
 1096         elf_file_t ef = (elf_file_t)file;
 1097         const Elf_Sym *symp;
 1098         int i, error;
 1099         
 1100         /* Exhaustive search */
 1101         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
 1102                 if (symp->st_value != 0 &&
 1103                     ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
 1104                         error = callback(ef->ddbstrtab + symp->st_name, opaque);
 1105                         if (error)
 1106                                 return (error);
 1107                 }
 1108         }
 1109         return (0);
 1110 }
 1111 
 1112 static int
 1113 link_elf_each_function_nameval(linker_file_t file,
 1114     linker_function_nameval_callback_t callback, void *opaque)
 1115 {
 1116         linker_symval_t symval;
 1117         elf_file_t ef = (elf_file_t)file;
 1118         const Elf_Sym* symp;
 1119         int i, error;
 1120 
 1121         /* Exhaustive search */
 1122         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
 1123                 if (symp->st_value != 0 &&
 1124                     ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
 1125                         error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
 1126                         if (error)
 1127                                 return (error);
 1128                         error = callback(file, i, &symval, opaque);
 1129                         if (error)
 1130                                 return (error);
 1131                 }
 1132         }
 1133         return (0);
 1134 }
 1135 
 1136 /*
 1137  * Symbol lookup function that can be used when the symbol index is known (ie
 1138  * in relocations). It uses the symbol index instead of doing a fully fledged
 1139  * hash table based lookup when such is valid. For example for local symbols.
 1140  * This is not only more efficient, it's also more correct. It's not always
 1141  * the case that the symbol can be found through the hash table.
 1142  */
 1143 static Elf_Addr
 1144 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps)
 1145 {
 1146         elf_file_t ef = (elf_file_t)lf;
 1147         const Elf_Sym *sym;
 1148         const char *symbol;
 1149         Elf_Addr ret;
 1150 
 1151         /* Don't even try to lookup the symbol if the index is bogus. */
 1152         if (symidx >= ef->ddbsymcnt)
 1153                 return (0);
 1154 
 1155         sym = ef->ddbsymtab + symidx;
 1156 
 1157         /* Quick answer if there is a definition included. */
 1158         if (sym->st_shndx != SHN_UNDEF)
 1159                 return (sym->st_value);
 1160 
 1161         /* If we get here, then it is undefined and needs a lookup. */
 1162         switch (ELF_ST_BIND(sym->st_info)) {
 1163         case STB_LOCAL:
 1164                 /* Local, but undefined? huh? */
 1165                 return (0);
 1166 
 1167         case STB_GLOBAL:
 1168                 /* Relative to Data or Function name */
 1169                 symbol = ef->ddbstrtab + sym->st_name;
 1170 
 1171                 /* Force a lookup failure if the symbol name is bogus. */
 1172                 if (*symbol == 0)
 1173                         return (0);
 1174                 ret = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
 1175                 return ret;
 1176 
 1177         case STB_WEAK:
 1178                 printf("link_elf_obj: Weak symbols not supported\n");
 1179                 return (0);
 1180 
 1181         default:
 1182                 return (0);
 1183         }
 1184 }
 1185 
 1186 static void
 1187 link_elf_fix_link_set(elf_file_t ef)
 1188 {
 1189         static const char startn[] = "__start_";
 1190         static const char stopn[] = "__stop_";
 1191         Elf_Sym *sym;
 1192         const char *sym_name, *linkset_name;
 1193         Elf_Addr startp, stopp;
 1194         Elf_Size symidx;
 1195         int start, i;
 1196 
 1197         startp = stopp = 0;
 1198         for (symidx = 1 /* zero entry is special */;
 1199                 symidx < ef->ddbsymcnt; symidx++) {
 1200                 sym = ef->ddbsymtab + symidx;
 1201                 if (sym->st_shndx != SHN_UNDEF)
 1202                         continue;
 1203 
 1204                 sym_name = ef->ddbstrtab + sym->st_name;
 1205                 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
 1206                         start = 1;
 1207                         linkset_name = sym_name + sizeof(startn) - 1;
 1208                 }
 1209                 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
 1210                         start = 0;
 1211                         linkset_name = sym_name + sizeof(stopn) - 1;
 1212                 }
 1213                 else
 1214                         continue;
 1215 
 1216                 for (i = 0; i < ef->nprogtab; i++) {
 1217                         if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
 1218                                 startp = (Elf_Addr)ef->progtab[i].addr;
 1219                                 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
 1220                                 break;
 1221                         }
 1222                 }
 1223                 if (i == ef->nprogtab)
 1224                         continue;
 1225 
 1226                 sym->st_value = start ? startp : stopp;
 1227                 sym->st_shndx = i;
 1228         }
 1229 }
 1230 
 1231 static void
 1232 link_elf_reloc_local(linker_file_t lf)
 1233 {
 1234         elf_file_t ef = (elf_file_t)lf;
 1235         const Elf_Rel *rellim;
 1236         const Elf_Rel *rel;
 1237         const Elf_Rela *relalim;
 1238         const Elf_Rela *rela;
 1239         const Elf_Sym *sym;
 1240         Elf_Addr base;
 1241         int i;
 1242         Elf_Size symidx;
 1243 
 1244         link_elf_fix_link_set(ef);
 1245 
 1246         /* Perform relocations without addend if there are any: */
 1247         for (i = 0; i < ef->nreltab; i++) {
 1248                 rel = ef->reltab[i].rel;
 1249                 if (rel == NULL)
 1250                         panic("lost a reltab!");
 1251                 rellim = rel + ef->reltab[i].nrel;
 1252                 base = findbase(ef, ef->reltab[i].sec);
 1253                 if (base == 0)
 1254                         panic("lost base for reltab");
 1255                 for ( ; rel < rellim; rel++) {
 1256                         symidx = ELF_R_SYM(rel->r_info);
 1257                         if (symidx >= ef->ddbsymcnt)
 1258                                 continue;
 1259                         sym = ef->ddbsymtab + symidx;
 1260                         /* Only do local relocs */
 1261                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
 1262                                 continue;
 1263                         elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
 1264                             elf_obj_lookup);
 1265                 }
 1266         }
 1267 
 1268         /* Perform relocations with addend if there are any: */
 1269         for (i = 0; i < ef->nrelatab; i++) {
 1270                 rela = ef->relatab[i].rela;
 1271                 if (rela == NULL)
 1272                         panic("lost a relatab!");
 1273                 relalim = rela + ef->relatab[i].nrela;
 1274                 base = findbase(ef, ef->relatab[i].sec);
 1275                 if (base == 0)
 1276                         panic("lost base for relatab");
 1277                 for ( ; rela < relalim; rela++) {
 1278                         symidx = ELF_R_SYM(rela->r_info);
 1279                         if (symidx >= ef->ddbsymcnt)
 1280                                 continue;
 1281                         sym = ef->ddbsymtab + symidx;
 1282                         /* Only do local relocs */
 1283                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
 1284                                 continue;
 1285                         elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
 1286                             elf_obj_lookup);
 1287                 }
 1288         }
 1289 }

Cache object: 56139b392e44e80c81093975ad56045e


[ 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.