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


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

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    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 
   33 #include <sys/param.h>
   34 #include <sys/systm.h>
   35 #include <sys/kernel.h>
   36 #include <sys/lock.h>
   37 #include <sys/malloc.h>
   38 #include <sys/mutex.h>
   39 #include <sys/mount.h>
   40 #include <sys/proc.h>
   41 #include <sys/namei.h>
   42 #include <sys/fcntl.h>
   43 #include <sys/vnode.h>
   44 #include <sys/linker.h>
   45 
   46 #include <machine/elf.h>
   47 
   48 #include <net/vnet.h>
   49 
   50 #include <security/mac/mac_framework.h>
   51 
   52 #include <vm/vm.h>
   53 #include <vm/vm_param.h>
   54 #include <vm/vm_object.h>
   55 #include <vm/vm_kern.h>
   56 #include <vm/vm_extern.h>
   57 #include <vm/pmap.h>
   58 #include <vm/vm_map.h>
   59 
   60 #include <sys/link_elf.h>
   61 
   62 #ifdef DDB_CTF
   63 #include <net/zlib.h>
   64 #endif
   65 
   66 #include "linker_if.h"
   67 
   68 typedef struct {
   69         void            *addr;
   70         Elf_Off         size;
   71         int             flags;
   72         int             sec;    /* Original section */
   73         char            *name;
   74 } Elf_progent;
   75 
   76 typedef struct {
   77         Elf_Rel         *rel;
   78         int             nrel;
   79         int             sec;
   80 } Elf_relent;
   81 
   82 typedef struct {
   83         Elf_Rela        *rela;
   84         int             nrela;
   85         int             sec;
   86 } Elf_relaent;
   87 
   88 
   89 typedef struct elf_file {
   90         struct linker_file lf;          /* Common fields */
   91 
   92         int             preloaded;
   93         caddr_t         address;        /* Relocation address */
   94         vm_object_t     object;         /* VM object to hold file pages */
   95         Elf_Shdr        *e_shdr;
   96 
   97         Elf_progent     *progtab;
   98         int             nprogtab;
   99 
  100         Elf_relaent     *relatab;
  101         int             nrelatab;
  102 
  103         Elf_relent      *reltab;
  104         int             nreltab;
  105 
  106         Elf_Sym         *ddbsymtab;     /* The symbol table we are using */
  107         long            ddbsymcnt;      /* Number of symbols */
  108         caddr_t         ddbstrtab;      /* String table */
  109         long            ddbstrcnt;      /* number of bytes in string table */
  110 
  111         caddr_t         shstrtab;       /* Section name string table */
  112         long            shstrcnt;       /* number of bytes in string table */
  113 
  114         caddr_t         ctftab;         /* CTF table */
  115         long            ctfcnt;         /* number of bytes in CTF table */
  116         caddr_t         ctfoff;         /* CTF offset table */
  117         caddr_t         typoff;         /* Type offset table */
  118         long            typlen;         /* Number of type entries. */
  119 
  120 } *elf_file_t;
  121 
  122 #include <kern/kern_ctf.c>
  123 
  124 static int      link_elf_link_preload(linker_class_t cls,
  125                     const char *, linker_file_t *);
  126 static int      link_elf_link_preload_finish(linker_file_t);
  127 static int      link_elf_load_file(linker_class_t, const char *, linker_file_t *);
  128 static int      link_elf_lookup_symbol(linker_file_t, const char *,
  129                     c_linker_sym_t *);
  130 static int      link_elf_symbol_values(linker_file_t, c_linker_sym_t,
  131                     linker_symval_t *);
  132 static int      link_elf_search_symbol(linker_file_t, caddr_t value,
  133                     c_linker_sym_t *sym, long *diffp);
  134 
  135 static void     link_elf_unload_file(linker_file_t);
  136 static int      link_elf_lookup_set(linker_file_t, const char *,
  137                     void ***, void ***, int *);
  138 static int      link_elf_each_function_name(linker_file_t,
  139                     int (*)(const char *, void *), void *);
  140 static int      link_elf_each_function_nameval(linker_file_t,
  141                                 linker_function_nameval_callback_t,
  142                                 void *);
  143 static void     link_elf_reloc_local(linker_file_t);
  144 static long     link_elf_symtab_get(linker_file_t, const Elf_Sym **);
  145 static long     link_elf_strtab_get(linker_file_t, caddr_t *);
  146 
  147 static Elf_Addr elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps);
  148 
  149 static kobj_method_t link_elf_methods[] = {
  150         KOBJMETHOD(linker_lookup_symbol,        link_elf_lookup_symbol),
  151         KOBJMETHOD(linker_symbol_values,        link_elf_symbol_values),
  152         KOBJMETHOD(linker_search_symbol,        link_elf_search_symbol),
  153         KOBJMETHOD(linker_unload,               link_elf_unload_file),
  154         KOBJMETHOD(linker_load_file,            link_elf_load_file),
  155         KOBJMETHOD(linker_link_preload,         link_elf_link_preload),
  156         KOBJMETHOD(linker_link_preload_finish,  link_elf_link_preload_finish),
  157         KOBJMETHOD(linker_lookup_set,           link_elf_lookup_set),
  158         KOBJMETHOD(linker_each_function_name,   link_elf_each_function_name),
  159         KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
  160         KOBJMETHOD(linker_ctf_get,              link_elf_ctf_get),
  161         KOBJMETHOD(linker_symtab_get,           link_elf_symtab_get),
  162         KOBJMETHOD(linker_strtab_get,           link_elf_strtab_get),
  163         { 0, 0 }
  164 };
  165 
  166 static struct linker_class link_elf_class = {
  167 #if ELF_TARG_CLASS == ELFCLASS32
  168         "elf32_obj",
  169 #else
  170         "elf64_obj",
  171 #endif
  172         link_elf_methods, sizeof(struct elf_file)
  173 };
  174 
  175 static int      relocate_file(elf_file_t ef);
  176 
  177 static void
  178 link_elf_error(const char *filename, const char *s)
  179 {
  180         if (filename == NULL)
  181                 printf("kldload: %s\n", s);
  182         else
  183                 printf("kldload: %s: %s\n", filename, s);
  184 }
  185 
  186 static void
  187 link_elf_init(void *arg)
  188 {
  189 
  190         linker_add_class(&link_elf_class);
  191 }
  192 
  193 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, 0);
  194 
  195 static int
  196 link_elf_link_preload(linker_class_t cls, const char *filename,
  197     linker_file_t *result)
  198 {
  199         Elf_Ehdr *hdr;
  200         Elf_Shdr *shdr;
  201         Elf_Sym *es;
  202         void *modptr, *baseptr, *sizeptr;
  203         char *type;
  204         elf_file_t ef;
  205         linker_file_t lf;
  206         Elf_Addr off;
  207         int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex;
  208 
  209         /* Look to see if we have the file preloaded */
  210         modptr = preload_search_by_name(filename);
  211         if (modptr == NULL)
  212                 return ENOENT;
  213 
  214         type = (char *)preload_search_info(modptr, MODINFO_TYPE);
  215         baseptr = preload_search_info(modptr, MODINFO_ADDR);
  216         sizeptr = preload_search_info(modptr, MODINFO_SIZE);
  217         hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA |
  218             MODINFOMD_ELFHDR);
  219         shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA |
  220             MODINFOMD_SHDR);
  221         if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE)
  222             " obj module") != 0 &&
  223             strcmp(type, "elf obj module") != 0)) {
  224                 return (EFTYPE);
  225         }
  226         if (baseptr == NULL || sizeptr == NULL || hdr == NULL ||
  227             shdr == NULL)
  228                 return (EINVAL);
  229 
  230         lf = linker_make_file(filename, &link_elf_class);
  231         if (lf == NULL)
  232                 return (ENOMEM);
  233 
  234         ef = (elf_file_t)lf;
  235         ef->preloaded = 1;
  236         ef->address = *(caddr_t *)baseptr;
  237         lf->address = *(caddr_t *)baseptr;
  238         lf->size = *(size_t *)sizeptr;
  239 
  240         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
  241             hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
  242             hdr->e_ident[EI_VERSION] != EV_CURRENT ||
  243             hdr->e_version != EV_CURRENT ||
  244             hdr->e_type != ET_REL ||
  245             hdr->e_machine != ELF_TARG_MACH) {
  246                 error = EFTYPE;
  247                 goto out;
  248         }
  249         ef->e_shdr = shdr;
  250 
  251         /* Scan the section header for information and table sizing. */
  252         symtabindex = -1;
  253         symstrindex = -1;
  254         for (i = 0; i < hdr->e_shnum; i++) {
  255                 switch (shdr[i].sh_type) {
  256                 case SHT_PROGBITS:
  257                 case SHT_NOBITS:
  258 #ifdef __amd64__
  259                 case SHT_AMD64_UNWIND:
  260 #endif
  261                         ef->nprogtab++;
  262                         break;
  263                 case SHT_SYMTAB:
  264                         symtabindex = i;
  265                         symstrindex = shdr[i].sh_link;
  266                         break;
  267                 case SHT_REL:
  268                         ef->nreltab++;
  269                         break;
  270                 case SHT_RELA:
  271                         ef->nrelatab++;
  272                         break;
  273                 }
  274         }
  275 
  276         shstrindex = hdr->e_shstrndx;
  277         if (ef->nprogtab == 0 || symstrindex < 0 ||
  278             symstrindex >= hdr->e_shnum ||
  279             shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
  280             shstrindex >= hdr->e_shnum ||
  281             shdr[shstrindex].sh_type != SHT_STRTAB) {
  282                 printf("%s: bad/missing section headers\n", filename);
  283                 error = ENOEXEC;
  284                 goto out;
  285         }
  286 
  287         /* Allocate space for tracking the load chunks */
  288         if (ef->nprogtab != 0)
  289                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
  290                     M_LINKER, M_WAITOK | M_ZERO);
  291         if (ef->nreltab != 0)
  292                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
  293                     M_LINKER, M_WAITOK | M_ZERO);
  294         if (ef->nrelatab != 0)
  295                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
  296                     M_LINKER, M_WAITOK | M_ZERO);
  297         if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
  298             (ef->nreltab != 0 && ef->reltab == NULL) ||
  299             (ef->nrelatab != 0 && ef->relatab == NULL)) {
  300                 error = ENOMEM;
  301                 goto out;
  302         }
  303 
  304         /* XXX, relocate the sh_addr fields saved by the loader. */
  305         off = 0;
  306         for (i = 0; i < hdr->e_shnum; i++) {
  307                 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
  308                         off = shdr[i].sh_addr;
  309         }
  310         for (i = 0; i < hdr->e_shnum; i++) {
  311                 if (shdr[i].sh_addr != 0)
  312                         shdr[i].sh_addr = shdr[i].sh_addr - off +
  313                             (Elf_Addr)ef->address;
  314         }
  315 
  316         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
  317         ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
  318         ef->ddbstrcnt = shdr[symstrindex].sh_size;
  319         ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
  320         ef->shstrcnt = shdr[shstrindex].sh_size;
  321         ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
  322 
  323         /* Now fill out progtab and the relocation tables. */
  324         pb = 0;
  325         rl = 0;
  326         ra = 0;
  327         for (i = 0; i < hdr->e_shnum; i++) {
  328                 switch (shdr[i].sh_type) {
  329                 case SHT_PROGBITS:
  330                 case SHT_NOBITS:
  331 #ifdef __amd64__
  332                 case SHT_AMD64_UNWIND:
  333 #endif
  334                         ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
  335                         if (shdr[i].sh_type == SHT_PROGBITS)
  336                                 ef->progtab[pb].name = "<<PROGBITS>>";
  337 #ifdef __amd64__
  338                         else if (shdr[i].sh_type == SHT_AMD64_UNWIND)
  339                                 ef->progtab[pb].name = "<<UNWIND>>";
  340 #endif
  341                         else
  342                                 ef->progtab[pb].name = "<<NOBITS>>";
  343                         ef->progtab[pb].size = shdr[i].sh_size;
  344                         ef->progtab[pb].sec = i;
  345                         if (ef->shstrtab && shdr[i].sh_name != 0)
  346                                 ef->progtab[pb].name =
  347                                     ef->shstrtab + shdr[i].sh_name;
  348                         if (ef->progtab[pb].name != NULL && 
  349                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
  350                                 void *dpcpu;
  351 
  352                                 dpcpu = dpcpu_alloc(shdr[i].sh_size);
  353                                 if (dpcpu == NULL) {
  354                                         error = ENOSPC;
  355                                         goto out;
  356                                 }
  357                                 memcpy(dpcpu, ef->progtab[pb].addr,
  358                                     ef->progtab[pb].size);
  359                                 dpcpu_copy(dpcpu, shdr[i].sh_size);
  360                                 ef->progtab[pb].addr = dpcpu;
  361 #ifdef VIMAGE
  362                         } else if (ef->progtab[pb].name != NULL &&
  363                             !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
  364                                 void *vnet_data;
  365 
  366                                 vnet_data = vnet_data_alloc(shdr[i].sh_size);
  367                                 if (vnet_data == NULL) {
  368                                         error = ENOSPC;
  369                                         goto out;
  370                                 }
  371                                 memcpy(vnet_data, ef->progtab[pb].addr,
  372                                     ef->progtab[pb].size);
  373                                 vnet_data_copy(vnet_data, shdr[i].sh_size);
  374                                 ef->progtab[pb].addr = vnet_data;
  375 #endif
  376                         }
  377 
  378                         /* Update all symbol values with the offset. */
  379                         for (j = 0; j < ef->ddbsymcnt; j++) {
  380                                 es = &ef->ddbsymtab[j];
  381                                 if (es->st_shndx != i)
  382                                         continue;
  383                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
  384                         }
  385                         pb++;
  386                         break;
  387                 case SHT_REL:
  388                         ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
  389                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
  390                         ef->reltab[rl].sec = shdr[i].sh_info;
  391                         rl++;
  392                         break;
  393                 case SHT_RELA:
  394                         ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
  395                         ef->relatab[ra].nrela =
  396                             shdr[i].sh_size / sizeof(Elf_Rela);
  397                         ef->relatab[ra].sec = shdr[i].sh_info;
  398                         ra++;
  399                         break;
  400                 }
  401         }
  402         if (pb != ef->nprogtab)
  403                 panic("lost progbits");
  404         if (rl != ef->nreltab)
  405                 panic("lost reltab");
  406         if (ra != ef->nrelatab)
  407                 panic("lost relatab");
  408 
  409         /* Local intra-module relocations */
  410         link_elf_reloc_local(lf);
  411 
  412         *result = lf;
  413         return (0);
  414 
  415 out:
  416         /* preload not done this way */
  417         linker_file_unload(lf, LINKER_UNLOAD_FORCE);
  418         return (error);
  419 }
  420 
  421 static int
  422 link_elf_link_preload_finish(linker_file_t lf)
  423 {
  424         elf_file_t ef;
  425         int error;
  426 
  427         ef = (elf_file_t)lf;
  428         error = relocate_file(ef);
  429         if (error)
  430                 return error;
  431 
  432         /* Notify MD code that a module is being loaded. */
  433         error = elf_cpu_load_file(lf);
  434         if (error)
  435                 return (error);
  436 
  437         return (0);
  438 }
  439 
  440 static int
  441 link_elf_load_file(linker_class_t cls, const char *filename,
  442     linker_file_t *result)
  443 {
  444         struct nameidata nd;
  445         struct thread *td = curthread;  /* XXX */
  446         Elf_Ehdr *hdr;
  447         Elf_Shdr *shdr;
  448         Elf_Sym *es;
  449         int nbytes, i, j;
  450         vm_offset_t mapbase;
  451         size_t mapsize;
  452         int error = 0;
  453         ssize_t resid;
  454         int flags;
  455         elf_file_t ef;
  456         linker_file_t lf;
  457         int symtabindex;
  458         int symstrindex;
  459         int shstrindex;
  460         int nsym;
  461         int pb, rl, ra;
  462         int alignmask;
  463         int vfslocked;
  464 
  465         shdr = NULL;
  466         lf = NULL;
  467         mapsize = 0;
  468         hdr = NULL;
  469 
  470         NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, filename, td);
  471         flags = FREAD;
  472         error = vn_open(&nd, &flags, 0, NULL);
  473         if (error)
  474                 return error;
  475         vfslocked = NDHASGIANT(&nd);
  476         NDFREE(&nd, NDF_ONLY_PNBUF);
  477         if (nd.ni_vp->v_type != VREG) {
  478                 error = ENOEXEC;
  479                 goto out;
  480         }
  481 #ifdef MAC
  482         error = mac_kld_check_load(td->td_ucred, nd.ni_vp);
  483         if (error) {
  484                 goto out;
  485         }
  486 #endif
  487 
  488         /* Read the elf header from the file. */
  489         hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
  490         error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
  491             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
  492             &resid, td);
  493         if (error)
  494                 goto out;
  495         if (resid != 0){
  496                 error = ENOEXEC;
  497                 goto out;
  498         }
  499 
  500         if (!IS_ELF(*hdr)) {
  501                 error = ENOEXEC;
  502                 goto out;
  503         }
  504 
  505         if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
  506             || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
  507                 link_elf_error(filename, "Unsupported file layout");
  508                 error = ENOEXEC;
  509                 goto out;
  510         }
  511         if (hdr->e_ident[EI_VERSION] != EV_CURRENT
  512             || hdr->e_version != EV_CURRENT) {
  513                 link_elf_error(filename, "Unsupported file version");
  514                 error = ENOEXEC;
  515                 goto out;
  516         }
  517         if (hdr->e_type != ET_REL) {
  518                 error = ENOSYS;
  519                 goto out;
  520         }
  521         if (hdr->e_machine != ELF_TARG_MACH) {
  522                 link_elf_error(filename, "Unsupported machine");
  523                 error = ENOEXEC;
  524                 goto out;
  525         }
  526 
  527         lf = linker_make_file(filename, &link_elf_class);
  528         if (!lf) {
  529                 error = ENOMEM;
  530                 goto out;
  531         }
  532         ef = (elf_file_t) lf;
  533         ef->nprogtab = 0;
  534         ef->e_shdr = 0;
  535         ef->nreltab = 0;
  536         ef->nrelatab = 0;
  537 
  538         /* Allocate and read in the section header */
  539         nbytes = hdr->e_shnum * hdr->e_shentsize;
  540         if (nbytes == 0 || hdr->e_shoff == 0 ||
  541             hdr->e_shentsize != sizeof(Elf_Shdr)) {
  542                 error = ENOEXEC;
  543                 goto out;
  544         }
  545         shdr = malloc(nbytes, M_LINKER, M_WAITOK);
  546         ef->e_shdr = shdr;
  547         error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
  548             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
  549         if (error)
  550                 goto out;
  551         if (resid) {
  552                 error = ENOEXEC;
  553                 goto out;
  554         }
  555 
  556         /* Scan the section header for information and table sizing. */
  557         nsym = 0;
  558         symtabindex = -1;
  559         symstrindex = -1;
  560         for (i = 0; i < hdr->e_shnum; i++) {
  561                 if (shdr[i].sh_size == 0)
  562                         continue;
  563                 switch (shdr[i].sh_type) {
  564                 case SHT_PROGBITS:
  565                 case SHT_NOBITS:
  566 #ifdef __amd64__
  567                 case SHT_AMD64_UNWIND:
  568 #endif
  569                         ef->nprogtab++;
  570                         break;
  571                 case SHT_SYMTAB:
  572                         nsym++;
  573                         symtabindex = i;
  574                         symstrindex = shdr[i].sh_link;
  575                         break;
  576                 case SHT_REL:
  577                         ef->nreltab++;
  578                         break;
  579                 case SHT_RELA:
  580                         ef->nrelatab++;
  581                         break;
  582                 case SHT_STRTAB:
  583                         break;
  584                 }
  585         }
  586         if (ef->nprogtab == 0) {
  587                 link_elf_error(filename, "file has no contents");
  588                 error = ENOEXEC;
  589                 goto out;
  590         }
  591         if (nsym != 1) {
  592                 /* Only allow one symbol table for now */
  593                 link_elf_error(filename, "file has no valid symbol table");
  594                 error = ENOEXEC;
  595                 goto out;
  596         }
  597         if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
  598             shdr[symstrindex].sh_type != SHT_STRTAB) {
  599                 link_elf_error(filename, "file has invalid symbol strings");
  600                 error = ENOEXEC;
  601                 goto out;
  602         }
  603 
  604         /* Allocate space for tracking the load chunks */
  605         if (ef->nprogtab != 0)
  606                 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
  607                     M_LINKER, M_WAITOK | M_ZERO);
  608         if (ef->nreltab != 0)
  609                 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
  610                     M_LINKER, M_WAITOK | M_ZERO);
  611         if (ef->nrelatab != 0)
  612                 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
  613                     M_LINKER, M_WAITOK | M_ZERO);
  614 
  615         if (symtabindex == -1)
  616                 panic("lost symbol table index");
  617         /* Allocate space for and load the symbol table */
  618         ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
  619         ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
  620         error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
  621             shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
  622             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
  623             &resid, td);
  624         if (error)
  625                 goto out;
  626         if (resid != 0){
  627                 error = EINVAL;
  628                 goto out;
  629         }
  630 
  631         if (symstrindex == -1)
  632                 panic("lost symbol string index");
  633         /* Allocate space for and load the symbol strings */
  634         ef->ddbstrcnt = shdr[symstrindex].sh_size;
  635         ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
  636         error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
  637             shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
  638             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
  639             &resid, td);
  640         if (error)
  641                 goto out;
  642         if (resid != 0){
  643                 error = EINVAL;
  644                 goto out;
  645         }
  646 
  647         /* Do we have a string table for the section names?  */
  648         shstrindex = -1;
  649         if (hdr->e_shstrndx != 0 &&
  650             shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
  651                 shstrindex = hdr->e_shstrndx;
  652                 ef->shstrcnt = shdr[shstrindex].sh_size;
  653                 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
  654                     M_WAITOK);
  655                 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
  656                     shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
  657                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
  658                     &resid, td);
  659                 if (error)
  660                         goto out;
  661                 if (resid != 0){
  662                         error = EINVAL;
  663                         goto out;
  664                 }
  665         }
  666 
  667         /* Size up code/data(progbits) and bss(nobits). */
  668         alignmask = 0;
  669         for (i = 0; i < hdr->e_shnum; i++) {
  670                 if (shdr[i].sh_size == 0)
  671                         continue;
  672                 switch (shdr[i].sh_type) {
  673                 case SHT_PROGBITS:
  674                 case SHT_NOBITS:
  675 #ifdef __amd64__
  676                 case SHT_AMD64_UNWIND:
  677 #endif
  678                         alignmask = shdr[i].sh_addralign - 1;
  679                         mapsize += alignmask;
  680                         mapsize &= ~alignmask;
  681                         mapsize += shdr[i].sh_size;
  682                         break;
  683                 }
  684         }
  685 
  686         /*
  687          * We know how much space we need for the text/data/bss/etc.
  688          * This stuff needs to be in a single chunk so that profiling etc
  689          * can get the bounds and gdb can associate offsets with modules
  690          */
  691         ef->object = vm_object_allocate(OBJT_DEFAULT,
  692             round_page(mapsize) >> PAGE_SHIFT);
  693         if (ef->object == NULL) {
  694                 error = ENOMEM;
  695                 goto out;
  696         }
  697         ef->address = (caddr_t) vm_map_min(kernel_map);
  698 
  699         /*
  700          * In order to satisfy amd64's architectural requirements on the
  701          * location of code and data in the kernel's address space, request a
  702          * mapping that is above the kernel.  
  703          */
  704         mapbase = KERNBASE;
  705         error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
  706             round_page(mapsize), TRUE, VM_PROT_ALL, VM_PROT_ALL, FALSE);
  707         if (error) {
  708                 vm_object_deallocate(ef->object);
  709                 ef->object = 0;
  710                 goto out;
  711         }
  712 
  713         /* Wire the pages */
  714         error = vm_map_wire(kernel_map, mapbase,
  715             mapbase + round_page(mapsize),
  716             VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
  717         if (error != KERN_SUCCESS) {
  718                 error = ENOMEM;
  719                 goto out;
  720         }
  721 
  722         /* Inform the kld system about the situation */
  723         lf->address = ef->address = (caddr_t)mapbase;
  724         lf->size = mapsize;
  725 
  726         /*
  727          * Now load code/data(progbits), zero bss(nobits), allocate space for
  728          * and load relocs
  729          */
  730         pb = 0;
  731         rl = 0;
  732         ra = 0;
  733         alignmask = 0;
  734         for (i = 0; i < hdr->e_shnum; i++) {
  735                 if (shdr[i].sh_size == 0)
  736                         continue;
  737                 switch (shdr[i].sh_type) {
  738                 case SHT_PROGBITS:
  739                 case SHT_NOBITS:
  740 #ifdef __amd64__
  741                 case SHT_AMD64_UNWIND:
  742 #endif
  743                         alignmask = shdr[i].sh_addralign - 1;
  744                         mapbase += alignmask;
  745                         mapbase &= ~alignmask;
  746                         if (ef->shstrtab && shdr[i].sh_name != 0)
  747                                 ef->progtab[pb].name =
  748                                     ef->shstrtab + shdr[i].sh_name;
  749                         else if (shdr[i].sh_type == SHT_PROGBITS)
  750                                 ef->progtab[pb].name = "<<PROGBITS>>";
  751 #ifdef __amd64__
  752                         else if (shdr[i].sh_type == SHT_AMD64_UNWIND)
  753                                 ef->progtab[pb].name = "<<UNWIND>>";
  754 #endif
  755                         else
  756                                 ef->progtab[pb].name = "<<NOBITS>>";
  757                         if (ef->progtab[pb].name != NULL && 
  758                             !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
  759                                 ef->progtab[pb].addr =
  760                                     dpcpu_alloc(shdr[i].sh_size);
  761 #ifdef VIMAGE
  762                         else if (ef->progtab[pb].name != NULL &&
  763                             !strcmp(ef->progtab[pb].name, VNET_SETNAME))
  764                                 ef->progtab[pb].addr =
  765                                     vnet_data_alloc(shdr[i].sh_size);
  766 #endif
  767                         else
  768                                 ef->progtab[pb].addr =
  769                                     (void *)(uintptr_t)mapbase;
  770                         if (ef->progtab[pb].addr == NULL) {
  771                                 error = ENOSPC;
  772                                 goto out;
  773                         }
  774                         ef->progtab[pb].size = shdr[i].sh_size;
  775                         ef->progtab[pb].sec = i;
  776                         if (shdr[i].sh_type == SHT_PROGBITS
  777 #ifdef __amd64__
  778                             || shdr[i].sh_type == SHT_AMD64_UNWIND
  779 #endif
  780                             ) {
  781                                 error = vn_rdwr(UIO_READ, nd.ni_vp,
  782                                     ef->progtab[pb].addr,
  783                                     shdr[i].sh_size, shdr[i].sh_offset,
  784                                     UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
  785                                     NOCRED, &resid, td);
  786                                 if (error)
  787                                         goto out;
  788                                 if (resid != 0){
  789                                         error = EINVAL;
  790                                         goto out;
  791                                 }
  792                                 /* Initialize the per-cpu or vnet area. */
  793                                 if (ef->progtab[pb].addr != (void *)mapbase &&
  794                                     !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
  795                                         dpcpu_copy(ef->progtab[pb].addr,
  796                                             shdr[i].sh_size);
  797 #ifdef VIMAGE
  798                                 else if (ef->progtab[pb].addr !=
  799                                     (void *)mapbase &&
  800                                     !strcmp(ef->progtab[pb].name, VNET_SETNAME))
  801                                         vnet_data_copy(ef->progtab[pb].addr,
  802                                             shdr[i].sh_size);
  803 #endif
  804                         } else
  805                                 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
  806 
  807                         /* Update all symbol values with the offset. */
  808                         for (j = 0; j < ef->ddbsymcnt; j++) {
  809                                 es = &ef->ddbsymtab[j];
  810                                 if (es->st_shndx != i)
  811                                         continue;
  812                                 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
  813                         }
  814                         mapbase += shdr[i].sh_size;
  815                         pb++;
  816                         break;
  817                 case SHT_REL:
  818                         ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
  819                             M_WAITOK);
  820                         ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
  821                         ef->reltab[rl].sec = shdr[i].sh_info;
  822                         error = vn_rdwr(UIO_READ, nd.ni_vp,
  823                             (void *)ef->reltab[rl].rel,
  824                             shdr[i].sh_size, shdr[i].sh_offset,
  825                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
  826                             &resid, td);
  827                         if (error)
  828                                 goto out;
  829                         if (resid != 0){
  830                                 error = EINVAL;
  831                                 goto out;
  832                         }
  833                         rl++;
  834                         break;
  835                 case SHT_RELA:
  836                         ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
  837                             M_WAITOK);
  838                         ef->relatab[ra].nrela =
  839                             shdr[i].sh_size / sizeof(Elf_Rela);
  840                         ef->relatab[ra].sec = shdr[i].sh_info;
  841                         error = vn_rdwr(UIO_READ, nd.ni_vp,
  842                             (void *)ef->relatab[ra].rela,
  843                             shdr[i].sh_size, shdr[i].sh_offset,
  844                             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
  845                             &resid, td);
  846                         if (error)
  847                                 goto out;
  848                         if (resid != 0){
  849                                 error = EINVAL;
  850                                 goto out;
  851                         }
  852                         ra++;
  853                         break;
  854                 }
  855         }
  856         if (pb != ef->nprogtab)
  857                 panic("lost progbits");
  858         if (rl != ef->nreltab)
  859                 panic("lost reltab");
  860         if (ra != ef->nrelatab)
  861                 panic("lost relatab");
  862         if (mapbase != (vm_offset_t)ef->address + mapsize)
  863                 panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
  864                     (u_long)mapbase, ef->address, (u_long)mapsize,
  865                     (u_long)(vm_offset_t)ef->address + mapsize);
  866 
  867         /* Local intra-module relocations */
  868         link_elf_reloc_local(lf);
  869 
  870         /* Pull in dependencies */
  871         VOP_UNLOCK(nd.ni_vp, 0);
  872         error = linker_load_dependencies(lf);
  873         vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
  874         if (error)
  875                 goto out;
  876 
  877         /* External relocations */
  878         error = relocate_file(ef);
  879         if (error)
  880                 goto out;
  881 
  882         /* Notify MD code that a module is being loaded. */
  883         error = elf_cpu_load_file(lf);
  884         if (error)
  885                 goto out;
  886 
  887         *result = lf;
  888 
  889 out:
  890         VOP_UNLOCK(nd.ni_vp, 0);
  891         vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
  892         VFS_UNLOCK_GIANT(vfslocked);
  893         if (error && lf)
  894                 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
  895         if (hdr)
  896                 free(hdr, M_LINKER);
  897 
  898         return error;
  899 }
  900 
  901 static void
  902 link_elf_unload_file(linker_file_t file)
  903 {
  904         elf_file_t ef = (elf_file_t) file;
  905         int i;
  906 
  907         /* Notify MD code that a module is being unloaded. */
  908         elf_cpu_unload_file(file);
  909 
  910         if (ef->progtab) {
  911                 for (i = 0; i < ef->nprogtab; i++) {
  912                         if (ef->progtab[i].size == 0)
  913                                 continue;
  914                         if (ef->progtab[i].name == NULL)
  915                                 continue;
  916                         if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
  917                                 dpcpu_free(ef->progtab[i].addr,
  918                                     ef->progtab[i].size);
  919 #ifdef VIMAGE
  920                         else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
  921                                 vnet_data_free(ef->progtab[i].addr,
  922                                     ef->progtab[i].size);
  923 #endif
  924                 }
  925         }
  926         if (ef->preloaded) {
  927                 if (ef->reltab)
  928                         free(ef->reltab, M_LINKER);
  929                 if (ef->relatab)
  930                         free(ef->relatab, M_LINKER);
  931                 if (ef->progtab)
  932                         free(ef->progtab, M_LINKER);
  933                 if (ef->ctftab)
  934                         free(ef->ctftab, M_LINKER);
  935                 if (ef->ctfoff)
  936                         free(ef->ctfoff, M_LINKER);
  937                 if (ef->typoff)
  938                         free(ef->typoff, M_LINKER);
  939                 if (file->filename != NULL)
  940                         preload_delete_name(file->filename);
  941                 /* XXX reclaim module memory? */
  942                 return;
  943         }
  944 
  945         for (i = 0; i < ef->nreltab; i++)
  946                 if (ef->reltab[i].rel)
  947                         free(ef->reltab[i].rel, M_LINKER);
  948         for (i = 0; i < ef->nrelatab; i++)
  949                 if (ef->relatab[i].rela)
  950                         free(ef->relatab[i].rela, M_LINKER);
  951         if (ef->reltab)
  952                 free(ef->reltab, M_LINKER);
  953         if (ef->relatab)
  954                 free(ef->relatab, M_LINKER);
  955         if (ef->progtab)
  956                 free(ef->progtab, M_LINKER);
  957 
  958         if (ef->object) {
  959                 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
  960                     (vm_offset_t) ef->address +
  961                     (ef->object->size << PAGE_SHIFT));
  962         }
  963         if (ef->e_shdr)
  964                 free(ef->e_shdr, M_LINKER);
  965         if (ef->ddbsymtab)
  966                 free(ef->ddbsymtab, M_LINKER);
  967         if (ef->ddbstrtab)
  968                 free(ef->ddbstrtab, M_LINKER);
  969         if (ef->shstrtab)
  970                 free(ef->shstrtab, M_LINKER);
  971         if (ef->ctftab)
  972                 free(ef->ctftab, M_LINKER);
  973         if (ef->ctfoff)
  974                 free(ef->ctfoff, M_LINKER);
  975         if (ef->typoff)
  976                 free(ef->typoff, M_LINKER);
  977 }
  978 
  979 static const char *
  980 symbol_name(elf_file_t ef, Elf_Size r_info)
  981 {
  982         const Elf_Sym *ref;
  983 
  984         if (ELF_R_SYM(r_info)) {
  985                 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
  986                 return ef->ddbstrtab + ref->st_name;
  987         } else
  988                 return NULL;
  989 }
  990 
  991 static Elf_Addr
  992 findbase(elf_file_t ef, int sec)
  993 {
  994         int i;
  995         Elf_Addr base = 0;
  996 
  997         for (i = 0; i < ef->nprogtab; i++) {
  998                 if (sec == ef->progtab[i].sec) {
  999                         base = (Elf_Addr)ef->progtab[i].addr;
 1000                         break;
 1001                 }
 1002         }
 1003         return base;
 1004 }
 1005 
 1006 static int
 1007 relocate_file(elf_file_t ef)
 1008 {
 1009         const Elf_Rel *rellim;
 1010         const Elf_Rel *rel;
 1011         const Elf_Rela *relalim;
 1012         const Elf_Rela *rela;
 1013         const char *symname;
 1014         const Elf_Sym *sym;
 1015         int i;
 1016         Elf_Size symidx;
 1017         Elf_Addr base;
 1018 
 1019 
 1020         /* Perform relocations without addend if there are any: */
 1021         for (i = 0; i < ef->nreltab; i++) {
 1022                 rel = ef->reltab[i].rel;
 1023                 if (rel == NULL)
 1024                         panic("lost a reltab!");
 1025                 rellim = rel + ef->reltab[i].nrel;
 1026                 base = findbase(ef, ef->reltab[i].sec);
 1027                 if (base == 0)
 1028                         panic("lost base for reltab");
 1029                 for ( ; rel < rellim; rel++) {
 1030                         symidx = ELF_R_SYM(rel->r_info);
 1031                         if (symidx >= ef->ddbsymcnt)
 1032                                 continue;
 1033                         sym = ef->ddbsymtab + symidx;
 1034                         /* Local relocs are already done */
 1035                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
 1036                                 continue;
 1037                         if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
 1038                             elf_obj_lookup)) {
 1039                                 symname = symbol_name(ef, rel->r_info);
 1040                                 printf("link_elf_obj: symbol %s undefined\n",
 1041                                     symname);
 1042                                 return ENOENT;
 1043                         }
 1044                 }
 1045         }
 1046 
 1047         /* Perform relocations with addend if there are any: */
 1048         for (i = 0; i < ef->nrelatab; i++) {
 1049                 rela = ef->relatab[i].rela;
 1050                 if (rela == NULL)
 1051                         panic("lost a relatab!");
 1052                 relalim = rela + ef->relatab[i].nrela;
 1053                 base = findbase(ef, ef->relatab[i].sec);
 1054                 if (base == 0)
 1055                         panic("lost base for relatab");
 1056                 for ( ; rela < relalim; rela++) {
 1057                         symidx = ELF_R_SYM(rela->r_info);
 1058                         if (symidx >= ef->ddbsymcnt)
 1059                                 continue;
 1060                         sym = ef->ddbsymtab + symidx;
 1061                         /* Local relocs are already done */
 1062                         if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
 1063                                 continue;
 1064                         if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
 1065                             elf_obj_lookup)) {
 1066                                 symname = symbol_name(ef, rela->r_info);
 1067                                 printf("link_elf_obj: symbol %s undefined\n",
 1068                                     symname);
 1069                                 return ENOENT;
 1070                         }
 1071                 }
 1072         }
 1073 
 1074         return 0;
 1075 }
 1076 
 1077 static int
 1078 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
 1079 {
 1080         elf_file_t ef = (elf_file_t) lf;
 1081         const Elf_Sym *symp;
 1082         const char *strp;
 1083         int i;
 1084 
 1085         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
 1086                 strp = ef->ddbstrtab + symp->st_name;
 1087                 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
 1088                         *sym = (c_linker_sym_t) symp;
 1089                         return 0;
 1090                 }
 1091         }
 1092         return ENOENT;
 1093 }
 1094 
 1095 static int
 1096 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
 1097     linker_symval_t *symval)
 1098 {
 1099         elf_file_t ef = (elf_file_t) lf;
 1100         const Elf_Sym *es = (const Elf_Sym*) sym;
 1101 
 1102         if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
 1103                 symval->name = ef->ddbstrtab + es->st_name;
 1104                 symval->value = (caddr_t)es->st_value;
 1105                 symval->size = es->st_size;
 1106                 return 0;
 1107         }
 1108         return ENOENT;
 1109 }
 1110 
 1111 static int
 1112 link_elf_search_symbol(linker_file_t lf, caddr_t value,
 1113     c_linker_sym_t *sym, long *diffp)
 1114 {
 1115         elf_file_t ef = (elf_file_t) lf;
 1116         u_long off = (uintptr_t) (void *) value;
 1117         u_long diff = off;
 1118         u_long st_value;
 1119         const Elf_Sym *es;
 1120         const Elf_Sym *best = 0;
 1121         int i;
 1122 
 1123         for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
 1124                 if (es->st_name == 0)
 1125                         continue;
 1126                 st_value = es->st_value;
 1127                 if (off >= st_value) {
 1128                         if (off - st_value < diff) {
 1129                                 diff = off - st_value;
 1130                                 best = es;
 1131                                 if (diff == 0)
 1132                                         break;
 1133                         } else if (off - st_value == diff) {
 1134                                 best = es;
 1135                         }
 1136                 }
 1137         }
 1138         if (best == 0)
 1139                 *diffp = off;
 1140         else
 1141                 *diffp = diff;
 1142         *sym = (c_linker_sym_t) best;
 1143 
 1144         return 0;
 1145 }
 1146 
 1147 /*
 1148  * Look up a linker set on an ELF system.
 1149  */
 1150 static int
 1151 link_elf_lookup_set(linker_file_t lf, const char *name,
 1152     void ***startp, void ***stopp, int *countp)
 1153 {
 1154         elf_file_t ef = (elf_file_t)lf;
 1155         void **start, **stop;
 1156         int i, count;
 1157 
 1158         /* Relative to section number */
 1159         for (i = 0; i < ef->nprogtab; i++) {
 1160                 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
 1161                     strcmp(ef->progtab[i].name + 4, name) == 0) {
 1162                         start  = (void **)ef->progtab[i].addr;
 1163                         stop = (void **)((char *)ef->progtab[i].addr +
 1164                             ef->progtab[i].size);
 1165                         count = stop - start;
 1166                         if (startp)
 1167                                 *startp = start;
 1168                         if (stopp)
 1169                                 *stopp = stop;
 1170                         if (countp)
 1171                                 *countp = count;
 1172                         return (0);
 1173                 }
 1174         }
 1175         return (ESRCH);
 1176 }
 1177 
 1178 static int
 1179 link_elf_each_function_name(linker_file_t file,
 1180     int (*callback)(const char *, void *), void *opaque)
 1181 {
 1182         elf_file_t ef = (elf_file_t)file;
 1183         const Elf_Sym *symp;
 1184         int i, error;
 1185         
 1186         /* Exhaustive search */
 1187         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
 1188                 if (symp->st_value != 0 &&
 1189                     ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
 1190                         error = callback(ef->ddbstrtab + symp->st_name, opaque);
 1191                         if (error)
 1192                                 return (error);
 1193                 }
 1194         }
 1195         return (0);
 1196 }
 1197 
 1198 static int
 1199 link_elf_each_function_nameval(linker_file_t file,
 1200     linker_function_nameval_callback_t callback, void *opaque)
 1201 {
 1202         linker_symval_t symval;
 1203         elf_file_t ef = (elf_file_t)file;
 1204         const Elf_Sym* symp;
 1205         int i, error;
 1206 
 1207         /* Exhaustive search */
 1208         for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
 1209                 if (symp->st_value != 0 &&
 1210                     ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
 1211                         error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
 1212                         if (error)
 1213                                 return (error);
 1214                         error = callback(file, i, &symval, opaque);
 1215                         if (error)
 1216                                 return (error);
 1217                 }
 1218         }
 1219         return (0);
 1220 }
 1221 
 1222 /*
 1223  * Symbol lookup function that can be used when the symbol index is known (ie
 1224  * in relocations). It uses the symbol index instead of doing a fully fledged
 1225  * hash table based lookup when such is valid. For example for local symbols.
 1226  * This is not only more efficient, it's also more correct. It's not always
 1227  * the case that the symbol can be found through the hash table.
 1228  */
 1229 static Elf_Addr
 1230 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps)
 1231 {
 1232         elf_file_t ef = (elf_file_t)lf;
 1233         const Elf_Sym *sym;
 1234         const char *symbol;
 1235         Elf_Addr ret;
 1236 
 1237         /* Don't even try to lookup the symbol if the index is bogus. */
 1238         if (symidx >= ef->ddbsymcnt)
 1239                 return (0);
 1240 
 1241         sym = ef->ddbsymtab + symidx;
 1242 
 1243         /* Quick answer if there is a definition included. */
 1244         if (sym->st_shndx != SHN_UNDEF)
 1245                 return (sym->st_value);
 1246 
 1247         /* If we get here, then it is undefined and needs a lookup. */
 1248         switch (ELF_ST_BIND(sym->st_info)) {
 1249         case STB_LOCAL:
 1250                 /* Local, but undefined? huh? */
 1251                 return (0);
 1252 
 1253         case STB_GLOBAL:
 1254                 /* Relative to Data or Function name */
 1255                 symbol = ef->ddbstrtab + sym->st_name;
 1256 
 1257                 /* Force a lookup failure if the symbol name is bogus. */
 1258                 if (*symbol == 0)
 1259                         return (0);
 1260                 ret = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
 1261                 return ret;
 1262 
 1263         case STB_WEAK:
 1264                 printf("link_elf_obj: Weak symbols not supported\n");
 1265                 return (0);
 1266 
 1267         default:
 1268                 return (0);
 1269         }
 1270 }
 1271 
 1272 static void
 1273 link_elf_fix_link_set(elf_file_t ef)
 1274 {
 1275         static const char startn[] = "__start_";
 1276         static const char stopn[] = "__stop_";
 1277         Elf_Sym *sym;
 1278         const char *sym_name, *linkset_name;
 1279         Elf_Addr startp, stopp;
 1280         Elf_Size symidx;
 1281         int start, i;
 1282 
 1283         startp = stopp = 0;
 1284         for (symidx = 1 /* zero entry is special */;
 1285                 symidx < ef->ddbsymcnt; symidx++) {
 1286                 sym = ef->ddbsymtab + symidx;
 1287                 if (sym->st_shndx != SHN_UNDEF)
 1288                         continue;
 1289 
 1290                 sym_name = ef->ddbstrtab + sym->st_name;
 1291                 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
 1292                         start = 1;
 1293                         linkset_name = sym_name + sizeof(startn) - 1;
 1294                 }
 1295                 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
 1296                         start = 0;
 1297                         linkset_name = sym_name + sizeof(stopn) - 1;
 1298                 }
 1299                 else
 1300                         continue;
 1301 
 1302                 for (i = 0; i < ef->nprogtab; i++) {
 1303                         if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
 1304                                 startp = (Elf_Addr)ef->progtab[i].addr;
 1305                                 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
 1306                                 break;
 1307                         }
 1308                 }
 1309                 if (i == ef->nprogtab)
 1310                         continue;
 1311 
 1312                 sym->st_value = start ? startp : stopp;
 1313                 sym->st_shndx = i;
 1314         }
 1315 }
 1316 
 1317 static void
 1318 link_elf_reloc_local(linker_file_t lf)
 1319 {
 1320         elf_file_t ef = (elf_file_t)lf;
 1321         const Elf_Rel *rellim;
 1322         const Elf_Rel *rel;
 1323         const Elf_Rela *relalim;
 1324         const Elf_Rela *rela;
 1325         const Elf_Sym *sym;
 1326         Elf_Addr base;
 1327         int i;
 1328         Elf_Size symidx;
 1329 
 1330         link_elf_fix_link_set(ef);
 1331 
 1332         /* Perform relocations without addend if there are any: */
 1333         for (i = 0; i < ef->nreltab; i++) {
 1334                 rel = ef->reltab[i].rel;
 1335                 if (rel == NULL)
 1336                         panic("lost a reltab!");
 1337                 rellim = rel + ef->reltab[i].nrel;
 1338                 base = findbase(ef, ef->reltab[i].sec);
 1339                 if (base == 0)
 1340                         panic("lost base for reltab");
 1341                 for ( ; rel < rellim; rel++) {
 1342                         symidx = ELF_R_SYM(rel->r_info);
 1343                         if (symidx >= ef->ddbsymcnt)
 1344                                 continue;
 1345                         sym = ef->ddbsymtab + symidx;
 1346                         /* Only do local relocs */
 1347                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
 1348                                 continue;
 1349                         elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
 1350                             elf_obj_lookup);
 1351                 }
 1352         }
 1353 
 1354         /* Perform relocations with addend if there are any: */
 1355         for (i = 0; i < ef->nrelatab; i++) {
 1356                 rela = ef->relatab[i].rela;
 1357                 if (rela == NULL)
 1358                         panic("lost a relatab!");
 1359                 relalim = rela + ef->relatab[i].nrela;
 1360                 base = findbase(ef, ef->relatab[i].sec);
 1361                 if (base == 0)
 1362                         panic("lost base for relatab");
 1363                 for ( ; rela < relalim; rela++) {
 1364                         symidx = ELF_R_SYM(rela->r_info);
 1365                         if (symidx >= ef->ddbsymcnt)
 1366                                 continue;
 1367                         sym = ef->ddbsymtab + symidx;
 1368                         /* Only do local relocs */
 1369                         if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
 1370                                 continue;
 1371                         elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
 1372                             elf_obj_lookup);
 1373                 }
 1374         }
 1375 }
 1376 
 1377 static long
 1378 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
 1379 {
 1380     elf_file_t ef = (elf_file_t)lf;
 1381     
 1382     *symtab = ef->ddbsymtab;
 1383     
 1384     if (*symtab == NULL)
 1385         return (0);
 1386 
 1387     return (ef->ddbsymcnt);
 1388 }
 1389     
 1390 static long
 1391 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
 1392 {
 1393     elf_file_t ef = (elf_file_t)lf;
 1394 
 1395     *strtab = ef->ddbstrtab;
 1396 
 1397     if (*strtab == NULL)
 1398         return (0);
 1399 
 1400     return (ef->ddbstrcnt);
 1401 }

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