sys/i386/i386/elf_machdep.c

   1 /*-
   2  * Copyright 1996-1998 John D. Polstra.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include <sys/cdefs.h>
  27 __FBSDID("$FreeBSD$");
  28
  29 #include <sys/param.h>
  30 #include <sys/kernel.h>
  31 #include <sys/systm.h>
  32 #include <sys/exec.h>
  33 #include <sys/imgact.h>
  34 #include <sys/linker.h>
  35 #include <sys/sysent.h>
  36 #include <sys/imgact_elf.h>
  37 #include <sys/syscall.h>
  38 #include <sys/signalvar.h>
  39 #include <sys/vnode.h>
  40
  41 #include <vm/vm.h>
  42 #include <vm/pmap.h>
  43 #include <vm/vm_param.h>
  44
  45 #include <machine/elf.h>
  46 #include <machine/md_var.h>
  47
  48 struct sysentvec elf32_freebsd_sysvec = {
  49         SYS_MAXSYSCALL,
  50         sysent,
  51         0,
  52         0,
  53         NULL,
  54         0,
  55         NULL,
  56         NULL,
  57         __elfN(freebsd_fixup),
  58         sendsig,
  59         sigcode,
  60         &szsigcode,
  61         NULL,
  62         "FreeBSD ELF32",
  63         __elfN(coredump),
  64         NULL,
  65         MINSIGSTKSZ,
  66         PAGE_SIZE,
  67         VM_MIN_ADDRESS,
  68         VM_MAXUSER_ADDRESS,
  69         USRSTACK,
  70         PS_STRINGS,
  71         VM_PROT_ALL,
  72         exec_copyout_strings,
  73         exec_setregs,
  74         NULL
  75 };
  76
  77 static Elf32_Brandinfo freebsd_brand_info = {
  78                                                 ELFOSABI_FREEBSD,
  79                                                 EM_386,
  80                                                 "FreeBSD",
  81                                                 NULL,
  82                                                 "/libexec/ld-elf.so.1",
  83                                                 &elf32_freebsd_sysvec,
  84                                                 NULL,
  85                                                 0,
  86                                           };
  87
  88 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_ANY,
  89         (sysinit_cfunc_t) elf32_insert_brand_entry,
  90         &freebsd_brand_info);
  91
  92 static Elf32_Brandinfo freebsd_brand_oinfo = {
  93                                                 ELFOSABI_FREEBSD,
  94                                                 EM_386,
  95                                                 "FreeBSD",
  96                                                 NULL,
  97                                                 "/usr/libexec/ld-elf.so.1",
  98                                                 &elf32_freebsd_sysvec,
  99                                                 NULL,
 100                                                 0,
 101                                           };
 102
 103 SYSINIT(oelf32, SI_SUB_EXEC, SI_ORDER_ANY,
 104         (sysinit_cfunc_t) elf32_insert_brand_entry,
 105         &freebsd_brand_oinfo);
 106
 107
 108 void
 109 elf32_dump_thread(struct thread *td __unused, void *dst __unused,
 110     size_t *off __unused)
 111 {
 112 }
 113
 114
 115 /* Process one elf relocation with addend. */
 116 static int
 117 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
 118     int type, int local, elf_lookup_fn lookup)
 119 {
 120         Elf_Addr *where;
 121         Elf_Addr addr;
 122         Elf_Addr addend;
 123         Elf_Word rtype, symidx;
 124         const Elf_Rel *rel;
 125         const Elf_Rela *rela;
 126
 127         switch (type) {
 128         case ELF_RELOC_REL:
 129                 rel = (const Elf_Rel *)data;
 130                 where = (Elf_Addr *) (relocbase + rel->r_offset);
 131                 addend = *where;
 132                 rtype = ELF_R_TYPE(rel->r_info);
 133                 symidx = ELF_R_SYM(rel->r_info);
 134                 break;
 135         case ELF_RELOC_RELA:
 136                 rela = (const Elf_Rela *)data;
 137                 where = (Elf_Addr *) (relocbase + rela->r_offset);
 138                 addend = rela->r_addend;
 139                 rtype = ELF_R_TYPE(rela->r_info);
 140                 symidx = ELF_R_SYM(rela->r_info);
 141                 break;
 142         default:
 143                 panic("unknown reloc type %d\n", type);
 144         }
 145
 146         if (local) {
 147                 if (rtype == R_386_RELATIVE) {  /* A + B */
 148                         addr = relocbase + addend;
 149                         if (*where != addr)
 150                                 *where = addr;
 151                 }
 152                 return (0);
 153         }
 154
 155         switch (rtype) {
 156
 157                 case R_386_NONE:        /* none */
 158                         break;
 159
 160                 case R_386_32:          /* S + A */
 161                         addr = lookup(lf, symidx, 1);
 162                         if (addr == 0)
 163                                 return -1;
 164                         addr += addend;
 165                         if (*where != addr)
 166                                 *where = addr;
 167                         break;
 168
 169                 case R_386_PC32:        /* S + A - P */
 170                         addr = lookup(lf, symidx, 1);
 171                         if (addr == 0)
 172                                 return -1;
 173                         addr += addend - (Elf_Addr)where;
 174                         if (*where != addr)
 175                                 *where = addr;
 176                         break;
 177
 178                 case R_386_COPY:        /* none */
 179                         /*
 180                          * There shouldn't be copy relocations in kernel
 181                          * objects.
 182                          */
 183                         printf("kldload: unexpected R_COPY relocation\n");
 184                         return -1;
 185                         break;
 186
 187                 case R_386_GLOB_DAT:    /* S */
 188                         addr = lookup(lf, symidx, 1);
 189                         if (addr == 0)
 190                                 return -1;
 191                         if (*where != addr)
 192                                 *where = addr;
 193                         break;
 194
 195                 case R_386_RELATIVE:
 196                         break;
 197
 198                 default:
 199                         printf("kldload: unexpected relocation type %d\n",
 200                                rtype);
 201                         return -1;
 202         }
 203         return(0);
 204 }
 205
 206 int
 207 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
 208     elf_lookup_fn lookup)
 209 {
 210
 211         return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup));
 212 }
 213
 214 int
 215 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
 216     int type, elf_lookup_fn lookup)
 217 {
 218
 219         return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup));
 220 }
 221
 222 int
 223 elf_cpu_load_file(linker_file_t lf __unused)
 224 {
 225
 226         return (0);
 227 }
 228
 229 int
 230 elf_cpu_unload_file(linker_file_t lf __unused)
 231 {
 232
 233         return (0);
 234 }