sys/platform/pc64/amd64/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  * $FreeBSD: src/sys/i386/i386/elf_machdep.c,v 1.8 1999/12/21 11:14:02 eivind Exp $
  26  * $DragonFly: src/sys/platform/pc64/amd64/elf_machdep.c,v 1.2 2007/09/24 03:24:45 yanyh Exp $
  27  */
  28
  29 #include <sys/param.h>
  30 #include <sys/systm.h>
  31 #include <sys/linker.h>
  32 #include <machine/elf.h>
  33
  34 /* Process one elf relocation with addend. */
  35 static int
  36 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
  37     int type, int local, elf_lookup_fn lookup)
  38 {
  39         Elf64_Addr *where, val;
  40         Elf32_Addr *where32, val32;
  41         Elf_Addr addr;
  42         Elf_Addr addend;
  43         Elf_Size rtype, symidx;
  44         const Elf_Rel *rel;
  45         const Elf_Rela *rela;
  46
  47         switch (type) {
  48         case ELF_RELOC_REL:
  49                 rel = (const Elf_Rel *)data;
  50                 where = (Elf_Addr *) (relocbase + rel->r_offset);
  51                 rtype = ELF_R_TYPE(rel->r_info);
  52                 symidx = ELF_R_SYM(rel->r_info);
  53                 /* Addend is 32 bit on 32 bit relocs */
  54                 switch (rtype) {
  55                 case R_X86_64_PC32:
  56                 case R_X86_64_32:
  57                 case R_X86_64_32S:
  58                         addend = *(Elf32_Addr *)where;
  59                         break;
  60                 default:
  61                         addend = *where;
  62                         break;
  63                 }
  64                 break;
  65         case ELF_RELOC_RELA:
  66                 rela = (const Elf_Rela *)data;
  67                 where = (Elf_Addr *) (relocbase + rela->r_offset);
  68                 addend = rela->r_addend;
  69                 rtype = ELF_R_TYPE(rela->r_info);
  70                 symidx = ELF_R_SYM(rela->r_info);
  71                 break;
  72         default:
  73                 panic("unknown reloc type %d\n", type);
  74         }
  75
  76         switch (rtype) {
  77
  78                 case R_X86_64_NONE:     /* none */
  79                         break;
  80
  81                 case R_X86_64_64:               /* S + A */
  82                         if (lookup(lf, symidx, 1, &addr))
  83                                 return -1;
  84                         val = addr + addend;
  85                         if (*where != val)
  86                                 *where = val;
  87                         break;
  88
  89                 case R_X86_64_PC32:     /* S + A - P */
  90                         if (lookup(lf, symidx, 1, &addr))
  91                                 return -1;
  92                         where32 = (Elf32_Addr *)where;
  93                         val32 = (Elf32_Addr)(addr + addend - (Elf_Addr)where);
  94                         if (*where32 != val32)
  95                                 *where32 = val32;
  96                         break;
  97
  98                 case R_X86_64_32:       /* S + A zero extend */
  99                 case R_X86_64_32S:      /* S + A sign extend */
 100                         if (lookup(lf, symidx, 1, &addr))
 101                                 return -1;
 102                         val32 = (Elf32_Addr)(addr + addend);
 103                         where32 = (Elf32_Addr *)where;
 104                         if (*where32 != val32)
 105                                 *where32 = val32;
 106                         break;
 107
 108                 case R_X86_64_COPY:     /* none */
 109                         /*
 110                          * There shouldn't be copy relocations in kernel
 111                          * objects.
 112                          */
 113                         kprintf("kldload: unexpected R_COPY relocation\n");
 114                         return -1;
 115                         break;
 116
 117                 case R_X86_64_GLOB_DAT: /* S */
 118                 case R_X86_64_JMP_SLOT: /* XXX need addend + offset */
 119                         if (lookup(lf, symidx, 1, &addr))
 120                                 return -1;
 121                         if (*where != addr)
 122                                 *where = addr;
 123                         break;
 124
 125                 case R_X86_64_RELATIVE: /* B + A */
 126                         addr = relocbase + addend;
 127                         val = addr;
 128                         if (*where != val)
 129                                 *where = val;
 130                         break;
 131
 132                 default:
 133                         kprintf("kldload: unexpected relocation type %ld\n",
 134                                rtype);
 135                         return -1;
 136         }
 137         return(0);
 138 }
 139
 140 int
 141 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
 142     elf_lookup_fn lookup)
 143 {
 144
 145         return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup));
 146 }
 147
 148 int
 149 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
 150     int type, elf_lookup_fn lookup)
 151 {
 152
 153         return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup));
 154 }