stand/common/reloc_elf.c

   1 /*-
   2  * Copyright (c) 2003 Jake Burkholder.
   3  * Copyright 1996-1998 John D. Polstra.
   4  * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
   5  * Copyright (c) 1998 Peter Wemm <peter@freebsd.org>
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #include <sys/types.h>
  31 #include <machine/elf.h>
  32
  33 #include <stand.h>
  34
  35 #include <sys/link_elf.h>
  36
  37 #include "bootstrap.h"
  38
  39 #define COPYOUT(s,d,l)  archsw.arch_copyout((vm_offset_t)(s), d, l)
  40
  41 /*
  42  * Apply a single intra-module relocation to the data. `relbase' is the
  43  * target relocation base for the section (i.e. it corresponds to where
  44  * r_offset == 0). `dataaddr' is the relocated address corresponding to
  45  * the start of the data, and `len' is the number of bytes.
  46  */
  47 int
  48 __elfN(reloc)(struct elf_file *ef, symaddr_fn *symaddr, const void *reldata,
  49     int reltype, Elf_Addr relbase, Elf_Addr dataaddr, void *data, size_t len)
  50 {
  51 #if (defined(__aarch64__) || defined(__amd64__) || defined(__i386__)) && \
  52     __ELF_WORD_SIZE == 64
  53         Elf64_Addr *where, val;
  54         Elf_Addr addend, addr;
  55         Elf_Size rtype;
  56 #if defined(__amd64__) || defined(__i386__)
  57         Elf_Size symidx;
  58 #endif
  59         const Elf_Rel *rel;
  60         const Elf_Rela *rela;
  61
  62         switch (reltype) {
  63         case ELF_RELOC_REL:
  64                 rel = (const Elf_Rel *)reldata;
  65                 where = (Elf_Addr *)((char *)data + relbase + rel->r_offset -
  66                     dataaddr);
  67                 addend = 0;
  68                 rtype = ELF_R_TYPE(rel->r_info);
  69 #if defined(__amd64__) || defined(__i386__)
  70                 symidx = ELF_R_SYM(rel->r_info);
  71 #endif
  72                 addend = 0;
  73                 break;
  74         case ELF_RELOC_RELA:
  75                 rela = (const Elf_Rela *)reldata;
  76                 where = (Elf_Addr *)((char *)data + relbase + rela->r_offset -
  77                     dataaddr);
  78                 addend = rela->r_addend;
  79                 rtype = ELF_R_TYPE(rela->r_info);
  80 #if defined(__amd64__) || defined(__i386__)
  81                 symidx = ELF_R_SYM(rela->r_info);
  82 #endif
  83                 break;
  84         default:
  85                 return (EINVAL);
  86         }
  87
  88         if ((char *)where < (char *)data || (char *)where >= (char *)data + len)
  89                 return (0);
  90
  91         if (reltype == ELF_RELOC_REL)
  92                 addend = *where;
  93
  94 #if defined(__aarch64__)
  95 #define RELOC_RELATIVE          R_AARCH64_RELATIVE
  96 #define RELOC_IRELATIVE         R_AARCH64_IRELATIVE
  97 #elif defined(__amd64__) || defined(__i386__)
  98 /* XXX, definitions not available on i386. */
  99 #define R_X86_64_64             1
 100 #define R_X86_64_RELATIVE       8
 101 #define R_X86_64_IRELATIVE      37
 102
 103 #define RELOC_RELATIVE          R_X86_64_RELATIVE
 104 #define RELOC_IRELATIVE         R_X86_64_IRELATIVE
 105 #endif
 106
 107         switch (rtype) {
 108         case RELOC_RELATIVE:
 109                 addr = (Elf_Addr)addend + relbase;
 110                 val = addr;
 111                 memcpy(where, &val, sizeof(val));
 112                 break;
 113         case RELOC_IRELATIVE:
 114                 /* leave it to kernel */
 115                 break;
 116 #if defined(__amd64__) || defined(__i386__)
 117         case R_X86_64_64:               /* S + A */
 118                 addr = symaddr(ef, symidx);
 119                 if (addr == 0)
 120                         return (ESRCH);
 121                 val = addr + addend;
 122                 *where = val;
 123                 break;
 124 #endif
 125         default:
 126                 printf("\nunhandled relocation type %u\n", (u_int)rtype);
 127                 return (EFTYPE);
 128         }
 129
 130         return (0);
 131 #elif defined(__i386__) && __ELF_WORD_SIZE == 32
 132         Elf_Addr addend, addr, *where, val;
 133         Elf_Size rtype, symidx;
 134         const Elf_Rel *rel;
 135         const Elf_Rela *rela;
 136
 137         switch (reltype) {
 138         case ELF_RELOC_REL:
 139                 rel = (const Elf_Rel *)reldata;
 140                 where = (Elf_Addr *)((char *)data + relbase + rel->r_offset -
 141                     dataaddr);
 142                 addend = 0;
 143                 rtype = ELF_R_TYPE(rel->r_info);
 144                 symidx = ELF_R_SYM(rel->r_info);
 145                 addend = 0;
 146                 break;
 147         case ELF_RELOC_RELA:
 148                 rela = (const Elf_Rela *)reldata;
 149                 where = (Elf_Addr *)((char *)data + relbase + rela->r_offset -
 150                     dataaddr);
 151                 addend = rela->r_addend;
 152                 rtype = ELF_R_TYPE(rela->r_info);
 153                 symidx = ELF_R_SYM(rela->r_info);
 154                 break;
 155         default:
 156                 return (EINVAL);
 157         }
 158
 159         if ((char *)where < (char *)data || (char *)where >= (char *)data + len)
 160                 return (0);
 161
 162         if (reltype == ELF_RELOC_REL)
 163                 addend = *where;
 164
 165 /* XXX, definitions not available on amd64. */
 166 #define R_386_32        1       /* Add symbol value. */
 167 #define R_386_GLOB_DAT  6       /* Set GOT entry to data address. */
 168 #define R_386_RELATIVE  8       /* Add load address of shared object. */
 169 #define R_386_IRELATIVE 42
 170
 171         switch (rtype) {
 172         case R_386_RELATIVE:
 173                 addr = addend + relbase;
 174                 *where = addr;
 175                 break;
 176         case R_386_32:          /* S + A */
 177                 addr = symaddr(ef, symidx);
 178                 if (addr == 0)
 179                         return (ESRCH);
 180                 val = addr + addend;
 181                 *where = val;
 182                 break;
 183         case R_386_IRELATIVE:
 184                 /* leave it to kernel */
 185                 break;
 186         default:
 187                 printf("\nunhandled relocation type %u\n", (u_int)rtype);
 188                 return (EFTYPE);
 189         }
 190
 191         return (0);
 192 #elif defined(__powerpc__) || defined(__riscv)
 193         Elf_Size w;
 194         const Elf_Rela *rela;
 195
 196         switch (reltype) {
 197         case ELF_RELOC_RELA:
 198                 rela = reldata;
 199                 if (relbase + rela->r_offset >= dataaddr &&
 200                     relbase + rela->r_offset < dataaddr + len) {
 201                         switch (ELF_R_TYPE(rela->r_info)) {
 202 #if defined(__powerpc__)
 203                         case R_PPC_RELATIVE:
 204 #elif defined(__riscv)
 205                         case R_RISCV_RELATIVE:
 206 #endif
 207                                 w = relbase + rela->r_addend;
 208                                 bcopy(&w, (u_char *)data + (relbase +
 209                                       rela->r_offset - dataaddr), sizeof(w));
 210                                 break;
 211                         default:
 212                                 printf("\nunhandled relocation type %u\n",
 213                                        (u_int)ELF_R_TYPE(rela->r_info));
 214                                 return (EFTYPE);
 215                         }
 216                 }
 217                 break;
 218         }
 219
 220         return (0);
 221 #else
 222         return (EOPNOTSUPP);
 223 #endif
 224 }