1 /*- 2 * Copyright (c) 2003 Jake Burkholder. 3 * Copyright 1996-1998 John D. Polstra. 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 * $FreeBSD$ 28 */ 29 30 #include <sys/types.h> 31 #include <machine/elf.h> 32 33 #include <err.h> 34 #include <errno.h> 35 #include <string.h> 36 37 #include "ef.h" 38 39 /* 40 * Apply relocations to the values we got from the file. `relbase' is the 41 * target relocation address of the section, and `dataoff' is the target 42 * relocation address of the data in `dest'. 43 */ 44 int 45 ef_reloc(struct elf_file *ef, const void *reldata, int reltype, Elf_Off relbase, 46 Elf_Off dataoff, size_t len, void *dest) 47 { 48 Elf64_Addr *where, val; 49 Elf32_Addr *where32, val32; 50 Elf_Addr addend, addr; 51 Elf_Size rtype, symidx; 52 const Elf_Rel *rel; 53 const Elf_Rela *rela; 54 55 switch (reltype) { 56 case EF_RELOC_REL: 57 rel = (const Elf_Rel *)reldata; 58 where = (Elf_Addr *)(dest + relbase + rel->r_offset - dataoff); 59 addend = 0; 60 rtype = ELF_R_TYPE(rel->r_info); 61 symidx = ELF_R_SYM(rel->r_info); 62 break; 63 case EF_RELOC_RELA: 64 rela = (const Elf_Rela *)reldata; 65 where = (Elf_Addr *)(dest + relbase + rela->r_offset - dataoff); 66 addend = rela->r_addend; 67 rtype = ELF_R_TYPE(rela->r_info); 68 symidx = ELF_R_SYM(rela->r_info); 69 break; 70 default: 71 return (EINVAL); 72 } 73 74 if ((char *)where < (char *)dest || (char *)where >= (char *)dest + len) 75 return (0); 76 77 if (reltype == EF_RELOC_REL) { 78 /* Addend is 32 bit on 32 bit relocs */ 79 switch (rtype) { 80 case R_X86_64_PC32: 81 case R_X86_64_32S: 82 addend = *(Elf32_Addr *)where; 83 break; 84 default: 85 addend = *where; 86 break; 87 } 88 } 89 90 switch (rtype) { 91 case R_X86_64_NONE: /* none */ 92 break; 93 case R_X86_64_64: /* S + A */ 94 addr = EF_SYMADDR(ef, symidx); 95 val = addr + addend; 96 *where = val; 97 break; 98 case R_X86_64_32S: /* S + A sign extend */ 99 addr = EF_SYMADDR(ef, symidx); 100 val32 = (Elf32_Addr)(addr + addend); 101 where32 = (Elf32_Addr *)where; 102 *where32 = val32; 103 break; 104 case R_X86_64_GLOB_DAT: /* S */ 105 addr = EF_SYMADDR(ef, symidx); 106 *where = addr; 107 break; 108 case R_X86_64_RELATIVE: /* B + A */ 109 addr = (Elf_Addr)addend + relbase; 110 val = addr; 111 *where = val; 112 break; 113 default: 114 warnx("unhandled relocation type %d", (int)rtype); 115 } 116 return (0); 117 } 118