1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2003 Jake Burkholder. 5 * Copyright 1996-1998 John D. Polstra. 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/endian.h> 31 32 #include <err.h> 33 #include <errno.h> 34 #include <gelf.h> 35 36 #include "kldelf.h" 37 38 /* 39 * Apply relocations to the values obtained from the file. `relbase' is the 40 * target relocation address of the section, and `dataoff/len' is the region 41 * that is to be relocated, and has been copied to *dest 42 */ 43 static int 44 ef_amd64_reloc(struct elf_file *ef, const void *reldata, Elf_Type reltype, 45 GElf_Addr relbase, GElf_Addr dataoff, size_t len, void *dest) 46 { 47 char *where; 48 GElf_Addr addr, addend; 49 GElf_Size rtype, symidx; 50 const GElf_Rel *rel; 51 const GElf_Rela *rela; 52 53 switch (reltype) { 54 case ELF_T_REL: 55 rel = (const GElf_Rel *)reldata; 56 where = (char *)dest + (relbase + rel->r_offset - dataoff); 57 addend = 0; 58 rtype = GELF_R_TYPE(rel->r_info); 59 symidx = GELF_R_SYM(rel->r_info); 60 break; 61 case ELF_T_RELA: 62 rela = (const GElf_Rela *)reldata; 63 where = (char *)dest + (relbase + rela->r_offset - dataoff); 64 addend = rela->r_addend; 65 rtype = GELF_R_TYPE(rela->r_info); 66 symidx = GELF_R_SYM(rela->r_info); 67 break; 68 default: 69 return (EINVAL); 70 } 71 72 if (where < (char *)dest || where >= (char *)dest + len) 73 return (0); 74 75 if (reltype == ELF_T_REL) { 76 /* Addend is 32 bit on 32 bit relocs */ 77 switch (rtype) { 78 case R_X86_64_PC32: 79 case R_X86_64_32S: 80 addend = le32dec(where); 81 break; 82 default: 83 addend = le64dec(where); 84 break; 85 } 86 } 87 88 switch (rtype) { 89 case R_X86_64_NONE: /* none */ 90 break; 91 case R_X86_64_64: /* S + A */ 92 addr = EF_SYMADDR(ef, symidx) + addend; 93 le64enc(where, addr); 94 break; 95 case R_X86_64_32S: /* S + A sign extend */ 96 addr = EF_SYMADDR(ef, symidx) + addend; 97 le32enc(where, addr); 98 break; 99 case R_X86_64_GLOB_DAT: /* S */ 100 addr = EF_SYMADDR(ef, symidx); 101 le64enc(where, addr); 102 break; 103 case R_X86_64_RELATIVE: /* B + A */ 104 addr = relbase + addend; 105 le64enc(where, addr); 106 break; 107 default: 108 warnx("unhandled relocation type %d", (int)rtype); 109 } 110 return (0); 111 } 112 113 ELF_RELOC(ELFCLASS64, ELFDATA2LSB, EM_X86_64, ef_amd64_reloc); 114