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 * $FreeBSD$ 30 */ 31 32 #include <sys/types.h> 33 #include <machine/elf.h> 34 35 #include <err.h> 36 #include <errno.h> 37 38 #include "ef.h" 39 40 /* 41 * Apply relocations to the values we got from the file. `relbase' is the 42 * target relocation address of the section, and `dataoff' is the target 43 * relocation address of the data in `dest'. 44 */ 45 int 46 ef_reloc(struct elf_file *ef, const void *reldata, int reltype, Elf_Off relbase, 47 Elf_Off dataoff, size_t len, void *_dest) 48 { 49 Elf_Addr *where, addr, addend; 50 Elf_Size rtype, symidx; 51 const Elf_Rel *rel; 52 const Elf_Rela *rela; 53 char *dest = _dest; 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 = *where; 79 80 switch (rtype) { 81 case R_386_RELATIVE: /* A + B */ 82 addr = (Elf_Addr)addend + relbase; 83 *where = addr; 84 break; 85 case R_386_32: /* S + A - P */ 86 addr = EF_SYMADDR(ef, symidx); 87 addr += addend; 88 *where = addr; 89 break; 90 case R_386_GLOB_DAT: /* S */ 91 addr = EF_SYMADDR(ef, symidx); 92 *where = addr; 93 break; 94 default: 95 warnx("unhandled relocation type %d", (int)rtype); 96 } 97 return (0); 98 } 99