1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2019 John Baldwin <jhb@FreeBSD.org> 5 * 6 * This software was developed by SRI International and the University of 7 * Cambridge Computer Laboratory (Department of Computer Science and 8 * Technology) under DARPA contract HR0011-18-C-0016 ("ECATS"), as part of the 9 * DARPA SSITH research programme. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * $FreeBSD$ 33 */ 34 35 #include <sys/types.h> 36 #include <machine/elf.h> 37 38 #include <err.h> 39 #include <errno.h> 40 41 #include "ef.h" 42 43 /* 44 * Apply relocations to the values we got from the file. `relbase' is the 45 * target relocation address of the section, and `dataoff' is the target 46 * relocation address of the data in `dest'. 47 */ 48 int 49 ef_reloc(struct elf_file *ef, const void *reldata, int reltype, Elf_Off relbase, 50 Elf_Off dataoff, size_t len, void *dest) 51 { 52 Elf_Addr *where, val; 53 const Elf_Rel *rel; 54 const Elf_Rela *rela; 55 Elf_Addr addend, addr; 56 Elf_Size rtype, symidx; 57 58 switch (reltype) { 59 case EF_RELOC_REL: 60 rel = (const Elf_Rel *)reldata; 61 where = (Elf_Addr *)((char *)dest + relbase + rel->r_offset - 62 dataoff); 63 addend = 0; 64 rtype = ELF_R_TYPE(rel->r_info); 65 symidx = ELF_R_SYM(rel->r_info); 66 break; 67 case EF_RELOC_RELA: 68 rela = (const Elf_Rela *)reldata; 69 where = (Elf_Addr *)((char *)dest + relbase + rela->r_offset - 70 dataoff); 71 addend = rela->r_addend; 72 rtype = ELF_R_TYPE(rela->r_info); 73 symidx = ELF_R_SYM(rela->r_info); 74 break; 75 default: 76 return (EINVAL); 77 } 78 79 if ((char *)where < (char *)dest || (char *)where >= (char *)dest + len) 80 return (0); 81 82 if (reltype == EF_RELOC_REL) 83 addend = *where; 84 85 switch (rtype) { 86 #ifdef __LP64__ 87 case R_MIPS_64: /* S + A */ 88 #else 89 case R_MIPS_32: /* S + A */ 90 #endif 91 addr = EF_SYMADDR(ef, symidx); 92 val = addr + addend; 93 *where = val; 94 break; 95 default: 96 warnx("unhandled relocation type %d", (int)rtype); 97 } 98 return (0); 99 } 100