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 33 #include <sys/endian.h> 34 35 #include <err.h> 36 #include <errno.h> 37 #include <gelf.h> 38 39 #include "ef.h" 40 41 /* 42 * Apply relocations to the values we got from the file. `relbase' is the 43 * target relocation address of the section, and `dataoff' is the target 44 * relocation address of the data in `dest'. 45 */ 46 static int 47 ef_mips_reloc(struct elf_file *ef, const void *reldata, Elf_Type reltype, 48 GElf_Addr relbase, GElf_Addr dataoff, size_t len, void *dest) 49 { 50 char *where; 51 GElf_Addr val; 52 const GElf_Rel *rel; 53 const GElf_Rela *rela; 54 GElf_Addr addend, addr; 55 GElf_Size rtype, symidx; 56 57 switch (reltype) { 58 case ELF_T_REL: 59 rel = (const GElf_Rel *)reldata; 60 where = (char *)dest + relbase + rel->r_offset - dataoff; 61 addend = 0; 62 rtype = GELF_R_TYPE(rel->r_info); 63 symidx = GELF_R_SYM(rel->r_info); 64 break; 65 case ELF_T_RELA: 66 rela = (const GElf_Rela *)reldata; 67 where = (char *)dest + relbase + rela->r_offset - dataoff; 68 addend = rela->r_addend; 69 rtype = GELF_R_TYPE(rela->r_info); 70 symidx = GELF_R_SYM(rela->r_info); 71 break; 72 default: 73 return (EINVAL); 74 } 75 76 if (where < (char *)dest || where >= (char *)dest + len) 77 return (0); 78 79 if (reltype == ELF_T_REL) { 80 if (elf_class(ef) == ELFCLASS64) { 81 if (elf_encoding(ef) == ELFDATA2LSB) 82 addend = le64dec(where); 83 else 84 addend = be64dec(where); 85 } else { 86 if (elf_encoding(ef) == ELFDATA2LSB) 87 addend = le32dec(where); 88 else 89 addend = be32dec(where); 90 } 91 } 92 93 switch (rtype) { 94 case R_MIPS_64: /* S + A */ 95 addr = EF_SYMADDR(ef, symidx); 96 val = addr + addend; 97 if (elf_encoding(ef) == ELFDATA2LSB) 98 le64enc(where, val); 99 else 100 be64enc(where, val); 101 break; 102 case R_MIPS_32: /* S + A */ 103 addr = EF_SYMADDR(ef, symidx); 104 val = addr + addend; 105 if (elf_encoding(ef) == ELFDATA2LSB) 106 le32enc(where, val); 107 else 108 be32enc(where, val); 109 break; 110 default: 111 warnx("unhandled relocation type %d", (int)rtype); 112 } 113 return (0); 114 } 115 116 ELF_RELOC(ELFCLASS32, ELFDATA2LSB, EM_MIPS, ef_mips_reloc); 117 ELF_RELOC(ELFCLASS32, ELFDATA2MSB, EM_MIPS, ef_mips_reloc); 118 ELF_RELOC(ELFCLASS64, ELFDATA2LSB, EM_MIPS, ef_mips_reloc); 119 ELF_RELOC(ELFCLASS64, ELFDATA2MSB, EM_MIPS, ef_mips_reloc); 120