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 "kldelf.h" 40 41 /* 42 * Apply relocations to the values obtained from the file. `relbase' is the 43 * target relocation address of the section, and `dataoff/len' is the region 44 * that is to be relocated, and has been copied to *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 addr, addend; 52 GElf_Size rtype, symidx; 53 const GElf_Rel *rel; 54 const GElf_Rela *rela; 55 56 switch (reltype) { 57 case ELF_T_REL: 58 rel = (const GElf_Rel *)reldata; 59 where = (char *)dest + (relbase + rel->r_offset - dataoff); 60 addend = 0; 61 rtype = GELF_R_TYPE(rel->r_info); 62 symidx = GELF_R_SYM(rel->r_info); 63 break; 64 case ELF_T_RELA: 65 rela = (const GElf_Rela *)reldata; 66 where = (char *)dest + (relbase + rela->r_offset - dataoff); 67 addend = rela->r_addend; 68 rtype = GELF_R_TYPE(rela->r_info); 69 symidx = GELF_R_SYM(rela->r_info); 70 break; 71 default: 72 return (EINVAL); 73 } 74 75 if (where < (char *)dest || where >= (char *)dest + len) 76 return (0); 77 78 if (reltype == ELF_T_REL) { 79 if (elf_class(ef) == ELFCLASS64) { 80 if (elf_encoding(ef) == ELFDATA2LSB) 81 addend = le64dec(where); 82 else 83 addend = be64dec(where); 84 } else { 85 if (elf_encoding(ef) == ELFDATA2LSB) 86 addend = le32dec(where); 87 else 88 addend = be32dec(where); 89 } 90 } 91 92 switch (rtype) { 93 case R_MIPS_64: /* S + A */ 94 addr = EF_SYMADDR(ef, symidx) + addend; 95 if (elf_encoding(ef) == ELFDATA2LSB) 96 le64enc(where, addr); 97 else 98 be64enc(where, addr); 99 break; 100 case R_MIPS_32: /* S + A */ 101 addr = EF_SYMADDR(ef, symidx) + addend; 102 if (elf_encoding(ef) == ELFDATA2LSB) 103 le32enc(where, addr); 104 else 105 be32enc(where, addr); 106 break; 107 default: 108 warnx("unhandled relocation type %d", (int)rtype); 109 } 110 return (0); 111 } 112 113 ELF_RELOC(ELFCLASS32, ELFDATA2LSB, EM_MIPS, ef_mips_reloc); 114 ELF_RELOC(ELFCLASS32, ELFDATA2MSB, EM_MIPS, ef_mips_reloc); 115 ELF_RELOC(ELFCLASS64, ELFDATA2LSB, EM_MIPS, ef_mips_reloc); 116 ELF_RELOC(ELFCLASS64, ELFDATA2MSB, EM_MIPS, ef_mips_reloc); 117