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/types.h> 34 #include <machine/elf.h> 35 36 #include <err.h> 37 #include <errno.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 int 47 ef_reloc(struct elf_file *ef, const void *reldata, int reltype, Elf_Off relbase, 48 Elf_Off dataoff, size_t len, void *dest) 49 { 50 Elf_Addr *where, val; 51 const Elf_Rel *rel; 52 const Elf_Rela *rela; 53 Elf_Addr addend, addr; 54 Elf_Size rtype, symidx; 55 56 switch (reltype) { 57 case EF_RELOC_REL: 58 rel = (const Elf_Rel *)reldata; 59 where = (Elf_Addr *)((char *)dest + relbase + rel->r_offset - 60 dataoff); 61 addend = 0; 62 rtype = ELF_R_TYPE(rel->r_info); 63 symidx = ELF_R_SYM(rel->r_info); 64 break; 65 case EF_RELOC_RELA: 66 rela = (const Elf_Rela *)reldata; 67 where = (Elf_Addr *)((char *)dest + relbase + rela->r_offset - 68 dataoff); 69 addend = rela->r_addend; 70 rtype = ELF_R_TYPE(rela->r_info); 71 symidx = ELF_R_SYM(rela->r_info); 72 break; 73 default: 74 return (EINVAL); 75 } 76 77 if ((char *)where < (char *)dest || (char *)where >= (char *)dest + len) 78 return (0); 79 80 if (reltype == EF_RELOC_REL) 81 addend = *where; 82 83 switch (rtype) { 84 #ifdef __LP64__ 85 case R_MIPS_64: /* S + A */ 86 #else 87 case R_MIPS_32: /* S + A */ 88 #endif 89 addr = EF_SYMADDR(ef, symidx); 90 val = addr + addend; 91 *where = val; 92 break; 93 default: 94 warnx("unhandled relocation type %d", (int)rtype); 95 } 96 return (0); 97 } 98