1 /*- 2 * Copyright 1996-1998 John D. Polstra. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 * 25 * $FreeBSD: src/sys/i386/i386/elf_machdep.c,v 1.8 1999/12/21 11:14:02 eivind Exp $ 26 */ 27 28 #include <sys/param.h> 29 #include <sys/systm.h> 30 #include <sys/linker.h> 31 #include <machine/elf.h> 32 33 /* Process one elf relocation with addend. */ 34 static int 35 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 36 int type, int local, elf_lookup_fn lookup) 37 { 38 Elf64_Addr *where, val; 39 Elf32_Addr *where32, val32; 40 Elf_Addr addr; 41 Elf_Addr addend; 42 Elf_Size rtype, symidx; 43 const Elf_Rel *rel; 44 const Elf_Rela *rela; 45 46 switch (type) { 47 case ELF_RELOC_REL: 48 rel = (const Elf_Rel *)data; 49 where = (Elf_Addr *) (relocbase + rel->r_offset); 50 rtype = ELF_R_TYPE(rel->r_info); 51 symidx = ELF_R_SYM(rel->r_info); 52 /* Addend is 32 bit on 32 bit relocs */ 53 switch (rtype) { 54 case R_X86_64_PC32: 55 case R_X86_64_32: 56 case R_X86_64_32S: 57 addend = *(Elf32_Addr *)where; 58 break; 59 default: 60 addend = *where; 61 break; 62 } 63 break; 64 case ELF_RELOC_RELA: 65 rela = (const Elf_Rela *)data; 66 where = (Elf_Addr *) (relocbase + rela->r_offset); 67 addend = rela->r_addend; 68 rtype = ELF_R_TYPE(rela->r_info); 69 symidx = ELF_R_SYM(rela->r_info); 70 break; 71 default: 72 panic("unknown reloc type %d\n", type); 73 } 74 75 switch (rtype) { 76 77 case R_X86_64_NONE: /* none */ 78 break; 79 80 case R_X86_64_64: /* S + A */ 81 if (lookup(lf, symidx, 1, &addr)) 82 return -1; 83 val = addr + addend; 84 if (*where != val) 85 *where = val; 86 break; 87 88 case R_X86_64_PC32: /* S + A - P */ 89 if (lookup(lf, symidx, 1, &addr)) 90 return -1; 91 where32 = (Elf32_Addr *)where; 92 val32 = (Elf32_Addr)(addr + addend - (Elf_Addr)where); 93 if (*where32 != val32) 94 *where32 = val32; 95 break; 96 97 case R_X86_64_32: /* S + A zero extend */ 98 case R_X86_64_32S: /* S + A sign extend */ 99 if (lookup(lf, symidx, 1, &addr)) 100 return -1; 101 val32 = (Elf32_Addr)(addr + addend); 102 where32 = (Elf32_Addr *)where; 103 if (*where32 != val32) 104 *where32 = val32; 105 break; 106 107 case R_X86_64_COPY: /* none */ 108 /* 109 * There shouldn't be copy relocations in kernel 110 * objects. 111 */ 112 kprintf("kldload: unexpected R_COPY relocation\n"); 113 return -1; 114 break; 115 116 case R_X86_64_GLOB_DAT: /* S */ 117 case R_X86_64_JMP_SLOT: /* XXX need addend + offset */ 118 if (lookup(lf, symidx, 1, &addr)) 119 return -1; 120 if (*where != addr) 121 *where = addr; 122 break; 123 124 case R_X86_64_RELATIVE: /* B + A */ 125 addr = relocbase + addend; 126 val = addr; 127 if (*where != val) 128 *where = val; 129 break; 130 131 default: 132 kprintf("kldload: unexpected relocation type %ld\n", 133 rtype); 134 return -1; 135 } 136 return(0); 137 } 138 139 int 140 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 141 elf_lookup_fn lookup) 142 { 143 144 return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup)); 145 } 146 147 int 148 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 149 int type, elf_lookup_fn lookup) 150 { 151 152 return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup)); 153 } 154