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/kernel.h> 30 #include <sys/systm.h> 31 #include <sys/linker.h> 32 #include <sys/sysent.h> 33 #include <sys/imgact_elf.h> 34 #include <sys/syscall.h> 35 #include <sys/signalvar.h> 36 #include <sys/vnode.h> 37 #include <machine/elf.h> 38 #include <machine/md_var.h> 39 40 static struct sysentvec elf64_dragonfly_sysvec = { 41 .sv_size = SYS_MAXSYSCALL, 42 .sv_table = sysent, 43 .sv_sigsize = 0, 44 .sv_sigtbl = NULL, 45 .sv_errsize = 0, 46 .sv_errtbl = NULL, 47 .sv_transtrap = NULL, 48 .sv_fixup = __elfN(dragonfly_fixup), 49 .sv_sendsig = sendsig, 50 .sv_sigcode = sigcode, 51 .sv_szsigcode = &szsigcode, 52 .sv_name = "DragonFly ELF64", 53 .sv_coredump = __elfN(coredump), 54 .sv_imgact_try = NULL, 55 .sv_minsigstksz = MINSIGSTKSZ, 56 }; 57 58 static Elf64_Brandinfo dragonfly_brand_info = { 59 .brand = ELFOSABI_NONE, 60 .machine = EM_X86_64, 61 .compat_3_brand = "DragonFly", 62 .emul_path = NULL, 63 .interp_path = "/libexec/ld-elf.so.2", 64 .sysvec = &elf64_dragonfly_sysvec, 65 .interp_newpath = NULL, 66 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE, 67 .brand_note = &elf64_dragonfly_brandnote, 68 }; 69 70 SYSINIT(elf64, SI_SUB_EXEC, SI_ORDER_FIRST, 71 (sysinit_cfunc_t) elf64_insert_brand_entry, 72 &dragonfly_brand_info); 73 74 /* Process one elf relocation with addend. */ 75 static int 76 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 77 int type, int local, elf_lookup_fn lookup) 78 { 79 Elf64_Addr *where, val; 80 Elf32_Addr *where32, val32; 81 Elf_Addr addr; 82 Elf_Addr addend; 83 Elf_Size rtype, symidx; 84 const Elf_Rel *rel; 85 const Elf_Rela *rela; 86 87 switch (type) { 88 case ELF_RELOC_REL: 89 rel = (const Elf_Rel *)data; 90 where = (Elf_Addr *) (relocbase + rel->r_offset); 91 rtype = ELF_R_TYPE(rel->r_info); 92 symidx = ELF_R_SYM(rel->r_info); 93 /* Addend is 32 bit on 32 bit relocs */ 94 switch (rtype) { 95 case R_X86_64_PC32: 96 case R_X86_64_PLT32: 97 case R_X86_64_32: 98 case R_X86_64_32S: 99 addend = *(Elf32_Addr *)where; 100 break; 101 default: 102 addend = *where; 103 break; 104 } 105 break; 106 case ELF_RELOC_RELA: 107 rela = (const Elf_Rela *)data; 108 where = (Elf_Addr *) (relocbase + rela->r_offset); 109 addend = rela->r_addend; 110 rtype = ELF_R_TYPE(rela->r_info); 111 symidx = ELF_R_SYM(rela->r_info); 112 break; 113 default: 114 panic("unknown reloc type %d", type); 115 } 116 117 switch (rtype) { 118 119 case R_X86_64_NONE: /* none */ 120 break; 121 122 case R_X86_64_64: /* S + A */ 123 if (lookup(lf, symidx, 1, &addr)) 124 return -1; 125 val = addr + addend; 126 if (*where != val) 127 *where = val; 128 break; 129 130 case R_X86_64_PC32: /* S + A - P */ 131 case R_X86_64_PLT32: /* XXX assume PLT as S too */ 132 if (lookup(lf, symidx, 1, &addr)) 133 return -1; 134 where32 = (Elf32_Addr *)where; 135 val32 = (Elf32_Addr)(addr + addend - (Elf_Addr)where); 136 if (*where32 != val32) 137 *where32 = val32; 138 break; 139 140 case R_X86_64_32: /* S + A zero extend */ 141 case R_X86_64_32S: /* S + A sign extend */ 142 if (lookup(lf, symidx, 1, &addr)) 143 return -1; 144 val32 = (Elf32_Addr)(addr + addend); 145 where32 = (Elf32_Addr *)where; 146 if (*where32 != val32) 147 *where32 = val32; 148 break; 149 150 case R_X86_64_COPY: /* none */ 151 /* 152 * There shouldn't be copy relocations in kernel 153 * objects. 154 */ 155 kprintf("kldload: unexpected R_COPY relocation\n"); 156 return -1; 157 break; 158 159 case R_X86_64_GLOB_DAT: /* S */ 160 case R_X86_64_JMP_SLOT: /* XXX need addend + offset */ 161 if (lookup(lf, symidx, 1, &addr)) 162 return -1; 163 if (*where != addr) 164 *where = addr; 165 break; 166 167 case R_X86_64_RELATIVE: /* B + A */ 168 addr = relocbase + addend; 169 val = addr; 170 if (*where != val) 171 *where = val; 172 break; 173 174 default: 175 kprintf("kldload: unexpected relocation type %ld\n", 176 rtype); 177 return -1; 178 } 179 return(0); 180 } 181 182 int 183 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 184 elf_lookup_fn lookup) 185 { 186 187 return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup)); 188 } 189 190 int 191 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 192 int type, elf_lookup_fn lookup) 193 { 194 195 return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup)); 196 } 197