mdreloc.c revision 1.18
1 /* $NetBSD: mdreloc.c,v 1.18 2002/09/25 08:37:57 mycroft Exp $ */ 2 3 /* 4 * Copyright (c) 2001 Wasabi Systems, Inc. 5 * All rights reserved. 6 * 7 * Written by Frank van der Linden for Wasabi Systems, Inc. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed for the NetBSD Project by 20 * Wasabi Systems, Inc. 21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse 22 * or promote products derived from this software without specific prior 23 * written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC 29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35 * POSSIBILITY OF SUCH DAMAGE. 36 */ 37 38 /* 39 * Copyright 1996 John D. Polstra. 40 * Copyright 1996 Matt Thomas <matt (at) 3am-software.com> 41 * All rights reserved. 42 * 43 * Redistribution and use in source and binary forms, with or without 44 * modification, are permitted provided that the following conditions 45 * are met: 46 * 1. Redistributions of source code must retain the above copyright 47 * notice, this list of conditions and the following disclaimer. 48 * 2. Redistributions in binary form must reproduce the above copyright 49 * notice, this list of conditions and the following disclaimer in the 50 * documentation and/or other materials provided with the distribution. 51 * 3. All advertising materials mentioning features or use of this software 52 * must display the following acknowledgement: 53 * This product includes software developed by John Polstra. 54 * 4. The name of the author may not be used to endorse or promote products 55 * derived from this software without specific prior written permission. 56 * 57 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 58 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 59 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 60 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 61 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 62 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 63 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 64 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 65 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 66 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 67 */ 68 69 #include <sys/types.h> 70 #include <sys/mman.h> 71 #include <err.h> 72 #include <errno.h> 73 #include <fcntl.h> 74 #include <stdarg.h> 75 #include <stdio.h> 76 #include <stdlib.h> 77 #include <string.h> 78 #include <unistd.h> 79 #include <elf.h> 80 81 #include "debug.h" 82 #include "rtld.h" 83 84 void _rtld_bind_start(void); 85 caddr_t _rtld_bind __P((const Obj_Entry *, Elf_Word)); 86 87 void 88 _rtld_setup_pltgot(const Obj_Entry *obj) 89 { 90 obj->pltgot[1] = (Elf_Addr) obj; 91 obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start; 92 } 93 94 int 95 _rtld_relocate_nonplt_objects(obj, self) 96 const Obj_Entry *obj; 97 bool self; 98 { 99 const Elf_Rela *rela; 100 101 for (rela = obj->rela; rela < obj->relalim; rela++) { 102 Elf64_Addr *where64; 103 Elf32_Addr *where32; 104 const Elf_Sym *def; 105 const Obj_Entry *defobj; 106 Elf64_Addr tmp64; 107 Elf32_Addr tmp32; 108 unsigned long symnum; 109 110 where64 = (Elf64_Addr *)(obj->relocbase + rela->r_offset); 111 where32 = (Elf32_Addr *)where64; 112 symnum = ELF_R_SYM(rela->r_info); 113 114 switch (ELF_R_TYPE(rela->r_info)) { 115 case R_TYPE(NONE): 116 break; 117 118 case R_TYPE(32): /* word32 S + A, truncate */ 119 case R_TYPE(32S): /* word32 S + A, signed truncate */ 120 case R_TYPE(GOT32): /* word32 G + A (XXX can we see these?) */ 121 def = _rtld_find_symdef(symnum, obj, &defobj, false); 122 if (def == NULL) 123 return -1; 124 tmp32 = (Elf32_Addr)(u_long)(defobj->relocbase + 125 def->st_value + rela->r_addend); 126 127 if (*where32 != tmp32) 128 *where32 = tmp32; 129 rdbg(("32/32S %s in %s --> %p in %s", 130 obj->strtab + obj->symtab[symnum].st_name, 131 obj->path, (void *)(unsigned long)*where32, 132 defobj->path)); 133 break; 134 case R_TYPE(64): /* word64 S + A */ 135 def = _rtld_find_symdef(symnum, obj, &defobj, false); 136 if (def == NULL) 137 return -1; 138 139 tmp64 = (Elf64_Addr)(defobj->relocbase + def->st_value + 140 rela->r_addend); 141 142 if (*where64 != tmp64) 143 *where64 = tmp64; 144 rdbg(("64 %s in %s --> %p in %s", 145 obj->strtab + obj->symtab[symnum].st_name, 146 obj->path, (void *)*where64, defobj->path)); 147 break; 148 case R_TYPE(PC32): /* word32 S + A - P */ 149 def = _rtld_find_symdef(symnum, obj, &defobj, false); 150 if (def == NULL) 151 return -1; 152 tmp32 = (Elf32_Addr)(u_long)(defobj->relocbase + 153 def->st_value + rela->r_addend - 154 (Elf64_Addr)where64); 155 if (*where32 != tmp32) 156 *where32 = tmp32; 157 rdbg(("PC32 %s in %s --> %p in %s", 158 obj->strtab + obj->symtab[symnum].st_name, 159 obj->path, (void *)(unsigned long)*where32, 160 defobj->path)); 161 break; 162 case R_TYPE(GLOB_DAT): /* word64 S */ 163 def = _rtld_find_symdef(symnum, obj, &defobj, false); 164 if (def == NULL) 165 return -1; 166 167 tmp64 = (Elf64_Addr)(defobj->relocbase + def->st_value); 168 169 if (*where64 != tmp64) 170 *where64 = tmp64; 171 rdbg(("64 %s in %s --> %p in %s", 172 obj->strtab + obj->symtab[symnum].st_name, 173 obj->path, (void *)*where64, defobj->path)); 174 break; 175 case R_TYPE(RELATIVE): /* word64 B + A */ 176 tmp64 = (Elf64_Addr)(obj->relocbase + rela->r_addend); 177 if (*where64 != tmp64) 178 *where64 = tmp64; 179 rdbg(("RELATIVE in %s --> %p", obj->path, 180 (void *)*where64)); 181 break; 182 183 case R_TYPE(COPY): 184 rdbg(("COPY")); 185 break; 186 187 default: 188 rdbg(("sym = %lu, type = %lu, offset = %p, " 189 "addend = %p, contents = %p, symbol = %s", 190 symnum, (u_long)ELF_R_TYPE(rela->r_info), 191 (void *)rela->r_offset, (void *)rela->r_addend, 192 (void *)*where64, 193 obj->strtab + obj->symtab[symnum].st_name)); 194 _rtld_error("%s: Unsupported relocation type %ld " 195 "in non-PLT relocations\n", 196 obj->path, (u_long) ELF_R_TYPE(rela->r_info)); 197 return -1; 198 } 199 } 200 return 0; 201 } 202 203 int 204 _rtld_relocate_plt_lazy(obj) 205 const Obj_Entry *obj; 206 { 207 const Elf_Rela *rela; 208 209 if (!obj->isdynamic) 210 return 0; 211 212 for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) { 213 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 214 215 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JUMP_SLOT)); 216 217 /* Just relocate the GOT slots pointing into the PLT */ 218 *where += (Elf_Addr)obj->relocbase; 219 rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where)); 220 } 221 222 return 0; 223 } 224 225 caddr_t 226 _rtld_bind(obj, reloff) 227 const Obj_Entry *obj; 228 Elf_Word reloff; 229 { 230 const Elf_Rela *rela = obj->pltrela + reloff; 231 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 232 Elf_Addr new_value; 233 const Elf_Sym *def; 234 const Obj_Entry *defobj; 235 236 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JUMP_SLOT)); 237 238 def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true); 239 if (def == NULL) 240 return -1; 241 242 new_value = (Elf_Addr)(defobj->relocbase + def->st_value + 243 rela->r_addend); 244 rdbg(("bind now/fixup in %s --> old=%p new=%p", 245 defobj->strtab + def->st_name, (void *)*where, (void *)new_value)); 246 if (*where != new_value) 247 *where = new_value; 248 249 return (caddr_t)(new_value - rela->r_addend); 250 } 251
Indexes created Thu Oct 02 14:10:14 GMT 2025