mdreloc.c revision 1.9
1 /* $NetBSD: mdreloc.c,v 1.9 2002/09/05 20:08:20 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 extern Elf64_Addr _GLOBAL_OFFSET_TABLE_[]; 85 86 int 87 _rtld_relocate_plt_object(Obj_Entry *obj, const Elf_Rela *rela, caddr_t *addrp, 88 bool bind_now, bool dodebug) 89 { 90 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 91 Elf_Addr new_value; 92 93 /* Fully resolve procedure addresses now */ 94 95 if (bind_now || obj->pltgot == NULL) { 96 const Elf_Sym *def; 97 const Obj_Entry *defobj; 98 99 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JUMP_SLOT)); 100 101 def = _rtld_find_symdef(rela->r_info, obj, &defobj, true); 102 if (def == NULL) 103 return -1; 104 105 new_value = (Elf_Addr) 106 (defobj->relocbase + def->st_value + rela->r_addend); 107 rdbg(dodebug, ("bind now %d/fixup in %s --> old=%p new=%p", 108 (int)bind_now, 109 defobj->strtab + def->st_name, 110 (void *)*where, (void *)new_value)); 111 } else { 112 if (!obj->mainprog) { 113 /* Just relocate the GOT slots pointing into the PLT */ 114 new_value = *where + (Elf_Addr) obj->relocbase; 115 rdbg(dodebug, ("fixup !main in %s --> %p", obj->path, 116 (void *)(unsigned long)*where)); 117 } else { 118 return 0; 119 } 120 } 121 /* 122 * Since this page is probably copy-on-write, let's not write 123 * it unless we really really have to. 124 */ 125 if (*where != new_value) 126 *where = new_value; 127 if (addrp != NULL) 128 *addrp = *(caddr_t *)(obj->relocbase + rela->r_offset) - 129 rela->r_addend; 130 return 0; 131 } 132 133 void 134 _rtld_setup_pltgot(const Obj_Entry *obj) 135 { 136 obj->pltgot[1] = (Elf_Addr) obj; 137 obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start; 138 } 139 140 int 141 _rtld_relocate_nonplt_objects(Obj_Entry *obj, bool dodebug) 142 { 143 const Elf_Rela *rela; 144 145 for (rela = obj->rela; rela < obj->relalim; rela++) { 146 Elf64_Addr *where64; 147 Elf32_Addr *where32; 148 const Elf_Sym *def; 149 const Obj_Entry *defobj; 150 Elf64_Addr tmp64; 151 Elf32_Addr tmp32; 152 153 where64 = (Elf64_Addr *)(obj->relocbase + rela->r_offset); 154 where32 = (Elf32_Addr *)where64; 155 156 switch (ELF_R_TYPE(rela->r_info)) { 157 case R_TYPE(NONE): 158 break; 159 160 case R_TYPE(32): /* word32 S + A, truncate */ 161 case R_TYPE(32S): /* word32 S + A, signed truncate */ 162 case R_TYPE(GOT32): /* word32 G + A (XXX can we see these?) */ 163 def = _rtld_find_symdef(rela->r_info, obj, &defobj, 164 false); 165 if (def == NULL) 166 return -1; 167 tmp32 = (Elf32_Addr)(u_long)(defobj->relocbase + 168 def->st_value + rela->r_addend); 169 170 if (*where32 != tmp32) 171 *where32 = tmp32; 172 rdbg(dodebug, ("32/32S %s in %s --> %p in %s", 173 defobj->strtab + def->st_name, obj->path, 174 (void *)(unsigned long)*where32, defobj->path)); 175 break; 176 case R_TYPE(64): /* word64 S + A */ 177 def = _rtld_find_symdef(rela->r_info, obj, &defobj, 178 false); 179 if (def == NULL) 180 return -1; 181 182 tmp64 = (Elf64_Addr)(defobj->relocbase + def->st_value + 183 rela->r_addend); 184 185 if (*where64 != tmp64) 186 *where64 = tmp64; 187 rdbg(dodebug, ("64 %s in %s --> %p in %s", 188 defobj->strtab + def->st_name, obj->path, 189 (void *)*where64, defobj->path)); 190 break; 191 case R_TYPE(PC32): /* word32 S + A - P */ 192 def = _rtld_find_symdef(rela->r_info, obj, &defobj, 193 false); 194 if (def == NULL) 195 return -1; 196 tmp32 = (Elf32_Addr)(u_long)(defobj->relocbase + 197 def->st_value + rela->r_addend - 198 (Elf64_Addr)where64); 199 if (*where32 != tmp32) 200 *where32 = tmp32; 201 rdbg(dodebug, ("PC32 %s in %s --> %p in %s", 202 defobj->strtab + def->st_name, obj->path, 203 (void *)(unsigned long)*where32, defobj->path)); 204 break; 205 case R_TYPE(GLOB_DAT): /* word64 S */ 206 def = _rtld_find_symdef(rela->r_info, obj, &defobj, 207 false); 208 if (def == NULL) 209 return -1; 210 211 tmp64 = (Elf64_Addr)(defobj->relocbase + def->st_value); 212 213 if (*where64 != tmp64) 214 *where64 = tmp64; 215 rdbg(dodebug, ("64 %s in %s --> %p in %s", 216 defobj->strtab + def->st_name, obj->path, 217 (void *)*where64, defobj->path)); 218 break; 219 case R_TYPE(RELATIVE): /* word64 B + A */ 220 tmp64 = (Elf64_Addr)(obj->relocbase + rela->r_addend); 221 if (*where64 != tmp64) 222 *where64 = tmp64; 223 rdbg(dodebug, ("RELATIVE in %s --> %p", obj->path, 224 (void *)*where64)); 225 break; 226 227 case R_TYPE(COPY): 228 rdbg(dodebug, ("COPY")); 229 break; 230 231 default: 232 def = _rtld_find_symdef(rela->r_info, obj, &defobj, 233 true); 234 rdbg(dodebug, ("sym = %lu, type = %lu, offset = %p, " 235 "addend = %p, contents = %p, symbol = %s", 236 (u_long)ELF_R_SYM(rela->r_info), 237 (u_long)ELF_R_TYPE(rela->r_info), 238 (void *)rela->r_offset, (void *)rela->r_addend, 239 (void *)*where64, 240 def ? defobj->strtab + def->st_name : "??")); 241 _rtld_error("%s: Unsupported relocation type %ld " 242 "in non-PLT relocations\n", 243 obj->path, (u_long) ELF_R_TYPE(rela->r_info)); 244 return -1; 245 } 246 } 247 return 0; 248 } 249
Indexes created Thu Oct 02 01:09:59 GMT 2025