mdreloc.c revision 1.6
1 /* $NetBSD: mdreloc.c,v 1.6 2002/09/05 15:38:33 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_nonplt_object(Obj_Entry *obj, const Elf_Rela *rela, bool dodebug) 88 { 89 Elf64_Addr *where64; 90 Elf32_Addr *where32; 91 const Elf_Sym *def; 92 const Obj_Entry *defobj; 93 Elf64_Addr tmp64; 94 Elf32_Addr tmp32; 95 96 where64 = (Elf64_Addr *)(obj->relocbase + rela->r_offset); 97 where32 = (Elf32_Addr *)where64; 98 99 switch (ELF_R_TYPE(rela->r_info)) { 100 101 case R_TYPE(NONE): 102 break; 103 104 case R_TYPE(32): /* word32 S + A, truncate */ 105 case R_TYPE(32S): /* word32 S + A, signed truncate */ 106 case R_TYPE(GOT32): /* word32 G + A (XXX can we see these?) */ 107 def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj, 108 &defobj, false); 109 if (def == NULL) 110 return -1; 111 tmp32 = (Elf32_Addr)(u_long)(defobj->relocbase + def->st_value + 112 rela->r_addend); 113 114 if (*where32 != tmp32) 115 *where32 = tmp32; 116 rdbg(dodebug, ("32/32S %s in %s --> %p in %s", 117 defobj->strtab + def->st_name, obj->path, 118 (void *)(unsigned long)*where32, defobj->path)); 119 break; 120 case R_TYPE(64): /* word64 S + A */ 121 def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj, 122 &defobj, false); 123 if (def == NULL) 124 return -1; 125 126 tmp64 = (Elf64_Addr)(defobj->relocbase + def->st_value + 127 rela->r_addend); 128 129 if (*where64 != tmp64) 130 *where64 = tmp64; 131 rdbg(dodebug, ("64 %s in %s --> %p in %s", 132 defobj->strtab + def->st_name, obj->path, 133 (void *)*where64, defobj->path)); 134 break; 135 case R_TYPE(PC32): /* word32 S + A - P */ 136 def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj, 137 &defobj, false); 138 if (def == NULL) 139 return -1; 140 tmp32 = (Elf32_Addr)(u_long)(defobj->relocbase + def->st_value + 141 rela->r_addend - (Elf64_Addr)where64); 142 if (*where32 != tmp32) 143 *where32 = tmp32; 144 rdbg(dodebug, ("PC32 %s in %s --> %p in %s", 145 defobj->strtab + def->st_name, obj->path, 146 (void *)(unsigned long)*where32, defobj->path)); 147 break; 148 case R_TYPE(GLOB_DAT): /* word64 S */ 149 def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj, 150 &defobj, false); 151 if (def == NULL) 152 return -1; 153 154 tmp64 = (Elf64_Addr)(defobj->relocbase + def->st_value); 155 156 if (*where64 != tmp64) 157 *where64 = tmp64; 158 rdbg(dodebug, ("64 %s in %s --> %p in %s", 159 defobj->strtab + def->st_name, obj->path, 160 (void *)*where64, defobj->path)); 161 break; 162 case R_TYPE(RELATIVE): /* word64 B + A */ 163 tmp64 = (Elf64_Addr)(obj->relocbase + rela->r_addend); 164 if (*where64 != tmp64) 165 *where64 = tmp64; 166 rdbg(dodebug, ("RELATIVE in %s --> %p", obj->path, 167 (void *)*where64)); 168 break; 169 170 case R_TYPE(COPY): 171 rdbg(dodebug, ("COPY")); 172 break; 173 174 default: 175 def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj, 176 &defobj, true); 177 rdbg(dodebug, ("sym = %lu, type = %lu, offset = %p, " 178 "addend = %p, contents = %p, symbol = %s", 179 (u_long)ELF_R_SYM(rela->r_info), 180 (u_long)ELF_R_TYPE(rela->r_info), 181 (void *)rela->r_offset, (void *)rela->r_addend, 182 (void *)*where64, 183 def ? defobj->strtab + def->st_name : "??")); 184 _rtld_error("%s: Unsupported relocation type %ld " 185 "in non-PLT relocations\n", 186 obj->path, (u_long) ELF_R_TYPE(rela->r_info)); 187 return -1; 188 } 189 return 0; 190 } 191 192 193 194 int 195 _rtld_relocate_plt_object(Obj_Entry *obj, const Elf_Rela *rela, caddr_t *addrp, 196 bool bind_now, bool dodebug) 197 { 198 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 199 Elf_Addr new_value; 200 201 /* Fully resolve procedure addresses now */ 202 203 if (bind_now || obj->pltgot == NULL) { 204 const Elf_Sym *def; 205 const Obj_Entry *defobj; 206 207 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JUMP_SLOT)); 208 209 def = _rtld_find_symdef(_rtld_objlist, rela->r_info, NULL, obj, 210 &defobj, true); 211 if (def == NULL) 212 return -1; 213 214 new_value = (Elf_Addr) 215 (defobj->relocbase + def->st_value + rela->r_addend); 216 rdbg(dodebug, ("bind now %d/fixup in %s --> old=%p new=%p", 217 (int)bind_now, 218 defobj->strtab + def->st_name, 219 (void *)*where, (void *)new_value)); 220 } else { 221 if (!obj->mainprog) { 222 /* Just relocate the GOT slots pointing into the PLT */ 223 new_value = *where + (Elf_Addr) obj->relocbase; 224 rdbg(dodebug, ("fixup !main in %s --> %p", obj->path, 225 (void *)(unsigned long)*where)); 226 } else { 227 return 0; 228 } 229 } 230 /* 231 * Since this page is probably copy-on-write, let's not write 232 * it unless we really really have to. 233 */ 234 if (*where != new_value) 235 *where = new_value; 236 if (addrp != NULL) 237 *addrp = *(caddr_t *)(obj->relocbase + rela->r_offset) - 238 rela->r_addend; 239 return 0; 240 } 241 242 void 243 _rtld_setup_pltgot(const Obj_Entry *obj) 244 { 245 obj->pltgot[1] = (Elf_Addr) obj; 246 obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start; 247 } 248
Indexes created Thu Oct 02 14:10:14 GMT 2025