mdreloc.c revision 1.11
1 /* $NetBSD: mdreloc.c,v 1.11 2002/09/05 21:31:36 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(ELF_R_SYM(rela->r_info), obj, &defobj, 102 true); 103 if (def == NULL) 104 return -1; 105 106 new_value = (Elf_Addr) 107 (defobj->relocbase + def->st_value + rela->r_addend); 108 rdbg(dodebug, ("bind now %d/fixup in %s --> old=%p new=%p", 109 (int)bind_now, 110 defobj->strtab + def->st_name, 111 (void *)*where, (void *)new_value)); 112 } else { 113 if (!obj->mainprog) { 114 /* Just relocate the GOT slots pointing into the PLT */ 115 new_value = *where + (Elf_Addr) obj->relocbase; 116 rdbg(dodebug, ("fixup !main in %s --> %p", obj->path, 117 (void *)(unsigned long)*where)); 118 } else { 119 return 0; 120 } 121 } 122 /* 123 * Since this page is probably copy-on-write, let's not write 124 * it unless we really really have to. 125 */ 126 if (*where != new_value) 127 *where = new_value; 128 if (addrp != NULL) 129 *addrp = *(caddr_t *)(obj->relocbase + rela->r_offset) - 130 rela->r_addend; 131 return 0; 132 } 133 134 void 135 _rtld_setup_pltgot(const Obj_Entry *obj) 136 { 137 obj->pltgot[1] = (Elf_Addr) obj; 138 obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start; 139 } 140 141 int 142 _rtld_relocate_nonplt_objects(Obj_Entry *obj, bool dodebug) 143 { 144 const Elf_Rela *rela; 145 146 for (rela = obj->rela; rela < obj->relalim; rela++) { 147 Elf64_Addr *where64; 148 Elf32_Addr *where32; 149 const Elf_Sym *def; 150 const Obj_Entry *defobj; 151 Elf64_Addr tmp64; 152 Elf32_Addr tmp32; 153 unsigned long symnum; 154 155 where64 = (Elf64_Addr *)(obj->relocbase + rela->r_offset); 156 where32 = (Elf32_Addr *)where64; 157 symnum = ELF_R_SYM(rela->r_info); 158 159 switch (ELF_R_TYPE(rela->r_info)) { 160 case R_TYPE(NONE): 161 break; 162 163 case R_TYPE(32): /* word32 S + A, truncate */ 164 case R_TYPE(32S): /* word32 S + A, signed truncate */ 165 case R_TYPE(GOT32): /* word32 G + A (XXX can we see these?) */ 166 def = _rtld_find_symdef(symnum, obj, &defobj, false); 167 if (def == NULL) 168 return -1; 169 tmp32 = (Elf32_Addr)(u_long)(defobj->relocbase + 170 def->st_value + rela->r_addend); 171 172 if (*where32 != tmp32) 173 *where32 = tmp32; 174 rdbg(dodebug, ("32/32S %s in %s --> %p in %s", 175 obj->strtab + obj->symtab[symnum].st_name, 176 obj->path, (void *)(unsigned long)*where32, 177 defobj->path)); 178 break; 179 case R_TYPE(64): /* word64 S + A */ 180 def = _rtld_find_symdef(symnum, obj, &defobj, false); 181 if (def == NULL) 182 return -1; 183 184 tmp64 = (Elf64_Addr)(defobj->relocbase + def->st_value + 185 rela->r_addend); 186 187 if (*where64 != tmp64) 188 *where64 = tmp64; 189 rdbg(dodebug, ("64 %s in %s --> %p in %s", 190 obj->strtab + obj->symtab[symnum].st_name, 191 obj->path, (void *)*where64, defobj->path)); 192 break; 193 case R_TYPE(PC32): /* word32 S + A - P */ 194 def = _rtld_find_symdef(symnum, obj, &defobj, false); 195 if (def == NULL) 196 return -1; 197 tmp32 = (Elf32_Addr)(u_long)(defobj->relocbase + 198 def->st_value + rela->r_addend - 199 (Elf64_Addr)where64); 200 if (*where32 != tmp32) 201 *where32 = tmp32; 202 rdbg(dodebug, ("PC32 %s in %s --> %p in %s", 203 obj->strtab + obj->symtab[symnum].st_name, 204 obj->path, (void *)(unsigned long)*where32, 205 defobj->path)); 206 break; 207 case R_TYPE(GLOB_DAT): /* word64 S */ 208 def = _rtld_find_symdef(symnum, obj, &defobj, false); 209 if (def == NULL) 210 return -1; 211 212 tmp64 = (Elf64_Addr)(defobj->relocbase + def->st_value); 213 214 if (*where64 != tmp64) 215 *where64 = tmp64; 216 rdbg(dodebug, ("64 %s in %s --> %p in %s", 217 obj->strtab + obj->symtab[symnum].st_name, 218 obj->path, (void *)*where64, defobj->path)); 219 break; 220 case R_TYPE(RELATIVE): /* word64 B + A */ 221 tmp64 = (Elf64_Addr)(obj->relocbase + rela->r_addend); 222 if (*where64 != tmp64) 223 *where64 = tmp64; 224 rdbg(dodebug, ("RELATIVE in %s --> %p", obj->path, 225 (void *)*where64)); 226 break; 227 228 case R_TYPE(COPY): 229 rdbg(dodebug, ("COPY")); 230 break; 231 232 default: 233 rdbg(dodebug, ("sym = %lu, type = %lu, offset = %p, " 234 "addend = %p, contents = %p, symbol = %s", 235 symnum, (u_long)ELF_R_TYPE(rela->r_info), 236 (void *)rela->r_offset, (void *)rela->r_addend, 237 (void *)*where64, 238 obj->strtab + obj->symtab[symnum].st_name)); 239 _rtld_error("%s: Unsupported relocation type %ld " 240 "in non-PLT relocations\n", 241 obj->path, (u_long) ELF_R_TYPE(rela->r_info)); 242 return -1; 243 } 244 } 245 return 0; 246 } 247
Indexes created Thu Oct 02 14:10:14 GMT 2025