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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 | /* i386 ELF shared library loader suppport * * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald, * David Engel, Hongjiu Lu and Mitch D'Souza * Copyright (C) 2001-2004 Erik Andersen * * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. The name of the above contributors may not be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include "ldso.h" /* Program to load an ELF binary on a linux system, and run it. References to symbols in sharable libraries can be resolved by either an ELF sharable library or a linux style of shared library. */ extern int _dl_linux_resolve(void); unsigned long _dl_linux_resolver(struct elf_resolve *tpnt, int reloc_entry) { ELF_RELOC *this_reloc; char *strtab; ElfW(Sym) *symtab; int symtab_index; char *rel_addr; char *new_addr; char **got_addr; unsigned long instr_addr; char *symname; rel_addr = (char *)tpnt->dynamic_info[DT_JMPREL]; this_reloc = (ELF_RELOC *)(intptr_t)(rel_addr + reloc_entry); symtab_index = ELF_R_SYM(this_reloc->r_info); symtab = (ElfW(Sym) *)(intptr_t)tpnt->dynamic_info[DT_SYMTAB]; strtab = (char *)tpnt->dynamic_info[DT_STRTAB]; symname = strtab + symtab[symtab_index].st_name; /* Address of the jump instruction to fix up. */ instr_addr = ((unsigned long)this_reloc->r_offset + (unsigned long)tpnt->loadaddr); got_addr = (char **)instr_addr; /* Get the address of the GOT entry. */ new_addr = _dl_find_hash(symname, &_dl_loaded_modules->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT, NULL); if (unlikely(!new_addr)) { _dl_dprintf(2, "%s: can't resolve symbol '%s' in lib '%s'.\n", _dl_progname, symname, tpnt->libname); _dl_exit(1); } #if defined (__SUPPORT_LD_DEBUG__) if ((unsigned long)got_addr < 0x40000000) { if (_dl_debug_bindings) { _dl_dprintf(_dl_debug_file, "\nresolve function: %s", symname); if (_dl_debug_detail) _dl_dprintf(_dl_debug_file, "\n\tpatched: %x ==> %x @ %x", *got_addr, new_addr, got_addr); } } if (!_dl_debug_nofixups) { *got_addr = new_addr; } #else *got_addr = new_addr; #endif return (unsigned long)new_addr; } static int _dl_parse(struct elf_resolve *tpnt, struct r_scope_elem *scope, unsigned long rel_addr, unsigned long rel_size, int (*reloc_fnc)(struct elf_resolve *tpnt, struct r_scope_elem *scope, ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab)) { unsigned int i; char *strtab; ElfW(Sym) *symtab; ELF_RELOC *rpnt; int symtab_index; /* Parse the relocation information. */ rpnt = (ELF_RELOC *)(intptr_t)rel_addr; rel_size /= sizeof(ELF_RELOC); symtab = (ElfW(Sym) *)(intptr_t)tpnt->dynamic_info[DT_SYMTAB]; strtab = (char *)tpnt->dynamic_info[DT_STRTAB]; for (i = 0; i < rel_size; i++, rpnt++) { int res; symtab_index = ELF_R_SYM(rpnt->r_info); debug_sym(symtab, strtab, symtab_index); debug_reloc(symtab, strtab, rpnt); res = reloc_fnc(tpnt, scope, rpnt, symtab, strtab); if (res == 0) continue; _dl_dprintf(2, "\n%s: ", _dl_progname); if (symtab_index) _dl_dprintf(2, "symbol '%s': ", strtab + symtab[symtab_index].st_name); if (unlikely(res < 0)) { int reloc_type = ELF_R_TYPE(rpnt->r_info); _dl_dprintf(2, "can't handle reloc type %x in lib '%s'\n", reloc_type, tpnt->libname); return res; } else if (unlikely(res > 0)) { _dl_dprintf(2, "can't resolve symbol in lib '%s'.\n", tpnt->libname); return res; } } return 0; } static int _dl_do_reloc(struct elf_resolve *tpnt, struct r_scope_elem *scope, ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab) { int reloc_type; int symtab_index; char *symname; struct elf_resolve *tls_tpnt = NULL; unsigned long *reloc_addr; unsigned long symbol_addr; #if defined (__SUPPORT_LD_DEBUG__) unsigned long old_val; #endif struct symbol_ref sym_ref; reloc_addr = (unsigned long *)(intptr_t)(tpnt->loadaddr + (unsigned long)rpnt->r_offset); reloc_type = ELF_R_TYPE(rpnt->r_info); symtab_index = ELF_R_SYM(rpnt->r_info); symbol_addr = 0; sym_ref.sym = &symtab[symtab_index]; sym_ref.tpnt = NULL; symname = strtab + symtab[symtab_index].st_name; if (symtab_index) { symbol_addr = (unsigned long)_dl_find_hash(symname, scope, tpnt, elf_machine_type_class(reloc_type), &sym_ref); /* * We want to allow undefined references to weak symbols - this * might have been intentional. We should not be linking local * symbols here, so all bases should be covered. */ if (unlikely(!symbol_addr && (ELF_ST_TYPE(symtab[symtab_index].st_info) != STT_TLS) && ELF_ST_BIND(symtab[symtab_index].st_info) != STB_WEAK)) return 1; if (_dl_trace_prelink) { _dl_debug_lookup (symname, tpnt, &symtab[symtab_index], &sym_ref, elf_machine_type_class(reloc_type)); } tls_tpnt = sym_ref.tpnt; } else { symbol_addr = symtab[symtab_index].st_value; tls_tpnt = tpnt; } #if defined (__SUPPORT_LD_DEBUG__) old_val = *reloc_addr; #endif switch (reloc_type) { case R_386_NONE: break; case R_386_32: *reloc_addr += symbol_addr; break; case R_386_PC32: *reloc_addr += symbol_addr - (unsigned long)reloc_addr; break; case R_386_GLOB_DAT: case R_386_JMP_SLOT: *reloc_addr = symbol_addr; break; case R_386_RELATIVE: *reloc_addr += (unsigned long)tpnt->loadaddr; break; case R_386_COPY: if (symbol_addr) { #if defined (__SUPPORT_LD_DEBUG__) if (_dl_debug_move) _dl_dprintf(_dl_debug_file, "\n%s move %d bytes from %x to %x", symname, symtab[symtab_index].st_size, symbol_addr, reloc_addr); #endif _dl_memcpy((char *)reloc_addr, (char *)symbol_addr, symtab[symtab_index].st_size); } break; #if defined USE_TLS && USE_TLS case R_386_TLS_DTPMOD32: *reloc_addr = tls_tpnt->l_tls_modid; break; case R_386_TLS_DTPOFF32: /* During relocation all TLS symbols are defined and used. * Therefore the offset is already correct. */ *reloc_addr = symbol_addr; break; case R_386_TLS_TPOFF32: /* The offset is positive, backward from the thread pointer. */ CHECK_STATIC_TLS((struct link_map*) tls_tpnt); *reloc_addr += tls_tpnt->l_tls_offset - symbol_addr; break; case R_386_TLS_TPOFF: /* The offset is negative, forward from the thread pointer. */ CHECK_STATIC_TLS((struct link_map*) tls_tpnt); *reloc_addr += symbol_addr - tls_tpnt->l_tls_offset; break; #endif default: return -1; } #if defined (__SUPPORT_LD_DEBUG__) if (_dl_debug_reloc && _dl_debug_detail) _dl_dprintf(_dl_debug_file, "\n\tpatched: %x ==> %x @ %x\n", old_val, *reloc_addr, reloc_addr); #endif return 0; } static int _dl_do_lazy_reloc(struct elf_resolve *tpnt, struct r_scope_elem *scope, ELF_RELOC *rpnt, ElfW(Sym) *symtab, char *strtab) { int reloc_type; unsigned long *reloc_addr; #if defined (__SUPPORT_LD_DEBUG__) unsigned long old_val; #endif (void)scope; (void)symtab; (void)strtab; reloc_addr = (unsigned long *)(intptr_t)(tpnt->loadaddr + (unsigned long)rpnt->r_offset); reloc_type = ELF_R_TYPE(rpnt->r_info); #if defined (__SUPPORT_LD_DEBUG__) old_val = *reloc_addr; #endif switch (reloc_type) { case R_386_NONE: break; case R_386_JMP_SLOT: *reloc_addr += (unsigned long)tpnt->loadaddr; break; default: return -1; } #if defined (__SUPPORT_LD_DEBUG__) if (_dl_debug_reloc && _dl_debug_detail) _dl_dprintf(_dl_debug_file, "\n\tpatched: %x ==> %x @ %x\n", old_val, *reloc_addr, reloc_addr); #endif return 0; } void _dl_parse_lazy_relocation_information(struct dyn_elf *rpnt, unsigned long rel_addr, unsigned long rel_size) { (void)_dl_parse(rpnt->dyn, NULL, rel_addr, rel_size, _dl_do_lazy_reloc); } int _dl_parse_relocation_information(struct dyn_elf *rpnt, struct r_scope_elem *scope, unsigned long rel_addr, unsigned long rel_size) { return _dl_parse(rpnt->dyn, scope, rel_addr, rel_size, _dl_do_reloc); } |