ldso/ldso/mips/elfinterp.c

   1 /* vi: set sw=4 ts=4: */
   2 /* mips/mipsel ELF shared library loader suppport
   3  *
   4    Copyright (C) 2002, Steven J. Hill (sjhill@realitydiluted.com)
   5  *
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. The name of the above contributors may not be
  14  *    used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #include "ldso.h"
  31
  32 extern int _dl_runtime_resolve(void);
  33 extern int _dl_runtime_pltresolve(void);
  34
  35 #define OFFSET_GP_GOT 0x7ff0
  36
  37 unsigned long __dl_runtime_resolve(unsigned long sym_index,
  38         unsigned long old_gpreg)
  39 {
  40         unsigned long *got = (unsigned long *) (old_gpreg - OFFSET_GP_GOT);
  41         struct elf_resolve *tpnt = (struct elf_resolve *) got[1];
  42         ElfW(Sym) *sym;
  43         char *strtab;
  44         unsigned long local_gotno;
  45         unsigned long gotsym;
  46         unsigned long new_addr;
  47         unsigned long instr_addr;
  48         char **got_addr;
  49         char *symname;
  50
  51         gotsym = tpnt->dynamic_info[DT_MIPS_GOTSYM_IDX];
  52         local_gotno = tpnt->dynamic_info[DT_MIPS_LOCAL_GOTNO_IDX];
  53
  54         sym = ((ElfW(Sym) *) tpnt->dynamic_info[DT_SYMTAB]) + sym_index;
  55         strtab = (char *) tpnt->dynamic_info[DT_STRTAB];
  56         symname = strtab + sym->st_name;
  57
  58         new_addr = (unsigned long) _dl_find_hash(symname,
  59                         &_dl_loaded_modules->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT, NULL);
  60         if (unlikely(!new_addr)) {
  61                 _dl_dprintf (2, "%s: can't resolve symbol '%s'\n",
  62                                 _dl_progname, symname);
  63                 _dl_exit (1);
  64         }
  65
  66         /* Address of jump instruction to fix up */
  67         instr_addr = (unsigned long) (got + local_gotno + sym_index - gotsym);
  68         got_addr = (char **) instr_addr;
  69
  70 #if defined (__SUPPORT_LD_DEBUG__)
  71         if (_dl_debug_bindings)
  72         {
  73                 _dl_dprintf(_dl_debug_file, "\nresolve function: %s", symname);
  74                 if (_dl_debug_detail) _dl_dprintf(_dl_debug_file,
  75                                 "\n\tpatched %x ==> %x @ %x\n", *got_addr, new_addr, got_addr);
  76         }
  77         if (!_dl_debug_nofixups) {
  78                 *got_addr = (char*)new_addr;
  79         }
  80 #else
  81         *got_addr = (char*)new_addr;
  82 #endif
  83
  84         return new_addr;
  85 }
  86
  87 unsigned long
  88 __dl_runtime_pltresolve(struct elf_resolve *tpnt, int reloc_entry)
  89 {
  90         ELF_RELOC *this_reloc;
  91         char *strtab;
  92         ElfW(Sym) *symtab;
  93         int symtab_index;
  94         char *rel_addr;
  95         char *new_addr;
  96         char **got_addr;
  97         unsigned long instr_addr;
  98         char *symname;
  99
 100         rel_addr = (char *)tpnt->dynamic_info[DT_JMPREL];
 101         this_reloc = (ELF_RELOC *)(intptr_t)(rel_addr + reloc_entry);
 102         symtab_index = ELF_R_SYM(this_reloc->r_info);
 103
 104         symtab = (ElfW(Sym) *)(intptr_t)tpnt->dynamic_info[DT_SYMTAB];
 105         strtab = (char *)tpnt->dynamic_info[DT_STRTAB];
 106         symname = strtab + symtab[symtab_index].st_name;
 107
 108         /* Address of the jump instruction to fix up. */
 109         instr_addr = ((unsigned long)this_reloc->r_offset +
 110                       (unsigned long)tpnt->loadaddr);
 111         got_addr = (char **)instr_addr;
 112
 113         /* Get the address of the GOT entry. */
 114         new_addr = _dl_find_hash(symname, &_dl_loaded_modules->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT, NULL);
 115         if (unlikely(!new_addr)) {
 116                 _dl_dprintf(2, "%s: can't resolve symbol '%s' in lib '%s'.\n", _dl_progname, symname, tpnt->libname);
 117                 _dl_exit(1);
 118         }
 119
 120 #if defined (__SUPPORT_LD_DEBUG__)
 121         if ((unsigned long)got_addr < 0x40000000) {
 122                 if (_dl_debug_bindings) {
 123                         _dl_dprintf(_dl_debug_file, "\nresolve function: %s", symname);
 124                         if (_dl_debug_detail)
 125                                 _dl_dprintf(_dl_debug_file,
 126                                             "\n\tpatched: %x ==> %x @ %x",
 127                                             *got_addr, new_addr, got_addr);
 128                 }
 129         }
 130         if (!_dl_debug_nofixups) {
 131                 *got_addr = new_addr;
 132         }
 133 #else
 134         *got_addr = new_addr;
 135 #endif
 136
 137         return (unsigned long)new_addr;
 138 }
 139
 140 void _dl_parse_lazy_relocation_information(struct dyn_elf *rpnt,
 141         unsigned long rel_addr, unsigned long rel_size)
 142 {
 143         /* Nothing to do */
 144         return;
 145 }
 146
 147 int _dl_parse_relocation_information(struct dyn_elf *xpnt,
 148         struct r_scope_elem *scope, unsigned long rel_addr, unsigned long rel_size)
 149 {
 150         ElfW(Sym) *symtab;
 151         ELF_RELOC *rpnt;
 152         char *strtab;
 153         unsigned long i;
 154         unsigned long *got;
 155         unsigned long *reloc_addr=NULL;
 156         unsigned long symbol_addr;
 157         int reloc_type, symtab_index;
 158         struct elf_resolve *tpnt = xpnt->dyn;
 159         char *symname = NULL;
 160 #if defined (__SUPPORT_LD_DEBUG__)
 161         unsigned long old_val=0;
 162 #endif
 163
 164         struct symbol_ref sym_ref;
 165         /* Now parse the relocation information */
 166         rel_size = rel_size / sizeof(ElfW(Rel));
 167         rpnt = (ELF_RELOC *) rel_addr;
 168
 169         symtab = (ElfW(Sym) *) tpnt->dynamic_info[DT_SYMTAB];
 170         strtab = (char *) tpnt->dynamic_info[DT_STRTAB];
 171         got = (unsigned long *) tpnt->dynamic_info[DT_PLTGOT];
 172
 173
 174         for (i = 0; i < rel_size; i++, rpnt++) {
 175                 reloc_addr = (unsigned long *) (tpnt->loadaddr +
 176                         (unsigned long) rpnt->r_offset);
 177                 reloc_type = ELF_R_TYPE(rpnt->r_info);
 178                 symtab_index = ELF_R_SYM(rpnt->r_info);
 179                 symbol_addr = 0;
 180
 181                 debug_sym(symtab,strtab,symtab_index);
 182                 debug_reloc(symtab,strtab,rpnt);
 183                 symname = strtab + symtab[symtab_index].st_name;
 184 #if defined (__SUPPORT_LD_DEBUG__)
 185                 if (reloc_addr)
 186                         old_val = *reloc_addr;
 187 #endif
 188
 189                 if (reloc_type == R_MIPS_JUMP_SLOT || reloc_type == R_MIPS_COPY) {
 190                         sym_ref.tpnt = NULL;
 191                         sym_ref.sym = &symtab[symtab_index];
 192                         symbol_addr = (unsigned long)_dl_find_hash(symname,
 193                                                                    scope,
 194                                                                    tpnt,
 195                                                                    elf_machine_type_class(reloc_type), &sym_ref);
 196                         if (unlikely(!symbol_addr && ELF_ST_BIND(symtab[symtab_index].st_info) != STB_WEAK))
 197                                 return 1;
 198                         if (_dl_trace_prelink) {
 199                                 _dl_debug_lookup (symname, tpnt, &symtab[symtab_index],
 200                                                         &sym_ref, elf_machine_type_class(reloc_type));
 201                         }
 202                 }
 203                 if (!symtab_index) {
 204                         /* Relocs against STN_UNDEF are usually treated as using a
 205                         * symbol value of zero, and using the module containing the
 206                         * reloc itself.
 207                         */
 208                         symbol_addr = symtab[symtab_index].st_value;
 209                 }
 210
 211                 switch (reloc_type) {
 212 #if defined USE_TLS && USE_TLS
 213 # if _MIPS_SIM == _MIPS_SIM_ABI64
 214                 case R_MIPS_TLS_DTPMOD64:
 215                 case R_MIPS_TLS_DTPREL64:
 216                 case R_MIPS_TLS_TPREL64:
 217 # else
 218                 case R_MIPS_TLS_DTPMOD32:
 219                 case R_MIPS_TLS_DTPREL32:
 220                 case R_MIPS_TLS_TPREL32:
 221 # endif
 222                         {
 223                                 struct elf_resolve *tls_tpnt = NULL;
 224                                 sym_ref.sym =  &symtab[symtab_index];
 225                                 sym_ref.tpnt =  NULL;
 226
 227                                 if (ELF_ST_BIND(symtab[symtab_index].st_info) != STB_LOCAL) {
 228                                         symbol_addr = (unsigned long) _dl_find_hash(symname, scope,
 229                                                 tpnt, elf_machine_type_class(reloc_type), &sym_ref);
 230                                         tls_tpnt = sym_ref.tpnt;
 231                                 }
 232                             /* In case of a TLS reloc, tls_tpnt NULL means we have an 'anonymous'
 233                                symbol.  This is the case for a static tls variable, so the lookup
 234                                module is just that one is referencing the tls variable. */
 235                             if (!tls_tpnt)
 236                                 tls_tpnt = tpnt;
 237
 238                                 switch (reloc_type) {
 239                                         case R_MIPS_TLS_DTPMOD64:
 240                                         case R_MIPS_TLS_DTPMOD32:
 241                                                 if (tls_tpnt)
 242                                                         *(ElfW(Word) *)reloc_addr = tls_tpnt->l_tls_modid;
 243 #ifdef __SUPPORT_LD_DEBUG__
 244                                                 _dl_dprintf(2, "TLS_DTPMOD : %s, %d, %d\n",
 245                                                         symname, old_val, *((unsigned int *)reloc_addr));
 246 #endif
 247                                                 break;
 248
 249                                         case R_MIPS_TLS_DTPREL64:
 250                                         case R_MIPS_TLS_DTPREL32:
 251                                                 *(ElfW(Word) *)reloc_addr +=
 252                                                         TLS_DTPREL_VALUE (symbol_addr);
 253 #ifdef __SUPPORT_LD_DEBUG__
 254                                                 _dl_dprintf(2, "TLS_DTPREL : %s, %x, %x\n",
 255                                                         symname, old_val, *((unsigned int *)reloc_addr));
 256 #endif
 257                                                 break;
 258
 259                                         case R_MIPS_TLS_TPREL32:
 260                                         case R_MIPS_TLS_TPREL64:
 261                                                 CHECK_STATIC_TLS((struct link_map *)tls_tpnt);
 262                                                 *(ElfW(Addr) *)reloc_addr +=
 263                                                         TLS_TPREL_VALUE (tls_tpnt, symbol_addr);
 264 #ifdef __SUPPORT_LD_DEBUG__
 265                                                 _dl_dprintf(2, "TLS_TPREL  : %s, %x, %x\n",
 266                                                         symname, old_val, *((unsigned long *)reloc_addr));
 267 #endif
 268                                                 break;
 269                                 }
 270
 271                                 break;
 272                         }
 273 #endif /* USE_TLS */
 274 #if _MIPS_SIM == _MIPS_SIM_ABI64
 275                 case (R_MIPS_64 << 8) | R_MIPS_REL32:
 276 #else   /* O32 || N32 */
 277                 case R_MIPS_REL32:
 278 #endif  /* O32 || N32 */
 279                         if (symtab_index) {
 280                                 if (symtab_index < tpnt->dynamic_info[DT_MIPS_GOTSYM_IDX])
 281                                         *reloc_addr +=
 282                                                 symtab[symtab_index].st_value +
 283                                                 (unsigned long) tpnt->loadaddr;
 284                                 else {
 285                                         *reloc_addr += got[symtab_index + tpnt->dynamic_info[DT_MIPS_LOCAL_GOTNO_IDX] -
 286                                                 tpnt->dynamic_info[DT_MIPS_GOTSYM_IDX]];
 287                                 }
 288                         }
 289                         else {
 290                                 *reloc_addr += (unsigned long) tpnt->loadaddr;
 291                         }
 292                         break;
 293                 case R_MIPS_JUMP_SLOT:
 294                         *reloc_addr = symbol_addr;
 295                         break;
 296                 case R_MIPS_COPY:
 297                         if (symbol_addr) {
 298 #if defined (__SUPPORT_LD_DEBUG__)
 299                                 if (_dl_debug_move)
 300                                         _dl_dprintf(_dl_debug_file,
 301                                                     "\n%s move %d bytes from %x to %x",
 302                                                     symname, symtab[symtab_index].st_size,
 303                                                     symbol_addr, reloc_addr);
 304 #endif
 305
 306                                 _dl_memcpy((char *)reloc_addr,
 307                                            (char *)symbol_addr,
 308                                            symtab[symtab_index].st_size);
 309                         }
 310                         break;
 311                 case R_MIPS_NONE:
 312                         break;
 313                 default:
 314                         {
 315                                 _dl_dprintf(2, "\n%s: ",_dl_progname);
 316
 317                                 if (symtab_index)
 318                                         _dl_dprintf(2, "symbol '%s': ", symname);
 319
 320 #if defined (__SUPPORT_LD_DEBUG__)
 321                                 _dl_dprintf(2, "can't handle reloc type '%s' in lib '%s'\n", _dl_reltypes(reloc_type), tpnt->libname);
 322 #else
 323                                 _dl_dprintf(2, "can't handle reloc type %x in lib '%s'\n", reloc_type, tpnt->libname);
 324 #endif
 325                                 _dl_exit(1);
 326                         }
 327                 }
 328         }
 329 #if defined (__SUPPORT_LD_DEBUG__)
 330         if (_dl_debug_reloc && _dl_debug_detail && reloc_addr)
 331                 _dl_dprintf(_dl_debug_file, "\tpatched: %x ==> %x @ %x\n", old_val, *reloc_addr, reloc_addr);
 332 #endif
 333
 334         return 0;
 335 }
 336
 337 /* Relocate the global GOT entries for the object */
 338 void _dl_perform_mips_global_got_relocations(struct elf_resolve *tpnt, int lazy)
 339 {
 340         ElfW(Sym) *sym;
 341         char *strtab;
 342         unsigned long i, tmp_lazy;
 343         unsigned long *got_entry;
 344
 345         for (; tpnt ; tpnt = tpnt->next) {
 346
 347                 /* We don't touch the dynamic linker */
 348                 if (tpnt->libtype == program_interpreter)
 349                         continue;
 350
 351                 /* Setup the loop variables */
 352                 got_entry = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT])
 353                         + tpnt->dynamic_info[DT_MIPS_LOCAL_GOTNO_IDX];
 354                 sym = (ElfW(Sym) *) tpnt->dynamic_info[DT_SYMTAB] + tpnt->dynamic_info[DT_MIPS_GOTSYM_IDX];
 355                 strtab = (char *) tpnt->dynamic_info[DT_STRTAB];
 356                 i = tpnt->dynamic_info[DT_MIPS_SYMTABNO_IDX] - tpnt->dynamic_info[DT_MIPS_GOTSYM_IDX];
 357
 358 #if defined (__SUPPORT_LD_DEBUG__)
 359                 if (_dl_debug_reloc)
 360                         _dl_dprintf(2, "_dl_perform_mips_global_got_relocations for '%s'\n", tpnt->libname);
 361 #endif
 362                 tmp_lazy = lazy && !tpnt->dynamic_info[DT_BIND_NOW];
 363                 /* Relocate the global GOT entries for the object */
 364                 while (i--) {
 365                         if (sym->st_shndx == SHN_UNDEF) {
 366                                 if (ELF_ST_TYPE(sym->st_info) == STT_FUNC && sym->st_value && tmp_lazy) {
 367                                         *got_entry = sym->st_value + (unsigned long) tpnt->loadaddr;
 368                                 }
 369                                 else {
 370                                         *got_entry = (unsigned long) _dl_find_hash(strtab +
 371                                                 sym->st_name, &_dl_loaded_modules->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT, NULL);
 372                                 }
 373                         }
 374                         else if (sym->st_shndx == SHN_COMMON) {
 375                                 *got_entry = (unsigned long) _dl_find_hash(strtab +
 376                                         sym->st_name, &_dl_loaded_modules->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT, NULL);
 377                         }
 378                         else if (ELF_ST_TYPE(sym->st_info) == STT_FUNC &&
 379                                 *got_entry != sym->st_value && tmp_lazy) {
 380                                 *got_entry += (unsigned long) tpnt->loadaddr;
 381                         }
 382                         else if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) {
 383                                 if (sym->st_other == 0)
 384                                         *got_entry += (unsigned long) tpnt->loadaddr;
 385                         }
 386                         else {
 387                                 struct symbol_ref sym_ref;
 388                                 sym_ref.sym = sym;
 389                                 sym_ref.tpnt = NULL;
 390                                 *got_entry = (unsigned long) _dl_find_hash(strtab +
 391                                         sym->st_name, &_dl_loaded_modules->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT, &sym_ref);
 392                         }
 393
 394                         got_entry++;
 395                         sym++;
 396                 }
 397         }
 398 }
 399