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
  34 #define OFFSET_GP_GOT 0x7ff0
  35
  36 unsigned long __dl_runtime_resolve(unsigned long sym_index,
  37         unsigned long old_gpreg)
  38 {
  39         unsigned long *got = (unsigned long *) (old_gpreg - OFFSET_GP_GOT);
  40         struct elf_resolve *tpnt = (struct elf_resolve *) got[1];
  41         ElfW(Sym) *sym;
  42         char *strtab;
  43         unsigned long local_gotno;
  44         unsigned long gotsym;
  45         unsigned long new_addr;
  46         unsigned long instr_addr;
  47         char **got_addr;
  48         char *symname;
  49
  50         gotsym = tpnt->dynamic_info[DT_MIPS_GOTSYM_IDX];
  51         local_gotno = tpnt->dynamic_info[DT_MIPS_LOCAL_GOTNO_IDX];
  52
  53         sym = ((ElfW(Sym) *) tpnt->dynamic_info[DT_SYMTAB]) + sym_index;
  54         strtab = (char *) tpnt->dynamic_info[DT_STRTAB];
  55         symname = strtab + sym->st_name;
  56
  57         new_addr = (unsigned long) _dl_find_hash(symname,
  58                         tpnt->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT);
  59         if (unlikely(!new_addr)) {
  60                 _dl_dprintf (2, "%s: can't resolve symbol '%s'\n",
  61                                 _dl_progname, symname);
  62                 _dl_exit (1);
  63         }
  64
  65         /* Address of jump instruction to fix up */
  66         instr_addr = (unsigned long) (got + local_gotno + sym_index - gotsym);
  67         got_addr = (char **) instr_addr;
  68
  69 #if defined (__SUPPORT_LD_DEBUG__)
  70         if (_dl_debug_bindings)
  71         {
  72                 _dl_dprintf(_dl_debug_file, "\nresolve function: %s", symname);
  73                 if (_dl_debug_detail) _dl_dprintf(_dl_debug_file,
  74                                 "\n\tpatched %x ==> %x @ %x\n", *got_addr, new_addr, got_addr);
  75         }
  76         if (!_dl_debug_nofixups) {
  77                 *got_addr = (char*)new_addr;
  78         }
  79 #else
  80         *got_addr = (char*)new_addr;
  81 #endif
  82
  83         return new_addr;
  84 }
  85
  86 void _dl_parse_lazy_relocation_information(struct dyn_elf *rpnt,
  87         unsigned long rel_addr, unsigned long rel_size)
  88 {
  89         /* Nothing to do */
  90         return;
  91 }
  92
  93 int _dl_parse_relocation_information(struct dyn_elf *xpnt,
  94         unsigned long rel_addr, unsigned long rel_size)
  95 {
  96         ElfW(Sym) *symtab;
  97         ElfW(Rel) *rpnt;
  98         char *strtab;
  99         unsigned long i;
 100         unsigned long *got;
 101         unsigned long *reloc_addr=NULL;
 102         unsigned long symbol_addr;
 103         int reloc_type, symtab_index;
 104         struct elf_resolve *tpnt = xpnt->dyn;
 105 #if defined (__SUPPORT_LD_DEBUG__)
 106         unsigned long old_val=0;
 107 #endif
 108
 109         /* Now parse the relocation information */
 110         rel_size = rel_size / sizeof(ElfW(Rel));
 111         rpnt = (ElfW(Rel) *) rel_addr;
 112
 113         symtab = (ElfW(Sym) *) tpnt->dynamic_info[DT_SYMTAB];
 114         strtab = (char *) tpnt->dynamic_info[DT_STRTAB];
 115         got = (unsigned long *) tpnt->dynamic_info[DT_PLTGOT];
 116
 117         for (i = 0; i < rel_size; i++, rpnt++) {
 118                 reloc_addr = (unsigned long *) (tpnt->loadaddr +
 119                         (unsigned long) rpnt->r_offset);
 120                 reloc_type = ELF_R_TYPE(rpnt->r_info);
 121                 symtab_index = ELF_R_SYM(rpnt->r_info);
 122                 symbol_addr = 0;
 123
 124                 debug_sym(symtab,strtab,symtab_index);
 125                 debug_reloc(symtab,strtab,rpnt);
 126 #if defined (__SUPPORT_LD_DEBUG__)
 127                 if (reloc_addr)
 128                         old_val = *reloc_addr;
 129 #endif
 130
 131                 switch (reloc_type) {
 132 #if _MIPS_SIM == _MIPS_SIM_ABI64
 133                 case (R_MIPS_64 << 8) | R_MIPS_REL32:
 134 #else   /* O32 || N32 */
 135                 case R_MIPS_REL32:
 136 #endif  /* O32 || N32 */
 137                         if (symtab_index) {
 138                                 if (symtab_index < tpnt->dynamic_info[DT_MIPS_GOTSYM_IDX])
 139                                         *reloc_addr +=
 140                                                 symtab[symtab_index].st_value +
 141                                                 (unsigned long) tpnt->loadaddr;
 142                                 else {
 143                                         *reloc_addr += got[symtab_index + tpnt->dynamic_info[DT_MIPS_LOCAL_GOTNO_IDX] -
 144                                                 tpnt->dynamic_info[DT_MIPS_GOTSYM_IDX]];
 145                                 }
 146                         }
 147                         else {
 148                                 *reloc_addr += (unsigned long) tpnt->loadaddr;
 149                         }
 150                         break;
 151                 case R_MIPS_NONE:
 152                         break;
 153                 default:
 154                         {
 155                                 _dl_dprintf(2, "\n%s: ",_dl_progname);
 156
 157                                 if (symtab_index)
 158                                         _dl_dprintf(2, "symbol '%s': ", strtab + symtab[symtab_index].st_name);
 159
 160 #if defined (__SUPPORT_LD_DEBUG__)
 161                                 _dl_dprintf(2, "can't handle reloc type %s\n ", _dl_reltypes(reloc_type));
 162 #else
 163                                 _dl_dprintf(2, "can't handle reloc type %x\n", reloc_type);
 164 #endif
 165                                 _dl_exit(1);
 166                         }
 167                 }
 168
 169         }
 170 #if defined (__SUPPORT_LD_DEBUG__)
 171         if (_dl_debug_reloc && _dl_debug_detail && reloc_addr)
 172                 _dl_dprintf(_dl_debug_file, "\tpatched: %x ==> %x @ %x\n", old_val, *reloc_addr, reloc_addr);
 173 #endif
 174
 175         return 0;
 176 }
 177
 178 /* Relocate the global GOT entries for the object */
 179 void _dl_perform_mips_global_got_relocations(struct elf_resolve *tpnt, int lazy)
 180 {
 181         ElfW(Sym) *sym;
 182         char *strtab;
 183         unsigned long i, tmp_lazy;
 184         unsigned long *got_entry;
 185
 186         for (; tpnt ; tpnt = tpnt->next) {
 187
 188                 /* We don't touch the dynamic linker */
 189                 if (tpnt->libtype == program_interpreter)
 190                         continue;
 191
 192                 /* Setup the loop variables */
 193                 got_entry = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT])
 194                         + tpnt->dynamic_info[DT_MIPS_LOCAL_GOTNO_IDX];
 195                 sym = (ElfW(Sym) *) tpnt->dynamic_info[DT_SYMTAB] + tpnt->dynamic_info[DT_MIPS_GOTSYM_IDX];
 196                 strtab = (char *) tpnt->dynamic_info[DT_STRTAB];
 197                 i = tpnt->dynamic_info[DT_MIPS_SYMTABNO_IDX] - tpnt->dynamic_info[DT_MIPS_GOTSYM_IDX];
 198
 199 #if defined (__SUPPORT_LD_DEBUG__)
 200                 if (_dl_debug_reloc)
 201                         _dl_dprintf(2, "_dl_perform_mips_global_got_relocations for '%s'\n", tpnt->libname);
 202 #endif
 203                 tmp_lazy = lazy && !tpnt->dynamic_info[DT_BIND_NOW];
 204                 /* Relocate the global GOT entries for the object */
 205                 while (i--) {
 206                         if (sym->st_shndx == SHN_UNDEF) {
 207                                 if (ELF_ST_TYPE(sym->st_info) == STT_FUNC && sym->st_value && tmp_lazy) {
 208                                         *got_entry = sym->st_value + (unsigned long) tpnt->loadaddr;
 209                                 }
 210                                 else {
 211                                         *got_entry = (unsigned long) _dl_find_hash(strtab +
 212                                                 sym->st_name, tpnt->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT);
 213                                 }
 214                         }
 215                         else if (sym->st_shndx == SHN_COMMON) {
 216                                 *got_entry = (unsigned long) _dl_find_hash(strtab +
 217                                         sym->st_name, tpnt->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT);
 218                         }
 219                         else if (ELF_ST_TYPE(sym->st_info) == STT_FUNC &&
 220                                 *got_entry != sym->st_value && tmp_lazy) {
 221                                 *got_entry += (unsigned long) tpnt->loadaddr;
 222                         }
 223                         else if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) {
 224                                 if (sym->st_other == 0)
 225                                         *got_entry += (unsigned long) tpnt->loadaddr;
 226                         }
 227                         else {
 228                                 *got_entry = (unsigned long) _dl_find_hash(strtab +
 229                                         sym->st_name, tpnt->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT);
 230                         }
 231
 232                         got_entry++;
 233                         sym++;
 234                 }
 235         }
 236 }
 237