ldso/ldso/avr32/elfinterp.c

   1 /*
   2  * AVR32 ELF shared library loader suppport
   3  *
   4  * Copyright (C) 2004-2006 Atmel Corporation
   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 unsigned long _dl_linux_resolver(unsigned long got_offset, unsigned long *got)
  31 {
  32         /*
  33          * AVR32 currently does not do lazy relocation.
  34          */
  35 #if 0
  36         struct elf_resolve *tpnt = (struct elf_resolve *)got[1];
  37         Elf32_Sym *sym;
  38         unsigned long local_gotno;
  39         unsigned long gotsym;
  40         unsigned long new_addr;
  41         char *strtab, *symname;
  42         unsigned long *entry;
  43         unsigned long sym_index = got_offset / 4;
  44
  45         local_gotno = tpnt->dynamic_info[DT_AVR32_LOCAL_GOTNO];
  46         gotsym = tpnt->dynamic_info[DT_AVR32_GOTSYM];
  47
  48         sym = ((Elf32_Sym *)(tpnt->dynamic_info[DT_SYMTAB] + tpnt->loadaddr))
  49                 + sym_index;
  50         strtab = (char *)(tpnt->dynamic_info[DT_STRTAB] + tpnt->loadaddr);
  51         symname = strtab + sym->st_name;
  52
  53         new_addr = (unsigned long) _dl_find_hash(symname,
  54                                                  tpnt->symbol_scope, tpnt, ELF_RTYPE_CLASS_PLT, NULL);
  55
  56         entry = (unsigned long *)(got + local_gotno + sym_index - gotsym);
  57         *entry = new_addr;
  58
  59         return new_addr;
  60 #endif
  61         return 0;
  62 }
  63
  64 static int
  65 _dl_parse(struct elf_resolve *tpnt, struct dyn_elf *scope,
  66           unsigned long rel_addr, unsigned long rel_size,
  67           int (*reloc_func)(struct elf_resolve *tpnt, struct dyn_elf *scope,
  68                             Elf32_Rela *rpnt, Elf32_Sym *symtab, char *strtab))
  69 {
  70         Elf32_Sym *symtab;
  71         Elf32_Rela *rpnt;
  72         char *strtab;
  73         int i;
  74
  75         rpnt = (Elf32_Rela *)rel_addr;
  76         rel_size /= sizeof(Elf32_Rela);
  77         symtab = (Elf32_Sym *)tpnt->dynamic_info[DT_SYMTAB];
  78         strtab = (char *)tpnt->dynamic_info[DT_STRTAB];
  79
  80         for (i = 0; i < rel_size; i++, rpnt++) {
  81                 int symtab_index, res;
  82
  83                 symtab_index = ELF32_R_SYM(rpnt->r_info);
  84
  85                 debug_sym(symtab, strtab, symtab_index);
  86                 debug_reloc(symtab, strtab, rpnt);
  87
  88                 res = reloc_func(tpnt, scope, rpnt, symtab, strtab);
  89
  90                 if (res == 0)
  91                         continue;
  92
  93                 _dl_dprintf(2, "\n%s: ", _dl_progname);
  94
  95                 if (symtab_index)
  96                         _dl_dprintf(2, "symbol '%s': ",
  97                                     strtab + symtab[symtab_index].st_name);
  98
  99                 if (res < 0) {
 100                         int reloc_type = ELF32_R_TYPE(rpnt->r_info);
 101 #if defined(__SUPPORT_LD_DEBUG__)
 102                         _dl_dprintf(2, "can't handle reloc type %s\n",
 103                                     _dl_reltypes(reloc_type));
 104 #else
 105                         _dl_dprintf(2, "can't handle reloc type %x\n",
 106                                     reloc_type);
 107 #endif
 108                         _dl_exit(-res);
 109                 } else {
 110                         _dl_dprintf(2, "can't resolve symbol\n");
 111                         return res;
 112                 }
 113         }
 114
 115         return 0;
 116 }
 117
 118 static int _dl_do_reloc(struct elf_resolve *tpnt, struct dyn_elf *scope,
 119                         Elf32_Rela *rpnt, Elf32_Sym *symtab, char *strtab)
 120 {
 121         int reloc_type;
 122         int symtab_index;
 123         char *symname;
 124         unsigned long *reloc_addr;
 125         unsigned long symbol_addr;
 126 #if defined(__SUPPORT_LD_DEBUG__)
 127         unsigned long old_val;
 128 #endif
 129         struct symbol_ref sym_ref;
 130
 131         reloc_addr = (unsigned long *)(tpnt->loadaddr + rpnt->r_offset);
 132         reloc_type = ELF32_R_TYPE(rpnt->r_info);
 133         symtab_index = ELF32_R_SYM(rpnt->r_info);
 134         symbol_addr = 0;
 135         sym_ref.sym = &symtab[symtab_index];
 136         sym_ref.tpnt = NULL;
 137         symname = strtab + symtab[symtab_index].st_name;
 138
 139         if (symtab_index) {
 140                 symbol_addr = (unsigned long)
 141                         _dl_find_hash(symname, scope, tpnt,
 142                                       elf_machine_type_class(reloc_type), &sym_ref);
 143
 144                 /* Allow undefined references to weak symbols */
 145                 if (!symbol_addr &&
 146                     ELF32_ST_BIND(symtab[symtab_index].st_info) != STB_WEAK) {
 147                         _dl_dprintf(2, "%s: can't resolve symbol '%s'\n",
 148                                     _dl_progname, symname);
 149                         return 0;
 150                 }
 151         }
 152
 153 #if defined(__SUPPORT_LD_DEBUG__)
 154         old_val = *reloc_addr;
 155 #endif
 156         switch (reloc_type) {
 157         case R_AVR32_NONE:
 158                 break;
 159         case R_AVR32_GLOB_DAT:
 160         case R_AVR32_JMP_SLOT:
 161                 *reloc_addr = symbol_addr + rpnt->r_addend;
 162                 break;
 163         case R_AVR32_RELATIVE:
 164                 *reloc_addr = (unsigned long)tpnt->loadaddr
 165                         + rpnt->r_addend;
 166                 break;
 167         default:
 168                 return -1;
 169         }
 170
 171 #if defined(__SUPPORT_LD_DEBUG__)
 172         if (_dl_debug_reloc && _dl_debug_detail)
 173                 _dl_dprintf(_dl_debug_file, "\tpatched: %x ==> %x @ %x\n",
 174                             old_val, *reloc_addr);
 175 #endif
 176
 177         return 0;
 178 }
 179
 180 void _dl_parse_lazy_relocation_information(struct dyn_elf *rpnt,
 181                                            unsigned long rel_addr,
 182                                            unsigned long rel_size)
 183 {
 184         /* TODO: Might want to support this in order to get faster
 185          * startup times... */
 186 }
 187
 188 int _dl_parse_relocation_information(struct dyn_elf *rpnt,
 189                                      unsigned long rel_addr,
 190                                      unsigned long rel_size)
 191 {
 192         return _dl_parse(rpnt->dyn, rpnt->dyn->symbol_scope, rel_addr, rel_size,
 193                          _dl_do_reloc);
 194 }