libexec/ld.elf_so/arch/m68k/mdreloc.c

   1 /*      $NetBSD: mdreloc.c,v 1.27 2010/08/06 16:33:18 joerg Exp $       */
   2
   3 #include <sys/cdefs.h>
   4 #ifndef lint
   5 __RCSID("$NetBSD: mdreloc.c,v 1.27 2010/08/06 16:33:18 joerg Exp $");
   6 #endif /* not lint */
   7
   8 #include <sys/cdefs.h>
   9 #ifndef lint
  10 __RCSID("$NetBSD: mdreloc.c,v 1.27 2010/08/06 16:33:18 joerg Exp $");
  11 #endif /* not lint */
  12
  13 #include <sys/types.h>
  14
  15 #include "debug.h"
  16 #include "rtld.h"
  17
  18 void _rtld_bind_start(void);
  19 void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
  20 caddr_t _rtld_bind(const Obj_Entry *, Elf_Word);
  21 static inline int _rtld_relocate_plt_object(const Obj_Entry *,
  22     const Elf_Rela *, Elf_Addr *);
  23
  24
  25 void
  26 _rtld_setup_pltgot(const Obj_Entry *obj)
  27 {
  28         obj->pltgot[1] = (Elf_Addr) obj;
  29         obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start;
  30 }
  31
  32 void
  33 _rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
  34 {
  35         const Elf_Rela *rela = 0, *relalim;
  36         Elf_Addr relasz = 0;
  37         Elf_Addr *where;
  38
  39         for (; dynp->d_tag != DT_NULL; dynp++) {
  40                 switch (dynp->d_tag) {
  41                 case DT_RELA:
  42                         rela = (const Elf_Rela *)(relocbase + dynp->d_un.d_ptr);
  43                         break;
  44                 case DT_RELASZ:
  45                         relasz = dynp->d_un.d_val;
  46                         break;
  47                 }
  48         }
  49         relalim = (const Elf_Rela *)((const uint8_t *)rela + relasz);
  50         for (; rela < relalim; rela++) {
  51                 where = (Elf_Addr *)(relocbase + rela->r_offset);
  52                 *where += (Elf_Addr)relocbase;
  53         }
  54 }
  55
  56 int
  57 _rtld_relocate_nonplt_objects(Obj_Entry *obj)
  58 {
  59         const Elf_Rela *rela;
  60
  61         for (rela = obj->rela; rela < obj->relalim; rela++) {
  62                 Elf_Addr        *where;
  63                 const Elf_Sym   *def;
  64                 const Obj_Entry *defobj;
  65                 Elf_Addr         tmp;
  66                 unsigned long    symnum;
  67
  68                 where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
  69                 symnum = ELF_R_SYM(rela->r_info);
  70
  71                 switch (ELF_R_TYPE(rela->r_info)) {
  72                 case R_TYPE(NONE):
  73                         break;
  74
  75 #if 1 /* XXX should not occur */
  76                 case R_TYPE(PC32):
  77                         def = _rtld_find_symdef(symnum, obj, &defobj, false);
  78                         if (def == NULL)
  79                                 return -1;
  80
  81                         tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
  82                             rela->r_addend) - (Elf_Addr)where;
  83                         if (*where != tmp)
  84                                 *where = tmp;
  85                         rdbg(("PC32 %s in %s --> %p in %s",
  86                             obj->strtab + obj->symtab[symnum].st_name,
  87                             obj->path, (void *)*where, defobj->path));
  88                         break;
  89
  90                 case R_TYPE(GOT32):
  91 #endif
  92                 case R_TYPE(32):
  93                 case R_TYPE(GLOB_DAT):
  94                         def = _rtld_find_symdef(symnum, obj, &defobj, false);
  95                         if (def == NULL)
  96                                 return -1;
  97
  98                         tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
  99                             rela->r_addend);
 100                         if (*where != tmp)
 101                                 *where = tmp;
 102                         rdbg(("32/GLOB_DAT %s in %s --> %p in %s",
 103                             obj->strtab + obj->symtab[symnum].st_name,
 104                             obj->path, (void *)*where, defobj->path));
 105                         break;
 106
 107                 case R_TYPE(RELATIVE):
 108                         *where += (Elf_Addr)obj->relocbase;
 109                         rdbg(("RELATIVE in %s --> %p", obj->path,
 110                             (void *)*where));
 111                         break;
 112
 113                 case R_TYPE(COPY):
 114                         /*
 115                          * These are deferred until all other relocations have
 116                          * been done.  All we do here is make sure that the
 117                          * COPY relocation is not in a shared library.  They
 118                          * are allowed only in executable files.
 119                          */
 120                         if (obj->isdynamic) {
 121                                 _rtld_error(
 122                         "%s: Unexpected R_COPY relocation in shared library",
 123                                     obj->path);
 124                                 return -1;
 125                         }
 126                         rdbg(("COPY (avoid in main)"));
 127                         break;
 128
 129                 default:
 130                         rdbg(("sym = %lu, type = %lu, offset = %p, "
 131                             "addend = %p, contents = %p, symbol = %s",
 132                             symnum, (u_long)ELF_R_TYPE(rela->r_info),
 133                             (void *)rela->r_offset, (void *)rela->r_addend,
 134                             (void *)*where,
 135                             obj->strtab + obj->symtab[symnum].st_name));
 136                         _rtld_error("%s: Unsupported relocation type %ld "
 137                             "in non-PLT relocations",
 138                             obj->path, (u_long) ELF_R_TYPE(rela->r_info));
 139                         return -1;
 140                 }
 141         }
 142         return 0;
 143 }
 144
 145 int
 146 _rtld_relocate_plt_lazy(const Obj_Entry *obj)
 147 {
 148         const Elf_Rela *rela;
 149
 150         if (!obj->relocbase)
 151                 return 0;
 152
 153         for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) {
 154                 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
 155
 156                 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
 157
 158                 /* Just relocate the GOT slots pointing into the PLT */
 159                 *where += (Elf_Addr)obj->relocbase;
 160                 rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where));
 161         }
 162
 163         return 0;
 164 }
 165
 166 static inline int
 167 _rtld_relocate_plt_object(const Obj_Entry *obj, const Elf_Rela *rela,
 168     Elf_Addr *tp)
 169 {
 170         Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
 171         Elf_Addr new_value;
 172         const Elf_Sym  *def;
 173         const Obj_Entry *defobj;
 174         unsigned long info = rela->r_info;
 175
 176         assert(ELF_R_TYPE(info) == R_TYPE(JMP_SLOT));
 177
 178         def = _rtld_find_plt_symdef(ELF_R_SYM(info), obj, &defobj, tp != NULL);
 179         if (__predict_false(def == NULL))
 180                 return -1;
 181         if (__predict_false(def == &_rtld_sym_zero))
 182                 return 0;
 183
 184         assert(rela->r_addend == 0);
 185         new_value = (Elf_Addr)(defobj->relocbase + def->st_value +
 186             rela->r_addend);
 187         rdbg(("bind now/fixup in %s --> old=%p new=%p",
 188             defobj->strtab + def->st_name, (void *)*where, (void *)new_value));
 189         if (*where != new_value)
 190                 *where = new_value;
 191
 192         if (tp)
 193                 *tp = new_value - rela->r_addend;
 194
 195         return 0;
 196 }
 197
 198 caddr_t
 199 _rtld_bind(const Obj_Entry *obj, Elf_Word reloff)
 200 {
 201         const Elf_Rela *rela = (const Elf_Rela *)((const uint8_t *)obj->pltrela + reloff);
 202         Elf_Addr result;
 203         int err;
 204
 205         result = 0;     /* XXX gcc */
 206
 207         err = _rtld_relocate_plt_object(obj, rela, &result);
 208         if (err)
 209                 _rtld_die();
 210
 211         return (caddr_t)result;
 212 }
 213
 214 int
 215 _rtld_relocate_plt_objects(const Obj_Entry *obj)
 216 {
 217         const Elf_Rela *rela;
 218
 219         for (rela = obj->pltrela; rela < obj->pltrelalim; rela++)
 220                 if (_rtld_relocate_plt_object(obj, rela, NULL) < 0)
 221                         return -1;
 222
 223         return 0;
 224 }