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

   1 /*      $NetBSD: mdreloc.c,v 1.27 2010/08/06 16:33:19 joerg Exp $       */
   2
   3 #include <sys/cdefs.h>
   4 #ifndef lint
   5 __RCSID("$NetBSD: mdreloc.c,v 1.27 2010/08/06 16:33:19 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 16:33:19 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 void
  25 _rtld_setup_pltgot(const Obj_Entry *obj)
  26 {
  27         obj->pltgot[1] = (Elf_Addr) obj;
  28         obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start;
  29 }
  30
  31 void
  32 _rtld_relocate_nonplt_self(Elf_Dyn *dynp, Elf_Addr relocbase)
  33 {
  34         const Elf_Rela *rela = 0, *relalim;
  35         Elf_Addr relasz = 0;
  36         Elf_Addr *where;
  37
  38         for (; dynp->d_tag != DT_NULL; dynp++) {
  39                 switch (dynp->d_tag) {
  40                 case DT_RELA:
  41                         rela = (const Elf_Rela *)(relocbase + dynp->d_un.d_ptr);
  42                         break;
  43                 case DT_RELASZ:
  44                         relasz = dynp->d_un.d_val;
  45                         break;
  46                 }
  47         }
  48         relalim = (const Elf_Rela *)((const uint8_t *)rela + relasz);
  49         for (; rela < relalim; rela++) {
  50                 where = (Elf_Addr *)(relocbase + rela->r_offset);
  51                 *where = (Elf_Addr)(relocbase + rela->r_addend);
  52         }
  53 }
  54
  55 int
  56 _rtld_relocate_nonplt_objects(Obj_Entry *obj)
  57 {
  58         const Elf_Rela *rela;
  59
  60         for (rela = obj->rela; rela < obj->relalim; rela++) {
  61                 Elf_Addr        *where;
  62                 const Elf_Sym   *def;
  63                 const Obj_Entry *defobj;
  64                 Elf_Addr         tmp;
  65                 unsigned long    symnum;
  66
  67                 where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
  68                 symnum = ELF_R_SYM(rela->r_info);
  69
  70                 switch (ELF_R_TYPE(rela->r_info)) {
  71                 case R_TYPE(NONE):
  72                         break;
  73
  74                 case R_TYPE(32):        /* word32 S + A */
  75                 case R_TYPE(GLOB_DAT):  /* word32 S + A */
  76                         def = _rtld_find_symdef(symnum, obj, &defobj, false);
  77                         if (def == NULL)
  78                                 return -1;
  79
  80                         tmp = (Elf_Addr)(defobj->relocbase + def->st_value +
  81                             rela->r_addend);
  82
  83                         if (*where != tmp)
  84                                 *where = tmp;
  85                         rdbg(("32/GLOB_DAT %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(RELATIVE):  /* word32 B + A */
  91                         tmp = (Elf_Addr)(obj->relocbase + rela->r_addend);
  92                         if (*where != tmp)
  93                                 *where = tmp;
  94                         rdbg(("RELATIVE in %s --> %p", obj->path,
  95                             (void *)*where));
  96                         break;
  97
  98                 case R_TYPE(COPY):
  99                         /*
 100                          * These are deferred until all other relocations have
 101                          * been done.  All we do here is make sure that the
 102                          * COPY relocation is not in a shared library.  They
 103                          * are allowed only in executable files.
 104                          */
 105                         if (obj->isdynamic) {
 106                                 _rtld_error(
 107                         "%s: Unexpected R_COPY relocation in shared library",
 108                                     obj->path);
 109                                 return -1;
 110                         }
 111                         rdbg(("COPY (avoid in main)"));
 112                         break;
 113
 114                 default:
 115                         rdbg(("sym = %lu, type = %lu, offset = %p, "
 116                             "addend = %p, contents = %p, symbol = %s",
 117                             symnum, (u_long)ELF_R_TYPE(rela->r_info),
 118                             (void *)rela->r_offset, (void *)rela->r_addend,
 119                             (void *)*where,
 120                             obj->strtab + obj->symtab[symnum].st_name));
 121                         _rtld_error("%s: Unsupported relocation type %ld "
 122                             "in non-PLT relocations",
 123                             obj->path, (u_long) ELF_R_TYPE(rela->r_info));
 124                         return -1;
 125                 }
 126         }
 127         return 0;
 128 }
 129
 130 int
 131 _rtld_relocate_plt_lazy(const Obj_Entry *obj)
 132 {
 133         const Elf_Rela *rela;
 134
 135         if (!obj->relocbase)
 136                 return 0;
 137
 138         for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) {
 139                 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
 140
 141                 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
 142
 143                 /* Just relocate the GOT slots pointing into the PLT */
 144                 *where += (Elf_Addr)obj->relocbase;
 145                 rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where));
 146         }
 147
 148         return 0;
 149 }
 150
 151 static inline int
 152 _rtld_relocate_plt_object(const Obj_Entry *obj, const Elf_Rela *rela, Elf_Addr *tp)
 153 {
 154         Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
 155         Elf_Addr new_value;
 156         const Elf_Sym  *def;
 157         const Obj_Entry *defobj;
 158         unsigned long info = rela->r_info;
 159
 160         assert(ELF_R_TYPE(info) == R_TYPE(JMP_SLOT));
 161
 162         def = _rtld_find_plt_symdef(ELF_R_SYM(info), obj, &defobj, tp != NULL);
 163         if (__predict_false(def == NULL))
 164                 return -1;
 165         if (__predict_false(def == &_rtld_sym_zero))
 166                 return 0;
 167
 168         new_value = (Elf_Addr)(defobj->relocbase + def->st_value +
 169             rela->r_addend);
 170         rdbg(("bind now/fixup in %s --> old=%p new=%p",
 171             defobj->strtab + def->st_name, (void *)*where, (void *)new_value));
 172         if (*where != new_value)
 173                 *where = new_value;
 174
 175         if (tp)
 176                 *tp = new_value - rela->r_addend;
 177
 178         return 0;
 179 }
 180
 181 caddr_t
 182 _rtld_bind(const Obj_Entry *obj, Elf_Word reloff)
 183 {
 184         const Elf_Rela *rela = (const Elf_Rela *)((const uint8_t *)obj->pltrela + reloff);
 185         Elf_Addr result;
 186         int err;
 187
 188         result = 0;     /* XXX gcc */
 189
 190         err = _rtld_relocate_plt_object(obj, rela, &result);
 191         if (err)
 192                 _rtld_die();
 193
 194         return (caddr_t)result;
 195 }
 196
 197 int
 198 _rtld_relocate_plt_objects(const Obj_Entry *obj)
 199 {
 200         const Elf_Rela *rela;
 201
 202         for (rela = obj->pltrela; rela < obj->pltrelalim; rela++)
 203                 if (_rtld_relocate_plt_object(obj, rela, NULL) < 0)
 204                         return -1;
 205
 206         return 0;
 207 }