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

   1 /*      $NetBSD: mdreloc.c,v 1.24 2009/03/16 02:46:48 lukem Exp $       */
   2
   3 #include <sys/cdefs.h>
   4 #ifndef lint
   5 __RCSID("$NetBSD: mdreloc.c,v 1.24 2009/03/16 02:46:48 lukem Exp $");
   6 #endif /* not lint */
   7
   8 #include <sys/cdefs.h>
   9 #ifndef lint
  10 __RCSID("$NetBSD: mdreloc.c,v 1.24 2009/03/16 02:46:48 lukem Exp $");
  11 #endif /* not lint */
  12
  13 #include <sys/types.h>
  14 #include <sys/stat.h>
  15
  16 #include "debug.h"
  17 #include "rtld.h"
  18
  19 void _rtld_bind_start(void);
  20 void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr);
  21 caddr_t _rtld_bind(const Obj_Entry *, Elf_Word);
  22 static inline int _rtld_relocate_plt_object(const Obj_Entry *,
  23     const Elf_Rela *, Elf_Addr *);
  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 + rela->r_addend);
  53         }
  54 }
  55
  56 int
  57 _rtld_relocate_nonplt_objects(const 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                 case R_TYPE(32):        /* word32 S + A */
  76                 case R_TYPE(GLOB_DAT):  /* word32 S + A */
  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);
  83
  84                         if (*where != tmp)
  85                                 *where = tmp;
  86                         rdbg(("32/GLOB_DAT %s in %s --> %p in %s",
  87                             obj->strtab + obj->symtab[symnum].st_name,
  88                             obj->path, (void *)*where, defobj->path));
  89                         break;
  90
  91                 case R_TYPE(RELATIVE):  /* word32 B + A */
  92                         tmp = (Elf_Addr)(obj->relocbase + rela->r_addend);
  93                         if (*where != tmp)
  94                                 *where = tmp;
  95                         rdbg(("RELATIVE in %s --> %p", obj->path,
  96                             (void *)*where));
  97                         break;
  98
  99                 case R_TYPE(COPY):
 100                         /*
 101                          * These are deferred until all other relocations have
 102                          * been done.  All we do here is make sure that the
 103                          * COPY relocation is not in a shared library.  They
 104                          * are allowed only in executable files.
 105                          */
 106                         if (obj->isdynamic) {
 107                                 _rtld_error(
 108                         "%s: Unexpected R_COPY relocation in shared library",
 109                                     obj->path);
 110                                 return -1;
 111                         }
 112                         rdbg(("COPY (avoid in main)"));
 113                         break;
 114
 115                 default:
 116                         rdbg(("sym = %lu, type = %lu, offset = %p, "
 117                             "addend = %p, contents = %p, symbol = %s",
 118                             symnum, (u_long)ELF_R_TYPE(rela->r_info),
 119                             (void *)rela->r_offset, (void *)rela->r_addend,
 120                             (void *)*where,
 121                             obj->strtab + obj->symtab[symnum].st_name));
 122                         _rtld_error("%s: Unsupported relocation type %ld "
 123                             "in non-PLT relocations",
 124                             obj->path, (u_long) ELF_R_TYPE(rela->r_info));
 125                         return -1;
 126                 }
 127         }
 128         return 0;
 129 }
 130
 131 int
 132 _rtld_relocate_plt_lazy(const Obj_Entry *obj)
 133 {
 134         const Elf_Rela *rela;
 135
 136         if (!obj->relocbase)
 137                 return 0;
 138
 139         for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) {
 140                 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
 141
 142                 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
 143
 144                 /* Just relocate the GOT slots pointing into the PLT */
 145                 *where += (Elf_Addr)obj->relocbase;
 146                 rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where));
 147         }
 148
 149         return 0;
 150 }
 151
 152 static inline int
 153 _rtld_relocate_plt_object(const Obj_Entry *obj, const Elf_Rela *rela, Elf_Addr *tp)
 154 {
 155         Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset);
 156         Elf_Addr new_value;
 157         const Elf_Sym  *def;
 158         const Obj_Entry *defobj;
 159
 160         assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT));
 161
 162         def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true);
 163         if (def == NULL)
 164                 return -1;
 165
 166         new_value = (Elf_Addr)(defobj->relocbase + def->st_value +
 167             rela->r_addend);
 168         rdbg(("bind now/fixup in %s --> old=%p new=%p",
 169             defobj->strtab + def->st_name, (void *)*where, (void *)new_value));
 170         if (*where != new_value)
 171                 *where = new_value;
 172
 173         if (tp)
 174                 *tp = new_value - rela->r_addend;
 175
 176         return 0;
 177 }
 178
 179 caddr_t
 180 _rtld_bind(const Obj_Entry *obj, Elf_Word reloff)
 181 {
 182         const Elf_Rela *rela = (const Elf_Rela *)((const uint8_t *)obj->pltrela + reloff);
 183         Elf_Addr result;
 184         int err;
 185
 186         result = 0;     /* XXX gcc */
 187
 188         err = _rtld_relocate_plt_object(obj, rela, &result);
 189         if (err || result == 0)
 190                 _rtld_die();
 191
 192         return (caddr_t)result;
 193 }
 194
 195 int
 196 _rtld_relocate_plt_objects(const Obj_Entry *obj)
 197 {
 198         const Elf_Rela *rela;
 199
 200         for (rela = obj->pltrela; rela < obj->pltrelalim; rela++)
 201                 if (_rtld_relocate_plt_object(obj, rela, NULL) < 0)
 202                         return -1;
 203
 204         return 0;
 205 }