1 /* $NetBSD: mdreloc.c,v 1.16 2002/10/03 20:39:22 mycroft Exp $ */ 2 3 #include <sys/types.h> 4 #include <sys/stat.h> 5 6 #include "debug.h" 7 #include "rtld.h" 8 9 void _rtld_bind_start(void); 10 void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr); 11 caddr_t _rtld_bind __P((const Obj_Entry *, Elf_Word)); 12 13 void 14 _rtld_setup_pltgot(const Obj_Entry *obj) 15 { 16 obj->pltgot[1] = (Elf_Addr) obj; 17 obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start; 18 } 19 20 void 21 _rtld_relocate_nonplt_self(dynp, relocbase) 22 Elf_Dyn *dynp; 23 Elf_Addr relocbase; 24 { 25 const Elf_Rela *rela = 0, *relalim; 26 Elf_Addr relasz = 0; 27 Elf_Addr *where; 28 29 for (; dynp->d_tag != DT_NULL; dynp++) { 30 switch (dynp->d_tag) { 31 case DT_RELA: 32 rela = (const Elf_Rela *)(relocbase + dynp->d_un.d_ptr); 33 break; 34 case DT_RELASZ: 35 relasz = dynp->d_un.d_val; 36 break; 37 } 38 } 39 relalim = (const Elf_Rela *)((caddr_t)rela + relasz); 40 for (; rela < relalim; rela++) { 41 where = (Elf_Addr *)(relocbase + rela->r_offset); 42 *where += (Elf_Addr)relocbase; 43 } 44 } 45 46 int 47 _rtld_relocate_nonplt_objects(obj) 48 const Obj_Entry *obj; 49 { 50 const Elf_Rela *rela; 51 52 for (rela = obj->rela; rela < obj->relalim; rela++) { 53 Elf_Addr *where; 54 const Elf_Sym *def; 55 const Obj_Entry *defobj; 56 Elf_Addr tmp; 57 unsigned long symnum; 58 59 where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 60 symnum = ELF_R_SYM(rela->r_info); 61 62 switch (ELF_R_TYPE(rela->r_info)) { 63 case R_TYPE(NONE): 64 break; 65 66 #if 1 /* XXX should not occur */ 67 case R_TYPE(PC32): 68 def = _rtld_find_symdef(symnum, obj, &defobj, false); 69 if (def == NULL) 70 return -1; 71 72 tmp = (Elf_Addr)(defobj->relocbase + def->st_value + 73 rela->r_addend) - (Elf_Addr)where; 74 if (*where != tmp) 75 *where = tmp; 76 rdbg(("PC32 %s in %s --> %p in %s", 77 obj->strtab + obj->symtab[symnum].st_name, 78 obj->path, (void *)*where, defobj->path)); 79 break; 80 81 case R_TYPE(GOT32): 82 #endif 83 case R_TYPE(32): 84 case R_TYPE(GLOB_DAT): 85 def = _rtld_find_symdef(symnum, obj, &defobj, false); 86 if (def == NULL) 87 return -1; 88 89 tmp = (Elf_Addr)(defobj->relocbase + def->st_value + 90 rela->r_addend); 91 if (*where != tmp) 92 *where = tmp; 93 rdbg(("32/GLOB_DAT %s in %s --> %p in %s", 94 obj->strtab + obj->symtab[symnum].st_name, 95 obj->path, (void *)*where, defobj->path)); 96 break; 97 98 case R_TYPE(RELATIVE): 99 *where += (Elf_Addr)obj->relocbase; 100 rdbg(("RELATIVE in %s --> %p", obj->path, 101 (void *)*where)); 102 break; 103 104 case R_TYPE(COPY): 105 /* 106 * These are deferred until all other relocations have 107 * been done. All we do here is make sure that the 108 * COPY relocation is not in a shared library. They 109 * are allowed only in executable files. 110 */ 111 if (obj->isdynamic) { 112 _rtld_error( 113 "%s: Unexpected R_COPY relocation in shared library", 114 obj->path); 115 return -1; 116 } 117 rdbg(("COPY (avoid in main)")); 118 break; 119 120 default: 121 rdbg(("sym = %lu, type = %lu, offset = %p, " 122 "addend = %p, contents = %p, symbol = %s", 123 symnum, (u_long)ELF_R_TYPE(rela->r_info), 124 (void *)rela->r_offset, (void *)rela->r_addend, 125 (void *)*where, 126 obj->strtab + obj->symtab[symnum].st_name)); 127 _rtld_error("%s: Unsupported relocation type %ld " 128 "in non-PLT relocations\n", 129 obj->path, (u_long) ELF_R_TYPE(rela->r_info)); 130 return -1; 131 } 132 } 133 return 0; 134 } 135 136 int 137 _rtld_relocate_plt_lazy(obj) 138 const Obj_Entry *obj; 139 { 140 const Elf_Rela *rela; 141 142 if (!obj->relocbase) 143 return 0; 144 145 for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) { 146 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 147 148 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT)); 149 150 /* Just relocate the GOT slots pointing into the PLT */ 151 *where += (Elf_Addr)obj->relocbase; 152 rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where)); 153 } 154 155 return 0; 156 } 157 158 caddr_t 159 _rtld_bind(obj, reloff) 160 const Obj_Entry *obj; 161 Elf_Word reloff; 162 { 163 const Elf_Rela *rela = (const Elf_Rela *)((caddr_t)obj->pltrela + reloff); 164 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 165 Elf_Addr new_value; 166 const Elf_Sym *def; 167 const Obj_Entry *defobj; 168 169 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT)); 170 171 def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true); 172 if (def == NULL) 173 _rtld_die(); 174 175 new_value = (Elf_Addr)(defobj->relocbase + def->st_value); 176 rdbg(("bind now/fixup in %s --> old=%p new=%p", 177 defobj->strtab + def->st_name, (void *)*where, (void *)new_value)); 178 if (*where != new_value) 179 *where = new_value; 180 181 return (caddr_t)new_value; 182 } 183