mdreloc.c revision 1.18
1 /* $NetBSD: mdreloc.c,v 1.18 2003/07/05 20:48:39 marcus 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(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(Elf_Dyn *dynp, Elf_Addr relocbase) 22 { 23 const Elf_Rela *rela = 0, *relalim; 24 Elf_Addr relasz = 0; 25 Elf_Addr *where; 26 27 for (; dynp->d_tag != DT_NULL; dynp++) { 28 switch (dynp->d_tag) { 29 case DT_RELA: 30 rela = (const Elf_Rela *)(relocbase + dynp->d_un.d_ptr); 31 break; 32 case DT_RELASZ: 33 relasz = dynp->d_un.d_val; 34 break; 35 } 36 } 37 relalim = (const Elf_Rela *)((caddr_t)rela + relasz); 38 for (; rela < relalim; rela++) { 39 where = (Elf_Addr *)(relocbase + rela->r_offset); 40 *where = (Elf_Addr)(relocbase + rela->r_addend); 41 } 42 } 43 44 int 45 _rtld_relocate_nonplt_objects(obj) 46 const Obj_Entry *obj; 47 { 48 const Elf_Rela *rela; 49 50 for (rela = obj->rela; rela < obj->relalim; rela++) { 51 Elf_Addr *where; 52 const Elf_Sym *def; 53 const Obj_Entry *defobj; 54 Elf_Addr tmp; 55 unsigned long symnum; 56 57 where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 58 symnum = ELF_R_SYM(rela->r_info); 59 60 switch (ELF_R_TYPE(rela->r_info)) { 61 case R_TYPE(NONE): 62 break; 63 64 #if 1 /* XXX should not occur */ 65 case R_TYPE(GOT32): 66 def = _rtld_find_symdef(symnum, obj, &defobj, false); 67 if (def == NULL) 68 return -1; 69 70 tmp = (Elf_Addr)(defobj->relocbase + def->st_value + 71 rela->r_addend); 72 if (*where != tmp) 73 *where = tmp; 74 rdbg(("GOT32 %s in %s --> %p in %s", 75 obj->strtab + obj->symtab[symnum].st_name, 76 obj->path, (void *)*where, defobj->path)); 77 break; 78 79 case R_TYPE(REL32): 80 def = _rtld_find_symdef(symnum, obj, &defobj, false); 81 if (def == NULL) 82 return -1; 83 84 tmp = (Elf_Addr)(defobj->relocbase + def->st_value + 85 rela->r_addend) - (Elf_Addr)where; 86 if (*where != tmp) 87 *where = tmp; 88 rdbg(("PC32 %s in %s --> %p in %s", 89 obj->strtab + obj->symtab[symnum].st_name, 90 obj->path, (void *)*where, defobj->path)); 91 break; 92 #endif 93 94 case R_TYPE(DIR32): 95 def = _rtld_find_symdef(symnum, obj, &defobj, false); 96 if (def == NULL) 97 return -1; 98 99 tmp = (Elf_Addr)(defobj->relocbase + def->st_value + 100 rela->r_addend); 101 if (*where != tmp) 102 *where = tmp; 103 rdbg(("32 %s in %s --> %p in %s", 104 obj->strtab + obj->symtab[symnum].st_name, 105 obj->path, (void *)*where, defobj->path)); 106 break; 107 108 case R_TYPE(GLOB_DAT): 109 def = _rtld_find_symdef(symnum, obj, &defobj, false); 110 if (def == NULL) 111 return -1; 112 113 tmp = (Elf_Addr)(defobj->relocbase + def->st_value) + 114 rela->r_addend; 115 if (*where != tmp) 116 *where = tmp; 117 rdbg(("GLOB_DAT %s in %s --> %p in %s", 118 obj->strtab + obj->symtab[symnum].st_name, 119 obj->path, (void *)*where, defobj->path)); 120 break; 121 122 case R_TYPE(RELATIVE): 123 if (rela->r_addend) 124 *where = (Elf_Addr)obj->relocbase + rela->r_addend; 125 else 126 *where += (Elf_Addr)obj->relocbase; 127 rdbg(("RELATIVE in %s --> %p", obj->path, 128 (void *)*where)); 129 break; 130 131 case R_TYPE(COPY): 132 /* 133 * These are deferred until all other relocations have 134 * been done. All we do here is make sure that the 135 * COPY relocation is not in a shared library. They 136 * are allowed only in executable files. 137 */ 138 if (obj->isdynamic) { 139 _rtld_error( 140 "%s: Unexpected R_COPY relocation in shared library", 141 obj->path); 142 return -1; 143 } 144 rdbg(("COPY (avoid in main)")); 145 break; 146 147 default: 148 rdbg(("sym = %lu, type = %lu, offset = %p, " 149 "addend = %p, contents = %p, symbol = %s", 150 symnum, (u_long)ELF_R_TYPE(rela->r_info), 151 (void *)rela->r_offset, (void *)rela->r_addend, 152 (void *)*where, 153 obj->strtab + obj->symtab[symnum].st_name)); 154 _rtld_error("%s: Unsupported relocation type %ld " 155 "in non-PLT relocations\n", 156 obj->path, (u_long) ELF_R_TYPE(rela->r_info)); 157 return -1; 158 } 159 } 160 return 0; 161 } 162 163 int 164 _rtld_relocate_plt_lazy(obj) 165 const Obj_Entry *obj; 166 { 167 const Elf_Rela *rela; 168 169 if (!obj->relocbase) 170 return 0; 171 172 for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) { 173 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 174 175 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT)); 176 177 /* Just relocate the GOT slots pointing into the PLT */ 178 *where += (Elf_Addr)obj->relocbase; 179 rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where)); 180 } 181 182 return 0; 183 } 184 185 caddr_t 186 _rtld_bind(obj, reloff) 187 const Obj_Entry *obj; 188 Elf_Word reloff; 189 { 190 const Elf_Rela *rela = (const Elf_Rela *)((caddr_t)obj->pltrela + reloff); 191 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 192 Elf_Addr new_value; 193 const Elf_Sym *def; 194 const Obj_Entry *defobj; 195 196 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT)); 197 198 def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true); 199 if (def == NULL) 200 _rtld_die(); 201 202 new_value = (Elf_Addr)(defobj->relocbase + def->st_value); 203 rdbg(("bind now/fixup in %s --> old=%p new=%p", 204 defobj->strtab + def->st_name, (void *)*where, (void *)new_value)); 205 if (*where != new_value) 206 *where = new_value; 207 208 return (caddr_t)new_value; 209 } 210 211
Indexes created Tue Oct 21 12:09:54 GMT 2025