mdreloc.c revision 1.14
1 /* $NetBSD: mdreloc.c,v 1.14 2002/09/12 22:56:30 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 12 void 13 _rtld_setup_pltgot(const Obj_Entry *obj) 14 { 15 obj->pltgot[1] = (Elf_Addr) obj; 16 obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start; 17 } 18 19 void 20 _rtld_relocate_nonplt_self(dynp, relocbase) 21 Elf_Dyn *dynp; 22 Elf_Addr relocbase; 23 { 24 const Elf_Rel *rel = 0, *rellim; 25 Elf_Addr relsz = 0; 26 Elf_Addr *where; 27 28 for (; dynp->d_tag != DT_NULL; dynp++) { 29 switch (dynp->d_tag) { 30 case DT_REL: 31 rel = (const Elf_Rel *)(relocbase + dynp->d_un.d_ptr); 32 break; 33 case DT_RELSZ: 34 relsz = dynp->d_un.d_val; 35 break; 36 } 37 } 38 rellim = (const Elf_Rel *)((caddr_t)rel + relsz); 39 for (; rel < rellim; rel++) { 40 where = (Elf_Addr *)(relocbase + rel->r_offset); 41 *where += (Elf_Addr)relocbase; 42 } 43 } 44 45 int 46 _rtld_relocate_nonplt_objects(obj, self) 47 const Obj_Entry *obj; 48 bool self; 49 { 50 const Elf_Rel *rel; 51 #define COMBRELOC 52 #ifdef COMBRELOC 53 unsigned long lastsym = -1; 54 #endif 55 Elf_Addr target; 56 57 if (self) 58 return 0; 59 60 for (rel = obj->rel; rel < obj->rellim; rel++) { 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 + rel->r_offset); 68 symnum = ELF_R_SYM(rel->r_info); 69 70 switch (ELF_R_TYPE(rel->r_info)) { 71 case R_TYPE(NONE): 72 break; 73 74 #if 1 /* XXX should not occur */ 75 case R_TYPE(PC32): 76 #ifdef COMBRELOC 77 if (symnum != lastsym) { 78 #endif 79 def = _rtld_find_symdef(symnum, obj, &defobj, 80 false); 81 if (def == NULL) 82 return -1; 83 target = (Elf_Addr)(defobj->relocbase + 84 def->st_value); 85 #ifdef COMBRELOC 86 lastsym = symnum; 87 } 88 #endif 89 90 *where += target - (Elf_Addr)where; 91 rdbg(("PC32 %s in %s --> %p in %s", 92 obj->strtab + obj->symtab[symnum].st_name, 93 obj->path, (void *)*where, defobj->path)); 94 break; 95 96 case R_TYPE(GOT32): 97 #endif 98 case R_TYPE(32): 99 case R_TYPE(GLOB_DAT): 100 #ifdef COMBRELOC 101 if (symnum != lastsym) { 102 #endif 103 def = _rtld_find_symdef(symnum, obj, &defobj, 104 false); 105 if (def == NULL) 106 return -1; 107 target = (Elf_Addr)(defobj->relocbase + 108 def->st_value); 109 #ifdef COMBRELOC 110 lastsym = symnum; 111 } 112 #endif 113 114 tmp = target + *where; 115 if (*where != tmp) 116 *where = tmp; 117 rdbg(("32/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 *where += (Elf_Addr)obj->relocbase; 124 rdbg(("RELATIVE in %s --> %p", obj->path, 125 (void *)*where)); 126 break; 127 128 case R_TYPE(COPY): 129 /* 130 * These are deferred until all other relocations have 131 * been done. All we do here is make sure that the 132 * COPY relocation is not in a shared library. They 133 * are allowed only in executable files. 134 */ 135 if (obj->isdynamic) { 136 _rtld_error( 137 "%s: Unexpected R_COPY relocation in shared library", 138 obj->path); 139 return -1; 140 } 141 rdbg(("COPY (avoid in main)")); 142 break; 143 144 default: 145 rdbg(("sym = %lu, type = %lu, offset = %p, " 146 "contents = %p, symbol = %s", 147 symnum, (u_long)ELF_R_TYPE(rel->r_info), 148 (void *)rel->r_offset, (void *)*where, 149 obj->strtab + obj->symtab[symnum].st_name)); 150 _rtld_error("%s: Unsupported relocation type %ld " 151 "in non-PLT relocations\n", 152 obj->path, (u_long) ELF_R_TYPE(rel->r_info)); 153 return -1; 154 } 155 } 156 return 0; 157 } 158 159 int 160 _rtld_relocate_plt_lazy(obj) 161 const Obj_Entry *obj; 162 { 163 const Elf_Rel *rel; 164 165 if (!obj->isdynamic) 166 return 0; 167 168 for (rel = obj->pltrel; rel < obj->pltrellim; rel++) { 169 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 170 171 assert(ELF_R_TYPE(rel->r_info) == R_TYPE(JMP_SLOT)); 172 173 /* Just relocate the GOT slots pointing into the PLT */ 174 *where += (Elf_Addr)obj->relocbase; 175 rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where)); 176 } 177 178 return 0; 179 } 180 181 int 182 _rtld_relocate_plt_object(obj, rela, addrp) 183 const Obj_Entry *obj; 184 const Elf_Rela *rela; 185 caddr_t *addrp; 186 { 187 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 188 Elf_Addr new_value; 189 const Elf_Sym *def; 190 const Obj_Entry *defobj; 191 192 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT)); 193 194 def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true); 195 if (def == NULL) 196 return -1; 197 198 new_value = (Elf_Addr)(defobj->relocbase + def->st_value); 199 rdbg(("bind now/fixup in %s --> old=%p new=%p", 200 defobj->strtab + def->st_name, (void *)*where, (void *)new_value)); 201 if (*where != new_value) 202 *where = new_value; 203 204 *addrp = (caddr_t)new_value; 205 return 0; 206 } 207
Indexes created Mon Sep 29 21:09:56 GMT 2025