mdreloc.c revision 1.13
1 /* $NetBSD: mdreloc.c,v 1.13 2002/09/12 20:20:59 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, dodebug) 47 const Obj_Entry *obj; 48 bool self; 49 bool dodebug; 50 { 51 const Elf_Rel *rel; 52 53 if (self) 54 return 0; 55 56 for (rel = obj->rel; rel < obj->rellim; rel++) { 57 Elf_Addr *where; 58 const Elf_Sym *def; 59 const Obj_Entry *defobj; 60 Elf_Addr tmp; 61 unsigned long symnum; 62 63 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 64 symnum = ELF_R_SYM(rel->r_info); 65 66 switch (ELF_R_TYPE(rel->r_info)) { 67 case R_TYPE(NONE): 68 break; 69 70 #if 1 /* XXX should not occur */ 71 case R_TYPE(PC24): { /* word32 S - P + A */ 72 Elf32_Sword addend; 73 74 /* 75 * Extract addend and sign-extend if needed. 76 */ 77 addend = *where; 78 if (addend & 0x00800000) 79 addend |= 0xff000000; 80 81 def = _rtld_find_symdef(symnum, obj, &defobj, false); 82 if (def == NULL) 83 return -1; 84 tmp = (Elf_Addr)obj->relocbase + def->st_value 85 - (Elf_Addr)where + (addend << 2); 86 if ((tmp & 0xfe000000) != 0xfe000000 && 87 (tmp & 0xfe000000) != 0) { 88 _rtld_error( 89 "%s: R_ARM_PC24 relocation @ %p to %s failed " 90 "(displacement %ld (%#lx) out of range)", 91 obj->path, where, 92 obj->strtab + obj->symtab[symnum].st_name, 93 (long) tmp, (long) tmp); 94 return -1; 95 } 96 tmp >>= 2; 97 *where = (*where & 0xff000000) | (tmp & 0x00ffffff); 98 rdbg(dodebug, ("PC24 %s in %s --> %p @ %p in %s", 99 obj->strtab + obj->symtab[symnum].st_name, 100 obj->path, (void *)*where, where, defobj->path)); 101 break; 102 } 103 #endif 104 105 case R_TYPE(ABS32): /* word32 B + S + A */ 106 def = _rtld_find_symdef(symnum, obj, &defobj, false); 107 if (def == NULL) 108 return -1; 109 *where += (Elf_Addr)defobj->relocbase + def->st_value; 110 rdbg(dodebug, ("ABS32 %s in %s --> %p @ %p in %s", 111 obj->strtab + obj->symtab[symnum].st_name, 112 obj->path, (void *)*where, where, defobj->path)); 113 break; 114 115 case R_TYPE(GLOB_DAT): /* word32 B + S */ 116 def = _rtld_find_symdef(symnum, obj, &defobj, false); 117 if (def == NULL) 118 return -1; 119 *where = (Elf_Addr)(defobj->relocbase + def->st_value); 120 rdbg(dodebug, ("GLOB_DAT %s in %s --> %p @ %p in %s", 121 obj->strtab + obj->symtab[symnum].st_name, 122 obj->path, (void *)*where, where, defobj->path)); 123 break; 124 125 case R_TYPE(RELATIVE): /* word32 B + A */ 126 *where += (Elf_Addr)obj->relocbase; 127 rdbg(dodebug, ("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(dodebug, ("COPY (avoid in main)")); 145 break; 146 147 default: 148 rdbg(dodebug, ("sym = %lu, type = %lu, offset = %p, " 149 "contents = %p, symbol = %s", 150 symnum, (u_long)ELF_R_TYPE(rel->r_info), 151 (void *)rel->r_offset, (void *)*where, 152 obj->strtab + obj->symtab[symnum].st_name)); 153 _rtld_error("%s: Unsupported relocation type %ld " 154 "in non-PLT relocations\n", 155 obj->path, (u_long) ELF_R_TYPE(rel->r_info)); 156 return -1; 157 } 158 } 159 return 0; 160 } 161 162 int 163 _rtld_relocate_plt_lazy(obj, dodebug) 164 const Obj_Entry *obj; 165 bool dodebug; 166 { 167 const Elf_Rel *rel; 168 169 if (!obj->isdynamic) 170 return 0; 171 172 for (rel = obj->pltrel; rel < obj->pltrellim; rel++) { 173 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 174 175 assert(ELF_R_TYPE(rel->r_info) == R_TYPE(JUMP_SLOT)); 176 177 /* Just relocate the GOT slots pointing into the PLT */ 178 *where += (Elf_Addr)obj->relocbase; 179 rdbg(dodebug, ("fixup !main in %s --> %p", obj->path, 180 (void *)*where)); 181 } 182 183 return 0; 184 } 185 186 int 187 _rtld_relocate_plt_object(obj, rela, addrp, dodebug) 188 const Obj_Entry *obj; 189 const Elf_Rela *rela; 190 caddr_t *addrp; 191 bool dodebug; 192 { 193 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 194 Elf_Addr new_value; 195 const Elf_Sym *def; 196 const Obj_Entry *defobj; 197 198 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JUMP_SLOT)); 199 200 def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true); 201 if (def == NULL) 202 return -1; 203 204 new_value = (Elf_Addr)(defobj->relocbase + def->st_value); 205 rdbg(dodebug, ("bind now/fixup in %s --> old=%p new=%p", 206 defobj->strtab + def->st_name, (void *)*where, (void *)new_value)); 207 if (*where != new_value) 208 *where = new_value; 209 210 *addrp = (caddr_t)new_value; 211 return 0; 212 } 213
Indexes created Sat Oct 18 23:09:54 GMT 2025