mdreloc.c revision 1.14
1 /* $NetBSD: mdreloc.c,v 1.14 2002/09/12 22:56:29 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 52 if (self) 53 return 0; 54 55 for (rel = obj->rel; rel < obj->rellim; rel++) { 56 Elf_Addr *where; 57 const Elf_Sym *def; 58 const Obj_Entry *defobj; 59 Elf_Addr tmp; 60 unsigned long symnum; 61 62 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 63 symnum = ELF_R_SYM(rel->r_info); 64 65 switch (ELF_R_TYPE(rel->r_info)) { 66 case R_TYPE(NONE): 67 break; 68 69 #if 1 /* XXX should not occur */ 70 case R_TYPE(PC24): { /* word32 S - P + A */ 71 Elf32_Sword addend; 72 73 /* 74 * Extract addend and sign-extend if needed. 75 */ 76 addend = *where; 77 if (addend & 0x00800000) 78 addend |= 0xff000000; 79 80 def = _rtld_find_symdef(symnum, obj, &defobj, false); 81 if (def == NULL) 82 return -1; 83 tmp = (Elf_Addr)obj->relocbase + def->st_value 84 - (Elf_Addr)where + (addend << 2); 85 if ((tmp & 0xfe000000) != 0xfe000000 && 86 (tmp & 0xfe000000) != 0) { 87 _rtld_error( 88 "%s: R_ARM_PC24 relocation @ %p to %s failed " 89 "(displacement %ld (%#lx) out of range)", 90 obj->path, where, 91 obj->strtab + obj->symtab[symnum].st_name, 92 (long) tmp, (long) tmp); 93 return -1; 94 } 95 tmp >>= 2; 96 *where = (*where & 0xff000000) | (tmp & 0x00ffffff); 97 rdbg(("PC24 %s in %s --> %p @ %p in %s", 98 obj->strtab + obj->symtab[symnum].st_name, 99 obj->path, (void *)*where, where, defobj->path)); 100 break; 101 } 102 #endif 103 104 case R_TYPE(ABS32): /* word32 B + S + A */ 105 def = _rtld_find_symdef(symnum, obj, &defobj, false); 106 if (def == NULL) 107 return -1; 108 *where += (Elf_Addr)defobj->relocbase + def->st_value; 109 rdbg(("ABS32 %s in %s --> %p @ %p in %s", 110 obj->strtab + obj->symtab[symnum].st_name, 111 obj->path, (void *)*where, where, defobj->path)); 112 break; 113 114 case R_TYPE(GLOB_DAT): /* word32 B + S */ 115 def = _rtld_find_symdef(symnum, obj, &defobj, false); 116 if (def == NULL) 117 return -1; 118 *where = (Elf_Addr)(defobj->relocbase + def->st_value); 119 rdbg(("GLOB_DAT %s in %s --> %p @ %p in %s", 120 obj->strtab + obj->symtab[symnum].st_name, 121 obj->path, (void *)*where, where, defobj->path)); 122 break; 123 124 case R_TYPE(RELATIVE): /* word32 B + A */ 125 *where += (Elf_Addr)obj->relocbase; 126 rdbg(("RELATIVE in %s --> %p", obj->path, 127 (void *)*where)); 128 break; 129 130 case R_TYPE(COPY): 131 /* 132 * These are deferred until all other relocations have 133 * been done. All we do here is make sure that the 134 * COPY relocation is not in a shared library. They 135 * are allowed only in executable files. 136 */ 137 if (obj->isdynamic) { 138 _rtld_error( 139 "%s: Unexpected R_COPY relocation in shared library", 140 obj->path); 141 return -1; 142 } 143 rdbg(("COPY (avoid in main)")); 144 break; 145 146 default: 147 rdbg(("sym = %lu, type = %lu, offset = %p, " 148 "contents = %p, symbol = %s", 149 symnum, (u_long)ELF_R_TYPE(rel->r_info), 150 (void *)rel->r_offset, (void *)*where, 151 obj->strtab + obj->symtab[symnum].st_name)); 152 _rtld_error("%s: Unsupported relocation type %ld " 153 "in non-PLT relocations\n", 154 obj->path, (u_long) ELF_R_TYPE(rel->r_info)); 155 return -1; 156 } 157 } 158 return 0; 159 } 160 161 int 162 _rtld_relocate_plt_lazy(obj) 163 const Obj_Entry *obj; 164 { 165 const Elf_Rel *rel; 166 167 if (!obj->isdynamic) 168 return 0; 169 170 for (rel = obj->pltrel; rel < obj->pltrellim; rel++) { 171 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 172 173 assert(ELF_R_TYPE(rel->r_info) == R_TYPE(JUMP_SLOT)); 174 175 /* Just relocate the GOT slots pointing into the PLT */ 176 *where += (Elf_Addr)obj->relocbase; 177 rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where)); 178 } 179 180 return 0; 181 } 182 183 int 184 _rtld_relocate_plt_object(obj, rela, addrp) 185 const Obj_Entry *obj; 186 const Elf_Rela *rela; 187 caddr_t *addrp; 188 { 189 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 190 Elf_Addr new_value; 191 const Elf_Sym *def; 192 const Obj_Entry *defobj; 193 194 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JUMP_SLOT)); 195 196 def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true); 197 if (def == NULL) 198 return -1; 199 200 new_value = (Elf_Addr)(defobj->relocbase + def->st_value); 201 rdbg(("bind now/fixup in %s --> old=%p new=%p", 202 defobj->strtab + def->st_name, (void *)*where, (void *)new_value)); 203 if (*where != new_value) 204 *where = new_value; 205 206 *addrp = (caddr_t)new_value; 207 return 0; 208 } 209
Indexes created Mon Sep 29 15:09:53 GMT 2025