1 /* $NetBSD: mdreloc.c,v 1.16 2002/10/03 20:39:23 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 + rela->r_addend); 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 case R_TYPE(32): /* word32 S + A */ 67 case R_TYPE(GLOB_DAT): /* word32 S + A */ 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); 74 75 if (*where != tmp) 76 *where = tmp; 77 rdbg(("32/GLOB_DAT %s in %s --> %p in %s", 78 obj->strtab + obj->symtab[symnum].st_name, 79 obj->path, (void *)*where, defobj->path)); 80 break; 81 82 case R_TYPE(RELATIVE): /* word32 B + A */ 83 tmp = (Elf_Addr)(obj->relocbase + rela->r_addend); 84 if (*where != tmp) 85 *where = tmp; 86 rdbg(("RELATIVE in %s --> %p", obj->path, 87 (void *)*where)); 88 break; 89 90 case R_TYPE(COPY): 91 /* 92 * These are deferred until all other relocations have 93 * been done. All we do here is make sure that the 94 * COPY relocation is not in a shared library. They 95 * are allowed only in executable files. 96 */ 97 if (obj->isdynamic) { 98 _rtld_error( 99 "%s: Unexpected R_COPY relocation in shared library", 100 obj->path); 101 return -1; 102 } 103 rdbg(("COPY (avoid in main)")); 104 break; 105 106 default: 107 rdbg(("sym = %lu, type = %lu, offset = %p, " 108 "addend = %p, contents = %p, symbol = %s", 109 symnum, (u_long)ELF_R_TYPE(rela->r_info), 110 (void *)rela->r_offset, (void *)rela->r_addend, 111 (void *)*where, 112 obj->strtab + obj->symtab[symnum].st_name)); 113 _rtld_error("%s: Unsupported relocation type %ld " 114 "in non-PLT relocations\n", 115 obj->path, (u_long) ELF_R_TYPE(rela->r_info)); 116 return -1; 117 } 118 } 119 return 0; 120 } 121 122 int 123 _rtld_relocate_plt_lazy(obj) 124 const Obj_Entry *obj; 125 { 126 const Elf_Rela *rela; 127 128 if (!obj->relocbase) 129 return 0; 130 131 for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) { 132 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 133 134 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT)); 135 136 /* Just relocate the GOT slots pointing into the PLT */ 137 *where += (Elf_Addr)obj->relocbase; 138 rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where)); 139 } 140 141 return 0; 142 } 143 144 caddr_t 145 _rtld_bind(obj, reloff) 146 const Obj_Entry *obj; 147 Elf_Word reloff; 148 { 149 const Elf_Rela *rela = (const Elf_Rela *)((caddr_t)obj->pltrela + reloff); 150 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 151 Elf_Addr new_value; 152 const Elf_Sym *def; 153 const Obj_Entry *defobj; 154 155 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT)); 156 157 def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true); 158 if (def == NULL) 159 _rtld_die(); 160 161 new_value = (Elf_Addr)(defobj->relocbase + def->st_value + 162 rela->r_addend); 163 rdbg(("bind now/fixup in %s --> old=%p new=%p", 164 defobj->strtab + def->st_name, (void *)*where, (void *)new_value)); 165 if (*where != new_value) 166 *where = new_value; 167 168 return (caddr_t)(new_value - rela->r_addend); 169 } 170