mips_reloc.c revision 1.23
1 /* $NetBSD: mips_reloc.c,v 1.23 2002/09/12 22:56:30 mycroft Exp $ */ 2 3 /* 4 * Copyright 1997 Michael L. Hitch <mhitch (at) montana.edu> 5 * Portions copyright 2002 Charles M. Hannum. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. The name of the author may not be used to endorse or promote products 17 * derived from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 32 #include <stdarg.h> 33 #include <sys/types.h> 34 #include <sys/stat.h> 35 36 #include "debug.h" 37 #include "rtld.h" 38 39 void _rtld_bind_start(void); 40 void _rtld_relocate_nonplt_self(Elf_Dyn *, Elf_Addr); 41 caddr_t _rtld_bind_mips(Elf_Word, Elf_Addr, Elf_Addr, Elf_Addr); 42 43 caddr_t 44 _rtld_bind_mips(a0, a1, a2, a3) 45 Elf_Word a0; 46 Elf_Addr a1, a2, a3; 47 { 48 Elf_Addr *u = (Elf_Addr *)(a2 - 0x7ff0); 49 const Obj_Entry *obj = (Obj_Entry *)(u[1] & 0x7fffffff); 50 const Elf_Sym *def; 51 const Obj_Entry *defobj; 52 53 def = _rtld_find_symdef(a0, obj, &defobj, true); 54 if (def) { 55 u[obj->local_gotno + a0 - obj->gotsym] = (Elf_Addr) 56 (def->st_value + defobj->relocbase); 57 return((caddr_t)(def->st_value + defobj->relocbase)); 58 } 59 60 return(NULL); /* XXX */ 61 } 62 63 void 64 _rtld_setup_pltgot(obj) 65 const Obj_Entry *obj; 66 { 67 obj->pltgot[0] = (Elf_Addr) &_rtld_bind_start; 68 /* XXX only if obj->pltgot[1] & 0x80000000 ?? */ 69 obj->pltgot[1] |= (Elf_Addr) obj; 70 } 71 72 void 73 _rtld_relocate_nonplt_self(dynp, relocbase) 74 Elf_Dyn *dynp; 75 Elf_Addr relocbase; 76 { 77 const Elf_Rel *rel = 0, *rellim; 78 Elf_Addr relsz = 0; 79 Elf_Addr *where; 80 const Elf_Sym *symtab, *sym; 81 Elf_Addr *got; 82 Elf_Word local_gotno, symtabno, gotsym; 83 int i; 84 85 for (; dynp->d_tag != DT_NULL; dynp++) { 86 switch (dynp->d_tag) { 87 case DT_REL: 88 rel = (const Elf_Rel *)(relocbase + dynp->d_un.d_ptr); 89 break; 90 case DT_RELSZ: 91 relsz = dynp->d_un.d_val; 92 break; 93 case DT_SYMTAB: 94 symtab = (const Elf_Sym *)(relocbase + dynp->d_un.d_ptr); 95 break; 96 case DT_PLTGOT: 97 got = (Elf_Addr *)(relocbase + dynp->d_un.d_ptr); 98 break; 99 case DT_MIPS_LOCAL_GOTNO: 100 local_gotno = dynp->d_un.d_val; 101 break; 102 case DT_MIPS_SYMTABNO: 103 symtabno = dynp->d_un.d_val; 104 break; 105 case DT_MIPS_GOTSYM: 106 gotsym = dynp->d_un.d_val; 107 break; 108 } 109 } 110 rellim = (const Elf_Rel *)((caddr_t)rel + relsz); 111 for (; rel < rellim; rel++) { 112 where = (Elf_Addr *)(relocbase + rel->r_offset); 113 114 switch (ELF_R_TYPE(rel->r_info)) { 115 case R_TYPE(NONE): 116 break; 117 118 case R_TYPE(REL32): 119 sym = symtab + ELF_R_SYM(rel->r_info); 120 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL && 121 ELF_ST_TYPE(sym->st_info) == STT_SECTION) 122 *where += (Elf_Addr)(sym->st_value + relocbase); 123 else 124 abort(); 125 break; 126 127 default: 128 abort(); 129 } 130 } 131 132 i = (got[1] & 0x80000000) ? 2 : 1; 133 /* Relocate the local GOT entries */ 134 got += i; 135 for (; i < local_gotno; i++) 136 *got++ += relocbase; 137 sym = symtab + gotsym; 138 /* Now do the global GOT entries */ 139 for (i = gotsym; i < symtabno; i++) { 140 if (sym->st_shndx == SHN_UNDEF || 141 sym->st_shndx == SHN_COMMON) 142 *got = sym->st_value + relocbase; 143 else if (ELF_ST_TYPE(sym->st_info) == STT_FUNC && 144 *got != sym->st_value) 145 *got += relocbase; 146 else if (ELF_ST_TYPE(sym->st_info) == STT_SECTION && 147 ELF_ST_BIND(sym->st_info) == STB_GLOBAL) { 148 if (sym->st_shndx == SHN_ABS) 149 *got = sym->st_value + relocbase; 150 /* else SGI stuff ignored */ 151 } else 152 *got = sym->st_value + relocbase; 153 ++sym; 154 ++got; 155 } 156 } 157 158 int 159 _rtld_relocate_nonplt_objects(obj, self) 160 const Obj_Entry *obj; 161 bool self; 162 { 163 const Elf_Rel *rel; 164 Elf_Addr *got = obj->pltgot; 165 const Elf_Sym *sym, *def; 166 const Obj_Entry *defobj; 167 int i; 168 169 if (self) 170 return 0; 171 172 for (rel = obj->rel; rel < obj->rellim; rel++) { 173 Elf_Addr *where; 174 unsigned long symnum; 175 176 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 177 symnum = ELF_R_SYM(rel->r_info); 178 179 switch (ELF_R_TYPE(rel->r_info)) { 180 case R_TYPE(NONE): 181 break; 182 183 case R_TYPE(REL32): 184 /* 32-bit PC-relative reference */ 185 def = obj->symtab + symnum; 186 187 if (ELF_ST_BIND(def->st_info) == STB_LOCAL && 188 (ELF_ST_TYPE(def->st_info) == STT_SECTION || 189 ELF_ST_TYPE(def->st_info) == STT_NOTYPE)) { 190 /* 191 * XXX: ABI DIFFERENCE! 192 * 193 * Old NetBSD binutils would generate shared 194 * libs with section-relative relocations being 195 * already adjusted for the start address of 196 * the section. 197 * 198 * New binutils, OTOH, generate shared libs 199 * with the same relocations being based at 200 * zero, so we need to add in the start address 201 * of the section. 202 * 203 * We assume that all section-relative relocs 204 * with contents less than the start of the 205 * section need to be adjusted; this should 206 * work with both old and new shlibs. 207 * 208 * --rkb, Oct 6, 2001 209 */ 210 if (def->st_info == STT_SECTION && 211 *where < def->st_value) 212 *where += (Elf_Addr)def->st_value; 213 214 *where += (Elf_Addr)obj->relocbase; 215 216 rdbg(("REL32 %s in %s --> %p in %s", 217 obj->strtab + def->st_name, obj->path, 218 (void *)*where, obj->path)); 219 } else { 220 /* XXX maybe do something re: bootstrapping? */ 221 def = _rtld_find_symdef(symnum, obj, &defobj, 222 false); 223 if (def == NULL) 224 return -1; 225 *where += (Elf_Addr)(defobj->relocbase + 226 def->st_value); 227 rdbg(("REL32 %s in %s --> %p in %s", 228 obj->strtab + obj->symtab[symnum].st_name, 229 obj->path, (void *)*where, defobj->path)); 230 } 231 break; 232 233 default: 234 rdbg(("sym = %lu, type = %lu, offset = %p, " 235 "contents = %p, symbol = %s", 236 symnum, (u_long)ELF_R_TYPE(rel->r_info), 237 (void *)rel->r_offset, (void *)*where, 238 obj->strtab + obj->symtab[symnum].st_name)); 239 _rtld_error("%s: Unsupported relocation type %ld " 240 "in non-PLT relocations\n", 241 obj->path, (u_long) ELF_R_TYPE(rel->r_info)); 242 return -1; 243 } 244 } 245 246 i = (got[1] & 0x80000000) ? 2 : 1; 247 /* Relocate the local GOT entries */ 248 got += i; 249 for (; i < obj->local_gotno; i++) 250 *got++ += (Elf_Addr)obj->relocbase; 251 sym = obj->symtab + obj->gotsym; 252 /* Now do the global GOT entries */ 253 for (i = obj->gotsym; i < obj->symtabno; i++) { 254 rdbg((" doing got %d sym %p (%s, %x)", i - obj->gotsym, sym, 255 sym->st_name + obj->strtab, *got)); 256 257 def = _rtld_find_symdef(i, obj, &defobj, true); 258 if (def == NULL) 259 return -1; 260 if (sym->st_shndx == SHN_UNDEF || 261 sym->st_shndx == SHN_COMMON) 262 *got = def->st_value + (Elf_Addr)defobj->relocbase; 263 else if (ELF_ST_TYPE(sym->st_info) == STT_FUNC && 264 *got != sym->st_value) 265 *got += (Elf_Addr)obj->relocbase; 266 else if (ELF_ST_TYPE(sym->st_info) == STT_SECTION && 267 ELF_ST_BIND(sym->st_info) == STB_GLOBAL) { 268 if (sym->st_shndx == SHN_ABS) 269 *got = sym->st_value + 270 (Elf_Addr)obj->relocbase; 271 /* else SGI stuff ignored */ 272 } else 273 *got = def->st_value + (Elf_Addr)defobj->relocbase; 274 ++sym; 275 ++got; 276 } 277 278 return 0; 279 } 280 281 int 282 _rtld_relocate_plt_lazy(obj) 283 const Obj_Entry *obj; 284 { 285 const Elf_Rel *rel; 286 287 if (!obj->isdynamic) 288 return 0; 289 290 for (rel = obj->pltrel; rel < obj->pltrellim; rel++) { 291 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 292 293 /* Just relocate the GOT slots pointing into the PLT */ 294 *where += (Elf_Addr)obj->relocbase; 295 rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where)); 296 } 297 298 return 0; 299 } 300 301 int 302 _rtld_relocate_plt_object(obj, rela, addrp) 303 const Obj_Entry *obj; 304 const Elf_Rela *rela; 305 caddr_t *addrp; 306 { 307 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 308 Elf_Addr new_value; 309 310 /* Fully resolve procedure addresses now */ 311 312 if (obj->isdynamic) { 313 /* Just relocate the GOT slots pointing into the PLT */ 314 new_value = *where + (Elf_Addr)(obj->relocbase); 315 rdbg(("fixup !main in %s --> %p", obj->path, (void *)*where)); 316 } else { 317 return 0; 318 } 319 if (*where != new_value) 320 *where = new_value; 321 322 *addrp = (caddr_t)new_value; 323 return 0; 324 } 325
Indexes created Tue Sep 30 20:09:53 GMT 2025