mips_reloc.c revision 1.22
1 /* $NetBSD: mips_reloc.c,v 1.22 2002/09/12 20:21:00 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, dodebug) 160 const Obj_Entry *obj; 161 bool self; 162 bool dodebug; 163 { 164 const Elf_Rel *rel; 165 Elf_Addr *got = obj->pltgot; 166 const Elf_Sym *sym, *def; 167 const Obj_Entry *defobj; 168 int i; 169 170 if (self) 171 return 0; 172 173 for (rel = obj->rel; rel < obj->rellim; rel++) { 174 Elf_Addr *where; 175 unsigned long symnum; 176 177 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 178 symnum = ELF_R_SYM(rel->r_info); 179 180 switch (ELF_R_TYPE(rel->r_info)) { 181 case R_TYPE(NONE): 182 break; 183 184 case R_TYPE(REL32): 185 /* 32-bit PC-relative reference */ 186 def = obj->symtab + symnum; 187 188 if (ELF_ST_BIND(def->st_info) == STB_LOCAL && 189 (ELF_ST_TYPE(def->st_info) == STT_SECTION || 190 ELF_ST_TYPE(def->st_info) == STT_NOTYPE)) { 191 /* 192 * XXX: ABI DIFFERENCE! 193 * 194 * Old NetBSD binutils would generate shared 195 * libs with section-relative relocations being 196 * already adjusted for the start address of 197 * the section. 198 * 199 * New binutils, OTOH, generate shared libs 200 * with the same relocations being based at 201 * zero, so we need to add in the start address 202 * of the section. 203 * 204 * We assume that all section-relative relocs 205 * with contents less than the start of the 206 * section need to be adjusted; this should 207 * work with both old and new shlibs. 208 * 209 * --rkb, Oct 6, 2001 210 */ 211 if (def->st_info == STT_SECTION && 212 *where < def->st_value) 213 *where += (Elf_Addr)def->st_value; 214 215 *where += (Elf_Addr)obj->relocbase; 216 217 rdbg(dodebug, ("REL32 %s in %s --> %p in %s", 218 obj->strtab + def->st_name, obj->path, 219 (void *)*where, obj->path)); 220 } else { 221 /* XXX maybe do something re: bootstrapping? */ 222 def = _rtld_find_symdef(symnum, obj, &defobj, 223 false); 224 if (def == NULL) 225 return -1; 226 *where += (Elf_Addr)(defobj->relocbase + 227 def->st_value); 228 rdbg(dodebug, ("REL32 %s in %s --> %p in %s", 229 obj->strtab + obj->symtab[symnum].st_name, 230 obj->path, (void *)*where, defobj->path)); 231 } 232 break; 233 234 default: 235 rdbg(dodebug, ("sym = %lu, type = %lu, offset = %p, " 236 "contents = %p, symbol = %s", 237 symnum, (u_long)ELF_R_TYPE(rel->r_info), 238 (void *)rel->r_offset, (void *)*where, 239 obj->strtab + obj->symtab[symnum].st_name)); 240 _rtld_error("%s: Unsupported relocation type %ld " 241 "in non-PLT relocations\n", 242 obj->path, (u_long) ELF_R_TYPE(rel->r_info)); 243 return -1; 244 } 245 } 246 247 i = (got[1] & 0x80000000) ? 2 : 1; 248 /* Relocate the local GOT entries */ 249 got += i; 250 for (; i < obj->local_gotno; i++) 251 *got++ += (Elf_Addr)obj->relocbase; 252 sym = obj->symtab + obj->gotsym; 253 /* Now do the global GOT entries */ 254 for (i = obj->gotsym; i < obj->symtabno; i++) { 255 rdbg(1, (" doing got %d sym %p (%s, %x)", i - obj->gotsym, 256 sym, sym->st_name + obj->strtab, *got)); 257 258 def = _rtld_find_symdef(i, obj, &defobj, true); 259 if (def == NULL) 260 return -1; 261 if (sym->st_shndx == SHN_UNDEF || 262 sym->st_shndx == SHN_COMMON) 263 *got = def->st_value + (Elf_Addr)defobj->relocbase; 264 else if (ELF_ST_TYPE(sym->st_info) == STT_FUNC && 265 *got != sym->st_value) 266 *got += (Elf_Addr)obj->relocbase; 267 else if (ELF_ST_TYPE(sym->st_info) == STT_SECTION && 268 ELF_ST_BIND(sym->st_info) == STB_GLOBAL) { 269 if (sym->st_shndx == SHN_ABS) 270 *got = sym->st_value + 271 (Elf_Addr)obj->relocbase; 272 /* else SGI stuff ignored */ 273 } else 274 *got = def->st_value + (Elf_Addr)defobj->relocbase; 275 ++sym; 276 ++got; 277 } 278 279 return 0; 280 } 281 282 int 283 _rtld_relocate_plt_lazy(obj, dodebug) 284 const Obj_Entry *obj; 285 bool dodebug; 286 { 287 const Elf_Rel *rel; 288 289 if (!obj->isdynamic) 290 return 0; 291 292 for (rel = obj->pltrel; rel < obj->pltrellim; rel++) { 293 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 294 295 /* Just relocate the GOT slots pointing into the PLT */ 296 *where += (Elf_Addr)obj->relocbase; 297 rdbg(dodebug, ("fixup !main in %s --> %p", obj->path, 298 (void *)*where)); 299 } 300 301 return 0; 302 } 303 304 int 305 _rtld_relocate_plt_object(obj, rela, addrp, dodebug) 306 const Obj_Entry *obj; 307 const Elf_Rela *rela; 308 caddr_t *addrp; 309 bool dodebug; 310 { 311 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 312 Elf_Addr new_value; 313 314 /* Fully resolve procedure addresses now */ 315 316 if (obj->isdynamic) { 317 /* Just relocate the GOT slots pointing into the PLT */ 318 new_value = *where + (Elf_Addr)(obj->relocbase); 319 rdbg(dodebug, ("fixup !main in %s --> %p", obj->path, 320 (void *)*where)); 321 } else { 322 return 0; 323 } 324 if (*where != new_value) 325 *where = new_value; 326 327 *addrp = (caddr_t)new_value; 328 return 0; 329 } 330
Indexes created Tue Sep 30 17:09:57 GMT 2025