alpha_reloc.c revision 1.11
1 /* $NetBSD: alpha_reloc.c,v 1.11 2002/09/06 03:12:05 mycroft Exp $ */ 2 3 /* 4 * Copyright (c) 2001 Wasabi Systems, Inc. 5 * All rights reserved. 6 * 7 * Written by Jason R. Thorpe for Wasabi Systems, Inc. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed for the NetBSD Project by 20 * Wasabi Systems, Inc. 21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse 22 * or promote products derived from this software without specific prior 23 * written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC 29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35 * POSSIBILITY OF SUCH DAMAGE. 36 */ 37 38 #include <sys/types.h> 39 #include <sys/stat.h> 40 41 #include "rtld.h" 42 #include "debug.h" 43 44 #ifdef RTLD_DEBUG_ALPHA 45 #define adbg(x) if (dodebug) xprintf x 46 #else 47 #define adbg(x) /* nothing */ 48 #endif 49 50 void 51 _rtld_setup_pltgot(const Obj_Entry *obj) 52 { 53 uint32_t word0; 54 55 /* 56 * The PLTGOT on the Alpha looks like this: 57 * 58 * PLT HEADER 59 * . 60 * . 32 bytes 61 * . 62 * PLT ENTRY #0 63 * . 64 * . 12 bytes 65 * . 66 * PLT ENTRY #1 67 * . 68 * . 12 bytes 69 * . 70 * etc. 71 * 72 * The old-format entries look like (displacements filled in 73 * by the linker): 74 * 75 * ldah $28, 0($31) # 0x279f0000 76 * lda $28, 0($28) # 0x239c0000 77 * br $31, plt0 # 0xc3e00000 78 * 79 * The new-format entries look like: 80 * 81 * br $28, plt0 # 0xc3800000 82 * # 0x00000000 83 * # 0x00000000 84 * 85 * What we do is fetch the first PLT entry and check to 86 * see the first word of it matches the first word of the 87 * old format. If so, we use a binding routine that can 88 * handle the old format, otherwise we use a binding routine 89 * that handles the new format. 90 * 91 * Note that this is done on a per-object basis, we can mix 92 * and match shared objects build with both the old and new 93 * linker. 94 */ 95 word0 = *(uint32_t *)(((char *) obj->pltgot) + 32); 96 if ((word0 & 0xffff0000) == 0x279f0000) { 97 /* Old PLT entry format. */ 98 adbg(("ALPHA: object %p has old PLT format\n", obj)); 99 obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start_old; 100 obj->pltgot[3] = (Elf_Addr) obj; 101 } else { 102 /* New PLT entry format. */ 103 adbg(("ALPHA: object %p has new PLT format\n", obj)); 104 obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start; 105 obj->pltgot[3] = (Elf_Addr) obj; 106 } 107 108 __asm __volatile("imb"); 109 } 110 111 int 112 _rtld_relocate_nonplt_objects(obj, dodebug) 113 const Obj_Entry *obj; 114 bool dodebug; 115 { 116 const Elf_Rela *rela; 117 118 for (rela = obj->rela; rela < obj->relalim; rela++) { 119 Elf_Addr *where; 120 const Elf_Sym *def; 121 const Obj_Entry *defobj; 122 Elf_Addr tmp; 123 unsigned long symnum; 124 125 where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 126 symnum = ELF_R_SYM(rela->r_info); 127 128 switch (ELF_R_TYPE(rela->r_info)) { 129 case R_TYPE(NONE): 130 break; 131 132 case R_TYPE(REFQUAD): 133 def = _rtld_find_symdef(symnum, obj, &defobj, false); 134 if (def == NULL) 135 return -1; 136 137 tmp = (Elf_Addr)(defobj->relocbase + def->st_value) + 138 *where + rela->r_addend; 139 if (*where != tmp) 140 *where = tmp; 141 rdbg(dodebug, ("REFQUAD %s in %s --> %p in %s", 142 obj->strtab + obj->symtab[symnum].st_name, 143 obj->path, (void *)*where, defobj->path)); 144 break; 145 146 case R_TYPE(GLOB_DAT): 147 def = _rtld_find_symdef(symnum, obj, &defobj, false); 148 if (def == NULL) 149 return -1; 150 151 tmp = (Elf_Addr)(defobj->relocbase + def->st_value) + 152 rela->r_addend; 153 if (*where != tmp) 154 *where = tmp; 155 rdbg(dodebug, ("GLOB_DAT %s in %s --> %p in %s", 156 obj->strtab + obj->symtab[symnum].st_name, 157 obj->path, (void *)*where, defobj->path)); 158 break; 159 160 case R_TYPE(RELATIVE): 161 { 162 extern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; 163 extern Elf_Addr _GOT_END_[]; 164 165 /* This is the ...iffy hueristic. */ 166 if (!dodebug || 167 (caddr_t)where < (caddr_t)_GLOBAL_OFFSET_TABLE_ || 168 (caddr_t)where >= (caddr_t)_GOT_END_) { 169 *where += (Elf_Addr)obj->relocbase; 170 rdbg(dodebug, ("RELATIVE in %s --> %p", 171 obj->path, (void *)*where)); 172 } else 173 rdbg(dodebug, ("RELATIVE in %s stays at %p", 174 obj->path, (void *)*where)); 175 break; 176 } 177 178 case R_TYPE(COPY): 179 /* 180 * These are deferred until all other relocations have 181 * been done. All we do here is make sure that the 182 * COPY relocation is not in a shared library. They 183 * are allowed only in executable files. 184 */ 185 if (!obj->mainprog) { 186 _rtld_error( 187 "%s: Unexpected R_COPY relocation in shared library", 188 obj->path); 189 return -1; 190 } 191 rdbg(dodebug, ("COPY (avoid in main)")); 192 break; 193 194 default: 195 rdbg(dodebug, ("sym = %lu, type = %lu, offset = %p, " 196 "addend = %p, contents = %p, symbol = %s", 197 symnum, (u_long)ELF_R_TYPE(rela->r_info), 198 (void *)rela->r_offset, (void *)rela->r_addend, 199 (void *)*where, 200 obj->strtab + obj->symtab[symnum].st_name)); 201 _rtld_error("%s: Unsupported relocation type %ld " 202 "in non-PLT relocations\n", 203 obj->path, (u_long) ELF_R_TYPE(rela->r_info)); 204 return -1; 205 } 206 } 207 return 0; 208 } 209 210 int 211 _rtld_relocate_plt_lazy(obj, dodebug) 212 const Obj_Entry *obj; 213 bool dodebug; 214 { 215 const Elf_Rela *rela; 216 217 if (obj->mainprog) 218 return 0; 219 220 for (rela = obj->pltrela; rela < obj->pltrelalim; rela++) { 221 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 222 223 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT)); 224 225 /* Just relocate the GOT slots pointing into the PLT */ 226 *where += (Elf_Addr)obj->relocbase; 227 rdbg(dodebug, ("fixup !main in %s --> %p", obj->path, 228 (void *)*where)); 229 } 230 231 return 0; 232 } 233 234 int 235 _rtld_relocate_plt_object(obj, rela, addrp, dodebug) 236 const Obj_Entry *obj; 237 const Elf_Rela *rela; 238 caddr_t *addrp; 239 bool dodebug; 240 { 241 Elf_Addr *where = (Elf_Addr *)(obj->relocbase + rela->r_offset); 242 Elf_Addr new_value; 243 const Elf_Sym *def; 244 const Obj_Entry *defobj; 245 246 assert(ELF_R_TYPE(rela->r_info) == R_TYPE(JMP_SLOT)); 247 248 def = _rtld_find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true); 249 if (def == NULL) 250 return -1; 251 252 new_value = (Elf_Addr)(defobj->relocbase + def->st_value); 253 rdbg(dodebug, ("bind now/fixup in %s --> old=%p new=%p", 254 defobj->strtab + def->st_name, (void *)*where, (void *)new_value)); 255 if (*where != new_value) 256 *where = new_value; 257 258 *addrp = (caddr_t)new_value; 259 return 0; 260 } 261
Indexes created Sun Oct 12 09:09:55 GMT 2025