1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright (c) 1988 AT&T 24 * All Rights Reserved 25 * 26 */ 27 28 /* 29 * Copyright (c) 1998 by Sun Microsystems, Inc. 30 * All rights reserved. 31 */ 32 33 #pragma ident "%Z%%M% %I% %E% SMI" /* SVr4.0 1.13 */ 34 35 #pragma weak elf_begin = _elf_begin 36 #pragma weak elf_memory = _elf_memory 37 38 39 #include "syn.h" 40 #include <ar.h> 41 #include <stdlib.h> 42 #include <memory.h> 43 #include <errno.h> 44 #include <libelf.h> 45 #include <sys/mman.h> 46 #include "decl.h" 47 #include "member.h" 48 #include "msg.h" 49 50 static const char armag[] = ARMAG; 51 52 53 /* 54 * Initialize archive member 55 */ 56 Elf * 57 _elf_member(int fd, Elf * ref, unsigned flags) 58 { 59 register Elf *elf; 60 Member *mh; 61 size_t base; 62 63 if (ref->ed_nextoff >= ref->ed_fsz) 64 return (0); 65 if (ref->ed_fd == -1) /* disabled */ 66 fd = -1; 67 if (flags & EDF_WRITE) { 68 _elf_seterr(EREQ_ARRDWR, 0); 69 return (0); 70 } 71 if (ref->ed_fd != fd) { 72 _elf_seterr(EREQ_ARMEMFD, 0); 73 return (0); 74 } 75 if ((_elf_vm(ref, ref->ed_nextoff, sizeof (struct ar_hdr)) != 76 OK_YES) || ((mh = _elf_armem(ref, 77 ref->ed_ident + ref->ed_nextoff, ref->ed_fsz)) == 0)) 78 return (0); 79 80 base = ref->ed_nextoff + sizeof (struct ar_hdr); 81 if (ref->ed_fsz - base < mh->m_hdr.ar_size) { 82 _elf_seterr(EFMT_ARMEMSZ, 0); 83 return (0); 84 } 85 if ((elf = (Elf *)calloc(1, sizeof (Elf))) == 0) { 86 _elf_seterr(EMEM_ELF, errno); 87 return (0); 88 } 89 ++ref->ed_activ; 90 elf->ed_parent = ref; 91 elf->ed_fd = fd; 92 elf->ed_myflags |= flags; 93 elf->ed_armem = mh; 94 elf->ed_fsz = mh->m_hdr.ar_size; 95 elf->ed_baseoff = ref->ed_baseoff + base; 96 elf->ed_memoff = base - mh->m_slide; 97 elf->ed_siboff = base + elf->ed_fsz + (elf->ed_fsz & 1); 98 ref->ed_nextoff = elf->ed_siboff; 99 elf->ed_image = ref->ed_image; 100 elf->ed_imagesz = ref->ed_imagesz; 101 elf->ed_vm = ref->ed_vm; 102 elf->ed_vmsz = ref->ed_vmsz; 103 elf->ed_ident = ref->ed_ident + base - mh->m_slide; 104 105 /* 106 * If this member is the archive string table, 107 * we've already altered the bytes. 108 */ 109 110 if (ref->ed_arstroff == ref->ed_nextoff) 111 elf->ed_status = ES_COOKED; 112 return (elf); 113 } 114 115 116 Elf * 117 _elf_regular(int fd, unsigned flags) /* initialize regular file */ 118 { 119 Elf *elf; 120 121 if ((elf = (Elf *)calloc(1, sizeof (Elf))) == 0) { 122 _elf_seterr(EMEM_ELF, errno); 123 return (0); 124 } 125 126 NOTE(NOW_INVISIBLE_TO_OTHER_THREADS(*elf)) 127 elf->ed_fd = fd; 128 elf->ed_myflags |= flags; 129 if (_elf_inmap(elf) != OK_YES) { 130 free(elf); 131 return (0); 132 } 133 NOTE(NOW_VISIBLE_TO_OTHER_THREADS(*elf)) 134 return (elf); 135 } 136 137 138 Elf * 139 _elf_config(Elf * elf) 140 { 141 char * base; 142 unsigned encode; 143 144 ELFRWLOCKINIT(&elf->ed_rwlock); 145 146 /* 147 * Determine if this is a ELF file. 148 */ 149 base = elf->ed_ident; 150 if ((elf->ed_fsz >= EI_NIDENT) && 151 (_elf_vm(elf, (size_t)0, (size_t)EI_NIDENT) == OK_YES) && 152 (base[EI_MAG0] == ELFMAG0) && 153 (base[EI_MAG1] == ELFMAG1) && 154 (base[EI_MAG2] == ELFMAG2) && 155 (base[EI_MAG3] == ELFMAG3)) { 156 elf->ed_kind = ELF_K_ELF; 157 elf->ed_class = base[EI_CLASS]; 158 elf->ed_encode = base[EI_DATA]; 159 if ((elf->ed_version = base[EI_VERSION]) == 0) 160 elf->ed_version = 1; 161 elf->ed_identsz = EI_NIDENT; 162 163 /* 164 * Allow writing only if originally specified read only. 165 * This is only necessary if the file must be translating 166 * from one encoding to another. 167 */ 168 ELFACCESSDATA(encode, _elf_encode) 169 if ((elf->ed_vm == 0) && ((elf->ed_myflags & EDF_WRITE) == 0) && 170 (elf->ed_encode != encode)) { 171 if (mprotect((char *)elf->ed_image, elf->ed_imagesz, 172 PROT_READ|PROT_WRITE) == -1) { 173 _elf_seterr(EIO_VM, errno); 174 return (0); 175 } 176 } 177 return (elf); 178 } 179 180 /* 181 * Determine if this is an Archive 182 */ 183 if ((elf->ed_fsz >= SARMAG) && 184 (_elf_vm(elf, (size_t)0, (size_t)SARMAG) == OK_YES) && 185 (memcmp(base, armag, SARMAG) == 0)) { 186 _elf_arinit(elf); 187 elf->ed_kind = ELF_K_AR; 188 elf->ed_identsz = SARMAG; 189 return (elf); 190 } 191 192 /* 193 * Return a few ident bytes, but not so many that 194 * getident() must read a large file. 512 is arbitrary. 195 */ 196 197 elf->ed_kind = ELF_K_NONE; 198 if ((elf->ed_identsz = elf->ed_fsz) > 512) 199 elf->ed_identsz = 512; 200 201 return (elf); 202 } 203 204 Elf * 205 elf_memory(char * image, size_t sz) 206 { 207 Elf *elf; 208 unsigned work; 209 210 /* 211 * version() no called yet? 212 */ 213 ELFACCESSDATA(work, _elf_work) 214 if (work == EV_NONE) { 215 _elf_seterr(ESEQ_VER, 0); 216 return (0); 217 } 218 219 if ((elf = (Elf *)calloc(1, sizeof (Elf))) == 0) { 220 _elf_seterr(EMEM_ELF, errno); 221 return (0); 222 } 223 NOTE(NOW_INVISIBLE_TO_OTHER_THREADS(*elf)) 224 elf->ed_fd = -1; 225 elf->ed_myflags |= EDF_READ | EDF_MEMORY; 226 elf->ed_image = elf->ed_ident = image; 227 elf->ed_imagesz = elf->ed_fsz = elf->ed_identsz = sz; 228 elf->ed_kind = ELF_K_ELF; 229 elf->ed_class = image[EI_CLASS]; 230 elf->ed_encode = image[EI_DATA]; 231 if ((elf->ed_version = image[EI_VERSION]) == 0) 232 elf->ed_version = 1; 233 elf->ed_identsz = EI_NIDENT; 234 elf->ed_activ = 1; 235 elf = _elf_config(elf); 236 NOTE(NOW_VISIBLE_TO_OTHER_THREADS(*elf)) 237 return (elf); 238 } 239 240 /* 241 * The following is a private interface between the linkers (ld & ld.so.1) 242 * and libelf. 243 * 244 * elf_begin(0, ELF_C_IMAGE, ref) 245 * Return a new elf_descriptor which uses the memory image from 246 * ref as the base image of the elf file. Before this elf_begin() 247 * is called an elf_update(ref, ELF_C_WRIMAGE) must have been 248 * done to the ref elf descriptor. 249 * The ELF_C_IMAGE is unique in that modificatino of the Elf structure 250 * is illegal (no elf_new*()) but you can modify the actual 251 * data image of the file in question. 252 * 253 * When you are done processing this file you can then perform a 254 * elf_end() on it. 255 * 256 * NOTE: if an elf_update(ref, ELF_C_WRITE) is done on the ref Elf 257 * descriptor then the memory image that the ELF_C_IMAGE 258 * is using has been discarded. The proper calling convention 259 * for this is as follows: 260 * 261 * elf1 = elf_begin(fd, ELF_C_WRITE, 0); 262 * ... 263 * elf_update(elf1, ELF_C_WRIMAGE); build memory image 264 * elf2 = elf_begin(0, ELF_C_IMAGE, elf1); 265 * ... 266 * elf_end(elf2); 267 * elf_updage(elf1, ELF_C_WRITE); flush memory image to disk 268 * elf_end(elf1); 269 * 270 * 271 * elf_begin(0, ELF_C_IMAGE, 0); 272 * returns a pointer to an elf descriptor as if it were opened 273 * with ELF_C_WRITE except that it has no file descriptor and it 274 * will not create a file. It's to be used with the command: 275 * 276 * elf_update(elf, ELF_C_WRIMAGE) 277 * 278 * which will build a memory image instead of a file image. 279 * The memory image is allocated via dynamic memory (malloc) and 280 * can be free with a subsequent call to 281 * 282 * elf_update(elf, ELF_C_WRITE) 283 * 284 * NOTE: that if elf_end(elf) is called it will not free the 285 * memory image if it is still allocated. It is then 286 * the callers responsiblity to free it via a call 287 * to free(). 288 * 289 * Here is a potential calling sequence for this interface: 290 * 291 * elf1 = elf_begin(0, ELF_C_IMAGE, 0); 292 * ... 293 * elf_update(elf1, ELF_C_WRIMAGE); build memory image 294 * elf2 = elf_begin(0, ELF_C_IMAGE, elf1); 295 * ... 296 * image_ptr = elf32_getehdr(elf2); get pointer to image 297 * elf_end(elf2); 298 * elf_end(elf1); 299 * ... 300 * use image 301 * ... 302 * free(image_ptr); 303 */ 304 305 Elf * 306 elf_begin(int fd, Elf_Cmd cmd, Elf *ref) 307 { 308 register Elf *elf; 309 unsigned work; 310 unsigned flags = 0; 311 312 ELFACCESSDATA(work, _elf_work) 313 if (work == EV_NONE) /* version() not called yet */ 314 { 315 _elf_seterr(ESEQ_VER, 0); 316 return (0); 317 } 318 switch (cmd) { 319 default: 320 _elf_seterr(EREQ_BEGIN, 0); 321 return (0); 322 323 case ELF_C_NULL: 324 return (0); 325 326 case ELF_C_IMAGE: 327 if (ref) { 328 char * image; 329 size_t imagesz; 330 ELFRLOCK(ref); 331 if ((image = ref->ed_wrimage) == 0) { 332 _elf_seterr(EREQ_NOWRIMAGE, 0); 333 ELFUNLOCK(ref); 334 return (0); 335 } 336 imagesz = ref->ed_wrimagesz; 337 ELFUNLOCK(ref); 338 return (elf_memory(image, imagesz)); 339 } 340 /* FALLTHROUGH */ 341 case ELF_C_WRITE: 342 if ((elf = (Elf *)calloc(1, sizeof (Elf))) == 0) { 343 _elf_seterr(EMEM_ELF, errno); 344 return (0); 345 } 346 NOTE(NOW_INVISIBLE_TO_OTHER_THREADS(*elf)) 347 ELFRWLOCKINIT(&elf->ed_rwlock); 348 elf->ed_fd = fd; 349 elf->ed_activ = 1; 350 elf->ed_myflags |= EDF_WRITE; 351 if (cmd == ELF_C_IMAGE) 352 elf->ed_myflags |= EDF_WRALLOC; 353 NOTE(NOW_VISIBLE_TO_OTHER_THREADS(*elf)) 354 return (elf); 355 case ELF_C_RDWR: 356 flags = EDF_WRITE | EDF_READ; 357 break; 358 359 case ELF_C_READ: 360 flags = EDF_READ; 361 break; 362 } 363 364 /* 365 * A null ref asks for a new file 366 * Non-null ref bumps the activation count 367 * or gets next archive member 368 */ 369 370 if (ref == 0) { 371 if ((elf = _elf_regular(fd, flags)) == 0) 372 return (0); 373 } else { 374 ELFWLOCK(ref); 375 if ((ref->ed_myflags & flags) != flags) { 376 _elf_seterr(EREQ_RDWR, 0); 377 ELFUNLOCK(ref); 378 return (0); 379 } 380 /* 381 * new activation ? 382 */ 383 if (ref->ed_kind != ELF_K_AR) { 384 ++ref->ed_activ; 385 ELFUNLOCK(ref); 386 return (ref); 387 } 388 if ((elf = _elf_member(fd, ref, flags)) == 0) { 389 ELFUNLOCK(ref); 390 return (0); 391 } 392 ELFUNLOCK(ref); 393 } 394 395 NOTE(NOW_INVISIBLE_TO_OTHER_THREADS(*elf)) 396 elf->ed_activ = 1; 397 elf = _elf_config(elf); 398 NOTE(NOW_VISIBLE_TO_OTHER_THREADS(*elf)) 399 400 return (elf); 401 } 402