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 (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright (c) 1988 AT&T 24 * All Rights Reserved 25 * 26 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 27 * Use is subject to license terms. 28 */ 29 30 /* 31 * Processing of relocatable objects and shared objects. 32 */ 33 34 /* 35 * ld -- link/editor main program 36 */ 37 #include <sys/types.h> 38 #include <sys/time.h> 39 #include <sys/mman.h> 40 #include <string.h> 41 #include <stdio.h> 42 #include <locale.h> 43 #include <stdarg.h> 44 #include <debug.h> 45 #include "msg.h" 46 #include "_libld.h" 47 48 /* 49 * All target specific code is referenced via this global variable, which 50 * is initialized in ld_main(). This allows the linker to function as 51 * a cross linker, by vectoring to the target-specific code for the 52 * current target machine. 53 */ 54 Target ld_targ; 55 56 /* 57 * A default library search path is used if one was not supplied on the command 58 * line. Note: these strings can not use MSG_ORIG() since they are modified as 59 * part of the path processing. 60 */ 61 #if defined(_ELF64) 62 static char def_Plibpath[] = "/lib/64:/usr/lib/64"; 63 #else 64 static char def_Plibpath[] = "/usr/ccs/lib:/lib:/usr/lib"; 65 #endif 66 67 /* 68 * A default elf header provides for simplifying diagnostic processing. 69 */ 70 static Ehdr def_ehdr = { { ELFMAG0, ELFMAG1, ELFMAG2, ELFMAG3, 71 ELFCLASSNONE, ELFDATANONE }, 0, EM_NONE, 72 EV_CURRENT }; 73 74 /* 75 * Establish the global state necessary to link the desired machine 76 * target, as reflected by the ld_targ global variable. 77 */ 78 int 79 ld_init_target(Lm_list *lml, Half mach) 80 { 81 switch (mach) { 82 case EM_386: 83 case EM_AMD64: 84 ld_targ = *ld_targ_init_x86(); 85 break; 86 87 case EM_SPARC: 88 case EM_SPARC32PLUS: 89 case EM_SPARCV9: 90 ld_targ = *ld_targ_init_sparc(); 91 break; 92 93 default: 94 { 95 Conv_inv_buf_t inv_buf; 96 97 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_TARG_UNSUPPORTED), 98 conv_ehdr_mach(mach, 0, &inv_buf)); 99 return (1); 100 } 101 } 102 103 return (0); 104 } 105 106 107 /* 108 * The main program 109 */ 110 int 111 ld_main(int argc, char **argv, Half mach) 112 { 113 char *sgs_support; /* SGS_SUPPORT environment string */ 114 Half etype; 115 Ofl_desc *ofl; 116 117 /* 118 * Establish a base time. Total time diagnostics are relative to 119 * entering the link-editor here. 120 */ 121 (void) gettimeofday(&DBG_TOTALTIME, NULL); 122 DBG_DELTATIME = DBG_TOTALTIME; 123 124 /* 125 * Initialize signal handlers, and output file variables. Establish a 126 * default output ELF header to satisfy diagnostic requirements. 127 */ 128 if ((ofl = libld_calloc(1, sizeof (Ofl_desc))) == 0) 129 return (1); 130 131 /* Initilize target state */ 132 if (ld_init_target(NULL, mach) != 0) 133 return (1); 134 135 /* 136 * Set up the output ELF header, and initialize the machine 137 * and class details. 138 */ 139 ofl->ofl_dehdr = &def_ehdr; 140 def_ehdr.e_ident[EI_CLASS] = ld_targ.t_m.m_class; 141 def_ehdr.e_ident[EI_DATA] = ld_targ.t_m.m_data; 142 def_ehdr.e_machine = ld_targ.t_m.m_mach; 143 144 ld_init(ofl); 145 146 /* 147 * Build up linker version string 148 */ 149 if ((ofl->ofl_sgsid = (char *)libld_calloc(MSG_SGS_ID_SIZE + 150 strlen(link_ver_string) + 1, 1)) == NULL) 151 return (1); 152 (void) strcpy(ofl->ofl_sgsid, MSG_ORIG(MSG_SGS_ID)); 153 (void) strcat(ofl->ofl_sgsid, link_ver_string); 154 155 /* 156 * Argument pass one. Get all the input flags (skip any files) and 157 * check for consistency. Return from ld_process_flags() marks the 158 * end of mapfile processing. The entrance criteria and segment 159 * descriptors are complete and in their final form. 160 */ 161 if (ld_process_flags(ofl, argc, argv) == S_ERROR) 162 return (1); 163 if (ofl->ofl_flags & FLG_OF_FATAL) { 164 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_ARG_FLAGS)); 165 return (1); 166 } 167 168 /* 169 * At this point a call such as ld -V is considered complete. 170 */ 171 if (ofl->ofl_flags1 & FLG_OF1_DONE) 172 return (0); 173 174 /* 175 * Determine whether any support libraries should be loaded, 176 * (either through the SGS_SUPPORT environment variable and/or 177 * through the -S option). 178 */ 179 #if defined(_LP64) 180 if ((sgs_support = getenv(MSG_ORIG(MSG_SGS_SUPPORT_64))) == NULL) 181 #else 182 if ((sgs_support = getenv(MSG_ORIG(MSG_SGS_SUPPORT_32))) == NULL) 183 #endif 184 sgs_support = getenv(MSG_ORIG(MSG_SGS_SUPPORT)); 185 186 if (sgs_support && (*sgs_support != '\0')) { 187 const char *sep = MSG_ORIG(MSG_STR_COLON); 188 char *lib; 189 char *lasts; 190 191 DBG_CALL(Dbg_support_req(ofl->ofl_lml, sgs_support, 192 DBG_SUP_ENVIRON)); 193 if ((lib = strtok_r(sgs_support, sep, &lasts)) != NULL) { 194 do { 195 if (ld_sup_loadso(ofl, lib) == S_ERROR) 196 return (ld_exit(ofl)); 197 DBG_CALL(Dbg_util_nl(ofl->ofl_lml, DBG_NL_STD)); 198 199 } while ((lib = strtok_r(NULL, sep, &lasts)) != NULL); 200 } 201 } 202 if (lib_support) { 203 Aliste idx; 204 char *lib; 205 206 for (APLIST_TRAVERSE(lib_support, idx, lib)) { 207 DBG_CALL(Dbg_support_req(ofl->ofl_lml, lib, 208 DBG_SUP_CMDLINE)); 209 if (ld_sup_loadso(ofl, lib) == S_ERROR) 210 return (ld_exit(ofl)); 211 DBG_CALL(Dbg_util_nl(ofl->ofl_lml, DBG_NL_STD)); 212 } 213 } 214 215 DBG_CALL(Dbg_ent_print(ofl->ofl_lml, 216 ofl->ofl_dehdr->e_ident[EI_OSABI], ofl->ofl_dehdr->e_machine, 217 ofl->ofl_ents, (ofl->ofl_flags & FLG_OF_DYNAMIC) != 0)); 218 DBG_CALL(Dbg_seg_list(ofl->ofl_lml, 219 ofl->ofl_dehdr->e_ident[EI_OSABI], ofl->ofl_dehdr->e_machine, 220 ofl->ofl_segs)); 221 222 /* 223 * The objscnt and soscnt variables were used to estimate the expected 224 * input files, and size the symbol hash buckets accordingly. Reset 225 * these values now, so as to gain an accurate count from pass two, for 226 * later statistics diagnostics. 227 */ 228 ofl->ofl_objscnt = ofl->ofl_soscnt = 0; 229 230 /* 231 * Determine whether we can create the file before going any further. 232 */ 233 if (ld_open_outfile(ofl) == S_ERROR) 234 return (ld_exit(ofl)); 235 236 /* 237 * If the user didn't supply a library path supply a default. And, if 238 * no run-path has been specified (-R), see if the environment variable 239 * is in use (historic). 240 */ 241 if (Plibpath == NULL) 242 Plibpath = def_Plibpath; 243 244 if (ofl->ofl_rpath == NULL) { 245 char *rpath; 246 if (((rpath = getenv(MSG_ORIG(MSG_LD_RUN_PATH))) != NULL) && 247 (strcmp((const char *)rpath, MSG_ORIG(MSG_STR_EMPTY)))) 248 ofl->ofl_rpath = rpath; 249 } 250 251 /* 252 * Argument pass two. Input all libraries and objects. 253 */ 254 if (ld_lib_setup(ofl) == S_ERROR) 255 return (ld_exit(ofl)); 256 257 /* 258 * Call ld_start() with the etype of our output file and the 259 * output file name. 260 */ 261 if (ofl->ofl_flags & FLG_OF_SHAROBJ) 262 etype = ET_DYN; 263 else if (ofl->ofl_flags & FLG_OF_RELOBJ) 264 etype = ET_REL; 265 else 266 etype = ET_EXEC; 267 268 ld_sup_start(ofl, etype, argv[0]); 269 270 /* 271 * Process all input files. 272 */ 273 if (ld_process_files(ofl, argc, argv) == S_ERROR) 274 return (ld_exit(ofl)); 275 if (ofl->ofl_flags & FLG_OF_FATAL) { 276 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_ARG_FILES), 277 ofl->ofl_name); 278 return (ld_exit(ofl)); 279 } 280 281 ld_sup_input_done(ofl); 282 283 /* 284 * Now that all input section processing is complete, validate and 285 * process any SHT_SUNW_move sections. 286 */ 287 if (ofl->ofl_ismove && (ld_process_move(ofl) == S_ERROR)) 288 return (ld_exit(ofl)); 289 290 /* 291 * Before validating all symbols count the number of relocation entries. 292 * If copy relocations exist, COMMON symbols must be generated which are 293 * assigned to the executables .bss. During sym_validate() the actual 294 * size and alignment of the .bss is calculated. Doing things in this 295 * order reduces the number of symbol table traversals required (however 296 * it does take a little longer for the user to be told of any undefined 297 * symbol errors). 298 */ 299 if (ld_reloc_init(ofl) == S_ERROR) 300 return (ld_exit(ofl)); 301 302 /* 303 * Now that all symbol processing is complete see if any undefined 304 * references still remain. If we observed undefined symbols the 305 * FLG_OF_FATAL bit will be set: If creating a static executable, or a 306 * dynamic executable or shared object with the -zdefs flag set, this 307 * condition is fatal. If creating a shared object with the -Bsymbolic 308 * flag set, this condition is simply a warning. 309 */ 310 if (ld_sym_validate(ofl) == S_ERROR) 311 return (ld_exit(ofl)); 312 313 if (ofl->ofl_flags1 & FLG_OF1_OVRFLW) { 314 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_ARG_FILES), 315 ofl->ofl_name); 316 return (ld_exit(ofl)); 317 } else if (ofl->ofl_flags & FLG_OF_FATAL) { 318 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_ARG_SYM_FATAL), 319 ofl->ofl_name); 320 return (ld_exit(ofl)); 321 } else if (ofl->ofl_flags & FLG_OF_WARN) 322 eprintf(ofl->ofl_lml, ERR_WARNING, MSG_INTL(MSG_ARG_SYM_WARN)); 323 324 /* 325 * Generate any necessary sections. 326 */ 327 if (ld_make_sections(ofl) == S_ERROR) 328 return (ld_exit(ofl)); 329 330 /* 331 * Now that all sections have been added to the output file, determine 332 * whether any mapfile section ordering was specified, and verify that 333 * all mapfile ordering directives have been matched. Issue a warning 334 * for any directives that have not been matched. 335 * Also, if SHF_ORDERED sections exist, set up sort key values. 336 */ 337 if (ofl->ofl_flags & (FLG_OF_SECORDER | FLG_OF_KEY)) 338 ld_sec_validate(ofl); 339 340 /* 341 * Having collected all the input data create the initial output file 342 * image, assign virtual addresses to the image, and generate a load 343 * map if the user requested one. 344 */ 345 if (ld_create_outfile(ofl) == S_ERROR) 346 return (ld_exit(ofl)); 347 348 if (ld_update_outfile(ofl) == S_ERROR) 349 return (ld_exit(ofl)); 350 if (ofl->ofl_flags & FLG_OF_GENMAP) 351 ld_map_out(ofl); 352 353 /* 354 * Build relocation sections and perform any relocation updates. 355 */ 356 if (ld_reloc_process(ofl) == S_ERROR) 357 return (ld_exit(ofl)); 358 359 /* 360 * Fill in contents for unwind header (.eh_frame_hdr) 361 */ 362 if (ld_unwind_populate_hdr(ofl) == S_ERROR) 363 return (ld_exit(ofl)); 364 365 /* 366 * Finally create the files elf checksum. 367 */ 368 if (ofl->ofl_checksum) 369 *ofl->ofl_checksum = (Xword)elf_checksum(ofl->ofl_elf); 370 371 /* 372 * If this is a cross link to a target with a different byte 373 * order than the linker, swap the data to the target byte order. 374 */ 375 if (((ofl->ofl_flags1 & FLG_OF1_ENCDIFF) != 0) && 376 (_elf_swap_wrimage(ofl->ofl_elf) != 0)) { 377 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_SWAP_WRIMAGE), 378 ofl->ofl_name); 379 return (ld_exit(ofl)); 380 } 381 382 /* 383 * We're done, so make sure the updates are flushed to the output file. 384 */ 385 if ((ofl->ofl_size = elf_update(ofl->ofl_welf, ELF_C_WRITE)) == 0) { 386 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_UPDATE), 387 ofl->ofl_name); 388 return (ld_exit(ofl)); 389 } 390 391 ld_sup_atexit(ofl, 0); 392 393 DBG_CALL(Dbg_statistics_ld(ofl)); 394 DBG_CALL(Dbg_basic_finish(ofl->ofl_lml)); 395 396 /* 397 * Wrap up debug output file if one is open 398 */ 399 dbg_cleanup(); 400 401 /* 402 * For performance reasons we don't actually free up the memory we've 403 * allocated, it will be freed when we exit. 404 * 405 * But the below line can be uncommented if/when we want to measure how 406 * our memory consumption and freeing are doing. We should be able to 407 * free all the memory that has been allocated as part of the link-edit 408 * process. 409 * 410 * ofl_cleanup(ofl); 411 */ 412 return (0); 413 } 414 415 /* 416 * Cleanup an Ifl_desc. 417 */ 418 static void 419 ifl_list_cleanup(APlist *apl) 420 { 421 Aliste idx; 422 Ifl_desc *ifl; 423 424 for (APLIST_TRAVERSE(apl, idx, ifl)) { 425 if (ifl->ifl_elf) 426 (void) elf_end(ifl->ifl_elf); 427 } 428 } 429 430 /* 431 * Cleanup all memory that has been dynamically allocated during libld 432 * processing and elf_end() all Elf descriptors that are still open. 433 */ 434 void 435 ld_ofl_cleanup(Ofl_desc *ofl) 436 { 437 Ld_heap *chp, *php; 438 Ar_desc *adp; 439 Aliste idx; 440 441 ifl_list_cleanup(ofl->ofl_objs); 442 ofl->ofl_objs = NULL; 443 ifl_list_cleanup(ofl->ofl_sos); 444 ofl->ofl_sos = NULL; 445 446 for (APLIST_TRAVERSE(ofl->ofl_ars, idx, adp)) { 447 Ar_aux *aup; 448 Elf_Arsym *arsym; 449 450 for (arsym = adp->ad_start, aup = adp->ad_aux; 451 arsym->as_name; ++arsym, ++aup) { 452 if ((aup->au_mem) && (aup->au_mem != FLG_ARMEM_PROC)) { 453 (void) elf_end(aup->au_mem->am_elf); 454 455 /* 456 * Null out all entries to this member so 457 * that we don't attempt to elf_end() it again. 458 */ 459 ld_ar_member(adp, arsym, aup, 0); 460 } 461 } 462 (void) elf_end(adp->ad_elf); 463 } 464 ofl->ofl_ars = NULL; 465 466 (void) elf_end(ofl->ofl_elf); 467 (void) elf_end(ofl->ofl_welf); 468 469 for (chp = ld_heap, php = NULL; chp; php = chp, chp = chp->lh_next) { 470 if (php) 471 (void) munmap((void *)php, 472 (size_t)php->lh_end - (size_t)php); 473 } 474 if (php) 475 (void) munmap((void *)php, (size_t)php->lh_end - (size_t)php); 476 477 ld_heap = NULL; 478 } 479