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