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) 1992, 2010, Oracle and/or its affiliates. All rights reserved. 24 */ 25 26 /* 27 * Object file dependent suport for ELF objects. 28 */ 29 30 #include <sys/mman.h> 31 #include <stdio.h> 32 #include <unistd.h> 33 #include <libelf.h> 34 #include <string.h> 35 #include <dlfcn.h> 36 #include <debug.h> 37 #include <libld.h> 38 #include "_rtld.h" 39 #include "_audit.h" 40 #include "_elf.h" 41 42 static Rt_map *olmp = NULL; 43 static Alist *mpalp = NULL; 44 45 static Ehdr dehdr = { { ELFMAG0, ELFMAG1, ELFMAG2, ELFMAG3, 46 M_CLASS, M_DATA }, 0, M_MACH, EV_CURRENT }; 47 48 /* 49 * Process a relocatable object. The static object link map pointer is used as 50 * a flag to determine whether a concatenation is already in progress (ie. an 51 * LD_PRELOAD may specify a list of objects). The link map returned simply 52 * specifies an `object' flag which the caller can interpret and thus call 53 * elf_obj_fini() to complete the concatenation. 54 */ 55 static Rt_map * 56 elf_obj_init(Lm_list *lml, Aliste lmco, const char *oname) 57 { 58 Ofl_desc *ofl; 59 const char *name; 60 size_t lmsz; 61 62 /* 63 * Allocate the name of this object, as the original name may be 64 * associated with a data buffer that can be reused to load the 65 * dependencies needed to processes this object. 66 */ 67 if ((name = stravl_insert(oname, 0, 0, 0)) == NULL) 68 return (NULL); 69 70 /* 71 * Initialize an output file descriptor and the entrance criteria. 72 */ 73 if ((ofl = calloc(sizeof (Ofl_desc), 1)) == NULL) 74 return (NULL); 75 76 ofl->ofl_dehdr = &dehdr; 77 78 ofl->ofl_flags = (FLG_OF_DYNAMIC | FLG_OF_SHAROBJ | FLG_OF_STRIP); 79 ofl->ofl_flags1 = (FLG_OF1_RELDYN | FLG_OF1_TEXTOFF | FLG_OF1_MEMORY); 80 ofl->ofl_lml = lml; 81 82 /* 83 * As ent_setup() will effectively lazy load the necessary support 84 * libraries, make sure ld.so.1 is initialized for plt relocations. 85 * Then configure libld.so to process objects of the desired target 86 * type (this is the first call to libld.so, which will effectively 87 * lazyload it). 88 */ 89 if ((elf_rtld_load() == 0) || (ld_init_target(lml, M_MACH) != 0)) { 90 free(ofl); 91 return (NULL); 92 } 93 94 /* 95 * Obtain a generic set of entrance criteria, and generate a link map 96 * place holder and use the ELFPRV() element to maintain the output 97 * file descriptor. 98 */ 99 lmsz = S_DROUND(sizeof (Rt_map)) + sizeof (Rt_elfp); 100 if ((ld_ent_setup(ofl, syspagsz) == S_ERROR) || 101 ((olmp = calloc(lmsz, 1)) == NULL)) { 102 free(ofl); 103 return (NULL); 104 } 105 106 DBG_CALL(Dbg_file_elf(lml, name, 0, 0, lml->lm_lmidstr, lmco)); 107 FLAGS(olmp) |= FLG_RT_OBJECT; 108 ELFPRV(olmp) = (void *)ofl; 109 110 /* 111 * Initialize string tables. 112 */ 113 if (ld_init_strings(ofl) == S_ERROR) { 114 free(ofl); 115 free(olmp); 116 olmp = NULL; 117 return (NULL); 118 } 119 120 /* 121 * Assign the output file name to be the initial object that got us 122 * here. This name is being used for diagnostic purposes only as we 123 * don't actually generate an output file unless debugging is enabled. 124 */ 125 ofl->ofl_name = name; 126 NAME(olmp) = (char *)name; 127 LIST(olmp) = lml; 128 129 lm_append(lml, lmco, olmp); 130 return (olmp); 131 } 132 133 /* 134 * Define a structure to retain the mapping information of the original 135 * relocatable object. Typically, mmapobj(2) maps a relocatable object into one 136 * mapping. However, if padding has been enabled by a debugger, then additional 137 * padding segments may have been added. elf_obj_file() needs to know which 138 * segment is the relocatable objects data, and retain the initial segment and 139 * the associated segment number for unmapping this object later (see 140 * elf_obj_fini()). Note, even if padding is enabled, the final shared object 141 * that is created by the link-editor for this relocatable object will have no 142 * associated padding, as ld(1) has no capabilities to provide padding. 143 */ 144 typedef struct { 145 mmapobj_result_t *md_mpp; 146 uint_t md_mnum; 147 } Mmap_desc; 148 149 /* 150 * Initial processing of a relocatable object. If this is the first object 151 * encountered we need to initialize some structures, then simply call the 152 * link-edit functionality to provide the initial processing of the file (ie. 153 * reads in sections and symbols, performs symbol resolution if more that one 154 * object file have been specified, and assigns input sections to output 155 * sections). 156 */ 157 Rt_map * 158 elf_obj_file(Lm_list *lml, Aliste lmco, Rt_map *clmp, const char *name, 159 mmapobj_result_t *hmpp, mmapobj_result_t *mpp, uint_t mnum) 160 { 161 Rej_desc rej; 162 Mmap_desc md; 163 164 /* 165 * If this is the first relocatable object (LD_PRELOAD could provide a 166 * list of objects), initialize an input file descriptor and a link map. 167 */ 168 if ((olmp == NULL) && ((olmp = elf_obj_init(lml, lmco, name)) == NULL)) 169 return (NULL); 170 171 DBG_CALL(Dbg_util_nl(lml, DBG_NL_STD)); 172 173 /* 174 * Keep track of the input image, as this must be free'd after all ELF 175 * processing is completed. 176 */ 177 md.md_mpp = mpp; 178 md.md_mnum = mnum; 179 if (alist_append(&mpalp, &md, sizeof (Mmap_desc), 180 AL_CNT_MPOBJS) == NULL) { 181 remove_so(lml, olmp, clmp); 182 return (NULL); 183 } 184 185 /* 186 * Pass the object mapping to the link-editor to commence processing the 187 * file. 188 */ 189 if (ld_process_mem(name, name, hmpp->mr_addr, hmpp->mr_msize, 190 (Ofl_desc *)ELFPRV(olmp), &rej) == (Ifl_desc *)S_ERROR) { 191 remove_so(lml, olmp, clmp); 192 return (NULL); 193 } 194 195 return (olmp); 196 } 197 198 /* 199 * Ensure any platform or machine capability names are valid. 200 */ 201 inline static int 202 check_plat_names(Syscapset *scapset, Alist *caps, Rej_desc *rej) 203 { 204 Capstr *capstr; 205 Aliste idx; 206 207 for (ALIST_TRAVERSE(caps, idx, capstr)) { 208 if (platcap_check(scapset, capstr->cs_str, rej) == 1) 209 return (1); 210 } 211 return (0); 212 } 213 214 inline static int 215 check_mach_names(Syscapset *scapset, Alist *caps, Rej_desc *rej) 216 { 217 Capstr *capstr; 218 Aliste idx; 219 220 for (ALIST_TRAVERSE(caps, idx, capstr)) { 221 if (machcap_check(scapset, capstr->cs_str, rej) == 1) 222 return (1); 223 } 224 return (0); 225 } 226 227 /* 228 * Finish relocatable object processing. Having already initially processed one 229 * or more objects, complete the generation of a shared object image by calling 230 * the appropriate link-edit functionality (refer to sgs/ld/common/main.c). 231 */ 232 Rt_map * 233 elf_obj_fini(Lm_list *lml, Rt_map *lmp, Rt_map *clmp, int *in_nfavl) 234 { 235 Ofl_desc *ofl = (Ofl_desc *)ELFPRV(lmp); 236 Rt_map *nlmp, *tlmp; 237 Ehdr *ehdr; 238 Phdr *phdr; 239 mmapobj_result_t *mpp, *hmpp; 240 uint_t phnum; 241 int mnum; 242 Lm_cntl *lmc; 243 Aliste idx1; 244 Mmap_desc *mdp; 245 Fdesc fd = { 0 }; 246 Grp_hdl *ghp; 247 Rej_desc rej = { 0 }; 248 Syscapset *scapset; 249 elfcap_mask_t omsk; 250 Alist *oalp; 251 252 DBG_CALL(Dbg_util_nl(lml, DBG_NL_STD)); 253 254 if (ld_reloc_init(ofl) == S_ERROR) 255 return (NULL); 256 if (ld_sym_validate(ofl) == S_ERROR) 257 return (NULL); 258 259 /* 260 * At this point, all input section processing is complete. If any 261 * capabilities have been established, ensure that they are appropriate 262 * for this system. 263 */ 264 if (pnavl_recorded(&capavl, ofl->ofl_name, 0, NULL)) 265 scapset = alt_scapset; 266 else 267 scapset = org_scapset; 268 269 if ((((omsk = ofl->ofl_ocapset.oc_hw_1.cm_val) != 0) && 270 (hwcap1_check(scapset, omsk, &rej) == 0)) || 271 (((omsk = ofl->ofl_ocapset.oc_sf_1.cm_val) != 0) && 272 (sfcap1_check(scapset, omsk, &rej) == 0)) || 273 (((omsk = ofl->ofl_ocapset.oc_hw_2.cm_val) != 0) && 274 (hwcap2_check(scapset, omsk, &rej) == 0)) || 275 (((oalp = ofl->ofl_ocapset.oc_plat.cl_val) != NULL) && 276 (check_plat_names(scapset, oalp, &rej) == 0)) || 277 (((oalp = ofl->ofl_ocapset.oc_mach.cl_val) != NULL) && 278 (check_mach_names(scapset, oalp, &rej) == 0))) { 279 if ((lml_main.lm_flags & LML_FLG_TRC_LDDSTUB) && lmp && 280 (FLAGS1(lmp) & FL1_RT_LDDSTUB) && (NEXT(lmp) == NULL)) { 281 /* LINTED */ 282 (void) printf(MSG_INTL(ldd_reject[rej.rej_type]), 283 ofl->ofl_name, rej.rej_str); 284 } 285 return (NULL); 286 } 287 288 /* 289 * Finish creating the output file. 290 */ 291 if (ld_make_sections(ofl) == S_ERROR) 292 return (NULL); 293 if (ld_create_outfile(ofl) == S_ERROR) 294 return (NULL); 295 if (ld_update_outfile(ofl) == S_ERROR) 296 return (NULL); 297 if (ld_reloc_process(ofl) == S_ERROR) 298 return (NULL); 299 300 /* 301 * At this point we have a memory image of the shared object. The link 302 * editor would normally simply write this to the required output file. 303 * If we're debugging generate a standard temporary output file. 304 */ 305 DBG_CALL(Dbg_file_output(ofl)); 306 307 /* 308 * Allocate a mapping array to retain mapped segment information. 309 */ 310 ehdr = ofl->ofl_nehdr; 311 phdr = ofl->ofl_phdr; 312 313 if ((mpp = hmpp = calloc(ehdr->e_phnum, 314 sizeof (mmapobj_result_t))) == NULL) 315 return (NULL); 316 for (mnum = 0, phnum = 0; phnum < ehdr->e_phnum; phnum++) { 317 if (phdr[phnum].p_type != PT_LOAD) 318 continue; 319 320 mpp[mnum].mr_addr = (caddr_t)((uintptr_t)phdr[phnum].p_vaddr + 321 (uintptr_t)ehdr); 322 mpp[mnum].mr_msize = phdr[phnum].p_memsz; 323 mpp[mnum].mr_fsize = phdr[phnum].p_filesz; 324 mpp[mnum].mr_prot = (PROT_READ | PROT_WRITE | PROT_EXEC); 325 mnum++; 326 } 327 328 /* 329 * Generate a new link map representing the memory image created. 330 */ 331 fd.fd_nname = ofl->ofl_name; 332 if ((nlmp = elf_new_lmp(lml, CNTL(olmp), &fd, (Addr)hmpp->mr_addr, 333 ofl->ofl_size, NULL, clmp, in_nfavl)) == NULL) 334 return (NULL); 335 336 MMAPS(nlmp) = hmpp; 337 MMAPCNT(nlmp) = mnum; 338 PADSTART(nlmp) = (ulong_t)hmpp->mr_addr; 339 PADIMLEN(nlmp) = mpp->mr_addr + mpp->mr_msize - hmpp->mr_addr; 340 341 /* 342 * Replace the original (temporary) link map with the new link map. 343 */ 344 /* LINTED */ 345 lmc = (Lm_cntl *)alist_item_by_offset(lml->lm_lists, CNTL(nlmp)); 346 lml->lm_obj--; 347 348 if ((tlmp = PREV_RT_MAP(nlmp)) == olmp) 349 tlmp = nlmp; 350 351 if (PREV(olmp)) { 352 NEXT(PREV_RT_MAP(olmp)) = (Link_map *)nlmp; 353 PREV(nlmp) = PREV(olmp); 354 } else { 355 PREV(nlmp) = NULL; 356 lmc->lc_head = nlmp; 357 if (CNTL(nlmp) == ALIST_OFF_DATA) 358 lml->lm_head = nlmp; 359 } 360 361 if (NEXT(olmp) != (Link_map *)nlmp) { 362 NEXT(nlmp) = NEXT(olmp); 363 PREV(NEXT_RT_MAP(olmp)) = (Link_map *)nlmp; 364 } 365 366 NEXT(tlmp) = NULL; 367 368 lmc->lc_tail = tlmp; 369 if (CNTL(nlmp) == ALIST_OFF_DATA) 370 lml->lm_tail = tlmp; 371 372 HANDLES(nlmp) = HANDLES(olmp); 373 GROUPS(nlmp) = GROUPS(olmp); 374 STDEV(nlmp) = STDEV(olmp); 375 STINO(nlmp) = STINO(olmp); 376 377 FLAGS(nlmp) |= ((FLAGS(olmp) & ~FLG_RT_OBJECT) | FLG_RT_IMGALLOC); 378 FLAGS1(nlmp) |= FLAGS1(olmp); 379 MODE(nlmp) |= MODE(olmp); 380 381 NAME(nlmp) = NAME(olmp); 382 383 /* 384 * Reassign any original handles to the new link-map. 385 */ 386 for (APLIST_TRAVERSE(HANDLES(nlmp), idx1, ghp)) { 387 Grp_desc *gdp; 388 Aliste idx2; 389 390 ghp->gh_ownlmp = nlmp; 391 392 for (ALIST_TRAVERSE(ghp->gh_depends, idx2, gdp)) { 393 if (gdp->gd_depend == olmp) { 394 gdp->gd_depend = nlmp; 395 break; 396 } 397 } 398 } 399 400 ld_ofl_cleanup(ofl); 401 free(ELFPRV(olmp)); 402 free(olmp); 403 olmp = 0; 404 405 /* 406 * Unmap the original relocatable object. 407 */ 408 for (ALIST_TRAVERSE(mpalp, idx1, mdp)) { 409 unmap_obj(mdp->md_mpp, mdp->md_mnum); 410 free(mdp->md_mpp); 411 } 412 free(mpalp); 413 mpalp = NULL; 414 415 /* 416 * Now that we've allocated our permanent link map structure, expand the 417 * PATHNAME() and insert this path name into the FullPathNode AVL tree. 418 */ 419 (void) fullpath(nlmp, 0); 420 if (fpavl_insert(lml, nlmp, PATHNAME(nlmp), 0) == 0) 421 return (NULL); 422 423 /* 424 * If we're being audited tell the audit library of the file we've just 425 * opened. 426 */ 427 if ((lml->lm_tflags | AFLAGS(nlmp)) & LML_TFLG_AUD_MASK) { 428 if (audit_objopen(nlmp, nlmp) == 0) 429 return (NULL); 430 } 431 return (nlmp); 432 } 433