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) 1995, 2010, Oracle and/or its affiliates. All rights reserved. 24 */ 25 #ifndef _RTLD_H 26 #define _RTLD_H 27 28 /* 29 * Global include file for the runtime linker. 30 */ 31 #include <sys/mman.h> 32 #include <time.h> 33 #include <sgs.h> 34 #include <thread.h> 35 #include <synch.h> 36 #include <link.h> 37 #include <sys/avl.h> 38 #include <alist.h> 39 #include <libc_int.h> 40 #include <elfcap.h> 41 42 #ifdef _SYSCALL32 43 #include <inttypes.h> 44 #endif 45 46 #ifdef __cplusplus 47 extern "C" { 48 #endif 49 50 /* 51 * We use rtld_ino_t instead of ino_t so that we can get 52 * access to large inode values from 32-bit code. 53 */ 54 #ifdef _LP64 55 typedef ino_t rtld_ino_t; 56 #else 57 typedef ino64_t rtld_ino_t; 58 #endif 59 60 typedef struct rt_map Rt_map; 61 typedef struct slookup Slookup; 62 typedef struct sresult Sresult; 63 64 /* 65 * A binding descriptor. Establishes the binding relationship between two 66 * objects, the caller (originator) and the dependency (destination). 67 * 68 * Every relationship between two objects is tracked by a binding descriptor. 69 * This descriptor is referenced from a link-map's DEPENDS and CALLERS lists. 70 * Note, Aplist's are diagramed to fully expose the allocations required to 71 * establish the data structure relationships. 72 * 73 * Bnd_desc 74 * ---------- 75 * ------------| b_caller | 76 * | | b_depend | ---------- 77 * | | | | 78 * Rt_map | ---------- | Rt_map 79 * ---------- | ^ ^ | ---------- 80 * | | <-- | | --> | | 81 * | | -------- | | | | 82 * | DEPENDS | ----> | | | | -------- | | 83 * | | | | | | | | <---- | CALLERS | 84 * | | | | --- | | | | | 85 * | | | | --- | | | | 86 * | | -------- | | | | 87 * ---------- Aplist -------- ---------- 88 * Aplist 89 */ 90 typedef struct { 91 Rt_map *b_caller; /* caller (originator) of a binding */ 92 Rt_map *b_depend; /* dependency (destination) of a */ 93 /* binding */ 94 uint_t b_flags; /* relationship of caller to the */ 95 /* dependency */ 96 } Bnd_desc; 97 98 #define BND_NEEDED 0x0001 /* caller NEEDED the dependency */ 99 #define BND_REFER 0x0002 /* caller relocation references the */ 100 /* dependency */ 101 #define BND_FILTER 0x0004 /* binding identifies filter, used */ 102 /* for diagnostics only */ 103 /* 104 * Private structure for communication between rtld_db and rtld. 105 * 106 * We must bump the version number when ever an update in one of the 107 * structures/fields that rtld_db reads is updated. This hopefully permits 108 * rtld_db implementations of the future to recognize core files produced on 109 * older systems and deal with these core files accordingly. 110 * 111 * As of version 'R_RTLDDB_VERSION <= 2' the following fields were valid for 112 * core file examination (basically the public Link_map): 113 * 114 * ADDR() 115 * NAME() 116 * DYN() 117 * NEXT() 118 * PREV() 119 * 120 * Valid fields for R_RTLDDB_VERSION3 121 * 122 * PATHNAME() 123 * PADSTART() 124 * PADIMLEN() 125 * MSIZE() 126 * FLAGS() 127 * FLAGS1() 128 * 129 * Valid fields for R_RTLDDB_VERSION4 130 * 131 * TLSMODID() 132 * 133 * Valid fields for R_RTLDDB_VERSION5 134 * 135 * Added rtld_flags & FLG_RT_RELOCED to stable flags range 136 * 137 * Valid fields for R_RTLDDB_VERSION6 138 * 139 * rtd_dynlmlst converted from a List to APlist 140 */ 141 #define R_RTLDDB_VERSION1 1 /* base version level - used for core */ 142 /* file examination */ 143 #define R_RTLDDB_VERSION2 2 /* minor revision - not relevant for */ 144 /* core files */ 145 #define R_RTLDDB_VERSION3 3 146 #define R_RTLDDB_VERSION4 4 147 #define R_RTLDDB_VERSION5 5 148 #define R_RTLDDB_VERSION6 6 149 #define R_RTLDDB_VERSION R_RTLDDB_VERSION6 /* current version */ 150 151 typedef struct rtld_db_priv { 152 struct r_debug rtd_rdebug; /* original r_debug structure */ 153 Word rtd_version; /* version no. */ 154 size_t rtd_objpad; /* padding around mmap()ed objects */ 155 APlist **rtd_dynlmlst; /* pointer to dynlm_list pointer */ 156 } Rtld_db_priv; 157 158 #ifdef _SYSCALL32 159 typedef struct rtld_db_priv32 { 160 struct r_debug32 rtd_rdebug; /* original r_debug structure */ 161 Elf32_Word rtd_version; /* version no. */ 162 Elf32_Word rtd_objpad; /* padding around mmap()ed objects */ 163 Elf32_Addr rtd_dynlmlst; /* pointer to dynlm_list */ 164 } Rtld_db_priv32; 165 #endif /* _SYSCALL32 */ 166 167 /* 168 * External function definitions. ld.so.1 must convey information to libc in 169 * regards to threading. libc also provides routines for atexit() and message 170 * localization. libc provides the necessary interfaces via its RTLDINFO 171 * structure and/or later _ld_libc() calls. 172 * 173 * These external functions are maintained for each link-map list, and used 174 * where appropriate. The functions are associated with the object that 175 * provided them, so that should the object be deleted (say, from an alternative 176 * link-map), the functions can be removed. 177 */ 178 typedef struct { 179 Rt_map *lc_lmp; /* function provider */ 180 union { 181 int (*lc_func)(); /* external function pointer */ 182 uintptr_t lc_val; /* external value */ 183 char *lc_ptr; /* external character pointer */ 184 } lc_un; 185 } Lc_desc; 186 187 /* 188 * Link map list definition. Link-maps are used to describe each loaded object. 189 * Lists of these link-maps describe the various namespaces within a process. 190 * The process executable and its dependencies are maintained on the lml_main 191 * list. The runtime linker, and its dependencies are maintained on the 192 * lml_rtld list. Additional lists can be created (see dlmopen()) for such 193 * things as auditors and their dependencies. 194 * 195 * Each link-map list maintains an Alist of one, or more, linked lists of 196 * link-maps. For backward compatibility, the lm_head/lm_tail elements are 197 * initialized to the first linked-list of link-maps: 198 * 199 * Lm_list 200 * ---------- 201 * | lm_tail | ------------------------------------ 202 * | lm_head | -------------------- | 203 * | | | Rt_map | Rt_map 204 * | | | ------ | ------ 205 * | | Alist --> | | |--> | | 206 * | | --------- | | | -- | | 207 * | lm_lists | ----> | | | | | --> | | 208 * | | |---------| | | | | | | 209 * | | | lc_head | -- ------ | ------ 210 * | | | lc_tail | ------------------ 211 * | | |---------| 212 * ---------- | lc_head | 213 * | lc_tail | 214 * |---------| 215 * 216 * Multiple link-map lists exist to support the addition of lazy loaded 217 * families, filtee families, and dlopen() families. The intent of these 218 * lists is to insure that a family of objects that are to be loaded are 219 * fully relocatable, and hence usable, before they become part of the main 220 * (al_data[0]) link-map control list. This main link-map control list is 221 * the only list in existence when control is transferred to user code. 222 * 223 * During process initialization, the dynamic executable and its non-lazy 224 * dependencies are maintained on al_data[0]. If a new object is loaded, then 225 * this object is added to the next available control list [1], typically 226 * al_data[1]. Any dependencies of this object that have not already been 227 * loaded are added to the same control list. Once all of the objects on the 228 * new control list have been successfully relocated, the objects are moved from 229 * the new control list to the highest control list to which objects of the new 230 * control list bound to, typically al_data[1] to al_data[0]. 231 * 232 * Each loading scenario can be broken down as follows: 233 * 234 * setup() - only the initial link-map control list is used: 235 * i. create al_data[0] 236 * ii. add new link-map for main on al_data[0] 237 * iii. analyze al_data[0] to add all non-lazy dependencies 238 * iv. relocate al_data[0] dependencies. 239 * 240 * dlopen() - the initiator can only be the initial link-map control list: 241 * i. create al_data[1] from caller al_data[0] 242 * ii. add new link-map for the dlopen'ed object on al_data[1] 243 * iii. analyze al_data[1] to add all non-lazy dependencies 244 * iv. relocate al_data[1] dependencies, and move to al_data[0]. 245 * 246 * filtee and lazy loading processing - the initiator can be any link-map 247 * control list that is being relocated: 248 * i. create al_data[y] from caller al_data[x] 249 * ii. add new link-map for the new object on al_data[y] 250 * iii. analyze al_data[y] to add all non-lazy dependencies 251 * iv. relocate al_data[y] dependencies, and move to al_data[x]. 252 * 253 * This Alist therefore maintains a stack of link-map control lists. The newest 254 * link-map control list can locate symbols within any of the former lists, 255 * however, control is not passed to a former list until the newest lists 256 * processing is complete. Thus, objects can't bind to new objects until they 257 * have been fully analyzed and relocated. 258 * 259 * [1] Note, additional link-map control list creation occurs after the head 260 * link-map object (typically the dynamic executable) has been relocated. This 261 * staging is required to satisfy the binding requirements of copy relocations. 262 * Copy relocations, effectively, transfer the bindings of the copied data 263 * (say _iob in libc.so.1) to the copy location (_iob in the application). 264 * Thus an object that might bind to the original copy data must be redirected 265 * to the copy reference. As the knowledge of a copy relocation having taken 266 * place is only known after relocating the application, link-map control list 267 * additions are suspended until after this relocation has completed. 268 */ 269 typedef struct { 270 Rt_map *lc_head; 271 Rt_map *lc_tail; 272 APlist *lc_now; /* pending promoted bind-now objects */ 273 uint_t lc_flags; 274 } Lm_cntl; 275 276 #define LMC_FLG_ANALYZING 0x01 /* control list is being analyzed */ 277 #define LMC_FLG_RELOCATING 0x02 /* control list is being relocated */ 278 #define LMC_FLG_REANALYZE 0x04 /* repeat analysis (established when */ 279 /* interposers are added */ 280 281 struct lm_list { 282 /* 283 * BEGIN: Exposed to rtld_db - don't move, don't delete 284 */ 285 Rt_map *lm_head; /* linked list pointers to active */ 286 Rt_map *lm_tail; /* link-map list */ 287 APlist *lm_handle; /* not used by rtld_db - but spacing */ 288 /* is required for flags */ 289 Word lm_flags; 290 /* 291 * END: Exposed to rtld_db - don't move, don't delete 292 */ 293 Alist *lm_rti; /* list of RTLDINFO tables */ 294 Audit_list *lm_alp; /* audit list descriptor */ 295 avl_tree_t *lm_fpavl; /* avl tree of objects loaded */ 296 Alist *lm_lists; /* active and pending link-map lists */ 297 char ***lm_environ; /* pointer to environment array */ 298 Word lm_tflags; /* transferable flags */ 299 uint_t lm_obj; /* total number of objs on link-map */ 300 uint_t lm_init; /* new obj since last init processing */ 301 uint_t lm_lazy; /* number of objects with pending */ 302 /* lazy dependencies */ 303 uint_t lm_tls; /* new obj that require TLS */ 304 uint_t lm_lmid; /* unique link-map list identifier, */ 305 char *lm_lmidstr; /* and associated diagnostic string */ 306 Alist *lm_aud_cookies; /* local auditor cookies */ 307 Lc_desc lm_lcs[CI_MAX]; /* external libc functions */ 308 }; 309 310 #ifdef _SYSCALL32 311 struct lm_list32 { 312 /* 313 * BEGIN: Exposed to rtld_db - don't move, don't delete 314 */ 315 Elf32_Addr lm_head; 316 Elf32_Addr lm_tail; 317 Elf32_Addr lm_handle; 318 Elf32_Word lm_flags; 319 /* 320 * END: Exposed to rtld_db - don't move, don't delete 321 */ 322 Elf32_Addr lm_rti; 323 Elf32_Addr lm_fpavl; 324 Elf32_Addr lm_lists; 325 Elf32_Addr lm_environ; 326 Elf32_Word lm_tflags; 327 uint_t lm_obj; 328 uint_t lm_init; 329 uint_t lm_lazy; 330 uint_t lm_tls; 331 uint_t lm_lmid; 332 Elf32_Addr lm_lmidstr; 333 Elf32_Addr lm_aud_cookies; 334 Elf32_Addr lm_lcs[CI_MAX]; 335 }; 336 #endif /* _SYSCALL32 */ 337 338 /* 339 * Possible Link_map list flags (Lm_list.lm_flags) 340 */ 341 /* 342 * BEGIN: Exposed to rtld_db - don't move, don't delete 343 */ 344 #define LML_FLG_BASELM 0x00000001 /* primary link-map */ 345 #define LML_FLG_RTLDLM 0x00000002 /* rtld link-map */ 346 /* 347 * END: Exposed to rtld_db - don't move, don't delete 348 */ 349 #define LML_FLG_ACTAUDIT 0x00000004 /* audit activity posted */ 350 #define LML_FLG_PLTREL 0x00000008 /* deferred plt relocation */ 351 /* initialization (ld.so.1 */ 352 /* only) */ 353 #define LML_FLG_HOLDLOCK 0x00000010 /* hold the rtld mutex lock */ 354 #define LML_FLG_ENVIRON 0x00000020 /* environ var initialized */ 355 #define LML_FLG_INTRPOSE 0x00000040 /* interposing objs on list */ 356 #define LML_FLG_LOCAUDIT 0x00000080 /* local auditors exists for */ 357 /* this link-map list */ 358 #define LML_FLG_LOADAVAIL 0x00000100 /* load anything available */ 359 #define LML_FLG_IGNRELERR 0x00000200 /* ignore relocation errors - */ 360 /* internal for crle(1) */ 361 #define LML_FLG_STARTREL 0x00000400 /* relocation started */ 362 #define LML_FLG_ATEXIT 0x00000800 /* atexit processing */ 363 #define LML_FLG_OBJADDED 0x00001000 /* object(s) added */ 364 #define LML_FLG_OBJDELETED 0x00002000 /* object(s) deleted */ 365 #define LML_FLG_OBJREEVAL 0x00004000 /* existing object(s) needs */ 366 /* tsort reevaluation */ 367 #define LML_FLG_INTRPOSETSORT 0x00008000 /* interpose tsorting done */ 368 #define LML_FLG_AUDITNOTIFY 0x00010000 /* audit consistent required */ 369 #define LML_FLG_GROUPSEXIST 0x00020000 /* local groups exist */ 370 371 #define LML_FLG_TRC_LDDSTUB 0x00100000 /* identify lddstub */ 372 #define LML_FLG_TRC_ENABLE 0x00200000 /* tracing enabled (ldd) */ 373 #define LML_FLG_TRC_WARN 0x00400000 /* print warnings for undefs */ 374 #define LML_FLG_TRC_VERBOSE 0x00800000 /* verbose (versioning) trace */ 375 #define LML_FLG_TRC_SEARCH 0x01000000 /* trace search paths */ 376 #define LML_FLG_TRC_UNREF 0x02000000 /* trace unreferenced */ 377 /* dependencies */ 378 #define LML_FLG_TRC_UNUSED 0x04000000 /* trace unused dependencies */ 379 #define LML_FLG_TRC_INIT 0x08000000 /* print .init order */ 380 #define LML_FLG_TRC_NOUNRESWEAK 0x10000000 /* unresolved weak references */ 381 /* are not allowed */ 382 #define LML_FLG_TRC_NOPAREXT 0x20000000 /* unresolved PARENT/EXTERN */ 383 /* references are not */ 384 /* allowed */ 385 #define LML_MSK_TRC 0xfff00000 /* tracing mask */ 386 387 /* 388 * Possible Link_map transferable flags (Lm_list.lm_tflags), i.e., link-map 389 * list flags that can be propagated to any new link-map list created. 390 */ 391 #define LML_TFLG_NOLAZYLD 0x00000001 /* lazy loading disabled */ 392 #define LML_TFLG_NODIRECT 0x00000002 /* direct bindings disabled */ 393 #define LML_TFLG_NOAUDIT 0x00000004 /* auditing disabled */ 394 #define LML_TFLG_LOADFLTR 0x00000008 /* trigger filtee loading */ 395 396 #define LML_TFLG_AUD_PREINIT 0x00001000 /* preinit (audit) exists */ 397 #define LML_TFLG_AUD_OBJSEARCH 0x00002000 /* objsearch (audit) exists */ 398 #define LML_TFLG_AUD_OBJOPEN 0x00004000 /* objopen (audit) exists */ 399 #define LML_TFLG_AUD_OBJFILTER 0x00008000 /* objfilter (audit) exists */ 400 #define LML_TFLG_AUD_OBJCLOSE 0x00010000 /* objclose (audit) exists */ 401 #define LML_TFLG_AUD_SYMBIND 0x00020000 /* symbind (audit) exists */ 402 #define LML_TFLG_AUD_PLTENTER 0x00040000 /* pltenter (audit) exists */ 403 #define LML_TFLG_AUD_PLTEXIT 0x00080000 /* pltexit (audit) exists */ 404 #define LML_TFLG_AUD_ACTIVITY 0x00100000 /* activity (audit) exists */ 405 406 /* 407 * NOTE: Each auditing module establishes a set of audit flags, AFLAGS(), that 408 * define the auditing interfaces the module offers. These auditing flags are 409 * the LML_TFLG_AUD_ flags defined above. Global auditors result in setting 410 * the lm_tflags too. Local auditors only use the AFLAGS(). All tests for 411 * auditing inspect the lm_tflags and AFLAGS() for a specific auditing 412 * interface, and thus use the same flag to test for both types of auditors. 413 */ 414 #define LML_TFLG_AUD_MASK 0x0ffff000 /* audit interfaces mask */ 415 416 /* 417 * Define a Group Handle. 418 * 419 * The capability of ld.so.1 to associate a group of objects, look for symbols 420 * within that group, ensure that groups are isolated from one another (with 421 * regard to relocations), and to unload a group, centers around a handle. 422 * 423 * Dependencies can be added to an existing handle as the dependencies are 424 * lazily loaded. The core dependencies on the handle are the ldd(1) list of 425 * the referenced object. 426 * 427 * Handles can be created from: 428 * 429 * - a dlopen() request. This associates a caller to a reference object, 430 * and the referenced objects dependencies. This group of objects can 431 * then be inspected for symbols (dlsym()). 432 * - a filtering request. This associates a filter (caller) to a referenced 433 * object (filtee). The redirection of filter symbols to their filtee 434 * counterpart is essentially a dlsym() using the filtee's handle. 435 * 436 * The handle created for these events is referred to as a public handle. This 437 * handle tracks the referenced object, all of the dependencies of the 438 * referenced object, and the caller (parent). 439 * 440 * Presently, an object may have two handles, one requested with RTLD_FIRST 441 * and one without. 442 * 443 * A handle may be referenced by any number of callers (parents). A reference 444 * count tracks the number. A dlclose() operation drops the reference count, 445 * and when the count is zero, the handle is used to determine the family of 446 * objects to unload. As bindings may occur to objects on the handle from 447 * other handles, it may not be possible to remove a complete family of objects 448 * or the handle itself. Handles in this state are moved to an orphan list. 449 * A handle on the orphan list is taken off the orphan list if the associated 450 * object is reopened. Otherwise, the handle remains on the orphan list for 451 * the duration of the process. The orphan list is inspected any time objects 452 * are unloaded, to determine if the orphaned objects can also be unloaded. 453 * 454 * Handles can also be created for internal uses: 455 * 456 * - to promote objects to RTLD_NOW. 457 * - to establish families for symbol binding fallback, required when lazy 458 * loadable objects are still pending. 459 * 460 * The handle created for these events is referred to as a private handle. This 461 * handle does not need to track the caller (parent), and because of this, does 462 * not need to be considered during dlclose() operations, as the handle can not 463 * be referenced by callers outside of the referenced objects family. 464 * 465 * Note, a private handle is essentially a subset of a public handle. Should 466 * an internal operation require a private handle, and a public handle already 467 * exist, the public handle can be used. Should an external operation require 468 * a public handle, and a private handle exist, the private handle is promoted 469 * to a public handle. Any handle that gets created will remain in existence 470 * for the life time of the referenced object. 471 * 472 * Objects can be dlopened using RTLD_NOW. This attribute requires that all 473 * relocations of the object, and its dependencies are processed immediately, 474 * before return to the caller. Typically, an object is loaded without 475 * RTLD_NOW, and procedure linkage relocations are satisfied when their 476 * associated function is first called. If an object is already loaded, and an 477 * RTLD_NOW request is made, then the object, and its dependencies, most undergo 478 * additional relocation processing. This promotion from lazy binding to 479 * immediate binding is carried out using handles, as the handle defines the 480 * dependencies that must be processed. 481 * 482 * To ensure that objects within a lazy loadable environment can be relocated, 483 * no matter whether the objects have their dependencies described completely, 484 * a symbol lookup fallback is employed. Any pending lazy loadable objects are 485 * loaded, and a handle established to search the object and it's dependencies 486 * for the required symbol. 487 * 488 * A group handle (and its associated group descriptors), is referenced from 489 * a link-map's HANDLES and GROUPS lists. Note, Aplist's are diagramed to 490 * fully expose the allocations required to establish the data structure 491 * relationships. 492 * 493 * Grp_desc 494 * Alist 495 * ----------- 496 * --> | | 497 * | |-----------| 498 * | | gd_depend | --------- 499 * | | | | 500 * | |-----------| | 501 * --------|--- | gd_depend | | 502 * | | | (parent) | | 503 * | | |-----------| | 504 * | | | gd_depend | | 505 * | | | | | 506 * | | | | | 507 * | | ----------- | 508 * | | | 509 * | | Grp_hdl | 510 * | | ----------- | 511 * | -- | gh_depends | | 512 * | --------- | gh_ownlmp | | 513 * | | | | | 514 * | | | | | 515 * | | | | | 516 * Rt_map | | ------------ | Rt_map 517 * ---------- | | ^ ^ | ---------- 518 * | | <- | | | --> | | 519 * | | <--- -------- | | | | 520 * | HANDLES | ----> | | | | -------- | | 521 * | | | | | | | | <---- | GROUPS | 522 * | | | | --- | | | | | 523 * | | | | --- | | | | 524 * | | -------- | | | | 525 * ---------- Aplist -------- ---------- 526 * Aplist 527 */ 528 typedef struct { 529 Alist *gh_depends; /* handle dependency list */ 530 Rt_map *gh_ownlmp; /* handle owners link-map */ 531 Lm_list *gh_ownlml; /* handle owners link-map list */ 532 uint_t gh_refcnt; /* handle reference count */ 533 uint_t gh_flags; /* handle flags (GPH_ values) */ 534 } Grp_hdl; 535 536 /* 537 * Define the two categories of handle. 538 */ 539 #define GPH_PUBLIC 0x0001 /* handle returned to caller(s) */ 540 #define GPH_PRIVATE 0x0002 /* handle used internally */ 541 542 /* 543 * Define any flags that affects how the handle is used. 544 */ 545 #define GPH_ZERO 0x0010 /* special handle for dlopen(0) */ 546 #define GPH_LDSO 0x0020 /* special handle for ld.so.1 */ 547 #define GPH_FIRST 0x0040 /* dlsym() can only use originating */ 548 /* dependency */ 549 #define GPH_FILTEE 0x0080 /* handle identifies a filtee, used */ 550 /* for diagnostics only */ 551 /* 552 * Define any state that is associated with the handle. 553 */ 554 #define GPH_INITIAL 0x0100 /* handle is initialized */ 555 556 /* 557 * Define a Group Descriptor. 558 * 559 * Each dependency associated with a group handle is maintained by a group 560 * descriptor. The descriptor defines the associated dependency together with 561 * flags that indicate how the dependency can be used. 562 */ 563 typedef struct { 564 Rt_map *gd_depend; /* dependency */ 565 uint_t gd_flags; /* dependency flags (GPD_ values) */ 566 } Grp_desc; 567 568 #define GPD_DLSYM 0x0001 /* dependency available to dlsym() */ 569 #define GPD_RELOC 0x0002 /* dependency available to satisfy */ 570 /* relocation binding */ 571 #define GPD_ADDEPS 0x0004 /* dependencies of this dependency */ 572 /* should be added to handle */ 573 #define GPD_PARENT 0x0008 /* dependency is a parent */ 574 #define GPD_FILTER 0x0010 /* dependency is our filter */ 575 #define GPD_REMOVE 0x0100 /* descriptor is a candidate for */ 576 /* removal from the group */ 577 578 /* 579 * Define threading structures. For compatibility with libthread (T1_VERSION 1 580 * and TI_VERSION 2) our locking structure is sufficient to hold a mutex or a 581 * readers/writers lock. 582 */ 583 typedef struct { 584 union { 585 mutex_t l_mutex; 586 rwlock_t l_rwlock; 587 } u; 588 } Rt_lock; 589 590 typedef cond_t Rt_cond; 591 592 /* 593 * Define a dynamic section information descriptor. This parallels the entries 594 * in the .dynamic section and holds auxiliary information to implement lazy 595 * loading and filtee processing. 596 */ 597 typedef struct { 598 uint_t di_flags; 599 void *di_info; 600 const char *di_name; 601 } Dyninfo; 602 603 #define FLG_DI_STDFLTR 0x00001 /* .dynamic entry for DT_FILTER */ 604 #define FLG_DI_AUXFLTR 0x00002 /* .dynamic entry for DT_AUXILIARY */ 605 #define FLG_DI_SYMFLTR 0x00004 /* .dynamic entry for DT_SYMFILTER */ 606 /* and DT_SYMAUXILIARY */ 607 #define MSK_DI_FILTER 0x0000f /* mask for all filter possibilities */ 608 609 #define FLG_DI_POSFLAG1 0x00010 /* .dynamic entry for DT_POSFLAG_1 */ 610 #define FLG_DI_NEEDED 0x00020 /* .dynamic entry for DT_NEEDED */ 611 #define FLG_DI_REGISTER 0x00040 /* .dynamic entry for DT_REGISTER */ 612 #define FLG_DI_IGNORE 0x00080 /* .dynamic entry should be ignored */ 613 614 #define FLG_DI_LAZY 0x00100 /* lazy needed entry, preceded by */ 615 /* DF_P1_LAZYLOAD (DT_POSFLAG_1) */ 616 #define FLG_DI_GROUP 0x00200 /* group needed entry, preceded by */ 617 /* DF_P1_GROUPPERM (DT_POSFLAG_1) */ 618 #define FLG_DI_DEFERRED 0x00400 /* deferred needed entry, preceded by */ 619 /* DF_P1_DEFERRED (DT_POSFLAG_1) */ 620 621 #define FLG_DI_LAZYFAIL 0x01000 /* the lazy loading of this entry */ 622 /* failed */ 623 #define FLG_DI_LDD_DONE 0x02000 /* entry has been processed (ldd) */ 624 #define FLG_DI_DEF_DONE 0x04000 /* entry has been processed (dlinfo) */ 625 626 /* 627 * Data structure to track AVL tree of pathnames. This structure provides the 628 * basis of both the "not-found" node tree, and the "full-path" node tree. Both 629 * of these trees persist for the life of a process, although the "not-found" 630 * tree may be moved aside during a dlopen() or dlsym() fall back operation. 631 */ 632 typedef struct { 633 const char *pn_name; /* path name */ 634 avl_node_t pn_avl; /* avl book-keeping (see SGSOFFSETOF) */ 635 uint_t pn_hash; /* path name hash value */ 636 } PathNode; 637 638 /* 639 * Data structure to track AVL tree for full path names of objects that are 640 * loaded into memory. 641 */ 642 typedef struct { 643 PathNode fpn_node; /* path node */ 644 Rt_map *fpn_lmp; /* object link-map */ 645 } FullPathNode; 646 647 /* 648 * A given link-map can hold either a supplier or receiver copy 649 * relocation list, but not both. This union is used to overlap 650 * the space used for the two lists. 651 */ 652 typedef union { 653 Alist *rtc_r; /* receiver list (Rel_copy) */ 654 APlist *rtc_s; /* supplier list (Rt_map *) */ 655 } Rt_map_copy; 656 657 658 /* 659 * Link-map definition. 660 */ 661 struct rt_map { 662 /* 663 * BEGIN: Exposed to rtld_db - don't move, don't delete 664 */ 665 Link_map rt_public; /* public data */ 666 const char *rt_pathname; /* full pathname of loaded object */ 667 ulong_t rt_padstart; /* start of image (including padding) */ 668 ulong_t rt_padimlen; /* size of image (including padding */ 669 ulong_t rt_msize; /* total memory reservation range */ 670 uint_t rt_flags; /* state flags, see FLG below */ 671 uint_t rt_flags1; /* state flags1, see FL1 below */ 672 ulong_t rt_tlsmodid; /* TLS module id */ 673 /* 674 * END: Exposed to rtld_db - don't move, don't delete 675 */ 676 APlist *rt_alias; /* list of linked file names */ 677 APlist *rt_fpnode; /* list of FullPathNode AVL nodes */ 678 char *rt_runpath; /* LD_RUN_PATH and its equivalent */ 679 Alist *rt_runlist; /* Pdesc structures */ 680 APlist *rt_depends; /* list of dependencies */ 681 APlist *rt_callers; /* list of callers */ 682 APlist *rt_handles; /* dlopen handles */ 683 APlist *rt_groups; /* groups we're a member of */ 684 struct fct *rt_fct; /* file class table for this object */ 685 void *rt_priv; /* private data, object type specific */ 686 Lm_list *rt_list; /* link map list we belong to */ 687 uint_t rt_objfltrndx; /* object filtees .dynamic index */ 688 uint_t rt_symsfltrcnt; /* number of standard symbol filtees */ 689 uint_t rt_symafltrcnt; /* number of auxiliary symbol filtees */ 690 int rt_mode; /* usage mode, see RTLD mode flags */ 691 int rt_sortval; /* temporary buffer to traverse graph */ 692 uint_t rt_cycgroup; /* cyclic group */ 693 dev_t rt_stdev; /* device id and inode number for .so */ 694 rtld_ino_t rt_stino; /* multiple inclusion checks */ 695 const char *rt_origname; /* original pathname of loaded object */ 696 size_t rt_dirsz; /* and its size */ 697 size_t rt_lmsize; /* size of the link-map allocation */ 698 Rt_map_copy rt_copy; /* list of copy relocations */ 699 Audit_desc *rt_auditors; /* audit descriptor array */ 700 Audit_info *rt_audinfo; /* audit information descriptor */ 701 Syminfo *rt_syminfo; /* elf .syminfo section - here */ 702 /* because it is checked in */ 703 /* common code */ 704 Addr *rt_initarray; /* .init_array table */ 705 Addr *rt_finiarray; /* .fini_array table */ 706 Addr *rt_preinitarray; /* .preinit_array table */ 707 mmapobj_result_t *rt_mmaps; /* array of mapping information */ 708 uint_t rt_mmapcnt; /* and associated number */ 709 uint_t rt_initarraysz; /* size of .init_array table */ 710 uint_t rt_finiarraysz; /* size of .fini_array table */ 711 uint_t rt_preinitarraysz; /* size of .preinit_array table */ 712 Dyninfo *rt_dyninfo; /* .dynamic information descriptors */ 713 uint_t rt_dyninfocnt; /* count of dyninfo entries */ 714 uint_t rt_relacount; /* no. of RELATIVE relocations */ 715 uint_t rt_idx; /* hold index within linkmap list */ 716 uint_t rt_lazy; /* number of lazy dependencies */ 717 /* pending */ 718 Cap *rt_cap; /* capabilities data */ 719 Capchain *rt_capchain; /* capabilities chain data */ 720 uint_t rt_cntl; /* link-map control list we belong to */ 721 uint_t rt_aflags; /* auditor flags, see LML_TFLG_AUD_ */ 722 /* address of _init */ 723 void (*rt_init)(void); 724 /* address of _fini */ 725 void (*rt_fini)(void); 726 /* link map symbol interpreter */ 727 int (*rt_symintp)(Slookup *, Sresult *, uint_t *, int *); 728 }; 729 730 #ifdef _SYSCALL32 731 /* 732 * Structure to allow 64-bit rtld_db to read 32-bit processes out of procfs. 733 */ 734 typedef union { 735 uint32_t rtc_r; 736 uint32_t rtc_s; 737 } Rt_map_copy32; 738 739 typedef struct rt_map32 { 740 /* 741 * BEGIN: Exposed to rtld_db - don't move, don't delete 742 */ 743 Link_map32 rt_public; 744 uint32_t rt_pathname; 745 uint32_t rt_padstart; 746 uint32_t rt_padimlen; 747 uint32_t rt_msize; 748 uint32_t rt_flags; 749 uint32_t rt_flags1; 750 uint32_t rt_tlsmodid; 751 /* 752 * END: Exposed to rtld_db - don't move, don't delete 753 */ 754 uint32_t rt_alias; 755 uint32_t rt_fpnode; 756 uint32_t rt_runpath; 757 uint32_t rt_runlist; 758 uint32_t rt_depends; 759 uint32_t rt_callers; 760 uint32_t rt_handles; 761 uint32_t rt_groups; 762 uint32_t rt_fct; 763 uint32_t rt_priv; 764 uint32_t rt_list; 765 uint32_t rt_objfltrndx; 766 uint32_t rt_symsfltrcnt; 767 uint32_t rt_symafltrcnt; 768 int32_t rt_mode; 769 int32_t rt_sortval; 770 uint32_t rt_cycgroup; 771 uint32_t rt_stdev; 772 uint32_t rt_stino; 773 uint32_t rt_origname; 774 uint32_t rt_dirsz; 775 Rt_map_copy32 rt_copy; 776 uint32_t rt_auditors; 777 uint32_t rt_audinfo; 778 uint32_t rt_syminfo; 779 uint32_t rt_initarray; 780 uint32_t rt_finiarray; 781 uint32_t rt_preinitarray; 782 uint32_t rt_mmaps; 783 uint32_t rt_mmapcnt; 784 uint32_t rt_initarraysz; 785 uint32_t rt_finiarraysz; 786 uint32_t rt_preinitarraysz; 787 uint32_t rt_dyninfo; 788 uint32_t rt_dyninfocnt; 789 uint32_t rt_relacount; 790 uint32_t rt_idx; 791 uint32_t rt_lazy; 792 uint32_t rt_cap; 793 uint32_t rt_capchain; 794 uint32_t rt_cntl; 795 uint32_t rt_aflags; 796 uint32_t rt_init; 797 uint32_t rt_fini; 798 uint32_t rt_symintp; 799 } Rt_map32; 800 801 #endif /* _SYSCALL32 */ 802 803 /* 804 * Link map state flags. 805 */ 806 /* 807 * BEGIN: Exposed to rtld_db - don't move, don't delete 808 */ 809 #define FLG_RT_ISMAIN 0x00000001 /* object represents main executable */ 810 #define FLG_RT_IMGALLOC 0x00000002 /* image is allocated (not mmap'ed) */ 811 /* 812 * Available for r_debug version >= R_RTLDDB_VERSION5 813 */ 814 #define FLG_RT_RELOCED 0x00000004 /* object has been relocated */ 815 /* 816 * END: Exposed to rtld_db - don't move, don't delete 817 */ 818 #define FLG_RT_SETGROUP 0x00000008 /* group establishment required */ 819 #define FLG_RT_CAP 0x00000010 /* process $CAPABILITY expansion */ 820 #define FLG_RT_OBJECT 0x00000020 /* object processing (ie. .o's) */ 821 #define FLG_RT_NEWLOAD 0x00000040 /* object is newly loaded */ 822 #define FLG_RT_NODUMP 0x00000080 /* object can't be dldump(3x)'ed */ 823 #define FLG_RT_DELETE 0x00000100 /* object can be deleted */ 824 #define FLG_RT_ANALYZED 0x00000200 /* object has been analyzed */ 825 #define FLG_RT_INITDONE 0x00000400 /* objects .init has been completed */ 826 #define FLG_RT_TRANS 0x00000800 /* object is acting as a translator */ 827 #define FLG_RT_FIXED 0x00001000 /* image location is fixed */ 828 #define FLG_RT_PRELOAD 0x00002000 /* object was preloaded */ 829 #define FLG_RT_ALTER 0x00004000 /* alternative object used */ 830 #define FLG_RT_LOADFLTR 0x00008000 /* trigger filtee loading */ 831 #define FLG_RT_AUDIT 0x00010000 /* object is an auditor */ 832 #define FLG_RT_MODESET 0x00020000 /* MODE() has been initialized */ 833 #define FLG_RT_ANALZING 0x00040000 /* object is being analyzed */ 834 #define FLG_RT_INITFRST 0x00080000 /* execute .init first */ 835 #define FLG_RT_NOOPEN 0x00100000 /* dlopen() not allowed */ 836 #define FLG_RT_FINICLCT 0x00200000 /* fini has been collected (tsort) */ 837 #define FLG_RT_INITCALL 0x00400000 /* objects .init has been called */ 838 #define FLG_RT_OBJINTPO 0x00800000 /* object is a global interposer */ 839 #define FLG_RT_SYMINTPO 0x01000000 /* object contains symbol interposer */ 840 #define MSK_RT_INTPOSE 0x01800000 /* mask for all interposer */ 841 /* possibilities */ 842 #define FLG_RT_MOVE 0x02000000 /* object needs move operation */ 843 #define FLG_RT_RELOCING 0x04000000 /* object is being relocated */ 844 #define FLG_RT_REGSYMS 0x08000000 /* object has DT_REGISTER entries */ 845 #define FLG_RT_INITCLCT 0x10000000 /* init has been collected (tsort) */ 846 #define FLG_RT_PUBHDL 0x20000000 /* generate a handle for this object */ 847 #define FLG_RT_PRIHDL 0x40000000 /* either public or private */ 848 849 #define FL1_RT_COPYTOOK 0x00000001 /* copy relocation taken */ 850 #define FL1_RT_ALTCHECK 0x00000002 /* alternative system capabilities */ 851 /* checked */ 852 #define FL1_RT_ALTCAP 0x00000004 /* alternative system capabilities */ 853 /* should be used */ 854 #define FL1_RT_CONFSET 0x00000008 /* object was loaded by crle(1) */ 855 #define FL1_RT_NODEFLIB 0x00000010 /* ignore default library search */ 856 #define FL1_RT_ENDFILTE 0x00000020 /* filtee terminates filters search */ 857 #define FL1_RT_DISPREL 0x00000040 /* object has *disp* relocation */ 858 #define FL1_RT_DTFLAGS 0x00000080 /* DT_FLAGS element exists */ 859 #define FL1_RT_LDDSTUB 0x00000100 /* identify lddstub */ 860 #define FL1_RT_NOINIFIN 0x00000200 /* no .init or .fini exists */ 861 #define FL1_RT_USED 0x00000400 /* symbol referenced from this object */ 862 #define FL1_RT_SYMBOLIC 0x00000800 /* DF_SYMBOLIC was set - use */ 863 /* symbolic sym resolution */ 864 #define FL1_RT_OBJSFLTR 0x00001000 /* object is acting as a standard */ 865 #define FL1_RT_OBJAFLTR 0x00002000 /* or auxiliary filter */ 866 #define FL1_RT_SYMSFLTR 0x00004000 /* symbol is acting as a standard */ 867 #define FL1_RT_SYMAFLTR 0x00008000 /* or auxiliary filter */ 868 #define MSK_RT_FILTER 0x0000f000 /* mask for all filter possibilities */ 869 870 #define FL1_RT_TLSADD 0x00010000 /* objects TLS has been registered */ 871 #define FL1_RT_TLSSTAT 0x00020000 /* object requires static TLS */ 872 #define FL1_RT_DIRECT 0x00040000 /* object has DIRECT bindings enabled */ 873 #define FL1_RT_GLOBAUD 0x00080000 /* establish global auditing */ 874 #define FL1_RT_DEPAUD 0x00100000 /* audit library from DT_DEPAUDIT */ 875 876 /* 877 * Flags for the tls_modactivity() routine 878 */ 879 #define TM_FLG_MODADD 0x01 /* call tls_modadd() interface */ 880 #define TM_FLG_MODREM 0x02 /* call tls_modrem() interface */ 881 882 /* 883 * Macros for getting to exposed, link_map data (R_RTLDDB_VERSION <= 2). 884 */ 885 #define ADDR(X) ((X)->rt_public.l_addr) 886 #define NAME(X) ((X)->rt_public.l_name) 887 #define DYN(X) ((X)->rt_public.l_ld) 888 #define NEXT(X) ((X)->rt_public.l_next) 889 #define PREV(X) ((X)->rt_public.l_prev) 890 #define REFNAME(X) ((X)->rt_public.l_refname) 891 892 /* 893 * An Rt_map starts with a Link_map, followed by other information. 894 * ld.so.1 allocates Rt_map structures, and then casts them to Link_map, 895 * and back, depending on context. 896 * 897 * On some platforms, Rt_map can have a higher alignment requirement 898 * than Link_map. On such platforms, the cast from Link_map to Rt_map will 899 * draw an E_BAD_PTR_CAST_ALIGN warning from lint. Since we allocate 900 * the memory as the higher alignment Rt_map, we know that this is a safe 901 * conversion. The LINKMAP_TO_RTMAP macro is used to handle the conversion 902 * in a manner that satisfies lint. 903 */ 904 #ifdef lint 905 #define LINKMAP_TO_RTMAP(X) (Rt_map *)(void *)(X) 906 #else 907 #define LINKMAP_TO_RTMAP(X) (Rt_map *)(X) 908 #endif 909 910 /* 911 * Convenience macros for the common case of using 912 * NEXT()/PREV() and casting the result to (Rt_map *) 913 */ 914 #define NEXT_RT_MAP(X) LINKMAP_TO_RTMAP(NEXT(X)) 915 #define PREV_RT_MAP(X) LINKMAP_TO_RTMAP(PREV(X)) 916 917 /* 918 * Macros for getting to exposed, link_map data (R_RTLDDB_VERSION3). 919 */ 920 #define PATHNAME(X) ((X)->rt_pathname) 921 #define PADSTART(X) ((X)->rt_padstart) 922 #define PADIMLEN(X) ((X)->rt_padimlen) 923 #define MSIZE(X) ((X)->rt_msize) 924 #define FLAGS(X) ((X)->rt_flags) 925 #define FLAGS1(X) ((X)->rt_flags1) 926 927 /* 928 * Macros for getting to exposed, link_map data (R_RTLDDB_VERSION4). 929 */ 930 #define TLSMODID(X) ((X)->rt_tlsmodid) 931 932 /* 933 * Macros for getting to unexposed, link-map data. 934 */ 935 #define LMSIZE(X) ((X)->rt_lmsize) 936 #define AFLAGS(X) ((X)->rt_aflags) 937 #define ALIAS(X) ((X)->rt_alias) 938 #define FPNODE(X) ((X)->rt_fpnode) 939 #define INIT(X) ((X)->rt_init) 940 #define FINI(X) ((X)->rt_fini) 941 #define RPATH(X) ((X)->rt_runpath) 942 #define RLIST(X) ((X)->rt_runlist) 943 #define DEPENDS(X) ((X)->rt_depends) 944 #define CALLERS(X) ((X)->rt_callers) 945 #define HANDLES(X) ((X)->rt_handles) 946 #define GROUPS(X) ((X)->rt_groups) 947 #define FCT(X) ((X)->rt_fct) 948 #define SYMINTP(X) ((X)->rt_symintp) 949 #define LIST(X) ((X)->rt_list) 950 #define OBJFLTRNDX(X) ((X)->rt_objfltrndx) 951 #define SYMSFLTRCNT(X) ((X)->rt_symsfltrcnt) 952 #define SYMAFLTRCNT(X) ((X)->rt_symafltrcnt) 953 #define MODE(X) ((X)->rt_mode) 954 #define SORTVAL(X) ((X)->rt_sortval) 955 #define CYCGROUP(X) ((X)->rt_cycgroup) 956 #define STDEV(X) ((X)->rt_stdev) 957 #define STINO(X) ((X)->rt_stino) 958 #define ORIGNAME(X) ((X)->rt_origname) 959 #define DIRSZ(X) ((X)->rt_dirsz) 960 #define COPY_R(X) ((X)->rt_copy.rtc_r) 961 #define COPY_S(X) ((X)->rt_copy.rtc_s) 962 #define AUDITORS(X) ((X)->rt_auditors) 963 #define AUDINFO(X) ((X)->rt_audinfo) 964 #define SYMINFO(X) ((X)->rt_syminfo) 965 #define INITARRAY(X) ((X)->rt_initarray) 966 #define FINIARRAY(X) ((X)->rt_finiarray) 967 #define PREINITARRAY(X) ((X)->rt_preinitarray) 968 #define MMAPS(X) ((X)->rt_mmaps) 969 #define MMAPCNT(X) ((X)->rt_mmapcnt) 970 #define INITARRAYSZ(X) ((X)->rt_initarraysz) 971 #define FINIARRAYSZ(X) ((X)->rt_finiarraysz) 972 #define PREINITARRAYSZ(X) ((X)->rt_preinitarraysz) 973 #define DYNINFO(X) ((X)->rt_dyninfo) 974 #define DYNINFOCNT(X) ((X)->rt_dyninfocnt) 975 #define RELACOUNT(X) ((X)->rt_relacount) 976 #define IDX(X) ((X)->rt_idx) 977 #define LAZY(X) ((X)->rt_lazy) 978 #define CNTL(X) ((X)->rt_cntl) 979 #define CAP(X) ((X)->rt_cap) 980 #define CAPCHAIN(X) ((X)->rt_capchain) 981 982 /* 983 * Flags for tsorting. 984 */ 985 #define RT_SORT_FWD 0x01 /* topological sort (.fini) */ 986 #define RT_SORT_REV 0x02 /* reverse topological sort (.init) */ 987 #define RT_SORT_DELETE 0x10 /* process FLG_RT_DELETE objects */ 988 /* only (called via dlclose()) */ 989 #define RT_SORT_INTPOSE 0x20 /* process interposer objects */ 990 991 /* 992 * Flags for lookup_sym (and hence find_sym) routines. 993 */ 994 #define LKUP_DEFT 0x0000 /* simple lookup request */ 995 #define LKUP_SPEC 0x0001 /* special ELF lookup (allows address */ 996 /* resolutions to plt[] entries) */ 997 #define LKUP_LDOT 0x0002 /* indicates the original A_OUT */ 998 /* symbol had a leading `.' */ 999 #define LKUP_FIRST 0x0004 /* lookup symbol in first link map */ 1000 /* only */ 1001 #define LKUP_COPY 0x0008 /* lookup symbol for a COPY reloc, do */ 1002 /* not bind to symbol at head */ 1003 #define LKUP_STDRELOC 0x0010 /* lookup originates from a standard */ 1004 /* relocation (elf_reloc()) */ 1005 #define LKUP_SELF 0x0020 /* lookup symbol in ourself - undef */ 1006 /* is valid */ 1007 #define LKUP_WEAK 0x0040 /* relocation reference is weak */ 1008 #define LKUP_NEXT 0x0080 /* request originates from RTLD_NEXT */ 1009 #define LKUP_NODESCENT 0x0100 /* don't descend through dependencies */ 1010 #define LKUP_NOFALLBACK 0x0200 /* don't fall back to loading */ 1011 /* pending lazy dependencies */ 1012 #define LKUP_DIRECT 0x0400 /* direct binding request */ 1013 #define LKUP_SYMNDX 0x0800 /* establish symbol index */ 1014 #define LKUP_SINGLETON 0x1000 /* search for a singleton symbol */ 1015 #define LKUP_STANDARD 0x2000 /* standard lookup - originated from */ 1016 /* head link-map element */ 1017 #define LKUP_WORLD 0x4000 /* ensure world lookup */ 1018 #define LKUP_DLSYM 0x8000 /* lookup stems from dlsym() request */ 1019 1020 /* 1021 * For the runtime linker to perform a symbol search, a number of data items 1022 * related to the search are required. An Slookup data structure is used to 1023 * convey this data to lookup_sym(), and in special cases, to other core 1024 * routines that provide the implementation details for lookup_sym() 1025 * 1026 * The symbol name (sl_name), the caller (sl_cmap), and the link-map from which 1027 * to start the search (sl_imap) are fundamental to the symbol search. The 1028 * initial search link-map might get modified by the core routines that provide 1029 * the implementation details for lookup_sym(). This modification accommodates 1030 * requirements such as processing a handle, direct binding and interposition. 1031 * The association between the caller and the potential destination also 1032 * determines whether the destination is a candidate to search. 1033 * 1034 * The lookup identifier (sl_id) is used to identify a runtime linker operation. 1035 * Within this operation, any lazy loads that fail are not re-examined. This 1036 * technique keeps the overhead of processing a failed lazy load to a minimum. 1037 * 1038 * Symbol searches that originate from a relocation record are accompanied by 1039 * the relocation index (sl_rsymndx), the symbol reference (sl_rsym) and 1040 * possibly the relocation type (sl_rtype). This data provides for determining 1041 * lazy loading, direct binding, and special symbol processing requirements 1042 * such as copy relocations and singleton lookup. 1043 * 1044 * The symbols hash value is computed by lookup_sym, and propagated throughout 1045 * the search engine. Note, occasionally the Slookup data is passed to a core 1046 * routine that provides the implementation details for lookup_sym(), ie. 1047 * elf_find_sym(), in which case the caller must initialize the hash value. 1048 * 1049 * The symbols binding information is established by lookup_sym() when the 1050 * symbols relocation type is supplied. Weak bindings allow relocations to 1051 * be set to zero should a symbol lookup fail. 1052 * 1053 * The flags allow the caller to control aspects of the search, including the 1054 * interpretation of copy relocations, etc. Note, a number of flag settings 1055 * are established in lookup_sym() from attributes of the symbol reference. 1056 */ 1057 struct slookup { 1058 const char *sl_name; /* symbol name */ 1059 Rt_map *sl_cmap; /* callers link-map */ 1060 Rt_map *sl_imap; /* initial link-map to search */ 1061 ulong_t sl_id; /* identifier for this lookup */ 1062 ulong_t sl_hash; /* symbol hash value */ 1063 ulong_t sl_rsymndx; /* referencing reloc symndx */ 1064 Sym *sl_rsym; /* referencing symbol */ 1065 uchar_t sl_rtype; /* relocation type associate with */ 1066 /* symbol */ 1067 uchar_t sl_bind; /* symbols binding (returned) */ 1068 uint_t sl_flags; /* lookup flags */ 1069 }; 1070 1071 #define SLOOKUP_INIT(sl, name, cmap, imap, id, hash, rsymndx, rsym, rtype, \ 1072 flags) \ 1073 (void) (sl.sl_name = (name), sl.sl_cmap = (cmap), sl.sl_imap = (imap), \ 1074 sl.sl_id = (id), sl.sl_hash = (hash), sl.sl_rsymndx = (rsymndx), \ 1075 sl.sl_rsym = (rsym), sl.sl_rtype = (rtype), sl.sl_bind = 0, \ 1076 sl.sl_flags = (flags)) 1077 1078 /* 1079 * After a symbol lookup has been resolved, the runtime linker needs to retain 1080 * information regarding the bound definition. An Sresult data structure is 1081 * used to provide this information. 1082 * 1083 * The symbol name (sr_name) may differ from the original referenced symbol if 1084 * a symbol capabilities family member has resolved the binding. The defining 1085 * object (sr_dmap) indicates the object in which the definition has been found. 1086 * The symbol table entry (sr_sym) defines the bound symbol definition. 1087 * 1088 * Note, a symbol lookup may start with one Sresult buffer, but underlying 1089 * routines (for example, those that probe filters) might employ their own 1090 * Sresult buffer. If a binding is allowed, the latter buffer may get inherited 1091 * by the former. Along with this chain of requests, binding info (binfo) and 1092 * not-found information (in_nfavl), may be passed between all the associated 1093 * functions. Hence, the binfo and in_nfavl data is not maintained as part of 1094 * a Sresult structure. 1095 */ 1096 struct sresult { 1097 const char *sr_name; /* symbol definition name */ 1098 Rt_map *sr_dmap; /* defining objects link-map */ 1099 Sym *sr_sym; /* symbol table pointer */ 1100 }; 1101 1102 #define SRESULT_INIT(sr, name) \ 1103 (void) (sr.sr_name = (name), sr.sr_dmap = NULL, sr.sr_sym = NULL) 1104 1105 /* 1106 * Define a system capabilities structure for maintaining the various 1107 * capabilities of the system. This structure follows the Objcapset definition 1108 * from libld.h, however the system can only have one platform or machine 1109 * hardware name, thus this structure is a little simpler. 1110 * 1111 * Note, the amd64 version of elf_rtbndr assumes that the sc_hw_1 value is at 1112 * offset zero. If you are changing this structure in a way that invalidates 1113 * this you need to update that code. 1114 */ 1115 typedef struct { 1116 elfcap_mask_t sc_hw_1; /* CA_SUNW_HW_1 capabilities */ 1117 elfcap_mask_t sc_sf_1; /* CA_SUNW_SF_1 capabilities */ 1118 elfcap_mask_t sc_hw_2; /* CA_SUNW_HW_2 capabilities */ 1119 char *sc_plat; /* CA_SUNW_PLAT capability */ 1120 size_t sc_platsz; /* and size */ 1121 char *sc_mach; /* CA_SUNW_MACH capability */ 1122 size_t sc_machsz; /* and size */ 1123 } Syscapset; 1124 1125 /* 1126 * Define a number of .plt lookup outcomes, for use in binding diagnostics. 1127 */ 1128 typedef enum { 1129 PLT_T_NONE = 0, 1130 PLT_T_21D, 1131 PLT_T_24D, 1132 PLT_T_U32, 1133 PLT_T_U44, 1134 PLT_T_FULL, 1135 PLT_T_FAR, 1136 PLT_T_NUM /* Must be last */ 1137 } Pltbindtype; 1138 1139 /* 1140 * Prototypes. 1141 */ 1142 extern ulong_t ld_entry_cnt; /* counter bumped on each entry to */ 1143 /* ld.so.1. */ 1144 extern Lm_list lml_main; /* main's link map list */ 1145 extern Lm_list lml_rtld; /* rtld's link map list */ 1146 extern Lm_list *lml_list[]; 1147 1148 extern Pltbindtype elf_plt_write(uintptr_t, uintptr_t, void *, uintptr_t, 1149 Xword); 1150 extern Rt_map *is_so_loaded(Lm_list *, const char *, int *); 1151 extern int lookup_sym(Slookup *, Sresult *, uint_t *, int *); 1152 extern int rt_dldump(Rt_map *, const char *, int, Addr); 1153 1154 #ifdef __cplusplus 1155 } 1156 #endif 1157 1158 #endif /* _RTLD_H */ 1159