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 * Copyright (c) 2017, Joyent, Inc. 25 */ 26 #ifndef _RTLD_H 27 #define _RTLD_H 28 29 /* 30 * Global include file for the runtime linker. 31 */ 32 #include <sys/mman.h> 33 #include <time.h> 34 #include <sgs.h> 35 #include <thread.h> 36 #include <synch.h> 37 #include <link.h> 38 #include <sys/avl.h> 39 #include <alist.h> 40 #include <libc_int.h> 41 #include <elfcap.h> 42 43 #ifdef _SYSCALL32 44 #include <inttypes.h> 45 #endif 46 47 #ifdef __cplusplus 48 extern "C" { 49 #endif 50 51 /* 52 * We use rtld_ino_t instead of ino_t so that we can get 53 * access to large inode values from 32-bit code. 54 */ 55 #ifdef _LP64 56 typedef ino_t rtld_ino_t; 57 #else 58 typedef ino64_t rtld_ino_t; 59 #endif 60 61 typedef struct rt_map Rt_map; 62 typedef struct slookup Slookup; 63 typedef struct sresult Sresult; 64 65 /* 66 * A binding descriptor. Establishes the binding relationship between two 67 * objects, the caller (originator) and the dependency (destination). 68 * 69 * Every relationship between two objects is tracked by a binding descriptor. 70 * This descriptor is referenced from a link-map's DEPENDS and CALLERS lists. 71 * Note, Aplist's are diagramed to fully expose the allocations required to 72 * establish the data structure relationships. 73 * 74 * Bnd_desc 75 * ---------- 76 * ------------| b_caller | 77 * | | b_depend | ---------- 78 * | | | | 79 * Rt_map | ---------- | Rt_map 80 * ---------- | ^ ^ | ---------- 81 * | | <-- | | --> | | 82 * | | -------- | | | | 83 * | DEPENDS | ----> | | | | -------- | | 84 * | | | | | | | | <---- | CALLERS | 85 * | | | | --- | | | | | 86 * | | | | --- | | | | 87 * | | -------- | | | | 88 * ---------- Aplist -------- ---------- 89 * Aplist 90 */ 91 typedef struct { 92 Rt_map *b_caller; /* caller (originator) of a binding */ 93 Rt_map *b_depend; /* dependency (destination) of a */ 94 /* binding */ 95 uint_t b_flags; /* relationship of caller to the */ 96 /* dependency */ 97 } Bnd_desc; 98 99 #define BND_NEEDED 0x0001 /* caller NEEDED the dependency */ 100 #define BND_REFER 0x0002 /* caller relocation references the */ 101 /* dependency */ 102 #define BND_FILTER 0x0004 /* binding identifies filter, used */ 103 /* for diagnostics only */ 104 /* 105 * Private structure for communication between rtld_db and rtld. 106 * 107 * We must bump the version number when ever an update in one of the 108 * structures/fields that rtld_db reads is updated. This hopefully permits 109 * rtld_db implementations of the future to recognize core files produced on 110 * older systems and deal with these core files accordingly. 111 * 112 * As of version 'R_RTLDDB_VERSION <= 2' the following fields were valid for 113 * core file examination (basically the public Link_map): 114 * 115 * ADDR() 116 * NAME() 117 * DYN() 118 * NEXT() 119 * PREV() 120 * 121 * Valid fields for R_RTLDDB_VERSION3 122 * 123 * PATHNAME() 124 * PADSTART() 125 * PADIMLEN() 126 * MSIZE() 127 * FLAGS() 128 * FLAGS1() 129 * 130 * Valid fields for R_RTLDDB_VERSION4 131 * 132 * TLSMODID() 133 * 134 * Valid fields for R_RTLDDB_VERSION5 135 * 136 * Added rtld_flags & FLG_RT_RELOCED to stable flags range 137 * 138 * Valid fields for R_RTLDDB_VERSION6 139 * 140 * rtd_dynlmlst converted from a List to APlist 141 */ 142 #define R_RTLDDB_VERSION1 1 /* base version level - used for core */ 143 /* file examination */ 144 #define R_RTLDDB_VERSION2 2 /* minor revision - not relevant for */ 145 /* core files */ 146 #define R_RTLDDB_VERSION3 3 147 #define R_RTLDDB_VERSION4 4 148 #define R_RTLDDB_VERSION5 5 149 #define R_RTLDDB_VERSION6 6 150 #define R_RTLDDB_VERSION R_RTLDDB_VERSION6 /* current version */ 151 152 typedef struct rtld_db_priv { 153 struct r_debug rtd_rdebug; /* original r_debug structure */ 154 Word rtd_version; /* version no. */ 155 size_t rtd_objpad; /* padding around mmap()ed objects */ 156 APlist **rtd_dynlmlst; /* pointer to dynlm_list pointer */ 157 } Rtld_db_priv; 158 159 #ifdef _SYSCALL32 160 typedef struct rtld_db_priv32 { 161 struct r_debug32 rtd_rdebug; /* original r_debug structure */ 162 Elf32_Word rtd_version; /* version no. */ 163 Elf32_Word rtd_objpad; /* padding around mmap()ed objects */ 164 Elf32_Addr rtd_dynlmlst; /* pointer to dynlm_list */ 165 } Rtld_db_priv32; 166 #endif /* _SYSCALL32 */ 167 168 /* 169 * External function definitions. ld.so.1 must convey information to libc in 170 * regards to threading. libc also provides routines for atexit() and message 171 * localization. libc provides the necessary interfaces via its RTLDINFO 172 * structure and/or later _ld_libc() calls. 173 * 174 * These external functions are maintained for each link-map list, and used 175 * where appropriate. The functions are associated with the object that 176 * provided them, so that should the object be deleted (say, from an alternative 177 * link-map), the functions can be removed. 178 */ 179 typedef struct { 180 Rt_map *lc_lmp; /* function provider */ 181 union { 182 int (*lc_func)(); /* external function pointer */ 183 uintptr_t lc_val; /* external value */ 184 char *lc_ptr; /* external character pointer */ 185 } lc_un; 186 } Lc_desc; 187 188 /* 189 * Link map list definition. Link-maps are used to describe each loaded object. 190 * Lists of these link-maps describe the various namespaces within a process. 191 * The process executable and its dependencies are maintained on the lml_main 192 * list. The runtime linker, and its dependencies are maintained on the 193 * lml_rtld list. Additional lists can be created (see dlmopen()) for such 194 * things as auditors and their dependencies. 195 * 196 * Each link-map list maintains an Alist of one, or more, linked lists of 197 * link-maps. For backward compatibility, the lm_head/lm_tail elements are 198 * initialized to the first linked-list of link-maps: 199 * 200 * Lm_list 201 * ---------- 202 * | lm_tail | ------------------------------------ 203 * | lm_head | -------------------- | 204 * | | | Rt_map | Rt_map 205 * | | | ------ | ------ 206 * | | Alist --> | | |--> | | 207 * | | --------- | | | -- | | 208 * | lm_lists | ----> | | | | | --> | | 209 * | | |---------| | | | | | | 210 * | | | lc_head | -- ------ | ------ 211 * | | | lc_tail | ------------------ 212 * | | |---------| 213 * ---------- | lc_head | 214 * | lc_tail | 215 * |---------| 216 * 217 * Multiple link-map lists exist to support the addition of lazy loaded 218 * families, filtee families, and dlopen() families. The intent of these 219 * lists is to insure that a family of objects that are to be loaded are 220 * fully relocatable, and hence usable, before they become part of the main 221 * (al_data[0]) link-map control list. This main link-map control list is 222 * the only list in existence when control is transferred to user code. 223 * 224 * During process initialization, the dynamic executable and its non-lazy 225 * dependencies are maintained on al_data[0]. If a new object is loaded, then 226 * this object is added to the next available control list [1], typically 227 * al_data[1]. Any dependencies of this object that have not already been 228 * loaded are added to the same control list. Once all of the objects on the 229 * new control list have been successfully relocated, the objects are moved from 230 * the new control list to the highest control list to which objects of the new 231 * control list bound to, typically al_data[1] to al_data[0]. 232 * 233 * Each loading scenario can be broken down as follows: 234 * 235 * setup() - only the initial link-map control list is used: 236 * i. create al_data[0] 237 * ii. add new link-map for main on al_data[0] 238 * iii. analyze al_data[0] to add all non-lazy dependencies 239 * iv. relocate al_data[0] dependencies. 240 * 241 * dlopen() - the initiator can only be the initial link-map control list: 242 * i. create al_data[1] from caller al_data[0] 243 * ii. add new link-map for the dlopen'ed object on al_data[1] 244 * iii. analyze al_data[1] to add all non-lazy dependencies 245 * iv. relocate al_data[1] dependencies, and move to al_data[0]. 246 * 247 * filtee and lazy loading processing - the initiator can be any link-map 248 * control list that is being relocated: 249 * i. create al_data[y] from caller al_data[x] 250 * ii. add new link-map for the new object on al_data[y] 251 * iii. analyze al_data[y] to add all non-lazy dependencies 252 * iv. relocate al_data[y] dependencies, and move to al_data[x]. 253 * 254 * This Alist therefore maintains a stack of link-map control lists. The newest 255 * link-map control list can locate symbols within any of the former lists, 256 * however, control is not passed to a former list until the newest lists 257 * processing is complete. Thus, objects can't bind to new objects until they 258 * have been fully analyzed and relocated. 259 * 260 * [1] Note, additional link-map control list creation occurs after the head 261 * link-map object (typically the dynamic executable) has been relocated. This 262 * staging is required to satisfy the binding requirements of copy relocations. 263 * Copy relocations, effectively, transfer the bindings of the copied data 264 * (say _iob in libc.so.1) to the copy location (_iob in the application). 265 * Thus an object that might bind to the original copy data must be redirected 266 * to the copy reference. As the knowledge of a copy relocation having taken 267 * place is only known after relocating the application, link-map control list 268 * additions are suspended until after this relocation has completed. 269 */ 270 typedef struct { 271 Rt_map *lc_head; 272 Rt_map *lc_tail; 273 APlist *lc_now; /* pending promoted bind-now objects */ 274 uint_t lc_flags; 275 } Lm_cntl; 276 277 #define LMC_FLG_ANALYZING 0x01 /* control list is being analyzed */ 278 #define LMC_FLG_RELOCATING 0x02 /* control list is being relocated */ 279 #define LMC_FLG_REANALYZE 0x04 /* repeat analysis (established when */ 280 /* interposers are added */ 281 282 struct lm_list { 283 /* 284 * BEGIN: Exposed to rtld_db - don't move, don't delete 285 */ 286 Rt_map *lm_head; /* linked list pointers to active */ 287 Rt_map *lm_tail; /* link-map list */ 288 APlist *lm_handle; /* not used by rtld_db - but spacing */ 289 /* is required for flags */ 290 Word lm_flags; 291 /* 292 * END: Exposed to rtld_db - don't move, don't delete 293 */ 294 Alist *lm_rti; /* list of RTLDINFO tables */ 295 Audit_list *lm_alp; /* audit list descriptor */ 296 avl_tree_t *lm_fpavl; /* avl tree of objects loaded */ 297 Alist *lm_lists; /* active and pending link-map lists */ 298 char ***lm_environ; /* pointer to environment array */ 299 Word lm_tflags; /* transferable flags */ 300 uint_t lm_obj; /* total number of objs on link-map */ 301 uint_t lm_init; /* new obj since last init processing */ 302 uint_t lm_lazy; /* number of objects with pending */ 303 /* lazy dependencies */ 304 uint_t lm_tls; /* new obj that require TLS */ 305 uint_t lm_lmid; /* unique link-map list identifier, */ 306 char *lm_lmidstr; /* and associated diagnostic string */ 307 Alist *lm_aud_cookies; /* local auditor cookies */ 308 Lc_desc lm_lcs[CI_MAX]; /* external libc functions */ 309 }; 310 311 #ifdef _SYSCALL32 312 struct lm_list32 { 313 /* 314 * BEGIN: Exposed to rtld_db - don't move, don't delete 315 */ 316 Elf32_Addr lm_head; 317 Elf32_Addr lm_tail; 318 Elf32_Addr lm_handle; 319 Elf32_Word lm_flags; 320 /* 321 * END: Exposed to rtld_db - don't move, don't delete 322 */ 323 Elf32_Addr lm_rti; 324 Elf32_Addr lm_fpavl; 325 Elf32_Addr lm_lists; 326 Elf32_Addr lm_environ; 327 Elf32_Word lm_tflags; 328 uint_t lm_obj; 329 uint_t lm_init; 330 uint_t lm_lazy; 331 uint_t lm_tls; 332 uint_t lm_lmid; 333 Elf32_Addr lm_lmidstr; 334 Elf32_Addr lm_aud_cookies; 335 Elf32_Addr lm_lcs[CI_MAX]; 336 }; 337 #endif /* _SYSCALL32 */ 338 339 /* 340 * Possible Link_map list flags (Lm_list.lm_flags) 341 */ 342 /* 343 * BEGIN: Exposed to rtld_db - don't move, don't delete 344 */ 345 #define LML_FLG_BASELM 0x00000001 /* primary link-map */ 346 #define LML_FLG_RTLDLM 0x00000002 /* rtld link-map */ 347 /* 348 * END: Exposed to rtld_db - don't move, don't delete 349 */ 350 #define LML_FLG_ACTAUDIT 0x00000004 /* audit activity posted */ 351 #define LML_FLG_PLTREL 0x00000008 /* deferred plt relocation */ 352 /* initialization (ld.so.1 */ 353 /* only) */ 354 #define LML_FLG_HOLDLOCK 0x00000010 /* hold the rtld mutex lock */ 355 #define LML_FLG_ENVIRON 0x00000020 /* environ var initialized */ 356 #define LML_FLG_INTRPOSE 0x00000040 /* interposing objs on list */ 357 #define LML_FLG_LOCAUDIT 0x00000080 /* local auditors exists for */ 358 /* this link-map list */ 359 #define LML_FLG_LOADAVAIL 0x00000100 /* load anything available */ 360 #define LML_FLG_IGNRELERR 0x00000200 /* ignore relocation errors - */ 361 /* internal for crle(1) */ 362 #define LML_FLG_STARTREL 0x00000400 /* relocation started */ 363 #define LML_FLG_ATEXIT 0x00000800 /* atexit processing */ 364 #define LML_FLG_OBJADDED 0x00001000 /* object(s) added */ 365 #define LML_FLG_OBJDELETED 0x00002000 /* object(s) deleted */ 366 #define LML_FLG_OBJREEVAL 0x00004000 /* existing object(s) needs */ 367 /* tsort reevaluation */ 368 #define LML_FLG_INTRPOSETSORT 0x00008000 /* interpose tsorting done */ 369 #define LML_FLG_AUDITNOTIFY 0x00010000 /* audit consistent required */ 370 #define LML_FLG_GROUPSEXIST 0x00020000 /* local groups exist */ 371 372 #define LML_FLG_TRC_LDDSTUB 0x00100000 /* identify lddstub */ 373 #define LML_FLG_TRC_ENABLE 0x00200000 /* tracing enabled (ldd) */ 374 #define LML_FLG_TRC_WARN 0x00400000 /* print warnings for undefs */ 375 #define LML_FLG_TRC_VERBOSE 0x00800000 /* verbose (versioning) trace */ 376 #define LML_FLG_TRC_SEARCH 0x01000000 /* trace search paths */ 377 #define LML_FLG_TRC_UNREF 0x02000000 /* trace unreferenced */ 378 /* dependencies */ 379 #define LML_FLG_TRC_UNUSED 0x04000000 /* trace unused dependencies */ 380 #define LML_FLG_TRC_INIT 0x08000000 /* print .init order */ 381 #define LML_FLG_TRC_NOUNRESWEAK 0x10000000 /* unresolved weak references */ 382 /* are not allowed */ 383 #define LML_FLG_TRC_NOPAREXT 0x20000000 /* unresolved PARENT/EXTERN */ 384 /* references are not */ 385 /* allowed */ 386 #define LML_MSK_TRC 0xfff00000 /* tracing mask */ 387 388 /* 389 * Possible Link_map transferable flags (Lm_list.lm_tflags), i.e., link-map 390 * list flags that can be propagated to any new link-map list created. 391 */ 392 #define LML_TFLG_NOLAZYLD 0x00000001 /* lazy loading disabled */ 393 #define LML_TFLG_NODIRECT 0x00000002 /* direct bindings disabled */ 394 #define LML_TFLG_NOAUDIT 0x00000004 /* auditing disabled */ 395 #define LML_TFLG_LOADFLTR 0x00000008 /* trigger filtee loading */ 396 397 #define LML_TFLG_AUD_PREINIT 0x00001000 /* preinit (audit) exists */ 398 #define LML_TFLG_AUD_OBJSEARCH 0x00002000 /* objsearch (audit) exists */ 399 #define LML_TFLG_AUD_OBJOPEN 0x00004000 /* objopen (audit) exists */ 400 #define LML_TFLG_AUD_OBJFILTER 0x00008000 /* objfilter (audit) exists */ 401 #define LML_TFLG_AUD_OBJCLOSE 0x00010000 /* objclose (audit) exists */ 402 #define LML_TFLG_AUD_SYMBIND 0x00020000 /* symbind (audit) exists */ 403 #define LML_TFLG_AUD_PLTENTER 0x00040000 /* pltenter (audit) exists */ 404 #define LML_TFLG_AUD_PLTEXIT 0x00080000 /* pltexit (audit) exists */ 405 #define LML_TFLG_AUD_ACTIVITY 0x00100000 /* activity (audit) exists */ 406 407 /* 408 * NOTE: Each auditing module establishes a set of audit flags, AFLAGS(), that 409 * define the auditing interfaces the module offers. These auditing flags are 410 * the LML_TFLG_AUD_ flags defined above. Global auditors result in setting 411 * the lm_tflags too. Local auditors only use the AFLAGS(). All tests for 412 * auditing inspect the lm_tflags and AFLAGS() for a specific auditing 413 * interface, and thus use the same flag to test for both types of auditors. 414 */ 415 #define LML_TFLG_AUD_MASK 0x0ffff000 /* audit interfaces mask */ 416 417 /* 418 * Define a Group Handle. 419 * 420 * The capability of ld.so.1 to associate a group of objects, look for symbols 421 * within that group, ensure that groups are isolated from one another (with 422 * regard to relocations), and to unload a group, centers around a handle. 423 * 424 * Dependencies can be added to an existing handle as the dependencies are 425 * lazily loaded. The core dependencies on the handle are the ldd(1) list of 426 * the referenced object. 427 * 428 * Handles can be created from: 429 * 430 * - a dlopen() request. This associates a caller to a reference object, 431 * and the referenced objects dependencies. This group of objects can 432 * then be inspected for symbols (dlsym()). 433 * - a filtering request. This associates a filter (caller) to a referenced 434 * object (filtee). The redirection of filter symbols to their filtee 435 * counterpart is essentially a dlsym() using the filtee's handle. 436 * 437 * The handle created for these events is referred to as a public handle. This 438 * handle tracks the referenced object, all of the dependencies of the 439 * referenced object, and the caller (parent). 440 * 441 * Presently, an object may have two handles, one requested with RTLD_FIRST 442 * and one without. 443 * 444 * A handle may be referenced by any number of callers (parents). A reference 445 * count tracks the number. A dlclose() operation drops the reference count, 446 * and when the count is zero, the handle is used to determine the family of 447 * objects to unload. As bindings may occur to objects on the handle from 448 * other handles, it may not be possible to remove a complete family of objects 449 * or the handle itself. Handles in this state are moved to an orphan list. 450 * A handle on the orphan list is taken off the orphan list if the associated 451 * object is reopened. Otherwise, the handle remains on the orphan list for 452 * the duration of the process. The orphan list is inspected any time objects 453 * are unloaded, to determine if the orphaned objects can also be unloaded. 454 * 455 * Handles can also be created for internal uses: 456 * 457 * - to promote objects to RTLD_NOW. 458 * - to establish families for symbol binding fallback, required when lazy 459 * loadable objects are still pending. 460 * 461 * The handle created for these events is referred to as a private handle. This 462 * handle does not need to track the caller (parent), and because of this, does 463 * not need to be considered during dlclose() operations, as the handle can not 464 * be referenced by callers outside of the referenced objects family. 465 * 466 * Note, a private handle is essentially a subset of a public handle. Should 467 * an internal operation require a private handle, and a public handle already 468 * exist, the public handle can be used. Should an external operation require 469 * a public handle, and a private handle exist, the private handle is promoted 470 * to a public handle. Any handle that gets created will remain in existence 471 * for the life time of the referenced object. 472 * 473 * Objects can be dlopened using RTLD_NOW. This attribute requires that all 474 * relocations of the object, and its dependencies are processed immediately, 475 * before return to the caller. Typically, an object is loaded without 476 * RTLD_NOW, and procedure linkage relocations are satisfied when their 477 * associated function is first called. If an object is already loaded, and an 478 * RTLD_NOW request is made, then the object, and its dependencies, most undergo 479 * additional relocation processing. This promotion from lazy binding to 480 * immediate binding is carried out using handles, as the handle defines the 481 * dependencies that must be processed. 482 * 483 * To ensure that objects within a lazy loadable environment can be relocated, 484 * no matter whether the objects have their dependencies described completely, 485 * a symbol lookup fallback is employed. Any pending lazy loadable objects are 486 * loaded, and a handle established to search the object and it's dependencies 487 * for the required symbol. 488 * 489 * A group handle (and its associated group descriptors), is referenced from 490 * a link-map's HANDLES and GROUPS lists. Note, Aplist's are diagramed to 491 * fully expose the allocations required to establish the data structure 492 * relationships. 493 * 494 * Grp_desc 495 * Alist 496 * ----------- 497 * --> | | 498 * | |-----------| 499 * | | gd_depend | --------- 500 * | | | | 501 * | |-----------| | 502 * --------|--- | gd_depend | | 503 * | | | (parent) | | 504 * | | |-----------| | 505 * | | | gd_depend | | 506 * | | | | | 507 * | | | | | 508 * | | ----------- | 509 * | | | 510 * | | Grp_hdl | 511 * | | ----------- | 512 * | -- | gh_depends | | 513 * | --------- | gh_ownlmp | | 514 * | | | | | 515 * | | | | | 516 * | | | | | 517 * Rt_map | | ------------ | Rt_map 518 * ---------- | | ^ ^ | ---------- 519 * | | <- | | | --> | | 520 * | | <--- -------- | | | | 521 * | HANDLES | ----> | | | | -------- | | 522 * | | | | | | | | <---- | GROUPS | 523 * | | | | --- | | | | | 524 * | | | | --- | | | | 525 * | | -------- | | | | 526 * ---------- Aplist -------- ---------- 527 * Aplist 528 */ 529 typedef struct { 530 Alist *gh_depends; /* handle dependency list */ 531 Rt_map *gh_ownlmp; /* handle owners link-map */ 532 Lm_list *gh_ownlml; /* handle owners link-map list */ 533 uint_t gh_refcnt; /* handle reference count */ 534 uint_t gh_flags; /* handle flags (GPH_ values) */ 535 } Grp_hdl; 536 537 /* 538 * Define the two categories of handle. 539 */ 540 #define GPH_PUBLIC 0x0001 /* handle returned to caller(s) */ 541 #define GPH_PRIVATE 0x0002 /* handle used internally */ 542 543 /* 544 * Define any flags that affects how the handle is used. 545 */ 546 #define GPH_ZERO 0x0010 /* special handle for dlopen(0) */ 547 #define GPH_LDSO 0x0020 /* special handle for ld.so.1 */ 548 #define GPH_FIRST 0x0040 /* dlsym() can only use originating */ 549 /* dependency */ 550 #define GPH_FILTEE 0x0080 /* handle identifies a filtee, used */ 551 /* for diagnostics only */ 552 /* 553 * Define any state that is associated with the handle. 554 */ 555 #define GPH_INITIAL 0x0100 /* handle is initialized */ 556 557 /* 558 * Define a Group Descriptor. 559 * 560 * Each dependency associated with a group handle is maintained by a group 561 * descriptor. The descriptor defines the associated dependency together with 562 * flags that indicate how the dependency can be used. 563 */ 564 typedef struct { 565 Rt_map *gd_depend; /* dependency */ 566 uint_t gd_flags; /* dependency flags (GPD_ values) */ 567 } Grp_desc; 568 569 #define GPD_DLSYM 0x0001 /* dependency available to dlsym() */ 570 #define GPD_RELOC 0x0002 /* dependency available to satisfy */ 571 /* relocation binding */ 572 #define GPD_ADDEPS 0x0004 /* dependencies of this dependency */ 573 /* should be added to handle */ 574 #define GPD_PARENT 0x0008 /* dependency is a parent */ 575 #define GPD_FILTER 0x0010 /* dependency is our filter */ 576 #define GPD_REMOVE 0x0100 /* descriptor is a candidate for */ 577 /* removal from the group */ 578 579 /* 580 * Define threading structures. For compatibility with libthread (T1_VERSION 1 581 * and TI_VERSION 2) our locking structure is sufficient to hold a mutex or a 582 * readers/writers lock. 583 */ 584 typedef struct { 585 union { 586 mutex_t l_mutex; 587 rwlock_t l_rwlock; 588 } u; 589 } Rt_lock; 590 591 typedef cond_t Rt_cond; 592 593 /* 594 * Define a dynamic section information descriptor. This parallels the entries 595 * in the .dynamic section and holds auxiliary information to implement lazy 596 * loading and filtee processing. 597 */ 598 typedef struct { 599 uint_t di_flags; 600 void *di_info; 601 const char *di_name; 602 } Dyninfo; 603 604 #define FLG_DI_STDFLTR 0x00001 /* .dynamic entry for DT_FILTER */ 605 #define FLG_DI_AUXFLTR 0x00002 /* .dynamic entry for DT_AUXILIARY */ 606 #define FLG_DI_SYMFLTR 0x00004 /* .dynamic entry for DT_SYMFILTER */ 607 /* and DT_SYMAUXILIARY */ 608 #define MSK_DI_FILTER 0x0000f /* mask for all filter possibilities */ 609 610 #define FLG_DI_POSFLAG1 0x00010 /* .dynamic entry for DT_POSFLAG_1 */ 611 #define FLG_DI_NEEDED 0x00020 /* .dynamic entry for DT_NEEDED */ 612 #define FLG_DI_REGISTER 0x00040 /* .dynamic entry for DT_REGISTER */ 613 #define FLG_DI_IGNORE 0x00080 /* .dynamic entry should be ignored */ 614 615 #define FLG_DI_LAZY 0x00100 /* lazy needed entry, preceded by */ 616 /* DF_P1_LAZYLOAD (DT_POSFLAG_1) */ 617 #define FLG_DI_GROUP 0x00200 /* group needed entry, preceded by */ 618 /* DF_P1_GROUPPERM (DT_POSFLAG_1) */ 619 #define FLG_DI_DEFERRED 0x00400 /* deferred needed entry, preceded by */ 620 /* DF_P1_DEFERRED (DT_POSFLAG_1) */ 621 622 #define FLG_DI_LAZYFAIL 0x01000 /* the lazy loading of this entry */ 623 /* failed */ 624 #define FLG_DI_LDD_DONE 0x02000 /* entry has been processed (ldd) */ 625 #define FLG_DI_DEF_DONE 0x04000 /* entry has been processed (dlinfo) */ 626 627 /* 628 * Data structure to track AVL tree of pathnames. This structure provides the 629 * basis of both the "not-found" node tree, and the "full-path" node tree. Both 630 * of these trees persist for the life of a process, although the "not-found" 631 * tree may be moved aside during a dlopen() or dlsym() fall back operation. 632 */ 633 typedef struct { 634 const char *pn_name; /* path name */ 635 avl_node_t pn_avl; /* avl book-keeping (see SGSOFFSETOF) */ 636 uint_t pn_hash; /* path name hash value */ 637 } PathNode; 638 639 /* 640 * Data structure to track AVL tree for full path names of objects that are 641 * loaded into memory. 642 */ 643 typedef struct { 644 PathNode fpn_node; /* path node */ 645 Rt_map *fpn_lmp; /* object link-map */ 646 } FullPathNode; 647 648 /* 649 * A given link-map can hold either a supplier or receiver copy 650 * relocation list, but not both. This union is used to overlap 651 * the space used for the two lists. 652 */ 653 typedef union { 654 Alist *rtc_r; /* receiver list (Rel_copy) */ 655 APlist *rtc_s; /* supplier list (Rt_map *) */ 656 } Rt_map_copy; 657 658 659 /* 660 * Link-map definition. 661 */ 662 struct rt_map { 663 /* 664 * BEGIN: Exposed to rtld_db - don't move, don't delete 665 */ 666 Link_map rt_public; /* public data */ 667 const char *rt_pathname; /* full pathname of loaded object */ 668 ulong_t rt_padstart; /* start of image (including padding) */ 669 ulong_t rt_padimlen; /* size of image (including padding */ 670 ulong_t rt_msize; /* total memory reservation range */ 671 uint_t rt_flags; /* state flags, see FLG below */ 672 uint_t rt_flags1; /* state flags1, see FL1 below */ 673 ulong_t rt_tlsmodid; /* TLS module id */ 674 /* 675 * END: Exposed to rtld_db - don't move, don't delete 676 */ 677 APlist *rt_alias; /* list of linked file names */ 678 APlist *rt_fpnode; /* list of FullPathNode AVL nodes */ 679 char *rt_runpath; /* LD_RUN_PATH and its equivalent */ 680 Alist *rt_runlist; /* Pdesc structures */ 681 APlist *rt_depends; /* list of dependencies */ 682 APlist *rt_callers; /* list of callers */ 683 APlist *rt_handles; /* dlopen handles */ 684 APlist *rt_groups; /* groups we're a member of */ 685 struct fct *rt_fct; /* file class table for this object */ 686 void *rt_priv; /* private data, object type specific */ 687 Lm_list *rt_list; /* link map list we belong to */ 688 uint_t rt_objfltrndx; /* object filtees .dynamic index */ 689 uint_t rt_symsfltrcnt; /* number of standard symbol filtees */ 690 uint_t rt_symafltrcnt; /* number of auxiliary symbol filtees */ 691 int rt_mode; /* usage mode, see RTLD mode flags */ 692 int rt_sortval; /* temporary buffer to traverse graph */ 693 uint_t rt_cycgroup; /* cyclic group */ 694 dev_t rt_stdev; /* device id and inode number for .so */ 695 rtld_ino_t rt_stino; /* multiple inclusion checks */ 696 const char *rt_origname; /* original pathname of loaded object */ 697 size_t rt_dirsz; /* and its size */ 698 size_t rt_lmsize; /* size of the link-map allocation */ 699 Rt_map_copy rt_copy; /* list of copy relocations */ 700 Audit_desc *rt_auditors; /* audit descriptor array */ 701 Audit_info *rt_audinfo; /* audit information descriptor */ 702 Syminfo *rt_syminfo; /* elf .syminfo section - here */ 703 /* because it is checked in */ 704 /* common code */ 705 Addr *rt_initarray; /* .init_array table */ 706 Addr *rt_finiarray; /* .fini_array table */ 707 Addr *rt_preinitarray; /* .preinit_array table */ 708 mmapobj_result_t *rt_mmaps; /* array of mapping information */ 709 uint_t rt_mmapcnt; /* and associated number */ 710 uint_t rt_initarraysz; /* size of .init_array table */ 711 uint_t rt_finiarraysz; /* size of .fini_array table */ 712 uint_t rt_preinitarraysz; /* size of .preinit_array table */ 713 Dyninfo *rt_dyninfo; /* .dynamic information descriptors */ 714 uint_t rt_dyninfocnt; /* count of dyninfo entries */ 715 uint_t rt_relacount; /* no. of RELATIVE relocations */ 716 uint_t rt_idx; /* hold index within linkmap list */ 717 uint_t rt_lazy; /* number of lazy dependencies */ 718 /* pending */ 719 Cap *rt_cap; /* capabilities data */ 720 Capchain *rt_capchain; /* capabilities chain data */ 721 uint_t rt_cntl; /* link-map control list we belong to */ 722 uint_t rt_aflags; /* auditor flags, see LML_TFLG_AUD_ */ 723 Rt_cond rt_cv; /* for waiting on flags changes */ 724 Rt_lock rt_lock; /* for coordinating flags changes */ 725 /* address of _init */ 726 thread_t rt_init_thread; /* thread id in this lm's _init */ 727 void (*rt_init)(void); 728 /* address of _fini */ 729 void (*rt_fini)(void); 730 /* link map symbol interpreter */ 731 int (*rt_symintp)(Slookup *, Sresult *, uint_t *, int *); 732 }; 733 734 #ifdef _SYSCALL32 735 /* 736 * Structure to allow 64-bit rtld_db to read 32-bit processes out of procfs. 737 */ 738 typedef union { 739 uint32_t rtc_r; 740 uint32_t rtc_s; 741 } Rt_map_copy32; 742 743 typedef struct rt_map32 { 744 /* 745 * BEGIN: Exposed to rtld_db - don't move, don't delete 746 */ 747 Link_map32 rt_public; 748 uint32_t rt_pathname; 749 uint32_t rt_padstart; 750 uint32_t rt_padimlen; 751 uint32_t rt_msize; 752 uint32_t rt_flags; 753 uint32_t rt_flags1; 754 uint32_t rt_tlsmodid; 755 /* 756 * END: Exposed to rtld_db - don't move, don't delete 757 */ 758 uint32_t rt_alias; 759 uint32_t rt_fpnode; 760 uint32_t rt_runpath; 761 uint32_t rt_runlist; 762 uint32_t rt_depends; 763 uint32_t rt_callers; 764 uint32_t rt_handles; 765 uint32_t rt_groups; 766 uint32_t rt_fct; 767 uint32_t rt_priv; 768 uint32_t rt_list; 769 uint32_t rt_objfltrndx; 770 uint32_t rt_symsfltrcnt; 771 uint32_t rt_symafltrcnt; 772 int32_t rt_mode; 773 int32_t rt_sortval; 774 uint32_t rt_cycgroup; 775 uint32_t rt_stdev; 776 uint32_t rt_stino; 777 uint32_t rt_origname; 778 uint32_t rt_dirsz; 779 Rt_map_copy32 rt_copy; 780 uint32_t rt_auditors; 781 uint32_t rt_audinfo; 782 uint32_t rt_syminfo; 783 uint32_t rt_initarray; 784 uint32_t rt_finiarray; 785 uint32_t rt_preinitarray; 786 uint32_t rt_mmaps; 787 uint32_t rt_mmapcnt; 788 uint32_t rt_initarraysz; 789 uint32_t rt_finiarraysz; 790 uint32_t rt_preinitarraysz; 791 uint32_t rt_dyninfo; 792 uint32_t rt_dyninfocnt; 793 uint32_t rt_relacount; 794 uint32_t rt_idx; 795 uint32_t rt_lazy; 796 uint32_t rt_cap; 797 uint32_t rt_capchain; 798 uint32_t rt_cntl; 799 uint32_t rt_aflags; 800 uint32_t rt_init; 801 uint32_t rt_fini; 802 uint32_t rt_symintp; 803 } Rt_map32; 804 805 #endif /* _SYSCALL32 */ 806 807 /* 808 * Link map state flags. 809 */ 810 /* 811 * BEGIN: Exposed to rtld_db - don't move, don't delete 812 */ 813 #define FLG_RT_ISMAIN 0x00000001 /* object represents main executable */ 814 #define FLG_RT_IMGALLOC 0x00000002 /* image is allocated (not mmap'ed) */ 815 /* 816 * Available for r_debug version >= R_RTLDDB_VERSION5 817 */ 818 #define FLG_RT_RELOCED 0x00000004 /* object has been relocated */ 819 /* 820 * END: Exposed to rtld_db - don't move, don't delete 821 */ 822 #define FLG_RT_SETGROUP 0x00000008 /* group establishment required */ 823 #define FLG_RT_CAP 0x00000010 /* process $CAPABILITY expansion */ 824 #define FLG_RT_OBJECT 0x00000020 /* object processing (ie. .o's) */ 825 #define FLG_RT_NEWLOAD 0x00000040 /* object is newly loaded */ 826 #define FLG_RT_NODUMP 0x00000080 /* object can't be dldump(3x)'ed */ 827 #define FLG_RT_DELETE 0x00000100 /* object can be deleted */ 828 #define FLG_RT_ANALYZED 0x00000200 /* object has been analyzed */ 829 #define FLG_RT_INITDONE 0x00000400 /* objects .init has been completed */ 830 #define FLG_RT_TRANS 0x00000800 /* object is acting as a translator */ 831 #define FLG_RT_FIXED 0x00001000 /* image location is fixed */ 832 #define FLG_RT_PRELOAD 0x00002000 /* object was preloaded */ 833 #define FLG_RT_ALTER 0x00004000 /* alternative object used */ 834 #define FLG_RT_LOADFLTR 0x00008000 /* trigger filtee loading */ 835 #define FLG_RT_AUDIT 0x00010000 /* object is an auditor */ 836 #define FLG_RT_MODESET 0x00020000 /* MODE() has been initialized */ 837 #define FLG_RT_ANALZING 0x00040000 /* object is being analyzed */ 838 #define FLG_RT_INITFRST 0x00080000 /* execute .init first */ 839 #define FLG_RT_NOOPEN 0x00100000 /* dlopen() not allowed */ 840 #define FLG_RT_FINICLCT 0x00200000 /* fini has been collected (tsort) */ 841 #define FLG_RT_INITCALL 0x00400000 /* objects .init has been called */ 842 #define FLG_RT_OBJINTPO 0x00800000 /* object is a global interposer */ 843 #define FLG_RT_SYMINTPO 0x01000000 /* object contains symbol interposer */ 844 #define MSK_RT_INTPOSE 0x01800000 /* mask for all interposer */ 845 /* possibilities */ 846 #define FLG_RT_MOVE 0x02000000 /* object needs move operation */ 847 #define FLG_RT_RELOCING 0x04000000 /* object is being relocated */ 848 #define FLG_RT_REGSYMS 0x08000000 /* object has DT_REGISTER entries */ 849 #define FLG_RT_INITCLCT 0x10000000 /* init has been collected (tsort) */ 850 #define FLG_RT_PUBHDL 0x20000000 /* generate a handle for this object */ 851 #define FLG_RT_PRIHDL 0x40000000 /* either public or private */ 852 853 #define FL1_RT_COPYTOOK 0x00000001 /* copy relocation taken */ 854 #define FL1_RT_ALTCHECK 0x00000002 /* alternative system capabilities */ 855 /* checked */ 856 #define FL1_RT_ALTCAP 0x00000004 /* alternative system capabilities */ 857 /* should be used */ 858 #define FL1_RT_CONFSET 0x00000008 /* object was loaded by crle(1) */ 859 #define FL1_RT_NODEFLIB 0x00000010 /* ignore default library search */ 860 #define FL1_RT_ENDFILTE 0x00000020 /* filtee terminates filters search */ 861 #define FL1_RT_DISPREL 0x00000040 /* object has *disp* relocation */ 862 #define FL1_RT_DTFLAGS 0x00000080 /* DT_FLAGS element exists */ 863 #define FL1_RT_LDDSTUB 0x00000100 /* identify lddstub */ 864 #define FL1_RT_NOINIFIN 0x00000200 /* no .init or .fini exists */ 865 #define FL1_RT_USED 0x00000400 /* symbol referenced from this object */ 866 #define FL1_RT_SYMBOLIC 0x00000800 /* DF_SYMBOLIC was set - use */ 867 /* symbolic sym resolution */ 868 #define FL1_RT_OBJSFLTR 0x00001000 /* object is acting as a standard */ 869 #define FL1_RT_OBJAFLTR 0x00002000 /* or auxiliary filter */ 870 #define FL1_RT_SYMSFLTR 0x00004000 /* symbol is acting as a standard */ 871 #define FL1_RT_SYMAFLTR 0x00008000 /* or auxiliary filter */ 872 #define MSK_RT_FILTER 0x0000f000 /* mask for all filter possibilities */ 873 874 #define FL1_RT_TLSADD 0x00010000 /* objects TLS has been registered */ 875 #define FL1_RT_TLSSTAT 0x00020000 /* object requires static TLS */ 876 #define FL1_RT_DIRECT 0x00040000 /* object has DIRECT bindings enabled */ 877 #define FL1_RT_GLOBAUD 0x00080000 /* establish global auditing */ 878 #define FL1_RT_DEPAUD 0x00100000 /* audit library from DT_DEPAUDIT */ 879 880 /* 881 * Flags for the tls_modactivity() routine 882 */ 883 #define TM_FLG_MODADD 0x01 /* call tls_modadd() interface */ 884 #define TM_FLG_MODREM 0x02 /* call tls_modrem() interface */ 885 886 /* 887 * Macros for getting to exposed, link_map data (R_RTLDDB_VERSION <= 2). 888 */ 889 #define ADDR(X) ((X)->rt_public.l_addr) 890 #define NAME(X) ((X)->rt_public.l_name) 891 #define DYN(X) ((X)->rt_public.l_ld) 892 #define NEXT(X) ((X)->rt_public.l_next) 893 #define PREV(X) ((X)->rt_public.l_prev) 894 #define REFNAME(X) ((X)->rt_public.l_refname) 895 896 /* 897 * An Rt_map starts with a Link_map, followed by other information. 898 * ld.so.1 allocates Rt_map structures, and then casts them to Link_map, 899 * and back, depending on context. 900 * 901 * On some platforms, Rt_map can have a higher alignment requirement 902 * than Link_map. On such platforms, the cast from Link_map to Rt_map will 903 * draw an E_BAD_PTR_CAST_ALIGN warning from lint. Since we allocate 904 * the memory as the higher alignment Rt_map, we know that this is a safe 905 * conversion. The LINKMAP_TO_RTMAP macro is used to handle the conversion 906 * in a manner that satisfies lint. 907 */ 908 #ifdef lint 909 #define LINKMAP_TO_RTMAP(X) (Rt_map *)(void *)(X) 910 #else 911 #define LINKMAP_TO_RTMAP(X) (Rt_map *)(X) 912 #endif 913 914 /* 915 * Convenience macros for the common case of using 916 * NEXT()/PREV() and casting the result to (Rt_map *) 917 */ 918 #define NEXT_RT_MAP(X) LINKMAP_TO_RTMAP(NEXT(X)) 919 #define PREV_RT_MAP(X) LINKMAP_TO_RTMAP(PREV(X)) 920 921 /* 922 * Macros for getting to exposed, link_map data (R_RTLDDB_VERSION3). 923 */ 924 #define PATHNAME(X) ((X)->rt_pathname) 925 #define PADSTART(X) ((X)->rt_padstart) 926 #define PADIMLEN(X) ((X)->rt_padimlen) 927 #define MSIZE(X) ((X)->rt_msize) 928 #define FLAGS(X) ((X)->rt_flags) 929 #define FLAGS1(X) ((X)->rt_flags1) 930 931 /* 932 * Macros for getting to exposed, link_map data (R_RTLDDB_VERSION4). 933 */ 934 #define TLSMODID(X) ((X)->rt_tlsmodid) 935 936 /* 937 * Macros for getting to unexposed, link-map data. 938 */ 939 #define LMSIZE(X) ((X)->rt_lmsize) 940 #define AFLAGS(X) ((X)->rt_aflags) 941 #define ALIAS(X) ((X)->rt_alias) 942 #define FPNODE(X) ((X)->rt_fpnode) 943 #define INIT(X) ((X)->rt_init) 944 #define FINI(X) ((X)->rt_fini) 945 #define RPATH(X) ((X)->rt_runpath) 946 #define RLIST(X) ((X)->rt_runlist) 947 #define DEPENDS(X) ((X)->rt_depends) 948 #define CALLERS(X) ((X)->rt_callers) 949 #define HANDLES(X) ((X)->rt_handles) 950 #define GROUPS(X) ((X)->rt_groups) 951 #define FCT(X) ((X)->rt_fct) 952 #define SYMINTP(X) ((X)->rt_symintp) 953 #define LIST(X) ((X)->rt_list) 954 #define OBJFLTRNDX(X) ((X)->rt_objfltrndx) 955 #define SYMSFLTRCNT(X) ((X)->rt_symsfltrcnt) 956 #define SYMAFLTRCNT(X) ((X)->rt_symafltrcnt) 957 #define MODE(X) ((X)->rt_mode) 958 #define SORTVAL(X) ((X)->rt_sortval) 959 #define CYCGROUP(X) ((X)->rt_cycgroup) 960 #define STDEV(X) ((X)->rt_stdev) 961 #define STINO(X) ((X)->rt_stino) 962 #define ORIGNAME(X) ((X)->rt_origname) 963 #define DIRSZ(X) ((X)->rt_dirsz) 964 #define COPY_R(X) ((X)->rt_copy.rtc_r) 965 #define COPY_S(X) ((X)->rt_copy.rtc_s) 966 #define AUDITORS(X) ((X)->rt_auditors) 967 #define AUDINFO(X) ((X)->rt_audinfo) 968 #define SYMINFO(X) ((X)->rt_syminfo) 969 #define INITARRAY(X) ((X)->rt_initarray) 970 #define FINIARRAY(X) ((X)->rt_finiarray) 971 #define PREINITARRAY(X) ((X)->rt_preinitarray) 972 #define MMAPS(X) ((X)->rt_mmaps) 973 #define MMAPCNT(X) ((X)->rt_mmapcnt) 974 #define INITARRAYSZ(X) ((X)->rt_initarraysz) 975 #define FINIARRAYSZ(X) ((X)->rt_finiarraysz) 976 #define PREINITARRAYSZ(X) ((X)->rt_preinitarraysz) 977 #define DYNINFO(X) ((X)->rt_dyninfo) 978 #define DYNINFOCNT(X) ((X)->rt_dyninfocnt) 979 #define RELACOUNT(X) ((X)->rt_relacount) 980 #define IDX(X) ((X)->rt_idx) 981 #define LAZY(X) ((X)->rt_lazy) 982 #define CNTL(X) ((X)->rt_cntl) 983 #define CAP(X) ((X)->rt_cap) 984 #define CAPCHAIN(X) ((X)->rt_capchain) 985 986 /* 987 * Flags for tsorting. 988 */ 989 #define RT_SORT_FWD 0x01 /* topological sort (.fini) */ 990 #define RT_SORT_REV 0x02 /* reverse topological sort (.init) */ 991 #define RT_SORT_DELETE 0x10 /* process FLG_RT_DELETE objects */ 992 /* only (called via dlclose()) */ 993 #define RT_SORT_INTPOSE 0x20 /* process interposer objects */ 994 995 /* 996 * Flags for lookup_sym (and hence find_sym) routines. 997 */ 998 #define LKUP_DEFT 0x0000 /* simple lookup request */ 999 #define LKUP_SPEC 0x0001 /* special ELF lookup (allows address */ 1000 /* resolutions to plt[] entries) */ 1001 #define LKUP_LDOT 0x0002 /* indicates the original A_OUT */ 1002 /* symbol had a leading `.' */ 1003 #define LKUP_FIRST 0x0004 /* lookup symbol in first link map */ 1004 /* only */ 1005 #define LKUP_COPY 0x0008 /* lookup symbol for a COPY reloc, do */ 1006 /* not bind to symbol at head */ 1007 #define LKUP_STDRELOC 0x0010 /* lookup originates from a standard */ 1008 /* relocation (elf_reloc()) */ 1009 #define LKUP_SELF 0x0020 /* lookup symbol in ourself - undef */ 1010 /* is valid */ 1011 #define LKUP_WEAK 0x0040 /* relocation reference is weak */ 1012 #define LKUP_NEXT 0x0080 /* request originates from RTLD_NEXT */ 1013 #define LKUP_NODESCENT 0x0100 /* don't descend through dependencies */ 1014 #define LKUP_NOFALLBACK 0x0200 /* don't fall back to loading */ 1015 /* pending lazy dependencies */ 1016 #define LKUP_DIRECT 0x0400 /* direct binding request */ 1017 #define LKUP_SYMNDX 0x0800 /* establish symbol index */ 1018 #define LKUP_SINGLETON 0x1000 /* search for a singleton symbol */ 1019 #define LKUP_STANDARD 0x2000 /* standard lookup - originated from */ 1020 /* head link-map element */ 1021 #define LKUP_WORLD 0x4000 /* ensure world lookup */ 1022 #define LKUP_DLSYM 0x8000 /* lookup stems from dlsym() request */ 1023 1024 /* 1025 * For the runtime linker to perform a symbol search, a number of data items 1026 * related to the search are required. An Slookup data structure is used to 1027 * convey this data to lookup_sym(), and in special cases, to other core 1028 * routines that provide the implementation details for lookup_sym() 1029 * 1030 * The symbol name (sl_name), the caller (sl_cmap), and the link-map from which 1031 * to start the search (sl_imap) are fundamental to the symbol search. The 1032 * initial search link-map might get modified by the core routines that provide 1033 * the implementation details for lookup_sym(). This modification accommodates 1034 * requirements such as processing a handle, direct binding and interposition. 1035 * The association between the caller and the potential destination also 1036 * determines whether the destination is a candidate to search. 1037 * 1038 * The lookup identifier (sl_id) is used to identify a runtime linker operation. 1039 * Within this operation, any lazy loads that fail are not re-examined. This 1040 * technique keeps the overhead of processing a failed lazy load to a minimum. 1041 * 1042 * Symbol searches that originate from a relocation record are accompanied by 1043 * the relocation index (sl_rsymndx), the symbol reference (sl_rsym) and 1044 * possibly the relocation type (sl_rtype). This data provides for determining 1045 * lazy loading, direct binding, and special symbol processing requirements 1046 * such as copy relocations and singleton lookup. 1047 * 1048 * The symbols hash value is computed by lookup_sym, and propagated throughout 1049 * the search engine. Note, occasionally the Slookup data is passed to a core 1050 * routine that provides the implementation details for lookup_sym(), ie. 1051 * elf_find_sym(), in which case the caller must initialize the hash value. 1052 * 1053 * The symbols binding information is established by lookup_sym() when the 1054 * symbols relocation type is supplied. Weak bindings allow relocations to 1055 * be set to zero should a symbol lookup fail. 1056 * 1057 * The flags allow the caller to control aspects of the search, including the 1058 * interpretation of copy relocations, etc. Note, a number of flag settings 1059 * are established in lookup_sym() from attributes of the symbol reference. 1060 */ 1061 struct slookup { 1062 const char *sl_name; /* symbol name */ 1063 Rt_map *sl_cmap; /* callers link-map */ 1064 Rt_map *sl_imap; /* initial link-map to search */ 1065 ulong_t sl_id; /* identifier for this lookup */ 1066 ulong_t sl_hash; /* symbol hash value */ 1067 ulong_t sl_rsymndx; /* referencing reloc symndx */ 1068 Sym *sl_rsym; /* referencing symbol */ 1069 uchar_t sl_rtype; /* relocation type associate with */ 1070 /* symbol */ 1071 uchar_t sl_bind; /* symbols binding (returned) */ 1072 uint_t sl_flags; /* lookup flags */ 1073 }; 1074 1075 #define SLOOKUP_INIT(sl, name, cmap, imap, id, hash, rsymndx, rsym, rtype, \ 1076 flags) \ 1077 (void) (sl.sl_name = (name), sl.sl_cmap = (cmap), sl.sl_imap = (imap), \ 1078 sl.sl_id = (id), sl.sl_hash = (hash), sl.sl_rsymndx = (rsymndx), \ 1079 sl.sl_rsym = (rsym), sl.sl_rtype = (rtype), sl.sl_bind = 0, \ 1080 sl.sl_flags = (flags)) 1081 1082 /* 1083 * After a symbol lookup has been resolved, the runtime linker needs to retain 1084 * information regarding the bound definition. An Sresult data structure is 1085 * used to provide this information. 1086 * 1087 * The symbol name (sr_name) may differ from the original referenced symbol if 1088 * a symbol capabilities family member has resolved the binding. The defining 1089 * object (sr_dmap) indicates the object in which the definition has been found. 1090 * The symbol table entry (sr_sym) defines the bound symbol definition. 1091 * 1092 * Note, a symbol lookup may start with one Sresult buffer, but underlying 1093 * routines (for example, those that probe filters) might employ their own 1094 * Sresult buffer. If a binding is allowed, the latter buffer may get inherited 1095 * by the former. Along with this chain of requests, binding info (binfo) and 1096 * not-found information (in_nfavl), may be passed between all the associated 1097 * functions. Hence, the binfo and in_nfavl data is not maintained as part of 1098 * a Sresult structure. 1099 */ 1100 struct sresult { 1101 const char *sr_name; /* symbol definition name */ 1102 Rt_map *sr_dmap; /* defining objects link-map */ 1103 Sym *sr_sym; /* symbol table pointer */ 1104 }; 1105 1106 #define SRESULT_INIT(sr, name) \ 1107 (void) (sr.sr_name = (name), sr.sr_dmap = NULL, sr.sr_sym = NULL) 1108 1109 /* 1110 * Define a system capabilities structure for maintaining the various 1111 * capabilities of the system. This structure follows the Objcapset definition 1112 * from libld.h, however the system can only have one platform or machine 1113 * hardware name, thus this structure is a little simpler. 1114 * 1115 * Note, the amd64 version of elf_rtbndr assumes that the sc_hw_1 value is at 1116 * offset zero and sc_hw_2 is at offset 8. If you are changing this structure 1117 * in a way that invalidates this, you need to update that code. 1118 */ 1119 typedef struct { 1120 elfcap_mask_t sc_hw_1; /* CA_SUNW_HW_1 capabilities */ 1121 elfcap_mask_t sc_sf_1; /* CA_SUNW_SF_1 capabilities */ 1122 elfcap_mask_t sc_hw_2; /* CA_SUNW_HW_2 capabilities */ 1123 char *sc_plat; /* CA_SUNW_PLAT capability */ 1124 size_t sc_platsz; /* and size */ 1125 char *sc_mach; /* CA_SUNW_MACH capability */ 1126 size_t sc_machsz; /* and size */ 1127 } Syscapset; 1128 1129 /* 1130 * Define a number of .plt lookup outcomes, for use in binding diagnostics. 1131 */ 1132 typedef enum { 1133 PLT_T_NONE = 0, 1134 PLT_T_21D, 1135 PLT_T_24D, 1136 PLT_T_U32, 1137 PLT_T_U44, 1138 PLT_T_FULL, 1139 PLT_T_FAR, 1140 PLT_T_NUM /* Must be last */ 1141 } Pltbindtype; 1142 1143 /* 1144 * Prototypes. 1145 */ 1146 extern ulong_t ld_entry_cnt; /* counter bumped on each entry to */ 1147 /* ld.so.1. */ 1148 extern Lm_list lml_main; /* main's link map list */ 1149 extern Lm_list lml_rtld; /* rtld's link map list */ 1150 extern Lm_list *lml_list[]; 1151 1152 extern Pltbindtype elf_plt_write(uintptr_t, uintptr_t, void *, uintptr_t, 1153 Xword); 1154 extern Rt_map *is_so_loaded(Lm_list *, const char *, int *); 1155 extern int lookup_sym(Slookup *, Sresult *, uint_t *, int *); 1156 extern int rt_dldump(Rt_map *, const char *, int, Addr); 1157 1158 #ifdef __cplusplus 1159 } 1160 #endif 1161 1162 #endif /* _RTLD_H */ 1163