| 1 | /*- |
| 2 | * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. |
| 3 | * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>. |
| 4 | * Copyright 2009, 2010, 2011 Konstantin Belousov <kib@FreeBSD.ORG>. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that the following conditions |
| 9 | * are met: |
| 10 | * 1. Redistributions of source code must retain the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer. |
| 12 | * 2. Redistributions in binary form must reproduce the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer in the |
| 14 | * documentation and/or other materials provided with the distribution. |
| 15 | * |
| 16 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 17 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 18 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 19 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 20 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 21 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 22 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 23 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 24 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 25 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 26 | * |
| 27 | * $FreeBSD: src/libexec/rtld-elf/rtld.c,v 1.173 2011/02/09 09:20:27 kib Exp $ |
| 28 | */ |
| 29 | |
| 30 | /* |
| 31 | * Dynamic linker for ELF. |
| 32 | * |
| 33 | * John Polstra <jdp@polstra.com>. |
| 34 | */ |
| 35 | |
| 36 | #ifndef __GNUC__ |
| 37 | #error "GCC is needed to compile this file" |
| 38 | #endif |
| 39 | |
| 40 | #include <sys/param.h> |
| 41 | #include <sys/mount.h> |
| 42 | #include <sys/mman.h> |
| 43 | #include <sys/stat.h> |
| 44 | #include <sys/uio.h> |
| 45 | #include <sys/utsname.h> |
| 46 | #include <sys/ktrace.h> |
| 47 | #include <sys/resident.h> |
| 48 | #include <sys/tls.h> |
| 49 | |
| 50 | #include <machine/tls.h> |
| 51 | |
| 52 | #include <dlfcn.h> |
| 53 | #include <err.h> |
| 54 | #include <errno.h> |
| 55 | #include <fcntl.h> |
| 56 | #include <stdarg.h> |
| 57 | #include <stdio.h> |
| 58 | #include <stdlib.h> |
| 59 | #include <string.h> |
| 60 | #include <unistd.h> |
| 61 | |
| 62 | #include "debug.h" |
| 63 | #include "rtld.h" |
| 64 | #include "libmap.h" |
| 65 | |
| 66 | #define PATH_RTLD "/usr/libexec/ld-elf.so.2" |
| 67 | #define LD_ARY_CACHE 16 |
| 68 | |
| 69 | /* Types. */ |
| 70 | typedef void (*func_ptr_type)(); |
| 71 | typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg); |
| 72 | |
| 73 | /* |
| 74 | * This structure provides a reentrant way to keep a list of objects and |
| 75 | * check which ones have already been processed in some way. |
| 76 | */ |
| 77 | typedef struct Struct_DoneList { |
| 78 | const Obj_Entry **objs; /* Array of object pointers */ |
| 79 | unsigned int num_alloc; /* Allocated size of the array */ |
| 80 | unsigned int num_used; /* Number of array slots used */ |
| 81 | } DoneList; |
| 82 | |
| 83 | /* |
| 84 | * Function declarations. |
| 85 | */ |
| 86 | static const char *_getenv_ld(const char *id); |
| 87 | static void die(void) __dead2; |
| 88 | static void digest_dynamic(Obj_Entry *, int); |
| 89 | static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); |
| 90 | static Obj_Entry *dlcheck(void *); |
| 91 | static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); |
| 92 | static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); |
| 93 | static bool donelist_check(DoneList *, const Obj_Entry *); |
| 94 | static void errmsg_restore(char *); |
| 95 | static char *errmsg_save(void); |
| 96 | static void *fill_search_info(const char *, size_t, void *); |
| 97 | static char *find_library(const char *, const Obj_Entry *); |
| 98 | static const char *gethints(void); |
| 99 | static void init_dag(Obj_Entry *); |
| 100 | static void init_dag1(Obj_Entry *, Obj_Entry *, DoneList *); |
| 101 | static void init_rtld(caddr_t); |
| 102 | static void initlist_add_neededs(Needed_Entry *, Objlist *); |
| 103 | static void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *); |
| 104 | static bool is_exported(const Elf_Sym *); |
| 105 | static void linkmap_add(Obj_Entry *); |
| 106 | static void linkmap_delete(Obj_Entry *); |
| 107 | static int load_needed_objects(Obj_Entry *, int); |
| 108 | static int load_preload_objects(void); |
| 109 | static Obj_Entry *load_object(const char *, const Obj_Entry *, int); |
| 110 | static Obj_Entry *obj_from_addr(const void *); |
| 111 | static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); |
| 112 | static void objlist_call_init(Objlist *, RtldLockState *); |
| 113 | static void objlist_clear(Objlist *); |
| 114 | static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); |
| 115 | static void objlist_init(Objlist *); |
| 116 | static void objlist_push_head(Objlist *, Obj_Entry *); |
| 117 | static void objlist_push_tail(Objlist *, Obj_Entry *); |
| 118 | static void objlist_remove(Objlist *, Obj_Entry *); |
| 119 | static void *path_enumerate(const char *, path_enum_proc, void *); |
| 120 | static int relocate_objects(Obj_Entry *, bool, Obj_Entry *); |
| 121 | static int rtld_dirname(const char *, char *); |
| 122 | static int rtld_dirname_abs(const char *, char *); |
| 123 | static void rtld_exit(void); |
| 124 | static char *search_library_path(const char *, const char *); |
| 125 | static const void **get_program_var_addr(const char *); |
| 126 | static void set_program_var(const char *, const void *); |
| 127 | static const Elf_Sym *symlook_default(const char *, unsigned long, |
| 128 | const Obj_Entry *, const Obj_Entry **, const Ver_Entry *, int); |
| 129 | static const Elf_Sym *symlook_list(const char *, unsigned long, const Objlist *, |
| 130 | const Obj_Entry **, const Ver_Entry *, int, DoneList *); |
| 131 | static const Elf_Sym *symlook_needed(const char *, unsigned long, |
| 132 | const Needed_Entry *, const Obj_Entry **, const Ver_Entry *, |
| 133 | int, DoneList *); |
| 134 | static void trace_loaded_objects(Obj_Entry *); |
| 135 | static void unlink_object(Obj_Entry *); |
| 136 | static void unload_object(Obj_Entry *); |
| 137 | static void unref_dag(Obj_Entry *); |
| 138 | static void ref_dag(Obj_Entry *); |
| 139 | static int origin_subst_one(char **, const char *, const char *, |
| 140 | const char *, char *); |
| 141 | static char *origin_subst(const char *, const char *); |
| 142 | static int rtld_verify_versions(const Objlist *); |
| 143 | static int rtld_verify_object_versions(Obj_Entry *); |
| 144 | static void object_add_name(Obj_Entry *, const char *); |
| 145 | static int object_match_name(const Obj_Entry *, const char *); |
| 146 | static void ld_utrace_log(int, void *, void *, size_t, int, const char *); |
| 147 | static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, |
| 148 | struct dl_phdr_info *phdr_info); |
| 149 | |
| 150 | void r_debug_state(struct r_debug *, struct link_map *) __noinline; |
| 151 | |
| 152 | /* |
| 153 | * Data declarations. |
| 154 | */ |
| 155 | static char *error_message; /* Message for dlerror(), or NULL */ |
| 156 | struct r_debug r_debug; /* for GDB; */ |
| 157 | static bool libmap_disable; /* Disable libmap */ |
| 158 | static char *libmap_override; /* Maps to use in addition to libmap.conf */ |
| 159 | static bool trust; /* False for setuid and setgid programs */ |
| 160 | static bool dangerous_ld_env; /* True if environment variables have been |
| 161 | used to affect the libraries loaded */ |
| 162 | static const char *ld_bind_now; /* Environment variable for immediate binding */ |
| 163 | static const char *ld_debug; /* Environment variable for debugging */ |
| 164 | static const char *ld_library_path; /* Environment variable for search path */ |
| 165 | static char *ld_preload; /* Environment variable for libraries to |
| 166 | load first */ |
| 167 | static const char *ld_elf_hints_path; /* Environment variable for alternative hints path */ |
| 168 | static const char *ld_tracing; /* Called from ldd(1) to print libs */ |
| 169 | /* Optional function call tracing hook */ |
| 170 | static const char *ld_utrace; /* Use utrace() to log events. */ |
| 171 | static int (*rtld_functrace)(const char *caller_obj, |
| 172 | const char *callee_obj, |
| 173 | const char *callee_func, |
| 174 | void *stack); |
| 175 | static Obj_Entry *rtld_functrace_obj; /* Object thereof */ |
| 176 | static Obj_Entry *obj_list; /* Head of linked list of shared objects */ |
| 177 | static Obj_Entry **obj_tail; /* Link field of last object in list */ |
| 178 | static Obj_Entry **preload_tail; |
| 179 | static Obj_Entry *obj_main; /* The main program shared object */ |
| 180 | static Obj_Entry obj_rtld; /* The dynamic linker shared object */ |
| 181 | static unsigned int obj_count; /* Number of objects in obj_list */ |
| 182 | static unsigned int obj_loads; /* Number of objects in obj_list */ |
| 183 | |
| 184 | static int ld_resident; /* Non-zero if resident */ |
| 185 | static const char *ld_ary[LD_ARY_CACHE]; |
| 186 | static int ld_index; |
| 187 | static Objlist initlist; |
| 188 | |
| 189 | static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ |
| 190 | STAILQ_HEAD_INITIALIZER(list_global); |
| 191 | static Objlist list_main = /* Objects loaded at program startup */ |
| 192 | STAILQ_HEAD_INITIALIZER(list_main); |
| 193 | static Objlist list_fini = /* Objects needing fini() calls */ |
| 194 | STAILQ_HEAD_INITIALIZER(list_fini); |
| 195 | |
| 196 | static Elf_Sym sym_zero; /* For resolving undefined weak refs. */ |
| 197 | |
| 198 | #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); |
| 199 | |
| 200 | extern Elf_Dyn _DYNAMIC; |
| 201 | #pragma weak _DYNAMIC |
| 202 | #ifndef RTLD_IS_DYNAMIC |
| 203 | #define RTLD_IS_DYNAMIC() (&_DYNAMIC != NULL) |
| 204 | #endif |
| 205 | |
| 206 | /* |
| 207 | * These are the functions the dynamic linker exports to application |
| 208 | * programs. They are the only symbols the dynamic linker is willing |
| 209 | * to export from itself. |
| 210 | */ |
| 211 | static func_ptr_type exports[] = { |
| 212 | (func_ptr_type) &_rtld_error, |
| 213 | (func_ptr_type) &dlclose, |
| 214 | (func_ptr_type) &dlerror, |
| 215 | (func_ptr_type) &dlopen, |
| 216 | (func_ptr_type) &dlfunc, |
| 217 | (func_ptr_type) &dlsym, |
| 218 | (func_ptr_type) &dlvsym, |
| 219 | (func_ptr_type) &dladdr, |
| 220 | (func_ptr_type) &dlinfo, |
| 221 | (func_ptr_type) &dl_iterate_phdr, |
| 222 | #ifdef __i386__ |
| 223 | (func_ptr_type) &___tls_get_addr, |
| 224 | #endif |
| 225 | (func_ptr_type) &__tls_get_addr, |
| 226 | (func_ptr_type) &__tls_get_addr_tcb, |
| 227 | (func_ptr_type) &_rtld_allocate_tls, |
| 228 | (func_ptr_type) &_rtld_free_tls, |
| 229 | (func_ptr_type) &_rtld_call_init, |
| 230 | (func_ptr_type) &_rtld_thread_init, |
| 231 | (func_ptr_type) &_rtld_addr_phdr, |
| 232 | NULL |
| 233 | }; |
| 234 | |
| 235 | /* |
| 236 | * Global declarations normally provided by crt1. The dynamic linker is |
| 237 | * not built with crt1, so we have to provide them ourselves. |
| 238 | */ |
| 239 | char *__progname; |
| 240 | char **environ; |
| 241 | |
| 242 | /* |
| 243 | * Globals to control TLS allocation. |
| 244 | */ |
| 245 | size_t tls_last_offset; /* Static TLS offset of last module */ |
| 246 | size_t tls_last_size; /* Static TLS size of last module */ |
| 247 | size_t tls_static_space; /* Static TLS space allocated */ |
| 248 | int tls_dtv_generation = 1; /* Used to detect when dtv size changes */ |
| 249 | int tls_max_index = 1; /* Largest module index allocated */ |
| 250 | |
| 251 | /* |
| 252 | * Fill in a DoneList with an allocation large enough to hold all of |
| 253 | * the currently-loaded objects. Keep this as a macro since it calls |
| 254 | * alloca and we want that to occur within the scope of the caller. |
| 255 | */ |
| 256 | #define donelist_init(dlp) \ |
| 257 | ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ |
| 258 | assert((dlp)->objs != NULL), \ |
| 259 | (dlp)->num_alloc = obj_count, \ |
| 260 | (dlp)->num_used = 0) |
| 261 | |
| 262 | #define UTRACE_DLOPEN_START 1 |
| 263 | #define UTRACE_DLOPEN_STOP 2 |
| 264 | #define UTRACE_DLCLOSE_START 3 |
| 265 | #define UTRACE_DLCLOSE_STOP 4 |
| 266 | #define UTRACE_LOAD_OBJECT 5 |
| 267 | #define UTRACE_UNLOAD_OBJECT 6 |
| 268 | #define UTRACE_ADD_RUNDEP 7 |
| 269 | #define UTRACE_PRELOAD_FINISHED 8 |
| 270 | #define UTRACE_INIT_CALL 9 |
| 271 | #define UTRACE_FINI_CALL 10 |
| 272 | |
| 273 | struct utrace_rtld { |
| 274 | char sig[4]; /* 'RTLD' */ |
| 275 | int event; |
| 276 | void *handle; |
| 277 | void *mapbase; /* Used for 'parent' and 'init/fini' */ |
| 278 | size_t mapsize; |
| 279 | int refcnt; /* Used for 'mode' */ |
| 280 | char name[MAXPATHLEN]; |
| 281 | }; |
| 282 | |
| 283 | #define LD_UTRACE(e, h, mb, ms, r, n) do { \ |
| 284 | if (ld_utrace != NULL) \ |
| 285 | ld_utrace_log(e, h, mb, ms, r, n); \ |
| 286 | } while (0) |
| 287 | |
| 288 | static void |
| 289 | ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, |
| 290 | int refcnt, const char *name) |
| 291 | { |
| 292 | struct utrace_rtld ut; |
| 293 | |
| 294 | ut.sig[0] = 'R'; |
| 295 | ut.sig[1] = 'T'; |
| 296 | ut.sig[2] = 'L'; |
| 297 | ut.sig[3] = 'D'; |
| 298 | ut.event = event; |
| 299 | ut.handle = handle; |
| 300 | ut.mapbase = mapbase; |
| 301 | ut.mapsize = mapsize; |
| 302 | ut.refcnt = refcnt; |
| 303 | bzero(ut.name, sizeof(ut.name)); |
| 304 | if (name) |
| 305 | strlcpy(ut.name, name, sizeof(ut.name)); |
| 306 | utrace(&ut, sizeof(ut)); |
| 307 | } |
| 308 | |
| 309 | /* |
| 310 | * Main entry point for dynamic linking. The first argument is the |
| 311 | * stack pointer. The stack is expected to be laid out as described |
| 312 | * in the SVR4 ABI specification, Intel 386 Processor Supplement. |
| 313 | * Specifically, the stack pointer points to a word containing |
| 314 | * ARGC. Following that in the stack is a null-terminated sequence |
| 315 | * of pointers to argument strings. Then comes a null-terminated |
| 316 | * sequence of pointers to environment strings. Finally, there is a |
| 317 | * sequence of "auxiliary vector" entries. |
| 318 | * |
| 319 | * The second argument points to a place to store the dynamic linker's |
| 320 | * exit procedure pointer and the third to a place to store the main |
| 321 | * program's object. |
| 322 | * |
| 323 | * The return value is the main program's entry point. |
| 324 | */ |
| 325 | func_ptr_type |
| 326 | _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) |
| 327 | { |
| 328 | Elf_Auxinfo *aux_info[AT_COUNT]; |
| 329 | int i; |
| 330 | int argc; |
| 331 | char **argv; |
| 332 | char **env; |
| 333 | Elf_Auxinfo *aux; |
| 334 | Elf_Auxinfo *auxp; |
| 335 | const char *argv0; |
| 336 | Objlist_Entry *entry; |
| 337 | Obj_Entry *obj; |
| 338 | |
| 339 | /* marino: DO NOT MOVE THESE VARIABLES TO _rtld |
| 340 | Obj_Entry **preload_tail; |
| 341 | Objlist initlist; |
| 342 | from global to here. It will break the DRAWF2 unwind scheme. |
| 343 | The system compilers were unaffected, but not gcc 4.6 |
| 344 | */ |
| 345 | |
| 346 | /* |
| 347 | * On entry, the dynamic linker itself has not been relocated yet. |
| 348 | * Be very careful not to reference any global data until after |
| 349 | * init_rtld has returned. It is OK to reference file-scope statics |
| 350 | * and string constants, and to call static and global functions. |
| 351 | */ |
| 352 | |
| 353 | /* Find the auxiliary vector on the stack. */ |
| 354 | argc = *sp++; |
| 355 | argv = (char **) sp; |
| 356 | sp += argc + 1; /* Skip over arguments and NULL terminator */ |
| 357 | env = (char **) sp; |
| 358 | |
| 359 | /* |
| 360 | * If we aren't already resident we have to dig out some more info. |
| 361 | * Note that auxinfo does not exist when we are resident. |
| 362 | * |
| 363 | * I'm not sure about the ld_resident check. It seems to read zero |
| 364 | * prior to relocation, which is what we want. When running from a |
| 365 | * resident copy everything will be relocated so we are definitely |
| 366 | * good there. |
| 367 | */ |
| 368 | if (ld_resident == 0) { |
| 369 | while (*sp++ != 0) /* Skip over environment, and NULL terminator */ |
| 370 | ; |
| 371 | aux = (Elf_Auxinfo *) sp; |
| 372 | |
| 373 | /* Digest the auxiliary vector. */ |
| 374 | for (i = 0; i < AT_COUNT; i++) |
| 375 | aux_info[i] = NULL; |
| 376 | for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { |
| 377 | if (auxp->a_type < AT_COUNT) |
| 378 | aux_info[auxp->a_type] = auxp; |
| 379 | } |
| 380 | |
| 381 | /* Initialize and relocate ourselves. */ |
| 382 | assert(aux_info[AT_BASE] != NULL); |
| 383 | init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr); |
| 384 | } |
| 385 | |
| 386 | ld_index = 0; /* don't use old env cache in case we are resident */ |
| 387 | __progname = obj_rtld.path; |
| 388 | argv0 = argv[0] != NULL ? argv[0] : "(null)"; |
| 389 | environ = env; |
| 390 | |
| 391 | trust = !issetugid(); |
| 392 | |
| 393 | ld_bind_now = _getenv_ld("LD_BIND_NOW"); |
| 394 | /* |
| 395 | * If the process is tainted, then we un-set the dangerous environment |
| 396 | * variables. The process will be marked as tainted until setuid(2) |
| 397 | * is called. If any child process calls setuid(2) we do not want any |
| 398 | * future processes to honor the potentially un-safe variables. |
| 399 | */ |
| 400 | if (!trust) { |
| 401 | if ( unsetenv("LD_DEBUG") |
| 402 | || unsetenv("LD_PRELOAD") |
| 403 | || unsetenv("LD_LIBRARY_PATH") |
| 404 | || unsetenv("LD_ELF_HINTS_PATH") |
| 405 | || unsetenv("LD_LIBMAP") |
| 406 | || unsetenv("LD_LIBMAP_DISABLE") |
| 407 | ) { |
| 408 | _rtld_error("environment corrupt; aborting"); |
| 409 | die(); |
| 410 | } |
| 411 | } |
| 412 | ld_debug = _getenv_ld("LD_DEBUG"); |
| 413 | ld_library_path = _getenv_ld("LD_LIBRARY_PATH"); |
| 414 | ld_preload = (char *)_getenv_ld("LD_PRELOAD"); |
| 415 | ld_elf_hints_path = _getenv_ld("LD_ELF_HINTS_PATH"); |
| 416 | libmap_override = (char *)_getenv_ld("LD_LIBMAP"); |
| 417 | libmap_disable = _getenv_ld("LD_LIBMAP_DISABLE") != NULL; |
| 418 | dangerous_ld_env = (ld_library_path != NULL) |
| 419 | || (ld_preload != NULL) |
| 420 | || (ld_elf_hints_path != NULL) |
| 421 | || (libmap_override != NULL) |
| 422 | || libmap_disable |
| 423 | ; |
| 424 | ld_tracing = _getenv_ld("LD_TRACE_LOADED_OBJECTS"); |
| 425 | ld_utrace = _getenv_ld("LD_UTRACE"); |
| 426 | |
| 427 | if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0) |
| 428 | ld_elf_hints_path = _PATH_ELF_HINTS; |
| 429 | |
| 430 | if (ld_debug != NULL && *ld_debug != '\0') |
| 431 | debug = 1; |
| 432 | dbg("%s is initialized, base address = %p", __progname, |
| 433 | (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); |
| 434 | dbg("RTLD dynamic = %p", obj_rtld.dynamic); |
| 435 | dbg("RTLD pltgot = %p", obj_rtld.pltgot); |
| 436 | |
| 437 | dbg("initializing thread locks"); |
| 438 | lockdflt_init(); |
| 439 | |
| 440 | /* |
| 441 | * If we are resident we can skip work that we have already done. |
| 442 | * Note that the stack is reset and there is no Elf_Auxinfo |
| 443 | * when running from a resident image, and the static globals setup |
| 444 | * between here and resident_skip will have already been setup. |
| 445 | */ |
| 446 | if (ld_resident) |
| 447 | goto resident_skip1; |
| 448 | |
| 449 | /* |
| 450 | * Load the main program, or process its program header if it is |
| 451 | * already loaded. |
| 452 | */ |
| 453 | if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */ |
| 454 | int fd = aux_info[AT_EXECFD]->a_un.a_val; |
| 455 | dbg("loading main program"); |
| 456 | obj_main = map_object(fd, argv0, NULL); |
| 457 | close(fd); |
| 458 | if (obj_main == NULL) |
| 459 | die(); |
| 460 | } else { /* Main program already loaded. */ |
| 461 | const Elf_Phdr *phdr; |
| 462 | int phnum; |
| 463 | caddr_t entry; |
| 464 | |
| 465 | dbg("processing main program's program header"); |
| 466 | assert(aux_info[AT_PHDR] != NULL); |
| 467 | phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; |
| 468 | assert(aux_info[AT_PHNUM] != NULL); |
| 469 | phnum = aux_info[AT_PHNUM]->a_un.a_val; |
| 470 | assert(aux_info[AT_PHENT] != NULL); |
| 471 | assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); |
| 472 | assert(aux_info[AT_ENTRY] != NULL); |
| 473 | entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; |
| 474 | if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL) |
| 475 | die(); |
| 476 | } |
| 477 | |
| 478 | char buf[MAXPATHLEN]; |
| 479 | if (aux_info[AT_EXECPATH] != 0) { |
| 480 | char *kexecpath; |
| 481 | |
| 482 | kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; |
| 483 | dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); |
| 484 | if (kexecpath[0] == '/') |
| 485 | obj_main->path = kexecpath; |
| 486 | else if (getcwd(buf, sizeof(buf)) == NULL || |
| 487 | strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || |
| 488 | strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) |
| 489 | obj_main->path = xstrdup(argv0); |
| 490 | else |
| 491 | obj_main->path = xstrdup(buf); |
| 492 | } else { |
| 493 | char resolved[MAXPATHLEN]; |
| 494 | dbg("No AT_EXECPATH"); |
| 495 | if (argv0[0] == '/') { |
| 496 | if (realpath(argv0, resolved) != NULL) |
| 497 | obj_main->path = xstrdup(resolved); |
| 498 | else |
| 499 | obj_main->path = xstrdup(argv0); |
| 500 | } else { |
| 501 | if (getcwd(buf, sizeof(buf)) != NULL |
| 502 | && strlcat(buf, "/", sizeof(buf)) < sizeof(buf) |
| 503 | && strlcat(buf, argv0, sizeof (buf)) < sizeof(buf) |
| 504 | && access(buf, R_OK) == 0 |
| 505 | && realpath(buf, resolved) != NULL) |
| 506 | obj_main->path = xstrdup(resolved); |
| 507 | else |
| 508 | obj_main->path = xstrdup(argv0); |
| 509 | } |
| 510 | } |
| 511 | dbg("obj_main path %s", obj_main->path); |
| 512 | obj_main->mainprog = true; |
| 513 | |
| 514 | /* |
| 515 | * Get the actual dynamic linker pathname from the executable if |
| 516 | * possible. (It should always be possible.) That ensures that |
| 517 | * gdb will find the right dynamic linker even if a non-standard |
| 518 | * one is being used. |
| 519 | */ |
| 520 | if (obj_main->interp != NULL && |
| 521 | strcmp(obj_main->interp, obj_rtld.path) != 0) { |
| 522 | free(obj_rtld.path); |
| 523 | obj_rtld.path = xstrdup(obj_main->interp); |
| 524 | __progname = obj_rtld.path; |
| 525 | } |
| 526 | |
| 527 | digest_dynamic(obj_main, 0); |
| 528 | |
| 529 | linkmap_add(obj_main); |
| 530 | linkmap_add(&obj_rtld); |
| 531 | |
| 532 | /* Link the main program into the list of objects. */ |
| 533 | *obj_tail = obj_main; |
| 534 | obj_tail = &obj_main->next; |
| 535 | obj_count++; |
| 536 | obj_loads++; |
| 537 | /* Make sure we don't call the main program's init and fini functions. */ |
| 538 | obj_main->init = obj_main->fini = (Elf_Addr)NULL; |
| 539 | |
| 540 | /* Initialize a fake symbol for resolving undefined weak references. */ |
| 541 | sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); |
| 542 | sym_zero.st_shndx = SHN_UNDEF; |
| 543 | sym_zero.st_value = -(uintptr_t)obj_main->relocbase; |
| 544 | |
| 545 | if (!libmap_disable) |
| 546 | libmap_disable = (bool)lm_init(libmap_override); |
| 547 | |
| 548 | dbg("loading LD_PRELOAD libraries"); |
| 549 | if (load_preload_objects() == -1) |
| 550 | die(); |
| 551 | preload_tail = obj_tail; |
| 552 | |
| 553 | dbg("loading needed objects"); |
| 554 | if (load_needed_objects(obj_main, 0) == -1) |
| 555 | die(); |
| 556 | |
| 557 | /* Make a list of all objects loaded at startup. */ |
| 558 | for (obj = obj_list; obj != NULL; obj = obj->next) { |
| 559 | objlist_push_tail(&list_main, obj); |
| 560 | obj->refcount++; |
| 561 | } |
| 562 | |
| 563 | dbg("checking for required versions"); |
| 564 | if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) |
| 565 | die(); |
| 566 | |
| 567 | resident_skip1: |
| 568 | |
| 569 | if (ld_tracing) { /* We're done */ |
| 570 | trace_loaded_objects(obj_main); |
| 571 | exit(0); |
| 572 | } |
| 573 | |
| 574 | if (ld_resident) /* XXX clean this up! */ |
| 575 | goto resident_skip2; |
| 576 | |
| 577 | if (_getenv_ld("LD_DUMP_REL_PRE") != NULL) { |
| 578 | dump_relocations(obj_main); |
| 579 | exit (0); |
| 580 | } |
| 581 | |
| 582 | /* setup TLS for main thread */ |
| 583 | dbg("initializing initial thread local storage"); |
| 584 | STAILQ_FOREACH(entry, &list_main, link) { |
| 585 | /* |
| 586 | * Allocate all the initial objects out of the static TLS |
| 587 | * block even if they didn't ask for it. |
| 588 | */ |
| 589 | allocate_tls_offset(entry->obj); |
| 590 | } |
| 591 | |
| 592 | tls_static_space = tls_last_offset + RTLD_STATIC_TLS_EXTRA; |
| 593 | |
| 594 | /* |
| 595 | * Do not try to allocate the TLS here, let libc do it itself. |
| 596 | * (crt1 for the program will call _init_tls()) |
| 597 | */ |
| 598 | |
| 599 | if (relocate_objects(obj_main, |
| 600 | ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld) == -1) |
| 601 | die(); |
| 602 | |
| 603 | dbg("doing copy relocations"); |
| 604 | if (do_copy_relocations(obj_main) == -1) |
| 605 | die(); |
| 606 | |
| 607 | resident_skip2: |
| 608 | |
| 609 | if (_getenv_ld("LD_RESIDENT_UNREGISTER_NOW")) { |
| 610 | if (exec_sys_unregister(-1) < 0) { |
| 611 | dbg("exec_sys_unregister failed %d\n", errno); |
| 612 | exit(errno); |
| 613 | } |
| 614 | dbg("exec_sys_unregister success\n"); |
| 615 | exit(0); |
| 616 | } |
| 617 | |
| 618 | if (_getenv_ld("LD_DUMP_REL_POST") != NULL) { |
| 619 | dump_relocations(obj_main); |
| 620 | exit (0); |
| 621 | } |
| 622 | |
| 623 | dbg("initializing key program variables"); |
| 624 | set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); |
| 625 | set_program_var("environ", env); |
| 626 | |
| 627 | if (_getenv_ld("LD_RESIDENT_REGISTER_NOW")) { |
| 628 | extern void resident_start(void); |
| 629 | ld_resident = 1; |
| 630 | if (exec_sys_register(resident_start) < 0) { |
| 631 | dbg("exec_sys_register failed %d\n", errno); |
| 632 | exit(errno); |
| 633 | } |
| 634 | dbg("exec_sys_register success\n"); |
| 635 | exit(0); |
| 636 | } |
| 637 | |
| 638 | /* Make a list of init functions to call. */ |
| 639 | objlist_init(&initlist); |
| 640 | initlist_add_objects(obj_list, preload_tail, &initlist); |
| 641 | |
| 642 | r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ |
| 643 | |
| 644 | /* |
| 645 | * Do NOT call the initlist here, give libc a chance to set up |
| 646 | * the initial TLS segment. crt1 will then call _rtld_call_init(). |
| 647 | */ |
| 648 | |
| 649 | dbg("transferring control to program entry point = %p", obj_main->entry); |
| 650 | |
| 651 | /* Return the exit procedure and the program entry point. */ |
| 652 | *exit_proc = rtld_exit; |
| 653 | *objp = obj_main; |
| 654 | return (func_ptr_type) obj_main->entry; |
| 655 | } |
| 656 | |
| 657 | /* |
| 658 | * Call the initialization list for dynamically loaded libraries. |
| 659 | * (called from crt1.c). |
| 660 | */ |
| 661 | void |
| 662 | _rtld_call_init(void) |
| 663 | { |
| 664 | RtldLockState lockstate; |
| 665 | |
| 666 | wlock_acquire(rtld_bind_lock, &lockstate); |
| 667 | objlist_call_init(&initlist, &lockstate); |
| 668 | objlist_clear(&initlist); |
| 669 | lock_release(rtld_bind_lock, &lockstate); |
| 670 | } |
| 671 | |
| 672 | Elf_Addr |
| 673 | _rtld_bind(Obj_Entry *obj, Elf_Size reloff, void *stack) |
| 674 | { |
| 675 | const Elf_Rel *rel; |
| 676 | const Elf_Sym *def; |
| 677 | const Obj_Entry *defobj; |
| 678 | Elf_Addr *where; |
| 679 | Elf_Addr target; |
| 680 | RtldLockState lockstate; |
| 681 | int do_reloc = 1; |
| 682 | |
| 683 | rlock_acquire(rtld_bind_lock, &lockstate); |
| 684 | if (sigsetjmp(lockstate.env, 0) != 0) |
| 685 | lock_upgrade(rtld_bind_lock, &lockstate); |
| 686 | if (obj->pltrel) |
| 687 | rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff); |
| 688 | else |
| 689 | rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff); |
| 690 | |
| 691 | where = (Elf_Addr *) (obj->relocbase + rel->r_offset); |
| 692 | def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL); |
| 693 | if (def == NULL) |
| 694 | die(); |
| 695 | |
| 696 | target = (Elf_Addr)(defobj->relocbase + def->st_value); |
| 697 | |
| 698 | dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", |
| 699 | defobj->strtab + def->st_name, basename(obj->path), |
| 700 | (void *)target, basename(defobj->path)); |
| 701 | |
| 702 | /* |
| 703 | * If we have a function call tracing hook, and the |
| 704 | * hook would like to keep tracing this one function, |
| 705 | * prevent the relocation so we will wind up here |
| 706 | * the next time again. |
| 707 | * |
| 708 | * We don't want to functrace calls from the functracer |
| 709 | * to avoid recursive loops. |
| 710 | */ |
| 711 | if (rtld_functrace != NULL && obj != rtld_functrace_obj) { |
| 712 | if (rtld_functrace(obj->path, |
| 713 | defobj->path, |
| 714 | defobj->strtab + def->st_name, |
| 715 | stack)) |
| 716 | do_reloc = 0; |
| 717 | } |
| 718 | |
| 719 | if (do_reloc) |
| 720 | target = reloc_jmpslot(where, target, defobj, obj, rel); |
| 721 | lock_release(rtld_bind_lock, &lockstate); |
| 722 | return target; |
| 723 | } |
| 724 | |
| 725 | /* |
| 726 | * Error reporting function. Use it like printf. If formats the message |
| 727 | * into a buffer, and sets things up so that the next call to dlerror() |
| 728 | * will return the message. |
| 729 | */ |
| 730 | void |
| 731 | _rtld_error(const char *fmt, ...) |
| 732 | { |
| 733 | static char buf[512]; |
| 734 | va_list ap; |
| 735 | |
| 736 | va_start(ap, fmt); |
| 737 | vsnprintf(buf, sizeof buf, fmt, ap); |
| 738 | error_message = buf; |
| 739 | va_end(ap); |
| 740 | } |
| 741 | |
| 742 | /* |
| 743 | * Return a dynamically-allocated copy of the current error message, if any. |
| 744 | */ |
| 745 | static char * |
| 746 | errmsg_save(void) |
| 747 | { |
| 748 | return error_message == NULL ? NULL : xstrdup(error_message); |
| 749 | } |
| 750 | |
| 751 | /* |
| 752 | * Restore the current error message from a copy which was previously saved |
| 753 | * by errmsg_save(). The copy is freed. |
| 754 | */ |
| 755 | static void |
| 756 | errmsg_restore(char *saved_msg) |
| 757 | { |
| 758 | if (saved_msg == NULL) |
| 759 | error_message = NULL; |
| 760 | else { |
| 761 | _rtld_error("%s", saved_msg); |
| 762 | free(saved_msg); |
| 763 | } |
| 764 | } |
| 765 | |
| 766 | const char * |
| 767 | basename(const char *name) |
| 768 | { |
| 769 | const char *p = strrchr(name, '/'); |
| 770 | return p != NULL ? p + 1 : name; |
| 771 | } |
| 772 | |
| 773 | static struct utsname uts; |
| 774 | |
| 775 | static int |
| 776 | origin_subst_one(char **res, const char *real, const char *kw, const char *subst, |
| 777 | char *may_free) |
| 778 | { |
| 779 | const char *p, *p1; |
| 780 | char *res1; |
| 781 | int subst_len; |
| 782 | int kw_len; |
| 783 | |
| 784 | res1 = *res = NULL; |
| 785 | p = real; |
| 786 | subst_len = kw_len = 0; |
| 787 | for (;;) { |
| 788 | p1 = strstr(p, kw); |
| 789 | if (p1 != NULL) { |
| 790 | if (subst_len == 0) { |
| 791 | subst_len = strlen(subst); |
| 792 | kw_len = strlen(kw); |
| 793 | } |
| 794 | if (*res == NULL) { |
| 795 | *res = xmalloc(PATH_MAX); |
| 796 | res1 = *res; |
| 797 | } |
| 798 | if ((res1 - *res) + subst_len + (p1 - p) >= PATH_MAX) { |
| 799 | _rtld_error("Substitution of %s in %s cannot be performed", |
| 800 | kw, real); |
| 801 | if (may_free != NULL) |
| 802 | free(may_free); |
| 803 | free(res); |
| 804 | return (false); |
| 805 | } |
| 806 | memcpy(res1, p, p1 - p); |
| 807 | res1 += p1 - p; |
| 808 | memcpy(res1, subst, subst_len); |
| 809 | res1 += subst_len; |
| 810 | p = p1 + kw_len; |
| 811 | } else { |
| 812 | if (*res == NULL) { |
| 813 | if (may_free != NULL) |
| 814 | *res = may_free; |
| 815 | else |
| 816 | *res = xstrdup(real); |
| 817 | return (true); |
| 818 | } |
| 819 | *res1 = '\0'; |
| 820 | if (may_free != NULL) |
| 821 | free(may_free); |
| 822 | if (strlcat(res1, p, PATH_MAX - (res1 - *res)) >= PATH_MAX) { |
| 823 | free(res); |
| 824 | return (false); |
| 825 | } |
| 826 | return (true); |
| 827 | } |
| 828 | } |
| 829 | } |
| 830 | |
| 831 | static char * |
| 832 | origin_subst(const char *real, const char *origin_path) |
| 833 | { |
| 834 | char *res1, *res2, *res3, *res4; |
| 835 | |
| 836 | if (uts.sysname[0] == '\0') { |
| 837 | if (uname(&uts) != 0) { |
| 838 | _rtld_error("utsname failed: %d", errno); |
| 839 | return (NULL); |
| 840 | } |
| 841 | } |
| 842 | if (!origin_subst_one(&res1, real, "$ORIGIN", origin_path, NULL) || |
| 843 | !origin_subst_one(&res2, res1, "$OSNAME", uts.sysname, res1) || |
| 844 | !origin_subst_one(&res3, res2, "$OSREL", uts.release, res2) || |
| 845 | !origin_subst_one(&res4, res3, "$PLATFORM", uts.machine, res3)) |
| 846 | return (NULL); |
| 847 | return (res4); |
| 848 | } |
| 849 | |
| 850 | static void |
| 851 | die(void) |
| 852 | { |
| 853 | const char *msg = dlerror(); |
| 854 | |
| 855 | if (msg == NULL) |
| 856 | msg = "Fatal error"; |
| 857 | errx(1, "%s", msg); |
| 858 | } |
| 859 | |
| 860 | /* |
| 861 | * Process a shared object's DYNAMIC section, and save the important |
| 862 | * information in its Obj_Entry structure. |
| 863 | */ |
| 864 | static void |
| 865 | digest_dynamic(Obj_Entry *obj, int early) |
| 866 | { |
| 867 | const Elf_Dyn *dynp; |
| 868 | Needed_Entry **needed_tail = &obj->needed; |
| 869 | const Elf_Dyn *dyn_rpath = NULL; |
| 870 | const Elf_Dyn *dyn_soname = NULL; |
| 871 | int plttype = DT_REL; |
| 872 | |
| 873 | obj->bind_now = false; |
| 874 | for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) { |
| 875 | switch (dynp->d_tag) { |
| 876 | |
| 877 | case DT_REL: |
| 878 | obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr); |
| 879 | break; |
| 880 | |
| 881 | case DT_RELSZ: |
| 882 | obj->relsize = dynp->d_un.d_val; |
| 883 | break; |
| 884 | |
| 885 | case DT_RELENT: |
| 886 | assert(dynp->d_un.d_val == sizeof(Elf_Rel)); |
| 887 | break; |
| 888 | |
| 889 | case DT_JMPREL: |
| 890 | obj->pltrel = (const Elf_Rel *) |
| 891 | (obj->relocbase + dynp->d_un.d_ptr); |
| 892 | break; |
| 893 | |
| 894 | case DT_PLTRELSZ: |
| 895 | obj->pltrelsize = dynp->d_un.d_val; |
| 896 | break; |
| 897 | |
| 898 | case DT_RELA: |
| 899 | obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr); |
| 900 | break; |
| 901 | |
| 902 | case DT_RELASZ: |
| 903 | obj->relasize = dynp->d_un.d_val; |
| 904 | break; |
| 905 | |
| 906 | case DT_RELAENT: |
| 907 | assert(dynp->d_un.d_val == sizeof(Elf_Rela)); |
| 908 | break; |
| 909 | |
| 910 | case DT_PLTREL: |
| 911 | plttype = dynp->d_un.d_val; |
| 912 | assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); |
| 913 | break; |
| 914 | |
| 915 | case DT_SYMTAB: |
| 916 | obj->symtab = (const Elf_Sym *) |
| 917 | (obj->relocbase + dynp->d_un.d_ptr); |
| 918 | break; |
| 919 | |
| 920 | case DT_SYMENT: |
| 921 | assert(dynp->d_un.d_val == sizeof(Elf_Sym)); |
| 922 | break; |
| 923 | |
| 924 | case DT_STRTAB: |
| 925 | obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr); |
| 926 | break; |
| 927 | |
| 928 | case DT_STRSZ: |
| 929 | obj->strsize = dynp->d_un.d_val; |
| 930 | break; |
| 931 | |
| 932 | case DT_VERNEED: |
| 933 | obj->verneed = (const Elf_Verneed *) (obj->relocbase + |
| 934 | dynp->d_un.d_val); |
| 935 | break; |
| 936 | |
| 937 | case DT_VERNEEDNUM: |
| 938 | obj->verneednum = dynp->d_un.d_val; |
| 939 | break; |
| 940 | |
| 941 | case DT_VERDEF: |
| 942 | obj->verdef = (const Elf_Verdef *) (obj->relocbase + |
| 943 | dynp->d_un.d_val); |
| 944 | break; |
| 945 | |
| 946 | case DT_VERDEFNUM: |
| 947 | obj->verdefnum = dynp->d_un.d_val; |
| 948 | break; |
| 949 | |
| 950 | case DT_VERSYM: |
| 951 | obj->versyms = (const Elf_Versym *)(obj->relocbase + |
| 952 | dynp->d_un.d_val); |
| 953 | break; |
| 954 | |
| 955 | case DT_HASH: |
| 956 | { |
| 957 | const Elf_Hashelt *hashtab = (const Elf_Hashelt *) |
| 958 | (obj->relocbase + dynp->d_un.d_ptr); |
| 959 | obj->nbuckets = hashtab[0]; |
| 960 | obj->nchains = hashtab[1]; |
| 961 | obj->buckets = hashtab + 2; |
| 962 | obj->chains = obj->buckets + obj->nbuckets; |
| 963 | } |
| 964 | break; |
| 965 | |
| 966 | case DT_NEEDED: |
| 967 | if (!obj->rtld) { |
| 968 | Needed_Entry *nep = NEW(Needed_Entry); |
| 969 | nep->name = dynp->d_un.d_val; |
| 970 | nep->obj = NULL; |
| 971 | nep->next = NULL; |
| 972 | |
| 973 | *needed_tail = nep; |
| 974 | needed_tail = &nep->next; |
| 975 | } |
| 976 | break; |
| 977 | |
| 978 | case DT_PLTGOT: |
| 979 | obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr); |
| 980 | break; |
| 981 | |
| 982 | case DT_TEXTREL: |
| 983 | obj->textrel = true; |
| 984 | break; |
| 985 | |
| 986 | case DT_SYMBOLIC: |
| 987 | obj->symbolic = true; |
| 988 | break; |
| 989 | |
| 990 | case DT_RPATH: |
| 991 | case DT_RUNPATH: /* XXX: process separately */ |
| 992 | /* |
| 993 | * We have to wait until later to process this, because we |
| 994 | * might not have gotten the address of the string table yet. |
| 995 | */ |
| 996 | dyn_rpath = dynp; |
| 997 | break; |
| 998 | |
| 999 | case DT_SONAME: |
| 1000 | dyn_soname = dynp; |
| 1001 | break; |
| 1002 | |
| 1003 | case DT_INIT: |
| 1004 | obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); |
| 1005 | break; |
| 1006 | |
| 1007 | case DT_FINI: |
| 1008 | obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); |
| 1009 | break; |
| 1010 | |
| 1011 | case DT_DEBUG: |
| 1012 | /* XXX - not implemented yet */ |
| 1013 | if (!early) |
| 1014 | dbg("Filling in DT_DEBUG entry"); |
| 1015 | ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug; |
| 1016 | break; |
| 1017 | |
| 1018 | case DT_FLAGS: |
| 1019 | if ((dynp->d_un.d_val & DF_ORIGIN) && trust) |
| 1020 | obj->z_origin = true; |
| 1021 | if (dynp->d_un.d_val & DF_SYMBOLIC) |
| 1022 | obj->symbolic = true; |
| 1023 | if (dynp->d_un.d_val & DF_TEXTREL) |
| 1024 | obj->textrel = true; |
| 1025 | if (dynp->d_un.d_val & DF_BIND_NOW) |
| 1026 | obj->bind_now = true; |
| 1027 | /*if (dynp->d_un.d_val & DF_STATIC_TLS) |
| 1028 | ;*/ |
| 1029 | break; |
| 1030 | |
| 1031 | case DT_FLAGS_1: |
| 1032 | if (dynp->d_un.d_val & DF_1_NOOPEN) |
| 1033 | obj->z_noopen = true; |
| 1034 | if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust) |
| 1035 | obj->z_origin = true; |
| 1036 | /*if (dynp->d_un.d_val & DF_1_GLOBAL) |
| 1037 | XXX ;*/ |
| 1038 | if (dynp->d_un.d_val & DF_1_BIND_NOW) |
| 1039 | obj->bind_now = true; |
| 1040 | if (dynp->d_un.d_val & DF_1_NODELETE) |
| 1041 | obj->z_nodelete = true; |
| 1042 | break; |
| 1043 | |
| 1044 | default: |
| 1045 | if (!early) { |
| 1046 | dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, |
| 1047 | (long)dynp->d_tag); |
| 1048 | } |
| 1049 | break; |
| 1050 | } |
| 1051 | } |
| 1052 | |
| 1053 | obj->traced = false; |
| 1054 | |
| 1055 | if (plttype == DT_RELA) { |
| 1056 | obj->pltrela = (const Elf_Rela *) obj->pltrel; |
| 1057 | obj->pltrel = NULL; |
| 1058 | obj->pltrelasize = obj->pltrelsize; |
| 1059 | obj->pltrelsize = 0; |
| 1060 | } |
| 1061 | |
| 1062 | if (obj->z_origin && obj->origin_path == NULL) { |
| 1063 | obj->origin_path = xmalloc(PATH_MAX); |
| 1064 | if (rtld_dirname_abs(obj->path, obj->origin_path) == -1) |
| 1065 | die(); |
| 1066 | } |
| 1067 | |
| 1068 | if (dyn_rpath != NULL) { |
| 1069 | obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val; |
| 1070 | if (obj->z_origin) |
| 1071 | obj->rpath = origin_subst(obj->rpath, obj->origin_path); |
| 1072 | } |
| 1073 | |
| 1074 | if (dyn_soname != NULL) |
| 1075 | object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); |
| 1076 | } |
| 1077 | |
| 1078 | /* |
| 1079 | * Process a shared object's program header. This is used only for the |
| 1080 | * main program, when the kernel has already loaded the main program |
| 1081 | * into memory before calling the dynamic linker. It creates and |
| 1082 | * returns an Obj_Entry structure. |
| 1083 | */ |
| 1084 | static Obj_Entry * |
| 1085 | digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) |
| 1086 | { |
| 1087 | Obj_Entry *obj; |
| 1088 | const Elf_Phdr *phlimit = phdr + phnum; |
| 1089 | const Elf_Phdr *ph; |
| 1090 | int nsegs = 0; |
| 1091 | |
| 1092 | obj = obj_new(); |
| 1093 | for (ph = phdr; ph < phlimit; ph++) { |
| 1094 | if (ph->p_type != PT_PHDR) |
| 1095 | continue; |
| 1096 | |
| 1097 | obj->phdr = phdr; |
| 1098 | obj->phsize = ph->p_memsz; |
| 1099 | obj->relocbase = (caddr_t)phdr - ph->p_vaddr; |
| 1100 | break; |
| 1101 | } |
| 1102 | |
| 1103 | for (ph = phdr; ph < phlimit; ph++) { |
| 1104 | switch (ph->p_type) { |
| 1105 | |
| 1106 | case PT_INTERP: |
| 1107 | obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); |
| 1108 | break; |
| 1109 | |
| 1110 | case PT_LOAD: |
| 1111 | if (nsegs == 0) { /* First load segment */ |
| 1112 | obj->vaddrbase = trunc_page(ph->p_vaddr); |
| 1113 | obj->mapbase = obj->vaddrbase + obj->relocbase; |
| 1114 | obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) - |
| 1115 | obj->vaddrbase; |
| 1116 | } else { /* Last load segment */ |
| 1117 | obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - |
| 1118 | obj->vaddrbase; |
| 1119 | } |
| 1120 | nsegs++; |
| 1121 | break; |
| 1122 | |
| 1123 | case PT_DYNAMIC: |
| 1124 | obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); |
| 1125 | break; |
| 1126 | |
| 1127 | case PT_TLS: |
| 1128 | obj->tlsindex = 1; |
| 1129 | obj->tlssize = ph->p_memsz; |
| 1130 | obj->tlsalign = ph->p_align; |
| 1131 | obj->tlsinitsize = ph->p_filesz; |
| 1132 | obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); |
| 1133 | break; |
| 1134 | |
| 1135 | case PT_GNU_RELRO: |
| 1136 | obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); |
| 1137 | obj->relro_size = round_page(ph->p_memsz); |
| 1138 | break; |
| 1139 | } |
| 1140 | } |
| 1141 | if (nsegs < 1) { |
| 1142 | _rtld_error("%s: too few PT_LOAD segments", path); |
| 1143 | return NULL; |
| 1144 | } |
| 1145 | |
| 1146 | obj->entry = entry; |
| 1147 | return obj; |
| 1148 | } |
| 1149 | |
| 1150 | static Obj_Entry * |
| 1151 | dlcheck(void *handle) |
| 1152 | { |
| 1153 | Obj_Entry *obj; |
| 1154 | |
| 1155 | for (obj = obj_list; obj != NULL; obj = obj->next) |
| 1156 | if (obj == (Obj_Entry *) handle) |
| 1157 | break; |
| 1158 | |
| 1159 | if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { |
| 1160 | _rtld_error("Invalid shared object handle %p", handle); |
| 1161 | return NULL; |
| 1162 | } |
| 1163 | return obj; |
| 1164 | } |
| 1165 | |
| 1166 | /* |
| 1167 | * If the given object is already in the donelist, return true. Otherwise |
| 1168 | * add the object to the list and return false. |
| 1169 | */ |
| 1170 | static bool |
| 1171 | donelist_check(DoneList *dlp, const Obj_Entry *obj) |
| 1172 | { |
| 1173 | unsigned int i; |
| 1174 | |
| 1175 | for (i = 0; i < dlp->num_used; i++) |
| 1176 | if (dlp->objs[i] == obj) |
| 1177 | return true; |
| 1178 | /* |
| 1179 | * Our donelist allocation should always be sufficient. But if |
| 1180 | * our threads locking isn't working properly, more shared objects |
| 1181 | * could have been loaded since we allocated the list. That should |
| 1182 | * never happen, but we'll handle it properly just in case it does. |
| 1183 | */ |
| 1184 | if (dlp->num_used < dlp->num_alloc) |
| 1185 | dlp->objs[dlp->num_used++] = obj; |
| 1186 | return false; |
| 1187 | } |
| 1188 | |
| 1189 | /* |
| 1190 | * Hash function for symbol table lookup. Don't even think about changing |
| 1191 | * this. It is specified by the System V ABI. |
| 1192 | */ |
| 1193 | unsigned long |
| 1194 | elf_hash(const char *name) |
| 1195 | { |
| 1196 | const unsigned char *p = (const unsigned char *) name; |
| 1197 | unsigned long h = 0; |
| 1198 | unsigned long g; |
| 1199 | |
| 1200 | while (*p != '\0') { |
| 1201 | h = (h << 4) + *p++; |
| 1202 | if ((g = h & 0xf0000000) != 0) |
| 1203 | h ^= g >> 24; |
| 1204 | h &= ~g; |
| 1205 | } |
| 1206 | return h; |
| 1207 | } |
| 1208 | |
| 1209 | /* |
| 1210 | * Find the library with the given name, and return its full pathname. |
| 1211 | * The returned string is dynamically allocated. Generates an error |
| 1212 | * message and returns NULL if the library cannot be found. |
| 1213 | * |
| 1214 | * If the second argument is non-NULL, then it refers to an already- |
| 1215 | * loaded shared object, whose library search path will be searched. |
| 1216 | * |
| 1217 | * The search order is: |
| 1218 | * LD_LIBRARY_PATH |
| 1219 | * rpath in the referencing file |
| 1220 | * ldconfig hints |
| 1221 | * /usr/lib |
| 1222 | */ |
| 1223 | static char * |
| 1224 | find_library(const char *xname, const Obj_Entry *refobj) |
| 1225 | { |
| 1226 | char *pathname; |
| 1227 | char *name; |
| 1228 | |
| 1229 | if (strchr(xname, '/') != NULL) { /* Hard coded pathname */ |
| 1230 | if (xname[0] != '/' && !trust) { |
| 1231 | _rtld_error("Absolute pathname required for shared object \"%s\"", |
| 1232 | xname); |
| 1233 | return NULL; |
| 1234 | } |
| 1235 | if (refobj != NULL && refobj->z_origin) |
| 1236 | return origin_subst(xname, refobj->origin_path); |
| 1237 | else |
| 1238 | return xstrdup(xname); |
| 1239 | } |
| 1240 | |
| 1241 | if (libmap_disable || (refobj == NULL) || |
| 1242 | (name = lm_find(refobj->path, xname)) == NULL) |
| 1243 | name = (char *)xname; |
| 1244 | |
| 1245 | dbg(" Searching for \"%s\"", name); |
| 1246 | |
| 1247 | if ((pathname = search_library_path(name, ld_library_path)) != NULL || |
| 1248 | (refobj != NULL && |
| 1249 | (pathname = search_library_path(name, refobj->rpath)) != NULL) || |
| 1250 | (pathname = search_library_path(name, gethints())) != NULL || |
| 1251 | (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL) |
| 1252 | return pathname; |
| 1253 | |
| 1254 | if(refobj != NULL && refobj->path != NULL) { |
| 1255 | _rtld_error("Shared object \"%s\" not found, required by \"%s\"", |
| 1256 | name, basename(refobj->path)); |
| 1257 | } else { |
| 1258 | _rtld_error("Shared object \"%s\" not found", name); |
| 1259 | } |
| 1260 | return NULL; |
| 1261 | } |
| 1262 | |
| 1263 | /* |
| 1264 | * Given a symbol number in a referencing object, find the corresponding |
| 1265 | * definition of the symbol. Returns a pointer to the symbol, or NULL if |
| 1266 | * no definition was found. Returns a pointer to the Obj_Entry of the |
| 1267 | * defining object via the reference parameter DEFOBJ_OUT. |
| 1268 | */ |
| 1269 | const Elf_Sym * |
| 1270 | find_symdef(unsigned long symnum, const Obj_Entry *refobj, |
| 1271 | const Obj_Entry **defobj_out, int flags, SymCache *cache) |
| 1272 | { |
| 1273 | const Elf_Sym *ref; |
| 1274 | const Elf_Sym *def; |
| 1275 | const Obj_Entry *defobj; |
| 1276 | const Ver_Entry *ventry; |
| 1277 | const char *name; |
| 1278 | unsigned long hash; |
| 1279 | |
| 1280 | /* |
| 1281 | * If we have already found this symbol, get the information from |
| 1282 | * the cache. |
| 1283 | */ |
| 1284 | if (symnum >= refobj->nchains) |
| 1285 | return NULL; /* Bad object */ |
| 1286 | if (cache != NULL && cache[symnum].sym != NULL) { |
| 1287 | *defobj_out = cache[symnum].obj; |
| 1288 | return cache[symnum].sym; |
| 1289 | } |
| 1290 | |
| 1291 | ref = refobj->symtab + symnum; |
| 1292 | name = refobj->strtab + ref->st_name; |
| 1293 | defobj = NULL; |
| 1294 | |
| 1295 | /* |
| 1296 | * We don't have to do a full scale lookup if the symbol is local. |
| 1297 | * We know it will bind to the instance in this load module; to |
| 1298 | * which we already have a pointer (ie ref). By not doing a lookup, |
| 1299 | * we not only improve performance, but it also avoids unresolvable |
| 1300 | * symbols when local symbols are not in the hash table. |
| 1301 | * |
| 1302 | * This might occur for TLS module relocations, which simply use |
| 1303 | * symbol 0. |
| 1304 | */ |
| 1305 | if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { |
| 1306 | if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { |
| 1307 | _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, |
| 1308 | symnum); |
| 1309 | } |
| 1310 | ventry = fetch_ventry(refobj, symnum); |
| 1311 | hash = elf_hash(name); |
| 1312 | def = symlook_default(name, hash, refobj, &defobj, ventry, flags); |
| 1313 | } else { |
| 1314 | def = ref; |
| 1315 | defobj = refobj; |
| 1316 | } |
| 1317 | |
| 1318 | /* |
| 1319 | * If we found no definition and the reference is weak, treat the |
| 1320 | * symbol as having the value zero. |
| 1321 | */ |
| 1322 | if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { |
| 1323 | def = &sym_zero; |
| 1324 | defobj = obj_main; |
| 1325 | } |
| 1326 | |
| 1327 | if (def != NULL) { |
| 1328 | *defobj_out = defobj; |
| 1329 | /* Record the information in the cache to avoid subsequent lookups. */ |
| 1330 | if (cache != NULL) { |
| 1331 | cache[symnum].sym = def; |
| 1332 | cache[symnum].obj = defobj; |
| 1333 | } |
| 1334 | } else { |
| 1335 | if (refobj != &obj_rtld) |
| 1336 | _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name); |
| 1337 | } |
| 1338 | return def; |
| 1339 | } |
| 1340 | |
| 1341 | /* |
| 1342 | * Return the search path from the ldconfig hints file, reading it if |
| 1343 | * necessary. Returns NULL if there are problems with the hints file, |
| 1344 | * or if the search path there is empty. |
| 1345 | */ |
| 1346 | static const char * |
| 1347 | gethints(void) |
| 1348 | { |
| 1349 | static char *hints; |
| 1350 | |
| 1351 | if (hints == NULL) { |
| 1352 | int fd; |
| 1353 | struct elfhints_hdr hdr; |
| 1354 | char *p; |
| 1355 | |
| 1356 | /* Keep from trying again in case the hints file is bad. */ |
| 1357 | hints = ""; |
| 1358 | |
| 1359 | if ((fd = open(ld_elf_hints_path, O_RDONLY)) == -1) |
| 1360 | return NULL; |
| 1361 | if (read(fd, &hdr, sizeof hdr) != sizeof hdr || |
| 1362 | hdr.magic != ELFHINTS_MAGIC || |
| 1363 | hdr.version != 1) { |
| 1364 | close(fd); |
| 1365 | return NULL; |
| 1366 | } |
| 1367 | p = xmalloc(hdr.dirlistlen + 1); |
| 1368 | if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 || |
| 1369 | read(fd, p, hdr.dirlistlen + 1) != (ssize_t)hdr.dirlistlen + 1) { |
| 1370 | free(p); |
| 1371 | close(fd); |
| 1372 | return NULL; |
| 1373 | } |
| 1374 | hints = p; |
| 1375 | close(fd); |
| 1376 | } |
| 1377 | return hints[0] != '\0' ? hints : NULL; |
| 1378 | } |
| 1379 | |
| 1380 | static void |
| 1381 | init_dag(Obj_Entry *root) |
| 1382 | { |
| 1383 | DoneList donelist; |
| 1384 | |
| 1385 | if (root->dag_inited) |
| 1386 | return; |
| 1387 | donelist_init(&donelist); |
| 1388 | init_dag1(root, root, &donelist); |
| 1389 | } |
| 1390 | |
| 1391 | static void |
| 1392 | init_dag1(Obj_Entry *root, Obj_Entry *obj, DoneList *dlp) |
| 1393 | { |
| 1394 | const Needed_Entry *needed; |
| 1395 | |
| 1396 | if (donelist_check(dlp, obj)) |
| 1397 | return; |
| 1398 | |
| 1399 | objlist_push_tail(&obj->dldags, root); |
| 1400 | objlist_push_tail(&root->dagmembers, obj); |
| 1401 | for (needed = obj->needed; needed != NULL; needed = needed->next) |
| 1402 | if (needed->obj != NULL) |
| 1403 | init_dag1(root, needed->obj, dlp); |
| 1404 | root->dag_inited = true; |
| 1405 | } |
| 1406 | |
| 1407 | /* |
| 1408 | * Initialize the dynamic linker. The argument is the address at which |
| 1409 | * the dynamic linker has been mapped into memory. The primary task of |
| 1410 | * this function is to relocate the dynamic linker. |
| 1411 | */ |
| 1412 | static void |
| 1413 | init_rtld(caddr_t mapbase) |
| 1414 | { |
| 1415 | Obj_Entry objtmp; /* Temporary rtld object */ |
| 1416 | |
| 1417 | /* |
| 1418 | * Conjure up an Obj_Entry structure for the dynamic linker. |
| 1419 | * |
| 1420 | * The "path" member can't be initialized yet because string constants |
| 1421 | * cannot yet be accessed. Below we will set it correctly. |
| 1422 | */ |
| 1423 | memset(&objtmp, 0, sizeof(objtmp)); |
| 1424 | objtmp.path = NULL; |
| 1425 | objtmp.rtld = true; |
| 1426 | objtmp.mapbase = mapbase; |
| 1427 | #ifdef PIC |
| 1428 | objtmp.relocbase = mapbase; |
| 1429 | #endif |
| 1430 | if (RTLD_IS_DYNAMIC()) { |
| 1431 | objtmp.dynamic = rtld_dynamic(&objtmp); |
| 1432 | digest_dynamic(&objtmp, 1); |
| 1433 | assert(objtmp.needed == NULL); |
| 1434 | assert(!objtmp.textrel); |
| 1435 | |
| 1436 | /* |
| 1437 | * Temporarily put the dynamic linker entry into the object list, so |
| 1438 | * that symbols can be found. |
| 1439 | */ |
| 1440 | |
| 1441 | relocate_objects(&objtmp, true, &objtmp); |
| 1442 | } |
| 1443 | |
| 1444 | /* Initialize the object list. */ |
| 1445 | obj_tail = &obj_list; |
| 1446 | |
| 1447 | /* Now that non-local variables can be accesses, copy out obj_rtld. */ |
| 1448 | memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); |
| 1449 | |
| 1450 | /* Replace the path with a dynamically allocated copy. */ |
| 1451 | obj_rtld.path = xstrdup(PATH_RTLD); |
| 1452 | |
| 1453 | r_debug.r_brk = r_debug_state; |
| 1454 | r_debug.r_state = RT_CONSISTENT; |
| 1455 | } |
| 1456 | |
| 1457 | /* |
| 1458 | * Add the init functions from a needed object list (and its recursive |
| 1459 | * needed objects) to "list". This is not used directly; it is a helper |
| 1460 | * function for initlist_add_objects(). The write lock must be held |
| 1461 | * when this function is called. |
| 1462 | */ |
| 1463 | static void |
| 1464 | initlist_add_neededs(Needed_Entry *needed, Objlist *list) |
| 1465 | { |
| 1466 | /* Recursively process the successor needed objects. */ |
| 1467 | if (needed->next != NULL) |
| 1468 | initlist_add_neededs(needed->next, list); |
| 1469 | |
| 1470 | /* Process the current needed object. */ |
| 1471 | if (needed->obj != NULL) |
| 1472 | initlist_add_objects(needed->obj, &needed->obj->next, list); |
| 1473 | } |
| 1474 | |
| 1475 | /* |
| 1476 | * Scan all of the DAGs rooted in the range of objects from "obj" to |
| 1477 | * "tail" and add their init functions to "list". This recurses over |
| 1478 | * the DAGs and ensure the proper init ordering such that each object's |
| 1479 | * needed libraries are initialized before the object itself. At the |
| 1480 | * same time, this function adds the objects to the global finalization |
| 1481 | * list "list_fini" in the opposite order. The write lock must be |
| 1482 | * held when this function is called. |
| 1483 | */ |
| 1484 | static void |
| 1485 | initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list) |
| 1486 | { |
| 1487 | if (obj->init_scanned || obj->init_done) |
| 1488 | return; |
| 1489 | obj->init_scanned = true; |
| 1490 | |
| 1491 | /* Recursively process the successor objects. */ |
| 1492 | if (&obj->next != tail) |
| 1493 | initlist_add_objects(obj->next, tail, list); |
| 1494 | |
| 1495 | /* Recursively process the needed objects. */ |
| 1496 | if (obj->needed != NULL) |
| 1497 | initlist_add_neededs(obj->needed, list); |
| 1498 | |
| 1499 | /* Add the object to the init list. */ |
| 1500 | if (obj->init != (Elf_Addr)NULL) |
| 1501 | objlist_push_tail(list, obj); |
| 1502 | |
| 1503 | /* Add the object to the global fini list in the reverse order. */ |
| 1504 | if (obj->fini != (Elf_Addr)NULL && !obj->on_fini_list) { |
| 1505 | objlist_push_head(&list_fini, obj); |
| 1506 | obj->on_fini_list = true; |
| 1507 | } |
| 1508 | } |
| 1509 | |
| 1510 | #ifndef FPTR_TARGET |
| 1511 | #define FPTR_TARGET(f) ((Elf_Addr) (f)) |
| 1512 | #endif |
| 1513 | |
| 1514 | static bool |
| 1515 | is_exported(const Elf_Sym *def) |
| 1516 | { |
| 1517 | Elf_Addr value; |
| 1518 | const func_ptr_type *p; |
| 1519 | |
| 1520 | value = (Elf_Addr)(obj_rtld.relocbase + def->st_value); |
| 1521 | for (p = exports; *p != NULL; p++) |
| 1522 | if (FPTR_TARGET(*p) == value) |
| 1523 | return true; |
| 1524 | return false; |
| 1525 | } |
| 1526 | |
| 1527 | /* |
| 1528 | * Given a shared object, traverse its list of needed objects, and load |
| 1529 | * each of them. Returns 0 on success. Generates an error message and |
| 1530 | * returns -1 on failure. |
| 1531 | */ |
| 1532 | static int |
| 1533 | load_needed_objects(Obj_Entry *first, int flags) |
| 1534 | { |
| 1535 | Obj_Entry *obj, *obj1; |
| 1536 | |
| 1537 | for (obj = first; obj != NULL; obj = obj->next) { |
| 1538 | Needed_Entry *needed; |
| 1539 | |
| 1540 | for (needed = obj->needed; needed != NULL; needed = needed->next) { |
| 1541 | obj1 = needed->obj = load_object(obj->strtab + needed->name, obj, |
| 1542 | flags & ~RTLD_LO_NOLOAD); |
| 1543 | if (obj1 == NULL && !ld_tracing) |
| 1544 | return -1; |
| 1545 | if (obj1 != NULL && obj1->z_nodelete && !obj1->ref_nodel) { |
| 1546 | dbg("obj %s nodelete", obj1->path); |
| 1547 | init_dag(obj1); |
| 1548 | ref_dag(obj1); |
| 1549 | obj1->ref_nodel = true; |
| 1550 | } |
| 1551 | } |
| 1552 | } |
| 1553 | return (0); |
| 1554 | } |
| 1555 | |
| 1556 | #define RTLD_FUNCTRACE "_rtld_functrace" |
| 1557 | |
| 1558 | static int |
| 1559 | load_preload_objects(void) |
| 1560 | { |
| 1561 | char *p = ld_preload; |
| 1562 | static const char delim[] = " \t:;"; |
| 1563 | |
| 1564 | if (p == NULL) |
| 1565 | return 0; |
| 1566 | |
| 1567 | p += strspn(p, delim); |
| 1568 | while (*p != '\0') { |
| 1569 | size_t len = strcspn(p, delim); |
| 1570 | char savech; |
| 1571 | Obj_Entry *obj; |
| 1572 | const Elf_Sym *sym; |
| 1573 | |
| 1574 | savech = p[len]; |
| 1575 | p[len] = '\0'; |
| 1576 | obj = load_object(p, NULL, 0); |
| 1577 | if (obj == NULL) |
| 1578 | return -1; /* XXX - cleanup */ |
| 1579 | p[len] = savech; |
| 1580 | p += len; |
| 1581 | p += strspn(p, delim); |
| 1582 | |
| 1583 | /* Check for the magic tracing function */ |
| 1584 | sym = symlook_obj(RTLD_FUNCTRACE, elf_hash(RTLD_FUNCTRACE), obj, NULL, 1); |
| 1585 | if (sym != NULL) { |
| 1586 | rtld_functrace = (void *)(obj->relocbase + sym->st_value); |
| 1587 | rtld_functrace_obj = obj; |
| 1588 | } |
| 1589 | } |
| 1590 | LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); |
| 1591 | return 0; |
| 1592 | } |
| 1593 | |
| 1594 | /* |
| 1595 | * Load a shared object into memory, if it is not already loaded. |
| 1596 | * |
| 1597 | * Returns a pointer to the Obj_Entry for the object. Returns NULL |
| 1598 | * on failure. |
| 1599 | */ |
| 1600 | static Obj_Entry * |
| 1601 | load_object(const char *name, const Obj_Entry *refobj, int flags) |
| 1602 | { |
| 1603 | Obj_Entry *obj; |
| 1604 | int fd = -1; |
| 1605 | struct stat sb; |
| 1606 | char *path; |
| 1607 | |
| 1608 | for (obj = obj_list->next; obj != NULL; obj = obj->next) |
| 1609 | if (object_match_name(obj, name)) |
| 1610 | return obj; |
| 1611 | |
| 1612 | path = find_library(name, refobj); |
| 1613 | if (path == NULL) |
| 1614 | return NULL; |
| 1615 | |
| 1616 | /* |
| 1617 | * If we didn't find a match by pathname, open the file and check |
| 1618 | * again by device and inode. This avoids false mismatches caused |
| 1619 | * by multiple links or ".." in pathnames. |
| 1620 | * |
| 1621 | * To avoid a race, we open the file and use fstat() rather than |
| 1622 | * using stat(). |
| 1623 | */ |
| 1624 | if ((fd = open(path, O_RDONLY)) == -1) { |
| 1625 | _rtld_error("Cannot open \"%s\"", path); |
| 1626 | free(path); |
| 1627 | return NULL; |
| 1628 | } |
| 1629 | if (fstat(fd, &sb) == -1) { |
| 1630 | _rtld_error("Cannot fstat \"%s\"", path); |
| 1631 | close(fd); |
| 1632 | free(path); |
| 1633 | return NULL; |
| 1634 | } |
| 1635 | for (obj = obj_list->next; obj != NULL; obj = obj->next) |
| 1636 | if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) |
| 1637 | break; |
| 1638 | if (obj != NULL) { |
| 1639 | object_add_name(obj, name); |
| 1640 | free(path); |
| 1641 | close(fd); |
| 1642 | return obj; |
| 1643 | } |
| 1644 | if (flags & RTLD_LO_NOLOAD) { |
| 1645 | free(path); |
| 1646 | close(fd); |
| 1647 | return (NULL); |
| 1648 | } |
| 1649 | |
| 1650 | /* First use of this object, so we must map it in */ |
| 1651 | obj = do_load_object(fd, name, path, &sb, flags); |
| 1652 | if (obj == NULL) |
| 1653 | free(path); |
| 1654 | close(fd); |
| 1655 | |
| 1656 | return obj; |
| 1657 | } |
| 1658 | |
| 1659 | static Obj_Entry * |
| 1660 | do_load_object(int fd, const char *name, char *path, struct stat *sbp, |
| 1661 | int flags) |
| 1662 | { |
| 1663 | Obj_Entry *obj; |
| 1664 | struct statfs fs; |
| 1665 | |
| 1666 | /* |
| 1667 | * but first, make sure that environment variables haven't been |
| 1668 | * used to circumvent the noexec flag on a filesystem. |
| 1669 | */ |
| 1670 | if (dangerous_ld_env) { |
| 1671 | if (fstatfs(fd, &fs) != 0) { |
| 1672 | _rtld_error("Cannot fstatfs \"%s\"", path); |
| 1673 | return NULL; |
| 1674 | } |
| 1675 | if (fs.f_flags & MNT_NOEXEC) { |
| 1676 | _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname); |
| 1677 | return NULL; |
| 1678 | } |
| 1679 | } |
| 1680 | dbg("loading \"%s\"", path); |
| 1681 | obj = map_object(fd, path, sbp); |
| 1682 | if (obj == NULL) |
| 1683 | return NULL; |
| 1684 | |
| 1685 | object_add_name(obj, name); |
| 1686 | obj->path = path; |
| 1687 | digest_dynamic(obj, 0); |
| 1688 | if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == |
| 1689 | RTLD_LO_DLOPEN) { |
| 1690 | dbg("refusing to load non-loadable \"%s\"", obj->path); |
| 1691 | _rtld_error("Cannot dlopen non-loadable %s", obj->path); |
| 1692 | munmap(obj->mapbase, obj->mapsize); |
| 1693 | obj_free(obj); |
| 1694 | return (NULL); |
| 1695 | } |
| 1696 | |
| 1697 | *obj_tail = obj; |
| 1698 | obj_tail = &obj->next; |
| 1699 | obj_count++; |
| 1700 | obj_loads++; |
| 1701 | linkmap_add(obj); /* for GDB & dlinfo() */ |
| 1702 | |
| 1703 | dbg(" %p .. %p: %s", obj->mapbase, |
| 1704 | obj->mapbase + obj->mapsize - 1, obj->path); |
| 1705 | if (obj->textrel) |
| 1706 | dbg(" WARNING: %s has impure text", obj->path); |
| 1707 | LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, |
| 1708 | obj->path); |
| 1709 | |
| 1710 | return obj; |
| 1711 | } |
| 1712 | |
| 1713 | static Obj_Entry * |
| 1714 | obj_from_addr(const void *addr) |
| 1715 | { |
| 1716 | Obj_Entry *obj; |
| 1717 | |
| 1718 | for (obj = obj_list; obj != NULL; obj = obj->next) { |
| 1719 | if (addr < (void *) obj->mapbase) |
| 1720 | continue; |
| 1721 | if (addr < (void *) (obj->mapbase + obj->mapsize)) |
| 1722 | return obj; |
| 1723 | } |
| 1724 | return NULL; |
| 1725 | } |
| 1726 | |
| 1727 | /* |
| 1728 | * Call the finalization functions for each of the objects in "list" |
| 1729 | * belonging to the DAG of "root" and referenced once. If NULL "root" |
| 1730 | * is specified, every finalization function will be called regardless |
| 1731 | * of the reference count and the list elements won't be freed. All of |
| 1732 | * the objects are expected to have non-NULL fini functions. |
| 1733 | */ |
| 1734 | static void |
| 1735 | objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) |
| 1736 | { |
| 1737 | Objlist_Entry *elm; |
| 1738 | char *saved_msg; |
| 1739 | |
| 1740 | assert(root == NULL || root->refcount == 1); |
| 1741 | |
| 1742 | /* |
| 1743 | * Preserve the current error message since a fini function might |
| 1744 | * call into the dynamic linker and overwrite it. |
| 1745 | */ |
| 1746 | saved_msg = errmsg_save(); |
| 1747 | do { |
| 1748 | STAILQ_FOREACH(elm, list, link) { |
| 1749 | if (root != NULL && (elm->obj->refcount != 1 || |
| 1750 | objlist_find(&root->dagmembers, elm->obj) == NULL)) |
| 1751 | continue; |
| 1752 | dbg("calling fini function for %s at %p", elm->obj->path, |
| 1753 | (void *)elm->obj->fini); |
| 1754 | LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 0, 0, |
| 1755 | elm->obj->path); |
| 1756 | /* Remove object from fini list to prevent recursive invocation. */ |
| 1757 | STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); |
| 1758 | /* |
| 1759 | * XXX: If a dlopen() call references an object while the |
| 1760 | * fini function is in progress, we might end up trying to |
| 1761 | * unload the referenced object in dlclose() or the object |
| 1762 | * won't be unloaded although its fini function has been |
| 1763 | * called. |
| 1764 | */ |
| 1765 | lock_release(rtld_bind_lock, lockstate); |
| 1766 | call_initfini_pointer(elm->obj, elm->obj->fini); |
| 1767 | wlock_acquire(rtld_bind_lock, lockstate); |
| 1768 | /* No need to free anything if process is going down. */ |
| 1769 | if (root != NULL) |
| 1770 | free(elm); |
| 1771 | /* |
| 1772 | * We must restart the list traversal after every fini call |
| 1773 | * because a dlclose() call from the fini function or from |
| 1774 | * another thread might have modified the reference counts. |
| 1775 | */ |
| 1776 | break; |
| 1777 | } |
| 1778 | } while (elm != NULL); |
| 1779 | errmsg_restore(saved_msg); |
| 1780 | } |
| 1781 | |
| 1782 | /* |
| 1783 | * Call the initialization functions for each of the objects in |
| 1784 | * "list". All of the objects are expected to have non-NULL init |
| 1785 | * functions. |
| 1786 | */ |
| 1787 | static void |
| 1788 | objlist_call_init(Objlist *list, RtldLockState *lockstate) |
| 1789 | { |
| 1790 | Objlist_Entry *elm; |
| 1791 | Obj_Entry *obj; |
| 1792 | char *saved_msg; |
| 1793 | |
| 1794 | /* |
| 1795 | * Clean init_scanned flag so that objects can be rechecked and |
| 1796 | * possibly initialized earlier if any of vectors called below |
| 1797 | * cause the change by using dlopen. |
| 1798 | */ |
| 1799 | for (obj = obj_list; obj != NULL; obj = obj->next) |
| 1800 | obj->init_scanned = false; |
| 1801 | |
| 1802 | /* |
| 1803 | * Preserve the current error message since an init function might |
| 1804 | * call into the dynamic linker and overwrite it. |
| 1805 | */ |
| 1806 | saved_msg = errmsg_save(); |
| 1807 | STAILQ_FOREACH(elm, list, link) { |
| 1808 | if (elm->obj->init_done) /* Initialized early. */ |
| 1809 | continue; |
| 1810 | dbg("calling init function for %s at %p", elm->obj->path, |
| 1811 | (void *)elm->obj->init); |
| 1812 | LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 0, 0, |
| 1813 | elm->obj->path); |
| 1814 | /* |
| 1815 | * Race: other thread might try to use this object before current |
| 1816 | * one completes the initilization. Not much can be done here |
| 1817 | * without better locking. |
| 1818 | */ |
| 1819 | elm->obj->init_done = true; |
| 1820 | lock_release(rtld_bind_lock, lockstate); |
| 1821 | call_initfini_pointer(elm->obj, elm->obj->init); |
| 1822 | wlock_acquire(rtld_bind_lock, lockstate); |
| 1823 | } |
| 1824 | errmsg_restore(saved_msg); |
| 1825 | } |
| 1826 | |
| 1827 | static void |
| 1828 | objlist_clear(Objlist *list) |
| 1829 | { |
| 1830 | Objlist_Entry *elm; |
| 1831 | |
| 1832 | while (!STAILQ_EMPTY(list)) { |
| 1833 | elm = STAILQ_FIRST(list); |
| 1834 | STAILQ_REMOVE_HEAD(list, link); |
| 1835 | free(elm); |
| 1836 | } |
| 1837 | } |
| 1838 | |
| 1839 | static Objlist_Entry * |
| 1840 | objlist_find(Objlist *list, const Obj_Entry *obj) |
| 1841 | { |
| 1842 | Objlist_Entry *elm; |
| 1843 | |
| 1844 | STAILQ_FOREACH(elm, list, link) |
| 1845 | if (elm->obj == obj) |
| 1846 | return elm; |
| 1847 | return NULL; |
| 1848 | } |
| 1849 | |
| 1850 | static void |
| 1851 | objlist_init(Objlist *list) |
| 1852 | { |
| 1853 | STAILQ_INIT(list); |
| 1854 | } |
| 1855 | |
| 1856 | static void |
| 1857 | objlist_push_head(Objlist *list, Obj_Entry *obj) |
| 1858 | { |
| 1859 | Objlist_Entry *elm; |
| 1860 | |
| 1861 | elm = NEW(Objlist_Entry); |
| 1862 | elm->obj = obj; |
| 1863 | STAILQ_INSERT_HEAD(list, elm, link); |
| 1864 | } |
| 1865 | |
| 1866 | static void |
| 1867 | objlist_push_tail(Objlist *list, Obj_Entry *obj) |
| 1868 | { |
| 1869 | Objlist_Entry *elm; |
| 1870 | |
| 1871 | elm = NEW(Objlist_Entry); |
| 1872 | elm->obj = obj; |
| 1873 | STAILQ_INSERT_TAIL(list, elm, link); |
| 1874 | } |
| 1875 | |
| 1876 | static void |
| 1877 | objlist_remove(Objlist *list, Obj_Entry *obj) |
| 1878 | { |
| 1879 | Objlist_Entry *elm; |
| 1880 | |
| 1881 | if ((elm = objlist_find(list, obj)) != NULL) { |
| 1882 | STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); |
| 1883 | free(elm); |
| 1884 | } |
| 1885 | } |
| 1886 | |
| 1887 | /* |
| 1888 | * Relocate newly-loaded shared objects. The argument is a pointer to |
| 1889 | * the Obj_Entry for the first such object. All objects from the first |
| 1890 | * to the end of the list of objects are relocated. Returns 0 on success, |
| 1891 | * or -1 on failure. |
| 1892 | */ |
| 1893 | static int |
| 1894 | relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj) |
| 1895 | { |
| 1896 | Obj_Entry *obj; |
| 1897 | |
| 1898 | for (obj = first; obj != NULL; obj = obj->next) { |
| 1899 | if (obj != rtldobj) |
| 1900 | dbg("relocating \"%s\"", obj->path); |
| 1901 | if (obj->nbuckets == 0 || obj->nchains == 0 || obj->buckets == NULL || |
| 1902 | obj->symtab == NULL || obj->strtab == NULL) { |
| 1903 | _rtld_error("%s: Shared object has no run-time symbol table", |
| 1904 | obj->path); |
| 1905 | return -1; |
| 1906 | } |
| 1907 | |
| 1908 | if (obj->textrel) { |
| 1909 | /* There are relocations to the write-protected text segment. */ |
| 1910 | if (mprotect(obj->mapbase, obj->textsize, |
| 1911 | PROT_READ|PROT_WRITE|PROT_EXEC) == -1) { |
| 1912 | _rtld_error("%s: Cannot write-enable text segment: %s", |
| 1913 | obj->path, strerror(errno)); |
| 1914 | return -1; |
| 1915 | } |
| 1916 | } |
| 1917 | |
| 1918 | /* Process the non-PLT relocations. */ |
| 1919 | if (reloc_non_plt(obj, rtldobj)) |
| 1920 | return -1; |
| 1921 | |
| 1922 | /* |
| 1923 | * Reprotect the text segment. Make sure it is included in the |
| 1924 | * core dump since we modified it. This unfortunately causes the |
| 1925 | * entire text segment to core-out but we don't have much of a |
| 1926 | * choice. We could try to only reenable core dumps on pages |
| 1927 | * in which relocations occured but that is likely most of the text |
| 1928 | * pages anyway, and even that would not work because the rest of |
| 1929 | * the text pages would wind up as a read-only OBJT_DEFAULT object |
| 1930 | * (created due to our modifications) backed by the original OBJT_VNODE |
| 1931 | * object, and the ELF coredump code is currently only able to dump |
| 1932 | * vnode records for pure vnode-backed mappings, not vnode backings |
| 1933 | * to memory objects. |
| 1934 | */ |
| 1935 | if (obj->textrel) { |
| 1936 | madvise(obj->mapbase, obj->textsize, MADV_CORE); |
| 1937 | if (mprotect(obj->mapbase, obj->textsize, |
| 1938 | PROT_READ|PROT_EXEC) == -1) { |
| 1939 | _rtld_error("%s: Cannot write-protect text segment: %s", |
| 1940 | obj->path, strerror(errno)); |
| 1941 | return -1; |
| 1942 | } |
| 1943 | } |
| 1944 | |
| 1945 | /* Process the PLT relocations. */ |
| 1946 | if (reloc_plt(obj) == -1) |
| 1947 | return -1; |
| 1948 | /* Relocate the jump slots if we are doing immediate binding. */ |
| 1949 | if (obj->bind_now || bind_now) |
| 1950 | if (reloc_jmpslots(obj) == -1) |
| 1951 | return -1; |
| 1952 | |
| 1953 | /* Set the special PLT or GOT entries. */ |
| 1954 | init_pltgot(obj); |
| 1955 | |
| 1956 | /* |
| 1957 | * Set up the magic number and version in the Obj_Entry. These |
| 1958 | * were checked in the crt1.o from the original ElfKit, so we |
| 1959 | * set them for backward compatibility. |
| 1960 | */ |
| 1961 | obj->magic = RTLD_MAGIC; |
| 1962 | obj->version = RTLD_VERSION; |
| 1963 | |
| 1964 | /* |
| 1965 | * Set relocated data to read-only status if protection specified |
| 1966 | */ |
| 1967 | |
| 1968 | if (obj->relro_size) { |
| 1969 | if (mprotect(obj->relro_page, obj->relro_size, PROT_READ) == -1) { |
| 1970 | _rtld_error("%s: Cannot enforce relro relocation: %s", |
| 1971 | obj->path, strerror(errno)); |
| 1972 | return -1; |
| 1973 | } |
| 1974 | } |
| 1975 | } |
| 1976 | |
| 1977 | return (0); |
| 1978 | } |
| 1979 | |
| 1980 | /* |
| 1981 | * Cleanup procedure. It will be called (by the atexit mechanism) just |
| 1982 | * before the process exits. |
| 1983 | */ |
| 1984 | static void |
| 1985 | rtld_exit(void) |
| 1986 | { |
| 1987 | RtldLockState lockstate; |
| 1988 | |
| 1989 | wlock_acquire(rtld_bind_lock, &lockstate); |
| 1990 | dbg("rtld_exit()"); |
| 1991 | objlist_call_fini(&list_fini, NULL, &lockstate); |
| 1992 | /* No need to remove the items from the list, since we are exiting. */ |
| 1993 | if (!libmap_disable) |
| 1994 | lm_fini(); |
| 1995 | lock_release(rtld_bind_lock, &lockstate); |
| 1996 | } |
| 1997 | |
| 1998 | static void * |
| 1999 | path_enumerate(const char *path, path_enum_proc callback, void *arg) |
| 2000 | { |
| 2001 | if (path == NULL) |
| 2002 | return (NULL); |
| 2003 | |
| 2004 | path += strspn(path, ":;"); |
| 2005 | while (*path != '\0') { |
| 2006 | size_t len; |
| 2007 | char *res; |
| 2008 | |
| 2009 | len = strcspn(path, ":;"); |
| 2010 | res = callback(path, len, arg); |
| 2011 | |
| 2012 | if (res != NULL) |
| 2013 | return (res); |
| 2014 | |
| 2015 | path += len; |
| 2016 | path += strspn(path, ":;"); |
| 2017 | } |
| 2018 | |
| 2019 | return (NULL); |
| 2020 | } |
| 2021 | |
| 2022 | struct try_library_args { |
| 2023 | const char *name; |
| 2024 | size_t namelen; |
| 2025 | char *buffer; |
| 2026 | size_t buflen; |
| 2027 | }; |
| 2028 | |
| 2029 | static void * |
| 2030 | try_library_path(const char *dir, size_t dirlen, void *param) |
| 2031 | { |
| 2032 | struct try_library_args *arg; |
| 2033 | |
| 2034 | arg = param; |
| 2035 | if (*dir == '/' || trust) { |
| 2036 | char *pathname; |
| 2037 | |
| 2038 | if (dirlen + 1 + arg->namelen + 1 > arg->buflen) |
| 2039 | return (NULL); |
| 2040 | |
| 2041 | pathname = arg->buffer; |
| 2042 | strncpy(pathname, dir, dirlen); |
| 2043 | pathname[dirlen] = '/'; |
| 2044 | strcpy(pathname + dirlen + 1, arg->name); |
| 2045 | |
| 2046 | dbg(" Trying \"%s\"", pathname); |
| 2047 | if (access(pathname, F_OK) == 0) { /* We found it */ |
| 2048 | pathname = xmalloc(dirlen + 1 + arg->namelen + 1); |
| 2049 | strcpy(pathname, arg->buffer); |
| 2050 | return (pathname); |
| 2051 | } |
| 2052 | } |
| 2053 | return (NULL); |
| 2054 | } |
| 2055 | |
| 2056 | static char * |
| 2057 | search_library_path(const char *name, const char *path) |
| 2058 | { |
| 2059 | char *p; |
| 2060 | struct try_library_args arg; |
| 2061 | |
| 2062 | if (path == NULL) |
| 2063 | return NULL; |
| 2064 | |
| 2065 | arg.name = name; |
| 2066 | arg.namelen = strlen(name); |
| 2067 | arg.buffer = xmalloc(PATH_MAX); |
| 2068 | arg.buflen = PATH_MAX; |
| 2069 | |
| 2070 | p = path_enumerate(path, try_library_path, &arg); |
| 2071 | |
| 2072 | free(arg.buffer); |
| 2073 | |
| 2074 | return (p); |
| 2075 | } |
| 2076 | |
| 2077 | int |
| 2078 | dlclose(void *handle) |
| 2079 | { |
| 2080 | Obj_Entry *root; |
| 2081 | RtldLockState lockstate; |
| 2082 | |
| 2083 | wlock_acquire(rtld_bind_lock, &lockstate); |
| 2084 | root = dlcheck(handle); |
| 2085 | if (root == NULL) { |
| 2086 | lock_release(rtld_bind_lock, &lockstate); |
| 2087 | return -1; |
| 2088 | } |
| 2089 | LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, |
| 2090 | root->path); |
| 2091 | |
| 2092 | /* Unreference the object and its dependencies. */ |
| 2093 | root->dl_refcount--; |
| 2094 | |
| 2095 | if (root->refcount == 1) { |
| 2096 | /* |
| 2097 | * The object will be no longer referenced, so we must unload it. |
| 2098 | * First, call the fini functions. |
| 2099 | */ |
| 2100 | objlist_call_fini(&list_fini, root, &lockstate); |
| 2101 | |
| 2102 | unref_dag(root); |
| 2103 | |
| 2104 | /* Finish cleaning up the newly-unreferenced objects. */ |
| 2105 | GDB_STATE(RT_DELETE,&root->linkmap); |
| 2106 | unload_object(root); |
| 2107 | GDB_STATE(RT_CONSISTENT,NULL); |
| 2108 | } else |
| 2109 | unref_dag(root); |
| 2110 | |
| 2111 | LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); |
| 2112 | lock_release(rtld_bind_lock, &lockstate); |
| 2113 | return 0; |
| 2114 | } |
| 2115 | |
| 2116 | char * |
| 2117 | dlerror(void) |
| 2118 | { |
| 2119 | char *msg = error_message; |
| 2120 | error_message = NULL; |
| 2121 | return msg; |
| 2122 | } |
| 2123 | |
| 2124 | void * |
| 2125 | dlopen(const char *name, int mode) |
| 2126 | { |
| 2127 | Obj_Entry **old_obj_tail; |
| 2128 | Obj_Entry *obj; |
| 2129 | Objlist initlist; |
| 2130 | RtldLockState lockstate; |
| 2131 | int result, lo_flags; |
| 2132 | |
| 2133 | LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); |
| 2134 | ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; |
| 2135 | if (ld_tracing != NULL) |
| 2136 | environ = (char **)*get_program_var_addr("environ"); |
| 2137 | lo_flags = RTLD_LO_DLOPEN; |
| 2138 | if (mode & RTLD_NODELETE) |
| 2139 | lo_flags |= RTLD_LO_NODELETE; |
| 2140 | if (mode & RTLD_NOLOAD) |
| 2141 | lo_flags |= RTLD_LO_NOLOAD; |
| 2142 | if (ld_tracing != NULL) |
| 2143 | lo_flags |= RTLD_LO_TRACE; |
| 2144 | |
| 2145 | objlist_init(&initlist); |
| 2146 | |
| 2147 | wlock_acquire(rtld_bind_lock, &lockstate); |
| 2148 | GDB_STATE(RT_ADD,NULL); |
| 2149 | |
| 2150 | old_obj_tail = obj_tail; |
| 2151 | obj = NULL; |
| 2152 | if (name == NULL) { |
| 2153 | obj = obj_main; |
| 2154 | obj->refcount++; |
| 2155 | } else { |
| 2156 | obj = load_object(name, obj_main, lo_flags); |
| 2157 | } |
| 2158 | |
| 2159 | if (obj) { |
| 2160 | obj->dl_refcount++; |
| 2161 | if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) |
| 2162 | objlist_push_tail(&list_global, obj); |
| 2163 | mode &= RTLD_MODEMASK; |
| 2164 | if (*old_obj_tail != NULL) { /* We loaded something new. */ |
| 2165 | assert(*old_obj_tail == obj); |
| 2166 | result = load_needed_objects(obj, RTLD_LO_DLOPEN); |
| 2167 | init_dag(obj); |
| 2168 | ref_dag(obj); |
| 2169 | if (result != -1) |
| 2170 | result = rtld_verify_versions(&obj->dagmembers); |
| 2171 | if (result != -1 && ld_tracing) |
| 2172 | goto trace; |
| 2173 | if (result == -1 || |
| 2174 | (relocate_objects(obj, mode == RTLD_NOW, &obj_rtld)) == -1) { |
| 2175 | obj->dl_refcount--; |
| 2176 | unref_dag(obj); |
| 2177 | if (obj->refcount == 0) |
| 2178 | unload_object(obj); |
| 2179 | obj = NULL; |
| 2180 | } else { |
| 2181 | /* Make list of init functions to call. */ |
| 2182 | initlist_add_objects(obj, &obj->next, &initlist); |
| 2183 | } |
| 2184 | } else { |
| 2185 | |
| 2186 | /* |
| 2187 | * Bump the reference counts for objects on this DAG. If |
| 2188 | * this is the first dlopen() call for the object that was |
| 2189 | * already loaded as a dependency, initialize the dag |
| 2190 | * starting at it. |
| 2191 | */ |
| 2192 | init_dag(obj); |
| 2193 | ref_dag(obj); |
| 2194 | |
| 2195 | if ((lo_flags & RTLD_LO_TRACE) != 0) |
| 2196 | goto trace; |
| 2197 | } |
| 2198 | if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || |
| 2199 | obj->z_nodelete) && !obj->ref_nodel) { |
| 2200 | dbg("obj %s nodelete", obj->path); |
| 2201 | ref_dag(obj); |
| 2202 | obj->z_nodelete = obj->ref_nodel = true; |
| 2203 | } |
| 2204 | } |
| 2205 | |
| 2206 | LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, |
| 2207 | name); |
| 2208 | GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); |
| 2209 | |
| 2210 | /* Call the init functions. */ |
| 2211 | objlist_call_init(&initlist, &lockstate); |
| 2212 | objlist_clear(&initlist); |
| 2213 | lock_release(rtld_bind_lock, &lockstate); |
| 2214 | return obj; |
| 2215 | trace: |
| 2216 | trace_loaded_objects(obj); |
| 2217 | lock_release(rtld_bind_lock, &lockstate); |
| 2218 | exit(0); |
| 2219 | } |
| 2220 | |
| 2221 | static void * |
| 2222 | do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, |
| 2223 | int flags) |
| 2224 | { |
| 2225 | DoneList donelist; |
| 2226 | const Obj_Entry *obj, *defobj; |
| 2227 | const Elf_Sym *def, *symp; |
| 2228 | unsigned long hash; |
| 2229 | RtldLockState lockstate; |
| 2230 | |
| 2231 | hash = elf_hash(name); |
| 2232 | def = NULL; |
| 2233 | defobj = NULL; |
| 2234 | flags |= SYMLOOK_IN_PLT; |
| 2235 | |
| 2236 | rlock_acquire(rtld_bind_lock, &lockstate); |
| 2237 | if (sigsetjmp(lockstate.env, 0) != 0) |
| 2238 | lock_upgrade(rtld_bind_lock, &lockstate); |
| 2239 | if (handle == NULL || handle == RTLD_NEXT || |
| 2240 | handle == RTLD_DEFAULT || handle == RTLD_SELF) { |
| 2241 | |
| 2242 | if ((obj = obj_from_addr(retaddr)) == NULL) { |
| 2243 | _rtld_error("Cannot determine caller's shared object"); |
| 2244 | lock_release(rtld_bind_lock, &lockstate); |
| 2245 | return NULL; |
| 2246 | } |
| 2247 | if (handle == NULL) { /* Just the caller's shared object. */ |
| 2248 | def = symlook_obj(name, hash, obj, ve, flags); |
| 2249 | defobj = obj; |
| 2250 | } else if (handle == RTLD_NEXT || /* Objects after caller's */ |
| 2251 | handle == RTLD_SELF) { /* ... caller included */ |
| 2252 | if (handle == RTLD_NEXT) |
| 2253 | obj = obj->next; |
| 2254 | for (; obj != NULL; obj = obj->next) { |
| 2255 | if ((symp = symlook_obj(name, hash, obj, ve, flags)) != NULL) { |
| 2256 | if (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK) { |
| 2257 | def = symp; |
| 2258 | defobj = obj; |
| 2259 | if (ELF_ST_BIND(def->st_info) != STB_WEAK) |
| 2260 | break; |
| 2261 | } |
| 2262 | } |
| 2263 | } |
| 2264 | /* |
| 2265 | * Search the dynamic linker itself, and possibly resolve the |
| 2266 | * symbol from there. This is how the application links to |
| 2267 | * dynamic linker services such as dlopen. |
| 2268 | */ |
| 2269 | if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { |
| 2270 | symp = symlook_obj(name, hash, &obj_rtld, ve, flags); |
| 2271 | if (symp != NULL) { |
| 2272 | def = symp; |
| 2273 | defobj = &obj_rtld; |
| 2274 | } |
| 2275 | } |
| 2276 | } else { |
| 2277 | assert(handle == RTLD_DEFAULT); |
| 2278 | def = symlook_default(name, hash, obj, &defobj, ve, flags); |
| 2279 | } |
| 2280 | } else { |
| 2281 | if ((obj = dlcheck(handle)) == NULL) { |
| 2282 | lock_release(rtld_bind_lock, &lockstate); |
| 2283 | return NULL; |
| 2284 | } |
| 2285 | |
| 2286 | donelist_init(&donelist); |
| 2287 | if (obj->mainprog) { |
| 2288 | /* Search main program and all libraries loaded by it. */ |
| 2289 | def = symlook_list(name, hash, &list_main, &defobj, ve, flags, |
| 2290 | &donelist); |
| 2291 | |
| 2292 | /* |
| 2293 | * We do not distinguish between 'main' object and global scope. |
| 2294 | * If symbol is not defined by objects loaded at startup, continue |
| 2295 | * search among dynamically loaded objects with RTLD_GLOBAL |
| 2296 | * scope. |
| 2297 | */ |
| 2298 | if (def == NULL) |
| 2299 | def = symlook_list(name, hash, &list_global, &defobj, ve, |
| 2300 | flags, &donelist); |
| 2301 | } else { |
| 2302 | Needed_Entry fake; |
| 2303 | |
| 2304 | /* Search the whole DAG rooted at the given object. */ |
| 2305 | fake.next = NULL; |
| 2306 | fake.obj = (Obj_Entry *)obj; |
| 2307 | fake.name = 0; |
| 2308 | def = symlook_needed(name, hash, &fake, &defobj, ve, flags, |
| 2309 | &donelist); |
| 2310 | } |
| 2311 | } |
| 2312 | |
| 2313 | if (def != NULL) { |
| 2314 | lock_release(rtld_bind_lock, &lockstate); |
| 2315 | |
| 2316 | /* |
| 2317 | * The value required by the caller is derived from the value |
| 2318 | * of the symbol. For the ia64 architecture, we need to |
| 2319 | * construct a function descriptor which the caller can use to |
| 2320 | * call the function with the right 'gp' value. For other |
| 2321 | * architectures and for non-functions, the value is simply |
| 2322 | * the relocated value of the symbol. |
| 2323 | */ |
| 2324 | if (ELF_ST_TYPE(def->st_info) == STT_FUNC) |
| 2325 | return (make_function_pointer(def, defobj)); |
| 2326 | else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { |
| 2327 | tls_index ti; |
| 2328 | ti.ti_module = defobj->tlsindex; |
| 2329 | ti.ti_offset = def->st_value; |
| 2330 | return (__tls_get_addr(&ti)); |
| 2331 | } else |
| 2332 | return (defobj->relocbase + def->st_value); |
| 2333 | } |
| 2334 | |
| 2335 | _rtld_error("Undefined symbol \"%s\"", name); |
| 2336 | lock_release(rtld_bind_lock, &lockstate); |
| 2337 | return NULL; |
| 2338 | } |
| 2339 | |
| 2340 | void * |
| 2341 | dlsym(void *handle, const char *name) |
| 2342 | { |
| 2343 | return do_dlsym(handle, name, __builtin_return_address(0), NULL, |
| 2344 | SYMLOOK_DLSYM); |
| 2345 | } |
| 2346 | |
| 2347 | dlfunc_t |
| 2348 | dlfunc(void *handle, const char *name) |
| 2349 | { |
| 2350 | union { |
| 2351 | void *d; |
| 2352 | dlfunc_t f; |
| 2353 | } rv; |
| 2354 | |
| 2355 | rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, |
| 2356 | SYMLOOK_DLSYM); |
| 2357 | return (rv.f); |
| 2358 | } |
| 2359 | |
| 2360 | void * |
| 2361 | dlvsym(void *handle, const char *name, const char *version) |
| 2362 | { |
| 2363 | Ver_Entry ventry; |
| 2364 | |
| 2365 | ventry.name = version; |
| 2366 | ventry.file = NULL; |
| 2367 | ventry.hash = elf_hash(version); |
| 2368 | ventry.flags= 0; |
| 2369 | return do_dlsym(handle, name, __builtin_return_address(0), &ventry, |
| 2370 | SYMLOOK_DLSYM); |
| 2371 | } |
| 2372 | |
| 2373 | int |
| 2374 | _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) |
| 2375 | { |
| 2376 | const Obj_Entry *obj; |
| 2377 | RtldLockState lockstate; |
| 2378 | |
| 2379 | rlock_acquire(rtld_bind_lock, &lockstate); |
| 2380 | obj = obj_from_addr(addr); |
| 2381 | if (obj == NULL) { |
| 2382 | _rtld_error("No shared object contains address"); |
| 2383 | lock_release(rtld_bind_lock, &lockstate); |
| 2384 | return (0); |
| 2385 | } |
| 2386 | rtld_fill_dl_phdr_info(obj, phdr_info); |
| 2387 | lock_release(rtld_bind_lock, &lockstate); |
| 2388 | return (1); |
| 2389 | } |
| 2390 | |
| 2391 | int |
| 2392 | dladdr(const void *addr, Dl_info *info) |
| 2393 | { |
| 2394 | const Obj_Entry *obj; |
| 2395 | const Elf_Sym *def; |
| 2396 | void *symbol_addr; |
| 2397 | unsigned long symoffset; |
| 2398 | RtldLockState lockstate; |
| 2399 | |
| 2400 | rlock_acquire(rtld_bind_lock, &lockstate); |
| 2401 | obj = obj_from_addr(addr); |
| 2402 | if (obj == NULL) { |
| 2403 | _rtld_error("No shared object contains address"); |
| 2404 | lock_release(rtld_bind_lock, &lockstate); |
| 2405 | return 0; |
| 2406 | } |
| 2407 | info->dli_fname = obj->path; |
| 2408 | info->dli_fbase = obj->mapbase; |
| 2409 | info->dli_saddr = NULL; |
| 2410 | info->dli_sname = NULL; |
| 2411 | |
| 2412 | /* |
| 2413 | * Walk the symbol list looking for the symbol whose address is |
| 2414 | * closest to the address sent in. |
| 2415 | */ |
| 2416 | for (symoffset = 0; symoffset < obj->nchains; symoffset++) { |
| 2417 | def = obj->symtab + symoffset; |
| 2418 | |
| 2419 | /* |
| 2420 | * For skip the symbol if st_shndx is either SHN_UNDEF or |
| 2421 | * SHN_COMMON. |
| 2422 | */ |
| 2423 | if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) |
| 2424 | continue; |
| 2425 | |
| 2426 | /* |
| 2427 | * If the symbol is greater than the specified address, or if it |
| 2428 | * is further away from addr than the current nearest symbol, |
| 2429 | * then reject it. |
| 2430 | */ |
| 2431 | symbol_addr = obj->relocbase + def->st_value; |
| 2432 | if (symbol_addr > addr || symbol_addr < info->dli_saddr) |
| 2433 | continue; |
| 2434 | |
| 2435 | /* Update our idea of the nearest symbol. */ |
| 2436 | info->dli_sname = obj->strtab + def->st_name; |
| 2437 | info->dli_saddr = symbol_addr; |
| 2438 | |
| 2439 | /* Exact match? */ |
| 2440 | if (info->dli_saddr == addr) |
| 2441 | break; |
| 2442 | } |
| 2443 | lock_release(rtld_bind_lock, &lockstate); |
| 2444 | return 1; |
| 2445 | } |
| 2446 | |
| 2447 | int |
| 2448 | dlinfo(void *handle, int request, void *p) |
| 2449 | { |
| 2450 | const Obj_Entry *obj; |
| 2451 | RtldLockState lockstate; |
| 2452 | int error; |
| 2453 | |
| 2454 | rlock_acquire(rtld_bind_lock, &lockstate); |
| 2455 | |
| 2456 | if (handle == NULL || handle == RTLD_SELF) { |
| 2457 | void *retaddr; |
| 2458 | |
| 2459 | retaddr = __builtin_return_address(0); /* __GNUC__ only */ |
| 2460 | if ((obj = obj_from_addr(retaddr)) == NULL) |
| 2461 | _rtld_error("Cannot determine caller's shared object"); |
| 2462 | } else |
| 2463 | obj = dlcheck(handle); |
| 2464 | |
| 2465 | if (obj == NULL) { |
| 2466 | lock_release(rtld_bind_lock, &lockstate); |
| 2467 | return (-1); |
| 2468 | } |
| 2469 | |
| 2470 | error = 0; |
| 2471 | switch (request) { |
| 2472 | case RTLD_DI_LINKMAP: |
| 2473 | *((struct link_map const **)p) = &obj->linkmap; |
| 2474 | break; |
| 2475 | case RTLD_DI_ORIGIN: |
| 2476 | error = rtld_dirname(obj->path, p); |
| 2477 | break; |
| 2478 | |
| 2479 | case RTLD_DI_SERINFOSIZE: |
| 2480 | case RTLD_DI_SERINFO: |
| 2481 | error = do_search_info(obj, request, (struct dl_serinfo *)p); |
| 2482 | break; |
| 2483 | |
| 2484 | default: |
| 2485 | _rtld_error("Invalid request %d passed to dlinfo()", request); |
| 2486 | error = -1; |
| 2487 | } |
| 2488 | |
| 2489 | lock_release(rtld_bind_lock, &lockstate); |
| 2490 | |
| 2491 | return (error); |
| 2492 | } |
| 2493 | |
| 2494 | static void |
| 2495 | rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) |
| 2496 | { |
| 2497 | |
| 2498 | phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; |
| 2499 | phdr_info->dlpi_name = STAILQ_FIRST(&obj->names) ? |
| 2500 | STAILQ_FIRST(&obj->names)->name : obj->path; |
| 2501 | phdr_info->dlpi_phdr = obj->phdr; |
| 2502 | phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); |
| 2503 | phdr_info->dlpi_tls_modid = obj->tlsindex; |
| 2504 | phdr_info->dlpi_tls_data = obj->tlsinit; |
| 2505 | phdr_info->dlpi_adds = obj_loads; |
| 2506 | phdr_info->dlpi_subs = obj_loads - obj_count; |
| 2507 | } |
| 2508 | |
| 2509 | int |
| 2510 | dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) |
| 2511 | { |
| 2512 | struct dl_phdr_info phdr_info; |
| 2513 | const Obj_Entry *obj; |
| 2514 | RtldLockState bind_lockstate, phdr_lockstate; |
| 2515 | int error; |
| 2516 | |
| 2517 | wlock_acquire(rtld_phdr_lock, &phdr_lockstate); |
| 2518 | rlock_acquire(rtld_bind_lock, &bind_lockstate); |
| 2519 | |
| 2520 | error = 0; |
| 2521 | |
| 2522 | for (obj = obj_list; obj != NULL; obj = obj->next) { |
| 2523 | rtld_fill_dl_phdr_info(obj, &phdr_info); |
| 2524 | if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0) |
| 2525 | break; |
| 2526 | |
| 2527 | } |
| 2528 | lock_release(rtld_bind_lock, &bind_lockstate); |
| 2529 | lock_release(rtld_phdr_lock, &phdr_lockstate); |
| 2530 | |
| 2531 | return (error); |
| 2532 | } |
| 2533 | |
| 2534 | struct fill_search_info_args { |
| 2535 | int request; |
| 2536 | unsigned int flags; |
| 2537 | Dl_serinfo *serinfo; |
| 2538 | Dl_serpath *serpath; |
| 2539 | char *strspace; |
| 2540 | }; |
| 2541 | |
| 2542 | static void * |
| 2543 | fill_search_info(const char *dir, size_t dirlen, void *param) |
| 2544 | { |
| 2545 | struct fill_search_info_args *arg; |
| 2546 | |
| 2547 | arg = param; |
| 2548 | |
| 2549 | if (arg->request == RTLD_DI_SERINFOSIZE) { |
| 2550 | arg->serinfo->dls_cnt ++; |
| 2551 | arg->serinfo->dls_size += sizeof(Dl_serpath) + dirlen + 1; |
| 2552 | } else { |
| 2553 | struct dl_serpath *s_entry; |
| 2554 | |
| 2555 | s_entry = arg->serpath; |
| 2556 | s_entry->dls_name = arg->strspace; |
| 2557 | s_entry->dls_flags = arg->flags; |
| 2558 | |
| 2559 | strncpy(arg->strspace, dir, dirlen); |
| 2560 | arg->strspace[dirlen] = '\0'; |
| 2561 | |
| 2562 | arg->strspace += dirlen + 1; |
| 2563 | arg->serpath++; |
| 2564 | } |
| 2565 | |
| 2566 | return (NULL); |
| 2567 | } |
| 2568 | |
| 2569 | static int |
| 2570 | do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) |
| 2571 | { |
| 2572 | struct dl_serinfo _info; |
| 2573 | struct fill_search_info_args args; |
| 2574 | |
| 2575 | args.request = RTLD_DI_SERINFOSIZE; |
| 2576 | args.serinfo = &_info; |
| 2577 | |
| 2578 | _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); |
| 2579 | _info.dls_cnt = 0; |
| 2580 | |
| 2581 | path_enumerate(ld_library_path, fill_search_info, &args); |
| 2582 | path_enumerate(obj->rpath, fill_search_info, &args); |
| 2583 | path_enumerate(gethints(), fill_search_info, &args); |
| 2584 | path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args); |
| 2585 | |
| 2586 | |
| 2587 | if (request == RTLD_DI_SERINFOSIZE) { |
| 2588 | info->dls_size = _info.dls_size; |
| 2589 | info->dls_cnt = _info.dls_cnt; |
| 2590 | return (0); |
| 2591 | } |
| 2592 | |
| 2593 | if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { |
| 2594 | _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); |
| 2595 | return (-1); |
| 2596 | } |
| 2597 | |
| 2598 | args.request = RTLD_DI_SERINFO; |
| 2599 | args.serinfo = info; |
| 2600 | args.serpath = &info->dls_serpath[0]; |
| 2601 | args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; |
| 2602 | |
| 2603 | args.flags = LA_SER_LIBPATH; |
| 2604 | if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL) |
| 2605 | return (-1); |
| 2606 | |
| 2607 | args.flags = LA_SER_RUNPATH; |
| 2608 | if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL) |
| 2609 | return (-1); |
| 2610 | |
| 2611 | args.flags = LA_SER_CONFIG; |
| 2612 | if (path_enumerate(gethints(), fill_search_info, &args) != NULL) |
| 2613 | return (-1); |
| 2614 | |
| 2615 | args.flags = LA_SER_DEFAULT; |
| 2616 | if (path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL) |
| 2617 | return (-1); |
| 2618 | return (0); |
| 2619 | } |
| 2620 | |
| 2621 | static int |
| 2622 | rtld_dirname(const char *path, char *bname) |
| 2623 | { |
| 2624 | const char *endp; |
| 2625 | |
| 2626 | /* Empty or NULL string gets treated as "." */ |
| 2627 | if (path == NULL || *path == '\0') { |
| 2628 | bname[0] = '.'; |
| 2629 | bname[1] = '\0'; |
| 2630 | return (0); |
| 2631 | } |
| 2632 | |
| 2633 | /* Strip trailing slashes */ |
| 2634 | endp = path + strlen(path) - 1; |
| 2635 | while (endp > path && *endp == '/') |
| 2636 | endp--; |
| 2637 | |
| 2638 | /* Find the start of the dir */ |
| 2639 | while (endp > path && *endp != '/') |
| 2640 | endp--; |
| 2641 | |
| 2642 | /* Either the dir is "/" or there are no slashes */ |
| 2643 | if (endp == path) { |
| 2644 | bname[0] = *endp == '/' ? '/' : '.'; |
| 2645 | bname[1] = '\0'; |
| 2646 | return (0); |
| 2647 | } else { |
| 2648 | do { |
| 2649 | endp--; |
| 2650 | } while (endp > path && *endp == '/'); |
| 2651 | } |
| 2652 | |
| 2653 | if (endp - path + 2 > PATH_MAX) |
| 2654 | { |
| 2655 | _rtld_error("Filename is too long: %s", path); |
| 2656 | return(-1); |
| 2657 | } |
| 2658 | |
| 2659 | strncpy(bname, path, endp - path + 1); |
| 2660 | bname[endp - path + 1] = '\0'; |
| 2661 | return (0); |
| 2662 | } |
| 2663 | |
| 2664 | static int |
| 2665 | rtld_dirname_abs(const char *path, char *base) |
| 2666 | { |
| 2667 | char base_rel[PATH_MAX]; |
| 2668 | |
| 2669 | if (rtld_dirname(path, base) == -1) |
| 2670 | return (-1); |
| 2671 | if (base[0] == '/') |
| 2672 | return (0); |
| 2673 | if (getcwd(base_rel, sizeof(base_rel)) == NULL || |
| 2674 | strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) || |
| 2675 | strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel)) |
| 2676 | return (-1); |
| 2677 | strcpy(base, base_rel); |
| 2678 | return (0); |
| 2679 | } |
| 2680 | |
| 2681 | static void |
| 2682 | linkmap_add(Obj_Entry *obj) |
| 2683 | { |
| 2684 | struct link_map *l = &obj->linkmap; |
| 2685 | struct link_map *prev; |
| 2686 | |
| 2687 | obj->linkmap.l_name = obj->path; |
| 2688 | obj->linkmap.l_addr = obj->mapbase; |
| 2689 | obj->linkmap.l_ld = obj->dynamic; |
| 2690 | #ifdef __mips__ |
| 2691 | /* GDB needs load offset on MIPS to use the symbols */ |
| 2692 | obj->linkmap.l_offs = obj->relocbase; |
| 2693 | #endif |
| 2694 | |
| 2695 | if (r_debug.r_map == NULL) { |
| 2696 | r_debug.r_map = l; |
| 2697 | return; |
| 2698 | } |
| 2699 | |
| 2700 | /* |
| 2701 | * Scan to the end of the list, but not past the entry for the |
| 2702 | * dynamic linker, which we want to keep at the very end. |
| 2703 | */ |
| 2704 | for (prev = r_debug.r_map; |
| 2705 | prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; |
| 2706 | prev = prev->l_next) |
| 2707 | ; |
| 2708 | |
| 2709 | /* Link in the new entry. */ |
| 2710 | l->l_prev = prev; |
| 2711 | l->l_next = prev->l_next; |
| 2712 | if (l->l_next != NULL) |
| 2713 | l->l_next->l_prev = l; |
| 2714 | prev->l_next = l; |
| 2715 | } |
| 2716 | |
| 2717 | static void |
| 2718 | linkmap_delete(Obj_Entry *obj) |
| 2719 | { |
| 2720 | struct link_map *l = &obj->linkmap; |
| 2721 | |
| 2722 | if (l->l_prev == NULL) { |
| 2723 | if ((r_debug.r_map = l->l_next) != NULL) |
| 2724 | l->l_next->l_prev = NULL; |
| 2725 | return; |
| 2726 | } |
| 2727 | |
| 2728 | if ((l->l_prev->l_next = l->l_next) != NULL) |
| 2729 | l->l_next->l_prev = l->l_prev; |
| 2730 | } |
| 2731 | |
| 2732 | /* |
| 2733 | * Function for the debugger to set a breakpoint on to gain control. |
| 2734 | * |
| 2735 | * The two parameters allow the debugger to easily find and determine |
| 2736 | * what the runtime loader is doing and to whom it is doing it. |
| 2737 | * |
| 2738 | * When the loadhook trap is hit (r_debug_state, set at program |
| 2739 | * initialization), the arguments can be found on the stack: |
| 2740 | * |
| 2741 | * +8 struct link_map *m |
| 2742 | * +4 struct r_debug *rd |
| 2743 | * +0 RetAddr |
| 2744 | */ |
| 2745 | void |
| 2746 | r_debug_state(struct r_debug* rd, struct link_map *m) |
| 2747 | { |
| 2748 | /* |
| 2749 | * The following is a hack to force the compiler to emit calls to |
| 2750 | * this function, even when optimizing. If the function is empty, |
| 2751 | * the compiler is not obliged to emit any code for calls to it, |
| 2752 | * even when marked __noinline. However, gdb depends on those |
| 2753 | * calls being made. |
| 2754 | */ |
| 2755 | __asm __volatile("" : : : "memory"); |
| 2756 | } |
| 2757 | |
| 2758 | /* |
| 2759 | * Get address of the pointer variable in the main program. |
| 2760 | */ |
| 2761 | static const void ** |
| 2762 | get_program_var_addr(const char *name) |
| 2763 | { |
| 2764 | const Obj_Entry *obj; |
| 2765 | unsigned long hash; |
| 2766 | |
| 2767 | hash = elf_hash(name); |
| 2768 | for (obj = obj_main; obj != NULL; obj = obj->next) { |
| 2769 | const Elf_Sym *def; |
| 2770 | |
| 2771 | if ((def = symlook_obj(name, hash, obj, NULL, 0)) != NULL) { |
| 2772 | const void **addr; |
| 2773 | |
| 2774 | addr = (const void **)(obj->relocbase + def->st_value); |
| 2775 | return addr; |
| 2776 | } |
| 2777 | } |
| 2778 | return (NULL); |
| 2779 | } |
| 2780 | |
| 2781 | /* |
| 2782 | * Set a pointer variable in the main program to the given value. This |
| 2783 | * is used to set key variables such as "environ" before any of the |
| 2784 | * init functions are called. |
| 2785 | */ |
| 2786 | static void |
| 2787 | set_program_var(const char *name, const void *value) |
| 2788 | { |
| 2789 | const void **addr; |
| 2790 | |
| 2791 | if ((addr = get_program_var_addr(name)) != NULL) { |
| 2792 | dbg("\"%s\": *%p <-- %p", name, addr, value); |
| 2793 | *addr = value; |
| 2794 | } |
| 2795 | } |
| 2796 | |
| 2797 | /* |
| 2798 | * This is a special version of getenv which is far more efficient |
| 2799 | * at finding LD_ environment vars. |
| 2800 | */ |
| 2801 | static |
| 2802 | const char * |
| 2803 | _getenv_ld(const char *id) |
| 2804 | { |
| 2805 | const char *envp; |
| 2806 | int i, j; |
| 2807 | int idlen = strlen(id); |
| 2808 | |
| 2809 | if (ld_index == LD_ARY_CACHE) |
| 2810 | return(getenv(id)); |
| 2811 | if (ld_index == 0) { |
| 2812 | for (i = j = 0; (envp = environ[i]) != NULL && j < LD_ARY_CACHE; ++i) { |
| 2813 | if (envp[0] == 'L' && envp[1] == 'D' && envp[2] == '_') |
| 2814 | ld_ary[j++] = envp; |
| 2815 | } |
| 2816 | if (j == 0) |
| 2817 | ld_ary[j++] = ""; |
| 2818 | ld_index = j; |
| 2819 | } |
| 2820 | for (i = ld_index - 1; i >= 0; --i) { |
| 2821 | if (strncmp(ld_ary[i], id, idlen) == 0 && ld_ary[i][idlen] == '=') |
| 2822 | return(ld_ary[i] + idlen + 1); |
| 2823 | } |
| 2824 | return(NULL); |
| 2825 | } |
| 2826 | |
| 2827 | /* |
| 2828 | * Given a symbol name in a referencing object, find the corresponding |
| 2829 | * definition of the symbol. Returns a pointer to the symbol, or NULL if |
| 2830 | * no definition was found. Returns a pointer to the Obj_Entry of the |
| 2831 | * defining object via the reference parameter DEFOBJ_OUT. |
| 2832 | */ |
| 2833 | static const Elf_Sym * |
| 2834 | symlook_default(const char *name, unsigned long hash, const Obj_Entry *refobj, |
| 2835 | const Obj_Entry **defobj_out, const Ver_Entry *ventry, int flags) |
| 2836 | { |
| 2837 | DoneList donelist; |
| 2838 | const Elf_Sym *def; |
| 2839 | const Elf_Sym *symp; |
| 2840 | const Obj_Entry *obj; |
| 2841 | const Obj_Entry *defobj; |
| 2842 | const Objlist_Entry *elm; |
| 2843 | def = NULL; |
| 2844 | defobj = NULL; |
| 2845 | donelist_init(&donelist); |
| 2846 | |
| 2847 | /* Look first in the referencing object if linked symbolically. */ |
| 2848 | if (refobj->symbolic && !donelist_check(&donelist, refobj)) { |
| 2849 | symp = symlook_obj(name, hash, refobj, ventry, flags); |
| 2850 | if (symp != NULL) { |
| 2851 | def = symp; |
| 2852 | defobj = refobj; |
| 2853 | } |
| 2854 | } |
| 2855 | |
| 2856 | /* Search all objects loaded at program start up. */ |
| 2857 | if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { |
| 2858 | symp = symlook_list(name, hash, &list_main, &obj, ventry, flags, |
| 2859 | &donelist); |
| 2860 | if (symp != NULL && |
| 2861 | (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) { |
| 2862 | def = symp; |
| 2863 | defobj = obj; |
| 2864 | } |
| 2865 | } |
| 2866 | |
| 2867 | /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ |
| 2868 | STAILQ_FOREACH(elm, &list_global, link) { |
| 2869 | if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK) |
| 2870 | break; |
| 2871 | symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, ventry, |
| 2872 | flags, &donelist); |
| 2873 | if (symp != NULL && |
| 2874 | (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) { |
| 2875 | def = symp; |
| 2876 | defobj = obj; |
| 2877 | } |
| 2878 | } |
| 2879 | |
| 2880 | /* Search all dlopened DAGs containing the referencing object. */ |
| 2881 | STAILQ_FOREACH(elm, &refobj->dldags, link) { |
| 2882 | if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK) |
| 2883 | break; |
| 2884 | symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, ventry, |
| 2885 | flags, &donelist); |
| 2886 | if (symp != NULL && |
| 2887 | (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) { |
| 2888 | def = symp; |
| 2889 | defobj = obj; |
| 2890 | } |
| 2891 | } |
| 2892 | |
| 2893 | /* |
| 2894 | * Search the dynamic linker itself, and possibly resolve the |
| 2895 | * symbol from there. This is how the application links to |
| 2896 | * dynamic linker services such as dlopen. Only the values listed |
| 2897 | * in the "exports" array can be resolved from the dynamic linker. |
| 2898 | */ |
| 2899 | if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { |
| 2900 | symp = symlook_obj(name, hash, &obj_rtld, ventry, flags); |
| 2901 | if (symp != NULL && is_exported(symp)) { |
| 2902 | def = symp; |
| 2903 | defobj = &obj_rtld; |
| 2904 | } |
| 2905 | } |
| 2906 | |
| 2907 | if (def != NULL) |
| 2908 | *defobj_out = defobj; |
| 2909 | return def; |
| 2910 | } |
| 2911 | |
| 2912 | static const Elf_Sym * |
| 2913 | symlook_list(const char *name, unsigned long hash, const Objlist *objlist, |
| 2914 | const Obj_Entry **defobj_out, const Ver_Entry *ventry, int flags, |
| 2915 | DoneList *dlp) |
| 2916 | { |
| 2917 | const Elf_Sym *symp; |
| 2918 | const Elf_Sym *def; |
| 2919 | const Obj_Entry *defobj; |
| 2920 | const Objlist_Entry *elm; |
| 2921 | |
| 2922 | def = NULL; |
| 2923 | defobj = NULL; |
| 2924 | STAILQ_FOREACH(elm, objlist, link) { |
| 2925 | if (donelist_check(dlp, elm->obj)) |
| 2926 | continue; |
| 2927 | if ((symp = symlook_obj(name, hash, elm->obj, ventry, flags)) != NULL) { |
| 2928 | if (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK) { |
| 2929 | def = symp; |
| 2930 | defobj = elm->obj; |
| 2931 | if (ELF_ST_BIND(def->st_info) != STB_WEAK) |
| 2932 | break; |
| 2933 | } |
| 2934 | } |
| 2935 | } |
| 2936 | if (def != NULL) |
| 2937 | *defobj_out = defobj; |
| 2938 | return def; |
| 2939 | } |
| 2940 | |
| 2941 | /* |
| 2942 | * Search the symbol table of a shared object and all objects needed |
| 2943 | * by it for a symbol of the given name. Search order is |
| 2944 | * breadth-first. Returns a pointer to the symbol, or NULL if no |
| 2945 | * definition was found. |
| 2946 | */ |
| 2947 | static const Elf_Sym * |
| 2948 | symlook_needed(const char *name, unsigned long hash, const Needed_Entry *needed, |
| 2949 | const Obj_Entry **defobj_out, const Ver_Entry *ventry, int flags, |
| 2950 | DoneList *dlp) |
| 2951 | { |
| 2952 | const Elf_Sym *def, *def_w; |
| 2953 | const Needed_Entry *n; |
| 2954 | const Obj_Entry *obj, *defobj, *defobj1; |
| 2955 | |
| 2956 | def = def_w = NULL; |
| 2957 | defobj = NULL; |
| 2958 | for (n = needed; n != NULL; n = n->next) { |
| 2959 | if ((obj = n->obj) == NULL || |
| 2960 | donelist_check(dlp, obj) || |
| 2961 | (def = symlook_obj(name, hash, obj, ventry, flags)) == NULL) |
| 2962 | continue; |
| 2963 | defobj = obj; |
| 2964 | if (ELF_ST_BIND(def->st_info) != STB_WEAK) { |
| 2965 | *defobj_out = defobj; |
| 2966 | return (def); |
| 2967 | } |
| 2968 | } |
| 2969 | /* |
| 2970 | * There we come when either symbol definition is not found in |
| 2971 | * directly needed objects, or found symbol is weak. |
| 2972 | */ |
| 2973 | for (n = needed; n != NULL; n = n->next) { |
| 2974 | if ((obj = n->obj) == NULL) |
| 2975 | continue; |
| 2976 | def_w = symlook_needed(name, hash, obj->needed, &defobj1, |
| 2977 | ventry, flags, dlp); |
| 2978 | if (def_w == NULL) |
| 2979 | continue; |
| 2980 | if (def == NULL || ELF_ST_BIND(def_w->st_info) != STB_WEAK) { |
| 2981 | def = def_w; |
| 2982 | defobj = defobj1; |
| 2983 | } |
| 2984 | if (ELF_ST_BIND(def_w->st_info) != STB_WEAK) |
| 2985 | break; |
| 2986 | } |
| 2987 | if (def != NULL) |
| 2988 | *defobj_out = defobj; |
| 2989 | return (def); |
| 2990 | } |
| 2991 | |
| 2992 | /* |
| 2993 | * Search the symbol table of a single shared object for a symbol of |
| 2994 | * the given name and version, if requested. Returns a pointer to the |
| 2995 | * symbol, or NULL if no definition was found. |
| 2996 | * |
| 2997 | * The symbol's hash value is passed in for efficiency reasons; that |
| 2998 | * eliminates many recomputations of the hash value. |
| 2999 | */ |
| 3000 | const Elf_Sym * |
| 3001 | symlook_obj(const char *name, unsigned long hash, const Obj_Entry *obj, |
| 3002 | const Ver_Entry *ventry, int flags) |
| 3003 | { |
| 3004 | unsigned long symnum; |
| 3005 | const Elf_Sym *vsymp; |
| 3006 | Elf_Versym verndx; |
| 3007 | int vcount; |
| 3008 | |
| 3009 | if (obj->buckets == NULL) |
| 3010 | return NULL; |
| 3011 | |
| 3012 | vsymp = NULL; |
| 3013 | vcount = 0; |
| 3014 | symnum = obj->buckets[hash % obj->nbuckets]; |
| 3015 | |
| 3016 | for (; symnum != STN_UNDEF; symnum = obj->chains[symnum]) { |
| 3017 | const Elf_Sym *symp; |
| 3018 | const char *strp; |
| 3019 | |
| 3020 | if (symnum >= obj->nchains) |
| 3021 | return NULL; /* Bad object */ |
| 3022 | |
| 3023 | symp = obj->symtab + symnum; |
| 3024 | strp = obj->strtab + symp->st_name; |
| 3025 | |
| 3026 | switch (ELF_ST_TYPE(symp->st_info)) { |
| 3027 | case STT_FUNC: |
| 3028 | case STT_NOTYPE: |
| 3029 | case STT_OBJECT: |
| 3030 | if (symp->st_value == 0) |
| 3031 | continue; |
| 3032 | /* fallthrough */ |
| 3033 | case STT_TLS: |
| 3034 | if (symp->st_shndx != SHN_UNDEF) |
| 3035 | break; |
| 3036 | else if (((flags & SYMLOOK_IN_PLT) == 0) && |
| 3037 | (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) |
| 3038 | break; |
| 3039 | /* fallthrough */ |
| 3040 | default: |
| 3041 | continue; |
| 3042 | } |
| 3043 | if (name[0] != strp[0] || strcmp(name, strp) != 0) |
| 3044 | continue; |
| 3045 | |
| 3046 | if (ventry == NULL) { |
| 3047 | if (obj->versyms != NULL) { |
| 3048 | verndx = VER_NDX(obj->versyms[symnum]); |
| 3049 | if (verndx > obj->vernum) { |
| 3050 | _rtld_error("%s: symbol %s references wrong version %d", |
| 3051 | obj->path, obj->strtab + symnum, verndx); |
| 3052 | continue; |
| 3053 | } |
| 3054 | /* |
| 3055 | * If we are not called from dlsym (i.e. this is a normal |
| 3056 | * relocation from unversioned binary), accept the symbol |
| 3057 | * immediately if it happens to have first version after |
| 3058 | * this shared object became versioned. Otherwise, if |
| 3059 | * symbol is versioned and not hidden, remember it. If it |
| 3060 | * is the only symbol with this name exported by the |
| 3061 | * shared object, it will be returned as a match at the |
| 3062 | * end of the function. If symbol is global (verndx < 2) |
| 3063 | * accept it unconditionally. |
| 3064 | */ |
| 3065 | if ((flags & SYMLOOK_DLSYM) == 0 && verndx == VER_NDX_GIVEN) |
| 3066 | return symp; |
| 3067 | else if (verndx >= VER_NDX_GIVEN) { |
| 3068 | if ((obj->versyms[symnum] & VER_NDX_HIDDEN) == 0) { |
| 3069 | if (vsymp == NULL) |
| 3070 | vsymp = symp; |
| 3071 | vcount ++; |
| 3072 | } |
| 3073 | continue; |
| 3074 | } |
| 3075 | } |
| 3076 | return symp; |
| 3077 | } else { |
| 3078 | if (obj->versyms == NULL) { |
| 3079 | if (object_match_name(obj, ventry->name)) { |
| 3080 | _rtld_error("%s: object %s should provide version %s for " |
| 3081 | "symbol %s", obj_rtld.path, obj->path, ventry->name, |
| 3082 | obj->strtab + symnum); |
| 3083 | continue; |
| 3084 | } |
| 3085 | } else { |
| 3086 | verndx = VER_NDX(obj->versyms[symnum]); |
| 3087 | if (verndx > obj->vernum) { |
| 3088 | _rtld_error("%s: symbol %s references wrong version %d", |
| 3089 | obj->path, obj->strtab + symnum, verndx); |
| 3090 | continue; |
| 3091 | } |
| 3092 | if (obj->vertab[verndx].hash != ventry->hash || |
| 3093 | strcmp(obj->vertab[verndx].name, ventry->name)) { |
| 3094 | /* |
| 3095 | * Version does not match. Look if this is a global symbol |
| 3096 | * and if it is not hidden. If global symbol (verndx < 2) |
| 3097 | * is available, use it. Do not return symbol if we are |
| 3098 | * called by dlvsym, because dlvsym looks for a specific |
| 3099 | * version and default one is not what dlvsym wants. |
| 3100 | */ |
| 3101 | if ((flags & SYMLOOK_DLSYM) || |
| 3102 | (obj->versyms[symnum] & VER_NDX_HIDDEN) || |
| 3103 | (verndx >= VER_NDX_GIVEN)) |
| 3104 | continue; |
| 3105 | } |
| 3106 | } |
| 3107 | return symp; |
| 3108 | } |
| 3109 | } |
| 3110 | return (vcount == 1) ? vsymp : NULL; |
| 3111 | } |
| 3112 | |
| 3113 | static void |
| 3114 | trace_loaded_objects(Obj_Entry *obj) |
| 3115 | { |
| 3116 | const char *fmt1, *fmt2, *fmt, *main_local, *list_containers; |
| 3117 | int c; |
| 3118 | |
| 3119 | if ((main_local = _getenv_ld("LD_TRACE_LOADED_OBJECTS_PROGNAME")) == NULL) |
| 3120 | main_local = ""; |
| 3121 | |
| 3122 | if ((fmt1 = _getenv_ld("LD_TRACE_LOADED_OBJECTS_FMT1")) == NULL) |
| 3123 | fmt1 = "\t%o => %p (%x)\n"; |
| 3124 | |
| 3125 | if ((fmt2 = _getenv_ld("LD_TRACE_LOADED_OBJECTS_FMT2")) == NULL) |
| 3126 | fmt2 = "\t%o (%x)\n"; |
| 3127 | |
| 3128 | list_containers = _getenv_ld("LD_TRACE_LOADED_OBJECTS_ALL"); |
| 3129 | |
| 3130 | for (; obj; obj = obj->next) { |
| 3131 | Needed_Entry *needed; |
| 3132 | char *name, *path; |
| 3133 | bool is_lib; |
| 3134 | |
| 3135 | if (list_containers && obj->needed != NULL) |
| 3136 | printf("%s:\n", obj->path); |
| 3137 | for (needed = obj->needed; needed; needed = needed->next) { |
| 3138 | if (needed->obj != NULL) { |
| 3139 | if (needed->obj->traced && !list_containers) |
| 3140 | continue; |
| 3141 | needed->obj->traced = true; |
| 3142 | path = needed->obj->path; |
| 3143 | } else |
| 3144 | path = "not found"; |
| 3145 | |
| 3146 | name = (char *)obj->strtab + needed->name; |
| 3147 | is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ |
| 3148 | |
| 3149 | fmt = is_lib ? fmt1 : fmt2; |
| 3150 | while ((c = *fmt++) != '\0') { |
| 3151 | switch (c) { |
| 3152 | default: |
| 3153 | putchar(c); |
| 3154 | continue; |
| 3155 | case '\\': |
| 3156 | switch (c = *fmt) { |
| 3157 | case '\0': |
| 3158 | continue; |
| 3159 | case 'n': |
| 3160 | putchar('\n'); |
| 3161 | break; |
| 3162 | case 't': |
| 3163 | putchar('\t'); |
| 3164 | break; |
| 3165 | } |
| 3166 | break; |
| 3167 | case '%': |
| 3168 | switch (c = *fmt) { |
| 3169 | case '\0': |
| 3170 | continue; |
| 3171 | case '%': |
| 3172 | default: |
| 3173 | putchar(c); |
| 3174 | break; |
| 3175 | case 'A': |
| 3176 | printf("%s", main_local); |
| 3177 | break; |
| 3178 | case 'a': |
| 3179 | printf("%s", obj_main->path); |
| 3180 | break; |
| 3181 | case 'o': |
| 3182 | printf("%s", name); |
| 3183 | break; |
| 3184 | case 'p': |
| 3185 | printf("%s", path); |
| 3186 | break; |
| 3187 | case 'x': |
| 3188 | printf("%p", needed->obj ? needed->obj->mapbase : 0); |
| 3189 | break; |
| 3190 | } |
| 3191 | break; |
| 3192 | } |
| 3193 | ++fmt; |
| 3194 | } |
| 3195 | } |
| 3196 | } |
| 3197 | } |
| 3198 | |
| 3199 | /* |
| 3200 | * Unload a dlopened object and its dependencies from memory and from |
| 3201 | * our data structures. It is assumed that the DAG rooted in the |
| 3202 | * object has already been unreferenced, and that the object has a |
| 3203 | * reference count of 0. |
| 3204 | */ |
| 3205 | static void |
| 3206 | unload_object(Obj_Entry *root) |
| 3207 | { |
| 3208 | Obj_Entry *obj; |
| 3209 | Obj_Entry **linkp; |
| 3210 | |
| 3211 | assert(root->refcount == 0); |
| 3212 | |
| 3213 | /* |
| 3214 | * Pass over the DAG removing unreferenced objects from |
| 3215 | * appropriate lists. |
| 3216 | */ |
| 3217 | unlink_object(root); |
| 3218 | |
| 3219 | /* Unmap all objects that are no longer referenced. */ |
| 3220 | linkp = &obj_list->next; |
| 3221 | while ((obj = *linkp) != NULL) { |
| 3222 | if (obj->refcount == 0) { |
| 3223 | LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, |
| 3224 | obj->path); |
| 3225 | dbg("unloading \"%s\"", obj->path); |
| 3226 | munmap(obj->mapbase, obj->mapsize); |
| 3227 | linkmap_delete(obj); |
| 3228 | *linkp = obj->next; |
| 3229 | obj_count--; |
| 3230 | obj_free(obj); |
| 3231 | } else |
| 3232 | linkp = &obj->next; |
| 3233 | } |
| 3234 | obj_tail = linkp; |
| 3235 | } |
| 3236 | |
| 3237 | static void |
| 3238 | unlink_object(Obj_Entry *root) |
| 3239 | { |
| 3240 | Objlist_Entry *elm; |
| 3241 | |
| 3242 | if (root->refcount == 0) { |
| 3243 | /* Remove the object from the RTLD_GLOBAL list. */ |
| 3244 | objlist_remove(&list_global, root); |
| 3245 | |
| 3246 | /* Remove the object from all objects' DAG lists. */ |
| 3247 | STAILQ_FOREACH(elm, &root->dagmembers, link) { |
| 3248 | objlist_remove(&elm->obj->dldags, root); |
| 3249 | if (elm->obj != root) |
| 3250 | unlink_object(elm->obj); |
| 3251 | } |
| 3252 | } |
| 3253 | } |
| 3254 | |
| 3255 | static void |
| 3256 | ref_dag(Obj_Entry *root) |
| 3257 | { |
| 3258 | Objlist_Entry *elm; |
| 3259 | |
| 3260 | assert(root->dag_inited); |
| 3261 | STAILQ_FOREACH(elm, &root->dagmembers, link) |
| 3262 | elm->obj->refcount++; |
| 3263 | } |
| 3264 | |
| 3265 | static void |
| 3266 | unref_dag(Obj_Entry *root) |
| 3267 | { |
| 3268 | Objlist_Entry *elm; |
| 3269 | |
| 3270 | assert(root->dag_inited); |
| 3271 | STAILQ_FOREACH(elm, &root->dagmembers, link) |
| 3272 | elm->obj->refcount--; |
| 3273 | } |
| 3274 | |
| 3275 | /* |
| 3276 | * Common code for MD __tls_get_addr(). |
| 3277 | */ |
| 3278 | void * |
| 3279 | tls_get_addr_common(Elf_Addr** dtvp, int index, size_t offset) |
| 3280 | { |
| 3281 | Elf_Addr* dtv = *dtvp; |
| 3282 | RtldLockState lockstate; |
| 3283 | |
| 3284 | /* Check dtv generation in case new modules have arrived */ |
| 3285 | if (dtv[0] != tls_dtv_generation) { |
| 3286 | Elf_Addr* newdtv; |
| 3287 | int to_copy; |
| 3288 | |
| 3289 | wlock_acquire(rtld_bind_lock, &lockstate); |
| 3290 | newdtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr)); |
| 3291 | to_copy = dtv[1]; |
| 3292 | if (to_copy > tls_max_index) |
| 3293 | to_copy = tls_max_index; |
| 3294 | memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); |
| 3295 | newdtv[0] = tls_dtv_generation; |
| 3296 | newdtv[1] = tls_max_index; |
| 3297 | free(dtv); |
| 3298 | lock_release(rtld_bind_lock, &lockstate); |
| 3299 | dtv = *dtvp = newdtv; |
| 3300 | } |
| 3301 | |
| 3302 | /* Dynamically allocate module TLS if necessary */ |
| 3303 | if (!dtv[index + 1]) { |
| 3304 | /* Signal safe, wlock will block out signals. */ |
| 3305 | wlock_acquire(rtld_bind_lock, &lockstate); |
| 3306 | if (!dtv[index + 1]) |
| 3307 | dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); |
| 3308 | lock_release(rtld_bind_lock, &lockstate); |
| 3309 | } |
| 3310 | return (void*) (dtv[index + 1] + offset); |
| 3311 | } |
| 3312 | |
| 3313 | #if defined(RTLD_STATIC_TLS_VARIANT_II) |
| 3314 | |
| 3315 | /* |
| 3316 | * Allocate the static TLS area. Return a pointer to the TCB. The |
| 3317 | * static area is based on negative offsets relative to the tcb. |
| 3318 | * |
| 3319 | * The TCB contains an errno pointer for the system call layer, but because |
| 3320 | * we are the RTLD we really have no idea how the caller was compiled so |
| 3321 | * the information has to be passed in. errno can either be: |
| 3322 | * |
| 3323 | * type 0 errno is a simple non-TLS global pointer. |
| 3324 | * (special case for e.g. libc_rtld) |
| 3325 | * type 1 errno accessed by GOT entry (dynamically linked programs) |
| 3326 | * type 2 errno accessed by %gs:OFFSET (statically linked programs) |
| 3327 | */ |
| 3328 | struct tls_tcb * |
| 3329 | allocate_tls(Obj_Entry *objs) |
| 3330 | { |
| 3331 | Obj_Entry *obj; |
| 3332 | size_t data_size; |
| 3333 | size_t dtv_size; |
| 3334 | struct tls_tcb *tcb; |
| 3335 | Elf_Addr *dtv; |
| 3336 | Elf_Addr addr; |
| 3337 | |
| 3338 | /* |
| 3339 | * Allocate the new TCB. static TLS storage is placed just before the |
| 3340 | * TCB to support the %gs:OFFSET (negative offset) model. |
| 3341 | */ |
| 3342 | data_size = (tls_static_space + RTLD_STATIC_TLS_ALIGN_MASK) & |
| 3343 | ~RTLD_STATIC_TLS_ALIGN_MASK; |
| 3344 | tcb = malloc(data_size + sizeof(*tcb)); |
| 3345 | tcb = (void *)((char *)tcb + data_size); /* actual tcb location */ |
| 3346 | |
| 3347 | dtv_size = (tls_max_index + 2) * sizeof(Elf_Addr); |
| 3348 | dtv = malloc(dtv_size); |
| 3349 | bzero(dtv, dtv_size); |
| 3350 | |
| 3351 | #ifdef RTLD_TCB_HAS_SELF_POINTER |
| 3352 | tcb->tcb_self = tcb; |
| 3353 | #endif |
| 3354 | tcb->tcb_dtv = dtv; |
| 3355 | tcb->tcb_pthread = NULL; |
| 3356 | |
| 3357 | dtv[0] = tls_dtv_generation; |
| 3358 | dtv[1] = tls_max_index; |
| 3359 | |
| 3360 | for (obj = objs; obj; obj = obj->next) { |
| 3361 | if (obj->tlsoffset) { |
| 3362 | addr = (Elf_Addr)tcb - obj->tlsoffset; |
| 3363 | memset((void *)(addr + obj->tlsinitsize), |
| 3364 | 0, obj->tlssize - obj->tlsinitsize); |
| 3365 | if (obj->tlsinit) |
| 3366 | memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); |
| 3367 | dtv[obj->tlsindex + 1] = addr; |
| 3368 | } |
| 3369 | } |
| 3370 | return(tcb); |
| 3371 | } |
| 3372 | |
| 3373 | void |
| 3374 | free_tls(struct tls_tcb *tcb) |
| 3375 | { |
| 3376 | Elf_Addr *dtv; |
| 3377 | int dtv_size, i; |
| 3378 | Elf_Addr tls_start, tls_end; |
| 3379 | size_t data_size; |
| 3380 | |
| 3381 | data_size = (tls_static_space + RTLD_STATIC_TLS_ALIGN_MASK) & |
| 3382 | ~RTLD_STATIC_TLS_ALIGN_MASK; |
| 3383 | |
| 3384 | dtv = tcb->tcb_dtv; |
| 3385 | dtv_size = dtv[1]; |
| 3386 | tls_end = (Elf_Addr)tcb; |
| 3387 | tls_start = (Elf_Addr)tcb - data_size; |
| 3388 | for (i = 0; i < dtv_size; i++) { |
| 3389 | if (dtv[i+2] != 0 && (dtv[i+2] < tls_start || dtv[i+2] > tls_end)) { |
| 3390 | free((void *)dtv[i+2]); |
| 3391 | } |
| 3392 | } |
| 3393 | |
| 3394 | free((void*) tls_start); |
| 3395 | } |
| 3396 | |
| 3397 | #else |
| 3398 | #error "Unsupported TLS layout" |
| 3399 | #endif |
| 3400 | |
| 3401 | /* |
| 3402 | * Allocate TLS block for module with given index. |
| 3403 | */ |
| 3404 | void * |
| 3405 | allocate_module_tls(int index) |
| 3406 | { |
| 3407 | Obj_Entry* obj; |
| 3408 | char* p; |
| 3409 | |
| 3410 | for (obj = obj_list; obj; obj = obj->next) { |
| 3411 | if (obj->tlsindex == index) |
| 3412 | break; |
| 3413 | } |
| 3414 | if (!obj) { |
| 3415 | _rtld_error("Can't find module with TLS index %d", index); |
| 3416 | die(); |
| 3417 | } |
| 3418 | |
| 3419 | p = malloc(obj->tlssize); |
| 3420 | if (p == NULL) { |
| 3421 | _rtld_error("Cannot allocate TLS block for index %d", index); |
| 3422 | die(); |
| 3423 | } |
| 3424 | memcpy(p, obj->tlsinit, obj->tlsinitsize); |
| 3425 | memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); |
| 3426 | |
| 3427 | return p; |
| 3428 | } |
| 3429 | |
| 3430 | bool |
| 3431 | allocate_tls_offset(Obj_Entry *obj) |
| 3432 | { |
| 3433 | size_t off; |
| 3434 | |
| 3435 | if (obj->tls_done) |
| 3436 | return true; |
| 3437 | |
| 3438 | if (obj->tlssize == 0) { |
| 3439 | obj->tls_done = true; |
| 3440 | return true; |
| 3441 | } |
| 3442 | |
| 3443 | if (obj->tlsindex == 1) |
| 3444 | off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign); |
| 3445 | else |
| 3446 | off = calculate_tls_offset(tls_last_offset, tls_last_size, |
| 3447 | obj->tlssize, obj->tlsalign); |
| 3448 | |
| 3449 | /* |
| 3450 | * If we have already fixed the size of the static TLS block, we |
| 3451 | * must stay within that size. When allocating the static TLS, we |
| 3452 | * leave a small amount of space spare to be used for dynamically |
| 3453 | * loading modules which use static TLS. |
| 3454 | */ |
| 3455 | if (tls_static_space) { |
| 3456 | if (calculate_tls_end(off, obj->tlssize) > tls_static_space) |
| 3457 | return false; |
| 3458 | } |
| 3459 | |
| 3460 | tls_last_offset = obj->tlsoffset = off; |
| 3461 | tls_last_size = obj->tlssize; |
| 3462 | obj->tls_done = true; |
| 3463 | |
| 3464 | return true; |
| 3465 | } |
| 3466 | |
| 3467 | void |
| 3468 | free_tls_offset(Obj_Entry *obj) |
| 3469 | { |
| 3470 | #ifdef RTLD_STATIC_TLS_VARIANT_II |
| 3471 | /* |
| 3472 | * If we were the last thing to allocate out of the static TLS |
| 3473 | * block, we give our space back to the 'allocator'. This is a |
| 3474 | * simplistic workaround to allow libGL.so.1 to be loaded and |
| 3475 | * unloaded multiple times. We only handle the Variant II |
| 3476 | * mechanism for now - this really needs a proper allocator. |
| 3477 | */ |
| 3478 | if (calculate_tls_end(obj->tlsoffset, obj->tlssize) |
| 3479 | == calculate_tls_end(tls_last_offset, tls_last_size)) { |
| 3480 | tls_last_offset -= obj->tlssize; |
| 3481 | tls_last_size = 0; |
| 3482 | } |
| 3483 | #endif |
| 3484 | } |
| 3485 | |
| 3486 | struct tls_tcb * |
| 3487 | _rtld_allocate_tls(void) |
| 3488 | { |
| 3489 | struct tls_tcb *new_tcb; |
| 3490 | RtldLockState lockstate; |
| 3491 | |
| 3492 | wlock_acquire(rtld_bind_lock, &lockstate); |
| 3493 | new_tcb = allocate_tls(obj_list); |
| 3494 | lock_release(rtld_bind_lock, &lockstate); |
| 3495 | return (new_tcb); |
| 3496 | } |
| 3497 | |
| 3498 | void |
| 3499 | _rtld_free_tls(struct tls_tcb *tcb) |
| 3500 | { |
| 3501 | RtldLockState lockstate; |
| 3502 | |
| 3503 | wlock_acquire(rtld_bind_lock, &lockstate); |
| 3504 | free_tls(tcb); |
| 3505 | lock_release(rtld_bind_lock, &lockstate); |
| 3506 | } |
| 3507 | |
| 3508 | static void |
| 3509 | object_add_name(Obj_Entry *obj, const char *name) |
| 3510 | { |
| 3511 | Name_Entry *entry; |
| 3512 | size_t len; |
| 3513 | |
| 3514 | len = strlen(name); |
| 3515 | entry = malloc(sizeof(Name_Entry) + len); |
| 3516 | |
| 3517 | if (entry != NULL) { |
| 3518 | strcpy(entry->name, name); |
| 3519 | STAILQ_INSERT_TAIL(&obj->names, entry, link); |
| 3520 | } |
| 3521 | } |
| 3522 | |
| 3523 | static int |
| 3524 | object_match_name(const Obj_Entry *obj, const char *name) |
| 3525 | { |
| 3526 | Name_Entry *entry; |
| 3527 | |
| 3528 | STAILQ_FOREACH(entry, &obj->names, link) { |
| 3529 | if (strcmp(name, entry->name) == 0) |
| 3530 | return (1); |
| 3531 | } |
| 3532 | return (0); |
| 3533 | } |
| 3534 | |
| 3535 | static Obj_Entry * |
| 3536 | locate_dependency(const Obj_Entry *obj, const char *name) |
| 3537 | { |
| 3538 | const Objlist_Entry *entry; |
| 3539 | const Needed_Entry *needed; |
| 3540 | |
| 3541 | STAILQ_FOREACH(entry, &list_main, link) { |
| 3542 | if (object_match_name(entry->obj, name)) |
| 3543 | return entry->obj; |
| 3544 | } |
| 3545 | |
| 3546 | for (needed = obj->needed; needed != NULL; needed = needed->next) { |
| 3547 | if (strcmp(obj->strtab + needed->name, name) == 0 || |
| 3548 | (needed->obj != NULL && object_match_name(needed->obj, name))) { |
| 3549 | /* |
| 3550 | * If there is DT_NEEDED for the name we are looking for, |
| 3551 | * we are all set. Note that object might not be found if |
| 3552 | * dependency was not loaded yet, so the function can |
| 3553 | * return NULL here. This is expected and handled |
| 3554 | * properly by the caller. |
| 3555 | */ |
| 3556 | return (needed->obj); |
| 3557 | } |
| 3558 | } |
| 3559 | _rtld_error("%s: Unexpected inconsistency: dependency %s not found", |
| 3560 | obj->path, name); |
| 3561 | die(); |
| 3562 | } |
| 3563 | |
| 3564 | static int |
| 3565 | check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, |
| 3566 | const Elf_Vernaux *vna) |
| 3567 | { |
| 3568 | const Elf_Verdef *vd; |
| 3569 | const char *vername; |
| 3570 | |
| 3571 | vername = refobj->strtab + vna->vna_name; |
| 3572 | vd = depobj->verdef; |
| 3573 | if (vd == NULL) { |
| 3574 | _rtld_error("%s: version %s required by %s not defined", |
| 3575 | depobj->path, vername, refobj->path); |
| 3576 | return (-1); |
| 3577 | } |
| 3578 | for (;;) { |
| 3579 | if (vd->vd_version != VER_DEF_CURRENT) { |
| 3580 | _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", |
| 3581 | depobj->path, vd->vd_version); |
| 3582 | return (-1); |
| 3583 | } |
| 3584 | if (vna->vna_hash == vd->vd_hash) { |
| 3585 | const Elf_Verdaux *aux = (const Elf_Verdaux *) |
| 3586 | ((char *)vd + vd->vd_aux); |
| 3587 | if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) |
| 3588 | return (0); |
| 3589 | } |
| 3590 | if (vd->vd_next == 0) |
| 3591 | break; |
| 3592 | vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); |
| 3593 | } |
| 3594 | if (vna->vna_flags & VER_FLG_WEAK) |
| 3595 | return (0); |
| 3596 | _rtld_error("%s: version %s required by %s not found", |
| 3597 | depobj->path, vername, refobj->path); |
| 3598 | return (-1); |
| 3599 | } |
| 3600 | |
| 3601 | static int |
| 3602 | rtld_verify_object_versions(Obj_Entry *obj) |
| 3603 | { |
| 3604 | const Elf_Verneed *vn; |
| 3605 | const Elf_Verdef *vd; |
| 3606 | const Elf_Verdaux *vda; |
| 3607 | const Elf_Vernaux *vna; |
| 3608 | const Obj_Entry *depobj; |
| 3609 | int maxvernum, vernum; |
| 3610 | |
| 3611 | maxvernum = 0; |
| 3612 | /* |
| 3613 | * Walk over defined and required version records and figure out |
| 3614 | * max index used by any of them. Do very basic sanity checking |
| 3615 | * while there. |
| 3616 | */ |
| 3617 | vn = obj->verneed; |
| 3618 | while (vn != NULL) { |
| 3619 | if (vn->vn_version != VER_NEED_CURRENT) { |
| 3620 | _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", |
| 3621 | obj->path, vn->vn_version); |
| 3622 | return (-1); |
| 3623 | } |
| 3624 | vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); |
| 3625 | for (;;) { |
| 3626 | vernum = VER_NEED_IDX(vna->vna_other); |
| 3627 | if (vernum > maxvernum) |
| 3628 | maxvernum = vernum; |
| 3629 | if (vna->vna_next == 0) |
| 3630 | break; |
| 3631 | vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); |
| 3632 | } |
| 3633 | if (vn->vn_next == 0) |
| 3634 | break; |
| 3635 | vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); |
| 3636 | } |
| 3637 | |
| 3638 | vd = obj->verdef; |
| 3639 | while (vd != NULL) { |
| 3640 | if (vd->vd_version != VER_DEF_CURRENT) { |
| 3641 | _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", |
| 3642 | obj->path, vd->vd_version); |
| 3643 | return (-1); |
| 3644 | } |
| 3645 | vernum = VER_DEF_IDX(vd->vd_ndx); |
| 3646 | if (vernum > maxvernum) |
| 3647 | maxvernum = vernum; |
| 3648 | if (vd->vd_next == 0) |
| 3649 | break; |
| 3650 | vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); |
| 3651 | } |
| 3652 | |
| 3653 | if (maxvernum == 0) |
| 3654 | return (0); |
| 3655 | |
| 3656 | /* |
| 3657 | * Store version information in array indexable by version index. |
| 3658 | * Verify that object version requirements are satisfied along the |
| 3659 | * way. |
| 3660 | */ |
| 3661 | obj->vernum = maxvernum + 1; |
| 3662 | obj->vertab = calloc(obj->vernum, sizeof(Ver_Entry)); |
| 3663 | |
| 3664 | vd = obj->verdef; |
| 3665 | while (vd != NULL) { |
| 3666 | if ((vd->vd_flags & VER_FLG_BASE) == 0) { |
| 3667 | vernum = VER_DEF_IDX(vd->vd_ndx); |
| 3668 | assert(vernum <= maxvernum); |
| 3669 | vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux); |
| 3670 | obj->vertab[vernum].hash = vd->vd_hash; |
| 3671 | obj->vertab[vernum].name = obj->strtab + vda->vda_name; |
| 3672 | obj->vertab[vernum].file = NULL; |
| 3673 | obj->vertab[vernum].flags = 0; |
| 3674 | } |
| 3675 | if (vd->vd_next == 0) |
| 3676 | break; |
| 3677 | vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); |
| 3678 | } |
| 3679 | |
| 3680 | vn = obj->verneed; |
| 3681 | while (vn != NULL) { |
| 3682 | depobj = locate_dependency(obj, obj->strtab + vn->vn_file); |
| 3683 | if (depobj == NULL) |
| 3684 | return (-1); |
| 3685 | vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); |
| 3686 | for (;;) { |
| 3687 | if (check_object_provided_version(obj, depobj, vna)) |
| 3688 | return (-1); |
| 3689 | vernum = VER_NEED_IDX(vna->vna_other); |
| 3690 | assert(vernum <= maxvernum); |
| 3691 | obj->vertab[vernum].hash = vna->vna_hash; |
| 3692 | obj->vertab[vernum].name = obj->strtab + vna->vna_name; |
| 3693 | obj->vertab[vernum].file = obj->strtab + vn->vn_file; |
| 3694 | obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? |
| 3695 | VER_INFO_HIDDEN : 0; |
| 3696 | if (vna->vna_next == 0) |
| 3697 | break; |
| 3698 | vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); |
| 3699 | } |
| 3700 | if (vn->vn_next == 0) |
| 3701 | break; |
| 3702 | vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); |
| 3703 | } |
| 3704 | return 0; |
| 3705 | } |
| 3706 | |
| 3707 | static int |
| 3708 | rtld_verify_versions(const Objlist *objlist) |
| 3709 | { |
| 3710 | Objlist_Entry *entry; |
| 3711 | int rc; |
| 3712 | |
| 3713 | rc = 0; |
| 3714 | STAILQ_FOREACH(entry, objlist, link) { |
| 3715 | /* |
| 3716 | * Skip dummy objects or objects that have their version requirements |
| 3717 | * already checked. |
| 3718 | */ |
| 3719 | if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) |
| 3720 | continue; |
| 3721 | if (rtld_verify_object_versions(entry->obj) == -1) { |
| 3722 | rc = -1; |
| 3723 | if (ld_tracing == NULL) |
| 3724 | break; |
| 3725 | } |
| 3726 | } |
| 3727 | if (rc == 0 || ld_tracing != NULL) |
| 3728 | rc = rtld_verify_object_versions(&obj_rtld); |
| 3729 | return rc; |
| 3730 | } |
| 3731 | |
| 3732 | const Ver_Entry * |
| 3733 | fetch_ventry(const Obj_Entry *obj, unsigned long symnum) |
| 3734 | { |
| 3735 | Elf_Versym vernum; |
| 3736 | |
| 3737 | if (obj->vertab) { |
| 3738 | vernum = VER_NDX(obj->versyms[symnum]); |
| 3739 | if (vernum >= obj->vernum) { |
| 3740 | _rtld_error("%s: symbol %s has wrong verneed value %d", |
| 3741 | obj->path, obj->strtab + symnum, vernum); |
| 3742 | } else if (obj->vertab[vernum].hash != 0) { |
| 3743 | return &obj->vertab[vernum]; |
| 3744 | } |
| 3745 | } |
| 3746 | return NULL; |
| 3747 | } |
| 3748 | |
| 3749 | /* |
| 3750 | * No unresolved symbols for rtld. |
| 3751 | */ |
| 3752 | void |
| 3753 | __pthread_cxa_finalize(struct dl_phdr_info *a) |
| 3754 | { |
| 3755 | } |