xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* Run time dynamic linker. |
| 2 | Copyright (C) 1995-2016 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | |
| 5 | The GNU C Library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2.1 of the License, or (at your option) any later version. |
| 9 | |
| 10 | The GNU C Library is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with the GNU C Library; if not, see |
| 17 | <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #include <errno.h> |
| 20 | #include <dlfcn.h> |
| 21 | #include <fcntl.h> |
| 22 | #include <stdbool.h> |
| 23 | #include <stdlib.h> |
| 24 | #include <string.h> |
| 25 | #include <unistd.h> |
| 26 | #include <sys/mman.h> |
| 27 | #include <sys/param.h> |
| 28 | #include <sys/stat.h> |
| 29 | #include <ldsodefs.h> |
| 30 | #include <_itoa.h> |
| 31 | #include <entry.h> |
| 32 | #include <fpu_control.h> |
| 33 | #include <hp-timing.h> |
| 34 | #include <libc-lock.h> |
| 35 | #include "dynamic-link.h" |
| 36 | #include <dl-librecon.h> |
| 37 | #include <unsecvars.h> |
| 38 | #include <dl-cache.h> |
| 39 | #include <dl-osinfo.h> |
| 40 | #include <dl-procinfo.h> |
| 41 | #include <tls.h> |
| 42 | #include <stap-probe.h> |
| 43 | #include <stackinfo.h> |
| 44 | |
| 45 | #include <assert.h> |
| 46 | |
| 47 | /* Avoid PLT use for our local calls at startup. */ |
| 48 | extern __typeof (__mempcpy) __mempcpy attribute_hidden; |
| 49 | |
| 50 | /* GCC has mental blocks about _exit. */ |
| 51 | extern __typeof (_exit) exit_internal asm ("_exit") attribute_hidden; |
| 52 | #define _exit exit_internal |
| 53 | |
| 54 | /* Helper function to handle errors while resolving symbols. */ |
| 55 | static void print_unresolved (int errcode, const char *objname, |
| 56 | const char *errsting); |
| 57 | |
| 58 | /* Helper function to handle errors when a version is missing. */ |
| 59 | static void print_missing_version (int errcode, const char *objname, |
| 60 | const char *errsting); |
| 61 | |
| 62 | /* Print the various times we collected. */ |
| 63 | static void print_statistics (hp_timing_t *total_timep); |
| 64 | |
| 65 | /* Add audit objects. */ |
| 66 | static void process_dl_audit (char *str); |
| 67 | |
| 68 | /* This is a list of all the modes the dynamic loader can be in. */ |
| 69 | enum mode { normal, list, verify, trace }; |
| 70 | |
| 71 | /* Process all environments variables the dynamic linker must recognize. |
| 72 | Since all of them start with `LD_' we are a bit smarter while finding |
| 73 | all the entries. */ |
| 74 | static void process_envvars (enum mode *modep); |
| 75 | |
| 76 | #ifdef DL_ARGV_NOT_RELRO |
| 77 | int _dl_argc attribute_hidden; |
| 78 | char **_dl_argv = NULL; |
| 79 | /* Nonzero if we were run directly. */ |
| 80 | unsigned int _dl_skip_args attribute_hidden; |
| 81 | #else |
| 82 | int _dl_argc attribute_relro attribute_hidden; |
| 83 | char **_dl_argv attribute_relro = NULL; |
| 84 | unsigned int _dl_skip_args attribute_relro attribute_hidden; |
| 85 | #endif |
| 86 | rtld_hidden_data_def (_dl_argv) |
| 87 | |
| 88 | #ifndef THREAD_SET_STACK_GUARD |
| 89 | /* Only exported for architectures that don't store the stack guard canary |
| 90 | in thread local area. */ |
| 91 | uintptr_t __stack_chk_guard attribute_relro; |
| 92 | #endif |
| 93 | |
| 94 | /* Only exported for architectures that don't store the pointer guard |
| 95 | value in thread local area. */ |
| 96 | uintptr_t __pointer_chk_guard_local |
| 97 | attribute_relro attribute_hidden __attribute__ ((nocommon)); |
| 98 | #ifndef THREAD_SET_POINTER_GUARD |
| 99 | strong_alias (__pointer_chk_guard_local, __pointer_chk_guard) |
| 100 | #endif |
| 101 | |
| 102 | |
| 103 | /* List of auditing DSOs. */ |
| 104 | static struct audit_list |
| 105 | { |
| 106 | const char *name; |
| 107 | struct audit_list *next; |
| 108 | } *audit_list; |
| 109 | |
| 110 | #ifndef HAVE_INLINED_SYSCALLS |
| 111 | /* Set nonzero during loading and initialization of executable and |
| 112 | libraries, cleared before the executable's entry point runs. This |
| 113 | must not be initialized to nonzero, because the unused dynamic |
| 114 | linker loaded in for libc.so's "ld.so.1" dep will provide the |
| 115 | definition seen by libc.so's initializer; that value must be zero, |
| 116 | and will be since that dynamic linker's _dl_start and dl_main will |
| 117 | never be called. */ |
| 118 | int _dl_starting_up = 0; |
| 119 | rtld_hidden_def (_dl_starting_up) |
| 120 | #endif |
| 121 | |
| 122 | /* This is the structure which defines all variables global to ld.so |
| 123 | (except those which cannot be added for some reason). */ |
| 124 | struct rtld_global _rtld_global = |
| 125 | { |
| 126 | /* Generally the default presumption without further information is an |
| 127 | * executable stack but this is not true for all platforms. */ |
| 128 | ._dl_stack_flags = DEFAULT_STACK_PERMS, |
| 129 | #ifdef _LIBC_REENTRANT |
| 130 | ._dl_load_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER, |
| 131 | ._dl_load_write_lock = _RTLD_LOCK_RECURSIVE_INITIALIZER, |
| 132 | #endif |
| 133 | ._dl_nns = 1, |
| 134 | ._dl_ns = |
| 135 | { |
| 136 | #ifdef _LIBC_REENTRANT |
| 137 | [LM_ID_BASE] = { ._ns_unique_sym_table |
| 138 | = { .lock = _RTLD_LOCK_RECURSIVE_INITIALIZER } } |
| 139 | #endif |
| 140 | } |
| 141 | }; |
| 142 | /* If we would use strong_alias here the compiler would see a |
| 143 | non-hidden definition. This would undo the effect of the previous |
| 144 | declaration. So spell out was strong_alias does plus add the |
| 145 | visibility attribute. */ |
| 146 | extern struct rtld_global _rtld_local |
| 147 | __attribute__ ((alias ("_rtld_global"), visibility ("hidden"))); |
| 148 | |
| 149 | |
| 150 | /* This variable is similar to _rtld_local, but all values are |
| 151 | read-only after relocation. */ |
| 152 | struct rtld_global_ro _rtld_global_ro attribute_relro = |
| 153 | { |
| 154 | /* Get architecture specific initializer. */ |
| 155 | #include <dl-procinfo.c> |
| 156 | #ifdef NEED_DL_SYSINFO |
| 157 | ._dl_sysinfo = DL_SYSINFO_DEFAULT, |
| 158 | #endif |
| 159 | ._dl_debug_fd = STDERR_FILENO, |
| 160 | ._dl_use_load_bias = -2, |
| 161 | ._dl_correct_cache_id = _DL_CACHE_DEFAULT_ID, |
| 162 | ._dl_hwcap_mask = HWCAP_IMPORTANT, |
| 163 | ._dl_lazy = 1, |
| 164 | ._dl_fpu_control = _FPU_DEFAULT, |
| 165 | ._dl_pagesize = EXEC_PAGESIZE, |
| 166 | ._dl_inhibit_cache = 0, |
| 167 | |
| 168 | /* Function pointers. */ |
| 169 | ._dl_debug_printf = _dl_debug_printf, |
| 170 | ._dl_catch_error = _dl_catch_error, |
| 171 | ._dl_signal_error = _dl_signal_error, |
| 172 | ._dl_mcount = _dl_mcount, |
| 173 | ._dl_lookup_symbol_x = _dl_lookup_symbol_x, |
| 174 | ._dl_check_caller = _dl_check_caller, |
| 175 | ._dl_open = _dl_open, |
| 176 | ._dl_close = _dl_close, |
| 177 | ._dl_tls_get_addr_soft = _dl_tls_get_addr_soft, |
| 178 | #ifdef HAVE_DL_DISCOVER_OSVERSION |
| 179 | ._dl_discover_osversion = _dl_discover_osversion |
| 180 | #endif |
| 181 | }; |
| 182 | /* If we would use strong_alias here the compiler would see a |
| 183 | non-hidden definition. This would undo the effect of the previous |
| 184 | declaration. So spell out was strong_alias does plus add the |
| 185 | visibility attribute. */ |
| 186 | extern struct rtld_global_ro _rtld_local_ro |
| 187 | __attribute__ ((alias ("_rtld_global_ro"), visibility ("hidden"))); |
| 188 | |
| 189 | |
| 190 | static void dl_main (const ElfW(Phdr) *phdr, ElfW(Word) phnum, |
| 191 | ElfW(Addr) *user_entry, ElfW(auxv_t) *auxv); |
| 192 | |
| 193 | /* These two variables cannot be moved into .data.rel.ro. */ |
| 194 | static struct libname_list _dl_rtld_libname; |
| 195 | static struct libname_list _dl_rtld_libname2; |
| 196 | |
| 197 | /* Variable for statistics. */ |
| 198 | #ifndef HP_TIMING_NONAVAIL |
| 199 | static hp_timing_t relocate_time; |
| 200 | static hp_timing_t load_time attribute_relro; |
| 201 | static hp_timing_t start_time attribute_relro; |
| 202 | #endif |
| 203 | |
| 204 | /* Additional definitions needed by TLS initialization. */ |
| 205 | #ifdef TLS_INIT_HELPER |
| 206 | TLS_INIT_HELPER |
| 207 | #endif |
| 208 | |
| 209 | /* Helper function for syscall implementation. */ |
| 210 | #ifdef DL_SYSINFO_IMPLEMENTATION |
| 211 | DL_SYSINFO_IMPLEMENTATION |
| 212 | #endif |
| 213 | |
| 214 | /* Before ld.so is relocated we must not access variables which need |
| 215 | relocations. This means variables which are exported. Variables |
| 216 | declared as static are fine. If we can mark a variable hidden this |
| 217 | is fine, too. The latter is important here. We can avoid setting |
| 218 | up a temporary link map for ld.so if we can mark _rtld_global as |
| 219 | hidden. */ |
| 220 | #ifdef PI_STATIC_AND_HIDDEN |
| 221 | # define DONT_USE_BOOTSTRAP_MAP 1 |
| 222 | #endif |
| 223 | |
| 224 | #ifdef DONT_USE_BOOTSTRAP_MAP |
| 225 | static ElfW(Addr) _dl_start_final (void *arg); |
| 226 | #else |
| 227 | struct dl_start_final_info |
| 228 | { |
| 229 | struct link_map l; |
| 230 | #if !defined HP_TIMING_NONAVAIL && HP_TIMING_INLINE |
| 231 | hp_timing_t start_time; |
| 232 | #endif |
| 233 | }; |
| 234 | static ElfW(Addr) _dl_start_final (void *arg, |
| 235 | struct dl_start_final_info *info); |
| 236 | #endif |
| 237 | |
| 238 | /* These defined magically in the linker script. */ |
| 239 | extern char _begin[] attribute_hidden; |
| 240 | extern char _etext[] attribute_hidden; |
| 241 | extern char _end[] attribute_hidden; |
| 242 | |
| 243 | |
| 244 | #ifdef RTLD_START |
| 245 | RTLD_START |
| 246 | #else |
| 247 | # error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START" |
| 248 | #endif |
| 249 | |
| 250 | /* This is the second half of _dl_start (below). It can be inlined safely |
| 251 | under DONT_USE_BOOTSTRAP_MAP, where it is careful not to make any GOT |
| 252 | references. When the tools don't permit us to avoid using a GOT entry |
| 253 | for _dl_rtld_global (no attribute_hidden support), we must make sure |
| 254 | this function is not inlined (see below). */ |
| 255 | |
| 256 | #ifdef DONT_USE_BOOTSTRAP_MAP |
| 257 | static inline ElfW(Addr) __attribute__ ((always_inline)) |
| 258 | _dl_start_final (void *arg) |
| 259 | #else |
| 260 | static ElfW(Addr) __attribute__ ((noinline)) |
| 261 | _dl_start_final (void *arg, struct dl_start_final_info *info) |
| 262 | #endif |
| 263 | { |
| 264 | ElfW(Addr) start_addr; |
| 265 | |
| 266 | if (HP_SMALL_TIMING_AVAIL) |
| 267 | { |
| 268 | /* If it hasn't happen yet record the startup time. */ |
| 269 | if (! HP_TIMING_INLINE) |
| 270 | HP_TIMING_NOW (start_time); |
| 271 | #if !defined DONT_USE_BOOTSTRAP_MAP && !defined HP_TIMING_NONAVAIL |
| 272 | else |
| 273 | start_time = info->start_time; |
| 274 | #endif |
| 275 | } |
| 276 | |
| 277 | /* Transfer data about ourselves to the permanent link_map structure. */ |
| 278 | #ifndef DONT_USE_BOOTSTRAP_MAP |
| 279 | GL(dl_rtld_map).l_addr = info->l.l_addr; |
| 280 | GL(dl_rtld_map).l_ld = info->l.l_ld; |
| 281 | memcpy (GL(dl_rtld_map).l_info, info->l.l_info, |
| 282 | sizeof GL(dl_rtld_map).l_info); |
| 283 | GL(dl_rtld_map).l_mach = info->l.l_mach; |
| 284 | GL(dl_rtld_map).l_relocated = 1; |
| 285 | #endif |
| 286 | _dl_setup_hash (&GL(dl_rtld_map)); |
| 287 | GL(dl_rtld_map).l_real = &GL(dl_rtld_map); |
| 288 | GL(dl_rtld_map).l_map_start = (ElfW(Addr)) _begin; |
| 289 | GL(dl_rtld_map).l_map_end = (ElfW(Addr)) _end; |
| 290 | GL(dl_rtld_map).l_text_end = (ElfW(Addr)) _etext; |
| 291 | /* Copy the TLS related data if necessary. */ |
| 292 | #ifndef DONT_USE_BOOTSTRAP_MAP |
| 293 | # if NO_TLS_OFFSET != 0 |
| 294 | GL(dl_rtld_map).l_tls_offset = NO_TLS_OFFSET; |
| 295 | # endif |
| 296 | #endif |
| 297 | |
| 298 | HP_TIMING_NOW (GL(dl_cpuclock_offset)); |
| 299 | |
| 300 | /* Initialize the stack end variable. */ |
| 301 | __libc_stack_end = __builtin_frame_address (0); |
| 302 | |
| 303 | /* Call the OS-dependent function to set up life so we can do things like |
| 304 | file access. It will call `dl_main' (below) to do all the real work |
| 305 | of the dynamic linker, and then unwind our frame and run the user |
| 306 | entry point on the same stack we entered on. */ |
| 307 | start_addr = _dl_sysdep_start (arg, &dl_main); |
| 308 | |
| 309 | #ifndef HP_TIMING_NONAVAIL |
| 310 | hp_timing_t rtld_total_time; |
| 311 | if (HP_SMALL_TIMING_AVAIL) |
| 312 | { |
| 313 | hp_timing_t end_time; |
| 314 | |
| 315 | /* Get the current time. */ |
| 316 | HP_TIMING_NOW (end_time); |
| 317 | |
| 318 | /* Compute the difference. */ |
| 319 | HP_TIMING_DIFF (rtld_total_time, start_time, end_time); |
| 320 | } |
| 321 | #endif |
| 322 | |
| 323 | if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_STATISTICS)) |
| 324 | { |
| 325 | #ifndef HP_TIMING_NONAVAIL |
| 326 | print_statistics (&rtld_total_time); |
| 327 | #else |
| 328 | print_statistics (NULL); |
| 329 | #endif |
| 330 | } |
| 331 | |
| 332 | return start_addr; |
| 333 | } |
| 334 | |
| 335 | static ElfW(Addr) __attribute_used__ internal_function |
| 336 | _dl_start (void *arg) |
| 337 | { |
| 338 | #ifdef DONT_USE_BOOTSTRAP_MAP |
| 339 | # define bootstrap_map GL(dl_rtld_map) |
| 340 | #else |
| 341 | struct dl_start_final_info info; |
| 342 | # define bootstrap_map info.l |
| 343 | #endif |
| 344 | |
| 345 | /* This #define produces dynamic linking inline functions for |
| 346 | bootstrap relocation instead of general-purpose relocation. |
| 347 | Since ld.so must not have any undefined symbols the result |
| 348 | is trivial: always the map of ld.so itself. */ |
| 349 | #define RTLD_BOOTSTRAP |
| 350 | #define RESOLVE_MAP(sym, version, flags) (&bootstrap_map) |
| 351 | #include "dynamic-link.h" |
| 352 | |
| 353 | if (HP_TIMING_INLINE && HP_SMALL_TIMING_AVAIL) |
| 354 | #ifdef DONT_USE_BOOTSTRAP_MAP |
| 355 | HP_TIMING_NOW (start_time); |
| 356 | #else |
| 357 | HP_TIMING_NOW (info.start_time); |
| 358 | #endif |
| 359 | |
| 360 | /* Partly clean the `bootstrap_map' structure up. Don't use |
| 361 | `memset' since it might not be built in or inlined and we cannot |
| 362 | make function calls at this point. Use '__builtin_memset' if we |
| 363 | know it is available. We do not have to clear the memory if we |
| 364 | do not have to use the temporary bootstrap_map. Global variables |
| 365 | are initialized to zero by default. */ |
| 366 | #ifndef DONT_USE_BOOTSTRAP_MAP |
| 367 | # ifdef HAVE_BUILTIN_MEMSET |
| 368 | __builtin_memset (bootstrap_map.l_info, '\0', sizeof (bootstrap_map.l_info)); |
| 369 | # else |
| 370 | for (size_t cnt = 0; |
| 371 | cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[0]); |
| 372 | ++cnt) |
| 373 | bootstrap_map.l_info[cnt] = 0; |
| 374 | # endif |
| 375 | #endif |
| 376 | |
| 377 | /* Figure out the run-time load address of the dynamic linker itself. */ |
| 378 | bootstrap_map.l_addr = elf_machine_load_address (); |
| 379 | |
| 380 | /* Read our own dynamic section and fill in the info array. */ |
| 381 | bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic (); |
| 382 | elf_get_dynamic_info (&bootstrap_map, NULL); |
| 383 | |
| 384 | #if NO_TLS_OFFSET != 0 |
| 385 | bootstrap_map.l_tls_offset = NO_TLS_OFFSET; |
| 386 | #endif |
| 387 | |
| 388 | #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC |
| 389 | ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info); |
| 390 | #endif |
| 391 | |
| 392 | if (bootstrap_map.l_addr || ! bootstrap_map.l_info[VALIDX(DT_GNU_PRELINKED)]) |
| 393 | { |
| 394 | /* Relocate ourselves so we can do normal function calls and |
| 395 | data access using the global offset table. */ |
| 396 | |
| 397 | ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0, 0); |
| 398 | } |
| 399 | bootstrap_map.l_relocated = 1; |
| 400 | |
| 401 | /* Please note that we don't allow profiling of this object and |
| 402 | therefore need not test whether we have to allocate the array |
| 403 | for the relocation results (as done in dl-reloc.c). */ |
| 404 | |
| 405 | /* Now life is sane; we can call functions and access global data. |
| 406 | Set up to use the operating system facilities, and find out from |
| 407 | the operating system's program loader where to find the program |
| 408 | header table in core. Put the rest of _dl_start into a separate |
| 409 | function, that way the compiler cannot put accesses to the GOT |
| 410 | before ELF_DYNAMIC_RELOCATE. */ |
| 411 | { |
| 412 | #ifdef DONT_USE_BOOTSTRAP_MAP |
| 413 | ElfW(Addr) entry = _dl_start_final (arg); |
| 414 | #else |
| 415 | ElfW(Addr) entry = _dl_start_final (arg, &info); |
| 416 | #endif |
| 417 | |
| 418 | #ifndef ELF_MACHINE_START_ADDRESS |
| 419 | # define ELF_MACHINE_START_ADDRESS(map, start) (start) |
| 420 | #endif |
| 421 | |
| 422 | return ELF_MACHINE_START_ADDRESS (GL(dl_ns)[LM_ID_BASE]._ns_loaded, entry); |
| 423 | } |
| 424 | } |
| 425 | |
| 426 | |
| 427 | |
| 428 | /* Now life is peachy; we can do all normal operations. |
| 429 | On to the real work. */ |
| 430 | |
| 431 | /* Some helper functions. */ |
| 432 | |
| 433 | /* Arguments to relocate_doit. */ |
| 434 | struct relocate_args |
| 435 | { |
| 436 | struct link_map *l; |
| 437 | int reloc_mode; |
| 438 | }; |
| 439 | |
| 440 | struct map_args |
| 441 | { |
| 442 | /* Argument to map_doit. */ |
| 443 | const char *str; |
| 444 | struct link_map *loader; |
| 445 | int mode; |
| 446 | /* Return value of map_doit. */ |
| 447 | struct link_map *map; |
| 448 | }; |
| 449 | |
| 450 | struct dlmopen_args |
| 451 | { |
| 452 | const char *fname; |
| 453 | struct link_map *map; |
| 454 | }; |
| 455 | |
| 456 | struct lookup_args |
| 457 | { |
| 458 | const char *name; |
| 459 | struct link_map *map; |
| 460 | void *result; |
| 461 | }; |
| 462 | |
| 463 | /* Arguments to version_check_doit. */ |
| 464 | struct version_check_args |
| 465 | { |
| 466 | int doexit; |
| 467 | int dotrace; |
| 468 | }; |
| 469 | |
| 470 | static void |
| 471 | relocate_doit (void *a) |
| 472 | { |
| 473 | struct relocate_args *args = (struct relocate_args *) a; |
| 474 | |
| 475 | _dl_relocate_object (args->l, args->l->l_scope, args->reloc_mode, 0); |
| 476 | } |
| 477 | |
| 478 | static void |
| 479 | map_doit (void *a) |
| 480 | { |
| 481 | struct map_args *args = (struct map_args *) a; |
| 482 | int type = (args->mode == __RTLD_OPENEXEC) ? lt_executable : lt_library; |
| 483 | args->map = _dl_map_object (args->loader, args->str, type, 0, |
| 484 | args->mode, LM_ID_BASE); |
| 485 | } |
| 486 | |
| 487 | static void |
| 488 | dlmopen_doit (void *a) |
| 489 | { |
| 490 | struct dlmopen_args *args = (struct dlmopen_args *) a; |
| 491 | args->map = _dl_open (args->fname, |
| 492 | (RTLD_LAZY | __RTLD_DLOPEN | __RTLD_AUDIT |
| 493 | | __RTLD_SECURE), |
| 494 | dl_main, LM_ID_NEWLM, _dl_argc, _dl_argv, |
| 495 | __environ); |
| 496 | } |
| 497 | |
| 498 | static void |
| 499 | lookup_doit (void *a) |
| 500 | { |
| 501 | struct lookup_args *args = (struct lookup_args *) a; |
| 502 | const ElfW(Sym) *ref = NULL; |
| 503 | args->result = NULL; |
| 504 | lookup_t l = _dl_lookup_symbol_x (args->name, args->map, &ref, |
| 505 | args->map->l_local_scope, NULL, 0, |
| 506 | DL_LOOKUP_RETURN_NEWEST, NULL); |
| 507 | if (ref != NULL) |
| 508 | args->result = DL_SYMBOL_ADDRESS (l, ref); |
| 509 | } |
| 510 | |
| 511 | static void |
| 512 | version_check_doit (void *a) |
| 513 | { |
| 514 | struct version_check_args *args = (struct version_check_args *) a; |
| 515 | if (_dl_check_all_versions (GL(dl_ns)[LM_ID_BASE]._ns_loaded, 1, |
| 516 | args->dotrace) && args->doexit) |
| 517 | /* We cannot start the application. Abort now. */ |
| 518 | _exit (1); |
| 519 | } |
| 520 | |
| 521 | |
| 522 | static inline struct link_map * |
| 523 | find_needed (const char *name) |
| 524 | { |
| 525 | struct r_scope_elem *scope = &GL(dl_ns)[LM_ID_BASE]._ns_loaded->l_searchlist; |
| 526 | unsigned int n = scope->r_nlist; |
| 527 | |
| 528 | while (n-- > 0) |
| 529 | if (_dl_name_match_p (name, scope->r_list[n])) |
| 530 | return scope->r_list[n]; |
| 531 | |
| 532 | /* Should never happen. */ |
| 533 | return NULL; |
| 534 | } |
| 535 | |
| 536 | static int |
| 537 | match_version (const char *string, struct link_map *map) |
| 538 | { |
| 539 | const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]); |
| 540 | ElfW(Verdef) *def; |
| 541 | |
| 542 | #define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF)) |
| 543 | if (map->l_info[VERDEFTAG] == NULL) |
| 544 | /* The file has no symbol versioning. */ |
| 545 | return 0; |
| 546 | |
| 547 | def = (ElfW(Verdef) *) ((char *) map->l_addr |
| 548 | + map->l_info[VERDEFTAG]->d_un.d_ptr); |
| 549 | while (1) |
| 550 | { |
| 551 | ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux); |
| 552 | |
| 553 | /* Compare the version strings. */ |
| 554 | if (strcmp (string, strtab + aux->vda_name) == 0) |
| 555 | /* Bingo! */ |
| 556 | return 1; |
| 557 | |
| 558 | /* If no more definitions we failed to find what we want. */ |
| 559 | if (def->vd_next == 0) |
| 560 | break; |
| 561 | |
| 562 | /* Next definition. */ |
| 563 | def = (ElfW(Verdef) *) ((char *) def + def->vd_next); |
| 564 | } |
| 565 | |
| 566 | return 0; |
| 567 | } |
| 568 | |
| 569 | static bool tls_init_tp_called; |
| 570 | |
| 571 | static void * |
| 572 | init_tls (void) |
| 573 | { |
| 574 | /* Number of elements in the static TLS block. */ |
| 575 | GL(dl_tls_static_nelem) = GL(dl_tls_max_dtv_idx); |
| 576 | |
| 577 | /* Do not do this twice. The audit interface might have required |
| 578 | the DTV interfaces to be set up early. */ |
| 579 | if (GL(dl_initial_dtv) != NULL) |
| 580 | return NULL; |
| 581 | |
| 582 | /* Allocate the array which contains the information about the |
| 583 | dtv slots. We allocate a few entries more than needed to |
| 584 | avoid the need for reallocation. */ |
| 585 | size_t nelem = GL(dl_tls_max_dtv_idx) + 1 + TLS_SLOTINFO_SURPLUS; |
| 586 | |
| 587 | /* Allocate. */ |
| 588 | GL(dl_tls_dtv_slotinfo_list) = (struct dtv_slotinfo_list *) |
| 589 | calloc (sizeof (struct dtv_slotinfo_list) |
| 590 | + nelem * sizeof (struct dtv_slotinfo), 1); |
| 591 | /* No need to check the return value. If memory allocation failed |
| 592 | the program would have been terminated. */ |
| 593 | |
| 594 | struct dtv_slotinfo *slotinfo = GL(dl_tls_dtv_slotinfo_list)->slotinfo; |
| 595 | GL(dl_tls_dtv_slotinfo_list)->len = nelem; |
| 596 | GL(dl_tls_dtv_slotinfo_list)->next = NULL; |
| 597 | |
| 598 | /* Fill in the information from the loaded modules. No namespace |
| 599 | but the base one can be filled at this time. */ |
| 600 | assert (GL(dl_ns)[LM_ID_BASE + 1]._ns_loaded == NULL); |
| 601 | int i = 0; |
| 602 | for (struct link_map *l = GL(dl_ns)[LM_ID_BASE]._ns_loaded; l != NULL; |
| 603 | l = l->l_next) |
| 604 | if (l->l_tls_blocksize != 0) |
| 605 | { |
| 606 | /* This is a module with TLS data. Store the map reference. |
| 607 | The generation counter is zero. */ |
| 608 | slotinfo[i].map = l; |
| 609 | /* slotinfo[i].gen = 0; */ |
| 610 | ++i; |
| 611 | } |
| 612 | assert (i == GL(dl_tls_max_dtv_idx)); |
| 613 | |
| 614 | /* Compute the TLS offsets for the various blocks. */ |
| 615 | _dl_determine_tlsoffset (); |
| 616 | |
| 617 | /* Construct the static TLS block and the dtv for the initial |
| 618 | thread. For some platforms this will include allocating memory |
| 619 | for the thread descriptor. The memory for the TLS block will |
| 620 | never be freed. It should be allocated accordingly. The dtv |
| 621 | array can be changed if dynamic loading requires it. */ |
| 622 | void *tcbp = _dl_allocate_tls_storage (); |
| 623 | if (tcbp == NULL) |
| 624 | _dl_fatal_printf ("\ |
| 625 | cannot allocate TLS data structures for initial thread"); |
| 626 | |
| 627 | /* Store for detection of the special case by __tls_get_addr |
| 628 | so it knows not to pass this dtv to the normal realloc. */ |
| 629 | GL(dl_initial_dtv) = GET_DTV (tcbp); |
| 630 | |
| 631 | /* And finally install it for the main thread. */ |
| 632 | const char *lossage = TLS_INIT_TP (tcbp); |
| 633 | if (__glibc_unlikely (lossage != NULL)) |
| 634 | _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage); |
| 635 | tls_init_tp_called = true; |
| 636 | |
| 637 | return tcbp; |
| 638 | } |
| 639 | |
| 640 | #ifdef _LIBC_REENTRANT |
| 641 | /* _dl_error_catch_tsd points to this for the single-threaded case. |
| 642 | It's reset by the thread library for multithreaded programs. */ |
| 643 | void ** __attribute__ ((const)) |
| 644 | _dl_initial_error_catch_tsd (void) |
| 645 | { |
| 646 | static void *data; |
| 647 | return &data; |
| 648 | } |
| 649 | #endif |
| 650 | |
| 651 | |
| 652 | static unsigned int |
| 653 | do_preload (const char *fname, struct link_map *main_map, const char *where) |
| 654 | { |
| 655 | const char *objname; |
| 656 | const char *err_str = NULL; |
| 657 | struct map_args args; |
| 658 | bool malloced; |
| 659 | |
| 660 | args.str = fname; |
| 661 | args.loader = main_map; |
| 662 | args.mode = __RTLD_SECURE; |
| 663 | |
| 664 | unsigned int old_nloaded = GL(dl_ns)[LM_ID_BASE]._ns_nloaded; |
| 665 | |
| 666 | (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit, &args); |
| 667 | if (__glibc_unlikely (err_str != NULL)) |
| 668 | { |
| 669 | _dl_error_printf ("\ |
| 670 | ERROR: ld.so: object '%s' from %s cannot be preloaded (%s): ignored.\n", |
| 671 | fname, where, err_str); |
| 672 | /* No need to call free, this is still before |
| 673 | the libc's malloc is used. */ |
| 674 | } |
| 675 | else if (GL(dl_ns)[LM_ID_BASE]._ns_nloaded != old_nloaded) |
| 676 | /* It is no duplicate. */ |
| 677 | return 1; |
| 678 | |
| 679 | /* Nothing loaded. */ |
| 680 | return 0; |
| 681 | } |
| 682 | |
| 683 | #if defined SHARED && defined _LIBC_REENTRANT \ |
| 684 | && defined __rtld_lock_default_lock_recursive |
| 685 | static void |
| 686 | rtld_lock_default_lock_recursive (void *lock) |
| 687 | { |
| 688 | __rtld_lock_default_lock_recursive (lock); |
| 689 | } |
| 690 | |
| 691 | static void |
| 692 | rtld_lock_default_unlock_recursive (void *lock) |
| 693 | { |
| 694 | __rtld_lock_default_unlock_recursive (lock); |
| 695 | } |
| 696 | #endif |
| 697 | |
| 698 | |
| 699 | static void |
| 700 | security_init (void) |
| 701 | { |
| 702 | /* Set up the stack checker's canary. */ |
| 703 | uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard (_dl_random); |
| 704 | #ifdef THREAD_SET_STACK_GUARD |
| 705 | THREAD_SET_STACK_GUARD (stack_chk_guard); |
| 706 | #else |
| 707 | __stack_chk_guard = stack_chk_guard; |
| 708 | #endif |
| 709 | |
| 710 | /* Set up the pointer guard as well, if necessary. */ |
| 711 | uintptr_t pointer_chk_guard |
| 712 | = _dl_setup_pointer_guard (_dl_random, stack_chk_guard); |
| 713 | #ifdef THREAD_SET_POINTER_GUARD |
| 714 | THREAD_SET_POINTER_GUARD (pointer_chk_guard); |
| 715 | #endif |
| 716 | __pointer_chk_guard_local = pointer_chk_guard; |
| 717 | |
| 718 | /* We do not need the _dl_random value anymore. The less |
| 719 | information we leave behind, the better, so clear the |
| 720 | variable. */ |
| 721 | _dl_random = NULL; |
| 722 | } |
| 723 | |
| 724 | #include "setup-vdso.h" |
| 725 | |
| 726 | /* The library search path. */ |
| 727 | static const char *library_path attribute_relro; |
| 728 | /* The list preloaded objects. */ |
| 729 | static const char *preloadlist attribute_relro; |
| 730 | /* Nonzero if information about versions has to be printed. */ |
| 731 | static int version_info attribute_relro; |
| 732 | |
| 733 | static void |
| 734 | dl_main (const ElfW(Phdr) *phdr, |
| 735 | ElfW(Word) phnum, |
| 736 | ElfW(Addr) *user_entry, |
| 737 | ElfW(auxv_t) *auxv) |
| 738 | { |
| 739 | const ElfW(Phdr) *ph; |
| 740 | enum mode mode; |
| 741 | struct link_map *main_map; |
| 742 | size_t file_size; |
| 743 | char *file; |
| 744 | bool has_interp = false; |
| 745 | unsigned int i; |
| 746 | bool prelinked = false; |
| 747 | bool rtld_is_main = false; |
| 748 | #ifndef HP_TIMING_NONAVAIL |
| 749 | hp_timing_t start; |
| 750 | hp_timing_t stop; |
| 751 | hp_timing_t diff; |
| 752 | #endif |
| 753 | void *tcbp = NULL; |
| 754 | |
| 755 | #ifdef _LIBC_REENTRANT |
| 756 | /* Explicit initialization since the reloc would just be more work. */ |
| 757 | GL(dl_error_catch_tsd) = &_dl_initial_error_catch_tsd; |
| 758 | #endif |
| 759 | |
| 760 | GL(dl_init_static_tls) = &_dl_nothread_init_static_tls; |
| 761 | |
| 762 | #if defined SHARED && defined _LIBC_REENTRANT \ |
| 763 | && defined __rtld_lock_default_lock_recursive |
| 764 | GL(dl_rtld_lock_recursive) = rtld_lock_default_lock_recursive; |
| 765 | GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive; |
| 766 | #endif |
| 767 | |
| 768 | /* The explicit initialization here is cheaper than processing the reloc |
| 769 | in the _rtld_local definition's initializer. */ |
| 770 | GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable; |
| 771 | |
| 772 | /* Process the environment variable which control the behaviour. */ |
| 773 | process_envvars (&mode); |
| 774 | |
| 775 | #ifndef HAVE_INLINED_SYSCALLS |
| 776 | /* Set up a flag which tells we are just starting. */ |
| 777 | _dl_starting_up = 1; |
| 778 | #endif |
| 779 | |
| 780 | if (*user_entry == (ElfW(Addr)) ENTRY_POINT) |
| 781 | { |
| 782 | /* Ho ho. We are not the program interpreter! We are the program |
| 783 | itself! This means someone ran ld.so as a command. Well, that |
| 784 | might be convenient to do sometimes. We support it by |
| 785 | interpreting the args like this: |
| 786 | |
| 787 | ld.so PROGRAM ARGS... |
| 788 | |
| 789 | The first argument is the name of a file containing an ELF |
| 790 | executable we will load and run with the following arguments. |
| 791 | To simplify life here, PROGRAM is searched for using the |
| 792 | normal rules for shared objects, rather than $PATH or anything |
| 793 | like that. We just load it and use its entry point; we don't |
| 794 | pay attention to its PT_INTERP command (we are the interpreter |
| 795 | ourselves). This is an easy way to test a new ld.so before |
| 796 | installing it. */ |
| 797 | rtld_is_main = true; |
| 798 | |
| 799 | /* Note the place where the dynamic linker actually came from. */ |
| 800 | GL(dl_rtld_map).l_name = rtld_progname; |
| 801 | |
| 802 | while (_dl_argc > 1) |
| 803 | if (! strcmp (_dl_argv[1], "--list")) |
| 804 | { |
| 805 | mode = list; |
| 806 | GLRO(dl_lazy) = -1; /* This means do no dependency analysis. */ |
| 807 | |
| 808 | ++_dl_skip_args; |
| 809 | --_dl_argc; |
| 810 | ++_dl_argv; |
| 811 | } |
| 812 | else if (! strcmp (_dl_argv[1], "--verify")) |
| 813 | { |
| 814 | mode = verify; |
| 815 | |
| 816 | ++_dl_skip_args; |
| 817 | --_dl_argc; |
| 818 | ++_dl_argv; |
| 819 | } |
| 820 | else if (! strcmp (_dl_argv[1], "--inhibit-cache")) |
| 821 | { |
| 822 | GLRO(dl_inhibit_cache) = 1; |
| 823 | ++_dl_skip_args; |
| 824 | --_dl_argc; |
| 825 | ++_dl_argv; |
| 826 | } |
| 827 | else if (! strcmp (_dl_argv[1], "--library-path") |
| 828 | && _dl_argc > 2) |
| 829 | { |
| 830 | library_path = _dl_argv[2]; |
| 831 | |
| 832 | _dl_skip_args += 2; |
| 833 | _dl_argc -= 2; |
| 834 | _dl_argv += 2; |
| 835 | } |
| 836 | else if (! strcmp (_dl_argv[1], "--inhibit-rpath") |
| 837 | && _dl_argc > 2) |
| 838 | { |
| 839 | GLRO(dl_inhibit_rpath) = _dl_argv[2]; |
| 840 | |
| 841 | _dl_skip_args += 2; |
| 842 | _dl_argc -= 2; |
| 843 | _dl_argv += 2; |
| 844 | } |
| 845 | else if (! strcmp (_dl_argv[1], "--audit") && _dl_argc > 2) |
| 846 | { |
| 847 | process_dl_audit (_dl_argv[2]); |
| 848 | |
| 849 | _dl_skip_args += 2; |
| 850 | _dl_argc -= 2; |
| 851 | _dl_argv += 2; |
| 852 | } |
| 853 | else |
| 854 | break; |
| 855 | |
| 856 | /* If we have no further argument the program was called incorrectly. |
| 857 | Grant the user some education. */ |
| 858 | if (_dl_argc < 2) |
| 859 | _dl_fatal_printf ("\ |
| 860 | Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\ |
| 861 | You have invoked `ld.so', the helper program for shared library executables.\n\ |
| 862 | This program usually lives in the file `/lib/ld.so', and special directives\n\ |
| 863 | in executable files using ELF shared libraries tell the system's program\n\ |
| 864 | loader to load the helper program from this file. This helper program loads\n\ |
| 865 | the shared libraries needed by the program executable, prepares the program\n\ |
| 866 | to run, and runs it. You may invoke this helper program directly from the\n\ |
| 867 | command line to load and run an ELF executable file; this is like executing\n\ |
| 868 | that file itself, but always uses this helper program from the file you\n\ |
| 869 | specified, instead of the helper program file specified in the executable\n\ |
| 870 | file you run. This is mostly of use for maintainers to test new versions\n\ |
| 871 | of this helper program; chances are you did not intend to run this program.\n\ |
| 872 | \n\ |
| 873 | --list list all dependencies and how they are resolved\n\ |
| 874 | --verify verify that given object really is a dynamically linked\n\ |
| 875 | object we can handle\n\ |
| 876 | --inhibit-cache Do not use " LD_SO_CACHE "\n\ |
| 877 | --library-path PATH use given PATH instead of content of the environment\n\ |
| 878 | variable LD_LIBRARY_PATH\n\ |
| 879 | --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\ |
| 880 | in LIST\n\ |
| 881 | --audit LIST use objects named in LIST as auditors\n"); |
| 882 | |
| 883 | ++_dl_skip_args; |
| 884 | --_dl_argc; |
| 885 | ++_dl_argv; |
| 886 | |
| 887 | /* The initialization of _dl_stack_flags done below assumes the |
| 888 | executable's PT_GNU_STACK may have been honored by the kernel, and |
| 889 | so a PT_GNU_STACK with PF_X set means the stack started out with |
| 890 | execute permission. However, this is not really true if the |
| 891 | dynamic linker is the executable the kernel loaded. For this |
| 892 | case, we must reinitialize _dl_stack_flags to match the dynamic |
| 893 | linker itself. If the dynamic linker was built with a |
| 894 | PT_GNU_STACK, then the kernel may have loaded us with a |
| 895 | nonexecutable stack that we will have to make executable when we |
| 896 | load the program below unless it has a PT_GNU_STACK indicating |
| 897 | nonexecutable stack is ok. */ |
| 898 | |
| 899 | for (ph = phdr; ph < &phdr[phnum]; ++ph) |
| 900 | if (ph->p_type == PT_GNU_STACK) |
| 901 | { |
| 902 | GL(dl_stack_flags) = ph->p_flags; |
| 903 | break; |
| 904 | } |
| 905 | |
| 906 | if (__builtin_expect (mode, normal) == verify) |
| 907 | { |
| 908 | const char *objname; |
| 909 | const char *err_str = NULL; |
| 910 | struct map_args args; |
| 911 | bool malloced; |
| 912 | |
| 913 | args.str = rtld_progname; |
| 914 | args.loader = NULL; |
| 915 | args.mode = __RTLD_OPENEXEC; |
| 916 | (void) _dl_catch_error (&objname, &err_str, &malloced, map_doit, |
| 917 | &args); |
| 918 | if (__glibc_unlikely (err_str != NULL)) |
| 919 | /* We don't free the returned string, the programs stops |
| 920 | anyway. */ |
| 921 | _exit (EXIT_FAILURE); |
| 922 | } |
| 923 | else |
| 924 | { |
| 925 | HP_TIMING_NOW (start); |
| 926 | _dl_map_object (NULL, rtld_progname, lt_executable, 0, |
| 927 | __RTLD_OPENEXEC, LM_ID_BASE); |
| 928 | HP_TIMING_NOW (stop); |
| 929 | |
| 930 | HP_TIMING_DIFF (load_time, start, stop); |
| 931 | } |
| 932 | |
| 933 | /* Now the map for the main executable is available. */ |
| 934 | main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded; |
| 935 | |
| 936 | if (__builtin_expect (mode, normal) == normal |
| 937 | && GL(dl_rtld_map).l_info[DT_SONAME] != NULL |
| 938 | && main_map->l_info[DT_SONAME] != NULL |
| 939 | && strcmp ((const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB]) |
| 940 | + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val, |
| 941 | (const char *) D_PTR (main_map, l_info[DT_STRTAB]) |
| 942 | + main_map->l_info[DT_SONAME]->d_un.d_val) == 0) |
| 943 | _dl_fatal_printf ("loader cannot load itself\n"); |
| 944 | |
| 945 | phdr = main_map->l_phdr; |
| 946 | phnum = main_map->l_phnum; |
| 947 | /* We overwrite here a pointer to a malloc()ed string. But since |
| 948 | the malloc() implementation used at this point is the dummy |
| 949 | implementations which has no real free() function it does not |
| 950 | makes sense to free the old string first. */ |
| 951 | main_map->l_name = (char *) ""; |
| 952 | *user_entry = main_map->l_entry; |
| 953 | |
| 954 | #ifdef HAVE_AUX_VECTOR |
| 955 | /* Adjust the on-stack auxiliary vector so that it looks like the |
| 956 | binary was executed directly. */ |
| 957 | for (ElfW(auxv_t) *av = auxv; av->a_type != AT_NULL; av++) |
| 958 | switch (av->a_type) |
| 959 | { |
| 960 | case AT_PHDR: |
| 961 | av->a_un.a_val = (uintptr_t) phdr; |
| 962 | break; |
| 963 | case AT_PHNUM: |
| 964 | av->a_un.a_val = phnum; |
| 965 | break; |
| 966 | case AT_ENTRY: |
| 967 | av->a_un.a_val = *user_entry; |
| 968 | break; |
| 969 | case AT_EXECFN: |
| 970 | av->a_un.a_val = (uintptr_t) _dl_argv[0]; |
| 971 | break; |
| 972 | } |
| 973 | #endif |
| 974 | } |
| 975 | else |
| 976 | { |
| 977 | /* Create a link_map for the executable itself. |
| 978 | This will be what dlopen on "" returns. */ |
| 979 | main_map = _dl_new_object ((char *) "", "", lt_executable, NULL, |
| 980 | __RTLD_OPENEXEC, LM_ID_BASE); |
| 981 | assert (main_map != NULL); |
| 982 | main_map->l_phdr = phdr; |
| 983 | main_map->l_phnum = phnum; |
| 984 | main_map->l_entry = *user_entry; |
| 985 | |
| 986 | /* Even though the link map is not yet fully initialized we can add |
| 987 | it to the map list since there are no possible users running yet. */ |
| 988 | _dl_add_to_namespace_list (main_map, LM_ID_BASE); |
| 989 | assert (main_map == GL(dl_ns)[LM_ID_BASE]._ns_loaded); |
| 990 | |
| 991 | /* At this point we are in a bit of trouble. We would have to |
| 992 | fill in the values for l_dev and l_ino. But in general we |
| 993 | do not know where the file is. We also do not handle AT_EXECFD |
| 994 | even if it would be passed up. |
| 995 | |
| 996 | We leave the values here defined to 0. This is normally no |
| 997 | problem as the program code itself is normally no shared |
| 998 | object and therefore cannot be loaded dynamically. Nothing |
| 999 | prevent the use of dynamic binaries and in these situations |
| 1000 | we might get problems. We might not be able to find out |
| 1001 | whether the object is already loaded. But since there is no |
| 1002 | easy way out and because the dynamic binary must also not |
| 1003 | have an SONAME we ignore this program for now. If it becomes |
| 1004 | a problem we can force people using SONAMEs. */ |
| 1005 | |
| 1006 | /* We delay initializing the path structure until we got the dynamic |
| 1007 | information for the program. */ |
| 1008 | } |
| 1009 | |
| 1010 | main_map->l_map_end = 0; |
| 1011 | main_map->l_text_end = 0; |
| 1012 | /* Perhaps the executable has no PT_LOAD header entries at all. */ |
| 1013 | main_map->l_map_start = ~0; |
| 1014 | /* And it was opened directly. */ |
| 1015 | ++main_map->l_direct_opencount; |
| 1016 | |
| 1017 | /* Scan the program header table for the dynamic section. */ |
| 1018 | for (ph = phdr; ph < &phdr[phnum]; ++ph) |
| 1019 | switch (ph->p_type) |
| 1020 | { |
| 1021 | case PT_PHDR: |
| 1022 | /* Find out the load address. */ |
| 1023 | main_map->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr; |
| 1024 | break; |
| 1025 | case PT_DYNAMIC: |
| 1026 | /* This tells us where to find the dynamic section, |
| 1027 | which tells us everything we need to do. */ |
| 1028 | main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr; |
| 1029 | break; |
| 1030 | case PT_INTERP: |
| 1031 | /* This "interpreter segment" was used by the program loader to |
| 1032 | find the program interpreter, which is this program itself, the |
| 1033 | dynamic linker. We note what name finds us, so that a future |
| 1034 | dlopen call or DT_NEEDED entry, for something that wants to link |
| 1035 | against the dynamic linker as a shared library, will know that |
| 1036 | the shared object is already loaded. */ |
| 1037 | _dl_rtld_libname.name = ((const char *) main_map->l_addr |
| 1038 | + ph->p_vaddr); |
| 1039 | /* _dl_rtld_libname.next = NULL; Already zero. */ |
| 1040 | GL(dl_rtld_map).l_libname = &_dl_rtld_libname; |
| 1041 | |
| 1042 | /* Ordinarilly, we would get additional names for the loader from |
| 1043 | our DT_SONAME. This can't happen if we were actually linked as |
| 1044 | a static executable (detect this case when we have no DYNAMIC). |
| 1045 | If so, assume the filename component of the interpreter path to |
| 1046 | be our SONAME, and add it to our name list. */ |
| 1047 | if (GL(dl_rtld_map).l_ld == NULL) |
| 1048 | { |
| 1049 | const char *p = NULL; |
| 1050 | const char *cp = _dl_rtld_libname.name; |
| 1051 | |
| 1052 | /* Find the filename part of the path. */ |
| 1053 | while (*cp != '\0') |
| 1054 | if (*cp++ == '/') |
| 1055 | p = cp; |
| 1056 | |
| 1057 | if (p != NULL) |
| 1058 | { |
| 1059 | _dl_rtld_libname2.name = p; |
| 1060 | /* _dl_rtld_libname2.next = NULL; Already zero. */ |
| 1061 | _dl_rtld_libname.next = &_dl_rtld_libname2; |
| 1062 | } |
| 1063 | } |
| 1064 | |
| 1065 | has_interp = true; |
| 1066 | break; |
| 1067 | case PT_LOAD: |
| 1068 | { |
| 1069 | ElfW(Addr) mapstart; |
| 1070 | ElfW(Addr) allocend; |
| 1071 | |
| 1072 | /* Remember where the main program starts in memory. */ |
| 1073 | mapstart = (main_map->l_addr |
| 1074 | + (ph->p_vaddr & ~(GLRO(dl_pagesize) - 1))); |
| 1075 | if (main_map->l_map_start > mapstart) |
| 1076 | main_map->l_map_start = mapstart; |
| 1077 | |
| 1078 | /* Also where it ends. */ |
| 1079 | allocend = main_map->l_addr + ph->p_vaddr + ph->p_memsz; |
| 1080 | if (main_map->l_map_end < allocend) |
| 1081 | main_map->l_map_end = allocend; |
| 1082 | if ((ph->p_flags & PF_X) && allocend > main_map->l_text_end) |
| 1083 | main_map->l_text_end = allocend; |
| 1084 | } |
| 1085 | break; |
| 1086 | |
| 1087 | case PT_TLS: |
| 1088 | if (ph->p_memsz > 0) |
| 1089 | { |
| 1090 | /* Note that in the case the dynamic linker we duplicate work |
| 1091 | here since we read the PT_TLS entry already in |
| 1092 | _dl_start_final. But the result is repeatable so do not |
| 1093 | check for this special but unimportant case. */ |
| 1094 | main_map->l_tls_blocksize = ph->p_memsz; |
| 1095 | main_map->l_tls_align = ph->p_align; |
| 1096 | if (ph->p_align == 0) |
| 1097 | main_map->l_tls_firstbyte_offset = 0; |
| 1098 | else |
| 1099 | main_map->l_tls_firstbyte_offset = (ph->p_vaddr |
| 1100 | & (ph->p_align - 1)); |
| 1101 | main_map->l_tls_initimage_size = ph->p_filesz; |
| 1102 | main_map->l_tls_initimage = (void *) ph->p_vaddr; |
| 1103 | |
| 1104 | /* This image gets the ID one. */ |
| 1105 | GL(dl_tls_max_dtv_idx) = main_map->l_tls_modid = 1; |
| 1106 | } |
| 1107 | break; |
| 1108 | |
| 1109 | case PT_GNU_STACK: |
| 1110 | GL(dl_stack_flags) = ph->p_flags; |
| 1111 | break; |
| 1112 | |
| 1113 | case PT_GNU_RELRO: |
| 1114 | main_map->l_relro_addr = ph->p_vaddr; |
| 1115 | main_map->l_relro_size = ph->p_memsz; |
| 1116 | break; |
| 1117 | } |
| 1118 | |
| 1119 | /* Adjust the address of the TLS initialization image in case |
| 1120 | the executable is actually an ET_DYN object. */ |
| 1121 | if (main_map->l_tls_initimage != NULL) |
| 1122 | main_map->l_tls_initimage |
| 1123 | = (char *) main_map->l_tls_initimage + main_map->l_addr; |
| 1124 | if (! main_map->l_map_end) |
| 1125 | main_map->l_map_end = ~0; |
| 1126 | if (! main_map->l_text_end) |
| 1127 | main_map->l_text_end = ~0; |
| 1128 | if (! GL(dl_rtld_map).l_libname && GL(dl_rtld_map).l_name) |
| 1129 | { |
| 1130 | /* We were invoked directly, so the program might not have a |
| 1131 | PT_INTERP. */ |
| 1132 | _dl_rtld_libname.name = GL(dl_rtld_map).l_name; |
| 1133 | /* _dl_rtld_libname.next = NULL; Already zero. */ |
| 1134 | GL(dl_rtld_map).l_libname = &_dl_rtld_libname; |
| 1135 | } |
| 1136 | else |
| 1137 | assert (GL(dl_rtld_map).l_libname); /* How else did we get here? */ |
| 1138 | |
| 1139 | /* If the current libname is different from the SONAME, add the |
| 1140 | latter as well. */ |
| 1141 | if (GL(dl_rtld_map).l_info[DT_SONAME] != NULL |
| 1142 | && strcmp (GL(dl_rtld_map).l_libname->name, |
| 1143 | (const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB]) |
| 1144 | + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val) != 0) |
| 1145 | { |
| 1146 | static struct libname_list newname; |
| 1147 | newname.name = ((char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB]) |
| 1148 | + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_ptr); |
| 1149 | newname.next = NULL; |
| 1150 | newname.dont_free = 1; |
| 1151 | |
| 1152 | assert (GL(dl_rtld_map).l_libname->next == NULL); |
| 1153 | GL(dl_rtld_map).l_libname->next = &newname; |
| 1154 | } |
| 1155 | /* The ld.so must be relocated since otherwise loading audit modules |
| 1156 | will fail since they reuse the very same ld.so. */ |
| 1157 | assert (GL(dl_rtld_map).l_relocated); |
| 1158 | |
| 1159 | if (! rtld_is_main) |
| 1160 | { |
| 1161 | /* Extract the contents of the dynamic section for easy access. */ |
| 1162 | elf_get_dynamic_info (main_map, NULL); |
| 1163 | /* Set up our cache of pointers into the hash table. */ |
| 1164 | _dl_setup_hash (main_map); |
| 1165 | } |
| 1166 | |
| 1167 | if (__builtin_expect (mode, normal) == verify) |
| 1168 | { |
| 1169 | /* We were called just to verify that this is a dynamic |
| 1170 | executable using us as the program interpreter. Exit with an |
| 1171 | error if we were not able to load the binary or no interpreter |
| 1172 | is specified (i.e., this is no dynamically linked binary. */ |
| 1173 | if (main_map->l_ld == NULL) |
| 1174 | _exit (1); |
| 1175 | |
| 1176 | /* We allow here some platform specific code. */ |
| 1177 | #ifdef DISTINGUISH_LIB_VERSIONS |
| 1178 | DISTINGUISH_LIB_VERSIONS; |
| 1179 | #endif |
| 1180 | _exit (has_interp ? 0 : 2); |
| 1181 | } |
| 1182 | |
| 1183 | struct link_map **first_preload = &GL(dl_rtld_map).l_next; |
| 1184 | /* Set up the data structures for the system-supplied DSO early, |
| 1185 | so they can influence _dl_init_paths. */ |
| 1186 | setup_vdso (main_map, &first_preload); |
| 1187 | |
| 1188 | #ifdef DL_SYSDEP_OSCHECK |
| 1189 | DL_SYSDEP_OSCHECK (_dl_fatal_printf); |
| 1190 | #endif |
| 1191 | |
| 1192 | /* Initialize the data structures for the search paths for shared |
| 1193 | objects. */ |
| 1194 | _dl_init_paths (library_path); |
| 1195 | |
| 1196 | /* Initialize _r_debug. */ |
| 1197 | struct r_debug *r = _dl_debug_initialize (GL(dl_rtld_map).l_addr, |
| 1198 | LM_ID_BASE); |
| 1199 | r->r_state = RT_CONSISTENT; |
| 1200 | |
| 1201 | /* Put the link_map for ourselves on the chain so it can be found by |
| 1202 | name. Note that at this point the global chain of link maps contains |
| 1203 | exactly one element, which is pointed to by dl_loaded. */ |
| 1204 | if (! GL(dl_rtld_map).l_name) |
| 1205 | /* If not invoked directly, the dynamic linker shared object file was |
| 1206 | found by the PT_INTERP name. */ |
| 1207 | GL(dl_rtld_map).l_name = (char *) GL(dl_rtld_map).l_libname->name; |
| 1208 | GL(dl_rtld_map).l_type = lt_library; |
| 1209 | main_map->l_next = &GL(dl_rtld_map); |
| 1210 | GL(dl_rtld_map).l_prev = main_map; |
| 1211 | ++GL(dl_ns)[LM_ID_BASE]._ns_nloaded; |
| 1212 | ++GL(dl_load_adds); |
| 1213 | |
| 1214 | /* If LD_USE_LOAD_BIAS env variable has not been seen, default |
| 1215 | to not using bias for non-prelinked PIEs and libraries |
| 1216 | and using it for executables or prelinked PIEs or libraries. */ |
| 1217 | if (GLRO(dl_use_load_bias) == (ElfW(Addr)) -2) |
| 1218 | GLRO(dl_use_load_bias) = main_map->l_addr == 0 ? -1 : 0; |
| 1219 | |
| 1220 | /* Set up the program header information for the dynamic linker |
| 1221 | itself. It is needed in the dl_iterate_phdr callbacks. */ |
| 1222 | const ElfW(Ehdr) *rtld_ehdr; |
| 1223 | |
| 1224 | /* Starting from binutils-2.23, the linker will define the magic symbol |
| 1225 | __ehdr_start to point to our own ELF header if it is visible in a |
| 1226 | segment that also includes the phdrs. If that's not available, we use |
| 1227 | the old method that assumes the beginning of the file is part of the |
| 1228 | lowest-addressed PT_LOAD segment. */ |
| 1229 | #ifdef HAVE_EHDR_START |
| 1230 | extern const ElfW(Ehdr) __ehdr_start __attribute__ ((visibility ("hidden"))); |
| 1231 | rtld_ehdr = &__ehdr_start; |
| 1232 | #else |
| 1233 | rtld_ehdr = (void *) GL(dl_rtld_map).l_map_start; |
| 1234 | #endif |
| 1235 | assert (rtld_ehdr->e_ehsize == sizeof *rtld_ehdr); |
| 1236 | assert (rtld_ehdr->e_phentsize == sizeof (ElfW(Phdr))); |
| 1237 | |
| 1238 | const ElfW(Phdr) *rtld_phdr = (const void *) rtld_ehdr + rtld_ehdr->e_phoff; |
| 1239 | |
| 1240 | GL(dl_rtld_map).l_phdr = rtld_phdr; |
| 1241 | GL(dl_rtld_map).l_phnum = rtld_ehdr->e_phnum; |
| 1242 | |
| 1243 | |
| 1244 | /* PT_GNU_RELRO is usually the last phdr. */ |
| 1245 | size_t cnt = rtld_ehdr->e_phnum; |
| 1246 | while (cnt-- > 0) |
| 1247 | if (rtld_phdr[cnt].p_type == PT_GNU_RELRO) |
| 1248 | { |
| 1249 | GL(dl_rtld_map).l_relro_addr = rtld_phdr[cnt].p_vaddr; |
| 1250 | GL(dl_rtld_map).l_relro_size = rtld_phdr[cnt].p_memsz; |
| 1251 | break; |
| 1252 | } |
| 1253 | |
| 1254 | /* Add the dynamic linker to the TLS list if it also uses TLS. */ |
| 1255 | if (GL(dl_rtld_map).l_tls_blocksize != 0) |
| 1256 | /* Assign a module ID. Do this before loading any audit modules. */ |
| 1257 | GL(dl_rtld_map).l_tls_modid = _dl_next_tls_modid (); |
| 1258 | |
| 1259 | /* If we have auditing DSOs to load, do it now. */ |
| 1260 | if (__glibc_unlikely (audit_list != NULL)) |
| 1261 | { |
| 1262 | /* Iterate over all entries in the list. The order is important. */ |
| 1263 | struct audit_ifaces *last_audit = NULL; |
| 1264 | struct audit_list *al = audit_list->next; |
| 1265 | |
| 1266 | /* Since we start using the auditing DSOs right away we need to |
| 1267 | initialize the data structures now. */ |
| 1268 | tcbp = init_tls (); |
| 1269 | |
| 1270 | /* Initialize security features. We need to do it this early |
| 1271 | since otherwise the constructors of the audit libraries will |
| 1272 | use different values (especially the pointer guard) and will |
| 1273 | fail later on. */ |
| 1274 | security_init (); |
| 1275 | |
| 1276 | do |
| 1277 | { |
| 1278 | int tls_idx = GL(dl_tls_max_dtv_idx); |
| 1279 | |
| 1280 | /* Now it is time to determine the layout of the static TLS |
| 1281 | block and allocate it for the initial thread. Note that we |
| 1282 | always allocate the static block, we never defer it even if |
| 1283 | no DF_STATIC_TLS bit is set. The reason is that we know |
| 1284 | glibc will use the static model. */ |
| 1285 | struct dlmopen_args dlmargs; |
| 1286 | dlmargs.fname = al->name; |
| 1287 | dlmargs.map = NULL; |
| 1288 | |
| 1289 | const char *objname; |
| 1290 | const char *err_str = NULL; |
| 1291 | bool malloced; |
| 1292 | (void) _dl_catch_error (&objname, &err_str, &malloced, dlmopen_doit, |
| 1293 | &dlmargs); |
| 1294 | if (__glibc_unlikely (err_str != NULL)) |
| 1295 | { |
| 1296 | not_loaded: |
| 1297 | _dl_error_printf ("\ |
| 1298 | ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n", |
| 1299 | al->name, err_str); |
| 1300 | if (malloced) |
| 1301 | free ((char *) err_str); |
| 1302 | } |
| 1303 | else |
| 1304 | { |
| 1305 | struct lookup_args largs; |
| 1306 | largs.name = "la_version"; |
| 1307 | largs.map = dlmargs.map; |
| 1308 | |
| 1309 | /* Check whether the interface version matches. */ |
| 1310 | (void) _dl_catch_error (&objname, &err_str, &malloced, |
| 1311 | lookup_doit, &largs); |
| 1312 | |
| 1313 | unsigned int (*laversion) (unsigned int); |
| 1314 | unsigned int lav; |
| 1315 | if (err_str == NULL |
| 1316 | && (laversion = largs.result) != NULL |
| 1317 | && (lav = laversion (LAV_CURRENT)) > 0 |
| 1318 | && lav <= LAV_CURRENT) |
| 1319 | { |
| 1320 | /* Allocate structure for the callback function pointers. |
| 1321 | This call can never fail. */ |
| 1322 | union |
| 1323 | { |
| 1324 | struct audit_ifaces ifaces; |
| 1325 | #define naudit_ifaces 8 |
| 1326 | void (*fptr[naudit_ifaces]) (void); |
| 1327 | } *newp = malloc (sizeof (*newp)); |
| 1328 | |
| 1329 | /* Names of the auditing interfaces. All in one |
| 1330 | long string. */ |
| 1331 | static const char audit_iface_names[] = |
| 1332 | "la_activity\0" |
| 1333 | "la_objsearch\0" |
| 1334 | "la_objopen\0" |
| 1335 | "la_preinit\0" |
| 1336 | #if __ELF_NATIVE_CLASS == 32 |
| 1337 | "la_symbind32\0" |
| 1338 | #elif __ELF_NATIVE_CLASS == 64 |
| 1339 | "la_symbind64\0" |
| 1340 | #else |
| 1341 | # error "__ELF_NATIVE_CLASS must be defined" |
| 1342 | #endif |
| 1343 | #define STRING(s) __STRING (s) |
| 1344 | "la_" STRING (ARCH_LA_PLTENTER) "\0" |
| 1345 | "la_" STRING (ARCH_LA_PLTEXIT) "\0" |
| 1346 | "la_objclose\0"; |
| 1347 | unsigned int cnt = 0; |
| 1348 | const char *cp = audit_iface_names; |
| 1349 | do |
| 1350 | { |
| 1351 | largs.name = cp; |
| 1352 | (void) _dl_catch_error (&objname, &err_str, &malloced, |
| 1353 | lookup_doit, &largs); |
| 1354 | |
| 1355 | /* Store the pointer. */ |
| 1356 | if (err_str == NULL && largs.result != NULL) |
| 1357 | { |
| 1358 | newp->fptr[cnt] = largs.result; |
| 1359 | |
| 1360 | /* The dynamic linker link map is statically |
| 1361 | allocated, initialize the data now. */ |
| 1362 | GL(dl_rtld_map).l_audit[cnt].cookie |
| 1363 | = (intptr_t) &GL(dl_rtld_map); |
| 1364 | } |
| 1365 | else |
| 1366 | newp->fptr[cnt] = NULL; |
| 1367 | ++cnt; |
| 1368 | |
| 1369 | cp = (char *) rawmemchr (cp, '\0') + 1; |
| 1370 | } |
| 1371 | while (*cp != '\0'); |
| 1372 | assert (cnt == naudit_ifaces); |
| 1373 | |
| 1374 | /* Now append the new auditing interface to the list. */ |
| 1375 | newp->ifaces.next = NULL; |
| 1376 | if (last_audit == NULL) |
| 1377 | last_audit = GLRO(dl_audit) = &newp->ifaces; |
| 1378 | else |
| 1379 | last_audit = last_audit->next = &newp->ifaces; |
| 1380 | ++GLRO(dl_naudit); |
| 1381 | |
| 1382 | /* Mark the DSO as being used for auditing. */ |
| 1383 | dlmargs.map->l_auditing = 1; |
| 1384 | } |
| 1385 | else |
| 1386 | { |
| 1387 | /* We cannot use the DSO, it does not have the |
| 1388 | appropriate interfaces or it expects something |
| 1389 | more recent. */ |
| 1390 | #ifndef NDEBUG |
| 1391 | Lmid_t ns = dlmargs.map->l_ns; |
| 1392 | #endif |
| 1393 | _dl_close (dlmargs.map); |
| 1394 | |
| 1395 | /* Make sure the namespace has been cleared entirely. */ |
| 1396 | assert (GL(dl_ns)[ns]._ns_loaded == NULL); |
| 1397 | assert (GL(dl_ns)[ns]._ns_nloaded == 0); |
| 1398 | |
| 1399 | GL(dl_tls_max_dtv_idx) = tls_idx; |
| 1400 | goto not_loaded; |
| 1401 | } |
| 1402 | } |
| 1403 | |
| 1404 | al = al->next; |
| 1405 | } |
| 1406 | while (al != audit_list->next); |
| 1407 | |
| 1408 | /* If we have any auditing modules, announce that we already |
| 1409 | have two objects loaded. */ |
| 1410 | if (__glibc_unlikely (GLRO(dl_naudit) > 0)) |
| 1411 | { |
| 1412 | struct link_map *ls[2] = { main_map, &GL(dl_rtld_map) }; |
| 1413 | |
| 1414 | for (unsigned int outer = 0; outer < 2; ++outer) |
| 1415 | { |
| 1416 | struct audit_ifaces *afct = GLRO(dl_audit); |
| 1417 | for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) |
| 1418 | { |
| 1419 | if (afct->objopen != NULL) |
| 1420 | { |
| 1421 | ls[outer]->l_audit[cnt].bindflags |
| 1422 | = afct->objopen (ls[outer], LM_ID_BASE, |
| 1423 | &ls[outer]->l_audit[cnt].cookie); |
| 1424 | |
| 1425 | ls[outer]->l_audit_any_plt |
| 1426 | |= ls[outer]->l_audit[cnt].bindflags != 0; |
| 1427 | } |
| 1428 | |
| 1429 | afct = afct->next; |
| 1430 | } |
| 1431 | } |
| 1432 | } |
| 1433 | } |
| 1434 | |
| 1435 | /* Keep track of the currently loaded modules to count how many |
| 1436 | non-audit modules which use TLS are loaded. */ |
| 1437 | size_t count_modids = _dl_count_modids (); |
| 1438 | |
| 1439 | /* Set up debugging before the debugger is notified for the first time. */ |
| 1440 | #ifdef ELF_MACHINE_DEBUG_SETUP |
| 1441 | /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */ |
| 1442 | ELF_MACHINE_DEBUG_SETUP (main_map, r); |
| 1443 | ELF_MACHINE_DEBUG_SETUP (&GL(dl_rtld_map), r); |
| 1444 | #else |
| 1445 | if (main_map->l_info[DT_DEBUG] != NULL) |
| 1446 | /* There is a DT_DEBUG entry in the dynamic section. Fill it in |
| 1447 | with the run-time address of the r_debug structure */ |
| 1448 | main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r; |
| 1449 | |
| 1450 | /* Fill in the pointer in the dynamic linker's own dynamic section, in |
| 1451 | case you run gdb on the dynamic linker directly. */ |
| 1452 | if (GL(dl_rtld_map).l_info[DT_DEBUG] != NULL) |
| 1453 | GL(dl_rtld_map).l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r; |
| 1454 | #endif |
| 1455 | |
| 1456 | /* We start adding objects. */ |
| 1457 | r->r_state = RT_ADD; |
| 1458 | _dl_debug_state (); |
| 1459 | LIBC_PROBE (init_start, 2, LM_ID_BASE, r); |
| 1460 | |
| 1461 | /* Auditing checkpoint: we are ready to signal that the initial map |
| 1462 | is being constructed. */ |
| 1463 | if (__glibc_unlikely (GLRO(dl_naudit) > 0)) |
| 1464 | { |
| 1465 | struct audit_ifaces *afct = GLRO(dl_audit); |
| 1466 | for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) |
| 1467 | { |
| 1468 | if (afct->activity != NULL) |
| 1469 | afct->activity (&main_map->l_audit[cnt].cookie, LA_ACT_ADD); |
| 1470 | |
| 1471 | afct = afct->next; |
| 1472 | } |
| 1473 | } |
| 1474 | |
| 1475 | /* We have two ways to specify objects to preload: via environment |
| 1476 | variable and via the file /etc/ld.so.preload. The latter can also |
| 1477 | be used when security is enabled. */ |
| 1478 | assert (*first_preload == NULL); |
| 1479 | struct link_map **preloads = NULL; |
| 1480 | unsigned int npreloads = 0; |
| 1481 | |
| 1482 | if (__glibc_unlikely (preloadlist != NULL)) |
| 1483 | { |
| 1484 | /* The LD_PRELOAD environment variable gives list of libraries |
| 1485 | separated by white space or colons that are loaded before the |
| 1486 | executable's dependencies and prepended to the global scope |
| 1487 | list. If the binary is running setuid all elements |
| 1488 | containing a '/' are ignored since it is insecure. */ |
| 1489 | char *list = strdupa (preloadlist); |
| 1490 | char *p; |
| 1491 | |
| 1492 | HP_TIMING_NOW (start); |
| 1493 | |
| 1494 | /* Prevent optimizing strsep. Speed is not important here. */ |
| 1495 | while ((p = (strsep) (&list, " :")) != NULL) |
| 1496 | if (p[0] != '\0' |
| 1497 | && (__builtin_expect (! __libc_enable_secure, 1) |
| 1498 | || strchr (p, '/') == NULL)) |
| 1499 | npreloads += do_preload (p, main_map, "LD_PRELOAD"); |
| 1500 | |
| 1501 | HP_TIMING_NOW (stop); |
| 1502 | HP_TIMING_DIFF (diff, start, stop); |
| 1503 | HP_TIMING_ACCUM_NT (load_time, diff); |
| 1504 | } |
| 1505 | |
| 1506 | /* There usually is no ld.so.preload file, it should only be used |
| 1507 | for emergencies and testing. So the open call etc should usually |
| 1508 | fail. Using access() on a non-existing file is faster than using |
| 1509 | open(). So we do this first. If it succeeds we do almost twice |
| 1510 | the work but this does not matter, since it is not for production |
| 1511 | use. */ |
| 1512 | static const char preload_file[] = "/etc/ld.so.preload"; |
| 1513 | if (__glibc_unlikely (__access (preload_file, R_OK) == 0)) |
| 1514 | { |
| 1515 | /* Read the contents of the file. */ |
| 1516 | file = _dl_sysdep_read_whole_file (preload_file, &file_size, |
| 1517 | PROT_READ | PROT_WRITE); |
| 1518 | if (__glibc_unlikely (file != MAP_FAILED)) |
| 1519 | { |
| 1520 | /* Parse the file. It contains names of libraries to be loaded, |
| 1521 | separated by white spaces or `:'. It may also contain |
| 1522 | comments introduced by `#'. */ |
| 1523 | char *problem; |
| 1524 | char *runp; |
| 1525 | size_t rest; |
| 1526 | |
| 1527 | /* Eliminate comments. */ |
| 1528 | runp = file; |
| 1529 | rest = file_size; |
| 1530 | while (rest > 0) |
| 1531 | { |
| 1532 | char *comment = memchr (runp, '#', rest); |
| 1533 | if (comment == NULL) |
| 1534 | break; |
| 1535 | |
| 1536 | rest -= comment - runp; |
| 1537 | do |
| 1538 | *comment = ' '; |
| 1539 | while (--rest > 0 && *++comment != '\n'); |
| 1540 | } |
| 1541 | |
| 1542 | /* We have one problematic case: if we have a name at the end of |
| 1543 | the file without a trailing terminating characters, we cannot |
| 1544 | place the \0. Handle the case separately. */ |
| 1545 | if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t' |
| 1546 | && file[file_size - 1] != '\n' && file[file_size - 1] != ':') |
| 1547 | { |
| 1548 | problem = &file[file_size]; |
| 1549 | while (problem > file && problem[-1] != ' ' |
| 1550 | && problem[-1] != '\t' |
| 1551 | && problem[-1] != '\n' && problem[-1] != ':') |
| 1552 | --problem; |
| 1553 | |
| 1554 | if (problem > file) |
| 1555 | problem[-1] = '\0'; |
| 1556 | } |
| 1557 | else |
| 1558 | { |
| 1559 | problem = NULL; |
| 1560 | file[file_size - 1] = '\0'; |
| 1561 | } |
| 1562 | |
| 1563 | HP_TIMING_NOW (start); |
| 1564 | |
| 1565 | if (file != problem) |
| 1566 | { |
| 1567 | char *p; |
| 1568 | runp = file; |
| 1569 | while ((p = strsep (&runp, ": \t\n")) != NULL) |
| 1570 | if (p[0] != '\0') |
| 1571 | npreloads += do_preload (p, main_map, preload_file); |
| 1572 | } |
| 1573 | |
| 1574 | if (problem != NULL) |
| 1575 | { |
| 1576 | char *p = strndupa (problem, file_size - (problem - file)); |
| 1577 | |
| 1578 | npreloads += do_preload (p, main_map, preload_file); |
| 1579 | } |
| 1580 | |
| 1581 | HP_TIMING_NOW (stop); |
| 1582 | HP_TIMING_DIFF (diff, start, stop); |
| 1583 | HP_TIMING_ACCUM_NT (load_time, diff); |
| 1584 | |
| 1585 | /* We don't need the file anymore. */ |
| 1586 | __munmap (file, file_size); |
| 1587 | } |
| 1588 | } |
| 1589 | |
| 1590 | if (__glibc_unlikely (*first_preload != NULL)) |
| 1591 | { |
| 1592 | /* Set up PRELOADS with a vector of the preloaded libraries. */ |
| 1593 | struct link_map *l = *first_preload; |
| 1594 | preloads = __alloca (npreloads * sizeof preloads[0]); |
| 1595 | i = 0; |
| 1596 | do |
| 1597 | { |
| 1598 | preloads[i++] = l; |
| 1599 | l = l->l_next; |
| 1600 | } while (l); |
| 1601 | assert (i == npreloads); |
| 1602 | } |
| 1603 | |
| 1604 | /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD |
| 1605 | specified some libraries to load, these are inserted before the actual |
| 1606 | dependencies in the executable's searchlist for symbol resolution. */ |
| 1607 | HP_TIMING_NOW (start); |
| 1608 | _dl_map_object_deps (main_map, preloads, npreloads, mode == trace, 0); |
| 1609 | HP_TIMING_NOW (stop); |
| 1610 | HP_TIMING_DIFF (diff, start, stop); |
| 1611 | HP_TIMING_ACCUM_NT (load_time, diff); |
| 1612 | |
| 1613 | /* Mark all objects as being in the global scope. */ |
| 1614 | for (i = main_map->l_searchlist.r_nlist; i > 0; ) |
| 1615 | main_map->l_searchlist.r_list[--i]->l_global = 1; |
| 1616 | |
| 1617 | /* Remove _dl_rtld_map from the chain. */ |
| 1618 | GL(dl_rtld_map).l_prev->l_next = GL(dl_rtld_map).l_next; |
| 1619 | if (GL(dl_rtld_map).l_next != NULL) |
| 1620 | GL(dl_rtld_map).l_next->l_prev = GL(dl_rtld_map).l_prev; |
| 1621 | |
| 1622 | for (i = 1; i < main_map->l_searchlist.r_nlist; ++i) |
| 1623 | if (main_map->l_searchlist.r_list[i] == &GL(dl_rtld_map)) |
| 1624 | break; |
| 1625 | |
| 1626 | bool rtld_multiple_ref = false; |
| 1627 | if (__glibc_likely (i < main_map->l_searchlist.r_nlist)) |
| 1628 | { |
| 1629 | /* Some DT_NEEDED entry referred to the interpreter object itself, so |
| 1630 | put it back in the list of visible objects. We insert it into the |
| 1631 | chain in symbol search order because gdb uses the chain's order as |
| 1632 | its symbol search order. */ |
| 1633 | rtld_multiple_ref = true; |
| 1634 | |
| 1635 | GL(dl_rtld_map).l_prev = main_map->l_searchlist.r_list[i - 1]; |
| 1636 | if (__builtin_expect (mode, normal) == normal) |
| 1637 | { |
| 1638 | GL(dl_rtld_map).l_next = (i + 1 < main_map->l_searchlist.r_nlist |
| 1639 | ? main_map->l_searchlist.r_list[i + 1] |
| 1640 | : NULL); |
| 1641 | #ifdef NEED_DL_SYSINFO_DSO |
| 1642 | if (GLRO(dl_sysinfo_map) != NULL |
| 1643 | && GL(dl_rtld_map).l_prev->l_next == GLRO(dl_sysinfo_map) |
| 1644 | && GL(dl_rtld_map).l_next != GLRO(dl_sysinfo_map)) |
| 1645 | GL(dl_rtld_map).l_prev = GLRO(dl_sysinfo_map); |
| 1646 | #endif |
| 1647 | } |
| 1648 | else |
| 1649 | /* In trace mode there might be an invisible object (which we |
| 1650 | could not find) after the previous one in the search list. |
| 1651 | In this case it doesn't matter much where we put the |
| 1652 | interpreter object, so we just initialize the list pointer so |
| 1653 | that the assertion below holds. */ |
| 1654 | GL(dl_rtld_map).l_next = GL(dl_rtld_map).l_prev->l_next; |
| 1655 | |
| 1656 | assert (GL(dl_rtld_map).l_prev->l_next == GL(dl_rtld_map).l_next); |
| 1657 | GL(dl_rtld_map).l_prev->l_next = &GL(dl_rtld_map); |
| 1658 | if (GL(dl_rtld_map).l_next != NULL) |
| 1659 | { |
| 1660 | assert (GL(dl_rtld_map).l_next->l_prev == GL(dl_rtld_map).l_prev); |
| 1661 | GL(dl_rtld_map).l_next->l_prev = &GL(dl_rtld_map); |
| 1662 | } |
| 1663 | } |
| 1664 | |
| 1665 | /* Now let us see whether all libraries are available in the |
| 1666 | versions we need. */ |
| 1667 | { |
| 1668 | struct version_check_args args; |
| 1669 | args.doexit = mode == normal; |
| 1670 | args.dotrace = mode == trace; |
| 1671 | _dl_receive_error (print_missing_version, version_check_doit, &args); |
| 1672 | } |
| 1673 | |
| 1674 | /* We do not initialize any of the TLS functionality unless any of the |
| 1675 | initial modules uses TLS. This makes dynamic loading of modules with |
| 1676 | TLS impossible, but to support it requires either eagerly doing setup |
| 1677 | now or lazily doing it later. Doing it now makes us incompatible with |
| 1678 | an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever |
| 1679 | used. Trying to do it lazily is too hairy to try when there could be |
| 1680 | multiple threads (from a non-TLS-using libpthread). */ |
| 1681 | bool was_tls_init_tp_called = tls_init_tp_called; |
| 1682 | if (tcbp == NULL) |
| 1683 | tcbp = init_tls (); |
| 1684 | |
| 1685 | if (__glibc_likely (audit_list == NULL)) |
| 1686 | /* Initialize security features. But only if we have not done it |
| 1687 | earlier. */ |
| 1688 | security_init (); |
| 1689 | |
| 1690 | if (__builtin_expect (mode, normal) != normal) |
| 1691 | { |
| 1692 | /* We were run just to list the shared libraries. It is |
| 1693 | important that we do this before real relocation, because the |
| 1694 | functions we call below for output may no longer work properly |
| 1695 | after relocation. */ |
| 1696 | struct link_map *l; |
| 1697 | |
| 1698 | if (GLRO(dl_debug_mask) & DL_DEBUG_PRELINK) |
| 1699 | { |
| 1700 | struct r_scope_elem *scope = &main_map->l_searchlist; |
| 1701 | |
| 1702 | for (i = 0; i < scope->r_nlist; i++) |
| 1703 | { |
| 1704 | l = scope->r_list [i]; |
| 1705 | if (l->l_faked) |
| 1706 | { |
| 1707 | _dl_printf ("\t%s => not found\n", l->l_libname->name); |
| 1708 | continue; |
| 1709 | } |
| 1710 | if (_dl_name_match_p (GLRO(dl_trace_prelink), l)) |
| 1711 | GLRO(dl_trace_prelink_map) = l; |
| 1712 | _dl_printf ("\t%s => %s (0x%0*Zx, 0x%0*Zx)", |
| 1713 | DSO_FILENAME (l->l_libname->name), |
| 1714 | DSO_FILENAME (l->l_name), |
| 1715 | (int) sizeof l->l_map_start * 2, |
| 1716 | (size_t) l->l_map_start, |
| 1717 | (int) sizeof l->l_addr * 2, |
| 1718 | (size_t) l->l_addr); |
| 1719 | |
| 1720 | if (l->l_tls_modid) |
| 1721 | _dl_printf (" TLS(0x%Zx, 0x%0*Zx)\n", l->l_tls_modid, |
| 1722 | (int) sizeof l->l_tls_offset * 2, |
| 1723 | (size_t) l->l_tls_offset); |
| 1724 | else |
| 1725 | _dl_printf ("\n"); |
| 1726 | } |
| 1727 | } |
| 1728 | else if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED) |
| 1729 | { |
| 1730 | /* Look through the dependencies of the main executable |
| 1731 | and determine which of them is not actually |
| 1732 | required. */ |
| 1733 | struct link_map *l = main_map; |
| 1734 | |
| 1735 | /* Relocate the main executable. */ |
| 1736 | struct relocate_args args = { .l = l, |
| 1737 | .reloc_mode = ((GLRO(dl_lazy) |
| 1738 | ? RTLD_LAZY : 0) |
| 1739 | | __RTLD_NOIFUNC) }; |
| 1740 | _dl_receive_error (print_unresolved, relocate_doit, &args); |
| 1741 | |
| 1742 | /* This loop depends on the dependencies of the executable to |
| 1743 | correspond in number and order to the DT_NEEDED entries. */ |
| 1744 | ElfW(Dyn) *dyn = main_map->l_ld; |
| 1745 | bool first = true; |
| 1746 | while (dyn->d_tag != DT_NULL) |
| 1747 | { |
| 1748 | if (dyn->d_tag == DT_NEEDED) |
| 1749 | { |
| 1750 | l = l->l_next; |
| 1751 | #ifdef NEED_DL_SYSINFO_DSO |
| 1752 | /* Skip the VDSO since it's not part of the list |
| 1753 | of objects we brought in via DT_NEEDED entries. */ |
| 1754 | if (l == GLRO(dl_sysinfo_map)) |
| 1755 | l = l->l_next; |
| 1756 | #endif |
| 1757 | if (!l->l_used) |
| 1758 | { |
| 1759 | if (first) |
| 1760 | { |
| 1761 | _dl_printf ("Unused direct dependencies:\n"); |
| 1762 | first = false; |
| 1763 | } |
| 1764 | |
| 1765 | _dl_printf ("\t%s\n", l->l_name); |
| 1766 | } |
| 1767 | } |
| 1768 | |
| 1769 | ++dyn; |
| 1770 | } |
| 1771 | |
| 1772 | _exit (first != true); |
| 1773 | } |
| 1774 | else if (! main_map->l_info[DT_NEEDED]) |
| 1775 | _dl_printf ("\tstatically linked\n"); |
| 1776 | else |
| 1777 | { |
| 1778 | for (l = main_map->l_next; l; l = l->l_next) |
| 1779 | if (l->l_faked) |
| 1780 | /* The library was not found. */ |
| 1781 | _dl_printf ("\t%s => not found\n", l->l_libname->name); |
| 1782 | else if (strcmp (l->l_libname->name, l->l_name) == 0) |
| 1783 | _dl_printf ("\t%s (0x%0*Zx)\n", l->l_libname->name, |
| 1784 | (int) sizeof l->l_map_start * 2, |
| 1785 | (size_t) l->l_map_start); |
| 1786 | else |
| 1787 | _dl_printf ("\t%s => %s (0x%0*Zx)\n", l->l_libname->name, |
| 1788 | l->l_name, (int) sizeof l->l_map_start * 2, |
| 1789 | (size_t) l->l_map_start); |
| 1790 | } |
| 1791 | |
| 1792 | if (__builtin_expect (mode, trace) != trace) |
| 1793 | for (i = 1; i < (unsigned int) _dl_argc; ++i) |
| 1794 | { |
| 1795 | const ElfW(Sym) *ref = NULL; |
| 1796 | ElfW(Addr) loadbase; |
| 1797 | lookup_t result; |
| 1798 | |
| 1799 | result = _dl_lookup_symbol_x (_dl_argv[i], main_map, |
| 1800 | &ref, main_map->l_scope, |
| 1801 | NULL, ELF_RTYPE_CLASS_PLT, |
| 1802 | DL_LOOKUP_ADD_DEPENDENCY, NULL); |
| 1803 | |
| 1804 | loadbase = LOOKUP_VALUE_ADDRESS (result); |
| 1805 | |
| 1806 | _dl_printf ("%s found at 0x%0*Zd in object at 0x%0*Zd\n", |
| 1807 | _dl_argv[i], |
| 1808 | (int) sizeof ref->st_value * 2, |
| 1809 | (size_t) ref->st_value, |
| 1810 | (int) sizeof loadbase * 2, (size_t) loadbase); |
| 1811 | } |
| 1812 | else |
| 1813 | { |
| 1814 | /* If LD_WARN is set, warn about undefined symbols. */ |
| 1815 | if (GLRO(dl_lazy) >= 0 && GLRO(dl_verbose)) |
| 1816 | { |
| 1817 | /* We have to do symbol dependency testing. */ |
| 1818 | struct relocate_args args; |
| 1819 | unsigned int i; |
| 1820 | |
| 1821 | args.reloc_mode = ((GLRO(dl_lazy) ? RTLD_LAZY : 0) |
| 1822 | | __RTLD_NOIFUNC); |
| 1823 | |
| 1824 | i = main_map->l_searchlist.r_nlist; |
| 1825 | while (i-- > 0) |
| 1826 | { |
| 1827 | struct link_map *l = main_map->l_initfini[i]; |
| 1828 | if (l != &GL(dl_rtld_map) && ! l->l_faked) |
| 1829 | { |
| 1830 | args.l = l; |
| 1831 | _dl_receive_error (print_unresolved, relocate_doit, |
| 1832 | &args); |
| 1833 | } |
| 1834 | } |
| 1835 | |
| 1836 | if ((GLRO(dl_debug_mask) & DL_DEBUG_PRELINK) |
| 1837 | && rtld_multiple_ref) |
| 1838 | { |
| 1839 | /* Mark the link map as not yet relocated again. */ |
| 1840 | GL(dl_rtld_map).l_relocated = 0; |
| 1841 | _dl_relocate_object (&GL(dl_rtld_map), |
| 1842 | main_map->l_scope, __RTLD_NOIFUNC, 0); |
| 1843 | } |
| 1844 | } |
| 1845 | #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED)) |
| 1846 | if (version_info) |
| 1847 | { |
| 1848 | /* Print more information. This means here, print information |
| 1849 | about the versions needed. */ |
| 1850 | int first = 1; |
| 1851 | struct link_map *map; |
| 1852 | |
| 1853 | for (map = main_map; map != NULL; map = map->l_next) |
| 1854 | { |
| 1855 | const char *strtab; |
| 1856 | ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG]; |
| 1857 | ElfW(Verneed) *ent; |
| 1858 | |
| 1859 | if (dyn == NULL) |
| 1860 | continue; |
| 1861 | |
| 1862 | strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]); |
| 1863 | ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr); |
| 1864 | |
| 1865 | if (first) |
| 1866 | { |
| 1867 | _dl_printf ("\n\tVersion information:\n"); |
| 1868 | first = 0; |
| 1869 | } |
| 1870 | |
| 1871 | _dl_printf ("\t%s:\n", DSO_FILENAME (map->l_name)); |
| 1872 | |
| 1873 | while (1) |
| 1874 | { |
| 1875 | ElfW(Vernaux) *aux; |
| 1876 | struct link_map *needed; |
| 1877 | |
| 1878 | needed = find_needed (strtab + ent->vn_file); |
| 1879 | aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux); |
| 1880 | |
| 1881 | while (1) |
| 1882 | { |
| 1883 | const char *fname = NULL; |
| 1884 | |
| 1885 | if (needed != NULL |
| 1886 | && match_version (strtab + aux->vna_name, |
| 1887 | needed)) |
| 1888 | fname = needed->l_name; |
| 1889 | |
| 1890 | _dl_printf ("\t\t%s (%s) %s=> %s\n", |
| 1891 | strtab + ent->vn_file, |
| 1892 | strtab + aux->vna_name, |
| 1893 | aux->vna_flags & VER_FLG_WEAK |
| 1894 | ? "[WEAK] " : "", |
| 1895 | fname ?: "not found"); |
| 1896 | |
| 1897 | if (aux->vna_next == 0) |
| 1898 | /* No more symbols. */ |
| 1899 | break; |
| 1900 | |
| 1901 | /* Next symbol. */ |
| 1902 | aux = (ElfW(Vernaux) *) ((char *) aux |
| 1903 | + aux->vna_next); |
| 1904 | } |
| 1905 | |
| 1906 | if (ent->vn_next == 0) |
| 1907 | /* No more dependencies. */ |
| 1908 | break; |
| 1909 | |
| 1910 | /* Next dependency. */ |
| 1911 | ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next); |
| 1912 | } |
| 1913 | } |
| 1914 | } |
| 1915 | } |
| 1916 | |
| 1917 | _exit (0); |
| 1918 | } |
| 1919 | |
| 1920 | if (main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)] |
| 1921 | && ! __builtin_expect (GLRO(dl_profile) != NULL, 0) |
| 1922 | && ! __builtin_expect (GLRO(dl_dynamic_weak), 0)) |
| 1923 | { |
| 1924 | ElfW(Lib) *liblist, *liblistend; |
| 1925 | struct link_map **r_list, **r_listend, *l; |
| 1926 | const char *strtab = (const void *) D_PTR (main_map, l_info[DT_STRTAB]); |
| 1927 | |
| 1928 | assert (main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)] != NULL); |
| 1929 | liblist = (ElfW(Lib) *) |
| 1930 | main_map->l_info[ADDRIDX (DT_GNU_LIBLIST)]->d_un.d_ptr; |
| 1931 | liblistend = (ElfW(Lib) *) |
| 1932 | ((char *) liblist + |
| 1933 | main_map->l_info[VALIDX (DT_GNU_LIBLISTSZ)]->d_un.d_val); |
| 1934 | r_list = main_map->l_searchlist.r_list; |
| 1935 | r_listend = r_list + main_map->l_searchlist.r_nlist; |
| 1936 | |
| 1937 | for (; r_list < r_listend && liblist < liblistend; r_list++) |
| 1938 | { |
| 1939 | l = *r_list; |
| 1940 | |
| 1941 | if (l == main_map) |
| 1942 | continue; |
| 1943 | |
| 1944 | /* If the library is not mapped where it should, fail. */ |
| 1945 | if (l->l_addr) |
| 1946 | break; |
| 1947 | |
| 1948 | /* Next, check if checksum matches. */ |
| 1949 | if (l->l_info [VALIDX(DT_CHECKSUM)] == NULL |
| 1950 | || l->l_info [VALIDX(DT_CHECKSUM)]->d_un.d_val |
| 1951 | != liblist->l_checksum) |
| 1952 | break; |
| 1953 | |
| 1954 | if (l->l_info [VALIDX(DT_GNU_PRELINKED)] == NULL |
| 1955 | || l->l_info [VALIDX(DT_GNU_PRELINKED)]->d_un.d_val |
| 1956 | != liblist->l_time_stamp) |
| 1957 | break; |
| 1958 | |
| 1959 | if (! _dl_name_match_p (strtab + liblist->l_name, l)) |
| 1960 | break; |
| 1961 | |
| 1962 | ++liblist; |
| 1963 | } |
| 1964 | |
| 1965 | |
| 1966 | if (r_list == r_listend && liblist == liblistend) |
| 1967 | prelinked = true; |
| 1968 | |
| 1969 | if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_LIBS)) |
| 1970 | _dl_debug_printf ("\nprelink checking: %s\n", |
| 1971 | prelinked ? "ok" : "failed"); |
| 1972 | } |
| 1973 | |
| 1974 | |
| 1975 | /* Now set up the variable which helps the assembler startup code. */ |
| 1976 | GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist = &main_map->l_searchlist; |
| 1977 | |
| 1978 | /* Save the information about the original global scope list since |
| 1979 | we need it in the memory handling later. */ |
| 1980 | GLRO(dl_initial_searchlist) = *GL(dl_ns)[LM_ID_BASE]._ns_main_searchlist; |
| 1981 | |
| 1982 | /* Remember the last search directory added at startup, now that |
| 1983 | malloc will no longer be the one from dl-minimal.c. */ |
| 1984 | GLRO(dl_init_all_dirs) = GL(dl_all_dirs); |
| 1985 | |
| 1986 | /* Print scope information. */ |
| 1987 | if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_SCOPES)) |
| 1988 | { |
| 1989 | _dl_debug_printf ("\nInitial object scopes\n"); |
| 1990 | |
| 1991 | for (struct link_map *l = main_map; l != NULL; l = l->l_next) |
| 1992 | _dl_show_scope (l, 0); |
| 1993 | } |
| 1994 | |
| 1995 | if (prelinked) |
| 1996 | { |
| 1997 | if (main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)] != NULL) |
| 1998 | { |
| 1999 | ElfW(Rela) *conflict, *conflictend; |
| 2000 | #ifndef HP_TIMING_NONAVAIL |
| 2001 | hp_timing_t start; |
| 2002 | hp_timing_t stop; |
| 2003 | #endif |
| 2004 | |
| 2005 | HP_TIMING_NOW (start); |
| 2006 | assert (main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)] != NULL); |
| 2007 | conflict = (ElfW(Rela) *) |
| 2008 | main_map->l_info [ADDRIDX (DT_GNU_CONFLICT)]->d_un.d_ptr; |
| 2009 | conflictend = (ElfW(Rela) *) |
| 2010 | ((char *) conflict |
| 2011 | + main_map->l_info [VALIDX (DT_GNU_CONFLICTSZ)]->d_un.d_val); |
| 2012 | _dl_resolve_conflicts (main_map, conflict, conflictend); |
| 2013 | HP_TIMING_NOW (stop); |
| 2014 | HP_TIMING_DIFF (relocate_time, start, stop); |
| 2015 | } |
| 2016 | |
| 2017 | |
| 2018 | /* Mark all the objects so we know they have been already relocated. */ |
| 2019 | for (struct link_map *l = main_map; l != NULL; l = l->l_next) |
| 2020 | { |
| 2021 | l->l_relocated = 1; |
| 2022 | if (l->l_relro_size) |
| 2023 | _dl_protect_relro (l); |
| 2024 | |
| 2025 | /* Add object to slot information data if necessasy. */ |
| 2026 | if (l->l_tls_blocksize != 0 && tls_init_tp_called) |
| 2027 | _dl_add_to_slotinfo (l); |
| 2028 | } |
| 2029 | } |
| 2030 | else |
| 2031 | { |
| 2032 | /* Now we have all the objects loaded. Relocate them all except for |
| 2033 | the dynamic linker itself. We do this in reverse order so that copy |
| 2034 | relocs of earlier objects overwrite the data written by later |
| 2035 | objects. We do not re-relocate the dynamic linker itself in this |
| 2036 | loop because that could result in the GOT entries for functions we |
| 2037 | call being changed, and that would break us. It is safe to relocate |
| 2038 | the dynamic linker out of order because it has no copy relocs (we |
| 2039 | know that because it is self-contained). */ |
| 2040 | |
| 2041 | int consider_profiling = GLRO(dl_profile) != NULL; |
| 2042 | #ifndef HP_TIMING_NONAVAIL |
| 2043 | hp_timing_t start; |
| 2044 | hp_timing_t stop; |
| 2045 | #endif |
| 2046 | |
| 2047 | /* If we are profiling we also must do lazy reloaction. */ |
| 2048 | GLRO(dl_lazy) |= consider_profiling; |
| 2049 | |
| 2050 | HP_TIMING_NOW (start); |
| 2051 | unsigned i = main_map->l_searchlist.r_nlist; |
| 2052 | while (i-- > 0) |
| 2053 | { |
| 2054 | struct link_map *l = main_map->l_initfini[i]; |
| 2055 | |
| 2056 | /* While we are at it, help the memory handling a bit. We have to |
| 2057 | mark some data structures as allocated with the fake malloc() |
| 2058 | implementation in ld.so. */ |
| 2059 | struct libname_list *lnp = l->l_libname->next; |
| 2060 | |
| 2061 | while (__builtin_expect (lnp != NULL, 0)) |
| 2062 | { |
| 2063 | lnp->dont_free = 1; |
| 2064 | lnp = lnp->next; |
| 2065 | } |
| 2066 | /* Also allocated with the fake malloc(). */ |
| 2067 | l->l_free_initfini = 0; |
| 2068 | |
| 2069 | if (l != &GL(dl_rtld_map)) |
| 2070 | _dl_relocate_object (l, l->l_scope, GLRO(dl_lazy) ? RTLD_LAZY : 0, |
| 2071 | consider_profiling); |
| 2072 | |
| 2073 | /* Add object to slot information data if necessasy. */ |
| 2074 | if (l->l_tls_blocksize != 0 && tls_init_tp_called) |
| 2075 | _dl_add_to_slotinfo (l); |
| 2076 | } |
| 2077 | HP_TIMING_NOW (stop); |
| 2078 | |
| 2079 | HP_TIMING_DIFF (relocate_time, start, stop); |
| 2080 | |
| 2081 | /* Now enable profiling if needed. Like the previous call, |
| 2082 | this has to go here because the calls it makes should use the |
| 2083 | rtld versions of the functions (particularly calloc()), but it |
| 2084 | needs to have _dl_profile_map set up by the relocator. */ |
| 2085 | if (__glibc_unlikely (GL(dl_profile_map) != NULL)) |
| 2086 | /* We must prepare the profiling. */ |
| 2087 | _dl_start_profile (); |
| 2088 | } |
| 2089 | |
| 2090 | if ((!was_tls_init_tp_called && GL(dl_tls_max_dtv_idx) > 0) |
| 2091 | || count_modids != _dl_count_modids ()) |
| 2092 | ++GL(dl_tls_generation); |
| 2093 | |
| 2094 | /* Now that we have completed relocation, the initializer data |
| 2095 | for the TLS blocks has its final values and we can copy them |
| 2096 | into the main thread's TLS area, which we allocated above. */ |
| 2097 | _dl_allocate_tls_init (tcbp); |
| 2098 | |
| 2099 | /* And finally install it for the main thread. */ |
| 2100 | if (! tls_init_tp_called) |
| 2101 | { |
| 2102 | const char *lossage = TLS_INIT_TP (tcbp); |
| 2103 | if (__glibc_unlikely (lossage != NULL)) |
| 2104 | _dl_fatal_printf ("cannot set up thread-local storage: %s\n", |
| 2105 | lossage); |
| 2106 | } |
| 2107 | |
| 2108 | /* Make sure no new search directories have been added. */ |
| 2109 | assert (GLRO(dl_init_all_dirs) == GL(dl_all_dirs)); |
| 2110 | |
| 2111 | if (! prelinked && rtld_multiple_ref) |
| 2112 | { |
| 2113 | /* There was an explicit ref to the dynamic linker as a shared lib. |
| 2114 | Re-relocate ourselves with user-controlled symbol definitions. |
| 2115 | |
| 2116 | We must do this after TLS initialization in case after this |
| 2117 | re-relocation, we might call a user-supplied function |
| 2118 | (e.g. calloc from _dl_relocate_object) that uses TLS data. */ |
| 2119 | |
| 2120 | #ifndef HP_TIMING_NONAVAIL |
| 2121 | hp_timing_t start; |
| 2122 | hp_timing_t stop; |
| 2123 | hp_timing_t add; |
| 2124 | #endif |
| 2125 | |
| 2126 | HP_TIMING_NOW (start); |
| 2127 | /* Mark the link map as not yet relocated again. */ |
| 2128 | GL(dl_rtld_map).l_relocated = 0; |
| 2129 | _dl_relocate_object (&GL(dl_rtld_map), main_map->l_scope, 0, 0); |
| 2130 | HP_TIMING_NOW (stop); |
| 2131 | HP_TIMING_DIFF (add, start, stop); |
| 2132 | HP_TIMING_ACCUM_NT (relocate_time, add); |
| 2133 | } |
| 2134 | |
| 2135 | /* Do any necessary cleanups for the startup OS interface code. |
| 2136 | We do these now so that no calls are made after rtld re-relocation |
| 2137 | which might be resolved to different functions than we expect. |
| 2138 | We cannot do this before relocating the other objects because |
| 2139 | _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */ |
| 2140 | _dl_sysdep_start_cleanup (); |
| 2141 | |
| 2142 | #ifdef SHARED |
| 2143 | /* Auditing checkpoint: we have added all objects. */ |
| 2144 | if (__glibc_unlikely (GLRO(dl_naudit) > 0)) |
| 2145 | { |
| 2146 | struct link_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded; |
| 2147 | /* Do not call the functions for any auditing object. */ |
| 2148 | if (head->l_auditing == 0) |
| 2149 | { |
| 2150 | struct audit_ifaces *afct = GLRO(dl_audit); |
| 2151 | for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt) |
| 2152 | { |
| 2153 | if (afct->activity != NULL) |
| 2154 | afct->activity (&head->l_audit[cnt].cookie, LA_ACT_CONSISTENT); |
| 2155 | |
| 2156 | afct = afct->next; |
| 2157 | } |
| 2158 | } |
| 2159 | } |
| 2160 | #endif |
| 2161 | |
| 2162 | /* Notify the debugger all new objects are now ready to go. We must re-get |
| 2163 | the address since by now the variable might be in another object. */ |
| 2164 | r = _dl_debug_initialize (0, LM_ID_BASE); |
| 2165 | r->r_state = RT_CONSISTENT; |
| 2166 | _dl_debug_state (); |
| 2167 | LIBC_PROBE (init_complete, 2, LM_ID_BASE, r); |
| 2168 | |
| 2169 | #if defined USE_LDCONFIG && !defined MAP_COPY |
| 2170 | /* We must munmap() the cache file. */ |
| 2171 | _dl_unload_cache (); |
| 2172 | #endif |
| 2173 | |
| 2174 | /* Once we return, _dl_sysdep_start will invoke |
| 2175 | the DT_INIT functions and then *USER_ENTRY. */ |
| 2176 | } |
| 2177 | |
| 2178 | /* This is a little helper function for resolving symbols while |
| 2179 | tracing the binary. */ |
| 2180 | static void |
| 2181 | print_unresolved (int errcode __attribute__ ((unused)), const char *objname, |
| 2182 | const char *errstring) |
| 2183 | { |
| 2184 | if (objname[0] == '\0') |
| 2185 | objname = RTLD_PROGNAME; |
| 2186 | _dl_error_printf ("%s (%s)\n", errstring, objname); |
| 2187 | } |
| 2188 | |
| 2189 | /* This is a little helper function for resolving symbols while |
| 2190 | tracing the binary. */ |
| 2191 | static void |
| 2192 | print_missing_version (int errcode __attribute__ ((unused)), |
| 2193 | const char *objname, const char *errstring) |
| 2194 | { |
| 2195 | _dl_error_printf ("%s: %s: %s\n", RTLD_PROGNAME, |
| 2196 | objname, errstring); |
| 2197 | } |
| 2198 | |
| 2199 | /* Nonzero if any of the debugging options is enabled. */ |
| 2200 | static int any_debug attribute_relro; |
| 2201 | |
| 2202 | /* Process the string given as the parameter which explains which debugging |
| 2203 | options are enabled. */ |
| 2204 | static void |
| 2205 | process_dl_debug (const char *dl_debug) |
| 2206 | { |
| 2207 | /* When adding new entries make sure that the maximal length of a name |
| 2208 | is correctly handled in the LD_DEBUG_HELP code below. */ |
| 2209 | static const struct |
| 2210 | { |
| 2211 | unsigned char len; |
| 2212 | const char name[10]; |
| 2213 | const char helptext[41]; |
| 2214 | unsigned short int mask; |
| 2215 | } debopts[] = |
| 2216 | { |
| 2217 | #define LEN_AND_STR(str) sizeof (str) - 1, str |
| 2218 | { LEN_AND_STR ("libs"), "display library search paths", |
| 2219 | DL_DEBUG_LIBS | DL_DEBUG_IMPCALLS }, |
| 2220 | { LEN_AND_STR ("reloc"), "display relocation processing", |
| 2221 | DL_DEBUG_RELOC | DL_DEBUG_IMPCALLS }, |
| 2222 | { LEN_AND_STR ("files"), "display progress for input file", |
| 2223 | DL_DEBUG_FILES | DL_DEBUG_IMPCALLS }, |
| 2224 | { LEN_AND_STR ("symbols"), "display symbol table processing", |
| 2225 | DL_DEBUG_SYMBOLS | DL_DEBUG_IMPCALLS }, |
| 2226 | { LEN_AND_STR ("bindings"), "display information about symbol binding", |
| 2227 | DL_DEBUG_BINDINGS | DL_DEBUG_IMPCALLS }, |
| 2228 | { LEN_AND_STR ("versions"), "display version dependencies", |
| 2229 | DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS }, |
| 2230 | { LEN_AND_STR ("scopes"), "display scope information", |
| 2231 | DL_DEBUG_SCOPES }, |
| 2232 | { LEN_AND_STR ("all"), "all previous options combined", |
| 2233 | DL_DEBUG_LIBS | DL_DEBUG_RELOC | DL_DEBUG_FILES | DL_DEBUG_SYMBOLS |
| 2234 | | DL_DEBUG_BINDINGS | DL_DEBUG_VERSIONS | DL_DEBUG_IMPCALLS |
| 2235 | | DL_DEBUG_SCOPES }, |
| 2236 | { LEN_AND_STR ("statistics"), "display relocation statistics", |
| 2237 | DL_DEBUG_STATISTICS }, |
| 2238 | { LEN_AND_STR ("unused"), "determined unused DSOs", |
| 2239 | DL_DEBUG_UNUSED }, |
| 2240 | { LEN_AND_STR ("help"), "display this help message and exit", |
| 2241 | DL_DEBUG_HELP }, |
| 2242 | }; |
| 2243 | #define ndebopts (sizeof (debopts) / sizeof (debopts[0])) |
| 2244 | |
| 2245 | /* Skip separating white spaces and commas. */ |
| 2246 | while (*dl_debug != '\0') |
| 2247 | { |
| 2248 | if (*dl_debug != ' ' && *dl_debug != ',' && *dl_debug != ':') |
| 2249 | { |
| 2250 | size_t cnt; |
| 2251 | size_t len = 1; |
| 2252 | |
| 2253 | while (dl_debug[len] != '\0' && dl_debug[len] != ' ' |
| 2254 | && dl_debug[len] != ',' && dl_debug[len] != ':') |
| 2255 | ++len; |
| 2256 | |
| 2257 | for (cnt = 0; cnt < ndebopts; ++cnt) |
| 2258 | if (debopts[cnt].len == len |
| 2259 | && memcmp (dl_debug, debopts[cnt].name, len) == 0) |
| 2260 | { |
| 2261 | GLRO(dl_debug_mask) |= debopts[cnt].mask; |
| 2262 | any_debug = 1; |
| 2263 | break; |
| 2264 | } |
| 2265 | |
| 2266 | if (cnt == ndebopts) |
| 2267 | { |
| 2268 | /* Display a warning and skip everything until next |
| 2269 | separator. */ |
| 2270 | char *copy = strndupa (dl_debug, len); |
| 2271 | _dl_error_printf ("\ |
| 2272 | warning: debug option `%s' unknown; try LD_DEBUG=help\n", copy); |
| 2273 | } |
| 2274 | |
| 2275 | dl_debug += len; |
| 2276 | continue; |
| 2277 | } |
| 2278 | |
| 2279 | ++dl_debug; |
| 2280 | } |
| 2281 | |
| 2282 | if (GLRO(dl_debug_mask) & DL_DEBUG_UNUSED) |
| 2283 | { |
| 2284 | /* In order to get an accurate picture of whether a particular |
| 2285 | DT_NEEDED entry is actually used we have to process both |
| 2286 | the PLT and non-PLT relocation entries. */ |
| 2287 | GLRO(dl_lazy) = 0; |
| 2288 | } |
| 2289 | |
| 2290 | if (GLRO(dl_debug_mask) & DL_DEBUG_HELP) |
| 2291 | { |
| 2292 | size_t cnt; |
| 2293 | |
| 2294 | _dl_printf ("\ |
| 2295 | Valid options for the LD_DEBUG environment variable are:\n\n"); |
| 2296 | |
| 2297 | for (cnt = 0; cnt < ndebopts; ++cnt) |
| 2298 | _dl_printf (" %.*s%s%s\n", debopts[cnt].len, debopts[cnt].name, |
| 2299 | " " + debopts[cnt].len - 3, |
| 2300 | debopts[cnt].helptext); |
| 2301 | |
| 2302 | _dl_printf ("\n\ |
| 2303 | To direct the debugging output into a file instead of standard output\n\ |
| 2304 | a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n"); |
| 2305 | _exit (0); |
| 2306 | } |
| 2307 | } |
| 2308 | |
| 2309 | static void |
| 2310 | process_dl_audit (char *str) |
| 2311 | { |
| 2312 | /* The parameter is a colon separated list of DSO names. */ |
| 2313 | char *p; |
| 2314 | |
| 2315 | while ((p = (strsep) (&str, ":")) != NULL) |
| 2316 | if (p[0] != '\0' |
| 2317 | && (__builtin_expect (! __libc_enable_secure, 1) |
| 2318 | || strchr (p, '/') == NULL)) |
| 2319 | { |
| 2320 | /* This is using the local malloc, not the system malloc. The |
| 2321 | memory can never be freed. */ |
| 2322 | struct audit_list *newp = malloc (sizeof (*newp)); |
| 2323 | newp->name = p; |
| 2324 | |
| 2325 | if (audit_list == NULL) |
| 2326 | audit_list = newp->next = newp; |
| 2327 | else |
| 2328 | { |
| 2329 | newp->next = audit_list->next; |
| 2330 | audit_list = audit_list->next = newp; |
| 2331 | } |
| 2332 | } |
| 2333 | } |
| 2334 | |
| 2335 | /* Process all environments variables the dynamic linker must recognize. |
| 2336 | Since all of them start with `LD_' we are a bit smarter while finding |
| 2337 | all the entries. */ |
| 2338 | extern char **_environ attribute_hidden; |
| 2339 | |
| 2340 | |
| 2341 | static void |
| 2342 | process_envvars (enum mode *modep) |
| 2343 | { |
| 2344 | char **runp = _environ; |
| 2345 | char *envline; |
| 2346 | enum mode mode = normal; |
| 2347 | char *debug_output = NULL; |
| 2348 | |
| 2349 | /* This is the default place for profiling data file. */ |
| 2350 | GLRO(dl_profile_output) |
| 2351 | = &"/var/tmp\0/var/profile"[__libc_enable_secure ? 9 : 0]; |
| 2352 | |
| 2353 | while ((envline = _dl_next_ld_env_entry (&runp)) != NULL) |
| 2354 | { |
| 2355 | size_t len = 0; |
| 2356 | |
| 2357 | while (envline[len] != '\0' && envline[len] != '=') |
| 2358 | ++len; |
| 2359 | |
| 2360 | if (envline[len] != '=') |
| 2361 | /* This is a "LD_" variable at the end of the string without |
| 2362 | a '=' character. Ignore it since otherwise we will access |
| 2363 | invalid memory below. */ |
| 2364 | continue; |
| 2365 | |
| 2366 | switch (len) |
| 2367 | { |
| 2368 | case 4: |
| 2369 | /* Warning level, verbose or not. */ |
| 2370 | if (memcmp (envline, "WARN", 4) == 0) |
| 2371 | GLRO(dl_verbose) = envline[5] != '\0'; |
| 2372 | break; |
| 2373 | |
| 2374 | case 5: |
| 2375 | /* Debugging of the dynamic linker? */ |
| 2376 | if (memcmp (envline, "DEBUG", 5) == 0) |
| 2377 | { |
| 2378 | process_dl_debug (&envline[6]); |
| 2379 | break; |
| 2380 | } |
| 2381 | if (memcmp (envline, "AUDIT", 5) == 0) |
| 2382 | process_dl_audit (&envline[6]); |
| 2383 | break; |
| 2384 | |
| 2385 | case 7: |
| 2386 | /* Print information about versions. */ |
| 2387 | if (memcmp (envline, "VERBOSE", 7) == 0) |
| 2388 | { |
| 2389 | version_info = envline[8] != '\0'; |
| 2390 | break; |
| 2391 | } |
| 2392 | |
| 2393 | /* List of objects to be preloaded. */ |
| 2394 | if (memcmp (envline, "PRELOAD", 7) == 0) |
| 2395 | { |
| 2396 | preloadlist = &envline[8]; |
| 2397 | break; |
| 2398 | } |
| 2399 | |
| 2400 | /* Which shared object shall be profiled. */ |
| 2401 | if (memcmp (envline, "PROFILE", 7) == 0 && envline[8] != '\0') |
| 2402 | GLRO(dl_profile) = &envline[8]; |
| 2403 | break; |
| 2404 | |
| 2405 | case 8: |
| 2406 | /* Do we bind early? */ |
| 2407 | if (memcmp (envline, "BIND_NOW", 8) == 0) |
| 2408 | { |
| 2409 | GLRO(dl_lazy) = envline[9] == '\0'; |
| 2410 | break; |
| 2411 | } |
| 2412 | if (memcmp (envline, "BIND_NOT", 8) == 0) |
| 2413 | GLRO(dl_bind_not) = envline[9] != '\0'; |
| 2414 | break; |
| 2415 | |
| 2416 | case 9: |
| 2417 | /* Test whether we want to see the content of the auxiliary |
| 2418 | array passed up from the kernel. */ |
| 2419 | if (!__libc_enable_secure |
| 2420 | && memcmp (envline, "SHOW_AUXV", 9) == 0) |
| 2421 | _dl_show_auxv (); |
| 2422 | break; |
| 2423 | |
| 2424 | case 10: |
| 2425 | /* Mask for the important hardware capabilities. */ |
| 2426 | if (memcmp (envline, "HWCAP_MASK", 10) == 0) |
| 2427 | GLRO(dl_hwcap_mask) = __strtoul_internal (&envline[11], NULL, |
| 2428 | 0, 0); |
| 2429 | break; |
| 2430 | |
| 2431 | case 11: |
| 2432 | /* Path where the binary is found. */ |
| 2433 | if (!__libc_enable_secure |
| 2434 | && memcmp (envline, "ORIGIN_PATH", 11) == 0) |
| 2435 | GLRO(dl_origin_path) = &envline[12]; |
| 2436 | break; |
| 2437 | |
| 2438 | case 12: |
| 2439 | /* The library search path. */ |
| 2440 | if (memcmp (envline, "LIBRARY_PATH", 12) == 0) |
| 2441 | { |
| 2442 | library_path = &envline[13]; |
| 2443 | break; |
| 2444 | } |
| 2445 | |
| 2446 | /* Where to place the profiling data file. */ |
| 2447 | if (memcmp (envline, "DEBUG_OUTPUT", 12) == 0) |
| 2448 | { |
| 2449 | debug_output = &envline[13]; |
| 2450 | break; |
| 2451 | } |
| 2452 | |
| 2453 | if (!__libc_enable_secure |
| 2454 | && memcmp (envline, "DYNAMIC_WEAK", 12) == 0) |
| 2455 | GLRO(dl_dynamic_weak) = 1; |
| 2456 | break; |
| 2457 | |
| 2458 | case 13: |
| 2459 | /* We might have some extra environment variable with length 13 |
| 2460 | to handle. */ |
| 2461 | #ifdef EXTRA_LD_ENVVARS_13 |
| 2462 | EXTRA_LD_ENVVARS_13 |
| 2463 | #endif |
| 2464 | if (!__libc_enable_secure |
| 2465 | && memcmp (envline, "USE_LOAD_BIAS", 13) == 0) |
| 2466 | { |
| 2467 | GLRO(dl_use_load_bias) = envline[14] == '1' ? -1 : 0; |
| 2468 | break; |
| 2469 | } |
| 2470 | break; |
| 2471 | |
| 2472 | case 14: |
| 2473 | /* Where to place the profiling data file. */ |
| 2474 | if (!__libc_enable_secure |
| 2475 | && memcmp (envline, "PROFILE_OUTPUT", 14) == 0 |
| 2476 | && envline[15] != '\0') |
| 2477 | GLRO(dl_profile_output) = &envline[15]; |
| 2478 | break; |
| 2479 | |
| 2480 | case 16: |
| 2481 | /* The mode of the dynamic linker can be set. */ |
| 2482 | if (memcmp (envline, "TRACE_PRELINKING", 16) == 0) |
| 2483 | { |
| 2484 | mode = trace; |
| 2485 | GLRO(dl_verbose) = 1; |
| 2486 | GLRO(dl_debug_mask) |= DL_DEBUG_PRELINK; |
| 2487 | GLRO(dl_trace_prelink) = &envline[17]; |
| 2488 | } |
| 2489 | break; |
| 2490 | |
| 2491 | case 20: |
| 2492 | /* The mode of the dynamic linker can be set. */ |
| 2493 | if (memcmp (envline, "TRACE_LOADED_OBJECTS", 20) == 0) |
| 2494 | mode = trace; |
| 2495 | break; |
| 2496 | |
| 2497 | /* We might have some extra environment variable to handle. This |
| 2498 | is tricky due to the pre-processing of the length of the name |
| 2499 | in the switch statement here. The code here assumes that added |
| 2500 | environment variables have a different length. */ |
| 2501 | #ifdef EXTRA_LD_ENVVARS |
| 2502 | EXTRA_LD_ENVVARS |
| 2503 | #endif |
| 2504 | } |
| 2505 | } |
| 2506 | |
| 2507 | /* The caller wants this information. */ |
| 2508 | *modep = mode; |
| 2509 | |
| 2510 | /* Extra security for SUID binaries. Remove all dangerous environment |
| 2511 | variables. */ |
| 2512 | if (__builtin_expect (__libc_enable_secure, 0)) |
| 2513 | { |
| 2514 | static const char unsecure_envvars[] = |
| 2515 | #ifdef EXTRA_UNSECURE_ENVVARS |
| 2516 | EXTRA_UNSECURE_ENVVARS |
| 2517 | #endif |
| 2518 | UNSECURE_ENVVARS; |
| 2519 | const char *nextp; |
| 2520 | |
| 2521 | nextp = unsecure_envvars; |
| 2522 | do |
| 2523 | { |
| 2524 | unsetenv (nextp); |
| 2525 | /* We could use rawmemchr but this need not be fast. */ |
| 2526 | nextp = (char *) (strchr) (nextp, '\0') + 1; |
| 2527 | } |
| 2528 | while (*nextp != '\0'); |
| 2529 | |
| 2530 | if (__access ("/etc/suid-debug", F_OK) != 0) |
| 2531 | { |
| 2532 | unsetenv ("MALLOC_CHECK_"); |
| 2533 | GLRO(dl_debug_mask) = 0; |
| 2534 | } |
| 2535 | |
| 2536 | if (mode != normal) |
| 2537 | _exit (5); |
| 2538 | } |
| 2539 | /* If we have to run the dynamic linker in debugging mode and the |
| 2540 | LD_DEBUG_OUTPUT environment variable is given, we write the debug |
| 2541 | messages to this file. */ |
| 2542 | else if (any_debug && debug_output != NULL) |
| 2543 | { |
| 2544 | #ifdef O_NOFOLLOW |
| 2545 | const int flags = O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW; |
| 2546 | #else |
| 2547 | const int flags = O_WRONLY | O_APPEND | O_CREAT; |
| 2548 | #endif |
| 2549 | size_t name_len = strlen (debug_output); |
| 2550 | char buf[name_len + 12]; |
| 2551 | char *startp; |
| 2552 | |
| 2553 | buf[name_len + 11] = '\0'; |
| 2554 | startp = _itoa (__getpid (), &buf[name_len + 11], 10, 0); |
| 2555 | *--startp = '.'; |
| 2556 | startp = memcpy (startp - name_len, debug_output, name_len); |
| 2557 | |
| 2558 | GLRO(dl_debug_fd) = __open (startp, flags, DEFFILEMODE); |
| 2559 | if (GLRO(dl_debug_fd) == -1) |
| 2560 | /* We use standard output if opening the file failed. */ |
| 2561 | GLRO(dl_debug_fd) = STDOUT_FILENO; |
| 2562 | } |
| 2563 | } |
| 2564 | |
| 2565 | |
| 2566 | /* Print the various times we collected. */ |
| 2567 | static void |
| 2568 | __attribute ((noinline)) |
| 2569 | print_statistics (hp_timing_t *rtld_total_timep) |
| 2570 | { |
| 2571 | #ifndef HP_TIMING_NONAVAIL |
| 2572 | char buf[200]; |
| 2573 | char *cp; |
| 2574 | char *wp; |
| 2575 | |
| 2576 | /* Total time rtld used. */ |
| 2577 | if (HP_SMALL_TIMING_AVAIL) |
| 2578 | { |
| 2579 | HP_TIMING_PRINT (buf, sizeof (buf), *rtld_total_timep); |
| 2580 | _dl_debug_printf ("\nruntime linker statistics:\n" |
| 2581 | " total startup time in dynamic loader: %s\n", buf); |
| 2582 | |
| 2583 | /* Print relocation statistics. */ |
| 2584 | char pbuf[30]; |
| 2585 | HP_TIMING_PRINT (buf, sizeof (buf), relocate_time); |
| 2586 | cp = _itoa ((1000ULL * relocate_time) / *rtld_total_timep, |
| 2587 | pbuf + sizeof (pbuf), 10, 0); |
| 2588 | wp = pbuf; |
| 2589 | switch (pbuf + sizeof (pbuf) - cp) |
| 2590 | { |
| 2591 | case 3: |
| 2592 | *wp++ = *cp++; |
| 2593 | case 2: |
| 2594 | *wp++ = *cp++; |
| 2595 | case 1: |
| 2596 | *wp++ = '.'; |
| 2597 | *wp++ = *cp++; |
| 2598 | } |
| 2599 | *wp = '\0'; |
| 2600 | _dl_debug_printf ("\ |
| 2601 | time needed for relocation: %s (%s%%)\n", buf, pbuf); |
| 2602 | } |
| 2603 | #endif |
| 2604 | |
| 2605 | unsigned long int num_relative_relocations = 0; |
| 2606 | for (Lmid_t ns = 0; ns < GL(dl_nns); ++ns) |
| 2607 | { |
| 2608 | if (GL(dl_ns)[ns]._ns_loaded == NULL) |
| 2609 | continue; |
| 2610 | |
| 2611 | struct r_scope_elem *scope = &GL(dl_ns)[ns]._ns_loaded->l_searchlist; |
| 2612 | |
| 2613 | for (unsigned int i = 0; i < scope->r_nlist; i++) |
| 2614 | { |
| 2615 | struct link_map *l = scope->r_list [i]; |
| 2616 | |
| 2617 | if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELCOUNT)]) |
| 2618 | num_relative_relocations |
| 2619 | += l->l_info[VERSYMIDX (DT_RELCOUNT)]->d_un.d_val; |
| 2620 | #ifndef ELF_MACHINE_REL_RELATIVE |
| 2621 | /* Relative relocations are processed on these architectures if |
| 2622 | library is loaded to different address than p_vaddr or |
| 2623 | if not prelinked. */ |
| 2624 | if ((l->l_addr != 0 || !l->l_info[VALIDX(DT_GNU_PRELINKED)]) |
| 2625 | && l->l_info[VERSYMIDX (DT_RELACOUNT)]) |
| 2626 | #else |
| 2627 | /* On e.g. IA-64 or Alpha, relative relocations are processed |
| 2628 | only if library is loaded to different address than p_vaddr. */ |
| 2629 | if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELACOUNT)]) |
| 2630 | #endif |
| 2631 | num_relative_relocations |
| 2632 | += l->l_info[VERSYMIDX (DT_RELACOUNT)]->d_un.d_val; |
| 2633 | } |
| 2634 | } |
| 2635 | |
| 2636 | _dl_debug_printf (" number of relocations: %lu\n" |
| 2637 | " number of relocations from cache: %lu\n" |
| 2638 | " number of relative relocations: %lu\n", |
| 2639 | GL(dl_num_relocations), |
| 2640 | GL(dl_num_cache_relocations), |
| 2641 | num_relative_relocations); |
| 2642 | |
| 2643 | #ifndef HP_TIMING_NONAVAIL |
| 2644 | /* Time spend while loading the object and the dependencies. */ |
| 2645 | if (HP_SMALL_TIMING_AVAIL) |
| 2646 | { |
| 2647 | char pbuf[30]; |
| 2648 | HP_TIMING_PRINT (buf, sizeof (buf), load_time); |
| 2649 | cp = _itoa ((1000ULL * load_time) / *rtld_total_timep, |
| 2650 | pbuf + sizeof (pbuf), 10, 0); |
| 2651 | wp = pbuf; |
| 2652 | switch (pbuf + sizeof (pbuf) - cp) |
| 2653 | { |
| 2654 | case 3: |
| 2655 | *wp++ = *cp++; |
| 2656 | case 2: |
| 2657 | *wp++ = *cp++; |
| 2658 | case 1: |
| 2659 | *wp++ = '.'; |
| 2660 | *wp++ = *cp++; |
| 2661 | } |
| 2662 | *wp = '\0'; |
| 2663 | _dl_debug_printf ("\ |
| 2664 | time needed to load objects: %s (%s%%)\n", |
| 2665 | buf, pbuf); |
| 2666 | } |
| 2667 | #endif |
| 2668 | } |