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1 | /* Run time dynamic linker. | |
2 | Copyright (C) 1995-1999, 2000 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 Library General Public License as | |
7 | published by the Free Software Foundation; either version 2 of the | |
8 | 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 | Library General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Library General Public | |
16 | License along with the GNU C Library; see the file COPYING.LIB. If not, | |
17 | write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
18 | Boston, MA 02111-1307, USA. */ | |
19 | ||
20 | #include <fcntl.h> | |
21 | #include <stdlib.h> | |
22 | #include <string.h> | |
23 | #include <unistd.h> | |
24 | #include <sys/mman.h> /* Check if MAP_ANON is defined. */ | |
25 | #include <ldsodefs.h> | |
26 | #include <stdio-common/_itoa.h> | |
27 | #include <entry.h> | |
28 | #include <fpu_control.h> | |
29 | #include <hp-timing.h> | |
30 | #include <bits/libc-lock.h> | |
31 | #include "dynamic-link.h" | |
32 | #include "dl-librecon.h" | |
33 | ||
34 | #include <assert.h> | |
35 | ||
36 | /* System-specific function to do initial startup for the dynamic linker. | |
37 | After this, file access calls and getenv must work. This is responsible | |
38 | for setting __libc_enable_secure if we need to be secure (e.g. setuid), | |
39 | and for setting _dl_argc and _dl_argv, and then calling _dl_main. */ | |
40 | extern ElfW(Addr) _dl_sysdep_start (void **start_argptr, | |
41 | void (*dl_main) (const ElfW(Phdr) *phdr, | |
42 | ElfW(Half) phent, | |
43 | ElfW(Addr) *user_entry)); | |
44 | extern void _dl_sysdep_start_cleanup (void); | |
45 | ||
46 | /* This function is used to unload the cache file if necessary. */ | |
47 | extern void _dl_unload_cache (void); | |
48 | ||
49 | /* System-dependent function to read a file's whole contents | |
50 | in the most convenient manner available. */ | |
51 | extern void *_dl_sysdep_read_whole_file (const char *filename, | |
52 | size_t *filesize_ptr, | |
53 | int mmap_prot); | |
54 | ||
55 | /* Protec SUID program against misuse of file descriptors. */ | |
56 | extern void __libc_check_standard_fds (void); | |
57 | ||
58 | /* Helper function to handle errors while resolving symbols. */ | |
59 | static void print_unresolved (int errcode, const char *objname, | |
60 | const char *errsting); | |
61 | ||
62 | /* Helper function to handle errors when a version is missing. */ | |
63 | static void print_missing_version (int errcode, const char *objname, | |
64 | const char *errsting); | |
65 | ||
66 | /* Print the various times we collected. */ | |
67 | static void print_statistics (void); | |
68 | ||
69 | /* This is a list of all the modes the dynamic loader can be in. */ | |
70 | enum mode { normal, list, verify, trace }; | |
71 | ||
72 | /* Process all environments variables the dynamic linker must recognize. | |
73 | Since all of them start with `LD_' we are a bit smarter while finding | |
74 | all the entries. */ | |
75 | static void process_envvars (enum mode *modep, int *lazyp); | |
76 | ||
77 | int _dl_argc; | |
78 | char **_dl_argv; | |
79 | unsigned int _dl_skip_args; /* Nonzero if we were run directly. */ | |
80 | int _dl_verbose; | |
81 | const char *_dl_platform; | |
82 | size_t _dl_platformlen; | |
83 | unsigned long _dl_hwcap; | |
84 | fpu_control_t _dl_fpu_control = _FPU_DEFAULT; | |
85 | struct r_search_path *_dl_search_paths; | |
86 | const char *_dl_profile; | |
87 | const char *_dl_profile_output; | |
88 | struct link_map *_dl_profile_map; | |
89 | int _dl_lazy; | |
90 | int _dl_dynamic_weak; | |
91 | int _dl_debug_libs; | |
92 | int _dl_debug_impcalls; | |
93 | int _dl_debug_bindings; | |
94 | int _dl_debug_symbols; | |
95 | int _dl_debug_versions; | |
96 | int _dl_debug_reloc; | |
97 | int _dl_debug_files; | |
98 | int _dl_debug_statistics; | |
99 | const char *_dl_inhibit_rpath; /* RPATH values which should be | |
100 | ignored. */ | |
101 | const char *_dl_origin_path; | |
102 | ||
103 | /* This is a pointer to the map for the main object and through it to | |
104 | all loaded objects. */ | |
105 | struct link_map *_dl_loaded; | |
106 | /* Pointer to the l_searchlist element of the link map of the main object. */ | |
107 | struct r_scope_elem *_dl_main_searchlist; | |
108 | /* Copy of the content of `_dl_main_searchlist'. */ | |
109 | struct r_scope_elem _dl_initial_searchlist; | |
110 | /* Array which is used when looking up in the global scope. */ | |
111 | struct r_scope_elem *_dl_global_scope[2]; | |
112 | ||
113 | /* During the program run we must not modify the global data of | |
114 | loaded shared object simultanously in two threads. Therefore we | |
115 | protect `_dl_open' and `_dl_close' in dl-close.c. | |
116 | ||
117 | This must be a recursive lock since the initializer function of | |
118 | the loaded object might as well require a call to this function. | |
119 | At this time it is not anymore a problem to modify the tables. */ | |
120 | __libc_lock_define_initialized_recursive (, _dl_load_lock) | |
121 | ||
122 | /* Set nonzero during loading and initialization of executable and | |
123 | libraries, cleared before the executable's entry point runs. This | |
124 | must not be initialized to nonzero, because the unused dynamic | |
125 | linker loaded in for libc.so's "ld.so.1" dep will provide the | |
126 | definition seen by libc.so's initializer; that value must be zero, | |
127 | and will be since that dynamic linker's _dl_start and dl_main will | |
128 | never be called. */ | |
129 | int _dl_starting_up; | |
130 | ||
131 | ||
132 | static void dl_main (const ElfW(Phdr) *phdr, | |
133 | ElfW(Half) phent, | |
134 | ElfW(Addr) *user_entry); | |
135 | ||
136 | struct link_map _dl_rtld_map; | |
137 | struct libname_list _dl_rtld_libname; | |
138 | struct libname_list _dl_rtld_libname2; | |
139 | ||
140 | /* Variable for statistics. */ | |
141 | #ifndef HP_TIMING_NONAVAIL | |
142 | static hp_timing_t rtld_total_time; | |
143 | static hp_timing_t relocate_time; | |
144 | static hp_timing_t load_time; | |
145 | #endif | |
146 | extern unsigned long int _dl_num_relocations; /* in dl-lookup.c */ | |
147 | ||
148 | static ElfW(Addr) _dl_start_final (void *arg, struct link_map *bootstrap_map_p, | |
149 | hp_timing_t start_time); | |
150 | ||
151 | #ifdef RTLD_START | |
152 | RTLD_START | |
153 | #else | |
154 | #error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START" | |
155 | #endif | |
156 | ||
157 | static ElfW(Addr) | |
158 | _dl_start (void *arg) | |
159 | { | |
160 | struct link_map bootstrap_map; | |
161 | hp_timing_t start_time; | |
162 | size_t cnt; | |
163 | ||
164 | /* This #define produces dynamic linking inline functions for | |
165 | bootstrap relocation instead of general-purpose relocation. */ | |
166 | #define RTLD_BOOTSTRAP | |
167 | #define RESOLVE_MAP(sym, version, flags) \ | |
168 | ((*(sym))->st_shndx == SHN_UNDEF ? 0 : &bootstrap_map) | |
169 | #define RESOLVE(sym, version, flags) \ | |
170 | ((*(sym))->st_shndx == SHN_UNDEF ? 0 : bootstrap_map.l_addr) | |
171 | #include "dynamic-link.h" | |
172 | ||
173 | if (HP_TIMING_INLINE && HP_TIMING_AVAIL) | |
174 | HP_TIMING_NOW (start_time); | |
175 | ||
176 | /* Partly clean the `bootstrap_map' structure up. Don't use `memset' | |
177 | since it might nor be built in or inlined and we cannot make function | |
178 | calls at this point. */ | |
179 | for (cnt = 0; | |
180 | cnt < sizeof (bootstrap_map.l_info) / sizeof (bootstrap_map.l_info[0]); | |
181 | ++cnt) | |
182 | bootstrap_map.l_info[cnt] = 0; | |
183 | ||
184 | /* Figure out the run-time load address of the dynamic linker itself. */ | |
185 | bootstrap_map.l_addr = elf_machine_load_address (); | |
186 | ||
187 | /* Read our own dynamic section and fill in the info array. */ | |
188 | bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic (); | |
189 | elf_get_dynamic_info (&bootstrap_map); | |
190 | ||
191 | #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC | |
192 | ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info); | |
193 | #endif | |
194 | ||
195 | /* Relocate ourselves so we can do normal function calls and | |
196 | data access using the global offset table. */ | |
197 | ||
198 | ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0); | |
199 | /* Please note that we don't allow profiling of this object and | |
200 | therefore need not test whether we have to allocate the array | |
201 | for the relocation results (as done in dl-reloc.c). */ | |
202 | ||
203 | /* Now life is sane; we can call functions and access global data. | |
204 | Set up to use the operating system facilities, and find out from | |
205 | the operating system's program loader where to find the program | |
206 | header table in core. Put the rest of _dl_start into a separate | |
207 | function, that way the compiler cannot put accesses to the GOT | |
208 | before ELF_DYNAMIC_RELOCATE. */ | |
209 | { | |
210 | ElfW(Addr) entry = _dl_start_final (arg, &bootstrap_map, start_time); | |
211 | ||
212 | #ifndef ELF_MACHINE_START_ADDRESS | |
213 | # define ELF_MACHINE_START_ADDRESS(map, start) (start) | |
214 | #endif | |
215 | ||
216 | return ELF_MACHINE_START_ADDRESS (_dl_loaded, entry); | |
217 | } | |
218 | } | |
219 | ||
220 | ||
221 | static ElfW(Addr) | |
222 | _dl_start_final (void *arg, struct link_map *bootstrap_map_p, | |
223 | hp_timing_t start_time) | |
224 | { | |
225 | /* The use of `alloca' here looks ridiculous but it helps. The goal | |
226 | is to avoid the function from being inlined. There is no official | |
227 | way to do this so we use this trick. gcc never inlines functions | |
228 | which use `alloca'. */ | |
229 | ElfW(Addr) *start_addr = alloca (sizeof (ElfW(Addr))); | |
230 | ||
231 | if (HP_TIMING_AVAIL) | |
232 | { | |
233 | /* If it hasn't happen yet record the startup time. */ | |
234 | if (! HP_TIMING_INLINE) | |
235 | HP_TIMING_NOW (start_time); | |
236 | ||
237 | /* Initialize the timing functions. */ | |
238 | HP_TIMING_DIFF_INIT (); | |
239 | } | |
240 | ||
241 | /* Transfer data about ourselves to the permanent link_map structure. */ | |
242 | _dl_rtld_map.l_addr = bootstrap_map_p->l_addr; | |
243 | _dl_rtld_map.l_ld = bootstrap_map_p->l_ld; | |
244 | _dl_rtld_map.l_opencount = 1; | |
245 | memcpy (_dl_rtld_map.l_info, bootstrap_map_p->l_info, | |
246 | sizeof _dl_rtld_map.l_info); | |
247 | _dl_setup_hash (&_dl_rtld_map); | |
248 | ||
249 | /* Don't bother trying to work out how ld.so is mapped in memory. */ | |
250 | _dl_rtld_map.l_map_start = ~0; | |
251 | _dl_rtld_map.l_map_end = ~0; | |
252 | ||
253 | /* Call the OS-dependent function to set up life so we can do things like | |
254 | file access. It will call `dl_main' (below) to do all the real work | |
255 | of the dynamic linker, and then unwind our frame and run the user | |
256 | entry point on the same stack we entered on. */ | |
257 | *start_addr = _dl_sysdep_start (arg, &dl_main); | |
258 | #ifndef HP_TIMING_NONAVAIL | |
259 | if (HP_TIMING_AVAIL) | |
260 | { | |
261 | hp_timing_t end_time; | |
262 | ||
263 | /* Get the current time. */ | |
264 | HP_TIMING_NOW (end_time); | |
265 | ||
266 | /* Compute the difference. */ | |
267 | HP_TIMING_DIFF (rtld_total_time, start_time, end_time); | |
268 | } | |
269 | #endif | |
270 | ||
271 | if (__builtin_expect (_dl_debug_statistics, 0)) | |
272 | print_statistics (); | |
273 | ||
274 | return *start_addr; | |
275 | } | |
276 | ||
277 | /* Now life is peachy; we can do all normal operations. | |
278 | On to the real work. */ | |
279 | ||
280 | void ENTRY_POINT (void); | |
281 | ||
282 | /* Some helper functions. */ | |
283 | ||
284 | /* Arguments to relocate_doit. */ | |
285 | struct relocate_args | |
286 | { | |
287 | struct link_map *l; | |
288 | int lazy; | |
289 | }; | |
290 | ||
291 | struct map_args | |
292 | { | |
293 | /* Argument to map_doit. */ | |
294 | char *str; | |
295 | /* Return value of map_doit. */ | |
296 | struct link_map *main_map; | |
297 | }; | |
298 | ||
299 | /* Arguments to version_check_doit. */ | |
300 | struct version_check_args | |
301 | { | |
302 | int doexit; | |
303 | int dotrace; | |
304 | }; | |
305 | ||
306 | static void | |
307 | relocate_doit (void *a) | |
308 | { | |
309 | struct relocate_args *args = (struct relocate_args *) a; | |
310 | ||
311 | _dl_relocate_object (args->l, args->l->l_scope, | |
312 | args->lazy, 0); | |
313 | } | |
314 | ||
315 | static void | |
316 | map_doit (void *a) | |
317 | { | |
318 | struct map_args *args = (struct map_args *) a; | |
319 | args->main_map = _dl_map_object (NULL, args->str, 0, lt_library, 0); | |
320 | } | |
321 | ||
322 | static void | |
323 | version_check_doit (void *a) | |
324 | { | |
325 | struct version_check_args *args = (struct version_check_args *) a; | |
326 | if (_dl_check_all_versions (_dl_loaded, 1, args->dotrace) && args->doexit) | |
327 | /* We cannot start the application. Abort now. */ | |
328 | _exit (1); | |
329 | } | |
330 | ||
331 | ||
332 | static inline struct link_map * | |
333 | find_needed (const char *name) | |
334 | { | |
335 | unsigned int n = _dl_loaded->l_searchlist.r_nlist; | |
336 | ||
337 | while (n-- > 0) | |
338 | if (_dl_name_match_p (name, _dl_loaded->l_searchlist.r_list[n])) | |
339 | return _dl_loaded->l_searchlist.r_list[n]; | |
340 | ||
341 | /* Should never happen. */ | |
342 | return NULL; | |
343 | } | |
344 | ||
345 | static int | |
346 | match_version (const char *string, struct link_map *map) | |
347 | { | |
348 | const char *strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]); | |
349 | ElfW(Verdef) *def; | |
350 | ||
351 | #define VERDEFTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERDEF)) | |
352 | if (map->l_info[VERDEFTAG] == NULL) | |
353 | /* The file has no symbol versioning. */ | |
354 | return 0; | |
355 | ||
356 | def = (ElfW(Verdef) *) ((char *) map->l_addr | |
357 | + map->l_info[VERDEFTAG]->d_un.d_ptr); | |
358 | while (1) | |
359 | { | |
360 | ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux); | |
361 | ||
362 | /* Compare the version strings. */ | |
363 | if (strcmp (string, strtab + aux->vda_name) == 0) | |
364 | /* Bingo! */ | |
365 | return 1; | |
366 | ||
367 | /* If no more definitions we failed to find what we want. */ | |
368 | if (def->vd_next == 0) | |
369 | break; | |
370 | ||
371 | /* Next definition. */ | |
372 | def = (ElfW(Verdef) *) ((char *) def + def->vd_next); | |
373 | } | |
374 | ||
375 | return 0; | |
376 | } | |
377 | ||
378 | static const char *library_path; /* The library search path. */ | |
379 | static const char *preloadlist; /* The list preloaded objects. */ | |
380 | static int version_info; /* Nonzero if information about | |
381 | versions has to be printed. */ | |
382 | ||
383 | static void | |
384 | dl_main (const ElfW(Phdr) *phdr, | |
385 | ElfW(Half) phent, | |
386 | ElfW(Addr) *user_entry) | |
387 | { | |
388 | const ElfW(Phdr) *ph; | |
389 | enum mode mode; | |
390 | struct link_map **preloads; | |
391 | unsigned int npreloads; | |
392 | size_t file_size; | |
393 | char *file; | |
394 | int has_interp = 0; | |
395 | unsigned int i; | |
396 | int rtld_is_main = 0; | |
397 | #ifndef HP_TIMING_NONAVAIL | |
398 | hp_timing_t start; | |
399 | hp_timing_t stop; | |
400 | hp_timing_t diff; | |
401 | #endif | |
402 | ||
403 | /* First thing, if this is a SUID program we make sure that FDs 0, | |
404 | 1, and 2 are allocated. If necessary we are doing it ourself. | |
405 | If it is not possible we stop the program. */ | |
406 | if (__builtin_expect (__libc_enable_secure, 0)) | |
407 | __libc_check_standard_fds (); | |
408 | ||
409 | /* Process the environment variable which control the behaviour. */ | |
410 | process_envvars (&mode, &_dl_lazy); | |
411 | ||
412 | /* Set up a flag which tells we are just starting. */ | |
413 | _dl_starting_up = 1; | |
414 | ||
415 | if (*user_entry == (ElfW(Addr)) &ENTRY_POINT) | |
416 | { | |
417 | /* Ho ho. We are not the program interpreter! We are the program | |
418 | itself! This means someone ran ld.so as a command. Well, that | |
419 | might be convenient to do sometimes. We support it by | |
420 | interpreting the args like this: | |
421 | ||
422 | ld.so PROGRAM ARGS... | |
423 | ||
424 | The first argument is the name of a file containing an ELF | |
425 | executable we will load and run with the following arguments. | |
426 | To simplify life here, PROGRAM is searched for using the | |
427 | normal rules for shared objects, rather than $PATH or anything | |
428 | like that. We just load it and use its entry point; we don't | |
429 | pay attention to its PT_INTERP command (we are the interpreter | |
430 | ourselves). This is an easy way to test a new ld.so before | |
431 | installing it. */ | |
432 | rtld_is_main = 1; | |
433 | ||
434 | /* Note the place where the dynamic linker actually came from. */ | |
435 | _dl_rtld_map.l_name = _dl_argv[0]; | |
436 | ||
437 | while (_dl_argc > 1) | |
438 | if (! strcmp (_dl_argv[1], "--list")) | |
439 | { | |
440 | mode = list; | |
441 | _dl_lazy = -1; /* This means do no dependency analysis. */ | |
442 | ||
443 | ++_dl_skip_args; | |
444 | --_dl_argc; | |
445 | ++_dl_argv; | |
446 | } | |
447 | else if (! strcmp (_dl_argv[1], "--verify")) | |
448 | { | |
449 | mode = verify; | |
450 | ||
451 | ++_dl_skip_args; | |
452 | --_dl_argc; | |
453 | ++_dl_argv; | |
454 | } | |
455 | else if (! strcmp (_dl_argv[1], "--library-path") && _dl_argc > 2) | |
456 | { | |
457 | library_path = _dl_argv[2]; | |
458 | ||
459 | _dl_skip_args += 2; | |
460 | _dl_argc -= 2; | |
461 | _dl_argv += 2; | |
462 | } | |
463 | else if (! strcmp (_dl_argv[1], "--inhibit-rpath") && _dl_argc > 2) | |
464 | { | |
465 | _dl_inhibit_rpath = _dl_argv[2]; | |
466 | ||
467 | _dl_skip_args += 2; | |
468 | _dl_argc -= 2; | |
469 | _dl_argv += 2; | |
470 | } | |
471 | else | |
472 | break; | |
473 | ||
474 | /* If we have no further argument the program was called incorrectly. | |
475 | Grant the user some education. */ | |
476 | if (_dl_argc < 2) | |
477 | _dl_sysdep_fatal ("\ | |
478 | Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\ | |
479 | You have invoked `ld.so', the helper program for shared library executables.\n\ | |
480 | This program usually lives in the file `/lib/ld.so', and special directives\n\ | |
481 | in executable files using ELF shared libraries tell the system's program\n\ | |
482 | loader to load the helper program from this file. This helper program loads\n\ | |
483 | the shared libraries needed by the program executable, prepares the program\n\ | |
484 | to run, and runs it. You may invoke this helper program directly from the\n\ | |
485 | command line to load and run an ELF executable file; this is like executing\n\ | |
486 | that file itself, but always uses this helper program from the file you\n\ | |
487 | specified, instead of the helper program file specified in the executable\n\ | |
488 | file you run. This is mostly of use for maintainers to test new versions\n\ | |
489 | of this helper program; chances are you did not intend to run this program.\n\ | |
490 | \n\ | |
491 | --list list all dependencies and how they are resolved\n\ | |
492 | --verify verify that given object really is a dynamically linked\n\ | |
493 | object we can handle\n\ | |
494 | --library-path PATH use given PATH instead of content of the environment\n\ | |
495 | variable LD_LIBRARY_PATH\n\ | |
496 | --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\ | |
497 | in LIST\n", | |
498 | NULL); | |
499 | ||
500 | ++_dl_skip_args; | |
501 | --_dl_argc; | |
502 | ++_dl_argv; | |
503 | ||
504 | /* Initialize the data structures for the search paths for shared | |
505 | objects. */ | |
506 | _dl_init_paths (library_path); | |
507 | ||
508 | if (__builtin_expect (mode, normal) == verify) | |
509 | { | |
510 | char *err_str = NULL; | |
511 | struct map_args args; | |
512 | ||
513 | args.str = _dl_argv[0]; | |
514 | (void) _dl_catch_error (&err_str, map_doit, &args); | |
515 | if (err_str != NULL) | |
516 | { | |
517 | free (err_str); | |
518 | _exit (EXIT_FAILURE); | |
519 | } | |
520 | } | |
521 | else | |
522 | { | |
523 | HP_TIMING_NOW (start); | |
524 | _dl_map_object (NULL, _dl_argv[0], 0, lt_library, 0); | |
525 | HP_TIMING_NOW (stop); | |
526 | ||
527 | HP_TIMING_DIFF (load_time, start, stop); | |
528 | } | |
529 | ||
530 | phdr = _dl_loaded->l_phdr; | |
531 | phent = _dl_loaded->l_phnum; | |
532 | /* We overwrite here a pointer to a malloc()ed string. But since | |
533 | the malloc() implementation used at this point is the dummy | |
534 | implementations which has no real free() function it does not | |
535 | makes sense to free the old string first. */ | |
536 | _dl_loaded->l_name = (char *) ""; | |
537 | *user_entry = _dl_loaded->l_entry; | |
538 | } | |
539 | else | |
540 | { | |
541 | /* Create a link_map for the executable itself. | |
542 | This will be what dlopen on "" returns. */ | |
543 | _dl_new_object ((char *) "", "", lt_executable, NULL); | |
544 | if (_dl_loaded == NULL) | |
545 | _dl_sysdep_fatal ("cannot allocate memory for link map\n", NULL); | |
546 | _dl_loaded->l_phdr = phdr; | |
547 | _dl_loaded->l_phnum = phent; | |
548 | _dl_loaded->l_entry = *user_entry; | |
549 | _dl_loaded->l_opencount = 1; | |
550 | ||
551 | /* At this point we are in a bit of trouble. We would have to | |
552 | fill in the values for l_dev and l_ino. But in general we | |
553 | do not know where the file is. We also do not handle AT_EXECFD | |
554 | even if it would be passed up. | |
555 | ||
556 | We leave the values here defined to 0. This is normally no | |
557 | problem as the program code itself is normally no shared | |
558 | object and therefore cannot be loaded dynamically. Nothing | |
559 | prevent the use of dynamic binaries and in these situations | |
560 | we might get problems. We might not be able to find out | |
561 | whether the object is already loaded. But since there is no | |
562 | easy way out and because the dynamic binary must also not | |
563 | have an SONAME we ignore this program for now. If it becomes | |
564 | a problem we can force people using SONAMEs. */ | |
565 | ||
566 | /* We delay initializing the path structure until we got the dynamic | |
567 | information for the program. */ | |
568 | } | |
569 | ||
570 | /* It is not safe to load stuff after the main program. */ | |
571 | _dl_loaded->l_map_end = ~0; | |
572 | /* Perhaps the executable has no PT_LOAD header entries at all. */ | |
573 | _dl_loaded->l_map_start = ~0; | |
574 | ||
575 | /* Scan the program header table for the dynamic section. */ | |
576 | for (ph = phdr; ph < &phdr[phent]; ++ph) | |
577 | switch (ph->p_type) | |
578 | { | |
579 | case PT_PHDR: | |
580 | /* Find out the load address. */ | |
581 | _dl_loaded->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr; | |
582 | break; | |
583 | case PT_DYNAMIC: | |
584 | /* This tells us where to find the dynamic section, | |
585 | which tells us everything we need to do. */ | |
586 | _dl_loaded->l_ld = (void *) _dl_loaded->l_addr + ph->p_vaddr; | |
587 | break; | |
588 | case PT_INTERP: | |
589 | /* This "interpreter segment" was used by the program loader to | |
590 | find the program interpreter, which is this program itself, the | |
591 | dynamic linker. We note what name finds us, so that a future | |
592 | dlopen call or DT_NEEDED entry, for something that wants to link | |
593 | against the dynamic linker as a shared library, will know that | |
594 | the shared object is already loaded. */ | |
595 | _dl_rtld_libname.name = ((const char *) _dl_loaded->l_addr | |
596 | + ph->p_vaddr); | |
597 | _dl_rtld_libname.next = NULL; | |
598 | _dl_rtld_map.l_libname = &_dl_rtld_libname; | |
599 | ||
600 | /* Ordinarilly, we would get additional names for the loader from | |
601 | our DT_SONAME. This can't happen if we were actually linked as | |
602 | a static executable (detect this case when we have no DYNAMIC). | |
603 | If so, assume the filename component of the interpreter path to | |
604 | be our SONAME, and add it to our name list. */ | |
605 | if (_dl_rtld_map.l_ld == NULL) | |
606 | { | |
607 | char *p = strrchr (_dl_rtld_libname.name, '/'); | |
608 | if (p) | |
609 | { | |
610 | _dl_rtld_libname2.name = p+1; | |
611 | _dl_rtld_libname2.next = NULL; | |
612 | _dl_rtld_libname.next = &_dl_rtld_libname2; | |
613 | } | |
614 | } | |
615 | ||
616 | has_interp = 1; | |
617 | break; | |
618 | case PT_LOAD: | |
619 | /* Remember where the main program starts in memory. */ | |
620 | { | |
621 | ElfW(Addr) mapstart; | |
622 | mapstart = _dl_loaded->l_addr + (ph->p_vaddr & ~(ph->p_align - 1)); | |
623 | if (_dl_loaded->l_map_start > mapstart) | |
624 | _dl_loaded->l_map_start = mapstart; | |
625 | } | |
626 | break; | |
627 | } | |
628 | if (! _dl_rtld_map.l_libname && _dl_rtld_map.l_name) | |
629 | { | |
630 | /* We were invoked directly, so the program might not have a | |
631 | PT_INTERP. */ | |
632 | _dl_rtld_libname.name = _dl_rtld_map.l_name; | |
633 | _dl_rtld_libname.next = NULL; | |
634 | _dl_rtld_map.l_libname = &_dl_rtld_libname; | |
635 | } | |
636 | else | |
637 | assert (_dl_rtld_map.l_libname); /* How else did we get here? */ | |
638 | ||
639 | if (! rtld_is_main) | |
640 | { | |
641 | /* Extract the contents of the dynamic section for easy access. */ | |
642 | elf_get_dynamic_info (_dl_loaded); | |
643 | if (_dl_loaded->l_info[DT_HASH]) | |
644 | /* Set up our cache of pointers into the hash table. */ | |
645 | _dl_setup_hash (_dl_loaded); | |
646 | } | |
647 | ||
648 | if (__builtin_expect (mode, normal) == verify) | |
649 | { | |
650 | /* We were called just to verify that this is a dynamic | |
651 | executable using us as the program interpreter. Exit with an | |
652 | error if we were not able to load the binary or no interpreter | |
653 | is specified (i.e., this is no dynamically linked binary. */ | |
654 | if (_dl_loaded->l_ld == NULL) | |
655 | _exit (1); | |
656 | ||
657 | /* We allow here some platform specific code. */ | |
658 | #ifdef DISTINGUISH_LIB_VERSIONS | |
659 | DISTINGUISH_LIB_VERSIONS; | |
660 | #endif | |
661 | _exit (has_interp ? 0 : 2); | |
662 | } | |
663 | ||
664 | if (! rtld_is_main) | |
665 | /* Initialize the data structures for the search paths for shared | |
666 | objects. */ | |
667 | _dl_init_paths (library_path); | |
668 | ||
669 | /* Put the link_map for ourselves on the chain so it can be found by | |
670 | name. Note that at this point the global chain of link maps contains | |
671 | exactly one element, which is pointed to by _dl_loaded. */ | |
672 | if (! _dl_rtld_map.l_name) | |
673 | /* If not invoked directly, the dynamic linker shared object file was | |
674 | found by the PT_INTERP name. */ | |
675 | _dl_rtld_map.l_name = (char *) _dl_rtld_map.l_libname->name; | |
676 | _dl_rtld_map.l_type = lt_library; | |
677 | _dl_loaded->l_next = &_dl_rtld_map; | |
678 | _dl_rtld_map.l_prev = _dl_loaded; | |
679 | ||
680 | /* We have two ways to specify objects to preload: via environment | |
681 | variable and via the file /etc/ld.so.preload. The latter can also | |
682 | be used when security is enabled. */ | |
683 | preloads = NULL; | |
684 | npreloads = 0; | |
685 | ||
686 | if (__builtin_expect (preloadlist != NULL, 0)) | |
687 | { | |
688 | /* The LD_PRELOAD environment variable gives list of libraries | |
689 | separated by white space or colons that are loaded before the | |
690 | executable's dependencies and prepended to the global scope | |
691 | list. If the binary is running setuid all elements | |
692 | containing a '/' are ignored since it is insecure. */ | |
693 | char *list = strdupa (preloadlist); | |
694 | char *p; | |
695 | ||
696 | HP_TIMING_NOW (start); | |
697 | ||
698 | while ((p = strsep (&list, " :")) != NULL) | |
699 | if (p[0] != '\0' | |
700 | && (__builtin_expect (! __libc_enable_secure, 1) | |
701 | || strchr (p, '/') == NULL)) | |
702 | { | |
703 | struct link_map *new_map = _dl_map_object (_dl_loaded, p, 1, | |
704 | lt_library, 0); | |
705 | if (new_map->l_opencount == 1) | |
706 | /* It is no duplicate. */ | |
707 | ++npreloads; | |
708 | } | |
709 | ||
710 | HP_TIMING_NOW (stop); | |
711 | HP_TIMING_DIFF (diff, start, stop); | |
712 | HP_TIMING_ACCUM_NT (load_time, diff); | |
713 | } | |
714 | ||
715 | /* Read the contents of the file. */ | |
716 | file = _dl_sysdep_read_whole_file ("/etc/ld.so.preload", &file_size, | |
717 | PROT_READ | PROT_WRITE); | |
718 | if (__builtin_expect (file != NULL, 0)) | |
719 | { | |
720 | /* Parse the file. It contains names of libraries to be loaded, | |
721 | separated by white spaces or `:'. It may also contain | |
722 | comments introduced by `#'. */ | |
723 | char *problem; | |
724 | char *runp; | |
725 | size_t rest; | |
726 | ||
727 | /* Eliminate comments. */ | |
728 | runp = file; | |
729 | rest = file_size; | |
730 | while (rest > 0) | |
731 | { | |
732 | char *comment = memchr (runp, '#', rest); | |
733 | if (comment == NULL) | |
734 | break; | |
735 | ||
736 | rest -= comment - runp; | |
737 | do | |
738 | *comment = ' '; | |
739 | while (--rest > 0 && *++comment != '\n'); | |
740 | } | |
741 | ||
742 | /* We have one problematic case: if we have a name at the end of | |
743 | the file without a trailing terminating characters, we cannot | |
744 | place the \0. Handle the case separately. */ | |
745 | if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t' | |
746 | && file[file_size - 1] != '\n' && file[file_size - 1] != ':') | |
747 | { | |
748 | problem = &file[file_size]; | |
749 | while (problem > file && problem[-1] != ' ' && problem[-1] != '\t' | |
750 | && problem[-1] != '\n' && problem[-1] != ':') | |
751 | --problem; | |
752 | ||
753 | if (problem > file) | |
754 | problem[-1] = '\0'; | |
755 | } | |
756 | else | |
757 | { | |
758 | problem = NULL; | |
759 | file[file_size - 1] = '\0'; | |
760 | } | |
761 | ||
762 | HP_TIMING_NOW (start); | |
763 | ||
764 | if (file != problem) | |
765 | { | |
766 | char *p; | |
767 | runp = file; | |
768 | while ((p = strsep (&runp, ": \t\n")) != NULL) | |
769 | if (p[0] != '\0') | |
770 | { | |
771 | struct link_map *new_map = _dl_map_object (_dl_loaded, p, 1, | |
772 | lt_library, 0); | |
773 | if (new_map->l_opencount == 1) | |
774 | /* It is no duplicate. */ | |
775 | ++npreloads; | |
776 | } | |
777 | } | |
778 | ||
779 | if (problem != NULL) | |
780 | { | |
781 | char *p = strndupa (problem, file_size - (problem - file)); | |
782 | struct link_map *new_map = _dl_map_object (_dl_loaded, p, 1, | |
783 | lt_library, 0); | |
784 | if (new_map->l_opencount == 1) | |
785 | /* It is no duplicate. */ | |
786 | ++npreloads; | |
787 | } | |
788 | ||
789 | HP_TIMING_NOW (stop); | |
790 | HP_TIMING_DIFF (diff, start, stop); | |
791 | HP_TIMING_ACCUM_NT (load_time, diff); | |
792 | ||
793 | /* We don't need the file anymore. */ | |
794 | __munmap (file, file_size); | |
795 | } | |
796 | ||
797 | if (__builtin_expect (npreloads, 0) != 0) | |
798 | { | |
799 | /* Set up PRELOADS with a vector of the preloaded libraries. */ | |
800 | struct link_map *l; | |
801 | preloads = __alloca (npreloads * sizeof preloads[0]); | |
802 | l = _dl_rtld_map.l_next; /* End of the chain before preloads. */ | |
803 | i = 0; | |
804 | do | |
805 | { | |
806 | preloads[i++] = l; | |
807 | l = l->l_next; | |
808 | } while (l); | |
809 | assert (i == npreloads); | |
810 | } | |
811 | ||
812 | /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD | |
813 | specified some libraries to load, these are inserted before the actual | |
814 | dependencies in the executable's searchlist for symbol resolution. */ | |
815 | HP_TIMING_NOW (start); | |
816 | _dl_map_object_deps (_dl_loaded, preloads, npreloads, mode == trace); | |
817 | HP_TIMING_NOW (stop); | |
818 | HP_TIMING_DIFF (diff, start, stop); | |
819 | HP_TIMING_ACCUM_NT (load_time, diff); | |
820 | ||
821 | /* Mark all objects as being in the global scope. */ | |
822 | for (i = _dl_loaded->l_searchlist.r_nlist; i > 0; ) | |
823 | _dl_loaded->l_searchlist.r_list[--i]->l_global = 1; | |
824 | ||
825 | #ifndef MAP_ANON | |
826 | /* We are done mapping things, so close the zero-fill descriptor. */ | |
827 | __close (_dl_zerofd); | |
828 | _dl_zerofd = -1; | |
829 | #endif | |
830 | ||
831 | /* Remove _dl_rtld_map from the chain. */ | |
832 | _dl_rtld_map.l_prev->l_next = _dl_rtld_map.l_next; | |
833 | if (_dl_rtld_map.l_next) | |
834 | _dl_rtld_map.l_next->l_prev = _dl_rtld_map.l_prev; | |
835 | ||
836 | if (__builtin_expect (_dl_rtld_map.l_opencount, 2) > 1) | |
837 | { | |
838 | /* Some DT_NEEDED entry referred to the interpreter object itself, so | |
839 | put it back in the list of visible objects. We insert it into the | |
840 | chain in symbol search order because gdb uses the chain's order as | |
841 | its symbol search order. */ | |
842 | i = 1; | |
843 | while (_dl_loaded->l_searchlist.r_list[i] != &_dl_rtld_map) | |
844 | ++i; | |
845 | _dl_rtld_map.l_prev = _dl_loaded->l_searchlist.r_list[i - 1]; | |
846 | if (__builtin_expect (mode, normal) == normal) | |
847 | _dl_rtld_map.l_next = (i + 1 < _dl_loaded->l_searchlist.r_nlist | |
848 | ? _dl_loaded->l_searchlist.r_list[i + 1] | |
849 | : NULL); | |
850 | else | |
851 | /* In trace mode there might be an invisible object (which we | |
852 | could not find) after the previous one in the search list. | |
853 | In this case it doesn't matter much where we put the | |
854 | interpreter object, so we just initialize the list pointer so | |
855 | that the assertion below holds. */ | |
856 | _dl_rtld_map.l_next = _dl_rtld_map.l_prev->l_next; | |
857 | ||
858 | assert (_dl_rtld_map.l_prev->l_next == _dl_rtld_map.l_next); | |
859 | _dl_rtld_map.l_prev->l_next = &_dl_rtld_map; | |
860 | if (_dl_rtld_map.l_next) | |
861 | { | |
862 | assert (_dl_rtld_map.l_next->l_prev == _dl_rtld_map.l_prev); | |
863 | _dl_rtld_map.l_next->l_prev = &_dl_rtld_map; | |
864 | } | |
865 | } | |
866 | ||
867 | /* Now let us see whether all libraries are available in the | |
868 | versions we need. */ | |
869 | { | |
870 | struct version_check_args args; | |
871 | args.doexit = mode == normal; | |
872 | args.dotrace = mode == trace; | |
873 | _dl_receive_error (print_missing_version, version_check_doit, &args); | |
874 | } | |
875 | ||
876 | if (__builtin_expect (mode, normal) != normal) | |
877 | { | |
878 | /* We were run just to list the shared libraries. It is | |
879 | important that we do this before real relocation, because the | |
880 | functions we call below for output may no longer work properly | |
881 | after relocation. */ | |
882 | if (! _dl_loaded->l_info[DT_NEEDED]) | |
883 | _dl_sysdep_message ("\t", "statically linked\n", NULL); | |
884 | else | |
885 | { | |
886 | struct link_map *l; | |
887 | ||
888 | for (l = _dl_loaded->l_next; l; l = l->l_next) | |
889 | if (l->l_opencount == 0) | |
890 | /* The library was not found. */ | |
891 | _dl_sysdep_message ("\t", l->l_libname->name, " => not found\n", | |
892 | NULL); | |
893 | else | |
894 | { | |
895 | char buf[20], *bp; | |
896 | buf[sizeof buf - 1] = '\0'; | |
897 | bp = _itoa_word (l->l_addr, &buf[sizeof buf - 1], 16, 0); | |
898 | while ((size_t) (&buf[sizeof buf - 1] - bp) | |
899 | < sizeof l->l_addr * 2) | |
900 | *--bp = '0'; | |
901 | _dl_sysdep_message ("\t", l->l_libname->name, " => ", | |
902 | l->l_name, " (0x", bp, ")\n", NULL); | |
903 | } | |
904 | } | |
905 | ||
906 | if (__builtin_expect (mode, trace) != trace) | |
907 | for (i = 1; i < _dl_argc; ++i) | |
908 | { | |
909 | const ElfW(Sym) *ref = NULL; | |
910 | ElfW(Addr) loadbase; | |
911 | lookup_t result; | |
912 | char buf[20], *bp; | |
913 | ||
914 | result = _dl_lookup_symbol (_dl_argv[i], _dl_loaded, | |
915 | &ref, _dl_loaded->l_scope, | |
916 | ELF_MACHINE_JMP_SLOT); | |
917 | ||
918 | loadbase = LOOKUP_VALUE_ADDRESS (result); | |
919 | ||
920 | buf[sizeof buf - 1] = '\0'; | |
921 | bp = _itoa_word (ref->st_value, &buf[sizeof buf - 1], 16, 0); | |
922 | while ((size_t) (&buf[sizeof buf - 1] - bp) < sizeof loadbase * 2) | |
923 | *--bp = '0'; | |
924 | _dl_sysdep_message (_dl_argv[i], " found at 0x", bp, NULL); | |
925 | buf[sizeof buf - 1] = '\0'; | |
926 | bp = _itoa_word (loadbase, &buf[sizeof buf - 1], 16, 0); | |
927 | while ((size_t) (&buf[sizeof buf - 1] - bp) < sizeof loadbase * 2) | |
928 | *--bp = '0'; | |
929 | _dl_sysdep_message (" in object at 0x", bp, "\n", NULL); | |
930 | } | |
931 | else | |
932 | { | |
933 | if (_dl_lazy >= 0) | |
934 | { | |
935 | /* We have to do symbol dependency testing. */ | |
936 | struct relocate_args args; | |
937 | struct link_map *l; | |
938 | ||
939 | args.lazy = _dl_lazy; | |
940 | ||
941 | l = _dl_loaded; | |
942 | while (l->l_next) | |
943 | l = l->l_next; | |
944 | do | |
945 | { | |
946 | if (l != &_dl_rtld_map && l->l_opencount > 0) | |
947 | { | |
948 | args.l = l; | |
949 | _dl_receive_error (print_unresolved, relocate_doit, | |
950 | &args); | |
951 | } | |
952 | l = l->l_prev; | |
953 | } while (l); | |
954 | } | |
955 | ||
956 | #define VERNEEDTAG (DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGIDX (DT_VERNEED)) | |
957 | if (version_info) | |
958 | { | |
959 | /* Print more information. This means here, print information | |
960 | about the versions needed. */ | |
961 | int first = 1; | |
962 | struct link_map *map = _dl_loaded; | |
963 | ||
964 | for (map = _dl_loaded; map != NULL; map = map->l_next) | |
965 | { | |
966 | const char *strtab; | |
967 | ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG]; | |
968 | ElfW(Verneed) *ent; | |
969 | ||
970 | if (dyn == NULL) | |
971 | continue; | |
972 | ||
973 | strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]); | |
974 | ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr); | |
975 | ||
976 | if (first) | |
977 | { | |
978 | _dl_sysdep_message ("\n\tVersion information:\n", NULL); | |
979 | first = 0; | |
980 | } | |
981 | ||
982 | _dl_sysdep_message ("\t", (map->l_name[0] | |
983 | ? map->l_name : _dl_argv[0]), | |
984 | ":\n", NULL); | |
985 | ||
986 | while (1) | |
987 | { | |
988 | ElfW(Vernaux) *aux; | |
989 | struct link_map *needed; | |
990 | ||
991 | needed = find_needed (strtab + ent->vn_file); | |
992 | aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux); | |
993 | ||
994 | while (1) | |
995 | { | |
996 | const char *fname = NULL; | |
997 | ||
998 | _dl_sysdep_message ("\t\t", | |
999 | strtab + ent->vn_file, | |
1000 | " (", strtab + aux->vna_name, | |
1001 | ") ", | |
1002 | (aux->vna_flags | |
1003 | & VER_FLG_WEAK | |
1004 | ? "[WEAK] " : ""), | |
1005 | "=> ", NULL); | |
1006 | ||
1007 | if (needed != NULL | |
1008 | && match_version (strtab+aux->vna_name, needed)) | |
1009 | fname = needed->l_name; | |
1010 | ||
1011 | _dl_sysdep_message (fname ?: "not found", "\n", | |
1012 | NULL); | |
1013 | ||
1014 | if (aux->vna_next == 0) | |
1015 | /* No more symbols. */ | |
1016 | break; | |
1017 | ||
1018 | /* Next symbol. */ | |
1019 | aux = (ElfW(Vernaux) *) ((char *) aux | |
1020 | + aux->vna_next); | |
1021 | } | |
1022 | ||
1023 | if (ent->vn_next == 0) | |
1024 | /* No more dependencies. */ | |
1025 | break; | |
1026 | ||
1027 | /* Next dependency. */ | |
1028 | ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next); | |
1029 | } | |
1030 | } | |
1031 | } | |
1032 | } | |
1033 | ||
1034 | _exit (0); | |
1035 | } | |
1036 | ||
1037 | { | |
1038 | /* Now we have all the objects loaded. Relocate them all except for | |
1039 | the dynamic linker itself. We do this in reverse order so that copy | |
1040 | relocs of earlier objects overwrite the data written by later | |
1041 | objects. We do not re-relocate the dynamic linker itself in this | |
1042 | loop because that could result in the GOT entries for functions we | |
1043 | call being changed, and that would break us. It is safe to relocate | |
1044 | the dynamic linker out of order because it has no copy relocs (we | |
1045 | know that because it is self-contained). */ | |
1046 | ||
1047 | struct link_map *l; | |
1048 | int consider_profiling = _dl_profile != NULL; | |
1049 | #ifndef HP_TIMING_NONAVAIL | |
1050 | hp_timing_t start; | |
1051 | hp_timing_t stop; | |
1052 | hp_timing_t add; | |
1053 | #endif | |
1054 | ||
1055 | /* If we are profiling we also must do lazy reloaction. */ | |
1056 | _dl_lazy |= consider_profiling; | |
1057 | ||
1058 | l = _dl_loaded; | |
1059 | while (l->l_next) | |
1060 | l = l->l_next; | |
1061 | ||
1062 | HP_TIMING_NOW (start); | |
1063 | do | |
1064 | { | |
1065 | if (l != &_dl_rtld_map) | |
1066 | _dl_relocate_object (l, l->l_scope, _dl_lazy, consider_profiling); | |
1067 | ||
1068 | l = l->l_prev; | |
1069 | } | |
1070 | while (l); | |
1071 | HP_TIMING_NOW (stop); | |
1072 | ||
1073 | HP_TIMING_DIFF (relocate_time, start, stop); | |
1074 | ||
1075 | /* Do any necessary cleanups for the startup OS interface code. | |
1076 | We do these now so that no calls are made after rtld re-relocation | |
1077 | which might be resolved to different functions than we expect. | |
1078 | We cannot do this before relocating the other objects because | |
1079 | _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */ | |
1080 | _dl_sysdep_start_cleanup (); | |
1081 | ||
1082 | /* Now enable profiling if needed. Like the previous call, | |
1083 | this has to go here because the calls it makes should use the | |
1084 | rtld versions of the functions (particularly calloc()), but it | |
1085 | needs to have _dl_profile_map set up by the relocator. */ | |
1086 | if (__builtin_expect (_dl_profile_map != NULL, 0)) | |
1087 | /* We must prepare the profiling. */ | |
1088 | _dl_start_profile (_dl_profile_map, _dl_profile_output); | |
1089 | ||
1090 | if (_dl_rtld_map.l_opencount > 1) | |
1091 | { | |
1092 | /* There was an explicit ref to the dynamic linker as a shared lib. | |
1093 | Re-relocate ourselves with user-controlled symbol definitions. */ | |
1094 | HP_TIMING_NOW (start); | |
1095 | _dl_relocate_object (&_dl_rtld_map, _dl_loaded->l_scope, 0, 0); | |
1096 | HP_TIMING_NOW (stop); | |
1097 | HP_TIMING_DIFF (add, start, stop); | |
1098 | HP_TIMING_ACCUM_NT (relocate_time, add); | |
1099 | } | |
1100 | } | |
1101 | ||
1102 | /* Now set up the variable which helps the assembler startup code. */ | |
1103 | _dl_main_searchlist = &_dl_loaded->l_searchlist; | |
1104 | _dl_global_scope[0] = &_dl_loaded->l_searchlist; | |
1105 | ||
1106 | /* Safe the information about the original global scope list since | |
1107 | we need it in the memory handling later. */ | |
1108 | _dl_initial_searchlist = *_dl_main_searchlist; | |
1109 | ||
1110 | { | |
1111 | /* Initialize _r_debug. */ | |
1112 | struct r_debug *r = _dl_debug_initialize (_dl_rtld_map.l_addr); | |
1113 | struct link_map *l; | |
1114 | ||
1115 | l = _dl_loaded; | |
1116 | ||
1117 | #ifdef ELF_MACHINE_DEBUG_SETUP | |
1118 | ||
1119 | /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */ | |
1120 | ||
1121 | ELF_MACHINE_DEBUG_SETUP (l, r); | |
1122 | ELF_MACHINE_DEBUG_SETUP (&_dl_rtld_map, r); | |
1123 | ||
1124 | #else | |
1125 | ||
1126 | if (l->l_info[DT_DEBUG]) | |
1127 | /* There is a DT_DEBUG entry in the dynamic section. Fill it in | |
1128 | with the run-time address of the r_debug structure */ | |
1129 | l->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r; | |
1130 | ||
1131 | /* Fill in the pointer in the dynamic linker's own dynamic section, in | |
1132 | case you run gdb on the dynamic linker directly. */ | |
1133 | if (_dl_rtld_map.l_info[DT_DEBUG]) | |
1134 | _dl_rtld_map.l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r; | |
1135 | ||
1136 | #endif | |
1137 | ||
1138 | /* Notify the debugger that all objects are now mapped in. */ | |
1139 | r->r_state = RT_ADD; | |
1140 | _dl_debug_state (); | |
1141 | } | |
1142 | ||
1143 | #ifndef MAP_COPY | |
1144 | /* We must munmap() the cache file. */ | |
1145 | _dl_unload_cache (); | |
1146 | #endif | |
1147 | ||
1148 | /* Once we return, _dl_sysdep_start will invoke | |
1149 | the DT_INIT functions and then *USER_ENTRY. */ | |
1150 | } | |
1151 | \f | |
1152 | /* This is a little helper function for resolving symbols while | |
1153 | tracing the binary. */ | |
1154 | static void | |
1155 | print_unresolved (int errcode __attribute__ ((unused)), const char *objname, | |
1156 | const char *errstring) | |
1157 | { | |
1158 | if (objname[0] == '\0') | |
1159 | objname = _dl_argv[0] ?: "<main program>"; | |
1160 | _dl_sysdep_error (errstring, " (", objname, ")\n", NULL); | |
1161 | } | |
1162 | \f | |
1163 | /* This is a little helper function for resolving symbols while | |
1164 | tracing the binary. */ | |
1165 | static void | |
1166 | print_missing_version (int errcode __attribute__ ((unused)), | |
1167 | const char *objname, const char *errstring) | |
1168 | { | |
1169 | _dl_sysdep_error (_dl_argv[0] ?: "<program name unknown>", ": ", | |
1170 | objname, ": ", errstring, "\n", NULL); | |
1171 | } | |
1172 | \f | |
1173 | /* Nonzero if any of the debugging options is enabled. */ | |
1174 | static int any_debug; | |
1175 | ||
1176 | /* Process the string given as the parameter which explains which debugging | |
1177 | options are enabled. */ | |
1178 | static void | |
1179 | process_dl_debug (const char *dl_debug) | |
1180 | { | |
1181 | size_t len; | |
1182 | #define separators " ,:" | |
1183 | do | |
1184 | { | |
1185 | len = 0; | |
1186 | /* Skip separating white spaces and commas. */ | |
1187 | dl_debug += strspn (dl_debug, separators); | |
1188 | if (*dl_debug != '\0') | |
1189 | { | |
1190 | len = strcspn (dl_debug, separators); | |
1191 | ||
1192 | switch (len) | |
1193 | { | |
1194 | case 3: | |
1195 | /* This option is not documented since it is not generally | |
1196 | useful. */ | |
1197 | if (memcmp (dl_debug, "all", 3) == 0) | |
1198 | { | |
1199 | _dl_debug_libs = 1; | |
1200 | _dl_debug_impcalls = 1; | |
1201 | _dl_debug_reloc = 1; | |
1202 | _dl_debug_files = 1; | |
1203 | _dl_debug_symbols = 1; | |
1204 | _dl_debug_bindings = 1; | |
1205 | _dl_debug_versions = 1; | |
1206 | any_debug = 1; | |
1207 | continue; | |
1208 | } | |
1209 | break; | |
1210 | ||
1211 | case 4: | |
1212 | if (memcmp (dl_debug, "help", 4) == 0) | |
1213 | { | |
1214 | _dl_sysdep_message ("\ | |
1215 | Valid options for the LD_DEBUG environment variable are:\n\ | |
1216 | \n\ | |
1217 | bindings display information about symbol binding\n\ | |
1218 | files display processing of files and libraries\n\ | |
1219 | help display this help message and exit\n\ | |
1220 | libs display library search paths\n\ | |
1221 | reloc display relocation processing\n\ | |
1222 | statistics display relocation statistics\n\ | |
1223 | symbols display symbol table processing\n\ | |
1224 | versions display version dependencies\n\ | |
1225 | \n\ | |
1226 | To direct the debugging output into a file instead of standard output\n\ | |
1227 | a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n", | |
1228 | NULL); | |
1229 | _exit (0); | |
1230 | } | |
1231 | ||
1232 | if (memcmp (dl_debug, "libs", 4) == 0) | |
1233 | { | |
1234 | _dl_debug_libs = 1; | |
1235 | _dl_debug_impcalls = 1; | |
1236 | any_debug = 1; | |
1237 | continue; | |
1238 | } | |
1239 | break; | |
1240 | ||
1241 | case 5: | |
1242 | if (memcmp (dl_debug, "reloc", 5) == 0) | |
1243 | { | |
1244 | _dl_debug_reloc = 1; | |
1245 | _dl_debug_impcalls = 1; | |
1246 | any_debug = 1; | |
1247 | continue; | |
1248 | } | |
1249 | ||
1250 | if (memcmp (dl_debug, "files", 5) == 0) | |
1251 | { | |
1252 | _dl_debug_files = 1; | |
1253 | _dl_debug_impcalls = 1; | |
1254 | any_debug = 1; | |
1255 | continue; | |
1256 | } | |
1257 | break; | |
1258 | ||
1259 | case 7: | |
1260 | if (memcmp (dl_debug, "symbols", 7) == 0) | |
1261 | { | |
1262 | _dl_debug_symbols = 1; | |
1263 | _dl_debug_impcalls = 1; | |
1264 | any_debug = 1; | |
1265 | continue; | |
1266 | } | |
1267 | break; | |
1268 | ||
1269 | case 8: | |
1270 | if (memcmp (dl_debug, "bindings", 8) == 0) | |
1271 | { | |
1272 | _dl_debug_bindings = 1; | |
1273 | _dl_debug_impcalls = 1; | |
1274 | any_debug = 1; | |
1275 | continue; | |
1276 | } | |
1277 | ||
1278 | if (memcmp (dl_debug, "versions", 8) == 0) | |
1279 | { | |
1280 | _dl_debug_versions = 1; | |
1281 | _dl_debug_impcalls = 1; | |
1282 | any_debug = 1; | |
1283 | continue; | |
1284 | } | |
1285 | break; | |
1286 | ||
1287 | case 10: | |
1288 | if (memcmp (dl_debug, "statistics", 10) == 0) | |
1289 | { | |
1290 | _dl_debug_statistics = 1; | |
1291 | continue; | |
1292 | } | |
1293 | break; | |
1294 | ||
1295 | default: | |
1296 | break; | |
1297 | } | |
1298 | ||
1299 | { | |
1300 | /* Display a warning and skip everything until next separator. */ | |
1301 | char *startp = strndupa (dl_debug, len); | |
1302 | _dl_sysdep_error ("warning: debug option `", startp, | |
1303 | "' unknown; try LD_DEBUG=help\n", NULL); | |
1304 | break; | |
1305 | } | |
1306 | } | |
1307 | } | |
1308 | while (*(dl_debug += len) != '\0'); | |
1309 | } | |
1310 | \f | |
1311 | /* Process all environments variables the dynamic linker must recognize. | |
1312 | Since all of them start with `LD_' we are a bit smarter while finding | |
1313 | all the entries. */ | |
1314 | static void | |
1315 | process_envvars (enum mode *modep, int *lazyp) | |
1316 | { | |
1317 | char **runp = NULL; | |
1318 | char *envline; | |
1319 | enum mode mode = normal; | |
1320 | int bind_now = 0; | |
1321 | char *debug_output = NULL; | |
1322 | ||
1323 | /* This is the default place for profiling data file. */ | |
1324 | _dl_profile_output = "/var/tmp"; | |
1325 | ||
1326 | while ((envline = _dl_next_ld_env_entry (&runp)) != NULL) | |
1327 | { | |
1328 | size_t len = strcspn (envline, "="); | |
1329 | ||
1330 | if (envline[len] != '=') | |
1331 | /* This is a "LD_" variable at the end of the string without | |
1332 | a '=' character. Ignore it since otherwise we will access | |
1333 | invalid memory below. */ | |
1334 | break; | |
1335 | ||
1336 | switch (len - 3) | |
1337 | { | |
1338 | case 4: | |
1339 | /* Warning level, verbose or not. */ | |
1340 | if (memcmp (&envline[3], "WARN", 4) == 0) | |
1341 | _dl_verbose = envline[8] != '\0'; | |
1342 | break; | |
1343 | ||
1344 | case 5: | |
1345 | /* Debugging of the dynamic linker? */ | |
1346 | if (memcmp (&envline[3], "DEBUG", 5) == 0) | |
1347 | process_dl_debug (&envline[9]); | |
1348 | break; | |
1349 | ||
1350 | case 7: | |
1351 | /* Print information about versions. */ | |
1352 | if (memcmp (&envline[3], "VERBOSE", 7) == 0) | |
1353 | { | |
1354 | version_info = envline[11] != '\0'; | |
1355 | break; | |
1356 | } | |
1357 | ||
1358 | /* List of objects to be preloaded. */ | |
1359 | if (memcmp (&envline[3], "PRELOAD", 7) == 0) | |
1360 | { | |
1361 | preloadlist = &envline[11]; | |
1362 | break; | |
1363 | } | |
1364 | ||
1365 | /* Which shared object shall be profiled. */ | |
1366 | if (memcmp (&envline[3], "PROFILE", 7) == 0) | |
1367 | _dl_profile = &envline[11]; | |
1368 | break; | |
1369 | ||
1370 | case 8: | |
1371 | /* Do we bind early? */ | |
1372 | if (memcmp (&envline[3], "BIND_NOW", 8) == 0) | |
1373 | bind_now = envline[12] != '\0'; | |
1374 | break; | |
1375 | ||
1376 | case 9: | |
1377 | /* Test whether we want to see the content of the auxiliary | |
1378 | array passed up from the kernel. */ | |
1379 | if (memcmp (&envline[3], "SHOW_AUXV", 9) == 0) | |
1380 | _dl_show_auxv (); | |
1381 | break; | |
1382 | ||
1383 | case 10: | |
1384 | /* Mask for the important hardware capabilities. */ | |
1385 | if (memcmp (&envline[3], "HWCAP_MASK", 10) == 0) | |
1386 | _dl_hwcap_mask = strtoul (&envline[14], NULL, 0); | |
1387 | break; | |
1388 | ||
1389 | case 11: | |
1390 | /* Path where the binary is found. */ | |
1391 | if (!__libc_enable_secure | |
1392 | && memcmp (&envline[3], "ORIGIN_PATH", 11) == 0) | |
1393 | _dl_origin_path = &envline[15]; | |
1394 | break; | |
1395 | ||
1396 | case 12: | |
1397 | /* The library search path. */ | |
1398 | if (memcmp (&envline[3], "LIBRARY_PATH", 12) == 0) | |
1399 | { | |
1400 | library_path = &envline[16]; | |
1401 | break; | |
1402 | } | |
1403 | ||
1404 | /* Where to place the profiling data file. */ | |
1405 | if (memcmp (&envline[3], "DEBUG_OUTPUT", 12) == 0) | |
1406 | { | |
1407 | debug_output = &envline[16]; | |
1408 | break; | |
1409 | } | |
1410 | ||
1411 | if (memcmp (&envline[3], "DYNAMIC_WEAK", 12) == 0) | |
1412 | _dl_dynamic_weak = 1; | |
1413 | break; | |
1414 | ||
1415 | case 14: | |
1416 | /* Where to place the profiling data file. */ | |
1417 | if (!__libc_enable_secure | |
1418 | && memcmp (&envline[3], "PROFILE_OUTPUT", 14) == 0) | |
1419 | { | |
1420 | _dl_profile_output = &envline[18]; | |
1421 | if (*_dl_profile_output == '\0') | |
1422 | _dl_profile_output = "/var/tmp"; | |
1423 | } | |
1424 | break; | |
1425 | ||
1426 | case 20: | |
1427 | /* The mode of the dynamic linker can be set. */ | |
1428 | if (memcmp (&envline[3], "TRACE_LOADED_OBJECTS", 20) == 0) | |
1429 | mode = trace; | |
1430 | break; | |
1431 | ||
1432 | /* We might have some extra environment variable to handle. This | |
1433 | is tricky due to the pre-processing of the length of the name | |
1434 | in the switch statement here. The code here assumes that added | |
1435 | environment variables have a different length. */ | |
1436 | #ifdef EXTRA_LD_ENVVARS | |
1437 | EXTRA_LD_ENVVARS | |
1438 | #endif | |
1439 | } | |
1440 | } | |
1441 | ||
1442 | /* Extra security for SUID binaries. Remove all dangerous environment | |
1443 | variables. */ | |
1444 | if (__libc_enable_secure) | |
1445 | { | |
1446 | static const char *unsecure_envvars[] = | |
1447 | { | |
1448 | #ifdef EXTRA_UNSECURE_ENVVARS | |
1449 | EXTRA_UNSECURE_ENVVARS | |
1450 | #endif | |
1451 | }; | |
1452 | size_t cnt; | |
1453 | ||
1454 | if (preloadlist != NULL) | |
1455 | unsetenv ("LD_PRELOAD"); | |
1456 | if (library_path != NULL) | |
1457 | unsetenv ("LD_LIBRARY_PATH"); | |
1458 | if (_dl_origin_path != NULL) | |
1459 | unsetenv ("LD_ORIGIN_PATH"); | |
1460 | if (debug_output != NULL) | |
1461 | unsetenv ("LD_DEBUG_OUTPUT"); | |
1462 | if (_dl_profile != NULL) | |
1463 | unsetenv ("LD_PROFILE"); | |
1464 | ||
1465 | for (cnt = 0; | |
1466 | cnt < sizeof (unsecure_envvars) / sizeof (unsecure_envvars[0]); | |
1467 | ++cnt) | |
1468 | unsetenv (unsecure_envvars[cnt]); | |
1469 | } | |
1470 | ||
1471 | /* The name of the object to profile cannot be empty. */ | |
1472 | if (_dl_profile != NULL && *_dl_profile == '\0') | |
1473 | _dl_profile = NULL; | |
1474 | ||
1475 | /* If we have to run the dynamic linker in debugging mode and the | |
1476 | LD_DEBUG_OUTPUT environment variable is given, we write the debug | |
1477 | messages to this file. */ | |
1478 | if (any_debug && debug_output != NULL && !__libc_enable_secure) | |
1479 | { | |
1480 | size_t name_len = strlen (debug_output); | |
1481 | char buf[name_len + 12]; | |
1482 | char *startp; | |
1483 | ||
1484 | buf[name_len + 11] = '\0'; | |
1485 | startp = _itoa_word (__getpid (), &buf[name_len + 11], 10, 0); | |
1486 | *--startp = '.'; | |
1487 | startp = memcpy (startp - name_len, debug_output, name_len); | |
1488 | ||
1489 | _dl_debug_fd = __open (startp, O_WRONLY | O_APPEND | O_CREAT, 0666); | |
1490 | if (_dl_debug_fd == -1) | |
1491 | /* We use standard output if opening the file failed. */ | |
1492 | _dl_debug_fd = STDOUT_FILENO; | |
1493 | } | |
1494 | ||
1495 | /* LAZY is determined by the environment variable LD_WARN and | |
1496 | LD_BIND_NOW if we trace the binary. */ | |
1497 | if (__builtin_expect (mode, normal) == trace) | |
1498 | *lazyp = _dl_verbose ? !bind_now : -1; | |
1499 | else | |
1500 | *lazyp = !bind_now; | |
1501 | ||
1502 | *modep = mode; | |
1503 | } | |
1504 | ||
1505 | ||
1506 | /* Print the various times we collected. */ | |
1507 | static void | |
1508 | print_statistics (void) | |
1509 | { | |
1510 | char buf[200]; | |
1511 | #ifndef HP_TIMING_NONAVAIL | |
1512 | char *cp; | |
1513 | char *wp; | |
1514 | ||
1515 | /* Total time rtld used. */ | |
1516 | if (HP_TIMING_AVAIL) | |
1517 | { | |
1518 | HP_TIMING_PRINT (buf, sizeof (buf), rtld_total_time); | |
1519 | _dl_debug_message (1, "\nruntime linker statistics:\n" | |
1520 | " total startup time in dynamic loader: ", | |
1521 | buf, "\n", NULL); | |
1522 | } | |
1523 | ||
1524 | /* Print relocation statistics. */ | |
1525 | if (HP_TIMING_AVAIL) | |
1526 | { | |
1527 | HP_TIMING_PRINT (buf, sizeof (buf), relocate_time); | |
1528 | _dl_debug_message (1, " time needed for relocation: ", buf, | |
1529 | NULL); | |
1530 | cp = _itoa_word ((1000 * relocate_time) / rtld_total_time, | |
1531 | buf + sizeof (buf), 10, 0); | |
1532 | wp = buf; | |
1533 | switch (buf + sizeof (buf) - cp) | |
1534 | { | |
1535 | case 3: | |
1536 | *wp++ = *cp++; | |
1537 | case 2: | |
1538 | *wp++ = *cp++; | |
1539 | case 1: | |
1540 | *wp++ = '.'; | |
1541 | *wp++ = *cp++; | |
1542 | } | |
1543 | *wp = '\0'; | |
1544 | _dl_debug_message (0, " (", buf, "%)\n", NULL); | |
1545 | } | |
1546 | #endif | |
1547 | buf[sizeof (buf) - 1] = '\0'; | |
1548 | _dl_debug_message (1, " number of relocations: ", | |
1549 | _itoa_word (_dl_num_relocations, | |
1550 | buf + sizeof (buf) - 1, 10, 0), | |
1551 | "\n", NULL); | |
1552 | ||
1553 | #ifndef HP_TIMING_NONAVAIL | |
1554 | /* Time spend while loading the object and the dependencies. */ | |
1555 | if (HP_TIMING_AVAIL) | |
1556 | { | |
1557 | HP_TIMING_PRINT (buf, sizeof (buf), load_time); | |
1558 | _dl_debug_message (1, " time needed to load objects: ", buf, | |
1559 | NULL); | |
1560 | cp = _itoa_word ((1000 * load_time) / rtld_total_time, | |
1561 | buf + sizeof (buf), 10, 0); | |
1562 | wp = buf; | |
1563 | switch (buf + sizeof (buf) - cp) | |
1564 | { | |
1565 | case 3: | |
1566 | *wp++ = *cp++; | |
1567 | case 2: | |
1568 | *wp++ = *cp++; | |
1569 | case 1: | |
1570 | *wp++ = '.'; | |
1571 | *wp++ = *cp++; | |
1572 | } | |
1573 | *wp = '\0'; | |
1574 | _dl_debug_message (0, " (", buf, "%)\n", NULL); | |
1575 | } | |
1576 | #endif | |
1577 | } |