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Commit | Line | Data |
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d66e34cd | 1 | /* Run time dynamic linker. |
49891c10 | 2 | Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc. |
afd4eb37 | 3 | This file is part of the GNU C Library. |
d66e34cd | 4 | |
afd4eb37 UD |
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. | |
d66e34cd | 9 | |
afd4eb37 UD |
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. | |
d66e34cd | 14 | |
afd4eb37 UD |
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. */ | |
d66e34cd | 19 | |
7dea968e | 20 | #include <fcntl.h> |
d66e34cd | 21 | #include <stdlib.h> |
f51d1dfd | 22 | #include <string.h> |
d66e34cd | 23 | #include <unistd.h> |
2064087b | 24 | #include <sys/mman.h> /* Check if MAP_ANON is defined. */ |
a853022c | 25 | #include <elf/ldsodefs.h> |
ce37fa88 | 26 | #include <stdio-common/_itoa.h> |
f21acc89 | 27 | #include <entry.h> |
c94a8080 | 28 | #include <fpu_control.h> |
f5348425 | 29 | #include "dynamic-link.h" |
e2102c14 | 30 | #include "dl-librecon.h" |
f5348425 | 31 | |
a853022c | 32 | #include <assert.h> |
f5348425 | 33 | |
d66e34cd RM |
34 | /* System-specific function to do initial startup for the dynamic linker. |
35 | After this, file access calls and getenv must work. This is responsible | |
cddcfecf | 36 | for setting __libc_enable_secure if we need to be secure (e.g. setuid), |
d66e34cd | 37 | and for setting _dl_argc and _dl_argv, and then calling _dl_main. */ |
266180eb RM |
38 | extern ElfW(Addr) _dl_sysdep_start (void **start_argptr, |
39 | void (*dl_main) (const ElfW(Phdr) *phdr, | |
40 | ElfW(Half) phent, | |
41 | ElfW(Addr) *user_entry)); | |
4cb20290 | 42 | extern void _dl_sysdep_start_cleanup (void); |
d66e34cd | 43 | |
08cac4ac UD |
44 | /* This function is used to unload the cache file if necessary. */ |
45 | extern void _dl_unload_cache (void); | |
46 | ||
14bab8de UD |
47 | /* System-dependent function to read a file's whole contents |
48 | in the most convenient manner available. */ | |
49 | extern void *_dl_sysdep_read_whole_file (const char *filename, | |
50 | size_t *filesize_ptr, | |
51 | int mmap_prot); | |
52 | ||
fd26970f | 53 | /* Helper function to handle errors while resolving symbols. */ |
c84142e8 UD |
54 | static void print_unresolved (int errcode, const char *objname, |
55 | const char *errsting); | |
56 | ||
57 | /* Helper function to handle errors when a version is missing. */ | |
58 | static void print_missing_version (int errcode, const char *objname, | |
59 | const char *errsting); | |
fd26970f | 60 | |
ea278354 UD |
61 | |
62 | /* This is a list of all the modes the dynamic loader can be in. */ | |
63 | enum mode { normal, list, verify, trace }; | |
64 | ||
65 | /* Process all environments variables the dynamic linker must recognize. | |
66 | Since all of them start with `LD_' we are a bit smarter while finding | |
67 | all the entries. */ | |
68 | static void process_envvars (enum mode *modep, int *lazyp); | |
69 | ||
d66e34cd RM |
70 | int _dl_argc; |
71 | char **_dl_argv; | |
ceb27555 | 72 | unsigned int _dl_skip_args; /* Nonzero if we were run directly. */ |
cf29ffbe | 73 | int _dl_verbose; |
0a54e401 UD |
74 | const char *_dl_platform; |
75 | size_t _dl_platformlen; | |
f41c8091 | 76 | unsigned long _dl_hwcap; |
c94a8080 | 77 | fpu_control_t _dl_fpu_control = _FPU_DEFAULT; |
0a54e401 | 78 | struct r_search_path *_dl_search_paths; |
3996f34b UD |
79 | const char *_dl_profile; |
80 | const char *_dl_profile_output; | |
a3d6fb9b | 81 | struct link_map *_dl_profile_map; |
b5efde2f | 82 | int _dl_debug_libs; |
7dea968e | 83 | int _dl_debug_impcalls; |
0c367d92 | 84 | int _dl_debug_bindings; |
de100ca7 | 85 | int _dl_debug_symbols; |
8193034b UD |
86 | int _dl_debug_versions; |
87 | int _dl_debug_reloc; | |
88 | int _dl_debug_files; | |
b0a01055 | 89 | const char *_dl_inhibit_rpath; /* RPATH values which should be |
310930c1 | 90 | ignored. */ |
f787edde | 91 | const char *_dl_origin_path; |
d66e34cd | 92 | |
be935610 UD |
93 | /* This is a pointer to the map for the main object and through it to |
94 | all loaded objects. */ | |
95 | struct link_map *_dl_loaded; | |
96 | /* Pointer to the l_searchlist element of the link map of the main object. */ | |
97 | struct r_scope_elem *_dl_main_searchlist; | |
604510f7 UD |
98 | /* Copy of the content of `_dl_main_searchlist'. */ |
99 | struct r_scope_elem _dl_initial_searchlist; | |
be935610 UD |
100 | /* Array which is used when looking up in the global scope. */ |
101 | struct r_scope_elem *_dl_global_scope[2]; | |
102 | ||
39778c6c UD |
103 | /* Set nonzero during loading and initialization of executable and |
104 | libraries, cleared before the executable's entry point runs. This | |
105 | must not be initialized to nonzero, because the unused dynamic | |
106 | linker loaded in for libc.so's "ld.so.1" dep will provide the | |
107 | definition seen by libc.so's initializer; that value must be zero, | |
108 | and will be since that dynamic linker's _dl_start and dl_main will | |
109 | never be called. */ | |
110 | int _dl_starting_up; | |
111 | ||
c0fb8a56 | 112 | |
266180eb RM |
113 | static void dl_main (const ElfW(Phdr) *phdr, |
114 | ElfW(Half) phent, | |
115 | ElfW(Addr) *user_entry); | |
d66e34cd | 116 | |
ee188d55 | 117 | struct link_map _dl_rtld_map; |
c84142e8 | 118 | struct libname_list _dl_rtld_libname; |
f41c8091 | 119 | struct libname_list _dl_rtld_libname2; |
86d2c878 | 120 | |
b1dbbaa4 RM |
121 | #ifdef RTLD_START |
122 | RTLD_START | |
123 | #else | |
124 | #error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START" | |
125 | #endif | |
126 | ||
ceb2d9aa | 127 | static ElfW(Addr) |
d66e34cd RM |
128 | _dl_start (void *arg) |
129 | { | |
86d2c878 | 130 | struct link_map bootstrap_map; |
d66e34cd | 131 | |
b1dbbaa4 RM |
132 | /* This #define produces dynamic linking inline functions for |
133 | bootstrap relocation instead of general-purpose relocation. */ | |
134 | #define RTLD_BOOTSTRAP | |
c84142e8 | 135 | #define RESOLVE(sym, version, flags) bootstrap_map.l_addr |
b1dbbaa4 RM |
136 | #include "dynamic-link.h" |
137 | ||
d66e34cd | 138 | /* Figure out the run-time load address of the dynamic linker itself. */ |
86d2c878 | 139 | bootstrap_map.l_addr = elf_machine_load_address (); |
d66e34cd | 140 | |
47707456 UD |
141 | /* Read our own dynamic section and fill in the info array. */ |
142 | bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic (); | |
86d2c878 | 143 | elf_get_dynamic_info (bootstrap_map.l_ld, bootstrap_map.l_info); |
d66e34cd RM |
144 | |
145 | #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC | |
86d2c878 | 146 | ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info); |
d66e34cd RM |
147 | #endif |
148 | ||
149 | /* Relocate ourselves so we can do normal function calls and | |
150 | data access using the global offset table. */ | |
421f82e5 | 151 | |
3996f34b | 152 | ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0); |
ea7eb7e3 UD |
153 | /* Please note that we don't allow profiling of this object and |
154 | therefore need not test whether we have to allocate the array | |
155 | for the relocation results (as done in dl-reloc.c). */ | |
421f82e5 | 156 | |
d66e34cd RM |
157 | /* Now life is sane; we can call functions and access global data. |
158 | Set up to use the operating system facilities, and find out from | |
159 | the operating system's program loader where to find the program | |
160 | header table in core. */ | |
161 | ||
86d2c878 | 162 | /* Transfer data about ourselves to the permanent link_map structure. */ |
ee188d55 RM |
163 | _dl_rtld_map.l_addr = bootstrap_map.l_addr; |
164 | _dl_rtld_map.l_ld = bootstrap_map.l_ld; | |
f41c8091 | 165 | _dl_rtld_map.l_opencount = 1; |
ee188d55 RM |
166 | memcpy (_dl_rtld_map.l_info, bootstrap_map.l_info, |
167 | sizeof _dl_rtld_map.l_info); | |
168 | _dl_setup_hash (&_dl_rtld_map); | |
86d2c878 | 169 | |
052b6a6c UD |
170 | /* Don't bother trying to work out how ld.so is mapped in memory. */ |
171 | _dl_rtld_map.l_map_start = ~0; | |
172 | _dl_rtld_map.l_map_end = ~0; | |
173 | ||
d66e34cd RM |
174 | /* Call the OS-dependent function to set up life so we can do things like |
175 | file access. It will call `dl_main' (below) to do all the real work | |
176 | of the dynamic linker, and then unwind our frame and run the user | |
177 | entry point on the same stack we entered on. */ | |
8d6468d0 | 178 | return _dl_sysdep_start (arg, &dl_main); |
d66e34cd RM |
179 | } |
180 | ||
d66e34cd RM |
181 | /* Now life is peachy; we can do all normal operations. |
182 | On to the real work. */ | |
183 | ||
f21acc89 | 184 | void ENTRY_POINT (void); |
d66e34cd | 185 | |
993b3242 UD |
186 | /* Some helper functions. */ |
187 | ||
188 | /* Arguments to relocate_doit. */ | |
189 | struct relocate_args | |
190 | { | |
191 | struct link_map *l; | |
192 | int lazy; | |
193 | }; | |
194 | ||
195 | struct map_args | |
196 | { | |
197 | /* Argument to map_doit. */ | |
198 | char *str; | |
199 | /* Return value of map_doit. */ | |
200 | struct link_map *main_map; | |
201 | }; | |
202 | ||
203 | /* Arguments to version_check_doit. */ | |
204 | struct version_check_args | |
205 | { | |
993b3242 UD |
206 | int doexit; |
207 | }; | |
208 | ||
209 | static void | |
210 | relocate_doit (void *a) | |
211 | { | |
212 | struct relocate_args *args = (struct relocate_args *) a; | |
213 | ||
be935610 | 214 | _dl_relocate_object (args->l, args->l->l_scope, |
c0fb8a56 | 215 | args->lazy, 0); |
993b3242 UD |
216 | } |
217 | ||
218 | static void | |
219 | map_doit (void *a) | |
220 | { | |
be935610 | 221 | struct map_args *args = (struct map_args *) a; |
c6222ab9 | 222 | args->main_map = _dl_map_object (NULL, args->str, 0, lt_library, 0); |
993b3242 UD |
223 | } |
224 | ||
225 | static void | |
226 | version_check_doit (void *a) | |
227 | { | |
be935610 UD |
228 | struct version_check_args *args = (struct version_check_args *) a; |
229 | if (_dl_check_all_versions (_dl_loaded, 1) && args->doexit) | |
993b3242 UD |
230 | /* We cannot start the application. Abort now. */ |
231 | _exit (1); | |
232 | } | |
233 | ||
ce37fa88 UD |
234 | |
235 | static inline struct link_map * | |
236 | find_needed (const char *name) | |
237 | { | |
be935610 | 238 | unsigned int n = _dl_loaded->l_searchlist.r_nlist; |
ce37fa88 | 239 | |
be935610 UD |
240 | while (n-- > 0) |
241 | if (_dl_name_match_p (name, _dl_loaded->l_searchlist.r_list[n])) | |
242 | return _dl_loaded->l_searchlist.r_list[n]; | |
ce37fa88 UD |
243 | |
244 | /* Should never happen. */ | |
245 | return NULL; | |
246 | } | |
247 | ||
248 | static int | |
249 | match_version (const char *string, struct link_map *map) | |
250 | { | |
251 | const char *strtab = (const char *) (map->l_addr | |
252 | + map->l_info[DT_STRTAB]->d_un.d_ptr); | |
253 | ElfW(Verdef) *def; | |
254 | ||
255 | #define VERDEFTAG (DT_NUM + DT_PROCNUM + DT_VERSIONTAGIDX (DT_VERDEF)) | |
256 | if (map->l_info[VERDEFTAG] == NULL) | |
257 | /* The file has no symbol versioning. */ | |
258 | return 0; | |
259 | ||
260 | def = (ElfW(Verdef) *) ((char *) map->l_addr | |
261 | + map->l_info[VERDEFTAG]->d_un.d_ptr); | |
262 | while (1) | |
263 | { | |
264 | ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux); | |
265 | ||
266 | /* Compare the version strings. */ | |
267 | if (strcmp (string, strtab + aux->vda_name) == 0) | |
268 | /* Bingo! */ | |
269 | return 1; | |
270 | ||
271 | /* If no more definitions we failed to find what we want. */ | |
272 | if (def->vd_next == 0) | |
273 | break; | |
274 | ||
275 | /* Next definition. */ | |
276 | def = (ElfW(Verdef) *) ((char *) def + def->vd_next); | |
277 | } | |
278 | ||
279 | return 0; | |
280 | } | |
281 | ||
120b4c49 UD |
282 | static const char *library_path; /* The library search path. */ |
283 | static const char *preloadlist; /* The list preloaded objects. */ | |
284 | static int version_info; /* Nonzero if information about | |
285 | versions has to be printed. */ | |
a1a9d215 | 286 | |
d66e34cd | 287 | static void |
266180eb RM |
288 | dl_main (const ElfW(Phdr) *phdr, |
289 | ElfW(Half) phent, | |
290 | ElfW(Addr) *user_entry) | |
d66e34cd | 291 | { |
266180eb | 292 | const ElfW(Phdr) *ph; |
0200214b | 293 | int lazy; |
ea278354 | 294 | enum mode mode; |
2064087b RM |
295 | struct link_map **preloads; |
296 | unsigned int npreloads; | |
14bab8de UD |
297 | size_t file_size; |
298 | char *file; | |
2f6d1f1b | 299 | int has_interp = 0; |
77aba05b | 300 | unsigned int i; |
5aa8ff62 | 301 | int paths_initialized = 0; |
d66e34cd | 302 | |
ea278354 UD |
303 | /* Process the environment variable which control the behaviour. */ |
304 | process_envvars (&mode, &lazy); | |
3996f34b | 305 | |
46ec036d UD |
306 | /* Set up a flag which tells we are just starting. */ |
307 | _dl_starting_up = 1; | |
308 | ||
f21acc89 | 309 | if (*user_entry == (ElfW(Addr)) &ENTRY_POINT) |
0200214b RM |
310 | { |
311 | /* Ho ho. We are not the program interpreter! We are the program | |
312 | itself! This means someone ran ld.so as a command. Well, that | |
313 | might be convenient to do sometimes. We support it by | |
314 | interpreting the args like this: | |
315 | ||
316 | ld.so PROGRAM ARGS... | |
317 | ||
318 | The first argument is the name of a file containing an ELF | |
319 | executable we will load and run with the following arguments. | |
320 | To simplify life here, PROGRAM is searched for using the | |
321 | normal rules for shared objects, rather than $PATH or anything | |
322 | like that. We just load it and use its entry point; we don't | |
323 | pay attention to its PT_INTERP command (we are the interpreter | |
324 | ourselves). This is an easy way to test a new ld.so before | |
325 | installing it. */ | |
421f82e5 | 326 | |
ffee1316 RM |
327 | /* Note the place where the dynamic linker actually came from. */ |
328 | _dl_rtld_map.l_name = _dl_argv[0]; | |
6a76c115 | 329 | |
fd26970f UD |
330 | while (_dl_argc > 1) |
331 | if (! strcmp (_dl_argv[1], "--list")) | |
332 | { | |
333 | mode = list; | |
334 | lazy = -1; /* This means do no dependency analysis. */ | |
61965e9b | 335 | |
fd26970f UD |
336 | ++_dl_skip_args; |
337 | --_dl_argc; | |
338 | ++_dl_argv; | |
339 | } | |
340 | else if (! strcmp (_dl_argv[1], "--verify")) | |
341 | { | |
342 | mode = verify; | |
6a76c115 | 343 | |
fd26970f UD |
344 | ++_dl_skip_args; |
345 | --_dl_argc; | |
346 | ++_dl_argv; | |
347 | } | |
310930c1 | 348 | else if (! strcmp (_dl_argv[1], "--library-path") && _dl_argc > 2) |
880f421f UD |
349 | { |
350 | library_path = _dl_argv[2]; | |
351 | ||
310930c1 UD |
352 | _dl_skip_args += 2; |
353 | _dl_argc -= 2; | |
354 | _dl_argv += 2; | |
355 | } | |
b0a01055 | 356 | else if (! strcmp (_dl_argv[1], "--inhibit-rpath") && _dl_argc > 2) |
310930c1 | 357 | { |
b0a01055 | 358 | _dl_inhibit_rpath = _dl_argv[2]; |
310930c1 | 359 | |
880f421f UD |
360 | _dl_skip_args += 2; |
361 | _dl_argc -= 2; | |
362 | _dl_argv += 2; | |
363 | } | |
fd26970f UD |
364 | else |
365 | break; | |
d66e34cd | 366 | |
61eb22d3 UD |
367 | /* If we have no further argument the program was called incorrectly. |
368 | Grant the user some education. */ | |
369 | if (_dl_argc < 2) | |
370 | _dl_sysdep_fatal ("\ | |
2bcf29ba | 371 | Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\ |
61eb22d3 UD |
372 | You have invoked `ld.so', the helper program for shared library executables.\n\ |
373 | This program usually lives in the file `/lib/ld.so', and special directives\n\ | |
374 | in executable files using ELF shared libraries tell the system's program\n\ | |
375 | loader to load the helper program from this file. This helper program loads\n\ | |
376 | the shared libraries needed by the program executable, prepares the program\n\ | |
377 | to run, and runs it. You may invoke this helper program directly from the\n\ | |
378 | command line to load and run an ELF executable file; this is like executing\n\ | |
379 | that file itself, but always uses this helper program from the file you\n\ | |
380 | specified, instead of the helper program file specified in the executable\n\ | |
381 | file you run. This is mostly of use for maintainers to test new versions\n\ | |
2bcf29ba UD |
382 | of this helper program; chances are you did not intend to run this program.\n\ |
383 | \n\ | |
b0a01055 UD |
384 | --list list all dependencies and how they are resolved\n\ |
385 | --verify verify that given object really is a dynamically linked\n\ | |
386 | object we get handle\n\ | |
387 | --library-path PATH use given PATH instead of content of the environment\n\ | |
388 | variable LD_LIBRARY_PATH\n\ | |
389 | --inhibit-rpath LIST ignore RPATH information in object names in LIST\n", | |
61eb22d3 UD |
390 | NULL); |
391 | ||
0200214b RM |
392 | ++_dl_skip_args; |
393 | --_dl_argc; | |
394 | ++_dl_argv; | |
91f62ce6 | 395 | |
da832465 UD |
396 | /* Initialize the data structures for the search paths for shared |
397 | objects. */ | |
398 | _dl_init_paths (library_path); | |
5aa8ff62 | 399 | paths_initialized = 1; |
da832465 | 400 | |
2de99474 UD |
401 | if (mode == verify) |
402 | { | |
dcf0671d | 403 | char *err_str = NULL; |
993b3242 | 404 | struct map_args args; |
2de99474 | 405 | |
993b3242 | 406 | args.str = _dl_argv[0]; |
8d9618b7 | 407 | (void) _dl_catch_error (&err_str, map_doit, &args); |
2de99474 | 408 | if (err_str != NULL) |
dcf0671d UD |
409 | { |
410 | free (err_str); | |
411 | _exit (EXIT_FAILURE); | |
412 | } | |
2de99474 UD |
413 | } |
414 | else | |
87c812c2 | 415 | _dl_map_object (NULL, _dl_argv[0], 0, lt_library, 0); |
2de99474 | 416 | |
be935610 UD |
417 | phdr = _dl_loaded->l_phdr; |
418 | phent = _dl_loaded->l_phnum; | |
143e2b96 UD |
419 | /* We overwrite here a pointer to a malloc()ed string. But since |
420 | the malloc() implementation used at this point is the dummy | |
421 | implementations which has no real free() function it does not | |
422 | makes sense to free the old string first. */ | |
be935610 UD |
423 | _dl_loaded->l_name = (char *) ""; |
424 | *user_entry = _dl_loaded->l_entry; | |
0200214b RM |
425 | } |
426 | else | |
427 | { | |
428 | /* Create a link_map for the executable itself. | |
429 | This will be what dlopen on "" returns. */ | |
87c812c2 | 430 | _dl_new_object ((char *) "", "", lt_executable, NULL); |
be935610 | 431 | if (_dl_loaded == NULL) |
762a2918 | 432 | _dl_sysdep_fatal ("cannot allocate memory for link map\n", NULL); |
be935610 UD |
433 | _dl_loaded->l_phdr = phdr; |
434 | _dl_loaded->l_phnum = phent; | |
435 | _dl_loaded->l_entry = *user_entry; | |
436 | _dl_loaded->l_opencount = 1; | |
da832465 | 437 | |
97a51d8a UD |
438 | /* We delay initializing the path structure until we got the dynamic |
439 | information for the program. */ | |
0200214b RM |
440 | } |
441 | ||
052b6a6c | 442 | /* It is not safe to load stuff after the main program. */ |
be935610 | 443 | _dl_loaded->l_map_end = ~0; |
052b6a6c | 444 | /* Perhaps the executable has no PT_LOAD header entries at all. */ |
be935610 | 445 | _dl_loaded->l_map_start = ~0; |
052b6a6c | 446 | |
0200214b RM |
447 | /* Scan the program header table for the dynamic section. */ |
448 | for (ph = phdr; ph < &phdr[phent]; ++ph) | |
449 | switch (ph->p_type) | |
450 | { | |
da832465 UD |
451 | case PT_PHDR: |
452 | /* Find out the load address. */ | |
be935610 | 453 | _dl_loaded->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr; |
da832465 | 454 | break; |
0200214b RM |
455 | case PT_DYNAMIC: |
456 | /* This tells us where to find the dynamic section, | |
457 | which tells us everything we need to do. */ | |
be935610 | 458 | _dl_loaded->l_ld = (void *) _dl_loaded->l_addr + ph->p_vaddr; |
0200214b RM |
459 | break; |
460 | case PT_INTERP: | |
461 | /* This "interpreter segment" was used by the program loader to | |
462 | find the program interpreter, which is this program itself, the | |
463 | dynamic linker. We note what name finds us, so that a future | |
464 | dlopen call or DT_NEEDED entry, for something that wants to link | |
465 | against the dynamic linker as a shared library, will know that | |
466 | the shared object is already loaded. */ | |
be935610 UD |
467 | _dl_rtld_libname.name = ((const char *) _dl_loaded->l_addr |
468 | + ph->p_vaddr); | |
c84142e8 UD |
469 | _dl_rtld_libname.next = NULL; |
470 | _dl_rtld_map.l_libname = &_dl_rtld_libname; | |
f41c8091 UD |
471 | |
472 | /* Ordinarilly, we would get additional names for the loader from | |
473 | our DT_SONAME. This can't happen if we were actually linked as | |
474 | a static executable (detect this case when we have no DYNAMIC). | |
475 | If so, assume the filename component of the interpreter path to | |
476 | be our SONAME, and add it to our name list. */ | |
477 | if (_dl_rtld_map.l_ld == NULL) | |
478 | { | |
479 | char *p = strrchr (_dl_rtld_libname.name, '/'); | |
480 | if (p) | |
481 | { | |
482 | _dl_rtld_libname2.name = p+1; | |
483 | _dl_rtld_libname2.next = NULL; | |
484 | _dl_rtld_libname.next = &_dl_rtld_libname2; | |
485 | } | |
486 | } | |
487 | ||
2f6d1f1b | 488 | has_interp = 1; |
0200214b | 489 | break; |
052b6a6c UD |
490 | case PT_LOAD: |
491 | /* Remember where the main program starts in memory. */ | |
492 | { | |
493 | ElfW(Addr) mapstart; | |
be935610 UD |
494 | mapstart = _dl_loaded->l_addr + (ph->p_vaddr & ~(ph->p_align - 1)); |
495 | if (_dl_loaded->l_map_start > mapstart) | |
496 | _dl_loaded->l_map_start = mapstart; | |
052b6a6c UD |
497 | } |
498 | break; | |
0200214b | 499 | } |
ffee1316 | 500 | if (! _dl_rtld_map.l_libname && _dl_rtld_map.l_name) |
c84142e8 UD |
501 | { |
502 | /* We were invoked directly, so the program might not have a | |
503 | PT_INTERP. */ | |
504 | _dl_rtld_libname.name = _dl_rtld_map.l_name; | |
505 | _dl_rtld_libname.next = NULL; | |
506 | _dl_rtld_map.l_libname = &_dl_rtld_libname; | |
507 | } | |
ffee1316 RM |
508 | else |
509 | assert (_dl_rtld_map.l_libname); /* How else did we get here? */ | |
0200214b RM |
510 | |
511 | /* Extract the contents of the dynamic section for easy access. */ | |
be935610 UD |
512 | elf_get_dynamic_info (_dl_loaded->l_ld, _dl_loaded->l_info); |
513 | if (_dl_loaded->l_info[DT_HASH]) | |
0200214b | 514 | /* Set up our cache of pointers into the hash table. */ |
be935610 | 515 | _dl_setup_hash (_dl_loaded); |
0200214b | 516 | |
e2102c14 UD |
517 | if (mode == verify) |
518 | { | |
519 | /* We were called just to verify that this is a dynamic | |
520 | executable using us as the program interpreter. Exit with an | |
521 | error if we were not able to load the binary or no interpreter | |
522 | is specified (i.e., this is no dynamically linked binary. */ | |
be935610 | 523 | if (_dl_loaded->l_ld == NULL) |
e2102c14 | 524 | _exit (1); |
e2102c14 UD |
525 | |
526 | /* We allow here some platform specific code. */ | |
527 | #ifdef DISTINGUISH_LIB_VERSIONS | |
528 | DISTINGUISH_LIB_VERSIONS; | |
529 | #endif | |
eb406346 | 530 | _exit (has_interp ? 0 : 2); |
e2102c14 UD |
531 | } |
532 | ||
5aa8ff62 | 533 | if (! paths_initialized) |
97a51d8a UD |
534 | /* Initialize the data structures for the search paths for shared |
535 | objects. */ | |
120b4c49 | 536 | _dl_init_paths (library_path); |
97a51d8a | 537 | |
0200214b | 538 | /* Put the link_map for ourselves on the chain so it can be found by |
ceb2d9aa | 539 | name. Note that at this point the global chain of link maps contains |
be935610 | 540 | exactly one element, which is pointed to by _dl_loaded. */ |
ffee1316 RM |
541 | if (! _dl_rtld_map.l_name) |
542 | /* If not invoked directly, the dynamic linker shared object file was | |
543 | found by the PT_INTERP name. */ | |
c84142e8 | 544 | _dl_rtld_map.l_name = (char *) _dl_rtld_map.l_libname->name; |
ba79d61b | 545 | _dl_rtld_map.l_type = lt_library; |
be935610 UD |
546 | _dl_loaded->l_next = &_dl_rtld_map; |
547 | _dl_rtld_map.l_prev = _dl_loaded; | |
0200214b | 548 | |
14bab8de UD |
549 | /* We have two ways to specify objects to preload: via environment |
550 | variable and via the file /etc/ld.so.preload. The later can also | |
551 | be used when security is enabled. */ | |
2064087b RM |
552 | preloads = NULL; |
553 | npreloads = 0; | |
14bab8de | 554 | |
fd26970f | 555 | if (preloadlist) |
c4029823 | 556 | { |
566efee2 UD |
557 | /* The LD_PRELOAD environment variable gives list of libraries |
558 | separated by white space or colons that are loaded before the | |
fd26970f UD |
559 | executable's dependencies and prepended to the global scope |
560 | list. If the binary is running setuid all elements | |
561 | containing a '/' are ignored since it is insecure. */ | |
562 | char *list = strdupa (preloadlist); | |
563 | char *p; | |
566efee2 | 564 | while ((p = strsep (&list, " :")) != NULL) |
e2102c14 UD |
565 | if (p[0] != '\0' |
566 | && (! __libc_enable_secure || strchr (p, '/') == NULL)) | |
fd26970f | 567 | { |
be935610 | 568 | struct link_map *new_map = _dl_map_object (_dl_loaded, p, 1, |
c6222ab9 | 569 | lt_library, 0); |
bd355af0 UD |
570 | if (new_map->l_opencount == 1) |
571 | /* It is no duplicate. */ | |
572 | ++npreloads; | |
fd26970f | 573 | } |
c4029823 UD |
574 | } |
575 | ||
14bab8de UD |
576 | /* Read the contents of the file. */ |
577 | file = _dl_sysdep_read_whole_file ("/etc/ld.so.preload", &file_size, | |
578 | PROT_READ | PROT_WRITE); | |
579 | if (file) | |
580 | { | |
581 | /* Parse the file. It contains names of libraries to be loaded, | |
582 | separated by white spaces or `:'. It may also contain | |
583 | comments introduced by `#'. */ | |
584 | char *problem; | |
585 | char *runp; | |
586 | size_t rest; | |
587 | ||
588 | /* Eliminate comments. */ | |
589 | runp = file; | |
590 | rest = file_size; | |
591 | while (rest > 0) | |
592 | { | |
593 | char *comment = memchr (runp, '#', rest); | |
594 | if (comment == NULL) | |
595 | break; | |
596 | ||
597 | rest -= comment - runp; | |
598 | do | |
599 | *comment = ' '; | |
600 | while (--rest > 0 && *++comment != '\n'); | |
601 | } | |
602 | ||
603 | /* We have one problematic case: if we have a name at the end of | |
604 | the file without a trailing terminating characters, we cannot | |
605 | place the \0. Handle the case separately. */ | |
49891c10 UD |
606 | if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t' |
607 | && file[file_size - 1] != '\n' && file[file_size - 1] != ':') | |
14bab8de UD |
608 | { |
609 | problem = &file[file_size]; | |
610 | while (problem > file && problem[-1] != ' ' && problem[-1] != '\t' | |
49891c10 | 611 | && problem[-1] != '\n' && problem[-1] != ':') |
14bab8de UD |
612 | --problem; |
613 | ||
614 | if (problem > file) | |
615 | problem[-1] = '\0'; | |
616 | } | |
617 | else | |
49891c10 UD |
618 | { |
619 | problem = NULL; | |
620 | file[file_size - 1] = '\0'; | |
621 | } | |
14bab8de UD |
622 | |
623 | if (file != problem) | |
624 | { | |
625 | char *p; | |
e2102c14 | 626 | runp = file; |
14bab8de | 627 | while ((p = strsep (&runp, ": \t\n")) != NULL) |
e2102c14 UD |
628 | if (p[0] != '\0') |
629 | { | |
be935610 | 630 | struct link_map *new_map = _dl_map_object (_dl_loaded, p, 1, |
e2102c14 UD |
631 | lt_library, 0); |
632 | if (new_map->l_opencount == 1) | |
633 | /* It is no duplicate. */ | |
634 | ++npreloads; | |
635 | } | |
14bab8de UD |
636 | } |
637 | ||
638 | if (problem != NULL) | |
639 | { | |
640 | char *p = strndupa (problem, file_size - (problem - file)); | |
be935610 | 641 | struct link_map *new_map = _dl_map_object (_dl_loaded, p, 1, |
c6222ab9 | 642 | lt_library, 0); |
bd355af0 UD |
643 | if (new_map->l_opencount == 1) |
644 | /* It is no duplicate. */ | |
645 | ++npreloads; | |
14bab8de UD |
646 | } |
647 | ||
648 | /* We don't need the file anymore. */ | |
649 | __munmap (file, file_size); | |
650 | } | |
651 | ||
14bab8de UD |
652 | if (npreloads != 0) |
653 | { | |
654 | /* Set up PRELOADS with a vector of the preloaded libraries. */ | |
655 | struct link_map *l; | |
14bab8de UD |
656 | preloads = __alloca (npreloads * sizeof preloads[0]); |
657 | l = _dl_rtld_map.l_next; /* End of the chain before preloads. */ | |
658 | i = 0; | |
659 | do | |
660 | { | |
661 | preloads[i++] = l; | |
662 | l = l->l_next; | |
663 | } while (l); | |
664 | assert (i == npreloads); | |
665 | } | |
666 | ||
2064087b RM |
667 | /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD |
668 | specified some libraries to load, these are inserted before the actual | |
669 | dependencies in the executable's searchlist for symbol resolution. */ | |
e3e35cfc UD |
670 | _dl_map_object_deps (_dl_loaded, preloads, npreloads, mode == trace, 0); |
671 | ||
672 | /* Mark all objects as being in the global scope. */ | |
673 | for (i = _dl_loaded->l_searchlist.r_nlist; i > 0; ) | |
674 | _dl_loaded->l_searchlist.r_list[--i]->l_global = 1; | |
d66e34cd | 675 | |
2064087b | 676 | #ifndef MAP_ANON |
f332db02 RM |
677 | /* We are done mapping things, so close the zero-fill descriptor. */ |
678 | __close (_dl_zerofd); | |
679 | _dl_zerofd = -1; | |
2064087b | 680 | #endif |
f332db02 | 681 | |
f9496a7b RM |
682 | /* Remove _dl_rtld_map from the chain. */ |
683 | _dl_rtld_map.l_prev->l_next = _dl_rtld_map.l_next; | |
684 | if (_dl_rtld_map.l_next) | |
685 | _dl_rtld_map.l_next->l_prev = _dl_rtld_map.l_prev; | |
686 | ||
eb406346 | 687 | if (_dl_rtld_map.l_opencount > 1) |
0200214b | 688 | { |
f9496a7b RM |
689 | /* Some DT_NEEDED entry referred to the interpreter object itself, so |
690 | put it back in the list of visible objects. We insert it into the | |
691 | chain in symbol search order because gdb uses the chain's order as | |
692 | its symbol search order. */ | |
77aba05b | 693 | i = 1; |
be935610 | 694 | while (_dl_loaded->l_searchlist.r_list[i] != &_dl_rtld_map) |
f9496a7b | 695 | ++i; |
be935610 UD |
696 | _dl_rtld_map.l_prev = _dl_loaded->l_searchlist.r_list[i - 1]; |
697 | _dl_rtld_map.l_next = (i + 1 < _dl_loaded->l_searchlist.r_nlist | |
698 | ? _dl_loaded->l_searchlist.r_list[i + 1] | |
699 | : NULL); | |
f9496a7b RM |
700 | assert (_dl_rtld_map.l_prev->l_next == _dl_rtld_map.l_next); |
701 | _dl_rtld_map.l_prev->l_next = &_dl_rtld_map; | |
4d02a5b1 | 702 | if (_dl_rtld_map.l_next) |
f9496a7b RM |
703 | { |
704 | assert (_dl_rtld_map.l_next->l_prev == _dl_rtld_map.l_prev); | |
705 | _dl_rtld_map.l_next->l_prev = &_dl_rtld_map; | |
706 | } | |
0200214b | 707 | } |
d66e34cd | 708 | |
c84142e8 UD |
709 | /* Now let us see whether all libraries are available in the |
710 | versions we need. */ | |
711 | { | |
993b3242 UD |
712 | struct version_check_args args; |
713 | args.doexit = mode == normal; | |
993b3242 | 714 | _dl_receive_error (print_missing_version, version_check_doit, &args); |
c84142e8 UD |
715 | } |
716 | ||
2de99474 | 717 | if (mode != normal) |
0200214b RM |
718 | { |
719 | /* We were run just to list the shared libraries. It is | |
720 | important that we do this before real relocation, because the | |
721 | functions we call below for output may no longer work properly | |
722 | after relocation. */ | |
0200214b RM |
723 | if (! _dl_loaded->l_info[DT_NEEDED]) |
724 | _dl_sysdep_message ("\t", "statically linked\n", NULL); | |
725 | else | |
ceb2d9aa UD |
726 | { |
727 | struct link_map *l; | |
728 | ||
729 | for (l = _dl_loaded->l_next; l; l = l->l_next) | |
730 | if (l->l_opencount == 0) | |
731 | /* The library was not found. */ | |
732 | _dl_sysdep_message ("\t", l->l_libname->name, " => not found\n", | |
733 | NULL); | |
734 | else | |
735 | { | |
736 | char buf[20], *bp; | |
737 | buf[sizeof buf - 1] = '\0'; | |
af6f3906 | 738 | bp = _itoa_word (l->l_addr, &buf[sizeof buf - 1], 16, 0); |
ceb2d9aa UD |
739 | while ((size_t) (&buf[sizeof buf - 1] - bp) |
740 | < sizeof l->l_addr * 2) | |
741 | *--bp = '0'; | |
742 | _dl_sysdep_message ("\t", l->l_libname->name, " => ", | |
743 | l->l_name, " (0x", bp, ")\n", NULL); | |
744 | } | |
745 | } | |
1a3a58fd | 746 | |
2de99474 | 747 | if (mode != trace) |
cddcfecf RM |
748 | for (i = 1; i < _dl_argc; ++i) |
749 | { | |
750 | const ElfW(Sym) *ref = NULL; | |
751 | ElfW(Addr) loadbase = _dl_lookup_symbol (_dl_argv[i], &ref, | |
be935610 | 752 | _dl_loaded->l_scope, |
dcf0671d | 753 | "argument", |
a2b08ee5 | 754 | ELF_MACHINE_JMP_SLOT); |
cddcfecf RM |
755 | char buf[20], *bp; |
756 | buf[sizeof buf - 1] = '\0'; | |
af6f3906 | 757 | bp = _itoa_word (ref->st_value, &buf[sizeof buf - 1], 16, 0); |
14bab8de | 758 | while ((size_t) (&buf[sizeof buf - 1] - bp) < sizeof loadbase * 2) |
cddcfecf RM |
759 | *--bp = '0'; |
760 | _dl_sysdep_message (_dl_argv[i], " found at 0x", bp, NULL); | |
761 | buf[sizeof buf - 1] = '\0'; | |
af6f3906 | 762 | bp = _itoa_word (loadbase, &buf[sizeof buf - 1], 16, 0); |
14bab8de | 763 | while ((size_t) (&buf[sizeof buf - 1] - bp) < sizeof loadbase * 2) |
cddcfecf RM |
764 | *--bp = '0'; |
765 | _dl_sysdep_message (" in object at 0x", bp, "\n", NULL); | |
766 | } | |
ce37fa88 | 767 | else |
fd26970f | 768 | { |
ce37fa88 UD |
769 | if (lazy >= 0) |
770 | { | |
771 | /* We have to do symbol dependency testing. */ | |
772 | struct relocate_args args; | |
773 | struct link_map *l; | |
993b3242 | 774 | |
ce37fa88 | 775 | args.lazy = lazy; |
fd26970f | 776 | |
ce37fa88 UD |
777 | l = _dl_loaded; |
778 | while (l->l_next) | |
779 | l = l->l_next; | |
780 | do | |
781 | { | |
782 | if (l != &_dl_rtld_map && l->l_opencount > 0) | |
783 | { | |
784 | args.l = l; | |
785 | _dl_receive_error (print_unresolved, relocate_doit, | |
786 | &args); | |
ce37fa88 UD |
787 | } |
788 | l = l->l_prev; | |
789 | } while (l); | |
790 | } | |
791 | ||
792 | #define VERNEEDTAG (DT_NUM + DT_PROCNUM + DT_VERSIONTAGIDX (DT_VERNEED)) | |
120b4c49 | 793 | if (version_info) |
fd26970f | 794 | { |
ce37fa88 UD |
795 | /* Print more information. This means here, print information |
796 | about the versions needed. */ | |
797 | int first = 1; | |
798 | struct link_map *map = _dl_loaded; | |
799 | ||
800 | for (map = _dl_loaded; map != NULL; map = map->l_next) | |
fd26970f | 801 | { |
f41c8091 | 802 | const char *strtab; |
ce37fa88 | 803 | ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG]; |
f41c8091 UD |
804 | ElfW(Verneed) *ent; |
805 | ||
806 | if (dyn == NULL) | |
807 | continue; | |
808 | ||
809 | strtab = (const char *) | |
810 | (map->l_addr + map->l_info[DT_STRTAB]->d_un.d_ptr); | |
811 | ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr); | |
ce37fa88 | 812 | |
f41c8091 | 813 | if (first) |
ce37fa88 | 814 | { |
f41c8091 UD |
815 | _dl_sysdep_message ("\n\tVersion information:\n", NULL); |
816 | first = 0; | |
817 | } | |
ce37fa88 | 818 | |
f41c8091 UD |
819 | _dl_sysdep_message ("\t", (map->l_name[0] |
820 | ? map->l_name : _dl_argv[0]), | |
821 | ":\n", NULL); | |
822 | ||
823 | while (1) | |
824 | { | |
825 | ElfW(Vernaux) *aux; | |
826 | struct link_map *needed; | |
ce37fa88 | 827 | |
f41c8091 UD |
828 | needed = find_needed (strtab + ent->vn_file); |
829 | aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux); | |
ce37fa88 UD |
830 | |
831 | while (1) | |
832 | { | |
f41c8091 UD |
833 | const char *fname = NULL; |
834 | ||
835 | _dl_sysdep_message ("\t\t", | |
836 | strtab + ent->vn_file, | |
837 | " (", strtab + aux->vna_name, | |
838 | ") ", | |
839 | (aux->vna_flags | |
840 | & VER_FLG_WEAK | |
841 | ? "[WEAK] " : ""), | |
842 | "=> ", NULL); | |
843 | ||
844 | if (needed != NULL | |
845 | && match_version (strtab+aux->vna_name, needed)) | |
846 | fname = needed->l_name; | |
847 | ||
848 | _dl_sysdep_message (fname ?: "not found", "\n", | |
849 | NULL); | |
ce37fa88 | 850 | |
f41c8091 UD |
851 | if (aux->vna_next == 0) |
852 | /* No more symbols. */ | |
ce37fa88 UD |
853 | break; |
854 | ||
f41c8091 UD |
855 | /* Next symbol. */ |
856 | aux = (ElfW(Vernaux) *) ((char *) aux | |
857 | + aux->vna_next); | |
ce37fa88 | 858 | } |
f41c8091 UD |
859 | |
860 | if (ent->vn_next == 0) | |
861 | /* No more dependencies. */ | |
862 | break; | |
863 | ||
864 | /* Next dependency. */ | |
865 | ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next); | |
ce37fa88 | 866 | } |
fd26970f | 867 | } |
ce37fa88 | 868 | } |
fd26970f | 869 | } |
d66e34cd | 870 | |
0200214b RM |
871 | _exit (0); |
872 | } | |
86d2c878 | 873 | |
ba79d61b RM |
874 | { |
875 | /* Now we have all the objects loaded. Relocate them all except for | |
876 | the dynamic linker itself. We do this in reverse order so that copy | |
877 | relocs of earlier objects overwrite the data written by later | |
878 | objects. We do not re-relocate the dynamic linker itself in this | |
879 | loop because that could result in the GOT entries for functions we | |
880 | call being changed, and that would break us. It is safe to relocate | |
881 | the dynamic linker out of order because it has no copy relocs (we | |
882 | know that because it is self-contained). */ | |
883 | ||
ceb2d9aa | 884 | struct link_map *l; |
c0fb8a56 UD |
885 | int consider_profiling = _dl_profile != NULL; |
886 | ||
887 | /* If we are profiling we also must do lazy reloaction. */ | |
888 | lazy |= consider_profiling; | |
889 | ||
ba79d61b RM |
890 | l = _dl_loaded; |
891 | while (l->l_next) | |
892 | l = l->l_next; | |
893 | do | |
894 | { | |
895 | if (l != &_dl_rtld_map) | |
be935610 UD |
896 | _dl_relocate_object (l, l->l_scope, lazy, consider_profiling); |
897 | ||
ba79d61b RM |
898 | l = l->l_prev; |
899 | } while (l); | |
900 | ||
901 | /* Do any necessary cleanups for the startup OS interface code. | |
902 | We do these now so that no calls are made after rtld re-relocation | |
903 | which might be resolved to different functions than we expect. | |
904 | We cannot do this before relocating the other objects because | |
905 | _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */ | |
906 | _dl_sysdep_start_cleanup (); | |
907 | ||
908 | if (_dl_rtld_map.l_opencount > 0) | |
909 | /* There was an explicit ref to the dynamic linker as a shared lib. | |
910 | Re-relocate ourselves with user-controlled symbol definitions. */ | |
be935610 | 911 | _dl_relocate_object (&_dl_rtld_map, _dl_loaded->l_scope, 0, 0); |
ba79d61b | 912 | } |
ac16e905 | 913 | |
be935610 UD |
914 | /* Now set up the variable which helps the assembler startup code. */ |
915 | _dl_main_searchlist = &_dl_loaded->l_searchlist; | |
916 | _dl_global_scope[0] = &_dl_loaded->l_searchlist; | |
917 | ||
604510f7 UD |
918 | /* Safe the information about the original global scope list since |
919 | we need it in the memory handling later. */ | |
920 | _dl_initial_searchlist = *_dl_main_searchlist; | |
921 | ||
4d6acc61 RM |
922 | { |
923 | /* Initialize _r_debug. */ | |
924 | struct r_debug *r = _dl_debug_initialize (_dl_rtld_map.l_addr); | |
ceb2d9aa | 925 | struct link_map *l; |
4d6acc61 RM |
926 | |
927 | l = _dl_loaded; | |
ec42724d RM |
928 | |
929 | #ifdef ELF_MACHINE_DEBUG_SETUP | |
930 | ||
931 | /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */ | |
932 | ||
933 | ELF_MACHINE_DEBUG_SETUP (l, r); | |
934 | ELF_MACHINE_DEBUG_SETUP (&_dl_rtld_map, r); | |
935 | ||
936 | #else | |
937 | ||
4d6acc61 RM |
938 | if (l->l_info[DT_DEBUG]) |
939 | /* There is a DT_DEBUG entry in the dynamic section. Fill it in | |
940 | with the run-time address of the r_debug structure */ | |
941 | l->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r; | |
942 | ||
d746b89c RM |
943 | /* Fill in the pointer in the dynamic linker's own dynamic section, in |
944 | case you run gdb on the dynamic linker directly. */ | |
945 | if (_dl_rtld_map.l_info[DT_DEBUG]) | |
946 | _dl_rtld_map.l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r; | |
947 | ||
ec42724d RM |
948 | #endif |
949 | ||
4d6acc61 RM |
950 | /* Notify the debugger that all objects are now mapped in. */ |
951 | r->r_state = RT_ADD; | |
952 | _dl_debug_state (); | |
953 | } | |
0200214b | 954 | |
08cac4ac UD |
955 | #ifndef MAP_COPY |
956 | /* We must munmap() the cache file. */ | |
957 | _dl_unload_cache (); | |
958 | #endif | |
959 | ||
3996f34b UD |
960 | /* Now enable profiling if needed. */ |
961 | if (_dl_profile_map != NULL) | |
962 | /* We must prepare the profiling. */ | |
963 | _dl_start_profile (_dl_profile_map, _dl_profile_output); | |
964 | ||
d66e34cd RM |
965 | /* Once we return, _dl_sysdep_start will invoke |
966 | the DT_INIT functions and then *USER_ENTRY. */ | |
967 | } | |
fd26970f UD |
968 | \f |
969 | /* This is a little helper function for resolving symbols while | |
970 | tracing the binary. */ | |
971 | static void | |
c84142e8 UD |
972 | print_unresolved (int errcode __attribute__ ((unused)), const char *objname, |
973 | const char *errstring) | |
fd26970f | 974 | { |
3996f34b UD |
975 | if (objname[0] == '\0') |
976 | objname = _dl_argv[0] ?: "<main program>"; | |
fd26970f UD |
977 | _dl_sysdep_error (errstring, " (", objname, ")\n", NULL); |
978 | } | |
c84142e8 UD |
979 | \f |
980 | /* This is a little helper function for resolving symbols while | |
981 | tracing the binary. */ | |
982 | static void | |
983 | print_missing_version (int errcode __attribute__ ((unused)), | |
984 | const char *objname, const char *errstring) | |
985 | { | |
986 | _dl_sysdep_error (_dl_argv[0] ?: "<program name unknown>", ": ", | |
987 | objname, ": ", errstring, "\n", NULL); | |
988 | } | |
ea278354 | 989 | \f |
7dea968e UD |
990 | /* Nonzero if any of the debugging options is enabled. */ |
991 | static int any_debug; | |
992 | ||
b5efde2f UD |
993 | /* Process the string given as the parameter which explains which debugging |
994 | options are enabled. */ | |
995 | static void | |
14c44e2e | 996 | process_dl_debug (const char *dl_debug) |
b5efde2f | 997 | { |
14c44e2e UD |
998 | size_t len; |
999 | #define separators " ,:" | |
b5efde2f UD |
1000 | do |
1001 | { | |
14c44e2e | 1002 | len = 0; |
b5efde2f | 1003 | /* Skip separating white spaces and commas. */ |
14c44e2e | 1004 | dl_debug += strspn (dl_debug, separators); |
b5efde2f UD |
1005 | if (*dl_debug != '\0') |
1006 | { | |
14c44e2e UD |
1007 | len = strcspn (dl_debug, separators); |
1008 | ||
1009 | switch (len) | |
b5efde2f | 1010 | { |
b0b67c47 UD |
1011 | case 3: |
1012 | /* This option is not documented since it is not generally | |
1013 | useful. */ | |
1014 | if (memcmp (dl_debug, "all", 3) == 0) | |
1015 | { | |
1016 | _dl_debug_libs = 1; | |
1017 | _dl_debug_impcalls = 1; | |
1018 | _dl_debug_reloc = 1; | |
1019 | _dl_debug_files = 1; | |
1020 | _dl_debug_symbols = 1; | |
1021 | _dl_debug_bindings = 1; | |
1022 | _dl_debug_versions = 1; | |
1023 | any_debug = 1; | |
ceb27555 | 1024 | continue; |
b0b67c47 UD |
1025 | } |
1026 | break; | |
1027 | ||
14c44e2e UD |
1028 | case 4: |
1029 | if (memcmp (dl_debug, "help", 4) == 0) | |
1030 | { | |
1031 | _dl_sysdep_message ("\ | |
08b511e6 | 1032 | Valid options for the LD_DEBUG environment variable are:\n\ |
b5efde2f | 1033 | \n\ |
0c367d92 | 1034 | bindings display information about symbol binding\n\ |
8193034b | 1035 | files display processing of files and libraries\n\ |
0c367d92 UD |
1036 | help display this help message and exit\n\ |
1037 | libs display library search paths\n\ | |
8193034b | 1038 | reloc display relocation processing\n\ |
de100ca7 | 1039 | symbols display symbol table processing\n\ |
8193034b | 1040 | versions display version dependencies\n\ |
0c367d92 UD |
1041 | \n\ |
1042 | To direct the debugging output into a file instead of standard output\n\ | |
1043 | a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n", | |
1044 | NULL); | |
14c44e2e UD |
1045 | _exit (0); |
1046 | } | |
77aba05b | 1047 | |
14c44e2e UD |
1048 | if (memcmp (dl_debug, "libs", 4) == 0) |
1049 | { | |
1050 | _dl_debug_libs = 1; | |
1051 | _dl_debug_impcalls = 1; | |
1052 | any_debug = 1; | |
1053 | continue; | |
1054 | } | |
1055 | break; | |
1056 | ||
1057 | case 5: | |
1058 | if (memcmp (dl_debug, "reloc", 5) == 0) | |
1059 | { | |
1060 | _dl_debug_reloc = 1; | |
1061 | _dl_debug_impcalls = 1; | |
1062 | any_debug = 1; | |
1063 | continue; | |
1064 | } | |
1065 | ||
1066 | if (memcmp (dl_debug, "files", 5) == 0) | |
1067 | { | |
1068 | _dl_debug_files = 1; | |
1069 | _dl_debug_impcalls = 1; | |
1070 | any_debug = 1; | |
1071 | continue; | |
1072 | } | |
1073 | break; | |
77aba05b | 1074 | |
14c44e2e UD |
1075 | case 7: |
1076 | if (memcmp (dl_debug, "symbols", 7) == 0) | |
1077 | { | |
1078 | _dl_debug_symbols = 1; | |
1079 | _dl_debug_impcalls = 1; | |
1080 | any_debug = 1; | |
1081 | continue; | |
1082 | } | |
1083 | break; | |
77aba05b | 1084 | |
14c44e2e UD |
1085 | case 8: |
1086 | if (memcmp (dl_debug, "bindings", 8) == 0) | |
1087 | { | |
1088 | _dl_debug_bindings = 1; | |
1089 | _dl_debug_impcalls = 1; | |
1090 | any_debug = 1; | |
1091 | continue; | |
1092 | } | |
1093 | ||
1094 | if (memcmp (dl_debug, "versions", 8) == 0) | |
1095 | { | |
1096 | _dl_debug_versions = 1; | |
1097 | _dl_debug_impcalls = 1; | |
1098 | any_debug = 1; | |
1099 | continue; | |
1100 | } | |
1101 | break; | |
1102 | ||
1103 | default: | |
1104 | break; | |
77aba05b | 1105 | } |
14c44e2e UD |
1106 | |
1107 | { | |
1108 | /* Display a warning and skip everything until next separator. */ | |
1109 | char *startp = strndupa (dl_debug, len); | |
1110 | _dl_sysdep_error ("warning: debug option `", startp, | |
1111 | "' unknown; try LD_DEBUG=help\n", NULL); | |
1112 | } | |
b5efde2f UD |
1113 | } |
1114 | } | |
14c44e2e | 1115 | while (*(dl_debug += len) != '\0'); |
b5efde2f UD |
1116 | } |
1117 | \f | |
ea278354 UD |
1118 | /* Process all environments variables the dynamic linker must recognize. |
1119 | Since all of them start with `LD_' we are a bit smarter while finding | |
1120 | all the entries. */ | |
1121 | static void | |
1122 | process_envvars (enum mode *modep, int *lazyp) | |
1123 | { | |
1124 | char **runp = NULL; | |
1125 | char *envline; | |
1126 | enum mode mode = normal; | |
1127 | int bind_now = 0; | |
7dea968e | 1128 | char *debug_output = NULL; |
ea278354 UD |
1129 | |
1130 | /* This is the default place for profiling data file. */ | |
1131 | _dl_profile_output = "/var/tmp"; | |
1132 | ||
1133 | while ((envline = _dl_next_ld_env_entry (&runp)) != NULL) | |
1134 | { | |
14c44e2e | 1135 | size_t len = strcspn (envline, "=") - 3; |
ea278354 | 1136 | |
14c44e2e | 1137 | switch (len) |
ea278354 | 1138 | { |
14c44e2e UD |
1139 | case 4: |
1140 | /* Warning level, verbose or not. */ | |
1141 | if (memcmp (&envline[3], "WARN", 4) == 0) | |
1142 | _dl_verbose = envline[8] != '\0'; | |
1143 | break; | |
ea278354 | 1144 | |
14c44e2e UD |
1145 | case 5: |
1146 | /* Debugging of the dynamic linker? */ | |
1147 | if (memcmp (&envline[3], "DEBUG", 5) == 0) | |
1148 | process_dl_debug (&envline[9]); | |
1149 | break; | |
b5efde2f | 1150 | |
14c44e2e UD |
1151 | case 7: |
1152 | /* Print information about versions. */ | |
1153 | if (memcmp (&envline[3], "VERBOSE", 7) == 0) | |
1154 | { | |
1155 | version_info = envline[11] != '\0'; | |
1156 | break; | |
1157 | } | |
7dea968e | 1158 | |
14c44e2e UD |
1159 | /* List of objects to be preloaded. */ |
1160 | if (memcmp (&envline[3], "PRELOAD", 7) == 0) | |
1161 | { | |
1162 | preloadlist = &envline[11]; | |
1163 | break; | |
1164 | } | |
120b4c49 | 1165 | |
14c44e2e UD |
1166 | /* Which shared object shall be profiled. */ |
1167 | if (memcmp (&envline[3], "PROFILE", 7) == 0) | |
1168 | { | |
1169 | _dl_profile = &envline[11]; | |
1170 | if (*_dl_profile == '\0') | |
1171 | _dl_profile = NULL; | |
1172 | } | |
1173 | break; | |
120b4c49 | 1174 | |
14c44e2e UD |
1175 | case 8: |
1176 | /* Do we bind early? */ | |
0e103c6d UD |
1177 | if (memcmp (&envline[3], "BIND_NOW", 8) == 0) |
1178 | bind_now = envline[12] != '\0'; | |
14c44e2e | 1179 | break; |
ea278354 | 1180 | |
14c44e2e UD |
1181 | case 9: |
1182 | /* Test whether we want to see the content of the auxiliary | |
1183 | array passed up from the kernel. */ | |
1184 | if (memcmp (&envline[3], "SHOW_AUXV", 9) == 0) | |
1185 | _dl_show_auxv (); | |
1186 | break; | |
ea278354 | 1187 | |
12264bd7 | 1188 | case 10: |
3081378b | 1189 | /* Mask for the important hardware capabilities. */ |
12264bd7 UD |
1190 | if (memcmp (&envline[3], "HWCAP_MASK", 10) == 0) |
1191 | _dl_hwcap_mask = strtoul (&envline[14], NULL, 0); | |
1192 | break; | |
1193 | ||
f787edde UD |
1194 | case 11: |
1195 | /* Path where the binary is found. */ | |
45769315 UD |
1196 | if (!__libc_enable_secure |
1197 | && memcmp (&envline[3], "ORIGIN_PATH", 11) == 0) | |
997a4165 | 1198 | _dl_origin_path = &envline[15]; |
f787edde UD |
1199 | break; |
1200 | ||
14c44e2e UD |
1201 | case 12: |
1202 | /* Where to place the profiling data file. */ | |
1203 | if (memcmp (&envline[3], "DEBUG_OUTPUT", 12) == 0) | |
1204 | { | |
1205 | debug_output = &envline[16]; | |
1206 | break; | |
1207 | } | |
ea278354 | 1208 | |
14c44e2e UD |
1209 | /* The library search path. */ |
1210 | if (memcmp (&envline[3], "LIBRARY_PATH", 12) == 0) | |
1211 | library_path = &envline[16]; | |
1212 | break; | |
ea278354 | 1213 | |
14c44e2e UD |
1214 | case 14: |
1215 | /* Where to place the profiling data file. */ | |
3081378b UD |
1216 | if (!__libc_enable_secure |
1217 | && memcmp (&envline[3], "PROFILE_OUTPUT", 14) == 0) | |
14c44e2e UD |
1218 | { |
1219 | _dl_profile_output = &envline[18]; | |
1220 | if (*_dl_profile_output == '\0') | |
1221 | _dl_profile_output = "/var/tmp"; | |
1222 | } | |
1223 | break; | |
120b4c49 | 1224 | |
14c44e2e UD |
1225 | case 20: |
1226 | /* The mode of the dynamic linker can be set. */ | |
1227 | if (memcmp (&envline[3], "TRACE_LOADED_OBJECTS", 20) == 0) | |
1228 | mode = trace; | |
1229 | break; | |
e2102c14 UD |
1230 | |
1231 | /* We might have some extra environment variable to handle. This | |
1232 | is tricky due to the pre-processing of the length of the name | |
1233 | in the switch statement here. The code here assumes that added | |
1234 | environment variables have a different length. */ | |
1235 | #ifdef EXTRA_LD_ENVVARS | |
1236 | EXTRA_LD_ENVVARS | |
1237 | #endif | |
ea278354 UD |
1238 | } |
1239 | } | |
1240 | ||
4bae5567 UD |
1241 | /* Extra security for SUID binaries. Remove all dangerous environment |
1242 | variables. */ | |
1243 | if (__libc_enable_secure) | |
1244 | { | |
1245 | static const char *unsecure_envvars[] = | |
1246 | { | |
1247 | #ifdef EXTRA_UNSECURE_ENVVARS | |
1248 | EXTRA_UNSECURE_ENVVARS | |
1249 | #endif | |
1250 | }; | |
1251 | size_t cnt; | |
1252 | ||
1253 | if (preloadlist != NULL) | |
1254 | unsetenv ("LD_PRELOAD"); | |
1255 | if (library_path != NULL) | |
1256 | unsetenv ("LD_LIBRARY_PATH"); | |
1257 | ||
1258 | for (cnt = 0; | |
1259 | cnt < sizeof (unsecure_envvars) / sizeof (unsecure_envvars[0]); | |
1260 | ++cnt) | |
1261 | unsetenv (unsecure_envvars[cnt]); | |
1262 | } | |
1263 | ||
7dea968e UD |
1264 | /* If we have to run the dynamic linker in debugging mode and the |
1265 | LD_DEBUG_OUTPUT environment variable is given, we write the debug | |
1266 | messages to this file. */ | |
14c44e2e | 1267 | if (any_debug && debug_output != NULL && !__libc_enable_secure) |
7dea968e | 1268 | { |
7a2fd787 UD |
1269 | size_t name_len = strlen (debug_output); |
1270 | char buf[name_len + 12]; | |
1271 | char *startp; | |
1272 | ||
1273 | buf[name_len + 11] = '\0'; | |
1274 | startp = _itoa_word (__getpid (), &buf[name_len + 11], 10, 0); | |
1275 | *--startp = '.'; | |
1276 | startp = memcpy (startp - name_len, debug_output, name_len); | |
1277 | ||
1278 | _dl_debug_fd = __open (startp, O_WRONLY | O_APPEND | O_CREAT, 0666); | |
7dea968e UD |
1279 | if (_dl_debug_fd == -1) |
1280 | /* We use standard output if opening the file failed. */ | |
1281 | _dl_debug_fd = STDOUT_FILENO; | |
1282 | } | |
1283 | ||
ea278354 UD |
1284 | /* LAZY is determined by the environment variable LD_WARN and |
1285 | LD_BIND_NOW if we trace the binary. */ | |
1286 | if (mode == trace) | |
1287 | *lazyp = _dl_verbose ? !bind_now : -1; | |
1288 | else | |
1289 | *lazyp = !__libc_enable_secure && !bind_now; | |
1290 | ||
1291 | *modep = mode; | |
1292 | } |