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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 <link.h> |
d66e34cd RM |
22 | #include <stddef.h> |
23 | #include <stdlib.h> | |
f51d1dfd | 24 | #include <string.h> |
d66e34cd | 25 | #include <unistd.h> |
2064087b | 26 | #include <sys/mman.h> /* Check if MAP_ANON is defined. */ |
ce37fa88 | 27 | #include <stdio-common/_itoa.h> |
b1dbbaa4 | 28 | #include <assert.h> |
f21acc89 | 29 | #include <entry.h> |
f5348425 RM |
30 | #include "dynamic-link.h" |
31 | ||
32 | ||
d66e34cd RM |
33 | /* System-specific function to do initial startup for the dynamic linker. |
34 | After this, file access calls and getenv must work. This is responsible | |
cddcfecf | 35 | for setting __libc_enable_secure if we need to be secure (e.g. setuid), |
d66e34cd | 36 | and for setting _dl_argc and _dl_argv, and then calling _dl_main. */ |
266180eb RM |
37 | extern ElfW(Addr) _dl_sysdep_start (void **start_argptr, |
38 | void (*dl_main) (const ElfW(Phdr) *phdr, | |
39 | ElfW(Half) phent, | |
40 | ElfW(Addr) *user_entry)); | |
4cb20290 | 41 | extern void _dl_sysdep_start_cleanup (void); |
d66e34cd | 42 | |
14bab8de UD |
43 | /* System-dependent function to read a file's whole contents |
44 | in the most convenient manner available. */ | |
45 | extern void *_dl_sysdep_read_whole_file (const char *filename, | |
46 | size_t *filesize_ptr, | |
47 | int mmap_prot); | |
48 | ||
fd26970f | 49 | /* Helper function to handle errors while resolving symbols. */ |
c84142e8 UD |
50 | static void print_unresolved (int errcode, const char *objname, |
51 | const char *errsting); | |
52 | ||
53 | /* Helper function to handle errors when a version is missing. */ | |
54 | static void print_missing_version (int errcode, const char *objname, | |
55 | const char *errsting); | |
fd26970f | 56 | |
ea278354 UD |
57 | |
58 | /* This is a list of all the modes the dynamic loader can be in. */ | |
59 | enum mode { normal, list, verify, trace }; | |
60 | ||
61 | /* Process all environments variables the dynamic linker must recognize. | |
62 | Since all of them start with `LD_' we are a bit smarter while finding | |
63 | all the entries. */ | |
64 | static void process_envvars (enum mode *modep, int *lazyp); | |
65 | ||
d66e34cd RM |
66 | int _dl_argc; |
67 | char **_dl_argv; | |
4cb20290 | 68 | const char *_dl_rpath; |
cf29ffbe | 69 | int _dl_verbose; |
0a54e401 UD |
70 | const char *_dl_platform; |
71 | size_t _dl_platformlen; | |
f41c8091 | 72 | unsigned long _dl_hwcap; |
0a54e401 | 73 | struct r_search_path *_dl_search_paths; |
3996f34b UD |
74 | const char *_dl_profile; |
75 | const char *_dl_profile_output; | |
76 | struct link_map *_dl_profile_map; | |
b5efde2f | 77 | int _dl_debug_libs; |
7dea968e | 78 | int _dl_debug_impcalls; |
0c367d92 | 79 | int _dl_debug_bindings; |
de100ca7 | 80 | int _dl_debug_symbols; |
8193034b UD |
81 | int _dl_debug_versions; |
82 | int _dl_debug_reloc; | |
83 | int _dl_debug_files; | |
d66e34cd | 84 | |
39778c6c UD |
85 | /* Set nonzero during loading and initialization of executable and |
86 | libraries, cleared before the executable's entry point runs. This | |
87 | must not be initialized to nonzero, because the unused dynamic | |
88 | linker loaded in for libc.so's "ld.so.1" dep will provide the | |
89 | definition seen by libc.so's initializer; that value must be zero, | |
90 | and will be since that dynamic linker's _dl_start and dl_main will | |
91 | never be called. */ | |
92 | int _dl_starting_up; | |
93 | ||
266180eb RM |
94 | static void dl_main (const ElfW(Phdr) *phdr, |
95 | ElfW(Half) phent, | |
96 | ElfW(Addr) *user_entry); | |
d66e34cd | 97 | |
ee188d55 | 98 | struct link_map _dl_rtld_map; |
c84142e8 | 99 | struct libname_list _dl_rtld_libname; |
f41c8091 | 100 | struct libname_list _dl_rtld_libname2; |
86d2c878 | 101 | |
b1dbbaa4 RM |
102 | #ifdef RTLD_START |
103 | RTLD_START | |
104 | #else | |
105 | #error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START" | |
106 | #endif | |
107 | ||
ceb2d9aa | 108 | static ElfW(Addr) |
d66e34cd RM |
109 | _dl_start (void *arg) |
110 | { | |
86d2c878 | 111 | struct link_map bootstrap_map; |
d66e34cd | 112 | |
b1dbbaa4 RM |
113 | /* This #define produces dynamic linking inline functions for |
114 | bootstrap relocation instead of general-purpose relocation. */ | |
115 | #define RTLD_BOOTSTRAP | |
c84142e8 | 116 | #define RESOLVE(sym, version, flags) bootstrap_map.l_addr |
b1dbbaa4 RM |
117 | #include "dynamic-link.h" |
118 | ||
d66e34cd | 119 | /* Figure out the run-time load address of the dynamic linker itself. */ |
86d2c878 | 120 | bootstrap_map.l_addr = elf_machine_load_address (); |
d66e34cd | 121 | |
47707456 UD |
122 | /* Read our own dynamic section and fill in the info array. */ |
123 | bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic (); | |
86d2c878 | 124 | elf_get_dynamic_info (bootstrap_map.l_ld, bootstrap_map.l_info); |
d66e34cd RM |
125 | |
126 | #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC | |
86d2c878 | 127 | ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info); |
d66e34cd RM |
128 | #endif |
129 | ||
130 | /* Relocate ourselves so we can do normal function calls and | |
131 | data access using the global offset table. */ | |
421f82e5 | 132 | |
3996f34b | 133 | ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0); |
ea7eb7e3 UD |
134 | /* Please note that we don't allow profiling of this object and |
135 | therefore need not test whether we have to allocate the array | |
136 | for the relocation results (as done in dl-reloc.c). */ | |
421f82e5 | 137 | |
d66e34cd RM |
138 | /* Now life is sane; we can call functions and access global data. |
139 | Set up to use the operating system facilities, and find out from | |
140 | the operating system's program loader where to find the program | |
141 | header table in core. */ | |
142 | ||
86d2c878 | 143 | /* Transfer data about ourselves to the permanent link_map structure. */ |
ee188d55 RM |
144 | _dl_rtld_map.l_addr = bootstrap_map.l_addr; |
145 | _dl_rtld_map.l_ld = bootstrap_map.l_ld; | |
f41c8091 | 146 | _dl_rtld_map.l_opencount = 1; |
ee188d55 RM |
147 | memcpy (_dl_rtld_map.l_info, bootstrap_map.l_info, |
148 | sizeof _dl_rtld_map.l_info); | |
149 | _dl_setup_hash (&_dl_rtld_map); | |
86d2c878 | 150 | |
4cb20290 RM |
151 | /* Cache the DT_RPATH stored in ld.so itself; this will be |
152 | the default search path. */ | |
f41c8091 UD |
153 | if (_dl_rtld_map.l_info[DT_STRTAB] && _dl_rtld_map.l_info[DT_RPATH]) |
154 | { | |
155 | _dl_rpath = (void *) (_dl_rtld_map.l_addr + | |
156 | _dl_rtld_map.l_info[DT_STRTAB]->d_un.d_ptr + | |
157 | _dl_rtld_map.l_info[DT_RPATH]->d_un.d_val); | |
158 | } | |
d66e34cd RM |
159 | |
160 | /* Call the OS-dependent function to set up life so we can do things like | |
161 | file access. It will call `dl_main' (below) to do all the real work | |
162 | of the dynamic linker, and then unwind our frame and run the user | |
163 | entry point on the same stack we entered on. */ | |
8d6468d0 | 164 | return _dl_sysdep_start (arg, &dl_main); |
d66e34cd RM |
165 | } |
166 | ||
d66e34cd RM |
167 | /* Now life is peachy; we can do all normal operations. |
168 | On to the real work. */ | |
169 | ||
f21acc89 | 170 | void ENTRY_POINT (void); |
d66e34cd | 171 | |
993b3242 UD |
172 | /* Some helper functions. */ |
173 | ||
174 | /* Arguments to relocate_doit. */ | |
175 | struct relocate_args | |
176 | { | |
177 | struct link_map *l; | |
178 | int lazy; | |
179 | }; | |
180 | ||
181 | struct map_args | |
182 | { | |
183 | /* Argument to map_doit. */ | |
184 | char *str; | |
185 | /* Return value of map_doit. */ | |
186 | struct link_map *main_map; | |
187 | }; | |
188 | ||
189 | /* Arguments to version_check_doit. */ | |
190 | struct version_check_args | |
191 | { | |
192 | struct link_map *main_map; | |
193 | int doexit; | |
194 | }; | |
195 | ||
196 | static void | |
197 | relocate_doit (void *a) | |
198 | { | |
199 | struct relocate_args *args = (struct relocate_args *) a; | |
200 | ||
201 | _dl_relocate_object (args->l, _dl_object_relocation_scope (args->l), | |
202 | args->lazy); | |
203 | } | |
204 | ||
205 | static void | |
206 | map_doit (void *a) | |
207 | { | |
208 | struct map_args *args = (struct map_args *)a; | |
c6222ab9 | 209 | args->main_map = _dl_map_object (NULL, args->str, 0, lt_library, 0); |
993b3242 UD |
210 | } |
211 | ||
212 | static void | |
213 | version_check_doit (void *a) | |
214 | { | |
215 | struct version_check_args *args = (struct version_check_args *)a; | |
216 | if (_dl_check_all_versions (args->main_map, 1) && args->doexit) | |
217 | /* We cannot start the application. Abort now. */ | |
218 | _exit (1); | |
219 | } | |
220 | ||
ce37fa88 UD |
221 | |
222 | static inline struct link_map * | |
223 | find_needed (const char *name) | |
224 | { | |
225 | unsigned int n; | |
226 | ||
227 | for (n = 0; n < _dl_loaded->l_nsearchlist; ++n) | |
228 | if (_dl_name_match_p (name, _dl_loaded->l_searchlist[n])) | |
229 | return _dl_loaded->l_searchlist[n]; | |
230 | ||
231 | /* Should never happen. */ | |
232 | return NULL; | |
233 | } | |
234 | ||
235 | static int | |
236 | match_version (const char *string, struct link_map *map) | |
237 | { | |
238 | const char *strtab = (const char *) (map->l_addr | |
239 | + map->l_info[DT_STRTAB]->d_un.d_ptr); | |
240 | ElfW(Verdef) *def; | |
241 | ||
242 | #define VERDEFTAG (DT_NUM + DT_PROCNUM + DT_VERSIONTAGIDX (DT_VERDEF)) | |
243 | if (map->l_info[VERDEFTAG] == NULL) | |
244 | /* The file has no symbol versioning. */ | |
245 | return 0; | |
246 | ||
247 | def = (ElfW(Verdef) *) ((char *) map->l_addr | |
248 | + map->l_info[VERDEFTAG]->d_un.d_ptr); | |
249 | while (1) | |
250 | { | |
251 | ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux); | |
252 | ||
253 | /* Compare the version strings. */ | |
254 | if (strcmp (string, strtab + aux->vda_name) == 0) | |
255 | /* Bingo! */ | |
256 | return 1; | |
257 | ||
258 | /* If no more definitions we failed to find what we want. */ | |
259 | if (def->vd_next == 0) | |
260 | break; | |
261 | ||
262 | /* Next definition. */ | |
263 | def = (ElfW(Verdef) *) ((char *) def + def->vd_next); | |
264 | } | |
265 | ||
266 | return 0; | |
267 | } | |
268 | ||
120b4c49 UD |
269 | static unsigned int _dl_skip_args; /* Nonzero if we were run directly. */ |
270 | static const char *library_path; /* The library search path. */ | |
271 | static const char *preloadlist; /* The list preloaded objects. */ | |
272 | static int version_info; /* Nonzero if information about | |
273 | versions has to be printed. */ | |
a1a9d215 | 274 | |
d66e34cd | 275 | static void |
266180eb RM |
276 | dl_main (const ElfW(Phdr) *phdr, |
277 | ElfW(Half) phent, | |
278 | ElfW(Addr) *user_entry) | |
d66e34cd | 279 | { |
266180eb | 280 | const ElfW(Phdr) *ph; |
ceb2d9aa | 281 | struct link_map *main_map; |
0200214b | 282 | int lazy; |
ea278354 | 283 | enum mode mode; |
2064087b RM |
284 | struct link_map **preloads; |
285 | unsigned int npreloads; | |
14bab8de UD |
286 | size_t file_size; |
287 | char *file; | |
2f6d1f1b | 288 | int has_interp = 0; |
77aba05b | 289 | unsigned int i; |
d66e34cd | 290 | |
ea278354 UD |
291 | /* Process the environment variable which control the behaviour. */ |
292 | process_envvars (&mode, &lazy); | |
3996f34b | 293 | |
46ec036d UD |
294 | /* Set up a flag which tells we are just starting. */ |
295 | _dl_starting_up = 1; | |
296 | ||
f21acc89 | 297 | if (*user_entry == (ElfW(Addr)) &ENTRY_POINT) |
0200214b RM |
298 | { |
299 | /* Ho ho. We are not the program interpreter! We are the program | |
300 | itself! This means someone ran ld.so as a command. Well, that | |
301 | might be convenient to do sometimes. We support it by | |
302 | interpreting the args like this: | |
303 | ||
304 | ld.so PROGRAM ARGS... | |
305 | ||
306 | The first argument is the name of a file containing an ELF | |
307 | executable we will load and run with the following arguments. | |
308 | To simplify life here, PROGRAM is searched for using the | |
309 | normal rules for shared objects, rather than $PATH or anything | |
310 | like that. We just load it and use its entry point; we don't | |
311 | pay attention to its PT_INTERP command (we are the interpreter | |
312 | ourselves). This is an easy way to test a new ld.so before | |
313 | installing it. */ | |
421f82e5 | 314 | |
ffee1316 RM |
315 | /* Note the place where the dynamic linker actually came from. */ |
316 | _dl_rtld_map.l_name = _dl_argv[0]; | |
6a76c115 | 317 | |
fd26970f UD |
318 | while (_dl_argc > 1) |
319 | if (! strcmp (_dl_argv[1], "--list")) | |
320 | { | |
321 | mode = list; | |
322 | lazy = -1; /* This means do no dependency analysis. */ | |
61965e9b | 323 | |
fd26970f UD |
324 | ++_dl_skip_args; |
325 | --_dl_argc; | |
326 | ++_dl_argv; | |
327 | } | |
328 | else if (! strcmp (_dl_argv[1], "--verify")) | |
329 | { | |
330 | mode = verify; | |
6a76c115 | 331 | |
fd26970f UD |
332 | ++_dl_skip_args; |
333 | --_dl_argc; | |
334 | ++_dl_argv; | |
335 | } | |
880f421f UD |
336 | else if (! strcmp (_dl_argv[1], "--library-path") |
337 | && _dl_argc > 2) | |
338 | { | |
339 | library_path = _dl_argv[2]; | |
340 | ||
341 | _dl_skip_args += 2; | |
342 | _dl_argc -= 2; | |
343 | _dl_argv += 2; | |
344 | } | |
fd26970f UD |
345 | else |
346 | break; | |
d66e34cd | 347 | |
61eb22d3 UD |
348 | /* If we have no further argument the program was called incorrectly. |
349 | Grant the user some education. */ | |
350 | if (_dl_argc < 2) | |
351 | _dl_sysdep_fatal ("\ | |
352 | Usage: ld.so [--list|--verify] EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\ | |
353 | You have invoked `ld.so', the helper program for shared library executables.\n\ | |
354 | This program usually lives in the file `/lib/ld.so', and special directives\n\ | |
355 | in executable files using ELF shared libraries tell the system's program\n\ | |
356 | loader to load the helper program from this file. This helper program loads\n\ | |
357 | the shared libraries needed by the program executable, prepares the program\n\ | |
358 | to run, and runs it. You may invoke this helper program directly from the\n\ | |
359 | command line to load and run an ELF executable file; this is like executing\n\ | |
360 | that file itself, but always uses this helper program from the file you\n\ | |
361 | specified, instead of the helper program file specified in the executable\n\ | |
362 | file you run. This is mostly of use for maintainers to test new versions\n\ | |
363 | of this helper program; chances are you did not intend to run this program.\n", | |
364 | NULL); | |
365 | ||
0200214b RM |
366 | ++_dl_skip_args; |
367 | --_dl_argc; | |
368 | ++_dl_argv; | |
91f62ce6 | 369 | |
da832465 UD |
370 | /* Initialize the data structures for the search paths for shared |
371 | objects. */ | |
372 | _dl_init_paths (library_path); | |
373 | ||
2de99474 UD |
374 | if (mode == verify) |
375 | { | |
dcf0671d | 376 | char *err_str = NULL; |
2de99474 | 377 | const char *obj_name __attribute__ ((unused)); |
993b3242 | 378 | struct map_args args; |
2de99474 | 379 | |
993b3242 UD |
380 | args.str = _dl_argv[0]; |
381 | (void) _dl_catch_error (&err_str, &obj_name, map_doit, &args); | |
382 | main_map = args.main_map; | |
2de99474 | 383 | if (err_str != NULL) |
dcf0671d UD |
384 | { |
385 | free (err_str); | |
386 | _exit (EXIT_FAILURE); | |
387 | } | |
2de99474 UD |
388 | } |
389 | else | |
c6222ab9 | 390 | main_map = _dl_map_object (NULL, _dl_argv[0], 0, lt_library, 0); |
2de99474 | 391 | |
ceb2d9aa UD |
392 | phdr = main_map->l_phdr; |
393 | phent = main_map->l_phnum; | |
394 | main_map->l_name = (char *) ""; | |
395 | *user_entry = main_map->l_entry; | |
0200214b RM |
396 | } |
397 | else | |
398 | { | |
399 | /* Create a link_map for the executable itself. | |
400 | This will be what dlopen on "" returns. */ | |
1618c590 | 401 | main_map = _dl_new_object ((char *) "", "", lt_executable); |
ceb2d9aa | 402 | if (main_map == NULL) |
762a2918 | 403 | _dl_sysdep_fatal ("cannot allocate memory for link map\n", NULL); |
ceb2d9aa UD |
404 | main_map->l_phdr = phdr; |
405 | main_map->l_phnum = phent; | |
406 | main_map->l_entry = *user_entry; | |
3e5f5557 | 407 | main_map->l_opencount = 1; |
da832465 | 408 | |
97a51d8a UD |
409 | /* We delay initializing the path structure until we got the dynamic |
410 | information for the program. */ | |
0200214b RM |
411 | } |
412 | ||
413 | /* Scan the program header table for the dynamic section. */ | |
414 | for (ph = phdr; ph < &phdr[phent]; ++ph) | |
415 | switch (ph->p_type) | |
416 | { | |
da832465 UD |
417 | case PT_PHDR: |
418 | /* Find out the load address. */ | |
419 | main_map->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr; | |
420 | break; | |
0200214b RM |
421 | case PT_DYNAMIC: |
422 | /* This tells us where to find the dynamic section, | |
423 | which tells us everything we need to do. */ | |
ceb2d9aa | 424 | main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr; |
0200214b RM |
425 | break; |
426 | case PT_INTERP: | |
427 | /* This "interpreter segment" was used by the program loader to | |
428 | find the program interpreter, which is this program itself, the | |
429 | dynamic linker. We note what name finds us, so that a future | |
430 | dlopen call or DT_NEEDED entry, for something that wants to link | |
431 | against the dynamic linker as a shared library, will know that | |
432 | the shared object is already loaded. */ | |
ceb2d9aa | 433 | _dl_rtld_libname.name = (const char *) main_map->l_addr + ph->p_vaddr; |
c84142e8 UD |
434 | _dl_rtld_libname.next = NULL; |
435 | _dl_rtld_map.l_libname = &_dl_rtld_libname; | |
f41c8091 UD |
436 | |
437 | /* Ordinarilly, we would get additional names for the loader from | |
438 | our DT_SONAME. This can't happen if we were actually linked as | |
439 | a static executable (detect this case when we have no DYNAMIC). | |
440 | If so, assume the filename component of the interpreter path to | |
441 | be our SONAME, and add it to our name list. */ | |
442 | if (_dl_rtld_map.l_ld == NULL) | |
443 | { | |
444 | char *p = strrchr (_dl_rtld_libname.name, '/'); | |
445 | if (p) | |
446 | { | |
447 | _dl_rtld_libname2.name = p+1; | |
448 | _dl_rtld_libname2.next = NULL; | |
449 | _dl_rtld_libname.next = &_dl_rtld_libname2; | |
450 | } | |
451 | } | |
452 | ||
2f6d1f1b | 453 | has_interp = 1; |
0200214b RM |
454 | break; |
455 | } | |
ffee1316 | 456 | if (! _dl_rtld_map.l_libname && _dl_rtld_map.l_name) |
c84142e8 UD |
457 | { |
458 | /* We were invoked directly, so the program might not have a | |
459 | PT_INTERP. */ | |
460 | _dl_rtld_libname.name = _dl_rtld_map.l_name; | |
461 | _dl_rtld_libname.next = NULL; | |
462 | _dl_rtld_map.l_libname = &_dl_rtld_libname; | |
463 | } | |
ffee1316 RM |
464 | else |
465 | assert (_dl_rtld_map.l_libname); /* How else did we get here? */ | |
0200214b | 466 | |
61965e9b RM |
467 | if (mode == verify) |
468 | /* We were called just to verify that this is a dynamic executable | |
469 | using us as the program interpreter. */ | |
ceb2d9aa | 470 | _exit (main_map->l_ld == NULL ? 1 : has_interp ? 0 : 2); |
61965e9b | 471 | |
0200214b | 472 | /* Extract the contents of the dynamic section for easy access. */ |
ceb2d9aa UD |
473 | elf_get_dynamic_info (main_map->l_ld, main_map->l_info); |
474 | if (main_map->l_info[DT_HASH]) | |
0200214b | 475 | /* Set up our cache of pointers into the hash table. */ |
ceb2d9aa | 476 | _dl_setup_hash (main_map); |
0200214b | 477 | |
97a51d8a UD |
478 | if (*user_entry != (ElfW(Addr)) &ENTRY_POINT) |
479 | /* Initialize the data structures for the search paths for shared | |
480 | objects. */ | |
120b4c49 | 481 | _dl_init_paths (library_path); |
97a51d8a | 482 | |
0200214b | 483 | /* Put the link_map for ourselves on the chain so it can be found by |
ceb2d9aa UD |
484 | name. Note that at this point the global chain of link maps contains |
485 | exactly one element, which is pointed to by main_map. */ | |
ffee1316 RM |
486 | if (! _dl_rtld_map.l_name) |
487 | /* If not invoked directly, the dynamic linker shared object file was | |
488 | found by the PT_INTERP name. */ | |
c84142e8 | 489 | _dl_rtld_map.l_name = (char *) _dl_rtld_map.l_libname->name; |
ba79d61b | 490 | _dl_rtld_map.l_type = lt_library; |
ceb2d9aa UD |
491 | main_map->l_next = &_dl_rtld_map; |
492 | _dl_rtld_map.l_prev = main_map; | |
0200214b | 493 | |
14bab8de UD |
494 | /* We have two ways to specify objects to preload: via environment |
495 | variable and via the file /etc/ld.so.preload. The later can also | |
496 | be used when security is enabled. */ | |
2064087b RM |
497 | preloads = NULL; |
498 | npreloads = 0; | |
14bab8de | 499 | |
fd26970f | 500 | if (preloadlist) |
c4029823 | 501 | { |
566efee2 UD |
502 | /* The LD_PRELOAD environment variable gives list of libraries |
503 | separated by white space or colons that are loaded before the | |
fd26970f UD |
504 | executable's dependencies and prepended to the global scope |
505 | list. If the binary is running setuid all elements | |
506 | containing a '/' are ignored since it is insecure. */ | |
507 | char *list = strdupa (preloadlist); | |
508 | char *p; | |
566efee2 | 509 | while ((p = strsep (&list, " :")) != NULL) |
fd26970f UD |
510 | if (! __libc_enable_secure || strchr (p, '/') == NULL) |
511 | { | |
c6222ab9 UD |
512 | struct link_map *new_map = _dl_map_object (NULL, p, 1, |
513 | lt_library, 0); | |
bd355af0 UD |
514 | if (new_map->l_opencount == 1) |
515 | /* It is no duplicate. */ | |
516 | ++npreloads; | |
fd26970f | 517 | } |
c4029823 UD |
518 | } |
519 | ||
14bab8de UD |
520 | /* Read the contents of the file. */ |
521 | file = _dl_sysdep_read_whole_file ("/etc/ld.so.preload", &file_size, | |
522 | PROT_READ | PROT_WRITE); | |
523 | if (file) | |
524 | { | |
525 | /* Parse the file. It contains names of libraries to be loaded, | |
526 | separated by white spaces or `:'. It may also contain | |
527 | comments introduced by `#'. */ | |
528 | char *problem; | |
529 | char *runp; | |
530 | size_t rest; | |
531 | ||
532 | /* Eliminate comments. */ | |
533 | runp = file; | |
534 | rest = file_size; | |
535 | while (rest > 0) | |
536 | { | |
537 | char *comment = memchr (runp, '#', rest); | |
538 | if (comment == NULL) | |
539 | break; | |
540 | ||
541 | rest -= comment - runp; | |
542 | do | |
543 | *comment = ' '; | |
544 | while (--rest > 0 && *++comment != '\n'); | |
545 | } | |
546 | ||
547 | /* We have one problematic case: if we have a name at the end of | |
548 | the file without a trailing terminating characters, we cannot | |
549 | place the \0. Handle the case separately. */ | |
49891c10 UD |
550 | if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t' |
551 | && file[file_size - 1] != '\n' && file[file_size - 1] != ':') | |
14bab8de UD |
552 | { |
553 | problem = &file[file_size]; | |
554 | while (problem > file && problem[-1] != ' ' && problem[-1] != '\t' | |
49891c10 | 555 | && problem[-1] != '\n' && problem[-1] != ':') |
14bab8de UD |
556 | --problem; |
557 | ||
558 | if (problem > file) | |
559 | problem[-1] = '\0'; | |
560 | } | |
561 | else | |
49891c10 UD |
562 | { |
563 | problem = NULL; | |
564 | file[file_size - 1] = '\0'; | |
565 | } | |
14bab8de UD |
566 | |
567 | if (file != problem) | |
568 | { | |
569 | char *p; | |
49891c10 | 570 | runp = file + strspn (file, ": \t\n"); |
14bab8de UD |
571 | while ((p = strsep (&runp, ": \t\n")) != NULL) |
572 | { | |
c6222ab9 | 573 | struct link_map *new_map = _dl_map_object (NULL, p, 1, |
bd355af0 UD |
574 | lt_library, 0); |
575 | if (new_map->l_opencount == 1) | |
576 | /* It is no duplicate. */ | |
577 | ++npreloads; | |
49891c10 UD |
578 | |
579 | if (runp != NULL) | |
580 | runp += strspn (runp, ": \t\n"); | |
14bab8de UD |
581 | } |
582 | } | |
583 | ||
584 | if (problem != NULL) | |
585 | { | |
586 | char *p = strndupa (problem, file_size - (problem - file)); | |
c6222ab9 UD |
587 | struct link_map *new_map = _dl_map_object (NULL, p, 1, |
588 | lt_library, 0); | |
bd355af0 UD |
589 | if (new_map->l_opencount == 1) |
590 | /* It is no duplicate. */ | |
591 | ++npreloads; | |
14bab8de UD |
592 | } |
593 | ||
594 | /* We don't need the file anymore. */ | |
595 | __munmap (file, file_size); | |
596 | } | |
597 | ||
14bab8de UD |
598 | if (npreloads != 0) |
599 | { | |
600 | /* Set up PRELOADS with a vector of the preloaded libraries. */ | |
601 | struct link_map *l; | |
14bab8de UD |
602 | preloads = __alloca (npreloads * sizeof preloads[0]); |
603 | l = _dl_rtld_map.l_next; /* End of the chain before preloads. */ | |
604 | i = 0; | |
605 | do | |
606 | { | |
607 | preloads[i++] = l; | |
608 | l = l->l_next; | |
609 | } while (l); | |
610 | assert (i == npreloads); | |
611 | } | |
612 | ||
2064087b RM |
613 | /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD |
614 | specified some libraries to load, these are inserted before the actual | |
615 | dependencies in the executable's searchlist for symbol resolution. */ | |
ceb2d9aa | 616 | _dl_map_object_deps (main_map, preloads, npreloads, mode == trace); |
d66e34cd | 617 | |
2064087b | 618 | #ifndef MAP_ANON |
f332db02 RM |
619 | /* We are done mapping things, so close the zero-fill descriptor. */ |
620 | __close (_dl_zerofd); | |
621 | _dl_zerofd = -1; | |
2064087b | 622 | #endif |
f332db02 | 623 | |
f9496a7b RM |
624 | /* Remove _dl_rtld_map from the chain. */ |
625 | _dl_rtld_map.l_prev->l_next = _dl_rtld_map.l_next; | |
626 | if (_dl_rtld_map.l_next) | |
627 | _dl_rtld_map.l_next->l_prev = _dl_rtld_map.l_prev; | |
628 | ||
629 | if (_dl_rtld_map.l_opencount) | |
0200214b | 630 | { |
f9496a7b RM |
631 | /* Some DT_NEEDED entry referred to the interpreter object itself, so |
632 | put it back in the list of visible objects. We insert it into the | |
633 | chain in symbol search order because gdb uses the chain's order as | |
634 | its symbol search order. */ | |
77aba05b | 635 | i = 1; |
ceb2d9aa | 636 | while (main_map->l_searchlist[i] != &_dl_rtld_map) |
f9496a7b | 637 | ++i; |
ceb2d9aa UD |
638 | _dl_rtld_map.l_prev = main_map->l_searchlist[i - 1]; |
639 | _dl_rtld_map.l_next = (i + 1 < main_map->l_nsearchlist ? | |
640 | main_map->l_searchlist[i + 1] : NULL); | |
f9496a7b RM |
641 | assert (_dl_rtld_map.l_prev->l_next == _dl_rtld_map.l_next); |
642 | _dl_rtld_map.l_prev->l_next = &_dl_rtld_map; | |
4d02a5b1 | 643 | if (_dl_rtld_map.l_next) |
f9496a7b RM |
644 | { |
645 | assert (_dl_rtld_map.l_next->l_prev == _dl_rtld_map.l_prev); | |
646 | _dl_rtld_map.l_next->l_prev = &_dl_rtld_map; | |
647 | } | |
0200214b | 648 | } |
d66e34cd | 649 | |
c84142e8 UD |
650 | /* Now let us see whether all libraries are available in the |
651 | versions we need. */ | |
652 | { | |
993b3242 UD |
653 | struct version_check_args args; |
654 | args.doexit = mode == normal; | |
655 | args.main_map = main_map; | |
656 | _dl_receive_error (print_missing_version, version_check_doit, &args); | |
c84142e8 UD |
657 | } |
658 | ||
2de99474 | 659 | if (mode != normal) |
0200214b RM |
660 | { |
661 | /* We were run just to list the shared libraries. It is | |
662 | important that we do this before real relocation, because the | |
663 | functions we call below for output may no longer work properly | |
664 | after relocation. */ | |
0200214b RM |
665 | if (! _dl_loaded->l_info[DT_NEEDED]) |
666 | _dl_sysdep_message ("\t", "statically linked\n", NULL); | |
667 | else | |
ceb2d9aa UD |
668 | { |
669 | struct link_map *l; | |
670 | ||
671 | for (l = _dl_loaded->l_next; l; l = l->l_next) | |
672 | if (l->l_opencount == 0) | |
673 | /* The library was not found. */ | |
674 | _dl_sysdep_message ("\t", l->l_libname->name, " => not found\n", | |
675 | NULL); | |
676 | else | |
677 | { | |
678 | char buf[20], *bp; | |
679 | buf[sizeof buf - 1] = '\0'; | |
af6f3906 | 680 | bp = _itoa_word (l->l_addr, &buf[sizeof buf - 1], 16, 0); |
ceb2d9aa UD |
681 | while ((size_t) (&buf[sizeof buf - 1] - bp) |
682 | < sizeof l->l_addr * 2) | |
683 | *--bp = '0'; | |
684 | _dl_sysdep_message ("\t", l->l_libname->name, " => ", | |
685 | l->l_name, " (0x", bp, ")\n", NULL); | |
686 | } | |
687 | } | |
1a3a58fd | 688 | |
2de99474 | 689 | if (mode != trace) |
cddcfecf RM |
690 | for (i = 1; i < _dl_argc; ++i) |
691 | { | |
692 | const ElfW(Sym) *ref = NULL; | |
693 | ElfW(Addr) loadbase = _dl_lookup_symbol (_dl_argv[i], &ref, | |
694 | &_dl_default_scope[2], | |
dcf0671d | 695 | "argument", |
a2b08ee5 | 696 | ELF_MACHINE_JMP_SLOT); |
cddcfecf RM |
697 | char buf[20], *bp; |
698 | buf[sizeof buf - 1] = '\0'; | |
af6f3906 | 699 | bp = _itoa_word (ref->st_value, &buf[sizeof buf - 1], 16, 0); |
14bab8de | 700 | while ((size_t) (&buf[sizeof buf - 1] - bp) < sizeof loadbase * 2) |
cddcfecf RM |
701 | *--bp = '0'; |
702 | _dl_sysdep_message (_dl_argv[i], " found at 0x", bp, NULL); | |
703 | buf[sizeof buf - 1] = '\0'; | |
af6f3906 | 704 | bp = _itoa_word (loadbase, &buf[sizeof buf - 1], 16, 0); |
14bab8de | 705 | while ((size_t) (&buf[sizeof buf - 1] - bp) < sizeof loadbase * 2) |
cddcfecf RM |
706 | *--bp = '0'; |
707 | _dl_sysdep_message (" in object at 0x", bp, "\n", NULL); | |
708 | } | |
ce37fa88 | 709 | else |
fd26970f | 710 | { |
ce37fa88 UD |
711 | if (lazy >= 0) |
712 | { | |
713 | /* We have to do symbol dependency testing. */ | |
714 | struct relocate_args args; | |
715 | struct link_map *l; | |
993b3242 | 716 | |
ce37fa88 | 717 | args.lazy = lazy; |
fd26970f | 718 | |
ce37fa88 UD |
719 | l = _dl_loaded; |
720 | while (l->l_next) | |
721 | l = l->l_next; | |
722 | do | |
723 | { | |
724 | if (l != &_dl_rtld_map && l->l_opencount > 0) | |
725 | { | |
726 | args.l = l; | |
727 | _dl_receive_error (print_unresolved, relocate_doit, | |
728 | &args); | |
729 | *_dl_global_scope_end = NULL; | |
730 | } | |
731 | l = l->l_prev; | |
732 | } while (l); | |
733 | } | |
734 | ||
735 | #define VERNEEDTAG (DT_NUM + DT_PROCNUM + DT_VERSIONTAGIDX (DT_VERNEED)) | |
120b4c49 | 736 | if (version_info) |
fd26970f | 737 | { |
ce37fa88 UD |
738 | /* Print more information. This means here, print information |
739 | about the versions needed. */ | |
740 | int first = 1; | |
741 | struct link_map *map = _dl_loaded; | |
742 | ||
743 | for (map = _dl_loaded; map != NULL; map = map->l_next) | |
fd26970f | 744 | { |
f41c8091 | 745 | const char *strtab; |
ce37fa88 | 746 | ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG]; |
f41c8091 UD |
747 | ElfW(Verneed) *ent; |
748 | ||
749 | if (dyn == NULL) | |
750 | continue; | |
751 | ||
752 | strtab = (const char *) | |
753 | (map->l_addr + map->l_info[DT_STRTAB]->d_un.d_ptr); | |
754 | ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr); | |
ce37fa88 | 755 | |
f41c8091 | 756 | if (first) |
ce37fa88 | 757 | { |
f41c8091 UD |
758 | _dl_sysdep_message ("\n\tVersion information:\n", NULL); |
759 | first = 0; | |
760 | } | |
ce37fa88 | 761 | |
f41c8091 UD |
762 | _dl_sysdep_message ("\t", (map->l_name[0] |
763 | ? map->l_name : _dl_argv[0]), | |
764 | ":\n", NULL); | |
765 | ||
766 | while (1) | |
767 | { | |
768 | ElfW(Vernaux) *aux; | |
769 | struct link_map *needed; | |
ce37fa88 | 770 | |
f41c8091 UD |
771 | needed = find_needed (strtab + ent->vn_file); |
772 | aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux); | |
ce37fa88 UD |
773 | |
774 | while (1) | |
775 | { | |
f41c8091 UD |
776 | const char *fname = NULL; |
777 | ||
778 | _dl_sysdep_message ("\t\t", | |
779 | strtab + ent->vn_file, | |
780 | " (", strtab + aux->vna_name, | |
781 | ") ", | |
782 | (aux->vna_flags | |
783 | & VER_FLG_WEAK | |
784 | ? "[WEAK] " : ""), | |
785 | "=> ", NULL); | |
786 | ||
787 | if (needed != NULL | |
788 | && match_version (strtab+aux->vna_name, needed)) | |
789 | fname = needed->l_name; | |
790 | ||
791 | _dl_sysdep_message (fname ?: "not found", "\n", | |
792 | NULL); | |
ce37fa88 | 793 | |
f41c8091 UD |
794 | if (aux->vna_next == 0) |
795 | /* No more symbols. */ | |
ce37fa88 UD |
796 | break; |
797 | ||
f41c8091 UD |
798 | /* Next symbol. */ |
799 | aux = (ElfW(Vernaux) *) ((char *) aux | |
800 | + aux->vna_next); | |
ce37fa88 | 801 | } |
f41c8091 UD |
802 | |
803 | if (ent->vn_next == 0) | |
804 | /* No more dependencies. */ | |
805 | break; | |
806 | ||
807 | /* Next dependency. */ | |
808 | ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next); | |
ce37fa88 | 809 | } |
fd26970f | 810 | } |
ce37fa88 | 811 | } |
fd26970f | 812 | } |
d66e34cd | 813 | |
0200214b RM |
814 | _exit (0); |
815 | } | |
86d2c878 | 816 | |
ba79d61b RM |
817 | { |
818 | /* Now we have all the objects loaded. Relocate them all except for | |
819 | the dynamic linker itself. We do this in reverse order so that copy | |
820 | relocs of earlier objects overwrite the data written by later | |
821 | objects. We do not re-relocate the dynamic linker itself in this | |
822 | loop because that could result in the GOT entries for functions we | |
823 | call being changed, and that would break us. It is safe to relocate | |
824 | the dynamic linker out of order because it has no copy relocs (we | |
825 | know that because it is self-contained). */ | |
826 | ||
ceb2d9aa | 827 | struct link_map *l; |
ba79d61b RM |
828 | l = _dl_loaded; |
829 | while (l->l_next) | |
830 | l = l->l_next; | |
831 | do | |
832 | { | |
833 | if (l != &_dl_rtld_map) | |
834 | { | |
835 | _dl_relocate_object (l, _dl_object_relocation_scope (l), lazy); | |
836 | *_dl_global_scope_end = NULL; | |
837 | } | |
838 | l = l->l_prev; | |
839 | } while (l); | |
840 | ||
841 | /* Do any necessary cleanups for the startup OS interface code. | |
842 | We do these now so that no calls are made after rtld re-relocation | |
843 | which might be resolved to different functions than we expect. | |
844 | We cannot do this before relocating the other objects because | |
845 | _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */ | |
846 | _dl_sysdep_start_cleanup (); | |
847 | ||
848 | if (_dl_rtld_map.l_opencount > 0) | |
849 | /* There was an explicit ref to the dynamic linker as a shared lib. | |
850 | Re-relocate ourselves with user-controlled symbol definitions. */ | |
851 | _dl_relocate_object (&_dl_rtld_map, &_dl_default_scope[2], 0); | |
852 | } | |
ac16e905 | 853 | |
4d6acc61 RM |
854 | { |
855 | /* Initialize _r_debug. */ | |
856 | struct r_debug *r = _dl_debug_initialize (_dl_rtld_map.l_addr); | |
ceb2d9aa | 857 | struct link_map *l; |
4d6acc61 RM |
858 | |
859 | l = _dl_loaded; | |
ec42724d RM |
860 | |
861 | #ifdef ELF_MACHINE_DEBUG_SETUP | |
862 | ||
863 | /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */ | |
864 | ||
865 | ELF_MACHINE_DEBUG_SETUP (l, r); | |
866 | ELF_MACHINE_DEBUG_SETUP (&_dl_rtld_map, r); | |
867 | ||
868 | #else | |
869 | ||
4d6acc61 RM |
870 | if (l->l_info[DT_DEBUG]) |
871 | /* There is a DT_DEBUG entry in the dynamic section. Fill it in | |
872 | with the run-time address of the r_debug structure */ | |
873 | l->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r; | |
874 | ||
d746b89c RM |
875 | /* Fill in the pointer in the dynamic linker's own dynamic section, in |
876 | case you run gdb on the dynamic linker directly. */ | |
877 | if (_dl_rtld_map.l_info[DT_DEBUG]) | |
878 | _dl_rtld_map.l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r; | |
879 | ||
ec42724d RM |
880 | #endif |
881 | ||
4d6acc61 RM |
882 | /* Notify the debugger that all objects are now mapped in. */ |
883 | r->r_state = RT_ADD; | |
884 | _dl_debug_state (); | |
885 | } | |
0200214b | 886 | |
3996f34b UD |
887 | /* Now enable profiling if needed. */ |
888 | if (_dl_profile_map != NULL) | |
889 | /* We must prepare the profiling. */ | |
890 | _dl_start_profile (_dl_profile_map, _dl_profile_output); | |
891 | ||
d66e34cd RM |
892 | /* Once we return, _dl_sysdep_start will invoke |
893 | the DT_INIT functions and then *USER_ENTRY. */ | |
894 | } | |
fd26970f UD |
895 | \f |
896 | /* This is a little helper function for resolving symbols while | |
897 | tracing the binary. */ | |
898 | static void | |
c84142e8 UD |
899 | print_unresolved (int errcode __attribute__ ((unused)), const char *objname, |
900 | const char *errstring) | |
fd26970f | 901 | { |
3996f34b UD |
902 | if (objname[0] == '\0') |
903 | objname = _dl_argv[0] ?: "<main program>"; | |
fd26970f UD |
904 | _dl_sysdep_error (errstring, " (", objname, ")\n", NULL); |
905 | } | |
c84142e8 UD |
906 | \f |
907 | /* This is a little helper function for resolving symbols while | |
908 | tracing the binary. */ | |
909 | static void | |
910 | print_missing_version (int errcode __attribute__ ((unused)), | |
911 | const char *objname, const char *errstring) | |
912 | { | |
913 | _dl_sysdep_error (_dl_argv[0] ?: "<program name unknown>", ": ", | |
914 | objname, ": ", errstring, "\n", NULL); | |
915 | } | |
ea278354 | 916 | \f |
7dea968e UD |
917 | /* Nonzero if any of the debugging options is enabled. */ |
918 | static int any_debug; | |
919 | ||
b5efde2f UD |
920 | /* Process the string given as the parameter which explains which debugging |
921 | options are enabled. */ | |
922 | static void | |
923 | process_dl_debug (char *dl_debug) | |
924 | { | |
925 | do | |
926 | { | |
927 | #define issep(Ch) ((Ch) == ' ' || (Ch) == ',') | |
928 | /* Skip separating white spaces and commas. */ | |
929 | while (issep (*dl_debug)) | |
930 | ++dl_debug; | |
931 | if (*dl_debug != '\0') | |
932 | { | |
8193034b UD |
933 | if (strncmp (dl_debug, "files", 5) == 0 |
934 | && (issep (dl_debug[5]) || dl_debug[5] == '\0')) | |
0c367d92 | 935 | { |
8193034b | 936 | _dl_debug_files = 1; |
0c367d92 UD |
937 | _dl_debug_impcalls = 1; |
938 | any_debug = 1; | |
8193034b | 939 | dl_debug += 5; |
0c367d92 | 940 | } |
8193034b UD |
941 | else if (strncmp (dl_debug, "bindings", 8) == 0 |
942 | && (issep (dl_debug[8]) || dl_debug[8] == '\0')) | |
b5efde2f | 943 | { |
8193034b | 944 | _dl_debug_bindings = 1; |
7dea968e UD |
945 | _dl_debug_impcalls = 1; |
946 | any_debug = 1; | |
8193034b | 947 | dl_debug += 8; |
b5efde2f UD |
948 | } |
949 | else if (strncmp (dl_debug, "help", 4) == 0 | |
950 | && (issep (dl_debug[4]) || dl_debug[4] == '\0')) | |
951 | { | |
952 | _dl_sysdep_message ("\ | |
08b511e6 | 953 | Valid options for the LD_DEBUG environment variable are:\n\ |
b5efde2f | 954 | \n\ |
0c367d92 | 955 | bindings display information about symbol binding\n\ |
8193034b | 956 | files display processing of files and libraries\n\ |
0c367d92 UD |
957 | help display this help message and exit\n\ |
958 | libs display library search paths\n\ | |
8193034b | 959 | reloc display relocation processing\n\ |
de100ca7 | 960 | symbols display symbol table processing\n\ |
8193034b | 961 | versions display version dependencies\n\ |
0c367d92 UD |
962 | \n\ |
963 | To direct the debugging output into a file instead of standard output\n\ | |
964 | a filename can be specified using the LD_DEBUG_OUTPUT environment variable.\n", | |
965 | NULL); | |
b5efde2f UD |
966 | _exit (0); |
967 | } | |
8193034b UD |
968 | else if (strncmp (dl_debug, "libs", 4) == 0 |
969 | && (issep (dl_debug[4]) || dl_debug[4] == '\0')) | |
970 | { | |
971 | _dl_debug_libs = 1; | |
972 | _dl_debug_impcalls = 1; | |
973 | any_debug = 1; | |
974 | dl_debug += 4; | |
975 | } | |
976 | else if (strncmp (dl_debug, "reloc", 4) == 0 | |
977 | && (issep (dl_debug[5]) || dl_debug[5] == '\0')) | |
978 | { | |
979 | _dl_debug_reloc = 1; | |
980 | _dl_debug_impcalls = 1; | |
981 | any_debug = 1; | |
982 | dl_debug += 5; | |
983 | } | |
de100ca7 UD |
984 | else if (strncmp (dl_debug, "symbols", 7) == 0 |
985 | && (issep (dl_debug[7]) || dl_debug[7] == '\0')) | |
986 | { | |
987 | _dl_debug_symbols = 1; | |
988 | _dl_debug_impcalls = 1; | |
989 | any_debug = 1; | |
990 | dl_debug += 7; | |
991 | } | |
8193034b UD |
992 | else if (strncmp (dl_debug, "versions", 8) == 0 |
993 | && (issep (dl_debug[8]) || dl_debug[8] == '\0')) | |
994 | { | |
995 | _dl_debug_versions = 1; | |
996 | _dl_debug_impcalls = 1; | |
997 | any_debug = 1; | |
998 | dl_debug += 8; | |
999 | } | |
b5efde2f | 1000 | else |
77aba05b UD |
1001 | { |
1002 | /* Display a warning and skip everything until next | |
1003 | separator. */ | |
1004 | char *startp = dl_debug; | |
1005 | ||
1006 | do | |
1007 | ++dl_debug; | |
1008 | while (*dl_debug != '\0' && !issep (*dl_debug)); | |
1009 | ||
1010 | startp = strndupa (startp, dl_debug - startp); | |
1011 | _dl_sysdep_error ("warning: debug option `", startp, | |
1012 | "' unknown; try LD_DEBUG=help\n", NULL); | |
1013 | ||
1014 | } | |
b5efde2f UD |
1015 | } |
1016 | } | |
1017 | while (*dl_debug != '\0'); | |
1018 | } | |
1019 | \f | |
ea278354 UD |
1020 | /* Process all environments variables the dynamic linker must recognize. |
1021 | Since all of them start with `LD_' we are a bit smarter while finding | |
1022 | all the entries. */ | |
1023 | static void | |
1024 | process_envvars (enum mode *modep, int *lazyp) | |
1025 | { | |
1026 | char **runp = NULL; | |
1027 | char *envline; | |
1028 | enum mode mode = normal; | |
1029 | int bind_now = 0; | |
7dea968e | 1030 | char *debug_output = NULL; |
ea278354 UD |
1031 | |
1032 | /* This is the default place for profiling data file. */ | |
1033 | _dl_profile_output = "/var/tmp"; | |
1034 | ||
1035 | while ((envline = _dl_next_ld_env_entry (&runp)) != NULL) | |
1036 | { | |
1037 | int result; | |
1038 | ||
1039 | /* Do we bind early? */ | |
1040 | result = strncmp (&envline[3], "BIND_NOW=", 9); | |
1041 | if (result == 0) | |
1042 | { | |
1043 | bind_now = 1; | |
1044 | continue; | |
1045 | } | |
1046 | if (result < 0) | |
1047 | continue; | |
1048 | ||
b5efde2f UD |
1049 | /* Debugging of the dynamic linker? */ |
1050 | result = strncmp (&envline[3], "DEBUG=", 6); | |
1051 | if (result == 0) | |
1052 | { | |
1053 | process_dl_debug (&envline[9]); | |
1054 | continue; | |
1055 | } | |
1056 | if (result < 0) | |
1057 | continue; | |
1058 | ||
7dea968e UD |
1059 | /* Where to place the profiling data file. */ |
1060 | result = strncmp (&envline[3], "DEBUG_OUTPUT=", 13); | |
1061 | if (result == 0) | |
1062 | { | |
1063 | debug_output = &envline[16]; | |
1064 | continue; | |
1065 | } | |
1066 | if (result < 0) | |
1067 | continue; | |
1068 | ||
120b4c49 UD |
1069 | /* The library search path. */ |
1070 | result = strncmp (&envline[3], "LIBRARY_PATH=", 13); | |
1071 | if (result == 0) | |
1072 | { | |
1073 | library_path = &envline[16]; | |
1074 | continue; | |
1075 | } | |
1076 | if (result < 0) | |
1077 | continue; | |
1078 | ||
1079 | /* List of objects to be preloaded. */ | |
1080 | result = strncmp (&envline[3], "PRELOAD=", 8); | |
1081 | if (result == 0) | |
1082 | { | |
1083 | preloadlist = &envline[11]; | |
1084 | continue; | |
1085 | } | |
1086 | if (result < 0) | |
1087 | continue; | |
1088 | ||
ea278354 UD |
1089 | /* Which shared object shall be profiled. */ |
1090 | result = strncmp (&envline[3], "PROFILE=", 8); | |
1091 | if (result == 0) | |
1092 | { | |
1093 | _dl_profile = &envline[11]; | |
1094 | if (*_dl_profile == '\0') | |
1095 | _dl_profile = NULL; | |
1096 | continue; | |
1097 | } | |
1098 | if (result < 0) | |
1099 | continue; | |
1100 | ||
1101 | /* Where to place the profiling data file. */ | |
1102 | result = strncmp (&envline[3], "PROFILE_OUTPUT=", 15); | |
1103 | if (result == 0) | |
1104 | { | |
1105 | _dl_profile_output = &envline[18]; | |
1106 | if (*_dl_profile_output == '\0') | |
1107 | _dl_profile_output = "/var/tmp"; | |
1108 | continue; | |
1109 | } | |
1110 | if (result < 0) | |
1111 | continue; | |
1112 | ||
1113 | /* Test whether we want to see the content of the auxiliary | |
1114 | array passed up from the kernel. */ | |
1115 | result = strncmp (&envline[3], "SHOW_AUXV=", 10); | |
1116 | if (result == 0) | |
1117 | { | |
1118 | _dl_show_auxv (); | |
1119 | continue; | |
1120 | } | |
1121 | if (result < 0) | |
1122 | continue; | |
1123 | ||
1124 | /* The mode of the dynamic linker can be set. */ | |
1125 | result = strncmp (&envline[3], "TRACE_LOADED_OBJECTS=", 21); | |
1126 | if (result == 0) | |
1127 | { | |
1128 | mode = trace; | |
1129 | continue; | |
1130 | } | |
1131 | if (result < 0) | |
1132 | continue; | |
1133 | ||
120b4c49 UD |
1134 | /* Print information about versions. */ |
1135 | result = strncmp (&envline[3], "VERBOSE=", 8); | |
1136 | if (result == 0) | |
1137 | { | |
1138 | version_info = envline[11] != '\0'; | |
1139 | continue; | |
1140 | } | |
1141 | if (result < 0) | |
1142 | continue; | |
1143 | ||
ea278354 UD |
1144 | /* Warning level, verbose or not. */ |
1145 | result = strncmp (&envline[3], "WARN=", 5); | |
1146 | if (result == 0) | |
1147 | { | |
1148 | _dl_verbose = envline[8] != '\0'; | |
1149 | continue; | |
1150 | } | |
1151 | } | |
1152 | ||
7dea968e UD |
1153 | /* If we have to run the dynamic linker in debugging mode and the |
1154 | LD_DEBUG_OUTPUT environment variable is given, we write the debug | |
1155 | messages to this file. */ | |
1156 | if (any_debug && debug_output != NULL) | |
1157 | { | |
1158 | _dl_debug_fd = __open (debug_output, O_WRONLY | O_APPEND | O_CREAT, | |
1159 | 0666); | |
1160 | if (_dl_debug_fd == -1) | |
1161 | /* We use standard output if opening the file failed. */ | |
1162 | _dl_debug_fd = STDOUT_FILENO; | |
1163 | } | |
1164 | ||
ea278354 UD |
1165 | /* LAZY is determined by the environment variable LD_WARN and |
1166 | LD_BIND_NOW if we trace the binary. */ | |
1167 | if (mode == trace) | |
1168 | *lazyp = _dl_verbose ? !bind_now : -1; | |
1169 | else | |
1170 | *lazyp = !__libc_enable_secure && !bind_now; | |
1171 | ||
1172 | *modep = mode; | |
1173 | } |