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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 RM |
19 | |
20 | #include <link.h> | |
d66e34cd RM |
21 | #include <stddef.h> |
22 | #include <stdlib.h> | |
f51d1dfd | 23 | #include <string.h> |
d66e34cd | 24 | #include <unistd.h> |
2064087b | 25 | #include <sys/mman.h> /* Check if MAP_ANON is defined. */ |
ce37fa88 | 26 | #include <stdio-common/_itoa.h> |
b1dbbaa4 | 27 | #include <assert.h> |
f21acc89 | 28 | #include <entry.h> |
f5348425 RM |
29 | #include "dynamic-link.h" |
30 | ||
31 | ||
d66e34cd RM |
32 | /* System-specific function to do initial startup for the dynamic linker. |
33 | After this, file access calls and getenv must work. This is responsible | |
cddcfecf | 34 | for setting __libc_enable_secure if we need to be secure (e.g. setuid), |
d66e34cd | 35 | and for setting _dl_argc and _dl_argv, and then calling _dl_main. */ |
266180eb RM |
36 | extern ElfW(Addr) _dl_sysdep_start (void **start_argptr, |
37 | void (*dl_main) (const ElfW(Phdr) *phdr, | |
38 | ElfW(Half) phent, | |
39 | ElfW(Addr) *user_entry)); | |
4cb20290 | 40 | extern void _dl_sysdep_start_cleanup (void); |
d66e34cd | 41 | |
14bab8de UD |
42 | /* System-dependent function to read a file's whole contents |
43 | in the most convenient manner available. */ | |
44 | extern void *_dl_sysdep_read_whole_file (const char *filename, | |
45 | size_t *filesize_ptr, | |
46 | int mmap_prot); | |
47 | ||
fd26970f | 48 | /* Helper function to handle errors while resolving symbols. */ |
c84142e8 UD |
49 | static void print_unresolved (int errcode, const char *objname, |
50 | const char *errsting); | |
51 | ||
52 | /* Helper function to handle errors when a version is missing. */ | |
53 | static void print_missing_version (int errcode, const char *objname, | |
54 | const char *errsting); | |
fd26970f | 55 | |
ea278354 UD |
56 | |
57 | /* This is a list of all the modes the dynamic loader can be in. */ | |
58 | enum mode { normal, list, verify, trace }; | |
59 | ||
60 | /* Process all environments variables the dynamic linker must recognize. | |
61 | Since all of them start with `LD_' we are a bit smarter while finding | |
62 | all the entries. */ | |
63 | static void process_envvars (enum mode *modep, int *lazyp); | |
64 | ||
d66e34cd RM |
65 | int _dl_argc; |
66 | char **_dl_argv; | |
4cb20290 | 67 | const char *_dl_rpath; |
cf29ffbe | 68 | int _dl_verbose; |
0a54e401 UD |
69 | const char *_dl_platform; |
70 | size_t _dl_platformlen; | |
f41c8091 | 71 | unsigned long _dl_hwcap; |
0a54e401 | 72 | struct r_search_path *_dl_search_paths; |
3996f34b UD |
73 | const char *_dl_profile; |
74 | const char *_dl_profile_output; | |
75 | struct link_map *_dl_profile_map; | |
b5efde2f | 76 | int _dl_debug_libs; |
d66e34cd | 77 | |
39778c6c UD |
78 | /* Set nonzero during loading and initialization of executable and |
79 | libraries, cleared before the executable's entry point runs. This | |
80 | must not be initialized to nonzero, because the unused dynamic | |
81 | linker loaded in for libc.so's "ld.so.1" dep will provide the | |
82 | definition seen by libc.so's initializer; that value must be zero, | |
83 | and will be since that dynamic linker's _dl_start and dl_main will | |
84 | never be called. */ | |
85 | int _dl_starting_up; | |
86 | ||
266180eb RM |
87 | static void dl_main (const ElfW(Phdr) *phdr, |
88 | ElfW(Half) phent, | |
89 | ElfW(Addr) *user_entry); | |
d66e34cd | 90 | |
ee188d55 | 91 | struct link_map _dl_rtld_map; |
c84142e8 | 92 | struct libname_list _dl_rtld_libname; |
f41c8091 | 93 | struct libname_list _dl_rtld_libname2; |
86d2c878 | 94 | |
b1dbbaa4 RM |
95 | #ifdef RTLD_START |
96 | RTLD_START | |
97 | #else | |
98 | #error "sysdeps/MACHINE/dl-machine.h fails to define RTLD_START" | |
99 | #endif | |
100 | ||
ceb2d9aa | 101 | static ElfW(Addr) |
d66e34cd RM |
102 | _dl_start (void *arg) |
103 | { | |
86d2c878 | 104 | struct link_map bootstrap_map; |
d66e34cd | 105 | |
b1dbbaa4 RM |
106 | /* This #define produces dynamic linking inline functions for |
107 | bootstrap relocation instead of general-purpose relocation. */ | |
108 | #define RTLD_BOOTSTRAP | |
c84142e8 | 109 | #define RESOLVE(sym, version, flags) bootstrap_map.l_addr |
b1dbbaa4 RM |
110 | #include "dynamic-link.h" |
111 | ||
d66e34cd | 112 | /* Figure out the run-time load address of the dynamic linker itself. */ |
86d2c878 | 113 | bootstrap_map.l_addr = elf_machine_load_address (); |
d66e34cd | 114 | |
47707456 UD |
115 | /* Read our own dynamic section and fill in the info array. */ |
116 | bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic (); | |
86d2c878 | 117 | elf_get_dynamic_info (bootstrap_map.l_ld, bootstrap_map.l_info); |
d66e34cd RM |
118 | |
119 | #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC | |
86d2c878 | 120 | ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info); |
d66e34cd RM |
121 | #endif |
122 | ||
123 | /* Relocate ourselves so we can do normal function calls and | |
124 | data access using the global offset table. */ | |
421f82e5 | 125 | |
3996f34b | 126 | ELF_DYNAMIC_RELOCATE (&bootstrap_map, 0, 0); |
ea7eb7e3 UD |
127 | /* Please note that we don't allow profiling of this object and |
128 | therefore need not test whether we have to allocate the array | |
129 | for the relocation results (as done in dl-reloc.c). */ | |
421f82e5 | 130 | |
d66e34cd RM |
131 | /* Now life is sane; we can call functions and access global data. |
132 | Set up to use the operating system facilities, and find out from | |
133 | the operating system's program loader where to find the program | |
134 | header table in core. */ | |
135 | ||
86d2c878 | 136 | /* Transfer data about ourselves to the permanent link_map structure. */ |
ee188d55 RM |
137 | _dl_rtld_map.l_addr = bootstrap_map.l_addr; |
138 | _dl_rtld_map.l_ld = bootstrap_map.l_ld; | |
f41c8091 | 139 | _dl_rtld_map.l_opencount = 1; |
ee188d55 RM |
140 | memcpy (_dl_rtld_map.l_info, bootstrap_map.l_info, |
141 | sizeof _dl_rtld_map.l_info); | |
142 | _dl_setup_hash (&_dl_rtld_map); | |
86d2c878 | 143 | |
4cb20290 RM |
144 | /* Cache the DT_RPATH stored in ld.so itself; this will be |
145 | the default search path. */ | |
f41c8091 UD |
146 | if (_dl_rtld_map.l_info[DT_STRTAB] && _dl_rtld_map.l_info[DT_RPATH]) |
147 | { | |
148 | _dl_rpath = (void *) (_dl_rtld_map.l_addr + | |
149 | _dl_rtld_map.l_info[DT_STRTAB]->d_un.d_ptr + | |
150 | _dl_rtld_map.l_info[DT_RPATH]->d_un.d_val); | |
151 | } | |
d66e34cd RM |
152 | |
153 | /* Call the OS-dependent function to set up life so we can do things like | |
154 | file access. It will call `dl_main' (below) to do all the real work | |
155 | of the dynamic linker, and then unwind our frame and run the user | |
156 | entry point on the same stack we entered on. */ | |
8d6468d0 | 157 | return _dl_sysdep_start (arg, &dl_main); |
d66e34cd RM |
158 | } |
159 | ||
d66e34cd RM |
160 | /* Now life is peachy; we can do all normal operations. |
161 | On to the real work. */ | |
162 | ||
f21acc89 | 163 | void ENTRY_POINT (void); |
d66e34cd | 164 | |
993b3242 UD |
165 | /* Some helper functions. */ |
166 | ||
167 | /* Arguments to relocate_doit. */ | |
168 | struct relocate_args | |
169 | { | |
170 | struct link_map *l; | |
171 | int lazy; | |
172 | }; | |
173 | ||
174 | struct map_args | |
175 | { | |
176 | /* Argument to map_doit. */ | |
177 | char *str; | |
178 | /* Return value of map_doit. */ | |
179 | struct link_map *main_map; | |
180 | }; | |
181 | ||
182 | /* Arguments to version_check_doit. */ | |
183 | struct version_check_args | |
184 | { | |
185 | struct link_map *main_map; | |
186 | int doexit; | |
187 | }; | |
188 | ||
189 | static void | |
190 | relocate_doit (void *a) | |
191 | { | |
192 | struct relocate_args *args = (struct relocate_args *) a; | |
193 | ||
194 | _dl_relocate_object (args->l, _dl_object_relocation_scope (args->l), | |
195 | args->lazy); | |
196 | } | |
197 | ||
198 | static void | |
199 | map_doit (void *a) | |
200 | { | |
201 | struct map_args *args = (struct map_args *)a; | |
c6222ab9 | 202 | args->main_map = _dl_map_object (NULL, args->str, 0, lt_library, 0); |
993b3242 UD |
203 | } |
204 | ||
205 | static void | |
206 | version_check_doit (void *a) | |
207 | { | |
208 | struct version_check_args *args = (struct version_check_args *)a; | |
209 | if (_dl_check_all_versions (args->main_map, 1) && args->doexit) | |
210 | /* We cannot start the application. Abort now. */ | |
211 | _exit (1); | |
212 | } | |
213 | ||
ce37fa88 UD |
214 | |
215 | static inline struct link_map * | |
216 | find_needed (const char *name) | |
217 | { | |
218 | unsigned int n; | |
219 | ||
220 | for (n = 0; n < _dl_loaded->l_nsearchlist; ++n) | |
221 | if (_dl_name_match_p (name, _dl_loaded->l_searchlist[n])) | |
222 | return _dl_loaded->l_searchlist[n]; | |
223 | ||
224 | /* Should never happen. */ | |
225 | return NULL; | |
226 | } | |
227 | ||
228 | static int | |
229 | match_version (const char *string, struct link_map *map) | |
230 | { | |
231 | const char *strtab = (const char *) (map->l_addr | |
232 | + map->l_info[DT_STRTAB]->d_un.d_ptr); | |
233 | ElfW(Verdef) *def; | |
234 | ||
235 | #define VERDEFTAG (DT_NUM + DT_PROCNUM + DT_VERSIONTAGIDX (DT_VERDEF)) | |
236 | if (map->l_info[VERDEFTAG] == NULL) | |
237 | /* The file has no symbol versioning. */ | |
238 | return 0; | |
239 | ||
240 | def = (ElfW(Verdef) *) ((char *) map->l_addr | |
241 | + map->l_info[VERDEFTAG]->d_un.d_ptr); | |
242 | while (1) | |
243 | { | |
244 | ElfW(Verdaux) *aux = (ElfW(Verdaux) *) ((char *) def + def->vd_aux); | |
245 | ||
246 | /* Compare the version strings. */ | |
247 | if (strcmp (string, strtab + aux->vda_name) == 0) | |
248 | /* Bingo! */ | |
249 | return 1; | |
250 | ||
251 | /* If no more definitions we failed to find what we want. */ | |
252 | if (def->vd_next == 0) | |
253 | break; | |
254 | ||
255 | /* Next definition. */ | |
256 | def = (ElfW(Verdef) *) ((char *) def + def->vd_next); | |
257 | } | |
258 | ||
259 | return 0; | |
260 | } | |
261 | ||
91f62ce6 | 262 | unsigned int _dl_skip_args; /* Nonzero if we were run directly. */ |
a1a9d215 | 263 | |
d66e34cd | 264 | static void |
266180eb RM |
265 | dl_main (const ElfW(Phdr) *phdr, |
266 | ElfW(Half) phent, | |
267 | ElfW(Addr) *user_entry) | |
d66e34cd | 268 | { |
266180eb | 269 | const ElfW(Phdr) *ph; |
ceb2d9aa | 270 | struct link_map *main_map; |
0200214b | 271 | int lazy; |
ea278354 | 272 | enum mode mode; |
2064087b RM |
273 | struct link_map **preloads; |
274 | unsigned int npreloads; | |
fd26970f | 275 | const char *preloadlist; |
14bab8de UD |
276 | size_t file_size; |
277 | char *file; | |
2f6d1f1b | 278 | int has_interp = 0; |
d66e34cd | 279 | |
ea278354 UD |
280 | /* Process the environment variable which control the behaviour. */ |
281 | process_envvars (&mode, &lazy); | |
3996f34b | 282 | |
46ec036d UD |
283 | /* Set up a flag which tells we are just starting. */ |
284 | _dl_starting_up = 1; | |
285 | ||
f21acc89 | 286 | if (*user_entry == (ElfW(Addr)) &ENTRY_POINT) |
0200214b RM |
287 | { |
288 | /* Ho ho. We are not the program interpreter! We are the program | |
289 | itself! This means someone ran ld.so as a command. Well, that | |
290 | might be convenient to do sometimes. We support it by | |
291 | interpreting the args like this: | |
292 | ||
293 | ld.so PROGRAM ARGS... | |
294 | ||
295 | The first argument is the name of a file containing an ELF | |
296 | executable we will load and run with the following arguments. | |
297 | To simplify life here, PROGRAM is searched for using the | |
298 | normal rules for shared objects, rather than $PATH or anything | |
299 | like that. We just load it and use its entry point; we don't | |
300 | pay attention to its PT_INTERP command (we are the interpreter | |
301 | ourselves). This is an easy way to test a new ld.so before | |
302 | installing it. */ | |
421f82e5 | 303 | |
da832465 UD |
304 | /* Overwrites LD_LIBRARY_PATH if given. */ |
305 | const char *library_path = NULL; | |
306 | ||
ffee1316 RM |
307 | /* Note the place where the dynamic linker actually came from. */ |
308 | _dl_rtld_map.l_name = _dl_argv[0]; | |
6a76c115 | 309 | |
fd26970f UD |
310 | while (_dl_argc > 1) |
311 | if (! strcmp (_dl_argv[1], "--list")) | |
312 | { | |
313 | mode = list; | |
314 | lazy = -1; /* This means do no dependency analysis. */ | |
61965e9b | 315 | |
fd26970f UD |
316 | ++_dl_skip_args; |
317 | --_dl_argc; | |
318 | ++_dl_argv; | |
319 | } | |
320 | else if (! strcmp (_dl_argv[1], "--verify")) | |
321 | { | |
322 | mode = verify; | |
6a76c115 | 323 | |
fd26970f UD |
324 | ++_dl_skip_args; |
325 | --_dl_argc; | |
326 | ++_dl_argv; | |
327 | } | |
880f421f UD |
328 | else if (! strcmp (_dl_argv[1], "--library-path") |
329 | && _dl_argc > 2) | |
330 | { | |
331 | library_path = _dl_argv[2]; | |
332 | ||
333 | _dl_skip_args += 2; | |
334 | _dl_argc -= 2; | |
335 | _dl_argv += 2; | |
336 | } | |
fd26970f UD |
337 | else |
338 | break; | |
d66e34cd | 339 | |
61eb22d3 UD |
340 | /* If we have no further argument the program was called incorrectly. |
341 | Grant the user some education. */ | |
342 | if (_dl_argc < 2) | |
343 | _dl_sysdep_fatal ("\ | |
344 | Usage: ld.so [--list|--verify] EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\ | |
345 | You have invoked `ld.so', the helper program for shared library executables.\n\ | |
346 | This program usually lives in the file `/lib/ld.so', and special directives\n\ | |
347 | in executable files using ELF shared libraries tell the system's program\n\ | |
348 | loader to load the helper program from this file. This helper program loads\n\ | |
349 | the shared libraries needed by the program executable, prepares the program\n\ | |
350 | to run, and runs it. You may invoke this helper program directly from the\n\ | |
351 | command line to load and run an ELF executable file; this is like executing\n\ | |
352 | that file itself, but always uses this helper program from the file you\n\ | |
353 | specified, instead of the helper program file specified in the executable\n\ | |
354 | file you run. This is mostly of use for maintainers to test new versions\n\ | |
355 | of this helper program; chances are you did not intend to run this program.\n", | |
356 | NULL); | |
357 | ||
0200214b RM |
358 | ++_dl_skip_args; |
359 | --_dl_argc; | |
360 | ++_dl_argv; | |
91f62ce6 | 361 | |
da832465 UD |
362 | /* Initialize the data structures for the search paths for shared |
363 | objects. */ | |
364 | _dl_init_paths (library_path); | |
365 | ||
2de99474 UD |
366 | if (mode == verify) |
367 | { | |
dcf0671d | 368 | char *err_str = NULL; |
2de99474 | 369 | const char *obj_name __attribute__ ((unused)); |
993b3242 | 370 | struct map_args args; |
2de99474 | 371 | |
993b3242 UD |
372 | args.str = _dl_argv[0]; |
373 | (void) _dl_catch_error (&err_str, &obj_name, map_doit, &args); | |
374 | main_map = args.main_map; | |
2de99474 | 375 | if (err_str != NULL) |
dcf0671d UD |
376 | { |
377 | free (err_str); | |
378 | _exit (EXIT_FAILURE); | |
379 | } | |
2de99474 UD |
380 | } |
381 | else | |
c6222ab9 | 382 | main_map = _dl_map_object (NULL, _dl_argv[0], 0, lt_library, 0); |
2de99474 | 383 | |
ceb2d9aa UD |
384 | phdr = main_map->l_phdr; |
385 | phent = main_map->l_phnum; | |
386 | main_map->l_name = (char *) ""; | |
387 | *user_entry = main_map->l_entry; | |
0200214b RM |
388 | } |
389 | else | |
390 | { | |
391 | /* Create a link_map for the executable itself. | |
392 | This will be what dlopen on "" returns. */ | |
1618c590 | 393 | main_map = _dl_new_object ((char *) "", "", lt_executable); |
ceb2d9aa | 394 | if (main_map == NULL) |
762a2918 | 395 | _dl_sysdep_fatal ("cannot allocate memory for link map\n", NULL); |
ceb2d9aa UD |
396 | main_map->l_phdr = phdr; |
397 | main_map->l_phnum = phent; | |
398 | main_map->l_entry = *user_entry; | |
3e5f5557 | 399 | main_map->l_opencount = 1; |
da832465 UD |
400 | |
401 | /* Initialize the data structures for the search paths for shared | |
402 | objects. */ | |
403 | _dl_init_paths (NULL); | |
0200214b RM |
404 | } |
405 | ||
406 | /* Scan the program header table for the dynamic section. */ | |
407 | for (ph = phdr; ph < &phdr[phent]; ++ph) | |
408 | switch (ph->p_type) | |
409 | { | |
da832465 UD |
410 | case PT_PHDR: |
411 | /* Find out the load address. */ | |
412 | main_map->l_addr = (ElfW(Addr)) phdr - ph->p_vaddr; | |
413 | break; | |
0200214b RM |
414 | case PT_DYNAMIC: |
415 | /* This tells us where to find the dynamic section, | |
416 | which tells us everything we need to do. */ | |
ceb2d9aa | 417 | main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr; |
0200214b RM |
418 | break; |
419 | case PT_INTERP: | |
420 | /* This "interpreter segment" was used by the program loader to | |
421 | find the program interpreter, which is this program itself, the | |
422 | dynamic linker. We note what name finds us, so that a future | |
423 | dlopen call or DT_NEEDED entry, for something that wants to link | |
424 | against the dynamic linker as a shared library, will know that | |
425 | the shared object is already loaded. */ | |
ceb2d9aa | 426 | _dl_rtld_libname.name = (const char *) main_map->l_addr + ph->p_vaddr; |
c84142e8 UD |
427 | _dl_rtld_libname.next = NULL; |
428 | _dl_rtld_map.l_libname = &_dl_rtld_libname; | |
f41c8091 UD |
429 | |
430 | /* Ordinarilly, we would get additional names for the loader from | |
431 | our DT_SONAME. This can't happen if we were actually linked as | |
432 | a static executable (detect this case when we have no DYNAMIC). | |
433 | If so, assume the filename component of the interpreter path to | |
434 | be our SONAME, and add it to our name list. */ | |
435 | if (_dl_rtld_map.l_ld == NULL) | |
436 | { | |
437 | char *p = strrchr (_dl_rtld_libname.name, '/'); | |
438 | if (p) | |
439 | { | |
440 | _dl_rtld_libname2.name = p+1; | |
441 | _dl_rtld_libname2.next = NULL; | |
442 | _dl_rtld_libname.next = &_dl_rtld_libname2; | |
443 | } | |
444 | } | |
445 | ||
2f6d1f1b | 446 | has_interp = 1; |
0200214b RM |
447 | break; |
448 | } | |
ffee1316 | 449 | if (! _dl_rtld_map.l_libname && _dl_rtld_map.l_name) |
c84142e8 UD |
450 | { |
451 | /* We were invoked directly, so the program might not have a | |
452 | PT_INTERP. */ | |
453 | _dl_rtld_libname.name = _dl_rtld_map.l_name; | |
454 | _dl_rtld_libname.next = NULL; | |
455 | _dl_rtld_map.l_libname = &_dl_rtld_libname; | |
456 | } | |
ffee1316 RM |
457 | else |
458 | assert (_dl_rtld_map.l_libname); /* How else did we get here? */ | |
0200214b | 459 | |
61965e9b RM |
460 | if (mode == verify) |
461 | /* We were called just to verify that this is a dynamic executable | |
462 | using us as the program interpreter. */ | |
ceb2d9aa | 463 | _exit (main_map->l_ld == NULL ? 1 : has_interp ? 0 : 2); |
61965e9b | 464 | |
0200214b | 465 | /* Extract the contents of the dynamic section for easy access. */ |
ceb2d9aa UD |
466 | elf_get_dynamic_info (main_map->l_ld, main_map->l_info); |
467 | if (main_map->l_info[DT_HASH]) | |
0200214b | 468 | /* Set up our cache of pointers into the hash table. */ |
ceb2d9aa | 469 | _dl_setup_hash (main_map); |
0200214b | 470 | |
0200214b | 471 | /* Put the link_map for ourselves on the chain so it can be found by |
ceb2d9aa UD |
472 | name. Note that at this point the global chain of link maps contains |
473 | exactly one element, which is pointed to by main_map. */ | |
ffee1316 RM |
474 | if (! _dl_rtld_map.l_name) |
475 | /* If not invoked directly, the dynamic linker shared object file was | |
476 | found by the PT_INTERP name. */ | |
c84142e8 | 477 | _dl_rtld_map.l_name = (char *) _dl_rtld_map.l_libname->name; |
ba79d61b | 478 | _dl_rtld_map.l_type = lt_library; |
ceb2d9aa UD |
479 | main_map->l_next = &_dl_rtld_map; |
480 | _dl_rtld_map.l_prev = main_map; | |
0200214b | 481 | |
14bab8de UD |
482 | /* We have two ways to specify objects to preload: via environment |
483 | variable and via the file /etc/ld.so.preload. The later can also | |
484 | be used when security is enabled. */ | |
2064087b RM |
485 | preloads = NULL; |
486 | npreloads = 0; | |
14bab8de | 487 | |
fd26970f UD |
488 | preloadlist = getenv ("LD_PRELOAD"); |
489 | if (preloadlist) | |
c4029823 | 490 | { |
566efee2 UD |
491 | /* The LD_PRELOAD environment variable gives list of libraries |
492 | separated by white space or colons that are loaded before the | |
fd26970f UD |
493 | executable's dependencies and prepended to the global scope |
494 | list. If the binary is running setuid all elements | |
495 | containing a '/' are ignored since it is insecure. */ | |
496 | char *list = strdupa (preloadlist); | |
497 | char *p; | |
566efee2 | 498 | while ((p = strsep (&list, " :")) != NULL) |
fd26970f UD |
499 | if (! __libc_enable_secure || strchr (p, '/') == NULL) |
500 | { | |
c6222ab9 UD |
501 | struct link_map *new_map = _dl_map_object (NULL, p, 1, |
502 | lt_library, 0); | |
bd355af0 UD |
503 | if (new_map->l_opencount == 1) |
504 | /* It is no duplicate. */ | |
505 | ++npreloads; | |
fd26970f | 506 | } |
c4029823 UD |
507 | } |
508 | ||
14bab8de UD |
509 | /* Read the contents of the file. */ |
510 | file = _dl_sysdep_read_whole_file ("/etc/ld.so.preload", &file_size, | |
511 | PROT_READ | PROT_WRITE); | |
512 | if (file) | |
513 | { | |
514 | /* Parse the file. It contains names of libraries to be loaded, | |
515 | separated by white spaces or `:'. It may also contain | |
516 | comments introduced by `#'. */ | |
517 | char *problem; | |
518 | char *runp; | |
519 | size_t rest; | |
520 | ||
521 | /* Eliminate comments. */ | |
522 | runp = file; | |
523 | rest = file_size; | |
524 | while (rest > 0) | |
525 | { | |
526 | char *comment = memchr (runp, '#', rest); | |
527 | if (comment == NULL) | |
528 | break; | |
529 | ||
530 | rest -= comment - runp; | |
531 | do | |
532 | *comment = ' '; | |
533 | while (--rest > 0 && *++comment != '\n'); | |
534 | } | |
535 | ||
536 | /* We have one problematic case: if we have a name at the end of | |
537 | the file without a trailing terminating characters, we cannot | |
538 | place the \0. Handle the case separately. */ | |
49891c10 UD |
539 | if (file[file_size - 1] != ' ' && file[file_size - 1] != '\t' |
540 | && file[file_size - 1] != '\n' && file[file_size - 1] != ':') | |
14bab8de UD |
541 | { |
542 | problem = &file[file_size]; | |
543 | while (problem > file && problem[-1] != ' ' && problem[-1] != '\t' | |
49891c10 | 544 | && problem[-1] != '\n' && problem[-1] != ':') |
14bab8de UD |
545 | --problem; |
546 | ||
547 | if (problem > file) | |
548 | problem[-1] = '\0'; | |
549 | } | |
550 | else | |
49891c10 UD |
551 | { |
552 | problem = NULL; | |
553 | file[file_size - 1] = '\0'; | |
554 | } | |
14bab8de UD |
555 | |
556 | if (file != problem) | |
557 | { | |
558 | char *p; | |
49891c10 | 559 | runp = file + strspn (file, ": \t\n"); |
14bab8de UD |
560 | while ((p = strsep (&runp, ": \t\n")) != NULL) |
561 | { | |
c6222ab9 | 562 | struct link_map *new_map = _dl_map_object (NULL, p, 1, |
bd355af0 UD |
563 | lt_library, 0); |
564 | if (new_map->l_opencount == 1) | |
565 | /* It is no duplicate. */ | |
566 | ++npreloads; | |
49891c10 UD |
567 | |
568 | if (runp != NULL) | |
569 | runp += strspn (runp, ": \t\n"); | |
14bab8de UD |
570 | } |
571 | } | |
572 | ||
573 | if (problem != NULL) | |
574 | { | |
575 | char *p = strndupa (problem, file_size - (problem - file)); | |
c6222ab9 UD |
576 | struct link_map *new_map = _dl_map_object (NULL, p, 1, |
577 | lt_library, 0); | |
bd355af0 UD |
578 | if (new_map->l_opencount == 1) |
579 | /* It is no duplicate. */ | |
580 | ++npreloads; | |
14bab8de UD |
581 | } |
582 | ||
583 | /* We don't need the file anymore. */ | |
584 | __munmap (file, file_size); | |
585 | } | |
586 | ||
14bab8de UD |
587 | if (npreloads != 0) |
588 | { | |
589 | /* Set up PRELOADS with a vector of the preloaded libraries. */ | |
590 | struct link_map *l; | |
591 | unsigned int i; | |
592 | preloads = __alloca (npreloads * sizeof preloads[0]); | |
593 | l = _dl_rtld_map.l_next; /* End of the chain before preloads. */ | |
594 | i = 0; | |
595 | do | |
596 | { | |
597 | preloads[i++] = l; | |
598 | l = l->l_next; | |
599 | } while (l); | |
600 | assert (i == npreloads); | |
601 | } | |
602 | ||
2064087b RM |
603 | /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD |
604 | specified some libraries to load, these are inserted before the actual | |
605 | dependencies in the executable's searchlist for symbol resolution. */ | |
ceb2d9aa | 606 | _dl_map_object_deps (main_map, preloads, npreloads, mode == trace); |
d66e34cd | 607 | |
2064087b | 608 | #ifndef MAP_ANON |
f332db02 RM |
609 | /* We are done mapping things, so close the zero-fill descriptor. */ |
610 | __close (_dl_zerofd); | |
611 | _dl_zerofd = -1; | |
2064087b | 612 | #endif |
f332db02 | 613 | |
f9496a7b RM |
614 | /* Remove _dl_rtld_map from the chain. */ |
615 | _dl_rtld_map.l_prev->l_next = _dl_rtld_map.l_next; | |
616 | if (_dl_rtld_map.l_next) | |
617 | _dl_rtld_map.l_next->l_prev = _dl_rtld_map.l_prev; | |
618 | ||
619 | if (_dl_rtld_map.l_opencount) | |
0200214b | 620 | { |
f9496a7b RM |
621 | /* Some DT_NEEDED entry referred to the interpreter object itself, so |
622 | put it back in the list of visible objects. We insert it into the | |
623 | chain in symbol search order because gdb uses the chain's order as | |
624 | its symbol search order. */ | |
625 | unsigned int i = 1; | |
ceb2d9aa | 626 | while (main_map->l_searchlist[i] != &_dl_rtld_map) |
f9496a7b | 627 | ++i; |
ceb2d9aa UD |
628 | _dl_rtld_map.l_prev = main_map->l_searchlist[i - 1]; |
629 | _dl_rtld_map.l_next = (i + 1 < main_map->l_nsearchlist ? | |
630 | main_map->l_searchlist[i + 1] : NULL); | |
f9496a7b RM |
631 | assert (_dl_rtld_map.l_prev->l_next == _dl_rtld_map.l_next); |
632 | _dl_rtld_map.l_prev->l_next = &_dl_rtld_map; | |
4d02a5b1 | 633 | if (_dl_rtld_map.l_next) |
f9496a7b RM |
634 | { |
635 | assert (_dl_rtld_map.l_next->l_prev == _dl_rtld_map.l_prev); | |
636 | _dl_rtld_map.l_next->l_prev = &_dl_rtld_map; | |
637 | } | |
0200214b | 638 | } |
d66e34cd | 639 | |
c84142e8 UD |
640 | /* Now let us see whether all libraries are available in the |
641 | versions we need. */ | |
642 | { | |
993b3242 UD |
643 | struct version_check_args args; |
644 | args.doexit = mode == normal; | |
645 | args.main_map = main_map; | |
646 | _dl_receive_error (print_missing_version, version_check_doit, &args); | |
c84142e8 UD |
647 | } |
648 | ||
2de99474 | 649 | if (mode != normal) |
0200214b RM |
650 | { |
651 | /* We were run just to list the shared libraries. It is | |
652 | important that we do this before real relocation, because the | |
653 | functions we call below for output may no longer work properly | |
654 | after relocation. */ | |
1a3a58fd | 655 | |
0200214b | 656 | int i; |
fd861379 | 657 | |
0200214b RM |
658 | if (! _dl_loaded->l_info[DT_NEEDED]) |
659 | _dl_sysdep_message ("\t", "statically linked\n", NULL); | |
660 | else | |
ceb2d9aa UD |
661 | { |
662 | struct link_map *l; | |
663 | ||
664 | for (l = _dl_loaded->l_next; l; l = l->l_next) | |
665 | if (l->l_opencount == 0) | |
666 | /* The library was not found. */ | |
667 | _dl_sysdep_message ("\t", l->l_libname->name, " => not found\n", | |
668 | NULL); | |
669 | else | |
670 | { | |
671 | char buf[20], *bp; | |
672 | buf[sizeof buf - 1] = '\0'; | |
af6f3906 | 673 | bp = _itoa_word (l->l_addr, &buf[sizeof buf - 1], 16, 0); |
ceb2d9aa UD |
674 | while ((size_t) (&buf[sizeof buf - 1] - bp) |
675 | < sizeof l->l_addr * 2) | |
676 | *--bp = '0'; | |
677 | _dl_sysdep_message ("\t", l->l_libname->name, " => ", | |
678 | l->l_name, " (0x", bp, ")\n", NULL); | |
679 | } | |
680 | } | |
1a3a58fd | 681 | |
2de99474 | 682 | if (mode != trace) |
cddcfecf RM |
683 | for (i = 1; i < _dl_argc; ++i) |
684 | { | |
685 | const ElfW(Sym) *ref = NULL; | |
686 | ElfW(Addr) loadbase = _dl_lookup_symbol (_dl_argv[i], &ref, | |
687 | &_dl_default_scope[2], | |
dcf0671d | 688 | "argument", |
a2b08ee5 | 689 | ELF_MACHINE_JMP_SLOT); |
cddcfecf RM |
690 | char buf[20], *bp; |
691 | buf[sizeof buf - 1] = '\0'; | |
af6f3906 | 692 | bp = _itoa_word (ref->st_value, &buf[sizeof buf - 1], 16, 0); |
14bab8de | 693 | while ((size_t) (&buf[sizeof buf - 1] - bp) < sizeof loadbase * 2) |
cddcfecf RM |
694 | *--bp = '0'; |
695 | _dl_sysdep_message (_dl_argv[i], " found at 0x", bp, NULL); | |
696 | buf[sizeof buf - 1] = '\0'; | |
af6f3906 | 697 | bp = _itoa_word (loadbase, &buf[sizeof buf - 1], 16, 0); |
14bab8de | 698 | while ((size_t) (&buf[sizeof buf - 1] - bp) < sizeof loadbase * 2) |
cddcfecf RM |
699 | *--bp = '0'; |
700 | _dl_sysdep_message (" in object at 0x", bp, "\n", NULL); | |
701 | } | |
ce37fa88 | 702 | else |
fd26970f | 703 | { |
ce37fa88 UD |
704 | if (lazy >= 0) |
705 | { | |
706 | /* We have to do symbol dependency testing. */ | |
707 | struct relocate_args args; | |
708 | struct link_map *l; | |
993b3242 | 709 | |
ce37fa88 | 710 | args.lazy = lazy; |
fd26970f | 711 | |
ce37fa88 UD |
712 | l = _dl_loaded; |
713 | while (l->l_next) | |
714 | l = l->l_next; | |
715 | do | |
716 | { | |
717 | if (l != &_dl_rtld_map && l->l_opencount > 0) | |
718 | { | |
719 | args.l = l; | |
720 | _dl_receive_error (print_unresolved, relocate_doit, | |
721 | &args); | |
722 | *_dl_global_scope_end = NULL; | |
723 | } | |
724 | l = l->l_prev; | |
725 | } while (l); | |
726 | } | |
727 | ||
728 | #define VERNEEDTAG (DT_NUM + DT_PROCNUM + DT_VERSIONTAGIDX (DT_VERNEED)) | |
729 | if (*(getenv ("LD_VERBOSE") ?: "") != '\0') | |
fd26970f | 730 | { |
ce37fa88 UD |
731 | /* Print more information. This means here, print information |
732 | about the versions needed. */ | |
733 | int first = 1; | |
734 | struct link_map *map = _dl_loaded; | |
735 | ||
736 | for (map = _dl_loaded; map != NULL; map = map->l_next) | |
fd26970f | 737 | { |
f41c8091 | 738 | const char *strtab; |
ce37fa88 | 739 | ElfW(Dyn) *dyn = map->l_info[VERNEEDTAG]; |
f41c8091 UD |
740 | ElfW(Verneed) *ent; |
741 | ||
742 | if (dyn == NULL) | |
743 | continue; | |
744 | ||
745 | strtab = (const char *) | |
746 | (map->l_addr + map->l_info[DT_STRTAB]->d_un.d_ptr); | |
747 | ent = (ElfW(Verneed) *) (map->l_addr + dyn->d_un.d_ptr); | |
ce37fa88 | 748 | |
f41c8091 | 749 | if (first) |
ce37fa88 | 750 | { |
f41c8091 UD |
751 | _dl_sysdep_message ("\n\tVersion information:\n", NULL); |
752 | first = 0; | |
753 | } | |
ce37fa88 | 754 | |
f41c8091 UD |
755 | _dl_sysdep_message ("\t", (map->l_name[0] |
756 | ? map->l_name : _dl_argv[0]), | |
757 | ":\n", NULL); | |
758 | ||
759 | while (1) | |
760 | { | |
761 | ElfW(Vernaux) *aux; | |
762 | struct link_map *needed; | |
ce37fa88 | 763 | |
f41c8091 UD |
764 | needed = find_needed (strtab + ent->vn_file); |
765 | aux = (ElfW(Vernaux) *) ((char *) ent + ent->vn_aux); | |
ce37fa88 UD |
766 | |
767 | while (1) | |
768 | { | |
f41c8091 UD |
769 | const char *fname = NULL; |
770 | ||
771 | _dl_sysdep_message ("\t\t", | |
772 | strtab + ent->vn_file, | |
773 | " (", strtab + aux->vna_name, | |
774 | ") ", | |
775 | (aux->vna_flags | |
776 | & VER_FLG_WEAK | |
777 | ? "[WEAK] " : ""), | |
778 | "=> ", NULL); | |
779 | ||
780 | if (needed != NULL | |
781 | && match_version (strtab+aux->vna_name, needed)) | |
782 | fname = needed->l_name; | |
783 | ||
784 | _dl_sysdep_message (fname ?: "not found", "\n", | |
785 | NULL); | |
ce37fa88 | 786 | |
f41c8091 UD |
787 | if (aux->vna_next == 0) |
788 | /* No more symbols. */ | |
ce37fa88 UD |
789 | break; |
790 | ||
f41c8091 UD |
791 | /* Next symbol. */ |
792 | aux = (ElfW(Vernaux) *) ((char *) aux | |
793 | + aux->vna_next); | |
ce37fa88 | 794 | } |
f41c8091 UD |
795 | |
796 | if (ent->vn_next == 0) | |
797 | /* No more dependencies. */ | |
798 | break; | |
799 | ||
800 | /* Next dependency. */ | |
801 | ent = (ElfW(Verneed) *) ((char *) ent + ent->vn_next); | |
ce37fa88 | 802 | } |
fd26970f | 803 | } |
ce37fa88 | 804 | } |
fd26970f | 805 | } |
d66e34cd | 806 | |
0200214b RM |
807 | _exit (0); |
808 | } | |
86d2c878 | 809 | |
ba79d61b RM |
810 | { |
811 | /* Now we have all the objects loaded. Relocate them all except for | |
812 | the dynamic linker itself. We do this in reverse order so that copy | |
813 | relocs of earlier objects overwrite the data written by later | |
814 | objects. We do not re-relocate the dynamic linker itself in this | |
815 | loop because that could result in the GOT entries for functions we | |
816 | call being changed, and that would break us. It is safe to relocate | |
817 | the dynamic linker out of order because it has no copy relocs (we | |
818 | know that because it is self-contained). */ | |
819 | ||
ceb2d9aa | 820 | struct link_map *l; |
ba79d61b RM |
821 | l = _dl_loaded; |
822 | while (l->l_next) | |
823 | l = l->l_next; | |
824 | do | |
825 | { | |
826 | if (l != &_dl_rtld_map) | |
827 | { | |
828 | _dl_relocate_object (l, _dl_object_relocation_scope (l), lazy); | |
829 | *_dl_global_scope_end = NULL; | |
830 | } | |
831 | l = l->l_prev; | |
832 | } while (l); | |
833 | ||
834 | /* Do any necessary cleanups for the startup OS interface code. | |
835 | We do these now so that no calls are made after rtld re-relocation | |
836 | which might be resolved to different functions than we expect. | |
837 | We cannot do this before relocating the other objects because | |
838 | _dl_relocate_object might need to call `mprotect' for DT_TEXTREL. */ | |
839 | _dl_sysdep_start_cleanup (); | |
840 | ||
841 | if (_dl_rtld_map.l_opencount > 0) | |
842 | /* There was an explicit ref to the dynamic linker as a shared lib. | |
843 | Re-relocate ourselves with user-controlled symbol definitions. */ | |
844 | _dl_relocate_object (&_dl_rtld_map, &_dl_default_scope[2], 0); | |
845 | } | |
0200214b | 846 | |
4d6acc61 RM |
847 | { |
848 | /* Initialize _r_debug. */ | |
849 | struct r_debug *r = _dl_debug_initialize (_dl_rtld_map.l_addr); | |
ceb2d9aa | 850 | struct link_map *l; |
4d6acc61 RM |
851 | |
852 | l = _dl_loaded; | |
ec42724d RM |
853 | |
854 | #ifdef ELF_MACHINE_DEBUG_SETUP | |
855 | ||
856 | /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way. */ | |
857 | ||
858 | ELF_MACHINE_DEBUG_SETUP (l, r); | |
859 | ELF_MACHINE_DEBUG_SETUP (&_dl_rtld_map, r); | |
860 | ||
861 | #else | |
862 | ||
4d6acc61 RM |
863 | if (l->l_info[DT_DEBUG]) |
864 | /* There is a DT_DEBUG entry in the dynamic section. Fill it in | |
865 | with the run-time address of the r_debug structure */ | |
866 | l->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r; | |
867 | ||
d746b89c RM |
868 | /* Fill in the pointer in the dynamic linker's own dynamic section, in |
869 | case you run gdb on the dynamic linker directly. */ | |
870 | if (_dl_rtld_map.l_info[DT_DEBUG]) | |
871 | _dl_rtld_map.l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r; | |
872 | ||
ec42724d RM |
873 | #endif |
874 | ||
4d6acc61 RM |
875 | /* Notify the debugger that all objects are now mapped in. */ |
876 | r->r_state = RT_ADD; | |
877 | _dl_debug_state (); | |
878 | } | |
0200214b | 879 | |
3996f34b UD |
880 | /* Now enable profiling if needed. */ |
881 | if (_dl_profile_map != NULL) | |
882 | /* We must prepare the profiling. */ | |
883 | _dl_start_profile (_dl_profile_map, _dl_profile_output); | |
884 | ||
d66e34cd RM |
885 | /* Once we return, _dl_sysdep_start will invoke |
886 | the DT_INIT functions and then *USER_ENTRY. */ | |
887 | } | |
fd26970f UD |
888 | \f |
889 | /* This is a little helper function for resolving symbols while | |
890 | tracing the binary. */ | |
891 | static void | |
c84142e8 UD |
892 | print_unresolved (int errcode __attribute__ ((unused)), const char *objname, |
893 | const char *errstring) | |
fd26970f | 894 | { |
3996f34b UD |
895 | if (objname[0] == '\0') |
896 | objname = _dl_argv[0] ?: "<main program>"; | |
fd26970f UD |
897 | _dl_sysdep_error (errstring, " (", objname, ")\n", NULL); |
898 | } | |
c84142e8 UD |
899 | \f |
900 | /* This is a little helper function for resolving symbols while | |
901 | tracing the binary. */ | |
902 | static void | |
903 | print_missing_version (int errcode __attribute__ ((unused)), | |
904 | const char *objname, const char *errstring) | |
905 | { | |
906 | _dl_sysdep_error (_dl_argv[0] ?: "<program name unknown>", ": ", | |
907 | objname, ": ", errstring, "\n", NULL); | |
908 | } | |
ea278354 | 909 | \f |
b5efde2f UD |
910 | /* Process the string given as the parameter which explains which debugging |
911 | options are enabled. */ | |
912 | static void | |
913 | process_dl_debug (char *dl_debug) | |
914 | { | |
915 | do | |
916 | { | |
917 | #define issep(Ch) ((Ch) == ' ' || (Ch) == ',') | |
918 | /* Skip separating white spaces and commas. */ | |
919 | while (issep (*dl_debug)) | |
920 | ++dl_debug; | |
921 | if (*dl_debug != '\0') | |
922 | { | |
923 | if (strncmp (dl_debug, "libs", 4) == 0 | |
924 | && (issep (dl_debug[4]) || dl_debug[4] == '\0')) | |
925 | { | |
926 | _dl_debug_libs = 1; | |
927 | dl_debug += 4; | |
928 | } | |
929 | else if (strncmp (dl_debug, "help", 4) == 0 | |
930 | && (issep (dl_debug[4]) || dl_debug[4] == '\0')) | |
931 | { | |
932 | _dl_sysdep_message ("\ | |
933 | Valid options for the DL_DEBUG environment variable are:\n\ | |
934 | \n\ | |
935 | help display this help message and exit | |
936 | libs display library search paths\n", NULL); | |
937 | _exit (0); | |
938 | } | |
939 | else | |
940 | /* Skip everything until next separator. */ | |
941 | do | |
942 | ++dl_debug; | |
943 | while (*dl_debug != '\0' && !issep (*dl_debug)); | |
944 | } | |
945 | } | |
946 | while (*dl_debug != '\0'); | |
947 | } | |
948 | \f | |
ea278354 UD |
949 | /* Process all environments variables the dynamic linker must recognize. |
950 | Since all of them start with `LD_' we are a bit smarter while finding | |
951 | all the entries. */ | |
952 | static void | |
953 | process_envvars (enum mode *modep, int *lazyp) | |
954 | { | |
955 | char **runp = NULL; | |
956 | char *envline; | |
957 | enum mode mode = normal; | |
958 | int bind_now = 0; | |
959 | ||
960 | /* This is the default place for profiling data file. */ | |
961 | _dl_profile_output = "/var/tmp"; | |
962 | ||
963 | while ((envline = _dl_next_ld_env_entry (&runp)) != NULL) | |
964 | { | |
965 | int result; | |
966 | ||
967 | /* Do we bind early? */ | |
968 | result = strncmp (&envline[3], "BIND_NOW=", 9); | |
969 | if (result == 0) | |
970 | { | |
971 | bind_now = 1; | |
972 | continue; | |
973 | } | |
974 | if (result < 0) | |
975 | continue; | |
976 | ||
b5efde2f UD |
977 | /* Debugging of the dynamic linker? */ |
978 | result = strncmp (&envline[3], "DEBUG=", 6); | |
979 | if (result == 0) | |
980 | { | |
981 | process_dl_debug (&envline[9]); | |
982 | continue; | |
983 | } | |
984 | if (result < 0) | |
985 | continue; | |
986 | ||
ea278354 UD |
987 | /* Which shared object shall be profiled. */ |
988 | result = strncmp (&envline[3], "PROFILE=", 8); | |
989 | if (result == 0) | |
990 | { | |
991 | _dl_profile = &envline[11]; | |
992 | if (*_dl_profile == '\0') | |
993 | _dl_profile = NULL; | |
994 | continue; | |
995 | } | |
996 | if (result < 0) | |
997 | continue; | |
998 | ||
999 | /* Where to place the profiling data file. */ | |
1000 | result = strncmp (&envline[3], "PROFILE_OUTPUT=", 15); | |
1001 | if (result == 0) | |
1002 | { | |
1003 | _dl_profile_output = &envline[18]; | |
1004 | if (*_dl_profile_output == '\0') | |
1005 | _dl_profile_output = "/var/tmp"; | |
1006 | continue; | |
1007 | } | |
1008 | if (result < 0) | |
1009 | continue; | |
1010 | ||
1011 | /* Test whether we want to see the content of the auxiliary | |
1012 | array passed up from the kernel. */ | |
1013 | result = strncmp (&envline[3], "SHOW_AUXV=", 10); | |
1014 | if (result == 0) | |
1015 | { | |
1016 | _dl_show_auxv (); | |
1017 | continue; | |
1018 | } | |
1019 | if (result < 0) | |
1020 | continue; | |
1021 | ||
1022 | /* The mode of the dynamic linker can be set. */ | |
1023 | result = strncmp (&envline[3], "TRACE_LOADED_OBJECTS=", 21); | |
1024 | if (result == 0) | |
1025 | { | |
1026 | mode = trace; | |
1027 | continue; | |
1028 | } | |
1029 | if (result < 0) | |
1030 | continue; | |
1031 | ||
1032 | /* Warning level, verbose or not. */ | |
1033 | result = strncmp (&envline[3], "WARN=", 5); | |
1034 | if (result == 0) | |
1035 | { | |
1036 | _dl_verbose = envline[8] != '\0'; | |
1037 | continue; | |
1038 | } | |
1039 | } | |
1040 | ||
1041 | /* LAZY is determined by the environment variable LD_WARN and | |
1042 | LD_BIND_NOW if we trace the binary. */ | |
1043 | if (mode == trace) | |
1044 | *lazyp = _dl_verbose ? !bind_now : -1; | |
1045 | else | |
1046 | *lazyp = !__libc_enable_secure && !bind_now; | |
1047 | ||
1048 | *modep = mode; | |
1049 | } |