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